Xu Hong-Bin, Fu Jun, Huang Fang, Yu Jing
Department of Pharmacy, Shanghai Tenth People's Hospital, Tongji University School of Medicine, 200072 Shanghai, China.
Department of Pharmacy, Shanghai Tenth People's Hospital, Tongji University School of Medicine, 200072 Shanghai, China.
Eur J Pharmacol. 2017 May 15;803:57-64. doi: 10.1016/j.ejphar.2017.03.045. Epub 2017 Mar 23.
Previous researches indicated that cyclooxygenase-2 (Cox-2) might be involved in P-glycoprotein (P-gp)-mediated multidrug resistance in hepatocellular carcinoma cells. Doxorubicin-resistant hepatocellular carcinoma PLC/PRF/5 cells (PLC/PRF/5R) and HepG2 (HepG2R) cells were developed in the present study. The modulatory effect of guggulsterone on Cox-2 and P-gp in PLC/PRF/5R and HepG2R cells was investigated. Cells proliferation, Cox-2 and P-gp expression, and prostaglandin E release were examined using MTT, flow cytometry, western blot and ELISA assays. Small interfering RNA (siRNA) targeted against Cox-2 and multidrug resistance protein (Mdr-1) was used to regulate the expression of Cox-2 and P-gp. The results showed that co-administration of guggulsterone resulted in a significant increase in chemo-sensitivity of PLC/PRF/5R cells to doxorubicin, as compared with doxorubicin treatment alone. When doxorubicin (10µM) was combined with guggulsterone (50µM), the mean apoptotic population of PLC/PRF/5R cells was 20.16%. It was increased by 1.5 times, as compared with doxorubicin (10µM) treatment alone. Furthermore, guggulsterone had significantly inhibitory effect on the levels of Cox-2, P-gp and prostaglandin E. However, guggulsterone did not show significantly inhibitory effect on the expression of prostaglandin E receptors. In addition, Cox-2 siRNA simultaneously reduced the expression of Cox-2 and P-gp in PLC/PRF/5R cells. Mdr-1 siRNA had no influence on Cox-2, but inhibited P-gp expression. The present study suggested that guggulsterone might enhance the cytotoxic effect of doxorubicin to PLC/PRF/5R cells through a Cox-2/P-gp dependent pathway.
先前的研究表明，环氧化酶-2（Cox-2）可能参与了肝细胞癌细胞中P-糖蛋白（P-gp）介导的多药耐药。本研究构建了阿霉素耐药的肝癌PLC/PRF/5细胞（PLC/PRF/5R）和HepG2（HepG2R）细胞。研究了古古甾酮对PLC/PRF/5R和HepG2R细胞中Cox-2和P-gp的调节作用。采用MTT、流式细胞术、蛋白质免疫印迹和酶联免疫吸附测定法检测细胞增殖、Cox-2和P-gp表达以及前列腺素E释放。针对Cox-2和多药耐药蛋白（Mdr-1）的小干扰RNA（siRNA）用于调节Cox-2和P-gp的表达。结果表明，与单独使用阿霉素治疗相比，联合使用古古甾酮可显著提高PLC/PRF/5R细胞对阿霉素的化疗敏感性。当阿霉素（10µM）与古古甾酮（50µM）联合使用时，PLC/PRF/5R细胞的平均凋亡率为20.16%。与单独使用阿霉素（10µM）治疗相比，增加了1.5倍。此外，古古甾酮对Cox-2、P-gp和前列腺素E水平具有显著抑制作用。然而，古古甾酮对前列腺素E受体的表达未显示出显著抑制作用。此外，Cox-2 siRNA同时降低了PLC/PRF/5R细胞中Cox-2和P-gp的表达。Mdr-1 siRNA对Cox-2无影响，但抑制P-gp表达。本研究表明，古古甾酮可能通过Cox-2/P-gp依赖途径增强阿霉素对PLC/PRF/5R细胞的细胞毒性作用。
