Proliferation Of Uterine Leiomyoma Cells Research Articles

Effects ofCallicarpa nudifloraGranules on the Proliferation and Apoptosis of Uterine Fibroid Cells

This research was aimed to discuss and understand the effects and mechanisms of action ofCallicarpa nudifloragranules on proliferation and apoptosis of uterine leiomyoma (UL) cells. Firstly, normal uterine myometrium (UM) and UL tissues were collected, and the levels of p-Akt and Phosphatase and Tensin Homolog (PTEN) in UL tissues were detected using immunohistochemistry. Next, the UL cells were successfully obtained using enzymatic digestion, and their identification was performed using alpha-smooth muscle actin (α-actin) immunocytochemistry. Specifically, the cells were grouped into four: a control group (CG), a low-dose group (LDG, 50 mg/LCallicarpa nudiflorasolution), a medium-dose group (MDG, 100 mg/LCallicarpa nudiflorasolution), and a high-dose group (HDG, 200 mg/LCallicarpa nudiflorasolution). Moreover, the proliferation of UL cells was assessed using the thiazolyl blue (MTT) assay, while cell apoptosis was analyzed using flow cytometry (FCT). Real-time fluorescent quantitative PCR (fq-PCR) and Western blot assay (WBA) were utilized to determine the PAI-1, P38, TGF-β1, E-cadherin, and Vimentin in UL cells. The results revealed that the positive rate (PR) of p-Akt in the UL tissues was much higher to that in normal UM tissues (P< 0.001). More than 90% of UL cells were positive forα-actin. The viabilities of UL cells in theCallicarpa nudifloratreatment groups were greatly weakened to that of untreated cells (P< 0.05). Viability of UL cells in the HDG group was the lowest, showing a great difference withP< 0.01 to the LDG group and that withP< 0.05 to the MDG group, while that between the MDG and LDG groups exhibited a great difference withP< 0.05. AR of UL cells in CG group was sharply lower to that in theCallicarpa nudifloratreatment groups, showing great differences withP< 0.05,P< 0.01, andP< 0.001, respectively. AR of UL cells in HDG group was higher to the LDG group (P< 0.01) and MDG group (P< 0.05), and that in LDG group was lower and exhibited a great difference withP< 0.05 to the MDG group. The HDG, LDG, and MDG groups exhibited greatly lower TGF-β1, PAI-1, and P38 to the CG group (P< 0.05). In the HDG group, the TGF-β1, PAI-1, P38, and Vimentin levels were greatly lower and presented a great difference withP< 0.01 to those in the CG group and LDG group. Additionally, E-cadherin in UL cells was elevated in the LDG and MDG groups to CG group, showingP< 0.05 andP< 0.01, respectively. Such findings indicated that theCallicarpa nudifloragranules can suppress proliferation of UL cells and promote their apoptosis, which may be associated with the TGF-β1/P38/PAI-1 singling pathway (SPW).

Oxidative stress mediates the inhibitory effects of Manzamine A on uterine leiomyoma cell proliferation and extracellular matrix deposition via SOAT inhibition

Uterine fibroids, the most common benign tumors of the myometrium in women, are characterized by abnormal extracellular matrix deposition and uterine smooth muscle cell neoplasia, with high recurrence rates. Here, we investigated the potential of the marine natural product manzamine A (Manz A), which has potent anti-cancer effects, as a treatment for uterine fibroids. Manz A inhibited leiomyoma cell proliferation in vitro and in vivo by arresting cell cycle progression and inducing caspase-mediated apoptosis. We performed target prediction analysis and identified sterol o-acyltransferases (SOATs) as potential targets of Manz A. Cholesterol esterification and lipid droplet formation were reduced by Manz A, in line with reduced SOAT expression. As a downstream target of SOAT, Manz A also prevented extracellular matrix deposition by inhibiting the β-catenin/fibronectin/metalloproteinases axis and enhanced autophagy turnover. Excessive free fatty acid accumulation by SOAT inhibition led to reactive oxygen species to impair mitochondrial oxidative phosphorylation and trigger endoplasmic reticulum stress via PERK/eIF2α/CHOP signaling. The inhibitory effect of ManzA on cell proliferation was partially restored by PERK knockdown and eliminated by tauroursodeoxycholic acid, suggesting oxidative stress plays a critical role in the mechanism of action of Manz A. These findings suggest that targeting SOATs by Manz A may be a promising therapeutic approach for uterine fibroids.

