Transcription factor FOXM1 plays a critical role in maintenance of stem cell pluripotency through stimulating the transcription of pluripotency-related genes in mouse pluripotent stem cells. In this study, we have found that the repression of FOXM1 expression is mediated by FOXM1 3'UTR during retinoic acid-induced differentiation of human pluripotent NT2/D1 embryonal carcinoma cells. FOXM1 3'UTR contains a microRNA response element (MRE) for miR-134, which has been shown to attenuate the expression of pluripotency-related genes post-transcriptionally during mouse embryonic stem cell differentiation. We have determined that miR-134 is induced during RA-induced differentiation of NT2/D1 cells and the overexpression of miR-134 represses the expression of FOXM1 protein but not FOXM1 mRNA. Furthermore, the expression of OCT4 is diminished by FOXM1 knockdown and the OCT4 promoter is regulated directly by FOXM1, suggesting that FOXM1 is required for maintaining the expression of OCT4 in NT2/D1 cells. Together, our results suggest that FOXM1 is essential for human pluripotent stem cells and miR-134 attenuates its expression during differentiation.
Keywords: FOXM1 transcription factor; Pluripotent NT2/D1 embryonal carcinoma (EC) cells; Retinoic acid-induced differentiation; miR-134.
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