伊立替康与4-氨基吡啶联合应用对人结直肠癌细胞增殖作用的影响

The effects of irinotecan combined with 4-amion pyridine on the proliferation of human colorectal cancer cell

目的研究肿瘤化学治疗药物伊立替康（CPT-11）对人结直肠癌细胞株HT-29细胞的作用及对钾离子通道阻断剂4-氨基吡啶（4-AP）的影响，并探讨其抗HT-29细胞的可能机制。方法CPT-11、4-AP以及两药联合应用对HT-29细胞增殖及细胞侵袭力的影响分别用MTT比色法和Transwell法检测。用流式细胞术膜联蛋白V-异硫氰酸荧光素碘化丙啶双染法检测上述两种药物对HT29细胞凋亡的影响。用膜片钳方法检测ATP敏感性钾电流（IKATP）的电流变化。结果1．0～64．0μg／ml CPT-11可呈剂量依赖性和时间依赖性地抑制HT-29细胞增殖，而1．0mmol／L的4-AP可使CPT-11的作用增强。16．0μg／mlCPT-11和1．0mmol／L4-AP单独应用均可明显诱导HT-29凋亡、抑制HT29细胞侵袭力，而两药联合应用能明显增加上述诱导凋亡和抑制侵袭力的作用。不同浓度CPT-11可剂量依赖性地降低细胞膜IKATP水平，呈剂量依赖负相关性。结论CPT-11抑制人结直肠癌HT-29细胞增殖和侵袭力、诱导细胞凋亡等作用可被4-AP协同增强，可能机制与CPT-11抑制ATP敏感性钾通道开放有关。

Objective To investigate the effects and potential mechanism of irinotecan （CPT 11）, an antitumor drug, colorectal cancer cell line HT-29 and its impact on 4-amion pyridine （4-AP）, a kalium ion channel blocker. Methods The effects of CPT-11, 4-AP and combination of two drugs on proliferation and invasion of HT 29 cells were measured by MTT and Transwell assay respectively. The impact of CPT-11 or 4 AP on cell apoptosis was determined by flow cytometry with Annexin V and PI staining. The current of ATP sensitive potassium ion （IKATP） was measured by patch clamp. Results The CPT-11 could inhibit proliferation of HT-29 ceils at dose from 1. 0 to 64.0μg/ml in dose- and time dependent manners. Whereas the above effect was enhanced when CPT- 11 combined with 4 AP （1. 0 mmol/L）. The administration of CPT-11 （16. 0 vg/ml） or 4 AP （1.0 mmol/L） significantly induced the cell apoptosis and inhibited the invasion of HT-29 cells, furthermore, these effects could be enhanced by combination of two drugs. And the different concentrations of CPTll reduced the IKATP Of cell membrane in negative dose dependent manner. Conclusions The effects of CPT-11 on HT-29 cells, such as reducing proliferation and invasion as well as inducing the apoptosis, can be enhanced by 4-AP, which may be related to inhibition of ATP- sensitive potassium channels.