Category Archives: EGFR

Retinoids

Cancer: none noted

Action: Down-regulates,epidermal growth factor receptor

Human papillomavirus (HPV) is an important etiological agent in the genesis of cervical cancer. HPV-positive cervical tumors and human papillomavirus-positive cell lines display increased epidermal growth factor receptor (EGFR) expression, which is associated with increased cell proliferation. ECE16-1 cells are an HPV-immortalized human ectocervical epithelial cell line that is a model of HPV-associated cervical neoplasia and displays elevated EGFR levels.

The effects of receptor-selective retinoid ligands on EGFR-associated signal transduction were examined. It has been shown that retinoic acid receptor (RAR)-selective ligands reduce EGFR level and the magnitude and duration of EGFR activation in EGF-stimulated cells.

These effects are reversed by co-treatment with an RAR antagonist. To identify the mechanism, Sah et al. (2002) examined the effects of retinoid treatments on EGF-dependent signaling. Stimulation with EGF causes a biphasic activation of the ERK1/2 MAPK.

This effect is specific as retinoid treatment does not alter the level or activity of other EGFR-regulated kinases, including AKT and the MAPKs p38 and JNK. Retinoid X receptor-selective ligands, in contrast, did not regulate these responses. These results suggest that RAR ligand-associated down-regulation of EGFR activity reduces cell proliferation by reducing the magnitude and duration of EGF-dependent ERK1/2 activation.

All-trans retinoic acid (RA), through binding to the retinoic acid receptors (RARs), alters interactions of the RARs with various protein components of the transcription complex at numerous genes in stem cells, and some of these protein components of the transcription complex then either place or remove epigenetic marks on histones or on DNA, altering chromatin structure and leading to an exit from the self-renewing, pluripotent stem cell state.

Different epigenetic mechanisms, i.e. first, primarily H3K27me3 marks and then DNA methylation, may be employed by embryonic stem cells and other stem cells for control of early vs. late stages of cell differentiation. Creating these stable epigenetic changes requires the actions of many molecules, including tet1, polycomb protein complexes (PRCs), miRNAs, DNA methyltransferases (DNMTs), and telomerase reverse transcriptase (Gudas, 2013).

References

Gudas LJ. (2013). Retinoids induce stem cell differentiation via epigenetic changes. Semin Cell Dev Biol, S1084-9521(13)00102-X. doi: 10.1016/j.semcdb.2013.08.002.


Sah JF, Eckert RL, Chandraratna RA, Rorke EA. (2002). Retinoids suppress epidermal growth factor-associated cell proliferation by inhibiting epidermal growth factor receptor-dependent ERK1/2 activation. J Biol Chem, 277(12):9728-35.

Geraniin

Cancer: Melanoma, T cell leukemia, cervical

Action: Causes cell-cycle arrest

Melanoma

Geraniin, a form of tannin separated from Geranium genus (including Geranium niveum (S. Watson)), causes cell death through induction of apoptosis. Geraniin triggered cell death by caspase-3-mediated cleavage of FAK and was associated with the up-regulation of Fas ligand expression, the activation of caspase-8, the cleavage of Bid, and the induction of cytochrome c release from mitochondria to the cytosol in human melanoma cells (Lee et al., 2008).

Leukemia, Cervical Cancer

Different concentrations of geraniin, the level of expression of the client proteins c-Raf, pAkt, and EGFR, was strongly down-regulated. Geraniin was able to inhibit in vitro the Hsp90α ATPase activity in a dose-dependent manner, with an inhibitory efficiency comparable to that measured for 17-AAG. In addition, this compound compromised the chaperone activity of Hsp90α, monitored by the citrate synthase thermal induced aggregation assay. Geraniin decreased the viability of HeLa and Jurkat cell lines and caused an arrest in G2/M phase. These results, along with the finding that geraniin did not exert any appreciable cytotoxicity on normal cells, encourage further studies on this compound as a promising chemical scaffold for the design of new Hsp90 inhibitors (Vassallo et al., 2013).

References

Lee JC, Tsai CY, Kao JY, et al. (2008). Geraniin-mediated apoptosis by cleavage of focal adhesion kinase through up-regulation of Fas ligand expression in human melanoma cells. Mol Nutr Food Res, 52(6):655-63.


Vassallo A, Vaccaro MC, De Tommasi N, Dal Piaz F, Leone A. (2013). Identification of the plant compound geraniin as a novel hsp90 inhibitor. PLoS One, 8(9):e74266. doi: 10.1371/journal.pone.0074266.

Dietary Flavones

Cancer:
Prostate, colorectal., breast, pancreatic, bladder, ovarian, leukemia, liver, glioma, osteosarcoma, melanoma

Action: Anti-inflammatory, TAM resistance, cancer stem cells, down-regulate COX-2, apoptosis, cell-cycle arrest, anti-angiogenic, chemo-sensitzer, adramycin (ADM) resistance

Sulforaphane, Phenethyl isothiocyanate (PEITC), quercetin, epicatechin, catechin, Luteolin, apigenin

Anti-inflammatory

The anti-inflammatory activities of celery extracts, some rich in flavone aglycones and others rich in flavone glycosides, were tested on the inflammatory mediators tumor necrosis factor α (TNF-α) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) in lipopolysaccharide-stimulated macrophages. Pure flavone aglycones and aglycone-rich extracts effectively reduced TNF-α production and inhibited the transcriptional activity of NF-κB, while glycoside-rich extracts showed no significant effects.

Celery diets with different glycoside or aglycone contents were formulated and absorption was evaluated in mice fed with 5% or 10% celery diets. Relative absorption in vivo was significantly higher in mice fed with aglycone-rich diets as determined by HPLC-MS/MS (where MS/MS is tandem mass spectrometry). These results demonstrate that deglycosylation increases absorption of dietary flavones in vivo and modulates inflammation by reducing TNF-α and NF-κB, suggesting the potential use of functional foods rich in flavones for the treatment and prevention of inflammatory diseases (Hostetler et al., 2012).

Colorectal Cancer

Association between the 6 main classes of flavonoids and the risk of colorectal cancer was examined using data from a national prospective case-control study in Scotland, including 1,456 incident cases and 1,456 population-based controls matched on age, sex, and residence area.

Dietary, including flavonoid, data were obtained from a validated, self-administered food frequency questionnaire. Risk of colorectal cancer was estimated using conditional logistic regression models in the whole sample and stratified by sex, smoking status, and cancer site and adjusted for established and putative risk factors.

The significant dose-dependent reductions in colorectal cancer risk that were associated with increased consumption of the flavonols quercetin, catechin, and epicatechin, remained robust after controlling for overall fruit and vegetable consumption or for other flavonoid intake. The risk reductions were greater among nonsmokers, but no interaction beyond a multiplicative effect was present.

This was the first of several a priori hypotheses to be tested in this large study and showed strong and linear inverse associations of flavonoids with colorectal cancer risk (Theodoratou et al., 2007).

Anti-angiogenic, Prostate Cancer

Luteolin is a common dietary flavonoid found in fruits and vegetables. The anti-angiogenic activity of luteolin was examined using in vitro, ex vivo, and in vivo models. Angiogenesis, the formation of new blood vessels from pre-existing vascular beds, is essential for tumor growth, invasion, and metastasis; hence, examination of this mechanism of tumor growth is essential to understanding new chemo-preventive targets. In vitro studies using rat aortic ring assay showed that luteolin at non-toxic concentrations significantly inhibited microvessel sprouting and proliferation, migration, invasion and tube formation of endothelial cells, which are key events in the process of angiogenesis. Luteolin also inhibited ex vivo angiogenesis as revealed by chicken egg chorioallantoic membrane assay (CAM) and matrigel plug assay.

Pro-inflammatory cytokines such as IL-1β, IL-6, IL-8, and TNF-α level were significantly reduced by the treatment of luteolin in PC-3 cells. Luteolin (10 mg/kg/d) significantly reduced the volume and the weight of solid tumors in prostate xenograft mouse model, indicating that luteolin inhibited tumorigenesis by targeting angiogenesis. Moreover, luteolin reduced cell viability and induced apoptosis in prostate cancer cells, which were correlated with the down-regulation of AKT, ERK, mTOR, P70S6K, MMP-2, and MMP-9 expressions.

