miR-506-3p通过靶向MTDH增加前列腺癌细胞的化学敏感性

目的研究miR-506-3p对前列腺癌细胞化学敏感性的影响及其作用机制。方法用RT-qPCR检测miR-506-3p和MTDH在前列腺癌细胞系和正常前列腺细胞系中的表达水平;以紫杉醇为诱导药物构建人前列腺癌耐药细胞株PC-3/PTX,将PC-3/PTX细胞随机分为5组对照组、NC mimic组、miR-506-3p mimic组、LV-MTDH组、mimic+MTDH组,利用Lipofectamine 3000转染试剂盒分别转染对应质粒。检测其存活率、IC50值、克隆细胞数目、凋亡率以及凋亡相关蛋白的表达水平;构建MTDH野生型(WT)和突变型(MUT),用双荧光素酶报告基因实验验证miR-506-3p与MTDH之间的靶向关系;Western blot检测miR-506-3p mimic处理后PC-3/PTX细胞中MTDH的蛋白表达水平。结果miR-506-3p在前列腺癌细胞中低表达,而MTDH高表达;miR-506-3p在PC-3/PTX细胞中的表达量显著低于在前列腺癌细胞PC-3中的表达量;相比于对照组和NC mimic组,miR-506-3p mimic组的PC-3/PTX细胞的存活率、IC50值、克隆细胞数目及Bcl-2表达明显降低,凋亡率及Bax表达明显升高;MTDH野生型较突变型能使荧光素酶活性显著下降;miR-506-3p mimic组PC-3/PTX细胞中MTDH蛋白表达水平显著低于对照组和NC mimic组;相比于对照组,miR-506-3p mimic组中PC-3/PTX细胞克隆数目显著减少,凋亡率升高,而LV-MTDH组与之相反;相比于LV-MTDH组,mimic+MTDH组PC-3/PTX细胞中MTDH的表达量显著下降,细胞克隆数目减少,凋亡率升高。结论miR-506-3p通过靶向抑制MTDH的表达能增强人前列腺癌耐药细胞株PC-3/PTX的化学敏感性。

MiR-506-3p increases chemosensitivity of prostate cancer cells by targeting MTDH

Objective To elucidate the effect of miR-506-3p on the chemosensitivity of prostate cancer cells and its mechanism. Methods The expression levels of miR-506-3p and MTDH in prostate cancer cell lines and normal prostate cell lines were examined by RTq PCR. The human prostate cancer resistant cell line PC-3/PTX was constructed with paclitaxel as the inducing drug,PC-3/PTX cells were randomly divided into 5 groups: control group,NC mimic group,miR-506-3p mimic group,LV-MTDH group,mimic + MTDH group,and were transfected with corresponding plasmids by using Lipofectamine 3000 Stain kit. The survival rate,IC50 value,number of cloned cells,apoptosis rate and expression levels of apoptosis-related proteins were detected. The wild-type and mutant-type MTDH were constructed. The dual-luciferase reporter gene assay was employed to verify the targeting relationship between miR-506-3p and MTDH. Western blot was used to detect the expression of MTDH protein in PC-3/PTX cells after miR-506-3p mimic treatment. Results The expression of miR-506-3p was low in prostate cancer cells,while the expression of MTDH was high in prostate cancer cells. The expression level of miR-506-3p in PC-3/PTX cells was significantly lower than that in prostate cancer cells PC-3. Compared with the control group and NC mimic group,the survival rate,IC50 value,number of cloned cells and the expression of Bcl-2 in PC-3/PTX cells of miR-506-3p mimic group were significantly decreased,while the apoptosis rate and the expression of Bax were significantly increased. The wild-type MTDH showed a significant decrease in luciferase activity compared with mutant-type MTDH. The expression level of MTDH protein in PC-3/PTX cells of miR-506-3p mimic group was significantly lower than those in the control group and NC mimic group. Compared with the control group,the number of PC-3/PTX cell clones was significantly decreased in the miR-506-3p mimic group,and the apoptosis rate was increased,while those in the LV-MTDH group were opposite. Compared with LV-MTDH group,the expression of MTDH and the number of cell clones in PC-3/PTX cells of mimic + MTDH group were significantly decreased,and the apoptosis rate was increased. Conclusion miR-506-3p can enhance the chemosensitivity of human prostate cancer resistant cell line PC-3/PTX by targeting inhibition of MTDH expression.