Fig. 4.

IGF-1 upregulated DNMTs via the PI3K/AKT pathway. a qPCR analysis of DNA methyltransferase (DNMT)1, DNMT3α, and DNMT3β expression in CSCs treated with PBS or 100 ng/ml insulin-like growth factor-1 (IGF-1) for 72 h, pretreated with 50 μM LY294002 for 30 min and then stimulated with 100 ng/ml IGF-1 for 72 h or treated with 50 μM LY294002. GAPDH expression was measured as a control (CON). The data were obtained from at least three independent experiments and are expressed as the mean ± SD. b Western blot analysis of DNMT1, DNMT3α, and DNMT3β expression in CSCs treated as described above. GAPDH expression was measured as a control. c CSCs were divided into four groups: normal control (CON), 100 ng/ml IGF-1 for 72 h, 1 μM 5-azacytidine (5-AZA) for 72 h, and both IGF-1 and 5-AZA. Western blots were performed to analyze the expression of the c-kit protein. q-PCR analysis of c-kit expression. The data were obtained from three independent experiments and expressed as the mean ± SD; n = 3. *P < 0.05, between groups indicated. NS not significant