Comprehensive and integrative analysis identifies COX7A1 as a critical methylation-driven gene in breast invasive carcinoma

Zhixian He, Feiran Wang, Wei Zhang, Jinhua Ding, Sujie Ni


Background: Aberrant DNA methylation plays a crucial part in cancer progression through the silencing of gene expression. The purpose of this article was to investigate the DNA methylation-driven genes in breast invasive carcinoma (BRCA) by using integrated bioinformatics analysis and in vitro experiments.
Methods: The methylation and expression profile data of BRCA patients were downloaded from the TCGA database. Besides, the MethylMix algorithm was performed to distinguish differentially methylation-driven genes. Moreover, methylation-specific PCR was used to test the methylation-driven genes
Results: A total of 218 differentially expressed methylation-driven genes were obtained. Then, four of these genes were applied to establish a prognostic risk model. Moreover, we found that hypermethylation was in the CpG islands of the promoter of COX7A1 gene in BRCA tissues. Furthermore, we found that COX7A1 was significantly down-regulated BRCA tissues and the COX7A1 expression level was markedly increased in BRCA cells after 5-Aza-dC treatment.
Conclusions: Our study reveals that aberrant promoter hypermethylation is critical for COX7A1 gene silencing in BRCA and that COX7A1 emerge as a new biomarker and therapeutic target for BRCA.