Reducing N6AMT1-mediated 6mA DNA modification promotes breast tumor progression via transcriptional repressing cell cycle inhibitors
Authors: Jinfeng Ning
Ping Wang
Yixuan Zhuang
Wei Liu
Jiongyu Chen
Donghong Zhang
Xueqiong Lin
Yiteng Huang
Lin Peng
Journal: Cell death & disease (2022)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: DNA N6-methyladenosine; epigenetic signaling; breast cancer; N6AMT1; survival
Affiliations: Central Laboratory, Cancer Hospital of Shantou University Medical College, 7 Raoping Road, Shantou, Guangdong, 515041, China., Guangdong Provincial Key Laboratory of Breast Cancer Diagnosis and Treatment, Cancer Hospital of Shantou University Medical College, Shantou, Guangdong, 515041, China., School of Medical Imaging, Tianjin Medical University, Tianjin, 300203, China., Thoracic Department of Harbin Medical University Cancer Hospital, 150 Haping Road, Harbin, 150040, China., Fourth Department of Medical Oncology, Harbin Medical University Cancer Hospital, 150 Haping Road, Harbin, 150040, China., Health Care Center, First Affiliated Hospital of Shantou University Medical College, 52 Southern Dongxia Road, Shantou, Guangdong, 515041, China., Department of Clinical Laboratory, Cancer Hospital of Shantou University Medical College, Shantou, Guangdong, 515041, China., Central Laboratory, Cancer Hospital of Shantou University Medical College, 7 Raoping Road, Shantou, Guangdong, 515041, China. ., Center for Molecular and Translational Medicine, Georgia State University, Research Science Center, 157 Decatur St SE, Atlanta, GA, 30303, USA. .

Abstract:  DNA N6-methyladenosine (6mA) is a novel epigenetic signaling modification in humans and has been implicated in the progression and tumorigenesis of several cancers. However, the function and mechanism of 6mA in breast cancer (BC), the most common cancer among women, are unclear. Here, we found that decreases in N6AMT1 correlated with the extent of 6mA in clinical BC tissues and predicted a worse survival of BC patients. Functionally, knockdown of N6AMT1 markedly reduced 6mA in DNA and promoted colony formation and migration of BC cells, whereas overexpression of N6AMT1 had the opposite effect. Moreover, silencing of N6AMT1 reduced 6mA modification and enhanced the growth of BC cells in vitro and tumors in vivo. 6mA immunoprecipitation sequencing (6mA-IP-seq), RNA-seq, 6mA-IP-PCR, and bioinformatics analysis indicated that N6AMT1 was a functional methyltransferase for genomic 6mA DNA modifications and related to gene transcriptional activity. Critical negative regulators of the cell cycle, such as RB1, P21, REST, and TP53 were identified as targets of N6AMT1 in BC. These results suggest N6AMT1 enhances DNA 6mA levels to repress tumor progression via transcriptional regulation of cell cycle inhibitors. 

Retracted: No

PubPeer comments:
 Recent studies which have carefully re-evaluated existing methodologies for 6mA detection and mapping have shown that there is no evidence for 6mA in mammalian genomes when proper controls are used to eliminate sources of bacterial contamination and other artifacts. In addition, re-examinaton of popular 6mA sequencing methods have revealed severe artifacts in antibody-based approaches like dot blots and MeDIP. Finally, biochemical studies have revealed that N6Amt1 functions as a protein methyltransferase (NOT a DNA methyltransferase). Please see the following: No Evidence for 6mA in mammals and other metazoa: https: www.ncbi.nlm.nih.gov labs pmc articles PMC7080441 https: bmcgenomics.biomedcentral.com articles 10.1186 s12864-019-5754-6 https: pubmed.ncbi.nlm.nih.gov 28371147 N6Amt1 is a protein methyltransferase DOES NOT methylate DNA https: pubmed.ncbi.nlm.nih.gov 31636962 ,