Methylation of TP53BP2 and Apaf-1 genes in embryonic lung cells and their impact on gene expression

Background: During embryonic development, epigenetics plays an irreplaceable role in maintaining the normal life activities of mammals. The study of methylation during embryonic lung development will gain a better understanding of the pathogenesis of lung disease. This study aimed to investigate the methylation of promoter-related CpG islands of TP53BP2 and Apaf-1 genes in human embryonic lung cells and their effects on the regulation of gene expression. Methods: The analyses of the methylation-prone region and the relationship with transcription factor binding sites were done by bioinformatic prediction. The bisulfite sequencing PCR was conducted aiming to the target areas. The methylation in promoter area and its impact on transcription factor binding as well as gene expression regulation effect were investigated by methylation inhibitor treatment and real-time PCR detection. Results: Bisulfite sequencing results showed that the CpG methylation predicted by bioinformatic prediction were in part agree with the bisulfite sequencing results, some of the CpG methylation were appeared in the important transcription factor binding sites. After treating with methylation inhibitors, the transcription of Apaf-1 was significantly increased compared with TP53BP2, indicating that partial methylation in proximal promoter of Apaf-1 had a certain effect on transcription Inhibition. Conclusions: The methylation of genes had effect on the growth and development of the embryo in the embryonic lung development, which may be influenced by the combination of key transcription factors, thereby inhibiting the transcriptional expression, ultimately affected the expression and regulation of key genes. These results will help to further understand the epigenetic regulation and its impact on the embryonic development.