DNA methylation analysis of BeWo cells stimulated by tumor necrosis factor-alpha and insulin-like growth factor-I

Cellular functions of trophoblasts are regulated by various cytokines and growth factors. We previously reported the synergistic effects of tumor necrosis factor-α (TNF-α) and insulin-like growth factor-I (IGF-I) on BeWo cells proliferation. We performed DNA methylation array to elucidate the epigenetic regulation involved in the cross-talk of TNF-α and IGF-I in BeWo cells. We identified general increase in DNA methylation by co-stimulation of TNF-α and IGF-I. Total of 83474 differentially methylated CpG sites were identified in BeWo cells stimulated by IGF-I and high TNF-α. By correlating with the results of expression array, NFKBIE, C3 and GP1BA were identified as differentially methylated genes with significant expression change. Bisulphite converted DNA from 12 samples of BeWo cells were hybridised to Illumina Infinium MethylationEPIC Beadchip