Biology subjects

Koohestani, F.

Publications and source records attributed to Koohestani, F..

2 recordsLinked to original sources

bioRxiv2024

Estrogen receptor alpha mediated repression of PRICKLE1 destabilizes REST and promotes uterine fibroid pathogenesis

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 Silencing Transcription factor), a tumor suppressor, in fibroids leads to activation of PI3K/AKT-mTOR pathway. We report here a critical link between estrogen receptor alpha (ER) 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 ER (Esr1-/- mice), we demonstrate that Prickle1 expression in the myometrium is suppressed by estrogen through ER. Enhancer of zeste homolog 2 (EZH2) is known to participate in the repression of specific ER 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.

cell biology↗

bioRxiv2022

Loss of the repressor REST affects progesterone receptor function and promotes uterine leiomyoma pathogenesis

Uterine Leiomyomas (UL) are benign tumors that arise in the myometrial layer of the uterus. The standard treatment option for UL is hysterectomy, although hormonal therapies such as selective progesterone receptor modulators are often used as temporary treatment options to reduce symptoms or slow the growth of tumors. However, since the pathogenesis of UL is poorly understood and most hormonal therapies are not based on UL-specific, divergent hormone signaling pathways, hallmarks that predict long-term efficacy and safety of pharmacotherapies remain largely undefined. In a previous study, we reported aberrant expression of REST/NRSF target genes activate UL growth due to the near ubiquitous loss of REST. Here, we show that ablation of the Rest gene in mouse uterus leads to UL phenotype and gene expression patterns analogous to UL, including altered estrogen and progesterone signaling pathways. We demonstrate that many of the genes dysregulated in UL harbor cis-regulatory elements bound by REST and progesterone receptor (PGR) adjacent to each other. Crucially, we identify an interaction between REST and PGR in healthy myometrium and present a putative mechanism for the dysregulation of progesterone responsive genes in UL ensuing the loss of REST. Using three Rest conditional knockout mouse lines, we provide a comprehensive picture of the impact loss of REST has in UL pathogenesis and in altering the response of UL to steroid hormones. Significance statementAblation of Rest gene in the mouse uterus, modelling the loss REST in uterine fibroids, results in tumor formation and gene expression patterns analogous to human UL, including altered estrogen and progesterone receptor (PGR) pathways. The current study provides a putative mechanism for the aberrant function of PGR in UL.

physiology↗