Taken together, these findings demonstrate that luteolin inhibits human prostate tumor growth by suppressing vascular endothelial growth factor receptor 2-mediated angiogenesis (Pratheeshkumar et al., 2012).

Pancreatic Cancer; Chemo-sensitizer

The potential of dietary flavonoids apigenin (Api) and luteolin (Lut) were assessed in their ability to enhance the anti-proliferative effects of chemotherapeutic drugs on BxPC-3 human pancreatic cancer cells; additionally, the molecular mechanism of the action was probed.

Simultaneous treatment with either flavonoid (0,13, 25 or 50µM) and chemotherapeutic drugs 5-fluorouracil (5-FU, 50µM) or gemcitabine (Gem, 10µM) for 60 hours resulted in less-than-additive effect (p<0.05). Pre-treatment for 24 hours with 13µM of either Api or Lut, followed by Gem for 36 hours was optimal to inhibit cell proliferation. Pre-treatment of cells with 11-19µM of either flavonoid for 24 hours resulted in 59-73% growth inhibition when followed by Gem (10µM, 36h). Lut (15µM, 24h) pre-treatment followed by Gem (10µM, 36h), significantly decreased protein expression of nuclear GSK-3β and NF-κB p65 and increased pro-apoptotic cytosolic cytochrome c. Pre-treatment of human pancreatic cancer cells BxPC-3 with low concentrations of Api or Lut hence effectively aid in the anti-proliferative activity of chemotherapeutic drugs (Johnson et al., 2013).

Breast Cancer; Chemo-sensitizer, Tamoxifen

The oncogenic molecules in human breast cancer cells are inhibited by luteolin treatment and it was found that the level of cyclin E2 (CCNE2) mRNA was higher in tumor cells than in normal paired tissue samples as assessed using real-time reverse-transcriptase polymerase chain reaction (RT-PCR) analysis (n=257).

Combined treatment with 4-OH-TAM and luteolin synergistically sensitized the TAM-R cells to 4-OH-TAM. These results suggest that luteolin can be used as a chemo-sensitizer to target the expression level of CCNE2 and that it could be a novel strategy to overcome TAM resistance in breast cancer patients (Tu et al., 2013).

Breast Cancer

Consumers of higher levels of Brassica vegetables, particularly those of the genus Brassica (broccoli, Brussels sprouts and cabbage), reduce their susceptibility to cancer at a variety of organ sites. Brassica vegetables contain high concentrations of glucosinolates that can be hydrolyzed by the plant enzyme, myrosinase, or intestinal microflora to isothiocyanates, potent inducers of cytoprotective enzymes and inhibitors of carcinogenesis. Oral administration of either the isothiocyanate, sulforaphane, or its glucosinolate precursor, glucoraphanin, inhibits mammary carcinogenesis in rats treated with 7,12-dimethylbenz[a]anthracene. To determine whether sulforaphane exerts a direct chemo-preventive action on animal and human mammary tissue, the pharmacokinetics and pharmacodynamics of a single 150 µmol oral dose of sulforaphane were evaluated in the rat mammary gland.

Sulforaphane metabolites were detected at concentrations known to alter gene expression in cell culture. Elevated cytoprotective NAD(P)H:quinone oxidoreductase (NQO1) and heme oxygenase-1 (HO-1) gene transcripts were measured using quantitative real-time polymerase chain reaction. An observed 3-fold increase in NQO1 enzymatic activity, as well as 4-fold elevated immunostaining of HO-1 in rat mammary epithelium, provide strong evidence of a pronounced pharmacodynamic action of sulforaphane. In a subsequent pilot study, eight healthy women undergoing reduction mammoplasty were given a single dose of a broccoli sprout preparation containing 200 µmol of sulforaphane. Following oral dosing, sulforaphane metabolites were readily measurable in human breast tissue enriched for epithelial cells. These findings provide a strong rationale for evaluating the protective effects of a broccoli sprout preparation in clinical trials of women at risk for breast cancer (Cornblatt et al., 2007).

In a proof of principle clinical study, the presence of disseminated tumor cells (DTCs) was demonstrated in human breast tissue after a single dose of a broccoli sprout preparation containing 200 µmol of sulforaphane. Together, these studies demonstrate that sulforaphane distributes to the breast epithelial cells in vivo and exerts a pharmacodynamic action in these target cells consistent with its mechanism of chemo-protective efficacy.

Such efficacy, coupled with earlier randomized clinical trials revealing the safety of repeated doses of broccoli sprout preparations , supports further evaluation of broccoli sprouts in the chemoprevention of breast and other cancers (Cornblatt et al., 2007).

CSCs

Recent research into the effects of sulforaphane on cancer stem cells (CSCs) has drawn a great deal of interest. CSCs are suggested to be responsible for initiating and maintaining cancer, and to contribute to recurrence and drug resistance. A number of studies have indicated that sulforaphane may target CSCs in different types of cancer through modulation of NF- κB, SHH, epithelial-mesenchymal transition and Wnt/β-catenin pathways. Combination therapy with sulforaphane and chemotherapy in preclinical settings has shown promising results (Li et al., 2013).

Anti-inflammatory

Sulforaphane has been found to down-regulate COX-2 expression in human bladder transitional cancer T24 cells at both transcriptional- and translational levels. Cyclooxygenase-2 (COX-2) overexpression has been associated with the grade, prognosis and recurrence of transitional cell carcinoma (TCC) of the bladder. Sulforaphane (5-20 microM) induced nuclear translocation of NF-kappaB and reduced its binding to the COX-2 promoter, a key mechanism for suppressing COX-2 expression by sulforaphane. Moreover, sulforaphane increased expression of p38 and phosphorylated-p38 protein. Taken together, these data suggest that p38 is essential in sulforaphane-mediated COX-2 suppression and provide new insights into the molecular mechanisms of sulforaphane in the chemoprevention of bladder cancer (Shan et al., 2009).

Bladder Cancer

An aqueous extract of broccoli sprouts potently inhibits the growth of human bladder carcinoma cells in culture and this inhibition is almost exclusively due to the isothiocyanates. Isothiocyanates are present in broccoli sprouts as their glucosinolate precursors and blocking their conversion to isothiocyanates abolishes the anti-proliferative activity of the extract.

Moreover, the potency of isothiocyanates in the extract in inhibiting cancer cell growth was almost identical to that of synthetic sulforaphane, as judged by their IC50 values (6.6 versus 6.8 micromol/L), suggesting that other isothiocyanates in the extract may be biologically similar to sulforaphane and that nonisothiocyanate substances in the extract may not interfere with the anti-proliferative activity of the isothiocyanates. These data show that broccoli sprout isothiocyanate extract is a highly promising substance for cancer prevention/treatment and that its anti-proliferative activity is exclusively derived from isothiocyanates (Tang et al., 2006).

Ovarian Cancer

Sulforaphane is an extract from the mustard family recognized for its anti-oxidation abilities, phase 2 enzyme induction, and anti-tumor activity. The cell-cycle arrest in G2/M by sulforaphane and the expression of cyclin B1, Cdc2, and the cyclin B1/CDC2 complex in PA-1 cells using Western blotting and co-IP Western blotting. The anti-cancer effects of dietary isothiocyanate sulforaphane on ovarian cancer were investigated using cancer cells line PA-1.

Sulforaphane -treated cells accumulated in metaphase by CDC2 down-regulation and dissociation of the cyclin B1/CDC2 complex.

These findings suggest that, in addition to the known effects on cancer prevention, sulforaphane may also provide anti-tumor activity in established ovarian cancer (Chang et al., 2013).

