Abstract 6006: RNA m6A methylation relay the oncogenic flow from DNA methylationto gene expression of ANKRD13B
Authors: Weng JingRong , Lin JinXin , Xie YuMo , Tang GuanNan , Bai LiangLiang , Chen JinHua , Huang ZengHong , Zhuang ZhuoKai , Peng ShaoYong , Wang Heng , Xu GaoPo , Zhang Yu , Liu XiaoXia , Huang MeiJin , Luo YanXin , Wang XiaoLin , Yu Huichuan 
Published: April 2023

Background: Colorectal cancer (CRC) is one of the most common causes of cancer-related death in the world. More comprehensive studies of key molecular alterations in CRC progression were urgent. DNA methylation promotes tumor progression. However, the mechanism of the ANKRD13 gene methylation that drives colorectal cancer evolution remains largely unknown. This was the first study focused on the role of ANKRD13 and the hypermethylated mechanisms in colorectal cancer.

Methods: Chi-Square tests were utilized to the comparison of the baseline characteristics of patients with hypomethylation ANKRD13B and hypermethylated ANKRD13B. Kaplan-Meier analysis were used to estimate the difference of overall survival between the two groups patients. The methylation level of ANKRD13B was quantified by qMSP in colorectal cancer, normal colon epitheliums and colorectal adenoma tissues. CRISPR/dCas9-DNMT3A and CRISPR/dCas9-TET1-CD methylation editing tools were applied to enable targeted and specific CpG methylation at the CpG loci near stop codon of ANKRD13B. Transwell-migrated assay, wound scratch assay and colony formation assay were preformed to ascertain the abilities of viability, migration and invasion in the editing CRC cell lines. The methylated RNA immunoprecipitation (MeRIP) assays, chromatin immunoprecipitation (ChIP) assays and 5-AZA treatment assays were performed combined with qPCR to quantify the m6A levels of ANKRD13B mRNA following hypermethylated-editing.

Results: Here, we identified a novel oncogenic gene, ANKRD13B, encoding ankyrin repeat domain 13B. This gene was frequently hypermethylated in CpG islands surrounding the stop codon region of colorectal cancer. This hypermethylation was associated with poor clinical outcomes in patients diagnosed with colorectal cancer. Compared with normal tissue (4.2%), this type of epigenetic alteration upregulated ANKRD13B expression in both adenoma (73.0%) and adenoma cancer tissues (83.3%) (P&lt; 0.0001), and it also promoted colorectal cancer cell growth, invasion, and migration. Demethylation treatment can reduce the ANKRD13B expression and the growth, migration, and invasion of the cancer cell. Moreover, we found that the aberrant ANKRD13B methylated surrounding the stop codon, and it can promote RNA N6-methyladenosine methylation modification, suggesting that aberrant DNA 5mC methylation promotes ANKRD13B expression and tumor progression in an RNA m6A-dependent manner.

Conclusions: In summary, our findings illustrated that ANKRD13B is an oncogenic gene of colorectal cancer that is commonly methylated and overexpressed in colorectal cancer whose function in the pathogenesis of colorectal cancer depends on RNA m6A-dependent manner. Aberrant DNA 5mC methylation promotes ANKRD13B expression and tumor progression in an RNA m6A-dependent Manner.

Key words: ANKRD13B, DNA methylation, Epigenetic regulation, Colorectal cancer

Citation Format: JingRong Weng, JinXin Lin, YuMo Xie, GuanNan Tang, LiangLiang Bai, JinHua Chen, ZengHong Huang, ZhuoKai Zhuang, ShaoYong Peng, Heng Wang, GaoPo Xu, Yu Zhang, XiaoXia Liu, MeiJin Huang, YanXin Luo, XiaoLin Wang, Huichuan Yu. RNA m6A methylation relay the oncogenic flow from DNA methylationto gene expression of ANKRD13B [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6006.