MiR-139-5p Regulates Proliferation, Apoptosis, and Cell Cycle of Uterine Leiomyoma Cells by Targeting TPD52 [Retraction

[This retracts the article DOI: 10.2147/OTT.S108890.].

Insulin-Like Growth Factor-1 Promotes Human Uterine Leiomyoma Cell Proliferation via PI3K/AKT/mTOR Pathway

The present research aimed to evaluate the expression of insulin-like growth factor-1 (IGF-1) in uterine leiomyoma, and explore its relationship with the occurrence and development of uterine leiomyoma and potential signal pathways. qRT-PCR and enzyme-linked immunosorbent assay were used for estimating the levels of IGF-1 in human uterine leiomyoma compared to myometrium. The expression of cell proliferation and PI3K/AKT/mTOR signaling pathway-related proteins in uterine leiomyoma cells was evaluated by western blot. Cell viability analysis was performed by CCK-8 assay. Lentivirus infection was used for IGF-1 overexpression and knockdown in uterine leiomyoma cells. The IGF-1 expression level was elevated in human uterine leiomyomas compared to myometrium. IGF-1 promoted the cell viability of human uterine leiomyoma cells. Overexpression of IGF-1 induced the expression of pro-proliferation markers including c-Myc, PCNA, and cyclin D1 in uterine leiomyoma cells. IGF-1 elevated the phosphorylation levels of PI3K, AKT, and mTOR, thus modifying PI3K/AKT/mTOR signaling in uterine leiomyoma cells. IGF-1 promotes proliferation of human uterine leiomyoma cells via PI3K/AKT/mTOR pathway.

Inhibiting effect of miR-29 on proliferation and migration of uterine leiomyoma via the STAT3 signaling pathway.

Aim: Uterine leiomyoma is the most common benign tumor of female genitalia, and the incidence is rising gradually. This study explores the mechanism of miR-29 and STAT3 signaling pathways on uterine leiomyoma.Methods: GSE64763 and GSE5244 datasets were downloaded. Enrichment analyses were performed in GSE64763. PPI network was constructed, and the significant module was identified. Uterine leiomyoma cell lines were divided into NC, miR-29 mimic, anti-NC, and miR-29 inhibitor groups. Plate clone formation and Transwell assays detected the proliferation, invasion, and migration of cells. The expression levels of STAT3, proliferation, EMT, invasion-associated proteins were determined by Western blotting.Results: Differently expressed genes were mainly enriched in positive regulation of cell migration and gene expression, cell proliferation. Through GSEA, JAK-STAT is a significantly correlated enrichment pathway. A Venn diagram was drawn to identify the common miRNA (miR-29-3p). miR-29 inhibitors promoted protein expression of STAT-3, Cyclin D1, and c-Myc compared with the anti-NC control (P < 0.01), and miR-29 inhibitors promoted cell proliferation in uterine leiomyoma cells (P < 0.05). Furthermore, miR-29 inhibitors promoted the protein expression of MMP-2 and MMP-9 (P < 0.01), and EMT promoting proteins N-cadherin, snail, vimentin, and Transwell assay showed that miR-29 inhibitors promoted cell migration in uterine leiomyoma (P < 0.01).Conclusions: High expression of miR-29 could inhibit cell proliferation, invasion, and metastasis in uterine leiomyoma, which might be related to the inhibition of the STAT3 signaling pathway, and could provide a novel target for the treatment of uterine leiomyoma.