Leukemia Stem Cells

Isolated leukemia stem cells (LSCs) showed high expression of Oct4, CD133, β-catenin, and Sox2 and imatinib (IM) resistance. Differentially, CD34(+)/CD38(-) LSCs demonstrated higher BCR-ABL and β-catenin expression and IM resistance than CD34(+)/CD38(+) counterparts. IM and sulforaphane (SFN) combined treatment sensitized CD34(+)/CD38(-) LSCs and induced apoptosis, shown by increased caspase 3, PARP, and Bax while decreased Bcl-2 expression. Mechanistically, imatinib (IM) and sulforaphane (SFN) combined treatment resensitized LSCs by inducing intracellular reactive oxygen species (ROS). Importantly, β-catenin-silenced LSCs exhibited reduced glutathione S-transferase pi 1 (GSTP1) expression and intracellular GSH level, which led to increased sensitivity toward IM and sulforaphane.

It was hence demonstrated that IM and sulforaphane combined treatment effectively eliminated CD34(+)/CD38(-) LSCs. Since SFN has been shown to be well tolerated in both animals and human, this regimen could be considered for clinical trials (Lin et al., 2012).

DCIS Stem Cells

A miR-140/ALDH1/SOX9 axis has been found to be critical to basal cancer stem cell self-renewal and tumor formation in vivo, suggesting that the miR-140 pathway may be a promising target for preventive strategies in patients with basal-like Ductal Carcinoma in Situ (DCIS). The dietary compound sulforaphane has been found to decrease Transcription factor SOX-9 and Acetaldehyde dehydrogenases (ALDH1), and thereby reduced tumor growth in vivo (Li et al., 2013).

Glioma, Prostate Cancer, Colon Cancer, Breast Cancer, Liver Cancer

Phenethyl isothiocyanate (PEITC), a natural dietary isothiocyanate, inhibits angiogenesis. The effects of PEITC were examined under hypoxic conditions on the intracellular level of the hypoxia inducible factor (HIF-1α) and extracellular level of the vascular endothelial growth factor (VEGF) in a variety of human cancer cell lines. Gupta et al., (2013) observed that PEITC suppressed the HIF-1α accumulation during hypoxia in human glioma U87, human prostate cancer DU145, colon cancer HCT116, liver cancer HepG2, and breast cancer SkBr3 cells. PEITC treatment also significantly reduced the hypoxia-induced secretion of VEGF.

Suppression of HIF-1α accumulation during treatment with PEITC in hypoxia was related to PI3K and MAPK pathways.

Taken together, these results suggest that PEITC inhibits the HIF-1α expression through inhibiting the PI3K and MAPK signaling pathway and provide a new insight into a potential mechanism of the anti-cancer properties of PEITC.

Breast Cancer Metastasis

Breast tumor metastasis is a leading cause of cancer-related deaths worldwide. Breast tumor cells frequently metastasize to brain and initiate severe therapeutic complications. The chances of brain metastasis are further elevated in patients with HER2 overexpression. The MDA-MB-231-BR (BR-brain seeking) breast tumor cells stably transfected with luciferase were injected into the left ventricle of mouse heart and the migration of cells to brain was monitored using a non-invasive IVIS bio-luminescent imaging system.

Results demonstrate that the growth of metastatic brain tumors in PEITC treated mice was about 50% less than that of control. According to Kaplan Meir's curve, median survival of tumor-bearing mice treated with PEITC was prolonged by 20.5%. Furthermore, as compared to controls, we observed reduced HER2, EGFR and VEGF expression in the brain sections of PEITC treated mice. These results demonstrate the anti-metastatic effects of PEITC in vivo in a novel breast tumor metastasis model and provides the rationale for further clinical investigation (Gupta et al., 2013).

Osteosarcoma, Melanoma

Phenethyl isothiocyanate (PEITC) has been found to induce apoptosis in human osteosarcoma U-2 OS cells. The following end points were determined in regard to human malignant melanoma cancer A375.S2 cells: cell morphological changes, cell-cycle arrest, DNA damage and fragmentation assays and morphological assessment of nuclear change, reactive oxygen species (ROS) and Ca2+ generations, mitochondrial membrane potential disruption, and nitric oxide and 10-N-nonyl acridine orange productions, expression and activation of caspase-3 and -9, B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax), Bcl-2, poly (adenosine diphosphate-ribose) polymerase, and cytochrome c release, apoptosis-inducing factor and endonuclease G. PEITC

It was therefore concluded that PEITC-triggered apoptotic death in A375.S2 cells occurs through ROS-mediated mitochondria-dependent pathways (Huang et al., 2013).

Prostate Cancer

The glucosinolate-derived phenethyl isothiocyanate (PEITC) has recently been demonstrated to reduce the risk of prostate cancer (PCa) and inhibit PCa cell growth. It has been shown that p300/CBP-associated factor (PCAF), a co-regulator for the androgen receptor (AR), is upregulated in PCa cells through suppression of the mir-17 gene. Using AR-responsive LNCaP cells, the inhibitory effects of PEITC were observed on the dihydrotestosterone-stimulated AR transcriptional activity and cell growth of PCa cells.

Expression of PCAF was upregulated in PCa cells through suppression of miR-17. PEITC treatment significantly decreased PCAF expression and promoted transcription of miR-17 in LNCaP cells. Functional inhibition of miR-17 attenuated the suppression of PCAF in cells treated by PEITC. Results indicate that PEITC inhibits AR-regulated transcriptional activity and cell growth of PCa cells through miR-17-mediated suppression of PCAF, suggesting a new mechanism by which PEITC modulates PCa cell growth (Yu et al., 2013).

Bladder Cancer; Adramycin (ADM) Resistance

The role of PEITC on ADM resistance reversal of human bladder carcinoma T24/ADM cells has been examined, including an increased drug sensitivity to ADM, cell apoptosis rates, intracellular accumulation of Rhodamine-123 (Rh-123), an increased expression of DNA topoisomerase II (Topo-II), and a decreased expression of multi-drug resistance gene (MDR1), multi-drug resistance-associated protein (MRP1), bcl-2 and glutathione s transferase π (GST-π). The results indicated that PEITC might be used as a potential therapeutic strategy to ADM resistance through blocking Akt and activating MAPK pathway in human bladder carcinoma (Tang et al., 2013).

Breast Cancer; Chemo-enhancing

The synergistic effect between paclitaxel (taxol) and phenethyl isothiocyanate (PEITC) on the inhibition of breast cancer cells has been examined. Two drug-resistant breast cancer cell lines, MCF7 and MDA-MB-231, were treated with PEITC and taxol. Cell growth, cell-cycle, and apoptosis were examined.

The combination of PEITC and taxol significantly decreased the IC50 of PEITC and taxol over each agent alone. The combination also increased apoptosis by more than 2-fold over each single agent in both cell lines. A significant increase of cells in the G2/M phases was detected. Taken together, these results indicated that the combination of PEITC and taxol exhibits a synergistic effect on growth inhibition in breast cancer cells. This combination deserves further study in vivo (Liu et al., 2013).

References

Chang CC, Hung CM, Yang YR, Lee MJ, Hsu YC. (2013). Sulforaphane induced cell-cycle arrest in the G2/M phase via the blockade of cyclin B1/CDC2 in human ovarian cancer cells. J Ovarian Res, 6(1):41. doi: 10.1186/1757-2215-6-41


Cornblatt BS, Ye LX, Dinkova-Kostova AT, et al. (2007). Preclinical and clinical evaluation of sulforaphane for chemoprevention in the breast. Carcinogenesis, 28(7):1485-1490. doi: 10.1093/carcin/bgm049


Gupta B, Chiang L, Chae K, Lee DH. (2013). Phenethyl isothiocyanate inhibits hypoxia-induced accumulation of HIF-1 α and VEGF expression in human glioma cells. Food Chem, 141(3):1841-6. doi: 10.1016/j.foodchem.2013.05.006.


