Targeting fibrotic signaling pathways by EGCG as a therapeutic strategy for uterine fibroids.

Fibrosis is characterized by excessive accumulation of extracellular matrix, which is a key feature of uterine fibroids. Our prior research supports the tenet that inhibition of fibrotic processes may restrict fibroid growth. Epigallocatechin gallate (EGCG), a green tea compound with powerful antioxidant properties, is an investigational drug for uterine fibroids. An early phase clinical trial showed that EGCG was effective in reducing fibroid size and its associated symptoms; however, its mechanism of action(s) has not been completely elucidated. Here, we probed effects of EGCG on key signaling pathways involved in fibroid cell fibrosis. Viability of myometrial and fibroid cells was not greatly affected by EGCG treatment (1-200 µM). Cyclin D1, a protein involved in cell cycle progression, was increased in fibroid cells and was significantly reduced by EGCG. EGCG treatment significantly reduced mRNA or protein levels of key fibrotic proteins, including fibronectin (FN1), collagen (COL1A1), plasminogen activator inhibitor-1 (PAI-1), connective tissue growth factor (CTGF), and actin alpha 2, smooth muscle (ACTA2) in fibroid cells, suggesting antifibrotic effects. EGCG treatment altered the activation of YAP, ß-catenin, JNK and AKT, but not Smad 2/3 signaling pathways involved in mediating fibrotic process. Finally, we conducted a comparative study to evaluate the ability of EGCG to regulate fibrosis with synthetic inhibitors. We observed that EGCG displayed greater efficacy than ICG-001 (ß-catenin), SP600125 (JNK) and MK-2206 (AKT) inhibitors, and its effects were equivalent to verteporfin (YAP) or SB525334 (Smad) for regulating expression of key fibrotic mediators. These data indicate that EGCG exhibits anti-fibrotic effects in fibroid cells. These results provide insight into mechanisms behind the observed clinical efficacy of EGCG against uterine fibroids.

Immunohistochemical Expression of Vitamin D Receptor in Uterine Fibroids.

One of the many factors involved in the development of uterine fibroids is vitamin D deficiency. One aspect of this deficiency is decreased serum concentration of calcidiol-25(OH)D, a metabolite of D3 vitamin. The active form of vitamin D3, which arises after numerous enzymatic reactions, is calcitriol-1,25(OH)2D3; this compound is transported to various body tissues. Vitamin D possesses extra-genomic effects due to its influence on various signaling pathways, i.e., through activating tyrosine kinases and by genomic effects via binding to a specific nuclear receptor, vitamin D receptor (VDR). The vitamin D/VDR complex regulates the expression of genes and is involved in the pathogenesis of fibroids. Numerous studies have shown that vitamin D supplementation reduces fibroid size. It has also been shown that the expression of VDR in myoma tissue is significantly lower than in the uterine muscle tissue at the tumor periphery. However, the expression of VDR in non-myoma uterine muscle has not previously been investigated. Our VDR expression studies were performed immunohistochemically with tissue microarrays (TMA) in three tissue groups: 98 uterine myoma tissues, 98 uterine tissues (tumor margin), and 12 tissues of normal uterine muscle (i.e., without fibroids). A statistical analysis showed significantly lower VDR expression in uterine muscle at the periphery of the fibroid than in healthy uterine muscle. Lower expression of VDR at the periphery of the myoma compared to that in normal uterine muscle may indicate potential for new myomas. This observation and the described reduction in the size of fibroids after vitamin D supplementation supports the hypothesis of causal development of uterine fibroids and may be useful for the prevention of re-development in the event of their excision from the uterus.

Network pharmacology evaluation of the active ingredients and potential targets of XiaoLuoWan for application to uterine fibroids.

