p53调控信号转导与转录激活因子3信号通路对肺癌细胞增殖凋亡的影响

Downregualtion of p53 promotes cell proliferation and migration and inhibits apoptosis by targeting signal transducer and activators of transcription 3 in lung cancer

目的观察p53调控信号转导与转录激活因子3(STAT3)的调控关系,及对肺癌细胞增殖、迁移、侵袭及凋亡的影响。方法A549细胞分别转染p53、STAT3过表达质粒、si-p53 RNA和si-STAT3 RNA,采用Western blot法检测p53蛋白和STAT3蛋白的变化;A549细胞分别转染p53和STAT3过表达质粒,采用细胞计数试剂盒(CCK-8)方法检测细胞增殖,采用流式细胞术AV-碘化丙锭(PI)双染法检测转染后凋亡,Transwell法检细胞迁移能力和侵袭能力。结果过表达p53能显著下调STAT3蛋白,敲低p53后显著上调STAT3蛋白,敲低p53后A549细胞增殖速度明显增加(0.448±0.034比0.328±0.011,P<0.05),过表达p53后能抑制细胞的迁移(73.3±8.82比133.0±14.5,P<0.05)和侵袭(63.3±8.82比108.0±11.72,P<0.05)能力,并且促进凋亡水平(11.0±2.082比4.0±0.577,P<0.05)。同时过表达p53和STAT3能消除上述功能。结论p53能负向调控STAT3的表达,从而抑制其增殖和凋亡能力。

Objective To explore the relationship between p53 and signal transducer and activators of transcription 3 (STAT3) gene, and detect the effects of p53 and STAT3 on proliferation, migration, invasion and apoptosis of lung cancer cells. Methods Transfected p53 vector, STAT3 vector, si-p53 or si-STAT3 into A549 cells respectively. The expression of p53 and STAT3 were detected by Western blotting assay. Cell counting kit-8 (CCK-8) assay was performed to evaluate cell proliferation;Transwell assay to measure cell migration and invasion;Annexin V/propidium iodide (AV-PI) double staining and flow cytometry were adopted to detect cell apoptosis. Results The STAT3 protein expression was downregulated when overexpressed p53 protein. Meanwhile, STAT3 protein expression was upregulated when p53 protein was knockdown. After knockdown of p53, the proliferation rate of A549 cells was significantly increased (knockdown group: 0.448±0.034 vs. control group: 0.328±0.011)(P<0.05). The migration (ovexpressed group: 73.3±8.82 vs. control group: 133.0±14.5) and invasion (ovexpressed group: 63.3±8.82 vs. control group: 108.0±11.72) abilities was significantly decreased and the the level of apoptosis (ovexpressed group: 11.0±2.082 vs. control group: 4.0±0.577) was increased when downregulated p53 protein (all P<0.05). However, the above-mentioned functions were disappeared when increased p53 protein and STAT3 protein simultaneously. Conclusion p53 negatively regulates the expression of STAT3, thus inhibiting the ability of proliferation, migration and invasion and increased apoptosis.