Gupta P, Adkins C, Lockman P, Srivastava SK. (2013). Metastasis of Breast Tumor Cells to Brain Is Suppressed by Phenethyl Isothiocyanate in a Novel In Vivo Metastasis Model. PLoS One, 8(6):e67278. doi:10.1371/journal.pone.0067278


Hostetler G, Riedl K, Cardenas H, et al. (2012). Flavone deglycosylation increases their anti-inflammatory activity and absorption. Molecular Nutrition & Food Research, 56(4):558-569. doi: 10.1002/mnfr.201100596


Huang SH, Hsu MH, Hsu SC, et al. (2013). Phenethyl isothiocyanate triggers apoptosis in human malignant melanoma A375.S2 cells through reactive oxygen species and the mitochondria-dependent pathways. Hum Exp Toxicol. doi: 10.1177/0960327113491508


Johnson JL, Gonzalez de Mejia E. (2013). Interactions between dietary flavonoids apigenin or luteolin and chemotherapeutic drugs to potentiate anti-proliferative effect on human pancreatic cancer cells, in vitro. Food Chem Toxicol, 60:83-91. doi: 10.1016/j.fct.2013.07.036.


Li Q, Yao Y, Eades G, Liu Z, Zhang Y, Zhou Q. (2013). Down-regulation of miR-140 promotes cancer stem cell formation in basal-like early stage breast cancer. Oncogene. doi: 10.1038/onc.2013.226.


Li Y, Zhang T. (2013). Targeting cancer stem cells with sulforaphane, a dietary component from broccoli and broccoli sprouts. Future Oncol, 9(8):1097-103. doi: 10.2217/fon.13.108.


Lin LC, Yeh CT, Kuo CC, et al. (2012). Sulforaphane potentiates the efficacy of imatinib against chronic leukemia cancer stem cells through enhanced abrogation of Wnt/ β-catenin function. J Agric Food Chem, 60(28):7031-9. doi: 10.1021/jf301981n.


Liu K, Cang S, Ma Y, Chiao JW. (2013). Synergistic effect of paclitaxel and epigenetic agent phenethyl isothiocyanate on growth inhibition, cell-cycle arrest and apoptosis in breast cancer cells. Cancer Cell Int, 13(1):10. doi: 10.1186/1475-2867-13-10.


Pratheeshkumar P, Son YO, Budhraja A, et al. (2012). Luteolin inhibits human prostate tumor growth by suppressing vascular endothelial growth factor receptor 2-mediated angiogenesis. PLoS One, 7(12):52279. doi: 10.1371/journal.pone.0052279.


Tang K, Lin Y, Li LM. (2013). The role of phenethyl isothiocyanate on bladder cancer ADM resistance reversal and its molecular mechanism. Anat Rec (Hoboken), 296(6):899-906. doi: 10.1002/ar.22677.


Tang L, Zhang Y, Jobson HE, et al. (2006). Potent activation of mitochondria-mediated apoptosis and arrest in S and M phases of cancer cells by a broccoli sprout extract. Mol Cancer Ther, 5(4):935-44. doi: 10.1158/1535-7163.MCT-05-0476


Theodoratou E, Kyle J, Cetnarskyj R, et al. (2007). Dietary flavonoids and the risk of colorectal cancer. Cancer Epidemiol Biomarkers Prev,16(4):684-93.


Tu SH, Ho CT, Liu MF, et al. (2013). Luteolin sensitizes drug-resistant human breast cancer cells to tamoxifen via the inhibition of cyclin E2 expression. Food Chem, 141(2):1553-61. doi: 10.1016/j.foodchem.2013.04.077.


Shan Y, Wu K, Wang W, et al. (2009). Sulforaphane down-regulates COX-2 expression by activating p38 and inhibiting NF-kappaB-DNA-binding activity in human bladder T24 cells. Int J Oncol, 34(4):1129-34.


Yu C, Gong AY, Chen D, et al. (2013). Phenethyl isothiocyanate inhibits androgen receptor-regulated transcriptional activity in prostate cancer cells through suppressing PCAF. Mol Nutr Food Res. doi: 10.1002/mnfr.201200810.

Kanglaite injection (KLT)

Cancer: Lung, stomach, liver, kidney, breast, nasopharynx, esophagus, pancreas, colon-rectum, ovarian, prostate, lymphoma, leukemia

Action: Anti-tumoral, immunomodular, chemotherapy support, radiation support

Ingredients: yi yi ren (Coix Lacryma-jobi seed oil, CLSO).

Indications: primary NSCLC and primary liver cancer, which are not suitable for surgery, of qi and yin deficiency, lingering “Dampness due to Spleen deficiency types”. It has synergic effect when combined with radiotherapy or chemotherapy. It has certain anti-cachexia and analgesic effects for middle or late-stage tumor patients.

Dosage and usage:

Slow intravenous drip: 200 ml, once daily, 21 days as a course of treatment with 3-5 days interval.

When combined with radiotherapy or chemotherapy, the dosage can be reduced according to the practical conditions. (Drug Information Reference in Chinese, 2000. See end).

Invented by the famous pharmacological professor, Prof. Li Dapeng, Kanglaite Injection (KLT) has been listed by the Chinese government as a “State Basic Drug”, a “State Basic Medical Insurance Drug” and a “State Key New Drug”.

Based on pre-clinical studies at John Hopkins University, USA, tumor-inhibitive rate of KLT on transplanted breast carcinoma induced by cell strain MDA-MB-231 was over 50%. KLT could inhibit the expression of COX2 of the strain in vitro and act as an inhibitor of fatty acid synthase.

The broad ranged basic studies in China also revealed KLT different mechanisms such as inducing cancer cell apoptosis, inhibiting angiogenesis, reversing MDR and regulating gene expression of Fas/Apo-1 and Bcl-2.

Both Chinese and overseas clinical experiences have shown that KLT has proven effect in the treatment of cancers mainly at the sites of lung, breast, liver, nasopharynx, esophagus, stomach, pancreas, kidney, colon-rectum, ovary and prostate. This agent is also applied in the treatment of malignant lymphoma and acute leukemia. KLT has brought great benefits to over 500,000 cancer patients in more than 2,000 big or medium hospitals in China since 1997.

The year 1995 witnessed KLT patent certificates granted from China and the USA. In August 1997 the phase III clinical study was successfully completed and the injection was officially launched in China after final approval from the Ministry of Public Health.

Doctors in America carried out a phase 1 study of Kanglaite in 2003. They gave it to 16 people who had different types of cancer including lung, prostate and oesophageal cancers. The results showed people did not have many side-effects but the effect on their cancer varied. Some people showed no response, and their cancers continued to grow. But in others, the cancer stopped growing for a few months.

Standard treatment course for KLT is 200 ml (2 bottles) per day via intravenous drip x 42 days (84 bottles). There is a break for 4-5 days after 21 days. Clinical experiences in China and Russia suggest 2 treatment courses for those with late stage advanced and metastatic tumors for better therapeutic effect and evident prolongation of life (Conti, n.d.).

A consecutive cohort of 60 patients was divided into two groups, the experimental group receiving Kanglaite” Injection combined with chemotherapy and the control group receiving chemotherapy alone. After more than two courses of treatment, efficacy, quality of life and side-effects were evaluated. The response rate and KPS score of the experimental group were significantly improved as compared with those of the control group(P<0.05). In addition, gastrointestinal reactions and bone marrow suppression were significantly lower than in the control group(P<0.05). Kanglaite” Injection enhanced efficacy and reduced the side-effects of chemotherapy, improving quality of life of gastric cancer patients (Zhan et al., 2012).

Lung Cancer

C57BL/6 mice with Lewis lung carcinoma were divided into four groups: the control group (C), cisplatin group (1 mg/kg, DDP), low KLT group (6.25 ml/kg body weight [L]), and high KLT group (12.5 ml/kg body weight [H]). T cell proliferation was determined by the MTT assay. Nuclear factor-kappa B (NF-κB), inhibitor kappa B alpha

(IκBα), IκB kinase (IKK) and epidermal growth factor receptor (EGFR) levels were measured by western blotting. An enzyme-linked immunosorbent assay was used to analyze the expression of interleukin-2 (IL-2).

Intraperitoneal KLT significantly inhibited the growth of Lewis lung carcinoma, and the spleen index was significantly higher in the L and H groups than in the C group. KLT stimulated T cell proliferation in a dose-dependent manner. Treatment with KLT at either 6.25 or 12.5 ml/kg decreased the level of NF-κB in the nucleus in a dose-dependent manner, and KLT markedly decreased the expression of IκBα, IKK and EGFR in the cytoplasm of tumor cells and overall. IL-2 was significantly increased in the supernatant of splenocytes in the H group.