\u201cMetalloestrogenic\u201d effects of cadmium downstream of G protein-coupled estrogen receptor and mitogen-activated protein kinase pathways in human uterine fibroid cells

Cadmium (Cd) is a toxic metal reported to act as an estrogen “mimic” in the rat uterus and in vitro. We have reported that Cd stimulates proliferation of estrogen-responsive human uterine leiomyoma (ht-UtLM; fibroid) cells through nongenomic signaling involving the G protein-coupled estrogen receptor (GPER), with activation of epidermal growth factor receptor (EGFR) and mitogen-activated protein kinase (pMAPK44/42). In this study, we explored Cd-induced mechanisms downstream of MAPK and whether Cd could stimulate phosphorylation of Histone H3 at serine 10 (H3Ser10ph) through activated Aurora B kinase (pAurora B), a kinase important in activation of histone H3 at serine 10 during mitosis, and if this occurs via Fork head box M1 (FOXM1) and cyclin D1 immediately downstream of MAPK. We found that Cd increased proliferating cell nuclear antigen (PCNA) and H3Ser10ph expression by immunofluorescence, and that H3ser10ph and pAurora B were coexpressed along the metaphase plate in ht-UtLM cells. In addition, Cd-exposed cells showed higher expression of pMAPK44/42, FOXM1, pAurora B, H3ser10ph, and Cyclin D1 by western blotting. Immunoprecipitation and proximity ligation assays further indicated an association between FOXM1 and Cyclin D1 in Cd-exposed cells. These effects were attenuated by MAPK kinase (MEK1/2) inhibitor. In summary, Cd-induced proliferation of ht-UtLM cells occurred through activation of Histone H3 and Aurora B via FOXM1/Cyclin D1 interactions downstream of MAPK. This provides a molecular mechanism of how Cd acts as an “estrogen mimic” resulting in mitosis in hormonally responsive cells.

LncRNA APTR Promotes Uterine Leiomyoma Cell Proliferation by Targeting ERα to Activate the Wnt/β-Catenin Pathway.

The molecular mechanisms by which uterine leiomyoma (UL) cells proliferate are unclear. Long noncoding RNA (lncRNA) is reported to participate in the occurrence and development of gynecological cancers. We investigated the molecular mechanisms that lncRNA uses in UL. We found that lncRNA Alu-mediated p21 transcriptional regulator (APTR) showed higher expression in UL tumor tissues compared with that in normal uterine tissues. APTR induced cell proliferation and colony formation both in vitro and in vivo. The JASPAR database showed that APTR was likely interacted with ERα, and these molecules were identified via laser scanning confocal microscopy and RNA immunoprecipitation analysis. To verify the correlation between APTR and ERα, we overexpressed and underexpressed APTR and simultaneously expressed ERα. The results showed that APTR function was suppressed. APTR increased the expressions of the proteins in the Wnt pathway, and inhibiting ERα eliminated these responses. In conclusion, our data suggest that APTR promoted leiomyoma cell proliferation through the Wnt pathway by targeting ERα, suggesting a new role of APTR in the Wnt signaling pathway in UL.

The function role and synergic effect of syndecan-1 for mifepristone in uterine leiomyoma

The study intends to investigate the regulation of syndecan-1 in human uterine leiomyoma cells. Human syndecan-1 levels were detected by Western blot in uterus leimyoma's tissue. The efficacy of syndecan-1 silencing on the cell proliferation, metalloproteinases and extracellular matrix were determined through Cell Counting Kit (CCK8) assay and Western blot assay, respectively. We compared the respective and combined effect of mifepristone and syndecan-1 on cell proliferation and the expression of metalloproteinases and extracellular matrix (ECM) in human uterine leiomyoma cells. The inhibitory effects of Syndecan-1 silencing on proliferation, ECM and Matrix Metalloproteinase (MMP) were observed in human uterine leiomyoma cells. Furthermore, syndecan-1 inhibition enhanced the effects of mifepristone against uterine leiomyoma cell proliferation. The expression of MMPs and ECM components in human uterine leiomyoma cells was decreased dramatically after syndecan-1 silencing, which was promoted after mifepristone treatment. Altogether, syndecan-1 silencing enhanced the efficacy of mifepristone on the uterine leiomyoma cell proliferation and ECM formation. Therefore, targeting syndecan-1 represents a novel therapeutic strategy to treat uterine leiomyoma.

