Gonadotropin-releasing hormone agonist increases expression of osmotic response genes in leiomyoma cells

Abstract

Objective To characterize hyperosmolarity-responsive genes in leiomyoma cells and determine whether gonadotropin-releasing hormone (GnRH) agonist treatment altered their expression. Design Laboratory study. Setting University hospital. Patient(s) None. Intervention(s) Cell culture under hypertonic conditions and with GnRH agonist treatment, RNA isolation, and real-time reverse-transcriptase polymerase chain reaction (RT-PCR). Main Outcome Measure(s) Expression of nuclear factor of activated T cells 5 (NFAT5), aldose reductase (AR), and sodium myo-inositol transporter 1 (SMIT) messenger RNA (mRNA) in immortalized leiomyoma and patient-matched myometrial cells. Result(s) Leiomyoma cells had increased basal expression of NFAT5 mRNA (1.7 ± 0.08-fold) compared with myometrial cells. The NFAT5 increased further in leiomyoma cells cultured under hyperosmolar conditions (3.0 ± 0.46-fold at 50 mM NaCl and 3.3 ± 0.48-fold at 100 mM NaCl). The NFAT5-regulated mRNA transcripts for AR and SMIT were increased in untreated leiomyoma cells compared with myometrial cells and further increased in leiomyoma cells exposed to osmotic stress. The NFAT5 transcripts were decreased with low-dose GnRH agonist treatment but increased with supraphysiologic doses. Conclusion(s) Expression of hyperosmolarity genes was increased in leiomyoma cells relative to myometrial cells. Pharmacologic concentrations of GnRH agonist decreased NFAT5 expression, suggesting that water flows out of leiomyoma cells at pharmacologic doses.

Gonadotropin-releasing hormone analogues inhibit leiomyoma extracellular matrix despite presence of gonadal hormones

“…We have previously demonstrated, in 2D leiomyoma cultures, that GnRH-a have a direct effect on tumor ECM production (19) and osmoregularity (20). The effect on ECM production was not observed until 120 hours of GnRH-a exposure.…”

“…The presence of receptors for GnRH hormones in leiomyomas is further evidenced by the direct regulation of GnRH analogues (GnRH-a) on leiomyoma cell ECM gene expression and protein production in culture (19). The GnRH agonist leuprolide acetate (LA) regulates cellular osmolarity and water transport out of leiomyoma cells grown in culture (20). Clinically, the use of GnRH-a as a part of an adjunct presurgical approach to reduce the size of leiomyomas and increase hematocrit in affected patients has been reported (21).…”

NFAT5 promotes proliferation and migration of lung adenocarcinoma cells in part through regulating AQP5 expression

“…Recent researches showed that NFAT5 is involved in the pathogenesis of multiple cancers including non-small cell lung cancer [24,25], melanoma [26], leiomyoma [27], breast cancer [28e30] and colon carcinoma [31e33]. In non-small cell lung cancer, NFAT5 inhibits cancer cells apoptosis by upregulating HSP-70 [25], but the roles of NFAT5 in proliferation, metastasis and invasion of lung cancer cells have not been stated.…”

Characterization of tissue biomechanics and mechanical signaling in uterine leiomyoma

“…Of note, leiomyomata possess an increased vascularity and fluid content relative to adjacent myometrium (Aleem and Predanic, 1995; Okuda et al, 2008). The increased fluid content is significant because fluid may contribute to the mechanical properties of the tumors and may explain the clinical response of leiomyoma to GnRH agonists and antagonist treatment (Chegini et al, 1996; McCarthy-Keith et al, 2011). Despite the remarkable stiffness of leiomyomata, their altered ECM structure and content, and increased water content, little is known about mechanical signaling in leiomyoma.…”

“…Furthermore, we found that the Rho-GEF Brx (AKAP13) was not only expressed at high levels in leiomyoma (Rogers et al, 2008), but AKAP13 was also involved in osmotic signaling (Kino et al, 2009) and osmotic signaling was altered in leiomyoma cells (McCarthy-Keith et al, 2011). Taken together, these observations suggest that altered mechanical signaling in leiomyoma involves RhoA and that altered viscoelastic properties contribute significantly to the increased stiffness characteristic of the tumors.…”