These results demonstrate that KLT has pronounced anti-tumor and immunostimulatory activities in C57BL/6 mice with Lewis lung carcinoma. These may affect the regulation of NF-κB/IκB expression, in addition to cytokines such as IL-2 and EGFR. Further work needs to investigate the relevant signaling pathway effects, but our findings suggest that KLT may be a promising anti-tumor drug for clinical use (Pan et al., 2012).

Skin Keratinocytes

Ultraviolet (UV) radiation plays an important role in the pathogenesis of skin photoaging. Depending on the wavelength of UV, the epidermis is affected primarily by UVB. One major characteristic of photoaging is the dehydration of the skin. Membrane-inserted water channels (aquaporins) are involved in this process. In this study we demonstrated that UVB radiation induced aquaporin-3 (AQP3) down-regulation in cultured human skin keratinocytes. Kanglaite is a mixture consisting of extractions of Coix Seed, which is an effective anti-neoplastic agent and can inhibit the activities of protein kinase C and NF-κB. We demonstrated that Kanglaite inhibited UVB-induced AQP3 down-regulation of cultured human skin keratinocytes. Our findings provide a potential new agent for anti-photoaging (Shan et al., 2012).

Hepatocellular Carcinoma

KLT produced an obvious time and dose-dependent inhibitory effect on HepG2 cells, and marked apoptosis was detected by FCM. The protein of Fas increased by 11.01%, 18.71%, 28.71% and 37.15%; the protein of FasL increased by 1.49%, 1.91%, 3.27% and 3.38% in comparison with the control (P<0.05). Real-time fluorescent quantitative RT-PCR showed that treating HepG2 cells with KLT caused the up-regulation of Fas and FasL mRNA. KLT inhibits HepG2 growth by inducing apoptosis, which may be mediated through activation of the Fas/FasL pathway (Lu et al., 2009).

Glomerular Nephritis

MTT, telomere repeat amplification protocol (TRAP), ELISA, PAGE and silver-stain were applied to detect the growth rate and telomerase activity of mesengial cell (MC) after stimulation of Kang Lai Te (KLT) and IL-1. The growth rate of MC was enhanced by IL-1 stimulation, which was accompanied with a reduction of the activity of telomerase. Adversely, the growth rate of MC was reduced by KLT, which was accompanied with an enhancement of activity of telomerase. Moreover, the growth rate of MC and the activity of telomerase were both inhibited by the combinative use of IL-1 and KLT without any influence from the sequence of their administration. KLT could inhibit proliferation and telomerase activity of MC with or without pre-stimulation with IL-1. KLT might be useful to prevent and treat glomerular nephritis related to MC proliferation (Hu et al., 2005).

Lung Metastasis

To screen the differential expression genes of Kanglaite in anti-tumor metastasis mRNA was extracted and purified from the lung of the mouse with LA795 lung metastasis, and hybridized respectively on 4 096-gene chip. cDNA microarray was scanned for the fluorescent signals and analyzing difference expression. Twenty-seven differential expressed genes were obtained.

Among these genes, 25 were up-regulated and 2 were down-regulated. Twelve of them were Mus musculus cDNA clone. Six genes related with genesis, development and metastasis of tumor. cDNA microarray for analysis of gene expression patterns is a powerful method to identify differential expressed genes. In this study, 6 genes are thought to be associated genes of Kanglaite in anti-tumor metastasis (Wu et al., 2003).

Lung Cancer; Chemo Side Effects

Sixteen reports were included in the meta-analysis. The quality of 16 studies was low. Pooling data of 5 studies indicated that the effect of Kanglaite+NP (Vinorelbine+Cisplatin) was better than NP with RR 1.46, 95% Confidence Interval 1.13 to 1.91. Pooling data of 3 studies of MVP (Mitomycin+Vindsine+ Cisplatin) plus Kanglaite indicated that the effect was better with RR 1.84, 95%CI 1.22 to 2.76. Pooling data of 2 studies showed that the effect of GP (Gemcitabine+Cisplatin) plus Kanglaite was better than GP with RR 1.63, 95%CI 1.09 to 2.43.

Fourteen studies revealed that Kanglaite may reduce the side-effects induced by regular treatment. Ten studies showed regular treatment plus Kanglaite can stabilize/improve quality of life (Zhu et al., 2009).

Apoptosis

Some studies show Kanglaite could inhibit some anti-apoptotic genes and activate some pro-apoptotic genes. Its injection solution is one of the new anti-cancer medicines that can significantly inhibit various kinds of tumor cells, so it has become the core of research into how to further explore KLT injection to promote tumor cell apoptosis by impacting on related genes (Lu et al., 2008).

References

Conti, M. (n.d.). Anti-cancer Chinese herbal kanglaite. Cancer Evolution. Retrieved from: http://www.cancerevolution.info/cancer-therapies/alternative-therapies/83-anticancer-chinese-herbal-kanglaite.html.


Hu, Y,H., Liang, W.K. Gong, Z.F. Xu,Q.L. Zou. (2005). The effect of kanglaite injection (KLT) on the proliferation and telomerase activity of rat mesangial cells. Zhongguo Zhong Yao Za Zhi, 30(6):450-453.


Lu, Y., Li, C.S., Dong, Q. (2008) Chinese herb related molecules of cancer-cell-apoptosis: a mini-review of progress between Kanglaite injection and related genes. J Exp Clin Cancer Res, 27:31. doi: 10.1186/1756-9966-27-31.


Lu, Y., L.Q. Wu, Q. Dong,C.S. Li. (2009). Experimental study on the effect of Kang-Lai-Te induced apoptosis of human hepatoma carcinoma cell HepG2. Hepatobiliary Pancreat Dis Int, 8(3):267-272.


Pan, P.,Y. Wu,Z.Y. Guo,R. et al. (2012). Anti-tumor activity and immunomodulatory effects of the intraperitoneal administration of Kanglaite in vivo in Lewis lung carcinoma. J Ethnopharmacol, 143(2):680-685.


Shan, S.J., Xiao T., Chen J., et al. (2012). Kanglaite attenuates UVB-induced down-regulation of aquaporin-3 in cultured human skin keratinocytes. Int J Mol Med, 29(4):625-629.


Wu, Y., Yang Y., Wu D. (2003). Study on the gene expression patterns of Kanglaite in anti-lung metastasis of LA795 mouse. Zhongguo Fei Ai Za Zhi, 6(6):473-476.


Zhan, Y.P., Huang X.E., Cao J. (2012). Clinical safety and efficacy of Kanglaite(R) (Coix Seed Oil) injection combined with chemotherapy in treating patients with gastric cancer. Asian Pac J Cancer Prev, 13(10):5319-5321.


Zhu, L.Z. Yang, S. Wang, Y. Tang. (2009). Kanglaite for Treating Advanced Non-small-cell Lung Cancer: A Systematic Review. Zhongguo Fei Ai Za Zhi, 12(3):208-215.

Silibinin

Cancer:
Lung, leukemia, colorectal, thyroid, breast, bladder

Action: Anti-angiogenesis, EMT, cell-cycle arrest

Cell-cycle Arrest, Colon Cancer

Silibinin, an active constituent of milk thistle (Silybum marianum [(L.) Gaertn.]), has been reported to inhibit proliferation and induce cell-cycle arrest of human colon cancer cells, Fet, Geo, and HCT116 (Hogan et al., 2007). Silibinin Up-regulates the expression of cyclin-dependent kinase inhibitors and induces cell-cycle arrest and apoptosis in human colon carcinoma HT-29 cells (Agarwal et al., 2003). Also in HT-29 cells, treatment with beta-escin, a principal component of horse chestnut, tinduces growth arrest at the G1-S phase together with an induction of Cip1/p21 and an associated reduction in the phosphorylation of retinoblastoma protein (Patlolla et al., 2006).

