
==== Front
bioRxiv
BIORXIV
bioRxiv
2692-8205
Cold Spring Harbor Laboratory

10.1101/2024.09.09.612036
preprint
1
Article
Estrogen receptor alpha mediated repression of PRICKLE1 destabilizes REST and promotes uterine fibroid pathogenesis
McWilliams Michelle M.
Koohestani Faezeh http://orcid.org/0000-0001-7777-6526

Jefferson Wendy N. http://orcid.org/0000-0002-5741-2159

Gunewardena Sumedha http://orcid.org/0000-0003-2097-135X

Shivashankar Kavya http://orcid.org/0000-0002-2189-3771

Wertenberger Riley A.
Williams Carmen J. http://orcid.org/0000-0001-6440-7086

Rajendra Kumar T. http://orcid.org/0000-0002-7666-5493

Chennathukuzhi Vargheese M. http://orcid.org/0000-0002-4178-146X

09 9 2024
2024.09.09.612036https://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License, which allows reusers to distribute, remix, adapt, and build upon the material in any medium or format, so long as attribution is given to the creator. The license allows for commercial use.
http://biorxiv.org/lookup/doi/10.1101/2024.09.09.612036
nihpp-2024.09.09.612036.pdf
ABSTRACT

Uterine fibroids (leiomyomas), benign tumors of the myometrial smooth muscle layer, are present in over 75% of women, often causing severe pain, menorrhagia and reproductive dysfunction. The molecular pathogenesis of fibroids is poorly understood. We previously showed that the loss of REST ( RE -1 S ilencing T ranscription factor), a tumor suppressor, in fibroids leads to activation of PI3K/AKT-mTOR pathway. We report here a critical link between estrogen receptor alpha (ERα) and the loss of REST, via PRICKLE1. PRICKLE1 expression is markedly lower in leiomyomas, and the suppression of PRICKLE1 significantly down regulates REST protein levels. Conversely, overexpression of PRICKLE1 resulted in the restoration of REST in cultured primary leiomyoma smooth muscle cells (LSMCs). Crucially, mice exposed neonatally to environmental estrogens, proven risk factors for fibroids, expressed lower levels of PRICKLE1 and REST in the myometrium. Using mice that lack either endogenous estrogen ( Lhb -/- mice) or ERα ( Esr1 -/- mice), we demonstrate that Prickle1 expression in the myometrium is suppressed by estrogen through ERα. Enhancer of zeste homolog 2 (EZH2) is known to participate in the repression of specific ERα target genes. Uterine leiomyomas express increased levels of EZH2 that inversely correlate with the expression of PRICKLE1. Using chromatin immunoprecipitation, we provide evidence for association of EZH2 with the PRICKLE1 promoter and for hypermethylation of H3K27 within the regulatory region of PRICKLE1 in leiomyomas. Additionally, siRNA mediated knockdown of EZH2 leads to restoration of PRICKLE1 in LSMCs. Collectively, our results identify a novel link between estrogen exposure and PRICKLE1/REST-regulated tumorigenic pathways in leiomyomas.
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pmc
