MiR-148a对肺癌细胞放射敏感性的影响

目的探讨miR-148a对肺癌A549、H460以及H1299细胞放射敏感性的影响。方法根据不同的处理方法，分别按以下方式将肺癌A549、H460和H1299细胞进行分组。（1）将肺癌A549和H460细胞分为3组：空白对照组、4 Gy γ射线照射组和8 Gy γ射线照射组。采用实时定量PCR检测miR-148a的表达水平；（2）将肺癌A549细胞分为2组：空白对照组、miR-148a转染组；同时，将肺癌H460细胞分为2组：空白对照组、anti-miR-148a转染组。分别对转染2组细胞进行不同剂量的γ射线照射，并采用克隆形成实验方法来检测细胞增殖；（3）将肺癌A549和H1299细胞分为3组：空白对照组、miR-148a单独处理组、miR-148a和雌激素受体（ER）共转染组。分别对3组细胞进行不同剂量的γ射线照射，并采用克隆形成实验方法检测细胞生长情况。采用Student t-test对数据进行统计学分析，P < 0.05表示差异有统计学意义。结果实时定量PCR实验结果显示，γ射线照射能够显著下调肺癌A549和H460细胞中miR-148a的表达水平。克隆形成实验结果显示，与空白对照组相比，miR-148a转染能够显著增强肺癌A549细胞的放射敏感性，差异有统计学意义（t=12.16，P < 0.01），而anti-miR-148a转染能够显著降低肺癌H460细胞的放射敏感性，差异有统计学意义（t=11.93，P < 0.01）。同时，miR-148a过表达可以明显下调肺癌A549细胞中ER的mRNA及蛋白表达水平；而anti-miR-148a能够显著上调肺癌H460细胞中ER的mRNA及蛋白表达水平。另外，与miR-148a单独处理组相比，miR-148a和ER共转染组中miR-148a对肺癌A549和H1299细胞增殖的影响显著降低，差异有统计学意义（t=11.34、12.68，均P < 0.01）。结论照射可以诱导miR-148a的表达水平降低，人为过表达miR-148a能够抑制ER的蛋白表达水平，进而降低肺癌A549和H1299细胞的增殖能力，同时增强其放射敏感性。

Effect of miR-148a on the radiosensitivity of lung cancer cells

ObjectiveTo explore the effects of miR-148a on the radiosensitivity of lung cancer cell lines A549, H460, and H1299.MethodsLung cancer cells were divided into various groups based on different treatment methods. (1) A549 and H460 cells were classified into three groups:control, 4 Gy γ-irradiation, and 8 Gy γ-irradiation groups. miR-148a expression levels were analyzed through qRT-PCR. (2) A549 cells were categorized into two groups:control and miR-148a transfection groups. H460 cells were also divided into two groups:control and anti-miR-148a transfection groups. The cells were treated with different doses of γ-irradiation, and cell proliferation was detected through a clonogenic assay. (3) A549 and H1299 cells were grouped into three:control, miR-148a transfection, and miR-148a+ER transfection groups. The cells were treated with different doses of γ-irradiation, and the proliferation of A549 and H1299 cells was detected via clonogenic assay. Statistical significance was determined with SPSS and analyzed with Student t test. P < 0.05 was considered statistically significant.ResultsqRT-PCR analysis revealed that the miR-148a expression in the A549 and H460 cells treated with γ-irradiation decreased significantly. Clonogenic assays showed that miR-148a could sensitize A549 cells exposed to irradiation compared with that of the control group (t=12.16, P < 0.01). H460 cells were more resistant to irradiation in the presence of anti-miR-148a (t=11.93, P < 0.01). miR-148a overexpression could also downregulate the mRNA and protein levels of estrogen receptor (ER) in A549 cells, but anti-miR-148a could increase the mRNA and protein levels of ER in H460 cells. The miR-148a and ER overexpression significantly decreased the effect of miR-148a on the proliferation of A549 and H1299 cells (t=11.34, 12.68, respectively, both P < 0.01).ConclusionsIrradiation could decrease miR-148a expression levels, and miR-148a overexpression could downregulate the ER level and suppress the proliferation of A549 and H1299 cells, thereby enhancing the radiosensitivity of lung cancer cells.