Abstract
In this study, our aim was to exploring the influences of DNA methylation of PON1 on cell proliferation, migration and apoptosis of renal cancer cells. The genome-wide methylation array of renal cell carcinoma samples and adjacent tissues were obtained from the cancer genome atlas (TCGA) database. By analysing the DNA methylation and conducting the CpG islands array, methylation status expressed in renal tumour samples and normal renal tissue samples were detected. Methylation-specific PCR (MS-PCR) and qRT-PCR were employed to detect the methylation level and mRNA expression of PON1. Wound-healing assay, transwell assay and MTT assay were utilized to detecting the migration, invasion and proliferation abilities, respectively. The cell apoptosis was testified by Tunnel assay. In addition, the effect of PON1 on renal cancer cells was verified by experiments in vivo. The methylation status of different genes in renal cell carcinoma samples was obtained by CpG islands arrays and hypermethylated PON1 was selected for further study. PON1 was down-regulated in renal cell carcinoma tissues detected by qRT-PCR and Western blot. Both in vitro and vivo experiments indicated that the sunitinib-resistant in renal cancer cells could be suppressed by treat with 5-Aza-dC or TSA, and the effect came out more obvious after 5-Aza-dC and TSA co-treatment. In detail, the demethylation of PON1 inhibited the migration, invasion and proliferation of renal cancer cells and also arrested more cells in G0/G1 phase. The vivo experiment indicated that demethylated PON1 suppressed the growth of tumour. Hypermethylated PON1 promoted migration, invasion and proliferation of sunitinib-resistance renal cancer cells and arrested more cells in G0/G1 phase.