XiaoLuoWan (XLW) is a classical formula in traditional Chinese medicine (TCM) that has satisfactory therapeutic effects for uterine fibroids (UFs). However, its underlying mechanisms remain unclear. To elucidate the pharmacological actions of XLW in treating UFs, an ingredient-target-disease framework was proposed based on network pharmacology strategies. The active ingredients in XLW and their putative targets were obtained from the TCM systems pharmacology database and analysis platform (TCMSP) and Bioinformatics Analysis Tool for Molecular mechANism of Traditional Chinese Medicine (BATMAN-TCM) platforms. The known therapeutic targets of UFs were acquired from the DigSee and DrugBank databases. Then, the links between putative XLW targets and therapeutic UF targets were identified to establish interaction networks by Cytoscape. Finally, Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses of overlapping gene targets were performed in the STRING database and visualized in R software. In total, 9 active compounds were obtained from 74 ingredients, with 71 curative targets predicted in XLW. Moreover, 321 known therapeutic targets were closely related to UFs, with 29 targets overlapping with XLW and considered interacting genes. Pathway enrichment revealed that the calcium signaling pathway was significantly enriched and the mitogen-activated protein kinase (MAPK) signaling pathway, cAMP signaling pathway, cancer and vascular smooth muscle contraction pathways, cGMP-PKG signaling pathway, and AGE-RAGE signaling pathway were closely associated with XLW intervention for UFs. In conclusion, the network pharmacology detection identified 9 available chemicals as the active ingredients in XLW that may relieve UFs by regulating 29 target genes involved in the calcium signaling pathway, MAPK pathway and cAMP pathway. Network pharmacology analyses may provide more convincing evidence for the investigation of classical TCM prescriptions, such as XLW.

Transcriptional profiling of uterine leiomyoma rats treated by a traditional herb pair, Curcumae rhizoma and Sparganii rhizoma.

The aim of this study was to elucidate the concise effects of a traditional herb pair, Curcumae rhizoma-Sparganii rhizoma (CRSR), on uterine leiomyoma (UL) by analyzing transcriptional profiling. The UL rat model was made by intramuscular injection of progesterone and gavage administration of diethylstilbestrol. From 11 weeks of the establishment of the model, rats of the UL+CRSR group were gavaged daily with CRSR (6.67 g/kg). The serum concentrations of progesterone (P) and estradiol (E2) were determined by radioimmunoassay, the uterine index was measured by caliper measurement, and the pathological status was observed by hematoxylin and eosin stain. Gene expression profiling was checked by NimbleGen Rat Gene Expression Microarrays. The results indicated that the uterine mass of UL+CRSR rats was significantly shrunk and serum P and E2 levels significantly reduced compared to UL animals and nearly to the level of normal rats. Results of microarrays displayed the extensive inhibition of CRSR upon the expression of proliferation and deposition of extracellular matrix (ECM)-related genes, and significantly regulated a wide range of metabolism disorders. Furthermore, CRSR extensively regulated key pathways of the UL process, such as MAPK, PPAR, Notch, and TGF-ß/Smad. Regulation of the crucial pathways for the UL process and ECM metabolism may be the underlying mechanisms of CRSR treatment. Further studies will provide clear clues for effectively treating UL with CRSR.

Transcriptional profiling of uterine leiomyoma rats treated by a traditional herb pair, Curcumae rhizoma and Sparganii rhizoma

The aim of this study was to elucidate the concise effects of a traditional herb pair, Curcumae rhizoma-Sparganii rhizoma (CRSR), on uterine leiomyoma (UL) by analyzing transcriptional profiling. The UL rat model was made by intramuscular injection of progesterone and gavage administration of diethylstilbestrol. From 11 weeks of the establishment of the model, rats of the UL+CRSR group were gavaged daily with CRSR (6.67 g/kg). The serum concentrations of progesterone (P) and estradiol (E2) were determined by radioimmunoassay, the uterine index was measured by caliper measurement, and the pathological status was observed by hematoxylin and eosin stain. Gene expression profiling was checked by NimbleGen Rat Gene Expression Microarrays. The results indicated that the uterine mass of UL+CRSR rats was significantly shrunk and serum P and E2 levels significantly reduced compared to UL animals and nearly to the level of normal rats. Results of microarrays displayed the extensive inhibition of CRSR upon the expression of proliferation and deposition of extracellular matrix (ECM)-related genes, and significantly regulated a wide range of metabolism disorders. Furthermore, CRSR extensively regulated key pathways of the UL process, such as MAPK, PPAR, Notch, and TGF-β/Smad. Regulation of the crucial pathways for the UL process and ECM metabolism may be the underlying mechanisms of CRSR treatment. Further studies will provide clear clues for effectively treating UL with CRSR.

