Hui Jia1, Qian Yang2, Tao Wang3, Yu Cao4, Qi-Yu Jiang5, Hong-da Ma1, Hui-Wei Sun2, Ming-Xiao Hou6, Yong-Ping Yang7, Fan Feng8. 1. Department of Pharmacy, General Hospital of Shenyang Military Area Command, Shenyang 110016, PR China. 2. Center of Therapeutic Research for Liver Cancer, The 302nd Hospital, Beijing 100039, PR China. 3. Institute of Toxicology and Pharmacology, Chinese Academy of Military Medical Sciences, Beijing 100850, PR China. 4. Department of Neurology, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912, USA. 5. Research and Technology Service Center, The 302nd Hospital, Beijing 100039, PR China. 6. Department of Pharmacy, General Hospital of Shenyang Military Area Command, Shenyang 110016, PR China. Electronic address: houmingxiao188@126.com. 7. Center of Therapeutic Research for Liver Cancer, The 302nd Hospital, Beijing 100039, PR China. Electronic address: yongpingyang@hotmail.com. 8. Department of Pharmacy, General Hospital of Shenyang Military Area Command, Shenyang 110016, PR China. Electronic address: fengfanbio@126.com.
Abstract
BACKGROUND: The rapid development of multi-drug resistance (MDR) process has hindered the effectiveness of advanced hepatocellular carcinoma (HCC) treatments. Notch-1 pathway, which mediates the stress-response, promotes cell survival, EMT (epithelial-mesenchymal transition) process and induces anti-apoptosis in cancer cells, would be a potential target for overcoming MDR process. This study investigated the potential application of rhamnetin, a specific inhibitor of Notch-1 pathway, in anti-tumor drug sensitization of HCC treatment. METHODS: The expression of miR-34a, proteins belonging to Notch-1 signaling pathway or MDR-related proteins was detected by quantitative polymerase chain reaction (qPCR) and western blot assay. To identify whether rhamnetin induces the chemotherapeutic sensitization in HCC cells, the MTT-assays, flow cytometry, soft agar, trans-well and nude mice assays were performed. RESULTS: The endogenous expression of miR-34a was significantly increased and the expression of Notch-1 and Survivin was downregulated after rhamnetin treatment. Treatment of rhamnetin also reduced the expression of MDR related proteins P-GP (P-glycoprotein) and BCRP (breast cancer resistance protein). Rhamnetin increased the susceptibility of HCC cells and especially HepG2/ADR, a MDR HCC cell line, to a small molecular kinase inhibitor sorafenib or chemotherapeutic drugs etoposide and paclitaxel. The IC(50) value of those drugs correspondingly decreased. CONCLUSIONS: Together, our findings suggest that rhamnetin treatment may attenuate the MDR process in HCC cells. These findings may contribute to more effective strategies for HCC therapy. GENERAL SIGNIFICANCE: Rhamnetin acts as a promising sensitizer to chemotherapy and may be a novel approach to overcome the MDR process of HCC.
BACKGROUND: The rapid development of multi-drug resistance (MDR) process has hindered the effectiveness of advanced hepatocellular carcinoma (HCC) treatments. Notch-1 pathway, which mediates the stress-response, promotes cell survival, EMT (epithelial-mesenchymal transition) process and induces anti-apoptosis in cancer cells, would be a potential target for overcoming MDR process. This study investigated the potential application of rhamnetin, a specific inhibitor of Notch-1 pathway, in anti-tumor drug sensitization of HCC treatment. METHODS: The expression of miR-34a, proteins belonging to Notch-1 signaling pathway or MDR-related proteins was detected by quantitative polymerase chain reaction (qPCR) and western blot assay. To identify whether rhamnetin induces the chemotherapeutic sensitization in HCC cells, the MTT-assays, flow cytometry, soft agar, trans-well and nude mice assays were performed. RESULTS: The endogenous expression of miR-34a was significantly increased and the expression of Notch-1 and Survivin was downregulated after rhamnetin treatment. Treatment of rhamnetin also reduced the expression of MDR related proteins P-GP (P-glycoprotein) and BCRP (breast cancer resistance protein). Rhamnetin increased the susceptibility of HCC cells and especially HepG2/ADR, a MDR HCC cell line, to a small molecular kinase inhibitor sorafenib or chemotherapeutic drugs etoposide and paclitaxel. The IC(50) value of those drugs correspondingly decreased. CONCLUSIONS: Together, our findings suggest that rhamnetin treatment may attenuate the MDR process in HCC cells. These findings may contribute to more effective strategies for HCC therapy. GENERAL SIGNIFICANCE: Rhamnetin acts as a promising sensitizer to chemotherapy and may be a novel approach to overcome the MDR process of HCC.