Lung Cancer

Silibinin also has anti-angiogenic effects on lung adenocarcinomas in vitro, as it strongly decreased both tumor number and tumor size (an anti-tumor effect that correlates with reduced anti-angiogenic activity) (Tyagi et al., 2009). Further, silibinin inhibits mouse lung tumorigenesis in vivo, in part by targeting tumor microenvironment. Tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ) can be pro- or anti-tumorigenic, but in lung cancer cell lines they induce pro-inflammatory enzymes cyclooxygenase 2 (COX2) and inducible nitric oxide synthase (iNOS). Accordingly, the mechanism of silibinin action was examined on TNF-α + IFN-γ (hereafter referred as cytokine mixture) elicited signaling in tumor-derived mouse lung epithelial LM2 cells.

Both signal transducers and activators of the transcription (STAT)3 (tyr705 and ser727) and STAT1 (tyr701) were activated within 15 min of cytokine mixture exposure, while STAT1 (ser727) activated after 3 h. Cytokine mixture also activated Erk1/2 and caused an increase in both COX2 and iNOS levels. Pre-treatment of cells with a MEK, NF-κB, and/or epidermal growth factor receptor (EGFR) inhibitor inhibited cytokine mixture-induced activation of Erk1/2, NF-κB, or EGFR, respectively, and strongly decreased phosphorylation of STAT3 and STAT1 and expression of COX2 and iNOS.

Together, the results show that STAT3 and STAT1 could be valuable chemo-preventive and therapeutic targets within the lung tumor microenvironment in addition to being targets within the tumor itself, and that silibinin inhibit their activation as a plausible mechanism of its efficacy against lung cancer (Tyagi et al., 2011).

Leukemia

Silibinin also affects cellular differentiation in the human promyelocytic leukemia HL-60 cell culture system. Treatment of HL-60 cells with silibinin inhibited cellular proliferation and induced cellular differentiation in a dose-dependent manner.

Silibinin enhanced protein kinase C (PKC) activity and increased protein levels of both PKCα and PKCβ in 1,25-(OH)2D3-treated HL-60 cells. PKC and extracellular signal-regulated kinase (ERK) inhibitors significantly inhibited HL-60 cell differentiation induced by silibinin alone or in combination with 1,25-(OH)2D3, indicating that PKC and ERK may be involved in silibinin-induced HL-60 cell differentiation (Kang et al., 2001).

Thyroid Cancer, Breast Cancer

Silibinin inhibits TPA-induced cell migration and MMP-9 expression in thyroid and breast cancer cells. Matrix metalloproteinases (MMPs) play an important role in cancer metastasis, cell migration and invasion. The effects of silibinin were investigated on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced cell migration and MMP-9 expression in thyroid and breast cancer cells. These results revealed that the levels of MMP-9 mRNA and protein expression were significantly increased by TPA but not MMP-2 in TPC-1 and MCF7 cells.

TPA-induced phosphorylation of MEK and ERK was also inhibited by silibinin. Taken together, these results suggest that silibinin suppresses TPA-induced cell migration and MMP-9 expression through the MEK/ERK-dependent pathway in thyroid and breast cancer cells (Oh et al., 2013).

Bladder Cancer

Silibinin induced apoptosis and inhibited proliferation of bladder cancer cells and metastasis. In the present study, Wu et al. (2013) utilized a novel highly metastatic T24-L cell model, and found that silibinin treatment not only resulted in the suppression of cell migration and invasion in vitro, but also decreased bladder cancer lung metastasis and prolonged animal survival in vivo. Inactivation of β-catenin/ZEB1 signaling by silibinin leads to dual-block of EMT and stemness.

Lung Cancer, EMT

Silibinin formulation might facilitate the design of clinical trials to test the administration of silibinin meglumine-containing injections, granules, or beverages in combination with EGFR TKIs in patients with EGFR-mutated NSCLC. Silibinin meglumine notably decreased the overall volumes of NSCLC tumors as efficiently as did the EGFR tyrosine kinase inhibitor (TKI) gefitinib. Concurrent treatment with silibinin meglumine impeded the regrowth of gefitinib-unresponsive tumors, resulting in drastic tumor growth prevention.

Because the epithelial-to-mesenchymal transition (EMT) is required by a multiplicity of mechanisms of resistance to EGFR TKIs, we evaluated the ability of silibinin meglumine to impede the EMT in vitro and in vivo. Silibinin-meglumine efficiently prevented the loss of markers associated with a polarized epithelial phenotype as well as the de novo synthesis of proteins associated with the mesenchymal morphology of transitioning cells (Cuf` et al., 2013).

Breast cancer

Myeloid-derived suppressor cells (MDSC)s increase in blood and accumulate in the tumor microenvironment of tumor-bearing animals, contributing to immune suppression in cancer. Silibinin, a natural flavonoid from the seeds of milk thistle, has been developed as an anti-inflammatory agent and supportive care agent to reduce the toxicity of cancer chemotherapy. The goals of this study were to evaluate the effect of silibinin on MDSCs in tumor-bearing mice and antitumor activity of silibinin in a mouse model of breast cancer. 4T1 luciferase-transfected mammary carcinoma cells were injected into in the mammary fat pad female BALB/c mice, and female CB17-Prkdc Scid/J mice. Silibinin treatment started on day 4 or day 14 after tumor inoculation continued every other day.

Tumor growth was monitored by bioluminescent imaging (BLI) measuring total photon flux. Flow cytometry measured total leukocytes, CD11b+ Gr-1+ MDSC, and T cells in the blood and tumors of tumor-bearing mice. The effects of silibinin on 4T1 cell viability in vitro were measured by BLI. Treatment with silibinin increased overall survival in mice harboring tumors derived from the 4T1-luciferase breast cancer cell line, and reduced tumor volumes and numbers of CD11b+Gr-1+ MDSCs in the blood and tumor, and increased the content of T cells in the tumor microenvironment.

Silibinin failed to inhibit tumor growth in immunocompromised severe combined immunodeficiency mice, supporting the hypothesis that anticancer effect of silibinin is immune-mediated. The antitumor activity of silibinin requires an intact host immune system and is associated with decreased accumulation of blood and tumor-associated MDSCs.

References

 

Agarwal C, Singh RP, Dhanalakshmi S, et al. (2003). Silibinin Up-regulates the expression of cyclin-dependent kinase inhibitors and causes cell-cycle arrest and apoptosis in human colon carcinoma HT-29 cells. Oncogene, 22:8271–8282.

 

Cufí S, Bonavia R, Vazquez-Martin A, Corominas-Faja B, et al. (2013). Silibinin meglumine, a water-soluble form of milk thistle silymarin, is an orally active anti-cancer agent that impedes the epithelial-to-mesenchymal transition (EMT) in EGFR-mutant non-small-cell lung carcinoma cells. Food Chem Toxicol, 60:360-8. doi: 10.1016/j.fct.2013.07.063.

Hogan FS, Krishnegowda NK, Mikhailova M, Kahlenberg MS. (2007). Flavonoid, silibinin, inhibits proliferation and promotes cell-cycle arrest of human colon cancer. J Surg Res, 143:58–65.

Kang SN, Lee MH, Kim KM, Cho D, Kim TS. (2001). Induction of human promyelocytic leukemia HL-60 cell differentiation into monocytes by silibinin: involvement of protein kinase C. Biochemical Pharmacology, 61(12):1487–1495

Oh SJ, Jung SP, Han J, et al. (2013). Silibinin inhibits TPA-induced cell migration and MMP-9 expression in thyroid and breast cancer cells. Oncol Rep, 29(4):1343-8. doi: 10.3892/or.2013.2252.

Patlolla JM, Raju J, Swamy MV, Rao CV. (2006). Beta-escin inhibits colonic aberrant crypt foci formation in rats and regulates the Cell-cycle growth by inducing p21(waf1/cip1) in colon cancer cells. Mol Cancer Ther, 5:1459–1466.

