MYC家族/miR-362/BAP31分子网络失调作为宫颈癌内在推手的研究

Cervical cancer is the most common female malignancy. HPV infection is an important extrinsic reason, however, pursuing for the intrinsic mechanism of tumor development is significant. Studies overseas reported that BAP31 is an ER transporter, which engaged in crtical biofunctions such as ER homeostasis and cellular apoptosis. Our previous study found BAP31 a novel cancer/testis antigen, of which expression profile was positively correlated with progression of cervical cancer, and which had effect on cellular behaviors like proliferation, apoptosis, cell cycle, invasion and migration. We also discovered that posttranscription modification should be blamed for the discontinuity expression of BAP31 from mRNA to protein in cervical cancer; miR-362 downregulated BAP31, which was confirmed by bioinformatics and labwork; the loss of transcriptive function of MYC family led to miR-362 low expression in cervical cancer; and bilateral links between BAP31 and Bip/Grp78 were symbolized by ceRNA and protein interaction, which suggested a complicated mechanism in cervical cancer. So, is that the regulation network mentioned above the inner promotion of cervical cancer? This project means to systematically interpret that molecular network dysregulation of MYC family, miR-362 and BAP31 is an inner promotion of cervical cancer, and to put forward new targets and fresh ideas for disease prevention and control.

宫颈癌是最常见的妇科恶性肿瘤，HPV感染是其重要的外在因素，而阐明发病的内在机制意义重大。国内外研究发现：BAP31是内质网转运蛋白，参与内质网稳态维持、细胞凋亡等重要生物过程。课题组前期证实：BAP31作为一种新的肿瘤/睾丸抗原，其表达与宫颈癌发生发展成正相关，影响增殖凋亡及侵袭迁移等细胞行为。我们还发现：BAP31在mRNA和蛋白水平表达不对等提示其在宫颈癌中高表达是转录后调控异常所致；生物信息学及预实验显示miR-362可负调节BAP31表达；临床小样本及分子生物学实验提示宫颈癌中MYC家族转录失能是miR-362下调的重要原因；进一步发现BAP31可与Bip/Grp78形成复合体、兼具ceRNA关系。那么，上述分子构成的调控网络是否为宫颈癌发生的内在推手？本课题拟系统探讨MYC家族、miR-362及BAP31分子网络失调促进宫颈癌发展的内在分子机制，为疾病的防治提供新靶点和新思路。

宫颈癌是最常见的妇科恶性肿瘤。我们课题组前期发现，BAP31是一种新的肿瘤/睾丸抗原，影响肿瘤细胞的多种生物学行为，可能是宫颈癌检测和治疗的关键靶点。此项课题针对BAP31的转录后调控机制，研究MYC家族/miR-362/BAP31分子网络在宫颈癌中的作用。.①收集临床宫颈癌患者和正常人宫颈组织标本，检测样本中miR-362及BAP31、MYC的表达水平，统计学分析三者之间及其与宫颈癌发生发展的关系。结果显示，宫颈癌组织中miR-362低表达，BAP31高表达，MYC高表达，且与肿瘤分期、生存期相关。.②在不同宫颈癌细胞系中进行细胞转染，分析BAP31和miR-362对宫颈癌细胞多种生物学行为的作用。结果发现miR-362可通过调控BAP31的表达，抑制细胞增殖，促进细胞凋亡，同时降低细胞侵袭迁移能力，BAP31的作用与之相反。.③构建裸鼠宫颈癌荷瘤模型，采用体内转染miR-362和抗体封闭BAP31的方式进行治疗观察。结果发现，在小鼠荷瘤模型中下调或抗体封闭BAP31，或转染miR-362模拟物，可有效减小肿瘤体积和重量，延长小鼠生存期。.④进一步机制研究发现，miR-362通过与BAP313’UTR区特异性结合调节BAP31的表达，激活TGFβ/Smad通路抑制宫颈癌细胞生长。BAP31通过调控Drebrin、M-RIP、SPECC1L、Nexilin表达和亚细胞定位，调节细胞侵袭迁移。BAP31可通过调控SERPINE2表达和分泌，促进肿瘤细胞增殖。.⑤拓展研究：从宫颈癌发病根源HPV感染入手，通过基因芯片对比分析，发现HPV感染后细胞中RNA结合蛋白IGFBP2上调明显，且有氧糖酵解明显改变。.⑥进一步通过RIP、me-RIP等研究发现，IGF2BP2调节MYC甲基化位点，调控有氧糖酵解，促进宫颈癌进展。为进一步阐明宫颈癌发病机制提供理论依据，为该疾病的治疗提供新靶点和新思路。