5-氮-2′-脱氧胞苷对结肠癌细胞生物学行为的影响

Effects of 5-aza-2'-deoxycytidine on biological behavior of colon tumor cell lines

目的检测去甲基化药物5-氮-2′-脱氧胞苷(5-aza-2′-deoxycytidine,5-aza-dC)对结肠癌细胞株SW620、COLO205和HT29生物学行为的影响,并研究该药物对多个基因表达的影响。方法5-aza-dC处理对各结肠癌细胞生长周期、凋亡、细胞迁移和侵袭能力的影响分别采用流式细胞术、Annexin V/Propidium Iodide法、细胞划痕实验和Transwell小室侵袭实验检测。采用RT-PCR法检测抑癌基因THBS1、TIMP3、RASSF1A和癌基因c-myc、c-fos、bax在5-aza-dC处理前后各结肠癌细胞株中的表达改变情况。结果5-aza-dC处理后,3株结肠癌细胞的生长周期均明显阻滞于G2/M期,细胞凋亡率显著增加(P<0.05)。划痕实验后72h,对照组结肠癌细胞明显向划痕的中央迁移,而药物处理组结肠癌细胞迁移不明显。5-aza-dC处理后,结肠癌细胞的侵袭能力较未处理组降低(P<0.05)。5-aza-dC可恢复结肠癌细胞中多个抑癌基因的表达,但是对癌基因的表达没有影响。结论5-aza-dC对结肠癌细胞有阻滞细胞生长周期、促进凋亡及抑制细胞迁移和侵袭能力等作用,该作用可能是通过恢复多个抑癌基因的表达来实现的。

Purpose To investigate the effects of 5-aza-2′-deoxycytidine （5-aza-dC） on the biological behavior of 3 colon tumor cell lines,SW620, COLO205 and HT29 and to detect the expression changes of some tumor suppressor genes and oncogenes in these cell lines exposed to 5-aza-dC treatment. Methods All the tumor cell lines were treated with demethylation agent 5-aza-dC. Flow cytometry was applied to detect tumor cell cycle distribution. Cell apoptosis analysis was performed with annexin V/propidium iodide method. Migration assay and transwell invasion assay were carried on to measure the migration and invasion abilities of SW620 cells with or without 5-aza-dC treatment. In addition, RT-PCR was carried out to examine the expression changes of 3 tumor suppressor genes and 3 oncogenes. Results After 5-aza-dC treatment, tumor cell cycle was arrested at G2/M phase. The occurrence of apoptosis in 5-aza-dC treated group increased significantly. 5-aza-dC also significantly inhibited the migration and invasion abilities of tumor cell lines. The expressions of tumor suppressor genes were restored while those of oncogenes were remain unchanged. Conclusions 5-aza-dC can arrest cell cycle, induce apoptosis and inhibit the migration and invasive potential of colon tumor cell lines.