The influence of phenolic environmental estrogen on the transcriptome of uterine leiomyoma cells: A whole transcriptome profiling-based analysis

ObjectiveThe study aimed to recognize potential molecular targets and signal pathways whereby phenolic environmental estrogen promotes the proliferation of uterine leiomyoma cells. MethodsPrimary cultured cell lines of uterine leiomyoma were treated with 0.1% DMSO, 10.0μmol/L Bisphenol A (BPA), and 32.0μmol/L Nonylphenol (NP) for 48 h before RNA-seq was performed. Those genes affected by BPA and NP were identified. Then, Gene Ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, and Protein-protein Interaction (PPI) analysis were performed. Quantitative real-time polymerase chain reaction (q-PCR) and western blot were used to verify the differentially expressed gene and protein. ResultsCompared to with the control group, 739 differentially expressed genes were identified in both the BPA group and the NP group. GO enrichment analysis showed that the most enriched GO terms were connective tissue development and G1/S transition of mitotic cell cycle, and extracellular matrix. The results of KEGG enrichment analysis showed that differentially expressed mRNA were enriched mainly in three primary pathways, including environmental information processing, human diseases, and cellular processes. The cell cycle, PI3K-Akt signaling pathway are significantly enriched. The q-PCR and western blot verified the cell cycle associated genes and proteins were upregulated in both BPA group and NP group. Both BPA and NP activated the PI3K-AKT signaling pathway. ConclusionPhenolic environmental estrogens may promote the proliferation and cell cycle progression of uterine leiomyoma cells through rapid non-genomic ER signaling, which leads to disordered cell cycle regulation and accelerates the transition of the cell cycle from G0/G1 phase to S phase. In addition, as an external stimulant, phenolic estrogen promotes the upregulation of inflammatory factors in uterine leiomyomas.

Selective estrogen receptor modulator with estrogen does not affect the proliferation and apoptosis of uterine leiomyoma cells.

BackgroundThe administration of menopausal hormone therapy (MHT) in women with uterine leiomyomas is still debated. The purpose of this article is to study the proliferation and apoptosis of uterine leiomyoma cells under the impact of selective estrogen receptor modulator (SERM) combined with estrogen.MethodsPrimary cultured uterine leiomyoma cells in the perimenopausal period were treated with estrogen (17-beta estradiol) + SERM (raloxifene) as the tissue selective estrogen complex (TSEC) group, while both estrogen + medroxyprogesterone acetate (E+P) and estrogen (E) alone as were used as control groups. The expression of proliferating cell nuclear antigen (PCNA) and B-cell lymphoma-2 (Bcl-2) proteins was assessed by methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay and western-blot analysis, respectively.ResultsThe proliferation in the TSEC group was weaker than the control groups (P<0.001). There was no statistical difference between the TSEC and blank control group on cell proliferation at 72 h (P=0.13). However, there was a significant difference between the other groups (P<0.001). PCNA expression of TSEC was lower than that of the E + P and E groups (P<0.05). There was no statistical difference in the expression of PCNA between the TSEC and blank control groups (P=0.63). Bcl-2 expression of TSEC was lower than that of the E + P and E groups (P<0.05). There was no statistical difference in the expression of Bcl-2 between the TSEC group and the blank control group (P=0.60).ConclusionsSERM combined with estrogen may have a better safety for perimenopausal women with uterine leiomyoma in MHT.

