Objective: To determine the expression of miR-29c and its target genes in leiomyoma and the role of NF-κB, specific protein 1 (SP1), and DNA methylation in its regulation.
Design: Experimental study.
Setting: Academic research laboratory.
Patient(s): Women undergoing hysterectomy for leiomyoma.
Intervention(s): Over- and underexpression of miR-29c; blockade of transcription factors.
Main outcome measure(s): MiR-29c and its target gene levels in leiomyoma and the effects of blockade of transcription factors on miR-29c expression.
Result(s): Leiomyoma as compared with myometrium expressed significantly lower levels of miR-29c, with an inverse relationship with expression of its targets, COL3A1 and DNMT3A. Gain of function of miR-29c inhibited the expression of COL3A1 and DNMT3A at protein and mRNA levels, secreted COL3A1, and rate of cell proliferation. Loss of function of miR-29c had the opposite effect. E2, P, and their combination inhibited miR-29c in leiomyoma smooth muscle cells (LSMC). Phosphorylated NF-κB (p65) and SP1 protein expression were significantly increased in leiomyoma. SiRNA knockdown of SP1 and DNMT3A or their specific inhibitors significantly increased the expression of miR-29c, accompanied by the inhibition of cellular and secreted COL3A1 in siRNA-treated cells. Knockdown of p65 also induced miR-29c expression but had no effect on COL3A1 expression.
Conclusion(s): MiR-29c expression is suppressed in leiomyoma, resulting in an increase in expression of its targets COL3A1 and DNMT3A. The suppression of miR-29c in LSMC is primarily mediated by SP1, NF-κB signaling, and epigenetic modification. Collectively, these results indicate a significant role for miR-29c in leiomyoma pathogenesis.
Keywords: COL3A1; DNMT3A; Leiomyoma; SP1; miR-29c.
Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.