DNA methylation and gene expression in malignant transformation of human bronchial epithelial cells induced by glycidyl methacrylate

The aim of this study was to elucidate the role of DNA methylation-silenced genes in malignant transformation. We screened DNA methylation-silenced genes during methacrylate (GMA)-induced malignant transformation of human bronchial epithelial cells (16HBE) by DNA methylation microarray analysis. The methylation status of some identified genes was assessed by a polymerase chain reaction and compared with uninduced control cells. A total of 801, 66 and 30 genes were silenced in 10th, 20th and 30th generation cells; 8 genes were silenced in 10th and 20th generation cells but not in 30th generation cells; 14 genes were silenced in 30th and 10th generation cells but not in 20th generation cells; and one gene was silenced in 20th and 30th generation cells but not in 10th generation cells. TRPV1 and SOD2 genes were methylated and their gene expression levels were significantly lower in 30th generation 16HBE cells treated with GMA compared to uninduced control cells (P < 0.05). The expression levels of DNA methylation-silenced genes were altered throughout the GMA-induced malignant transformation of 16HBE cells. Furthermore, TRPV1/SOD2 may represent a specific molecular marker associated with the malignant transformation of GMA-stimulated 16HBE cells.