Category Archives: epidermal growth factor receptor

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.

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.

Artesunate

Cancer: Colon, esophageal., pancreatic, ovarian, multiple myeloma and diffuse large B-cell lymphoma, osteosarcoma, lung, breast, skin, leukemia/lymphoma

Action: Anti-metastatic, MDR, radio-sensitizer

Pulmonary Adenocarcinomas

Artesunate exerts anti-proliferative effects in pulmonary adenocarcinomas. It mediates these anti-neoplastic effects by virtue of activating Bak (Zhou et al., 2012). At the same time, it down-regulates epidermal growth factor receptor expression. This results in augmented non-caspase dependent apoptosis in the adenocarcinoma cells. Artesunate mediated apoptosis is time as well as dose-dependent. Interestingly, AIF and Bim play significant roles in this Bak-dependent accentuated apoptosis (Ma et al., 2011). Adenosine triphosphate (ATP)-binding cassette subfamily G member 2 (ABCG2) expression is also attenuated while transcription of matrix metallopeptidase 7 (MMP-7) is also down-regulated (Zhao et al., 2011). In addition, arsenuate enhances the radio-sensitization of lung carcinoma cells. It mediates this effect by down-regulating cyclin B1 expression, resulting in augmented G2/M phase arrest (Rasheed et al., 2010).

Breast Cancer

Similarly, artesunate exhibits anti-neoplastic effects in breast carcinomas. Artesunate administration is typically accompanied by attenuated turnover as well as accentuated peri-nuclear localization of autophagosomes in the breast carcinoma cells. Mitochondrial outer membrane permeability is typically augmented. As a result, artesunate augments programmed cellular decline in breast carcinoma cells (Hamacher-Brady et al., 2011).

Skin Cancer

Artesunate also exerts anti-neoplastic effects in skin malignancies. It mediates these effects by up-regulating p21. At the same time it down-regulates cyclin D1 (Jiang et al., 2012).

Colon Cancer

Artemisunate significantly inhibited both the invasiveness and anchorage independence of colon cancer SW620 cells in a dose-dependent manner. The protein level of intercellular adhesion molecule 1 (ICAM-1) was down-regulated as relative to the control group.

Artemisunate could potentially inhibit invasion of the colon carcinoma cell line SW620 by down-regulating ICAM-1 expression (Fan, Zhang, Yao & Li, 2008).

Multi-drug resistance; Colon Cancer

A profound cytotoxic action of the antimalarial., artesunate (ART), was identified against 55 cancer cell lines of the U.S. National Cancer Institute (NCI). The 50% inhibition concentrations (IC50 values) for ART correlated significantly to the cell doubling times (P = 0.00132) and the portion of cells in the G0/G1 (P = 0.02244) or S cell-cycle phases (P = 0.03567).

Efferth et al., (2003) selected mRNA expression data of 465 genes obtained by microarray hybridization from the NCI data-base. These genes belong to different biological categories (drug resistance genes, DNA damage response and repair genes, oncogenes and tumor suppressor genes, apoptosis-regulating genes, proliferation-associated genes, and cytokines and cytokine-associated genes). The constitutive expression of 54 of 465 (=12%) genes correlated significantly to the IC50 values for ART. Hierarchical cluster analysis of these 12 genes allowed the differentiation of clusters with ART-sensitive or ART-resistant cell lines (P = 0.00017).

Multi-drug-resistant cells differentially expressing the MDR1, MRP1, or BCRP genes were not cross-resistant to ART. ART acts via p53-dependent and- independent pathways in isogenic p53+/+ p21WAF1/CIP1+/+, p53-/- p21WAF1/CIP1+/+, and p53+/+ p21WAF1/CIP1-/- colon carcinoma cells.

Multi-drug resistance; Esophageal Cancer

The present study aimed to investigate the correlation between ABCG2 expression and the MDR of esophageal cancer and to estimate the therapeutic benefit of down-regulating ABCG2 expression and reversing chemoresistance in esophageal cells using artesunate (ART).