Omega-3 fatty acids modulate the lipid profile, membrane architecture, and gene expression of leiomyoma cells.

Uterine leiomyomas (fibroids or myomas) are the most common benign tumors of premenopausal women and new medical treatments are needed. This study aimed to determine the effects of omega-3 fatty acids on the lipid profile, membrane architecture and gene expression patterns of extracellular matrix components (collagen1A1, fibronectin, versican, or activin A), mechanical signaling (integrin ß1, FAK, and AKAP13), sterol regulatory molecules (ABCG1, ABCA1, CAV1, and SREBF2), and mitochondrial enzyme (CYP11A1) in myometrial and leiomyoma cells. Myometrial tissues had a higher amount of arachidonic acid than leiomyoma tissues while leiomyoma tissues had a higher level of linoleic acid than myometrial tissues. Treatment of primary myometrial and leiomyoma cells with eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) reduced the monounsaturated fatty acid (MUFA) content and increased the polyunsaturated fatty acid (PUFA) content in both cell types. Myometrial and leiomyoma cell membranes were in the liquid-crystalline phase, but EPA- and DHA-treated cells had decreased membrane fluidity. While we found no changes in the mRNA expression of ECM components, EPA and DHA treatment reduced levels of ABCG1, ABCA1, and AKAP13 in both cell types. EPA and DHA also reduced FAK and CYP11A1 expression in myometrial cells. The ability of omega-3 fatty acids to remodel membrane architecture and downregulate the expression of genes involved in mechanical signaling and lipid accumulation in leiomyoma cells offers to further investigate this compound as preventive and/or therapeutic option.

An anthocyanin rich strawberry extract induces apoptosis and ROS while decreases glycolysis and fibrosis in human uterine leiomyoma cells.

Uterine leiomyomas are highly prevalent benign tumors in reproductive aged women. Unfortunately, medical treatments are still limited and no preventive therapies have been developed. In the present study, we investigated the therapeutic effects of strawberry extract on uterine leiomyoma cells. Leiomyoma and myometrial cells were treated with strawberry (cultivar Alba) extract (250 µg/ml) for 48 h to measure apoptosis, reactive oxygen species (ROS), oxidative phosphorylation (OCR, oxygen consumption rate) and glycolysis (ECAR, extracellular acidification rate) as well as fibrosis associated gene and/or protein expression. In leiomyoma cells, strawberry increased the percentage of apoptotic and dead cells. Strawberry significantly increased ROS concentration in leiomyoma cells, while decreased it in myometrial cells. After strawberry treatment, leiomyoma cells showed a significant decreased rate of ECAR, while OCR was unchanged in both myometrial and leiomyoma cells. Strawberry significantly decreased collagen1A1, fibronectin and versican mRNA expression in leiomyoma cells. The reduced protein expression of fibronectin was observed by strawberry extract in leiomyoma cells as well. Furthermore, strawberry was able to reduce activin A induced fibronectin, collagen1A1, and versican as well as activin A and PAI-1 mRNA expression in leiomyoma cells. This study suggests that strawberry can be developed as therapeutic and/or preventive agent for uterine leiomyomas.

Lichong decoction reduces Matrix Metalloproteinases-2 expression but increases Tissue Inhibitors of Matrix Metalloproteinases-2 expression in a rat model of uterine leiomyoma.

OBJECTIVE: To study the effect of Lichong decoction (LD) on expression of matrix metalloproteinase- 2 (MMP-2) and metalloproteinase-2 (TIMP-2) in a rat model of uterine leiomyoma (UL). METHODS: UL was induced in rats using exogenous estrogen and progesterone. LD was administered (p.o.) for 4 weeks, and mifepristone (RU-486) used as a control. To observe the effect of LD on the uterine coefficient and uterine transverse diameter, a radioimmunoassay method was used to detect serum levels of sex hormones. Light microscopic analyses of pathologic changes in the tissues of UL rats were evaluated. Expression of the proteins of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in uterine tissues was assessed by immunohistochemical staining and western blotting. RESULTS: A UL model in rats was established successfully. LD reduced uterine weight, uterine coefficient, and uterine transverse diameter compared with untreated controls. LD reduced levels of estradiol, progesterone, follicle-stimulating hormone, and luteinizing hormone in our UL models. LD improved the pathologic condition of uterine muscle. Expression of MMP-2 protein decreased to varying extents in LD-treated groups, but TIMP-2 levels were enhanced. LD appears to reduce MMP-2 expression and increase TIMP-2 expression in UL tissue. CONCLUSION: These data suggest that the mechanism of action of LD on ULs may involve reduction of MMP-2 expression and increase in TIMP-2 expression in rats.

