miR-320通过调控Mcl-1对宫颈癌细胞凋亡的作用和机制研究

Cervical cancer is one of the most common malignancy in women. Abnormal regulation of apoptosis is closely related with tumorigenesis. Our preliminary findings showed that the expression of anti-apoptotic protein Mcl-1 was significantly higher in cervical cancer tissue when compared with corresponding normal tissue, and Mcl-1 expression profile was significantly associated with the pathological grade, tumor size, lymph node metastasis and prognosis. Bioinformatics analysis indicated that Mcl-1 is the target gene of miR-320, preliminary experiment found that miR-320 expression was significantly reduced in cervical cancer. So, we speculate that miR-320 may involved in the pathogenesis of cervical cancer via its regulation on Mcl-1. However, until now there is no a report about the regulation effect and mechanism of miR-320 on Mcl-1.In this study, we will firstly validate the target regulation of miR-320 on Mcl-1 by luciferase reporter genes assay; secondly, we will investigate the regulation mechanism of miR-320 on Mcl-1 and the effect on apoptosis of human cervical cancer cells, then explore the anti-apoptosis pathways which was mediated by Mcl-1. Finally, we will verify the effect and mechanism of miR-320 on apoptosis of cervical cancer cells via its regulation on Mcl-1 in vivo. This study is innovative and will provide a new theoretical basis for cervical cancer prevetion and treatment, which has important theoretical significance and clinical application value.

宫颈癌是女性最常见的恶性肿瘤之一。细胞凋亡调控异常与肿瘤发生密切相关。我们前期研究发现抗凋亡蛋白Mcl-1在宫颈癌显著高表达，其表达水平与宫颈癌病理分级、肿瘤直径、淋巴结转移及患者预后密切相关。生物信息学分析提示Mcl-1是miR-320调控的靶基因，预实验发现宫颈癌miR-320表达显著下调。因此，我们推测miR-320可能通过调控Mcl-1参与宫颈癌发病机制。然而，目前关于miR-320对Mcl-1的调控作用和机制的研究尚属空白。本研究拟采用荧光素酶报告基因技术验证miR-320与Mcl-1靶向关系；在人宫颈癌细胞水平，明确miR-320对Mcl-1的调控机制及对细胞凋亡的影响，探讨Mcl-1介导宫颈癌细胞抗凋亡途径；在体水平进一步验证miR-320通过调控Mcl-1对宫颈癌细胞凋亡的作用与机制。本研究具有创新性，可为宫颈癌防治提供新的理论依据，具有重要的理论意义和临床应用价值。

宫颈癌是女性最常见的恶性肿瘤之一。细胞凋亡调控异常与肿瘤发生密切相关。我们前期研究发现抗凋亡蛋白Mcl-1在宫颈癌显著高表达，其表达水平与宫颈癌病理分级、肿瘤直径、淋巴结转移及患者预后密切相关。生物信息学分析提示Mcl-1是miR-320调控的靶基因，预实验发现宫颈癌miR-320表达显著下调。因此，我们推测miR-320可能通过调控Mcl-1参与宫颈癌发病机制。然而，目前关于miR-320对Mcl-1的调控作用和机制的研究尚属空白。本研究拟采用荧光素酶报告基因技术验证miR-320与Mcl-1靶向关系；在人宫颈癌细胞水平，明确miR-320对Mcl-1的调控机制及对细胞凋亡的影响，探讨Mcl-1对宫颈癌细胞凋亡的作用和途径；在体水平进一步验证miR-320通过调控Mcl-1对宫颈癌细胞凋亡的作用与机制。我们研究结果表明宫颈癌患者血清及组织中miR-320表达水显著低于正常对照而Mcl-1显著高于正常对照(P<0.05)。宫颈癌患者miR-320及Mcl-1表达存在显著负相关(r = -0.389, P < 0.05)。荧光素酶报告基因技术证实miR-320与Mcl-1存在靶向调控关系。体外实验证实miR-320可以诱导宫颈癌细胞凋亡及caspase-3活性增加，而抑制宫颈癌细胞增殖，迁移侵袭 (P < 0.05, respectively)。裸鼠成瘤实验证实miR-320可以显著抑制宫颈癌细胞肿瘤形成。我们研究结果表明miR-320通过调控Mcl-1发挥抗肿瘤作用，参与宫颈癌发病机制。本研究具有创新性，为宫颈癌防治提供新的理论依据和实验依据，miR-320可成为宫颈癌患者临床诊断和治疗的新型分子标志物，本研究具有重要的理论意义和临床应用价值。