ART is a noteworthy antimalarial agent, particularly in severe and drug-resistant cancer cases, as ART is able to reverse drug resistance. ART exerted profound anti-cancer activity. The mechanism for the reversal of multi-drug resistance by ART in esophageal carcinoma was analyzed using cellular experiments, but still remains largely unknown (Liu, Zuo, & Guo, 2013).

Pancreatic Cancer

The combination of triptolide and artesunate could inhibit pancreatic cancer cell line growth, and induce apoptosis, accompanied by expression of HSP 20 and HSP 27, indicating important roles in the synergic effects. Moreover, tumor growth was decreased with triptolide and artesunate synergy. Results indicated that triptolide and artesunate in combination at low concentrations can exert synergistic anti-tumor effects in pancreatic cancer cells with potential clinical applications (Liu & Cui, 2013).

Ovarian Cancer

Advanced-stage ovarian cancer (OVCA) has a unifocal origin in the pelvis. Molecular pathways associated with extrapelvic OVCA spread are also associated with metastasis from other human cancers and with overall patient survival. Such pathways represent appealing therapeutic targets for patients with metastatic disease.

Pelvic and extrapelvic OVCA implants demonstrated similar patterns of signaling pathway expression and identical p53 mutations.

However, Marchion et al. (2013) identified 3 molecular pathways/cellular processes that were differentially expressed between pelvic and extrapelvic OVCA samples and between primary/early-stage and metastatic/advanced or recurrent ovarian, oral., and prostate cancers. Furthermore, their expression was associated with overall survival from ovarian cancer (P = .006), colon cancer (1 pathway at P = .005), and leukemia (P = .05). Artesunate-induced TGF-WNT pathway inhibition impaired OVCA cell migration.

Multiple Myeloma, B-cell Lymphoma

Findings indicate that artesunate is a potential drug for treatment of multiple myeloma and diffuse large B-cell lymphoma (DLBCL) at doses of the same order as currently in use for treatment of malaria without serious adverse effects. Artesunate treatment efficiently inhibited cell growth and induced apoptosis in cell lines. Apoptosis was induced concomitantly with down-regulation of MYC and anti-apoptotic Bcl-2 family proteins, as well as with cleavage of caspase-3. The IC50 values of artesunate in cell lines varied between 0.3 and 16.6 µm. Furthermore, some primary myeloma cells were also sensitive to artesunate at doses around 10 µm. Concentrations of this order are pharmacologically relevant as they can be obtained in plasma after intravenous administration of artesunate for malaria treatment (Holien et al., 2013).

Osteosarcoma, Leukemia/Lymphoma

Artesunate inhibits growth and induces apoptosis in human osteosarcoma HOS cell line in vitro and in vivo (Xu et al. 2011). ART alone or combined with chemotherapy drugs could inhibit the proliferation of B/T lymphocytic tumor cell lines as well ALL primary cells in vitro, probably through the mechanism of apoptosis, which suggest that ART is likely to be a potential drug in the treatment of leukemia/lymphoma (Zeng et al., 2009).

References

Efferth, T., Sauerbrey, A., Olbrich, A., et al. (2003) Molecular modes of action of artesunate in tumor cell lines. Mol Pharmacol, 64(2):382-94.


Fan, Y., Zhang, Y.L., Yao, G.T., & Li, Y.K. (2008). Inhibition of Artemisunate on the invasion of human colon cancer line SW620. Lishizzhen Medicine and Materia Medica Research, 19(7), 1740-1741.


Hamacher-Brady, A., Stein, H.A., Turschner, S., et al. (2011). Artesunate activates mitochondrial apoptosis in breast cancer cells via iron-catalyzed lysosomal reactive oxygen species production. J Biol Chem. 2011;286(8):6587–6601. doi: 10.1074/jbc.M110.210047.


Holien, T., Olsen, O.E., Misund, K., et al. (2013). Lymphoma and myeloma cells are highly sensitive to growth arrest and apoptosis induced by artesunate. Eur J Haematol, 91(4):339-46. doi: 10.1111/ejh.12176.


Jiang, Z., Chai, J., Chuang, H.H., et al. (2012). Artesunate induces G0/G1 cell-cycle arrest and iron-mediated mitochondrial apoptosis in A431 human epidermoid carcinoma cells. Anti-cancer Drugs, 23(6):606–613. doi: 10.1097/CAD.0b013e328350e8ac.


