环状RNA结合MAZ蛋白调控神经母细胞瘤中hnRNPK基因转录的作用及机制研究

本课题组新近发现：核不均一核糖核蛋白K(hnRNPK)促进神经母细胞瘤(NB)恶性进展，但其表达调控的分子机制不明；hnRNPK内含子来源的环状RNA(ci-hnRNPK)能通过结合MYC相关锌指蛋白(MAZ)，增强MAZ对NB组织和细胞中hnRNPK基因转录的促进作用。在此基础上，本项目拟深入解析转录因子MAZ与视网膜母细胞瘤结合蛋白4(RBBP4)相互作用、进而招募组蛋白乙酰化酶p300/CBP对NB中hnRNPK启动子活性及基因表达的调控作用；明确ci-hnRNPK与MAZ蛋白的相互作用及结构域，观测ci-hnRNPK对MAZ转录因子活性及hnRNPK基因表达的影响；在细胞和动物水平，观测过表达/敲低ci-hnRNPK、回补hnRNPK表达或MAZ功能对NB增殖、侵袭和转移的调控作用，有望阐明新型内源性环状RNA对hnRNPK表达的调控作用及机制，为NB的治疗提供新途径及理论依据。

Our recent studies reveal that heterogeneous nuclear ribonucleoprotein K (hnRNPK) facilitates the progression of neuroblastoma (NB), while the mechanisms regulating its expression remain largely unknown. In addition, circular RNA derived from the intron of hnRNPK (ci-hnRNPK) is able to bind to MYC associated zinc finger protein (MAZ) to promote the MAZ-facilitated hnRNPK gene transcription in NB tissues and cell lines. Based on these findings, this project is proposed to further elucidate the interaction between MAZ and RB binding protein 4 (RBBP4) and their roles in recruiting histone acetyltransferases p300/CBP and epigenetically regulating the promoter activity and expression of hnRNPK in NB. The interaction and domains of ci-hnRNPK and MAZ will be elucidated, and the regulatory effects of ci-hnRNPK on the activity of transcription factor MAZ and expression of hnRNPK gene will be investigated. The effects of over-expression or knockdown of ci-hnRNPK and rescue of hnRNPK expression or MAZ activity on the proliferation, invasion, and metastasis of NB will be observed in cultured cell lines and animal models. This study will elucidate the crucial functions and underlying mechanisms of endogenous circular RNA in regulating the hnRNPK expression, and will provide novel approach and theoretic basis for the therapeutics of NB.