ANKRD13B基因DNA甲基化在结直肠癌发生发展中的作用及机制研究

抑癌基因的甲基化在肿瘤中起着重要作用。我们在结直肠癌（CRC）中通过甲基化芯片和CRISPR甲基化编辑技术，发现ANKRD13B启动子的“持续甲基化”现象，并由此导致表达缺失。ANKRD13B启动子有c-Jun结合位点，且在过表达c-Jun后甲基化水平升高；ANKRD13B可与DNA、RNA和METTL3结合，过表达后肿瘤侵袭转移能力减弱、Wnt靶基因上调且不依赖于Wnt信号通路激活。因此提出科学假说：c-Jun介导ANKRD13B的“持续甲基化”，从而抑制Wnt靶基因的转录或RNA的m6A甲基化修饰，进而下调Wnt靶基因表达，促进CRC侵袭和转移。本项目拟通过高通量技术筛选此机制中的未知分子，采用ChIP、MeRIP、Co-IP、载体构建、CRISPR甲基化编辑等技术进一步研究ANKRD13B甲基化的上下游分子事件。该研究将为阐明CRC侵袭转移的分子机制、靶向干预等提供新思路。

DNA methylation of tumor suppressor genes plays an important role in cancers. By using DNA methylation chip and CRISPR-based methylation editing in CRC, we found the "persistent methylation" phenomenon of ANKRD13B gene in the promoter region, which led to the loss of ANKRD13B expression. The promoter region of ANKRD13B has a c-Jun binding site, and methylation level of ANKRD13B increases after overexpression of c-Jun. ANKRD13B could bind to DNA, RNA and METTL3. Overexpression of ANKRD13B reduces the invasiveness and metastasis of tumors, up-regulates the expression of Wnt target genes independing of Wnt signaling pathway activation. Therefore, we propose a scientific hypothesis: c-Jun mediates the "persistent methylation" of ANKRD13B, thus inhibiting the transcription or m6A methylation of Wnt target gene, and then down-regulating the expression of Wnt target gene, promoting the invasion and metastasis of CRC. This project aims to screen the exact mediators in this mechanism by high throughput technology, and further study the upstream and downstream molecular events of ANKRD13B methylation by ChIP, MeRIP, Co-IP, vector construction, CRISPR-based methylation editing and other technologies. This study will provide a scientific basis for elucidating the molecular mechanism of CRC invasion and metastasis, targeting intervention and developing new biomarkers.