Liu, L., Zuo, L.F., Guo, J.W. (2013). Reversal of Multi-drug resistance by the anti-malaria drug artesunate in the esophageal cancer Eca109/ABCG2 cell line. Oncol Lett, 6(5):1475-1481.


Liu, Y. & Cui, Y.F. (2013). Synergism of cytotoxicity effects of triptolide and artesunate combination treatment in pancreatic cancer cell lines. Asian Pac J Cancer Prev, 14(9):5243-8.


Ma, H., Yaom Q., Zhang, A.M., et al. (2011). The effects of artesunate on the expression of EGFR and ABCG2 in A549 human lung cancer cells and a xenograft model. Molecules, 16(12):10556–10569. doi: 10.3390/molecules161210556.


Marchion, D.C., Xiong, Y., Chon, H.S., et al. (2013). Gene expression data reveal common pathways that characterize the unifocal nature of ovarian cancer. Am J Obstet Gynecol, S0002-9378(13)00827-2. doi: 10.1016/j.ajog.2013.08.004.


Rasheed, S.A., Efferth, T., Asangani, I.A., Allgayer, H. (2010). First evidence that the antimalarial drug artesunate inhibits invasion and in vivo metastasis in lung cancer by targeting essential extracellular proteases. Int J Cancer, 127(6):1475–1485. doi: 10.1002/ijc.25315.


Xu, Q., Li, Z.X., Peng, H.Q., et al. (2011). Artesunate inhibits growth and induces apoptosis in human osteosarcoma HOS cell line in vitro and in vivo. J Zhejiang Univ-Sci B (Biomed & Biotechnol), 12(4):247–255. doi: 10.1631/jzus.B1000373.


Zhao, Y., Jiang, W., Li, B., et al. (2011). Artesunate enhances radiosensitivity of human non-small-cell lung cancer A549 cells via increasing no production to induce cell-cycle arrest at G2/M phase. Int Immunopharmacol, 11(12):2039–2046. doi: 10.1016/j.intimp.2011.08.017.


Zeng, Y., Ni, X., Meng, W.T., Wen, Q., Jia, Y.Q. (2009). Inhibitive effect of artesunate on human lymphoblastic leukemia/lymphoma cells. Sichuan Da Xue Xue Bao Yi Xue Ban, 40(6):1038-43.


Zhou, C., Pan, W., Wang, X.P., Chen, T.S. (2012). Artesunate induces apoptosis via a bak-mediated caspase-independent intrinsic pathway in human lung adenocarcinoma cells. J Cell Physiol, 227(12):3778–3786. doi: 10.1002/jcp.24086.

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.

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Emodin (See also Aloe-Emodin)

Cancer:
Breast, colon, liver, chemotherapy, myeloma, oral., pancreatic, hepatocellular carcinoma, lung, leukemia

Action: MDR-1, cell-cycle arrest

Emodin is an active natural anthraquinone derivative component of a traditional Chinese and Japanese medicine isolated from the root and rhizomes of Rheum palmatum L., Senna obtusifolia [(L.) H.S.Irwin & Barneby], Fallopia japonica [Houtt. (Ronse Decr.)], Kalimeris indica (L.) Sch.Bip., Ventilago madraspatana (Gaertn.), Rumex nepalensis (Spreng.), Fallopia multiflora [(Thunb.) Haraldson], Cassia occidentalis [(L.) Link], Senna siamea [(Lam.) Irwin et Barneby] and Acalypha australis (L.).

Aloe-emodin is an active natural anthraquinone derivative, and is found in the roots and rhizomes of numerous Chinese medicinal herbs (including Rheum palmatum L) and exhibits anti-cancer effects on many types of human cancer cell lines.

Administration of rhubarb (Emodin) can effectively reverse severe acute pancreatitis (SAP) by regulating the levels of IL-15 and IL-18 (Yu & Yang, 2013).

