5-Aza-CdR诱导抑癌基因PTEN重新表达对乳腺癌细胞的影响及机制

目的观察5-氮杂-2’-脱氧胞苷(5-Aza-CdR)对人乳腺癌细胞系MCF-7增殖、凋亡及体外侵袭能力的影响并初步探讨其机制。方法体外培养MCF-7细胞,采用不同浓度的5-Aza-CdR(1×10-6、2×10-6、5×10-6和1×10-5mol/L)分别作用24h、48h和72h,分别采用MTT法检测细胞增殖抑制率、流式细胞仪检测细胞凋亡、Transwell法检测细胞侵袭能力、Western-blot检测PTEN和VEGF-C蛋白表达的变化。结果经不同浓度的5-Aza-CdR作用后,MCF-7细胞的增殖受到不同程度的抑制并发生凋亡,细胞侵袭能力也发生不同程度的降低,且其作用随浓度增加和时间延长而增强(P<0.05)。在5-Aza-CdR作用后,MCF-7细胞PTEN的表达逐渐增强,而VEGF-C的表达逐渐减弱。结论 5-Aza-CdR可抑制乳腺癌细胞增殖、诱导其发生凋亡、降低其体外侵袭能力,其可能是通过去甲基化作用使抑癌基因PTEN重新表达并下调VEGF-C的表达而发挥作用的。

Anti-oncogene PTEN reactivation induced by 5-Aza-CdR and its effects on breast cancer cells

Objective To observe the effects of 5-Aza-CdR on the proliferation, apoptosis and invasive ability in vitro of human breast cancer cells line MCF-7 and explore the mechanism. Methods MCF-7 cells were cultured in vitro. Different concentrations of 5-Aza-CdR （1×10-6, 2×10-6, 5×10-6 and 1×10-5mol/L） were added to culture for 24 h, 48 h and 72 h. MTT assay was used to detect the inhibition rate of proliferation. Flow cytometry was used to measure the apoptosis rate. Transwell assay was used to observe the invasive ability. The protein expressions of PTEN and VEGF-C were detected by Western-blot. Results The proliferation was inhibited, apoptosis was induced and the invasive ability decreased when treated by the different concentrations of 5-Aza-CdR. The effects were enhanced with concentration increased and time extended （P〈0. 05 ）. The expression of PTEN in MCF-7 cells was increased after being treated by 5-Aza-CdR, VEGF-C decreased. Conclusion 5-Aza-CdR could inhibit the proliferation, induce the apoptosis and decrease the invasive ability in vitro of MCF-7 cells. It might reactivate the expression of PTEN and down-regulate the expression of VEGFC by demethylation induced by 5-Aza-CdR.