(127) Regulatory Role for REST on ESR1 expression in leiomyoma

Skylar G. Bird^1,3, Ashley S. Cloud^1,3, Sornakala Ganeshkumar³, Sumedha Gunewardena², and Vargheese M. Chennathukuzhi^1,3

¹Cell Biology and Physiology and ²Biostatistics. University of Kansas Medical Center, Kansas City, KS 66160. ³Institute for Reproduction and Developmental Sciences, Center for Reproductive Sciences. University of Kansas Medical Center, Kansas City, KS 66160

 

Abstract Text: Uterine fibroids, benign tumors of the smooth muscle layer of the uterus, plague approximately 80% of the female population by age 50. While there have been efforts to understand the mechanism behind this pathophysiology, it largely remains unclear. Lack of preclinical animal models that recapitulate aberrant steroid hormone pathways in UL has significantly hampered the development of long-term hormonal therapies for uterine fibroids. In addition, cultured myometrial cells as well as leiomyoma cells rapidly silence both estrogen receptor and progesterone receptor expression through unknown mechanisms, further limiting drug discovery efforts. Previous work by our lab has determined the loss of REST in leiomyoma results in the upregulation of ESR1 targets and therefore ESR1 signaling. Using ChIP-seq and ChIP-PCR, we find Rest is directly associated with Esr1 genomic locus, playing a role in its epigenetic regulation. We demonstrate the loss of REST leads to upregulation of ESR1 expression in vivo and in cultured myometrial cells. Based on REST’s role in silencing ESR1 expression in cultured myometrial cells, we establish a novel cell culture method to maintain ESR1 expression using siRNA to modulate REST. Additionally, we find REST inhibition of ESR1 is regulated through upstream Wnt planar cell polarity molecule, PRICKLE1. Our results reveal a role for Wnt planar cell polarity in steroid hormone regulation in leiomyoma. We establish a relationship between REST and ESR1 in uterine leiomyoma and establish a critical novel cell culture system to study the development of uterine fibroids.