TRIM9 overexpression promotes uterine leiomyoma cell proliferation and inhibits cell apoptosis via NF-κB signaling pathway

AimsUterine leiomyoma (UM) is the most common benign gynecological tumor and the leading indication for hysterectomy. Our study explored the roles of TRIM9 in leiomyoma formation and investigated the underlying molecular mechanisms. Material and methodsThe relationship between TRIM9 expression and fibroids formation was deciphered from the GEO database after bioinformatics analysis and identified by qPCR in human leiomyoma tissues. Both TRIM9 mRNA and protein expression were further detected in primary cultured uterine leiomyoma cells (UMC). The tumorigenesis potentials of TRIM9 in cell proliferation, cell cycle, cell apoptosis; cyclin D1, survivin and cleaved-caspase 3 protein expressions in primary UMC with TRIM9 overexpression (UMC-oeTRIM9); and uterine smooth muscle cells (SMC) with TRIM9 knockdown (SMC-siTRIM9) were evaluated in vitro. NF-κB p65 and its phosphorylation were further examined by western blotting, and rescue experiments on cell proliferation, cell cycle and cell apoptosis were conducted. Key findingsTRIM9 showed higher expression in UM tissue and UMC compared with normal myometrium. The overexpression of TRIM9 in UMC notably promoted UM growth via enhancement of cell proliferation, reduction of cell apoptosis, and regulation of cyclin D1, survivin, cleaved-caspase 3, and nuclear NF-κB expression, which were reversed in SMC-siTRIM9 and PDTC (an NF-κB inhibitor) intervention in UMC-oeTRIM9. SignificanceTo our knowledge, this was the first study demonstrating the roles of TRIM9 in cell growth progression of UM development. TRIM9 may be a potential therapeutic target for UM, by promoting leiomyoma cell proliferation and reducing cell apoptosis via activation of the NF-κB pathway.

MiR-139-5p Regulates Proliferation, Apoptosis, and Cell Cycle of Uterine Leiomyoma Cells by Targeting TPD52 [Expression of Concern

miR-139-5p Regulates Proliferation, Apoptosis, and Cell Cycle of Uterine Leiomyoma Cells by Targeting TPD52 [Expression of Concern

Melatonin activates cell death programs for the suppression of uterine leiomyoma cell proliferation.

The circadian nature of melatonin has a protective effect on the progression of female reproductive cancers, including breast and ovarian cancers. However, the effect of melatonin on the growth of uterine leiomyoma is still unclear. In this study, we found that the growth of uterine leiomyoma ELT3 cells was reduced by treatment with melatonin. Treatment with melatonin increased the distribution of sub-G1 phase and increased DNA condensation in ELT3 cells. Melatonin-induced apoptosis and autophagy cell death progression were observed in ELT3 cells. Melatonin exerts a highly selective effect on primary normal human uterine smooth muscle (UtSMC) cells. The UtSMC cell cycle was arrested by melatonin treatment through up-regulation of p21, p27, and PTEN protein expression, but melatonin did not further promote apoptosis program activation. Melatonin reduced cell proliferation in ELT3 cells underlying the activation of melatonin MT1 and MT2 receptors, which in turn down-regulated the Akt-ERK1/2-NFκB signaling pathway. Melatonin reduced ELT3 tumor growth in both xenograft and orthotopic uterine tumor mice models. The extracellular matrix of the tumor was also reduced by melatonin treatment. Taken together, these results suggest that melatonin potentially plays a role in suppression of uterine leiomyoma growth.

Effects of progesterone receptor on proliferation of uterine leiomyoma cells.

