First evidence that γ-tocotrienol inhibits the growth of human gastric cancer and chemosensitizes it to capecitabine in a xenograft mouse model through the modulation of NF-κB pathway
MetadataShow full item record
Purpose: Because of poor prognosis and development of resistance against chemotherapeutic drugs, the existing treatment modalities for gastric cancer are ineffective. Hence, novel agents that are safe and effective are urgently needed. Whether γ-tocotrienol can sensitize gastric cancer to capecitabine in vitro and in a xenograft mouse model was investigated. Experimental Design: The effect of γ-tocotrienol on proliferation of gastric cancer cell lines was examined by mitochondrial dye uptake assay, apoptosis by esterase staining, NF-κB activation by DNA-binding assay, and gene expression by Western blotting. The effect of γ-tocotrienol on the growth and chemosensitization was also examined in subcutaneously implanted tumors in nude mice. Results: γ-Tocotrienol inhibited the proliferation of various gastric cancer cell lines, potentiated the apoptotic effects of capecitabine, inhibited the constitutive activation of NF-κB, and suppressed the NF-κB–regulated expression of COX-2, cyclin D1, Bcl-2, CXCR4, VEGF, and matrix metalloproteinase-9 (MMP-9). In a xenograft model of human gastric cancer in nude mice, we found that administration of γ-tocotrienol alone (1 mg/kg body weight, intraperitoneally 3 times/wk) significantly suppressed the growth of the tumor and this effect was further enhanced by capecitabine. Both the markers of proliferation index Ki-67 and for microvessel density CD31 were downregulated in tumor tissue by the combination of capecitabine and γ-tocotrienol. As compared with vehicle control, γ-tocotrienol also suppressed the NF-κB activation and the expression of cyclin D1, COX-2, intercellular adhesion molecule-1 (ICAM-1), MMP-9, survivin, Bcl-xL, and XIAP. Conclusions: Overall our results show that γ-tocotrienol can potentiate the effects of capecitabine through suppression of NF-κB–regulated markers of proliferation, invasion, angiogenesis, and metastasis.
Showing items related by title, author, creator and subject.
Simvastatin sensitizes human gastric cancer xenograft in nude mice to capecitabine by suppressing nuclear factor-kappa B-regulated gene productsManu, K.; Shanmugam, M.; Li, F.; Chen, L.; Siveen, K.; Ahn, K.; Kumar, Alan Prem; Sethi, G. (2013)Chemoresistance remains a major problem in the treatment of gastric cancer patients. Hence, novel pharmacological agents that can overcome drug resistance are urgently required. Whether simvastatin can sensitize the gastric ...
γ-Tocotrienol is a novel inhibitor of constitutive and inducible STAT3 signalling pathway in human hepatocellular carcinoma: Potential role as an antiproliferative, pro-apoptotic and chemosensitizing agentRajendran, P.; Li, F.; Manu, K.; Shanmugam, M.; Loo, S.; Kumar, Alan Prem; Sethi, G. (2011)BACKGROUND AND PURPOSE Activation of signal transducer and activator of transcription 3 (STAT3) play a critical role in the survival, proliferation, angiogenesis and chemoresistance of tumour cells. Thus, agents that ...
Ursolic acid inhibits multiple cell survival pathways leading to suppression of growth of prostate cancer xenograft in nude miceShanmugam, M.; Rajendran, P.; Li, F.; Nema, T.; Vali, S.; Abbasi, T.; Kapoor, S.; Sharma, A.; Kumar, Alan Prem; Ho, P.; Hui, K.; Sethi, G. (2011)Activation of transcription factors nuclear factor-κB (NF-κB) and signal transducer and activator of transcription 3 (STAT3) is frequently observed in prostate cancer and has been linked with tumor cell proliferation, ...