长链非编码RNA BAALC-AS1的m6A 甲基化修饰在食管鳞状细胞癌中的作用及机制研究

M6A methylation as a dynamic modification of coding RNA and non-coding RNA has become a new way of genetic information regulation, participate in the regulation of the pathological process of many kinds of diseases. However, m6A methylation has made some progress in the modification of coding RNA, but the modification mechanism of m6A methylation for long non-coding RNA (lncRNA) is still unknown. At present, we have found that lncRNA BAALC-AS1 (Homo sapiens BAALC antisense RNA 1) has copy number amplification in ESCC through human whole genome sequencing and is highly expressed in ESCC cell lines. After knockdown of BAALC-AS1 expression in ESCC cell lines, cell proliferation, migration and invasion abilities were inhibited. In addition, the overall level of m6A methylation in ESCC was low, and the ALKBH5 was highly expressed, and the ALKBH5 could regulate the expression of BAALC-AS1 and its m6A methylation level. Meanwhile, m6A methylated recognition protein YTHDF2 interacted with BAALC-AS1. Based on the previous experimental results, this project will further explore the role of BAALC-AS1 in ESCC and clarify ALKBH5 can modify the m6A methylation of BAALC-AS1 through YTHDF2 dependent pathway, so as to promote the of progress of ESCC. In order to provide new ideas for clinical diagnosis and treatment.

m6A甲基化作为编码RNA和非编码RNA上发生的动态修饰已成为一种全新的遗传信息调控方式，参与调节多种疾病的病理过程。目前，m6A甲基化对于编码RNA的修饰取得一定进展，但其对于长链非编码RNA的修饰机制仍不清楚。我们通过人类全基因组测序发现，长链非编码RNA BAALC-AS1在食管鳞癌中存在拷贝数扩增且在食管鳞癌细胞系中高表达，具有促进细胞增殖、迁移、侵袭能力。此外，食管鳞癌RNA整体水平的m6A甲基化呈低水平，去甲基化酶ALKBH5可以调控BAALC-AS1的表达及其m6A甲基化水平。同时，m6A甲基化识别蛋白YTHDF2与BAALC-AS1存在相互作用。本项目将依据前期实验结果的基础上深入探究BAALC-AS1在食管鳞癌中的作用及机制并阐明去甲基化酶ALKBH5可通过YTHDF2依赖途径修饰BAALC-AS1的m6A甲基化从而促进肿瘤的发生发展。以期为临床诊治提供新思路。

长链非编码RNA （long noncoding RNA, lncRNA）参与多种癌症的进展，但其具体机制尚不清楚。我们通过人类全基因组测序发现，长链非编码RNA BAALC Antisense RNA 1（BAALC-AS1）在食管鳞癌中存在拷贝数扩增且在食管鳞癌组织和细胞系中高表达，并与食管鳞癌恶性表型相关。本研究旨在探讨lncRNA BAALC-AS1调控食管鳞癌恶性表型的具体机制。体内和体外实验均表明，BAALC-AS1促进食管鳞癌细胞增殖、迁移和侵袭。BAALC-AS1直接与蛋白质G3BP Stress Granule Assembly Factor 2（G3BP2）相互作用，从而抑制G3BP2对c-Myc RNA 3′UTR的降解，从而导致c-Myc表达积累。此外，c-Myc可作为转录因子直接结合到BAALC-AS1的启动子区域，从而诱导其表达。综上，本研究将揭示食管鳞癌中 BAALC-AS1 的组织分布特点及其作用机制，阐明 BAALC-AS1/G3BP2/c-Myc 反馈环路在食管鳞癌发生发展中的作用。这可能为食管鳞癌的治疗提供一个新的治疗靶点并促进新的治疗策略发展。