In order to study the mechanism of the effect of progesterone receptor on the growth of primary uterine leiomyoma cells, the primary cells were extracted from uterine leiomyoma cells and identified by immunohistochemistry (IHC). Mitochondrial progesterone receptor-positive [PR-M(+)], mitochondrial progesterone receptor-negative [PR-M(-)], progesterone receptor A (PR-A) and progesterone receptor B (PR-B) were screened by Western blotting. Different concentrations of Mifepristone (MIF), a progesterone receptor antagonist, were used to interfere with PR-M(+) and PR-M(-) cell lines, respectively. Proliferation and apoptosis of PR-M(+) and PR-M(-) cell lines were detected by tetramethylazolyl blue method and flow cytometry, respectively. The expression of Caspase-3 and B-cell lymphoma 2 (Bcl-2) protein was detected by Western blotting. The results showed that the growth of PR-M(+) and PR-M(-) uterine leiomyoma cells was inhibited with the increase of MIF concentration. Furthermore, the proliferation inhibition rate and apoptosis rate were gradually increased. However, the expression of Caspase-3 protein on progesterone receptor M increased, while the expression of Bcl-2 decreased. Moreover, progesterone could induce progesterone receptor M to up-regulate apoptotic protein Caspase-3 and down-regulate anti-apoptotic protein Bcl-2, thus it could inhibit the apoptosis of primary cultured uterine leiomyoma cells and promote the proliferation of leiomyoma cells.

A nongenomic mechanism for "metalloestrogenic" effects of cadmium in human uterine leiomyoma cells through G protein-coupled estrogen receptor.

Cadmium (Cd) is a ubiquitous environmental metal that is reported to be a "metalloestrogen." Uterine leiomyomas (fibroids) are estrogen-responsive gynecologic neoplasms that can be the target of xenoestrogens. Previous epidemiology studies have suggested Cd may be associated with fibroids. We have shown that Cd can stimulate proliferation of human uterine leiomyoma (ht-UtLM) cells, but not through classical estrogen receptor (ER) binding. Whether nongenomic ER pathways are involved in Cd-induced proliferation is unknown. In the present study, by evaluating G protein-coupled estrogen receptor (GPER), ERα36, and phospho-epidermal growth factor receptor (EGFR) expression in human tissues, we found that GPER, ERα36 and phospho-EGFR wereallhighly expressed in fibroids compared to patient-matched myometrial tissues. In ht-UtLM cells, cell proliferation was increased by low doses of Cd (0.1µM and 10µM), and this effect could be inhibited by GPER-specific antagonist (G15) pretreatment, or silencing (si) GPER, but not by siERα36. Cd-activated MAPK was dependent on GPER/EGFR transactivation, through significantly increased phospho-Src, matrix metalloproteinase-2 (MMP2) and MMP9, and heparin-binding EGF-like growth factor (HB-EGF) expression/activation. Also, phospho-Src could interact directly to phosphorylate EGFR. Overall, Cd-induced proliferation of human fibroid cells was through a nongenomic GPER/p-src/EGFR/MAPK signaling pathway that did not directly involve ERα36. This suggests that Cd may be a risk factor for uterine fibroids through cross talk between hormone and growth factor receptorpathways.

Effects of progesterone receptor on proliferation of uterine leiomyoma cells.

In order to study the mechanism of the effect of progesterone receptor on the growth of primary uterine leiomyoma cells, the primary cells were extracted from uterine leiomyoma cells and identified by immunohistochemistry (IHC). Mitochondrial progesterone receptor-positive [PR-M(+)], mitochondrial progesterone receptor-negative [PR-M(-)], progesterone receptor A (PR-A) and progesterone receptor B (PR-B) were screened by Western blotting. Different concentrations of Mifepristone (MIF), a progesterone receptor antagonist, were used to interfere with PR-M(+) and PR-M(-) cell lines, respectively. Proliferation and apoptosis of PR-M(+) and PR-M(-) cell lines were detected by tetramethylazolyl blue method and flow cytometry, respectively. The expression of Caspase-3 and B-cell lymphoma 2 (Bcl-2) protein was detected by Western blotting. The results showed that the growth of PR-M(+) and PR-M(-) uterine leiomyoma cells was inhibited with the increase of MIF concentration. Furthermore, the proliferation inhibition rate and apoptosis rate were gradually increased. However, the expression of Caspase-3 protein on progesterone receptor M increased, while the expression of Bcl-2 decreased. Moreover, progesterone could induce progesterone receptor M to up-regulate apoptotic protein Caspase-3 and down-regulate anti-apoptotic protein Bcl-2, thus it could inhibit the apoptosis of primary cultured uterine leiomyoma cells and promote the proliferation of leiomyoma cells.

