lncRNA-CPAT1通过RNA乙酰化酶NAT10调控细胞焦亡通路促进膀胱癌化疗耐药的机制研究

化疗耐药是膀胱癌复发和治疗失败的关键原因。细胞焦亡是一种新的细胞死亡形式，在肿瘤和免疫性疾病中起关键作用，但焦亡在调控膀胱癌化疗耐药的作用和机制尚不明确。我们预实验发现在膀胱癌耐药细胞和癌组织中焦亡基因是低表达的，但lncRNA-CPAT1是高表达，它与生存预后密切相关，它抑制膀胱癌细胞焦亡并促进体内外的化疗耐药。进一步发现它与RNA乙酰化酶NAT10结合，从而调控焦亡关键基因NLRP3和GSDMD的mRNA稳定性。由此我们提出膀胱癌化疗耐药新机制：lncRNA-CPAT1通过竞争性结合NAT10，减少NLRP3和GSDMD的RNA乙酰化导致该RNA降解增多，从2个环节抑制焦亡发生，从而促进膀胱癌化疗耐药。本研究拟进一步采用体内外实验，免疫共沉淀和高通量测序等技术，获得lncRNA-CPAT1通过NAT10调控膀胱癌焦亡和化疗耐药的可靠证据，为预测膀胱癌化疗敏感性和化疗增敏提供理论基础。

Chemoresistance is the main reason of relapse and treatment failure in bladder cancer. Pyroptosis is a new form of cell death, which plays a key role in tumor and immune diseases. However, the role and mechanism of pyroptosis in the regulation of chemotherapy resistance of bladder cancer are not clear. Our previous study found that lncRNA-CPAT1 was overexpressed in cisplatin resistant bladder cancer cell sublines and cancer tissues, but the genes of pyroptosis were down-regulated in these. The expression of lncRNA-CPAT1 was correlated with overall survival and disease-free survival. Through gain or loss of function, we demonstrated that lncRNA-CPAT1 significantly inhibited pyroptosis and then enhanced the chemoresistance of bladder cancer cells in vitro and vivo. Furthermore, we identified that lncRNA-CPAT1 binds to NAT10, an RNA acetylase and lysine acetyltransferase, by RNA pull down, mass spectrometry and RIP. LncRNA-CPAT1 also regulated the RNA stability of NLRP3 and GSDMD, which were the key pathway leading to pyroptosis. Therefore, we propose a new mechanism that lncRNA-CPAT1 competitively bound to NAT10, and reduced the RNA acetylation and expression of NLRP3 and GSDMD, leading to degradation of NLRP3 and GSDMD and then promoting the chemoresistance of bladder cancer. To gain the proof of lncRNA-CPAT1 regulates pyroptosis and chemoresistance of bladder cancer by NAT10, we will perform in vitro and vivo functional experiments, co-immunoprecipitation and next generation sequencing analysis. This study is aim to elucidate the function and mechanism of lncRNA-CPAT1 in bladder cancer and how they modulate the target genes by binding NAT10, to clarify the clinical significance of lncRNA-CPAT1 in bladder cancer recurrence, therapy resistance and prognosis, identify the new biomarker and target for chemoresistant bladder cancer cells targeting therapy.