miR-17-5p在大鼠垂体泌乳素腺瘤MMQ细胞耐药中的作用

目的：探讨microRNA-17-5p（miR-17-5p）在大鼠垂体泌乳素腺瘤MMQ细胞耐药中的作用及相关机制。方法：利用miR-17-5p类似物及拮抗物分别过表达和抑制大鼠垂体泌乳素腺瘤MMQ细胞中miR-17-5p的表达，并采用实时荧光定量PCR（RT-qPCR）法进行检测。利用CCK-8法检测miR-17-5p表达调控前后细胞增殖以及对卡麦角林（CAB）治疗反应的变化。通过生物信息学方法预测miR-17-5p的靶点基因，然后采用荧光素酶报告检测法进行验证，继而用qRT-PCR及Western blot法检测miR-17-5p对靶基因表达的影响。慢病毒细胞转染过表达MMQ细胞中的PTEN基因，用Western blot检测PTEN的表达水平，并采用CCK-8法检测PTEN过表达对MMQ细胞耐药性的影响。结果：miR-17-5p过表达可促进MMQ细胞的增殖，而miR-17-5p敲减则能抑制MMQ细胞的增殖。miR-17-5p敲减能上调MMQ细胞对CAB治疗的敏感性，相反，miR-17-5p过表达则显著降低MMQ细胞对CAB治疗的敏感性。生物信息学方法预测PTEN为miR-17-5p潜在作用靶点，荧光素酶报告检测法进一步验证了两者的相互作用关系，同时miR-17-5p过表达的MMQ细胞中PTEN mRNA及蛋白表达量显著下降，而miR-17-5p敲减的MMQ细胞中PTEN mRNA及蛋白表达量显著上升。PTEN表达上调能部分逆转miR-17-5p过表达引起的MMQ细胞对CAB治疗敏感性降低。结论：miR-17-5p可通过下调PTEN的表达促进MMQ细胞增殖并降低其对CAB治疗的反应。

Roles of microRNA-17-5p in the resistance of MMQ cells to Cabergoline

Objective: To study the roles of microRNA-17-5p may play in the resistance of MMQ cells to dopamine agonists. Methods: MMQ cells were either treated with miR-17-5p mimics or miR-17-5p inhibitor to regulate the expression of miR-17-5p in vitro qPCR was used to verify the transfection efficiency. After treatment, cell viability and its response to CAB was determined with CCK-8 assays. The target gene of miR-17-5p was predicted and confirmed via bioinformatics analysis and luciferase reporter assays. The expression of PTEN was analyzed by qPCR and Western Blotting. In addition we deployed CCK-8 assay to evaluate the response to CAB of MMQ cells which were initially treated with lentiviral vector containing PTEN. Results: Overexpression of miR-17-5p could promote the proliferation of MMQ cells and suppress CAB cytotoxicity. On the contrary, down-regulated of the expression of miR-17-5p could effectively inhibit proliferation and boost susceptibility to CAB in MMQ cells. The bioinformatics database identified the potential target of miR-17-5p and the luciferase reporter assay confirmed that PTEN was the direct target of miR-17-5p. While the expression of PTEN was down-regulated in miR-17-5p over-expressed MMQ cells, the expression of PTEN was up-regulated in miR-17-5p knockdown MMQ cells. Furthermore, PTEN over-expression was able to reverse the drug resistance induced by miR-17-5p on CAB treatment. Conclusion: miR-17-5p promotes MMQ proliferation and mediates CAB resistance by targeting PTEN.