Tyagi A, Singh RP, Ramasamy K, et al. (2009). Growth Inhibition and Regression of Lung Tumors by Silibinin: Modulation of Angiogenesis by Macrophage-Associated Cytokines and Nuclear Factor-κ B and Signal Transducers and Activators of Transcription 3. Cancer Prev Res, 2(1):74-83

Tyagi A, Agarwal C, Dwyer-Nield LD, et al. (2011). Silibinin modulates TNF‐α and IFN ‐γ mediated signaling to regulate COX2 and iNOS expression in tumorigenic mouse lung epithelial LM2 cells. Molecular Carcinogenesis. doi: 10.1002/mc.20851.

Wu K, Ning Z, Zeng J, et al. (2013). Silibinin inhibits β -catenin/ZEB1 signaling and suppresses bladder cancer metastasis via dual-blocking epithelial-mesenchymal transition and stemness. Cell Signal, 25(12):2625-2633. doi: 10.1016/j.cellsig.2013.08.028.

Forghani P, Khorramizadeh MR & Waller EK. (2014) Silibinin inhibits accumulation of myeloid-derived suppressor cells and tumor growth of murine breast cancer. Cancer Medicine. Volume 3, Issue 2, pages 215–224, April 2014 DOI: 10.1002/cam4.186

Green Tea 95% Polyphenols

Cancer: Lung, colorectal., head and neck

Action: Hemoprevention, chemo-preventive effects

Green tea polyphenols include compounds found in fruits and vegetables, particularly green tea Camellia sinensis [(L.) Kuntze].

Chemo-preventive Effects

Polyphenolic compounds in fruits and vegetables have been associated with lower risk of some diseases, including cancer. Recent research has shown that the polyphenolic anti-oxidants in green tea possess cancer chemo-preventive effects (Ahmad et al., 1999).

Green tea polyphenols were found to increase the activities of glutathione peroxidase, catalase, and quinone reductase in small bowel, liver, and lungs, and glutathione S-transferase in small bowel and liver. These can be implicated in relation to the cancer chemo-preventive effects of green tea polyphenols against the induction of tumors in various target organs (Khan et al., 1992).

Head and Neck Cancers

Additionally, green tea polyphenol-induced production of H2O2 may mediate apoptosis and this may also contribute to the growth-inhibitory activities in cancer cells in vitro (Yang et al., 1998).

A synergistic inhibition between green tea (-)-epigallocatechin-3-gallate and EGFR tyrosine kinase inhibitor in head and neck tumor growth was shown (Zhang et al., 2008).

References

Ahmad N, Mukhtar H. (1999). Green Tea Polyphenols and Cancer: Biologic Mechanisms and Practical Implications. Nutrition Reviews, 57(3), 78-83.


Khan SG, Katiyar SK, Agarwal R, Mukhtar H. (1992). Enhancement of Anti-oxidant and Phase II Enzymes by Oral Feeding of Green Tea Polyphenols in Drinking Water to SKH-1 Hairless Mice: Possible Role in Cancer Chemoprevention. Cancer Research, 52(14), 4050-4052.


Yang GY, Liao J, Kim K, Yurkow EJ, Yang CS. (1998). Inhibition of growth and induction of apoptosis in human cancer cell lines by tea polyphenols. Carcinogenesis, 19(4), 611-616.


Zhang X, Zhang H, Tighiouart M, Lee JE, et al. (2008). Synergistic inhibition of head and neck tumor growth by green tea (-)-epigallocatechin-3-gallate and EGFR tyrosine kinase inhibitor. Int. J. Cancer, 123(5):1005–1014

Curcumin

Cancer: Colorectal., prostate, pancreatic

Action: MDR, chemo-preventive activity, anti-inflammatory, attenuation of immune suppression

Chemo-preventive Activity

Curcumin is a naturally occurring, dietary polyphenolic phytochemical that is under preclinical trial evaluation for cancer-preventive drug development. It is derived from the rhizome of Curcuma longa L. and has both anti-oxidant and anti-inflammatory properties; it inhibits chemically-induced carcinogenesis in the skin, forestomach, and colon when it is administered during initiation and/or postinitiation stages. Chemo-preventive activity of curcumin is observed when it is administered prior to, during, and after carcinogen treatment as well as when it is given only during the promotion/progression phase (starting late in premalignant stage) of colon carcinogenesis (Kawamori et al., 1999)

Anti-inflammatory

With respect to inflammation, in vitro, it inhibits the activation of free radical-activated transcription factors, such as nuclear factor κB (NFκB) and AP-1, and reduces the production of pro-inflammatory cytokines such as tumor necrosis factor-α (TNFα), interleukin-1β (IL-1β), and interleukin-8 (Chan et al., 1998)

Prostate Cancer

In addition, NF-kappaB and AP-1 may play a role in the survival of prostate cancer cells, and curcumin may abrogate their survival mechanisms (Mukhopadhyay et al., 2001).

Pancreatic Cancer

In patients suffering from pancreatic cancer, orally-administered curcumin was found to be well-tolerated and despite limited absorption, had a reasonable impact on biological activity in some patients. This was attributed to its potent nuclear factor-kappaB (NF-kappaB) and tumor-inhibitory properties, against advanced pancreatic cancer (Dhillon et al., 2008)

MDR

Curcumin, the major component in Curcuma longa (Jianghuang), inhibited the transport activity of all three major ABC transporters, i.e. Pgp, MRP1 and ABCG2 (Ganta et al., 2009).

Curcumin reversed MDR of doxorubicin or daunorubicin in K562/DOX cell line and decreased Pgp expression in a time-dependent manner (Chang et al., 2006). Curcumin enhanced the sensitivity to vincristine by the inhibition of Pgp in SGC7901/VCR cell line (Tang et al., 2005). Moreover, curcumin was useful in reversing MDR associated with a decrease in bcl-2 and survivin expression but an increase in caspase-3 expression in COC1/DDP cell line (Ying et al., 2007).

The cytotoxicity of vincristine and paclitaxel were also partially restored by curcumin in resistant KBV20C cell line. Curcumin derivatives reversed MDR by inhibiting Pgp efflux (Um et al., 2008). A chlorine substituent at the meta-or para-position on benzamide improved MDR reversal [72]. Bisdemethoxycurcumin modified from curcumin resulted in greater inhibition of Pgp expression (Limtrakul et al., 2004).

Attenuation of Immune Suppression

Curcumin (a chalcone) exhibited toxicity to human neural stem cells (hNSCs). Although oridonin (a diterpene) showed a null toxicity toward hNSCs, it repressed the enzymatic function only marginally in contrast to its potent cytotoxicity in various cancer cell lines. While the mode of action of the enzyme-polyphenol complex awaits to be investigated, the sensitivity of enzyme inhibition was compared to the anti-proliferative activities toward three cancer cell lines.

The IC50s obtained from both sets of the experiments indicate that they are in the vicinity of micromolar concentration with the enzyme inhibition slightly more active.

These results suggest that attenuation of immune suppression via inhibition of IDO-1 enzyme activity may be one of the important mechanisms of polyphenols in chemoprevention or combinatorial cancer therapy (Chen et al., 2012).

Cancer Stem Cells

In cancers that appear to follow the stem cell model, pathways such as Wnt, Notch and Hedgehog may be targeted with natural compounds such as curcumin or drugs to reduce the risk of initiation of new tumors. Disease progression of established tumors could also potentially be inhibited by targeting the tumorigenic stem cells alone, rather than aiming to reduce overall tumor size.

Cancer treatments could be evaluated by assessing stem cell markers before and after treatment. Targeted stem cell specific treatment of cancers may not result in 'complete' or 'partial' responses radiologically, as stem cell targeting may not reduce the tumor bulk, but eliminate further tumorigenic potential. These changes are discussed using breast, pancreatic, and lung cancer as examples (Reddy et al., 2011).

Multiple Cancer Effects; Cell-signaling

Curcumin has been shown to interfere with multiple cell signaling pathways, including cell-cycle (cyclin D1 and cyclin E), apoptosis (activation of caspases and down-regulation of anti-apoptotic gene products), proliferation (HER-2, EGFR, and AP-1), survival (PI3K/AKT pathway), invasion (MMP-9 and adhesion molecules), angiogenesis (VEGF), metastasis (CXCR-4) and inflammation (NF- κB, TNF, IL-6, IL-1, COX-2, and 5-LOX).

