Meox2调控PI3K/AKT信号通路对乳腺癌细胞的增殖及机制的影响

Effects of Meox2 on the proliferative mechanism of breast cancer via PI3K/AKT signalling pathway

目的:探究间充质同源盒蛋白(Meox2)对乳腺癌细胞增殖能力及其机制的影响。方法:体外培养人乳腺癌细胞株MCF-7,腺病毒转染调高细胞Meox2基因的表达,常规无额外基因序列添加的人乳腺癌细胞株MCF-7细胞设为Control组,含有Meox2基因的腺病毒(Ad-Meox2)转染细胞后设为Ad-Meox2组,以空载体Ad-GFP转染细胞后设为Ad-GFP组。荧光显微镜观察其转染率。采用MTT法和流式细胞仪分别验证过表达的Meox2对乳腺癌细胞在24、48、72 h后细胞的增殖及周期的变化。采用Western blot检测细胞中Meox2及其下游PI3K/AKT通路蛋白的表达。结果:腺病毒转染的MCF-7细胞中Meox2基因表达上调,转染率为95%以上。MTT显示,Ad-Meox2组可明显呈时间依赖性地抑制细胞增殖(P<0.05)。流式细胞仪检测显示Ad-Meox2组可显著阻滞细胞周期的进行,使更多的细胞停滞于S期与G2/M期(P<0.05),同时,阻滞细胞进入下一个周期,即G0/G1期(P<0.05)。Western blot显示各组的MCF-7细胞中PI3K和AKT含量无明显变化(P>0.05),但Ad-Meox2组的p-PI3K和p-AKT蛋白含量较Control组明显下降(P<0.05)。结论:Meox2基因可通过PI3K/AKT信号通路抑制乳腺癌细胞周期的进程,进而抑制乳腺癌细胞的增殖能力,提示Meox2可能是乳腺癌新的治疗靶点。

Objective:To explore the relationship between Meox2 and the proliferative mechanism of breast cancer.Methods:Breast cancer MCF-7 was cultured in vitro.The expression of the Meox2 gene was up-regulated using adenovirus.Conventional breast cancer MCF-7 cells without additional gene sequence addition were defined as the Control group,and adenovirus(Ad-Meox2) transfected cells containing the Meox2 gene were set as the Ad-Meox2 group.The empty vector(Ad-GFP) transfected cells were set to the Ad-GFP group.The transfection rate was observed by a fluorescence microscope.The expressions of Meox2 and its downstream PI3/AKT pathway protein were detected by use of western blot.MTT and flow cytometry were used to verify the proliferation and cell cycle of breast cancer with the stimulation of over-expressed Meox2 at 24,48 and 72 h respectively.Results:After adenovirus infection,the Meox2 gene was expressed in the MCF-7 cells with an infection rate of over 90%.Initially,MTT revealed that the Ad-Meox2 group obviously inhibited cell proliferation in a time-dependent manner(P<0.05).In addition,flow cytometry demonstrated that MCF-7 cells in the Ad-Meox2 group were significantly arrested for cell cycle progression.More cells were arrested in S phase and G2/M phase(P<0.05).At the same time,it blocked the cells into the next cycle,G0/G1 phase(P<0.05).Furthermore,Total expressions of PI3K and AKT protein remain unchanged in MCF-7 cells,while the levels of p-PI3K and p-AKT protein were significantly decreased in the Ad-Meox2 group(P<0.05).Conclusion:Meox2 gene might inhibit the cell cycle progression of breast cancer through PI3k/AKT signaling pathway,and inhibit the proliferation of breast cancer cells,suggesting that Meox2 may be a new therapeutic target for breast cancer.