Pancreatic Cancer

Emodin is a tyrosine kinase inhibitor that has an inhibitory effect on mammalian cell-cycle modulation in specific oncogene-overexpressing cells. Recently, there has been great progress in the preclinical study of the anti-cancer mechanisms of emodin. A recent study revealed that emodin has therapeutic effects on pancreatic cancer through various anti-tumor mechanisms. Notably, the therapeutic efficacy of emodin in combination with chemotherapy was found to be higher than the comparable single chemotherapeutic regime, and the combination therapy also exhibited fewer side-effects (Wei et al., 2013).

Hepatocellular Carcinoma, Pancreatic, Breast, Colorectal and Lung Cancers, and Leukemia

Emodin is found as an active ingredient in different Chinese herbs including Rheum palmatum and Polygonam multiflorum, and has diuretic, vasorelaxant, anti-bacterial., anti-viral., anti-ulcerogenic, anti-inflammatory, and anti-cancer effects. The anti-inflammatory effects of emodin have been exhibited in various in vitro as well as in vivo models of inflammation including pancreatitis, arthritis, asthma, atherosclerosis and glomerulonephritis. As an anti-cancer agent, emodin has been shown to suppress the growth of various tumor cell lines including hepatocellular carcinoma, pancreatic, breast, colorectal., leukemia, and lung cancers. Emodin is a pleiotropic molecule capable of interacting with several major molecular targets including NF-κB, casein kinase II, HER2/neu, HIF-1α, AKT/mTOR, STAT3, CXCR4, topoisomerase II, p53, p21, and androgen receptors which are involved in inflammation and cancer (Shrimali et al., 2013).

Hepatocellular Carcinoma

It has been found that emodin induces apoptotic responses in the human hepatocellular carcinoma cell lines (HCC) Mahlavu, PLC/PRF/5 and HepG2. The addition of emodin to these three cell lines led to inhibition of growth in a time-and dose-dependent manner. Emodin generated reactive oxygen species (ROS) in these cells which brought about a reduction of the intracellular mitochondrial transmembrane potential (ΔΨ m), followed by the activation of caspase–9 and caspase–3, leading to DNA fragmentation and apoptosis.

Preincubation of hepatoma cell lines with the hydrogen peroxide-scavenging enzyme, catalase (CAT) and cyclosporin A (CsA), partially inhibited apoptosis. These results demonstrate that enhancement of generation of ROS, DeltaPsim disruption and caspase activation may be involved in the apoptotic pathway induced by emodin (Jing et al., 2002).

Colon Cancer

In in vitro study, emodin induced cell morphological changes, decreased the percentage of viability, induced G2/M phase arrest and increased ROS and Ca(2+) productions as well as loss of mitochondrial membrane potential (ΔΨ(m)) in LS1034 cells. Emodin-triggered apoptosis was also confirmed by DAPI staining and these effects are concentration-dependent.

In in vivo study, emodin effectively suppressed tumor growth in tumor nude mice xenografts bearing LS1034. Overall, the potent in vitro and in vivo anti-tumor activities of emodin suggest that it might be developed for treatment of colon cancer in the future (Ma et al., 2012).

Myeloid Leukemia

It has been shown that emodin significantly induces cytotoxicity in the human myeloma cells through the elimination of myeloid cell leukemia 1 (Mcl-1). Emodin inhibited interleukin-6–induced activation of Janus-activated kinase 2 (JAK2) and phosphorylation of signal transducer and activator of transcription 3 (STAT3), followed by the decreased expression of Mcl-1. Activation of caspase-3 and caspase-9 was triggered by emodin, but the expression of other anti-apoptotic Bcl-2 family members, except Mcl-1, did not change in the presence of emodin. To clarify the importance of Mcl-1 in emodin-induced apoptosis, the Mcl-1 expression vector was introduced into the human myeloma cells by electroporation. Induction of apoptosis by emodin was almost abrogated in Mcl-1–overexpressing myeloma cells as the same level as in parental cells, which were not treated with emodin. Emodin therefore inhibits interleukin-6–induced JAK2/STAT3 pathway selectively and induces apoptosis in myeloma cells via down-regulation of Mcl-1, which is a good target for treating myeloma. Taken together, these results show emodin as a new potent anti-cancer agent for the treatment of multiple myeloma patients (Muto et al., 2007).