Bisphenol A induces human uterine leiomyoma cell proliferation through membrane-associated ERα36 via nongenomic signaling pathways

The role of ERα36 in regulating BPA's effects and its potential as a risk factor for human uterine fibroids were evaluated. BPA at low concentrations (10−6 μM - 10 μM) increased proliferation by facilitating progression of hormonally regulated, immortalized human uterine leiomyoma (ht-UtLM; fibroid) cells from G0-G1 into S phase of the cell cycle; whereas, higher concentrations (100 μM–200 μM) decreased growth. BPA upregulated ERα36 gene and protein expression, and induced increased SOS1 and Grb2 protein expression, both of which are mediators of the MAPKp44/42/ERK1/2 pathway. EGFR (pEGFR), Ras, and MAPKp44/42 were phosphorylated with concurrent Src activation in ht-UtLM cells within 10 min of BPA exposure. BPA enhanced colocalization of phosphorylated Src (pSrc) to ERα36 and coimmunoprecipitation of pSrc with pEGFR. Silencing ERα36 with siERα36 abolished the above effects. BPA induced proliferation in ht-UtLM cells through membrane-associated ERα36 with activation of Src, EGFR, Ras, and MAPK nongenomic signaling pathways.

Progesterone receptor integrates the effects of mutated MED12 and altered DNA methylation to stimulate RANKL expression and stem cell proliferation in uterine leiomyoma

Progesterone and its receptor, PR, are essential for uterine leiomyoma (LM, a.k.a., fibroid) tumorigenesis, but the underlying cellular and molecular mechanisms remain unclear. The receptor activator of NF-κB (RANKL) was recently identified as a novel progesterone/PR-responsive gene that plays an important role in promoting LM growth. Here, we used RANKL as a representative gene to investigate how steroid hormone, genetic, and epigenetic signals are integrated to regulate LM stem cell (LSC) function. We demonstrated that RANKL specifically upregulates LSC proliferation through activation of Cyclin D1. RANKL gene transcription was robustly induced by the progesterone agonist R5020, leading to a dramatically higher RANKL expression in LM compared to adjacent myometrial (MM) tissue. MethylCap-Seq revealed a differentially methylated region (DMR) adjacent to the distal PR-binding site (PRBS) 87 kb upstream of the RANKL transcription start site. Hypermethylation of the DMR inhibited recruitment of PR to the adjacent PRBS. Luciferase assays indicated that the DMR and distal PRBS constitute a novel RANKL distal regulatory element that actively regulates RANKL expression. Furthermore, MED12 physically interacts with PR in LM tissue. The interaction between MED12 and PR, binding of PR and MED12 to PRBS, and RANKL gene expression are significantly higher in LM containing a distinct MED12 mutation (G44D) than in LM with wild-type MED12. In summary, our findings suggest that DNA methylation and MED12 mutation together constitute a complex regulatory network that affects progesterone/PR-mediated RANKL gene expression, with an important role in activating stem cell proliferation and fibroid tumor development.

Ulipristal acetate regulates perilipin-2 gene expression through progesterone receptor isoform B in uterine leiomyoma cells

