miR-34a通过调控雄激素受体基因抑制前列腺癌细胞系LNCaP增殖

目的：探究miR-34a对雄激素受体（AR）基因的调控作用及对前列腺癌（PCa）LNCaP细胞增殖、凋亡的影响。方法：收集2016年10月至2019年9月本院泌尿外科行前列腺穿刺活检确诊为PCa患者组织标本36例，另取同期行手术治疗切除的良性前列腺增生（BPH）组织标本41例。体外培养LNCaP细胞，分别转染miR-34a mimics（mimics组），miR-34a mimic NC（NC组），设正常生长细胞为空白对照组（BC组），另在mimics组基础上转染AR过表达（AR过表达组）载体及其对照（AR对照组），采用CCK-8试剂盒检测细胞活性，Annexin V-FITC/PI双染色流式细胞凋亡检测试剂盒检测细胞凋亡率，实时定量PCR（RT-qPCR）检测miR-34a及AR mRNA表达水平，免疫印迹法检测AR蛋白、细胞周期蛋白D1（cyclinD1）及原癌基因产物（c-Mcy）、细胞凋亡相关蛋白（Bcl-2、Bax、capase-3）的表达水平。结果：与BPH组织比较，PCa组织中miR-34a表达水平显著降低（P<0.05），AR mRNA及蛋白表达水平均显著增加（P<0.05）；与BC、NC组比较，mimics组LNCap细胞miR-34a表达水平、细胞凋亡率、Bax蛋白表达水平显著增加（P<0.05），AR、Cyclin D1、Bcl-2、Bax蛋白表达水平显著降低（P<0.05），同一时间LNCap细胞活力均显著降低（P<0.05）；双荧光素酶实验结果显示，miR-34a与AR可能存在一定的调控关系，过表达AR基因可逆转miR-34a mimics对LNCaP细胞增殖抑制，促进凋亡作用。 结论：miR-34a可能通过调控AR抑制前列腺癌LNCaP细胞增殖，促进其凋亡。

miR-34a inhibits proliferation of prostate cancer LNCaP cells by regulating androgen receptor gene

AIM: To explore the effect of microRNA-34a (miR-34a) on androgen receptor gene (AR) targeting regulation and proliferation and apoptosis of prostate cancer (PCa) LNCaP cells. METHODS: Thirty-six patients with PCa confirmed by prostate biopsy in urology department of our hospital were collected from October 2016 to September 2019, and 41 cases of benign prostatic hyperplasia (BPH) tissue samples were taken and operated at the same time. LNCaP cells were cultured in vitro and transfected with miR-34a mimics (mimics group), miR-34a mimic NC (NC group) respectively, and normal growth cells were set as blank control group (BC group). In addition, on the basis of mimics group, the AR over-expression vector (AR over-expression group) and its control group (AR control group) were transfected. The cell activity was detected by CCK-8 kit, the apoptosis rate was detected by Annexin V-FITC/PI double staining flow cytometry test kit, the expression of miR-34a and AR mRNA was detected by real-time quantitative PCR (RT-qPCR), the expression of AR protein, CyclinD1, c-Myc and apoptosis-related proteins (Bcl-2, Bax, capase-3) was detected by Western blotting. RESULTS: Compared with BPH tissues, the expression of miR-34a in PCa tissues decreased significantly (P<0.05), and the expression of AR mRNA and protein increased significantly (P<0.05). Compared with BC and NC group, miR-34a expression level, apoptosis rate and Bax protein expression level of LNCaP cells in mimics group increased significantly (P<0.05), the expression levels of AR, Cyclin D1, c-Myc and Bcl-2 decreased significantly (P<0.05), the activity of LNCaP cells decreased significantly at the same time (P<0.05). The dual-luciferase assay showed that miR-34a may have a direct targeting relationship with AR. Over-expression of AR gene could reverse the inhibition of miR-34a mimics on LNCaP cell proliferation and promote apoptosis. CONCLUSION: miR-34a may inhibit the proliferation and promote the apoptosis of prostate cancer LNCaP cells by regulating AR gene.