BAP31调节膀胱癌干细胞干性及其相关机制研究

Bladder cancer is one of the most common malignancy in the world. However, the progress in bladder cancer management has been modest over the past decades. More and more reports show that there is a small sum of cells in the tumor tissue named cancer stem cells and these cells are probably accounted for the metastasis and relapse of cancer. B cell receptor associated protein 31 (BAP31) is an important cytokine, which is associated with apoptosis and protein pyrolysis. BAP31 also play a key role in regulating hESC stemness and survival through control of EpCAM expression. Furthermore, many reports have showed that BAP31 exerts its function in many types of cancers. In this study, we try to focus on the biological function of BAP31 in bladder cancer stem cells, exploiting its potential role in regulating the differentiation of tumor stem cells. The expression of BAP31 in bladder cancer cell line UC5 is stable knockdown by shRNA, and the bladder cancer stem cells are then sorted through flow cytometry. Tumor stem cell related gene expression, drug resistance and the ability of invasive and metastasis are investigated in BAP31 knockdown tumor stem cells. To determine the influence of BAP31 on the ability of in vivo tumorigenesis of tumor stem cells, NOD/SCID mice are used. After BAP31 knockdown bladder cancer stem cells being implanted into these mice, the tumor size is assessed every week. Meanwhile, in order to confirm the results harvested from BAP31 knockdown cells, studies are also performed in BAP31 knockout cells generated by Crispr-Cas9 technique and BAP31 over-expression cells, respectively. This project tries to unlock the role of BAP31 in the differentiation of tumor stem cells and enriches the molecular biology knowledge for cancer treatment.

越来越多研究表明，癌症干细胞是导致癌症难以治愈的根本原因。BAP31是一个与细胞凋亡、蛋白裂解相关的细胞因子，在干细胞分化、癌症发生中发挥重要作用。本项目拟研究BAP31在膀胱癌干细胞中的功能作用，探索其影响癌症干细胞分化的分子机制。我们采用shRNA技术，在膀胱癌细胞UC5中对BAP31表达进行稳定敲低，并运用流式细胞术分选膀胱癌干细胞。在BAP31敲低癌症干细胞中，进行自我更新、药物抗性以及侵袭转移能力等的测定。将BAP31敲低癌症干细胞植入NOD/SCID小鼠后检测体内成瘤情况，研究BAP31基因对癌症干细胞体内致瘤能力的影响。同时，分别运用Crispr-Cas9基因编辑技术和基因过表达技术在UC5中进行BAP31敲除和过表达，验证BAP31在癌症干细胞中的作用。本项目将阐明BAP31对膀胱癌干细胞分化的影响，为癌症发病机制研究及有效治疗方法的提出提供试验依据。

B细胞受体相关蛋白31（B cell receptor associated protein 31, BAP31）是一个内质网膜蛋白，参与内质网相关蛋白裂解、细胞凋亡以及对T细胞受体调节等生物学进程。本项目研究结果进一步表明，BAP31可能通过多种方式参与癌症发生发展。项目实施中的主要的学术成果包括：1.验证了BAP31对肿瘤细胞增殖以及转移能力的影响；2.发现BAP31能够影响肿瘤细胞凋亡与细胞周期进程；3.表明干扰BAP31能够调控肿瘤干细胞干性；4.阐明内质网应激在BAP31调控的肿瘤进程中的作用；5. 证实多个BAP31结合蛋白，并发现多条BAP31调控通路；6.首次提出BAP31能够通过影响表观遗传修饰参与肿瘤进程。此外，依托本项目的实施，发表相关SCI论文5篇。