[摘 要] 目的：探究miR-1224-5p在前列腺癌细胞增殖、迁移与凋亡中的生物学作用及其表达调控机制。方法：选用人前列 腺癌细胞PC3、DU145、LNCaP、22Rv1和正常前列腺上皮细胞RWPE-1，利用qPCR法检测miR-1224-5p在前列腺癌细胞中的表 达。使用脂质体转染技术分别将 miR-1224-5p 模拟物（mimic）、抑制剂（inhibitor）及相应的阴性对照（NC）质粒转染至 PC3 和 DU145细胞中，qPCR法验证转染效率 ，采用 CCK-8 实验、平板克隆形成实验、划痕愈合实验和流式细胞术分别检测转染 miR-1224-5p mimic与inhibitor对细胞增殖、迁移和凋亡的影响。借助SRAMP网站预测pri-miR-1224-5p序列中潜在的N6 -甲基腺 苷（m6 A）修饰位点，通过甲基化RNA免疫沉淀实验（MeRIP）验证预测结果，qPCR法检测m6 A修饰关键调控分子甲基转移酶3 （METTL3）在前列腺癌细胞中的表达，CCK-8实验和Transwell实验分别检测转染METTL3 siRNA对PC3和DU145细胞增殖和 迁移的影响，qPCR法和MeRIP检测METTL3介导的m6 A修饰对miR-1224-5p表达的调控作用。结果：miR-1224-5p在前列腺癌 细胞中均呈高表达（均 P < 0.01）。转染 miR-1224-5p mimic能够促进PC3和DU145细胞增殖、迁移并抑制细胞凋亡（P < 0.05 或 P < 0.01），转染miR-1224-5p inhibitor能够抑制 PC3 和 DU145 细胞增殖、迁移并诱导细胞凋亡（P < 0.05 或 P < 0.01）。pri-miR1224-5p具有m6 A修饰位点；METTL3在前列腺癌细胞中均呈高表达（均P < 0.01），转染METTL3 siRNA能够抑制PC3和DU145 细胞的增殖和迁移（均P < 0.01）；METTL3介导的m6 A修饰能够调控miR-1224-5p的表达。结论：miR-1224-5p受METTL3介导 的m6 A修饰调控，从而在前列腺癌细胞中呈高表达，下调miR-1224-5p能够抑制前列腺癌细胞的增殖、迁移并诱导细胞凋亡。

[Abstract] Objective: To investigate the biological role of miR-1224-5p in the proliferation, migration and apoptosis of prostate cancer cells, as well as its regulatory mechanism of expression. Methods: Human prostate cancer cells (PC3, DU145, LNCaP, 22Rv1) and normal prostate epithelial RWPE-1 cells were selected for this study. The expression of miR-1224-5p in prostate cancer cells was detected by qPCR. miR-1224-5p mimic, inhibitor and corresponding negative control (NC) plasmids were transfected into PC3 and DU145 cells by liposome transfection technology, respectively. The transfection efficiency was verified by qPCR. The effects of miR-1224-5p mimic and inhibitor on cell proliferation, migration and apoptosis were detected by CCK-8 assay, plate clone formation assay, scratch healing assay and flow cytometry. The potential N6 -methyladenosine (m6 A) modification sites in the pri-miR-1224-5p sequence were predicted using SRAMP website, and the prediction results were verified using methylated RNA immunoprecipitation (MeRIP). The expression of methyltransferase 3 (METTL3), a key methyltransferase involved in m6 A modification, in prostate cancer cells was detected by qPCR. CCK-8 assay and Transwell assay were used to detect the effect of METTL3 siRNA transfection on the proliferation and migration of PC3 and DU145 cells. The regulatory effect of METTL3-mediated m6 A modification on the expression of miR-1224-5p was detected by qPCR and MeRIP. Results: miR-1224-5p was upregulated in prostate cancer cells (all P < 0.01). Transfection with miR-1224-5p mimic promoted the proliferation, migration and inhibited the apoptosis of PC3 and DU145 cells (P < 0.05 or P < 0.01). Conversely, miR-1224-5p inhibitor suppressed the proliferation, migration and induced apoptosis of PC3 and DU145 cells (P < 0.05 or P < 0.01). pri-miR-1224-5p contained m6 A modification sites. METTL3 was highly expressed in prostate cancer cells (all P < 0.01). Transfection of METTL3 siRNA inhibited the proliferation and migration of PC3 and DU145 cells (all P < 0.01). METTL3-mediated m6 A modification regulated the expression of miR-1224-5p. Conclusion: miR-1224-5p is upregulated in prostate cancer cells through METTL3-mediated m6 A modification. Down-regulation of miR-1224-5p can inhibit the proliferation, migration and induce apoptosis of prostate cancer cells.

国家自然科学基金（No. 82160465）