Breast Cancer; Block HER-2

The mechanism by which emodin prevents breast cancer is unknown; however the product of the HER-2/neu proto-oncogene, HER2 has been proposed to be involved. The product of the HER-2/neu proto-oncogene, HER2, is the second member of the human epidermal growth factor receptor (HER) family of tyrosine kinase receptors and has been suggested to be a ligand orphan receptor. Amplification of the HER2 gene and overexpression of the HER2 protein induces cell transformation and has been demonstrated in 10% to 40% of human breast cancer. HER2 overexpression has been suggested to associate with tumor aggressiveness, prognosis and responsiveness to hormonal and cytotoxic agents in breast cancer patients. These findings indicate that HER2 is an appropriate target for tumor-specific therapies.

A number of approaches have been investigated: (1) a humanized monoclonal antibody against HER2, rhuMAbHER2 (trastuzumab), which is already approved for clinical use in the treatment of patients with metastatic breast cancer; (2) tyrosine kinase inhibitors, such as emodin, which block HER2 phosphorylation and its intracellullar signaling; (3) active immunotherapy, such as vaccination; and (4) heat shock protein (Hsp) 90-associated signal inhibitors, such as radicicol derivatives, which induce degradation of tyrosine kinase receptors, such as HER2 (Kurebayashi, 2001).

MDR

The effects of emodin on the nucleoside transport and multi-drug resistance in cancer cells has also been investigated. Nucleoside transport inhibition was determined by thymidine incorporation assay. The cytotoxicity to cancer cells was determined by MTT assay. The pump efflux activity and the expression of P glycoprotein were examined by flow cytometric assay. Emodin was active in the inhibition of nucleoside transport, with an IC 50 value of 9 9 µmol·L -1. Emodin markedly enhanced the cytotoxicity of 5 FU, MMC and MTX against human hepatoma BEL 7402 cells and partly reversed the multi-drug resistance in human breast cancer MCF 7/Adr cells.

Emodin inhibited P-gp pump efflux activity and reduced the expression of P gp in MCF 7/Adr cells. These findings provide a biological basis for the application of emodin as a biochemical modulator to potentiate the effects of anti-tumor drugs and reverse the multi-drug resistance in cancer cells (Jiang et al., 2009).

Cell-cycle Arrest

Large quantities of emodin were isolated from the roots of Rheum emodi and a library of novel emodin derivatives 2–15 were prepared to evaluate their anti-proliferative activities against HepG2, MDA-MB-231 and NIH/3T3 cells lines. The derivatives 3 and 12 strongly inhibited the proliferation of HepG2 and MDA-MB-231 cancer cell line with an IC50 of 5.6, 13.03 and 10.44, 5.027, respectively, which is comparable to marketed drug epirubicin (III). The compounds 3 and 12 were also capable of inducing cell-cycle arrest and caspase dependent apoptosis in HepG2 cell lines and exhibit DNA intercalating activity. These emodin derivatives hold promise for developing safer alternatives to the marketed epirubicin (Narender et al., 2013).

Cell-cycle Arrest; MDR1 & AZT

3'-azido-3'-deoxythymidine (AZT) and emodin altered the cell-cycle distribution and led to an accumulation of cells in S phase. Meanwhile, the expression of MDR1 mRNA/p-gp protein was markedly decreased. These results show a synergistic growth-inhibitory effect of AZT and emodin in K562/ADM cells, which is achieved through S phase arrest. MDR1 might ultimately be responsible for these phenomena (Chen et al., 2013).

References

Chen P, Liu Y, Sun Y, et al. (2013). AZT and emodin exhibit synergistic growth-inhibitory effects on K562/ADM cells by inducing S phase cell-cycle arrest and suppressing MDR1 mRNA/p-gp protein expression. Pharm Biol.


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Muto A, Hori M, Sasaki Y, et al. (2007). Emodin has a cytotoxic activity against human multiple myeloma as a Janus-activated kinase 2 inhibitor. Mol Cancer Ther. doi: 10.1158/1535-7163.MCT-06-0605.


Narender T, Sukanya P, Sharma K, et al. (2013). Preparation of novel anti-proliferative emodin derivatives and studies on their cell-cycle arrest, caspase dependent apoptosis and DNA binding interaction. Phytomedicine, 20(10):890-896.


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