H19阻止miRNA-93a对自噬的抑制而增敏DRD2受体激动剂疗效的机制研究

垂体泌乳素腺瘤首选药物治疗，如卡麦角林。我们对CAB的研究表明，CAB诱导细胞发生自噬依赖的细胞死亡，敲低ATG7能增加CAB治疗的耐药性。我们前期还针对敏感和耐药泌乳素腺瘤进行芯片检测，发现长链非编码RNA-H19在敏感中高表达，而miRNA-93a表达水平下降。体内外i实验验证miRAN-93a能够降低CAB的药物敏感性。进一步研究发现miRNA-93a能够抑制细胞的自噬水平和ATG7蛋白表达，并且生物信息学分析miRNA-93a和H19存在靶向结合位点。我们由此提出设想H19能够通过抑制miRNA-93a的表达，促进自噬水平，增加药物敏感性。本课题后续将采用RNA pull down等技术，证明H19和miRNA-93a直接结合；构建大鼠原位瘤模型体内验证机制；最后检测患者血液中H19水平作为判断药物治疗敏感性的生物标志物。本课题从H19角度全新阐释泌乳素瘤耐药机制。

Cabergoline is the first-line therapy of prolactinomas. Our recent study indicates that cabergoline induces autophagy of pituitary tumor cells, and finally results in autophagy-dependent cell death. Knockdown of ATG7 rescues cabergoline-mediated cell death and then increases the resistance of pituitary tumor to cabergoline treatment. In addition, according to the microarray results of sensitive- and resistant- prolactinomas, we find that expression of long non-coding RNA (lncRNA)-H19 in sensitive prolactinomas is higher than that in resistant prolactinomas. However, the miRNA-93a is up-regulated in drug resistant prolacinomas. Meanwhile, we did some preliminary research and found that miRNA-93a could compromise the CAB effects in vitro and in vivo. Mechanically, overexpression of miRNA-93a decreased the LC3-II level,a classical biomaker of autophay, which induced by serum starvation in GH3 and MMQ cells. A another bioinformatics analysis indicates that H19 directly binds to miRNA-93a in some nucleotide sequences. Above all, we consider that H19 could enhance the effects of CAB by promoting autophagic cell death through decreasing miRNA-93a level. In order to further confirm our hypothesis, we need to investigate: ① the direct combination of H19 and miRNA-93a using the technique of RNA pull down and northern blot experiment; ②mechanism studies to demonstrate H19 promotes autophagy through decreasing miRNA-93a level in GH3 and MMQ cells; ③ the in vivo effect of cabergoline treatment using F344 rats with H19 knockdown;④ the serum H19 level of patients with prolactinoma, whether H19 is a sensitivity biomarker of prolactinomas to cabergoline treatment. This study from the axis of lncRNA H19-miRNA-93a-autophagy will give us insight into the novel mechanism of CAB treatment to prolactinomas. If successful, the findings from this study provide us a new avenue for treatment of clinical dopamine-resistant prolactinomas, which has far-reaching clinical significance and academic value.