The activity of curcumin reported against leukemia and lymphoma, gastrointestinal cancers, genitourinary cancers, breast cancer, ovarian cancer, head and neck squamous cell carcinoma, lung cancer, melanoma, neurological cancers, and sarcoma reflects its ability to affect multiple targets (Anand et al., 2008).

Anti-inflammatory; Cell-signaling

Curcumin, a liposoluble polyphenolic pigment isolated from the rhizomes of Curcuma longa L. (Zingiberaceae), is another potential candidate for new anti-cancer drug development. Curcumin has been reported to influence many cell-signaling pathways involved in tumor initiation and proliferation. Curcumin inhibits COX-2 activity, cyclin D1 and MMPs overexpresion, NF-kB, STAT and TNF-alpha signaling pathways and regulates the expression of p53 tumor suppressing gene.

Curcumin is well-tolerated but has a reduced systemic bioavailability. Polycurcumins (PCurc 8) and curcumin encapsulated in biodegradable polymeric nanoparticles showed higher bioavailability than curcumin together with a significant tumor growth inhibition in both in vitro and in vivo studies (Cretu et al., 2012). Curcumin also sensitizes tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis through reactive oxygen species-mediated up-regulation of death receptor 5 (DR5) (Jung et al., 2005).

Curcumin and bioavailability

Curcumin, a major constituent of the spice turmeric, suppresses expression of the enzyme cyclooxygenase 2 (Cox-2) and has cancer chemo-preventive properties in rodents. It possesses poor systemic availability. Marczylo et al. (2007) explored whether formulation with phosphatidylcholine increases the oral bioavailability or affects the metabolite profile of curcumin. Their results suggest that curcumin formulated with phosphatidylcholine furnishes higher systemic levels of parent agent than unformulated curcumin.

Curcuminoids are poorly water-soluble compounds and to overcome some of the drawbacks of curcuminoids, Aditya et al. (2012) explored the potential of liposomes for the intravenous delivery of curcuminoids. The curcuminoids-loaded liposomes were formulated from phosphatidylcholine (soy PC). Curcumin/curcuminoids were encapsulated in phosphatidylcholine vesicles with high yields. Vesicles in the size range around 200 nm were selected for stability and cell experiments. Liposomal curcumin were found to be twofold to sixfold more potent than corresponding curcuminoids. Moreover, the mixture of curcuminoids was found to be more potent than pure curcumin in regard to the anti-oxidant and anti-inflammatory activities (Basnet et al., 2012). Results suggest that the curcumin-phosphatidylcholine complex improves the survival rate by increasing the anti-oxidant activity (Inokuma et al., 2012). Recent clinical trials on the effectiveness of phosphatidylcholine formulated curcumin in treating eye diseases have also shown promising results, making curcumin a potent therapeutic drug candidate for inflammatory and degenerative retinal and eye diseases (Wang et al., 2012). Data demonstrate that treatment with curcumin dissolved in sesame oil or phosphatidylcholine curcumin improves the peripheral neuropathy of R98C mice by alleviating endoplasmic reticulum stress, by reducing the activation of unfolded protein response (Patzk- et al., 2012).

References

Aditya NP, Chimote G, Gunalan K, et al. (2012). Curcuminoids-loaded liposomes in combination with arteether protects against Plasmodium berghei infection in mice. Exp Parasitol, 131(3):292-9. doi: 10.1016/j.exppara.2012.04.010.


Anand P, Sundaram C, Jhurani S, Kunnumakkara AB, Aggarwal BB. (2008). Curcumin and cancer: An 'old-age' disease with an 'age-old' solution. Cancer Letters, 267(1):133–164. doi: 10.1016/j.canlet.2008.03.025.


Basnet P, Hussain H, Tho I, Skalko-Basnet N. (2012). Liposomal delivery system enhances anti-inflammatory properties of curcumin. J Pharm Sci, 101(2):598-609. doi: 10.1002/jps.22785.


Chan MY, Huang HI, Fenton MR, Fong D. (1998). In Vivo Inhibition of Nitric Oxide Synthase Gene Expression by Curcumin, a Cancer-preventive Natural Product with Anti-Inflammatory Properties. Biochemical Pharmacology, 55(12), 1955-1962.


Chang HY, Pan KL, Ma FC, et al. (2006). The study on reversing mechanism of Multi-drug resistance of K562/DOX cell line by curcumin and erythromycin. Chin J Hem, 27(4):254-258.


Chen SS, Corteling R, Stevanato L, Sinden J. (2012). Polyphenols Inhibit Indoleamine 3,5-Dioxygenase-1 Enzymatic Activity — A Role of Immunomodulation in Chemoprevention. Discovery Medicine.


Cre ţ u E, Trifan A, Vasincu A, Miron A. (2012). Plant-derived anti-cancer agents – curcumin in cancer prevention and treatment. Rev Med Chir Soc Med Nat Iasi, 116(4):1223-9.


Dhillon N, Aggarwal BB, Newman RA, et al. (2008). Phase II trial of curcumin in patients with advanced pancreatic cancer. Clin Cancer Res,14(14):4491-9. doi: 10.1158/1078-0432.CCR-08-0024.


Ganta S, Amiji M. (2009). Coadministration of paclitaxel and curcumin in nanoemulsion formulations To overcome Multi-drug resistance in tumor cells. Mol Pharm, 6(3):928-939. doi: 10.1021/mp800240j.


Inokuma T, Yamanouchi K, Tomonaga T, et al. (2012). Curcumin improves the survival rate after a massive hepatectomy in rats. Hepatogastroenterology, 59(119):2243-7. doi: 10.5754/hge10650.


Jung EM, Lim JH, Lee TJ, et al. (2005). Curcumin sensitizes tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis through reactive oxygen species-mediated up-regulation of death receptor 5 (DR5). Carcinogenesis, 26(11):1905-1913.


Kawamori T, Lubet R, Steele V E, et al. (1999). Chemo-preventive Effect of Curcumin, a Naturally Occurring Anti-Inflammatory Agent, during the Promotion/Progression Stages of Colon Cancer. Cancer Research, 59(3), 597-601.


Limtrakul P, Anuchapreeda S, Buddhasukh D. (2004). Modulation of human Multi-drug resistance MDR-1 gene by natural curcuminoids. BMC Cancer, 4:13.


Marczylo TH, Verschoyle RD, Cooke DN, et al. (2007). Comparison of systemic availability of curcumin with that of curcumin formulated with phosphatidylcholine. Cancer Chemother Pharmacol, 60(2):171-7.


Mukhopadhyay A, Bueso-Ramos C, Chatterjee D, Pantazis P, & Aggarwal., B. B. (2001). Curcumin downregulates cell survival mechanisms in human prostate cancer cell lines. Oncogene, 20(52), 7597-7609.


Patzk- A, Bai Y, Saporta MA, et al. (2012). Curcumin derivatives promote Schwann cell differentiation and improve neuropathy in R98C CMT1B mice. Brain, 135(Pt 12):3551-66. doi: 10.1093/brain/aws299.


Reddy RM, Kakarala M, Wicha MS. (2011). Clinical trial design for testing the stem cell model for the prevention and treatment of cancer. Cancers (Basel), 3(2):2696-708. doi: 10.3390/cancers3022696.


Tang XQ, Bi H, Feng JQ, Cao JG. (2005). Effect of curcumin on Multi-drug resistance in resistant human gastric carcinoma cell line SGC7901/VCR. Acta Pharmacol Sin, 26(8):1009-1016.


Um Y, Cho S, Woo HB, et al. (2008). Synthesis of curcumin mimics with Multi-drug resistance reversal activities. Bioorg Med Chem,16(7):3608-3615.


Wang LL, Sun Y, Huang K, Zheng L. (2012). Curcumin, a potential therapeutic candidate for retinal diseases. Mol Nutr Food Res, 57(9):1557-68. doi: 10.1002/mnfr.201200718.


Ying HC, Zhang SL, Lv J. (2007). Drug-resistant reversing effect of curcumin on COC1/DDP and its mechanism. J Mod Oncol, 15(5):604-607.