选择性环氧化酶-2抑制剂NS-398抗结肠癌机制及对5-氟尿嘧啶化疗的辅助作用

目的 研究选择性环氧化酶-2(COX-2)抑制剂NS-398的抗结肠癌作用机制及其在5-氟尿嘧啶(5-Fu)化疗中的辅助作用。方法 (1)用逆转录-聚合酶链反应(RT—PCR)检测结肠癌HT-29、SW480细胞COX-2 mRNA表达后,将NS-398作用于两株细胞,用ELISA法测定前列腺素E2(PGE2)水平。(2)将NS-398、5-Fu、NS-398 5-Fu分别作用于两株细胞,24、48和72h后用MTT法检测细胞增殖状态。以流式细胞技术观察药物对细胞凋亡的影响。结果 (1)HT-29细胞中COX-2 mRNA呈高表达,NS-398作用后PGE2表达水平明显降低;SW480细胞中COX-2 mRNA表达呈阴性,NS-398作用后PGE2水平无明显变化。(2)NS-398、5-Fu呈剂量依赖性方式抑制结肠癌细胞增殖,诱导其凋亡;NS-398 5-Fu抗增殖的作用较单一用药时更明显,而凋亡诱导作用与单一用药差异无显著意义。结论 选择性COX-2抑制剂NS-398具有抗结肠癌作用;NS-398抗结肠癌作用可能不依赖于COX-2和PGE2的表达水平;NS-398与5-Fu具有协同的抗增殖作用。

Effects of selective cyclooxygenase-2 inhibitor NS-398 on 5-fluorouracil chemotherapy and progression of colon cells: an experimental study

Objective To investigate the effects of selective cyclooxygenase-2 (COX-2) inhibitor NS-398 on 5-fluorouracil (5-Fu) chemotherapy and on the progression of colon cells. Methods Colon cancer cells of HT-29 and SW480 lines were cultured. Selective COX-2 inhibitor NS-398, 5-Fu, or NS-398 combining with 5-Fu were added into the cultures to be co-cultured for 24,48, and 72 hours respectively. RT-PCR and ELISA analysis were performed to detect the level of COX-2 mRNA expression and prostaglandin 2 (PGE2) concentration in the cells of both HT-29 and SW480 lines. The proliferation and apoptosis of the two cell lines were observed with MTT assay and flow cytometry. Results Expression of COX-2 mRNA were negative in SW480 line and positive in HT-29 line. Compared with SW480 line, the HT-29 line showed an obvious decline of PGE2 concentration following NS-398 treatment. Both NS-398 and 5-Fu inhibited the cells' proliferation and induced apoptosis in a dose-dependent manner, and a more significant inhibition was found when the cells were co-treated with NS-398 and 5-Fu. Althongh, there was no significant difference between these in inducing apoptosis. Conclusion Selective COX-2 inhibitor NS-398 can inhibit the proliferation of colon cancer cells and induce apoptosis thereof. The mechanism of NS-398 against colon cancer may be independent upon the expression levels of COX-2 mRNA and PGE2 of colon cancer. NS-398 may be a subsidiary drug in 5-Fu chemotherapy in treating colon cancer.