Progesterone and its receptor (PR) exert a tumorigenic effect on leiomyoma cells. There are two functionally distinct isoforms of PR: PRA and PRB. Ulipristal acetate (UPA), a selective PR modulator, has been clinically shown to reduce the size of leiomyomas, although the exact mechanisms are unknown. Using an unbiased ChIP-sequencing technique, we previously uncovered perilipin-2 (PLIN2) as a novel PR target gene in primary human uterine leiomyoma cells. PLIN2, an adipose differentiation-related protein, is a cytoplasmic lipid droplet binding protein that plays an important role in lipid metabolism. PLIN2 has been shown to mediate cell proliferation, apoptosis, and fibrogenic gene expression in various cell types such as pancreatic and hepatic stellate cells; however, little is known about the role of PLIN2 in the regulation of the growth of human uterine leiomyomas. The present study aimed to test whether UPA regulates PLIN2 expression and to determine the function of PLIN2 in leiomyoma cells. Basic science. Myometrial and leiomyoma tissues were collected from premenopausal women undergoing hysterectomies. We examined the impact of UPA treatment on PLIN2 gene expression and its function in leiomyoma cells by depleting PLIN2 and PR expression via small interfering RNA (siRNA). We also characterized the PLIN2 gene expression patterns between leiomyoma and matched myometrial tissues. We found that 75% of subjects’ leiomyoma tissue expressed lower mRNA levels of PLIN2 compared to the adjacent myometrial tissue. We also found that UPA treatment induced PLIN2 expression in a time and dose-dependent manner in primary leiomyoma cells. When we knocked down PR to determine whether ulipristal treatment induced PLIN2 expression through PR, we found that PR siRNA dramatically decreased the total PR level to 20%; however, it only mildly decreased PRB expression (80% of control level), suggesting that PR siRNA may disproportionately deplete endogenous PRA more efficiently than PRB. Intriguingly, UPA treatment consistently stimulated PLIN2 expression in the control (scrambled) siRNA group. PLIN2 expression was further increased in the PR siRNA group, suggesting that UPA upregulated PLIN2 expression predominantly through PRB and that PRA may function to inhibit PRB-mediated PLIN2 transcriptional activity. Furthermore, knockdown of PLIN2 with siRNA significantly increased protein levels of proliferating cell nuclear antigen (a marker for cell proliferation). We present evidence that UPA stimulates PLIN2 expression and PLIN2 represses cell proliferation in primary uterine leiomyoma. Our findings also suggest that PRA and PRB may play differential roles in leiomyoma growth. We speculate that PLIN2 plays an important role in mediating the therapeutic effects of ulipristal in uterine leiomyomas.

Berberine Inhibits Uterine Leiomyoma Cell Proliferation via Downregulation of Cyclooxygenase 2 and Pituitary Tumor-Transforming Gene 1.

We previously demonstrated that berberine (BBR) inhibits cell proliferation and induces apoptosis in a human uterine leiomyoma (UtLM) cell line but does not demonstrate a significant cytotoxic effect in a normal human uterine smooth muscle (UtSM) cell line. However, the mechanisms of this inhibition are unclear. Of note, cyclooxygenase 2 (COX2) and pituitary tumor-transforming gene 1 (PTTG1) are overexpressed in human uterine leiomyomata and are involved in the pathogenesis of uterine fibroids (UFs). We found that COX2 and PTTG1 were overexpressed in UtLM and that BBR decreased COX2 and PTTG1 expression in UtLM cells. Our data support that UtLM and UtSM are immortalized cell lines without phenotypic alterations from parental cell types and suggest that COX2 and PTTG1 are molecular targets for BBR. However, studies in these cell lines may not reveal all activities of BBR in vivo, and we therefore proceeded to test in this report the antitumor effects of BBR in an UF nude mouse xenograft model. When UF nude mice were killed at 7 weeks, tumor weight in controls was 45 ± 7 mg versus 20 ± 3 mg ( P < .05) in the low-dose (5 mg/kg) and 7 ± 3 mg ( P < .01) in the high-dose (10 mg/kg) BBR groups, respectively. Expression of proliferation markers, cell cycle-related genes, and UF-related genes was downregulated in tumors. No unusual behavioral changes and no signs of kidney or liver damage were observed in the animals with BBR treatment. In conclusion, our data suggests that (a) COX2 and PTTG1 are molecular targets for BBR and (b) BBR is potentially an effective and safe anti-UF agent.