[Study of effective components and molecular mechanism for Guizhi Fuling formula treatment of dysmenorrhea, pelvic inflammatory disease and uterine fibroids].

In this study, the active components and potential molecular .mechanism of Guizhi Fuling formula in treatment on dysmenorrhea, pelvic inflammation, and hysteromyoma were investigated using network pharmacological methods. Sterols and pentacyclic triterpenes, with high moleculal network degree, revealed promising effects on anti-inflammatory, analgesic, anti-tumor, and immune-regulation, according to D-T network analysis. On the other hand, the targets with high degree were involved in inflammatory, coagulation, angiopoiesis, smooth muscle contraction, and cell reproduction, which showed the novel function in anti-dysmenorrhea, pelvic inflammation, and hysteromyoma. Furthermore, the formula was indicated to play a key role in smooth muscle proliferation, inhibition of new vessels, circulation improvement, reduction of hormone secretion, alleviation of smooth muscle, block of arachidonic acid metabolism, and inflammation in uterus. Thus, the main mechanism of Guizhi Fuling formula was summarized. In conclusion, Guizhi Fuling formula was proven to alleviated dysmenorrhea, pelvic inflammation, and hysteromyoma by acting on multiple targets through several bioactive compounds, regulating 21 biological pathways.

2-Methoxyestradiol causes functional repression of transforming growth factor ß3 signaling by ameliorating Smad and non-Smad signaling pathways in immortalized uterine fibroid cells.

OBJECTIVE: To investigate the effects and the mechanism of action of 2-methoxyestradiol (2ME(2)) on transforming growth factor (TGF) ß3-induced profibrotic response in immortalized human uterine fibroid smooth muscle (huLM) cells. DESIGN: Laboratory study. SETTING: University research laboratory. PATIENTS(S): Not applicable. INTERVENTIONS(S): Not applicable. MAIN OUTCOME MEASURE(S): huLM cells were treated with TGF-ß3 (5 ηg/mL) in the presence or absence of specific Smad3 inhibitor SIS3 (1 µmol/L), inhibitor of the PI3K/Akt (LY294002, 10 µmol/L), or 2ME(2) (0.5 µmol/L), and the expression of collagen (Col) type I(αI), Col III(αI), plasminogen activator inhibitor (PAI) 1, connective tissue growth factor (CTGF), and α-smooth muscle actin (α-SMA) were determined by real-time reverse-transcription polymerase chain reaction and immunoblotting. The effect of 2ME(2) on Smad-microtubule binding was evaluated by coimmunoprecipitation. RESULT(S): Our data revealed that TGF-ß3-induced fibrogenic response in huLM is mediated by both Smad-dependent and Smad-independent PI3K/Akt/mTOR signaling pathways. 2ME(2) abrogates TGF-ß3-induced expression of Col I(αI), Col III(αI), PAI-1, CTGF, and α-SMA. Molecularly, 2ME(2) ameliorates TGF-ß3-induced Smad2/3 phosphorylation and nuclear translocation. In addition, 2ME(2) inhibits TGF-ß3-induced activation of the PI3K/Akt/mTOR pathway. CONCLUSION(S): TGF-ß3-induced profibrotic response in fibroid cells is mediated by Smad-dependent and Smad-independent PI3K/Akt/mTOR pathways. 2ME(2) inhibits TGF-ß3 profibrotic effects in huLM cells by ameliorating both Smad-dependent and Smad-independent signaling pathways.

Leiomyoma: genetics, assisted reproduction, pregnancy and therapeutic advances.

PURPOSE: Uterine leiomyomas are common, benign, reproductive tract tumors affecting a majority of reproductive aged women. They are associated with gynecologic morbidity and detrimentally affect reproductive potential. The etiology of leiomyomas is poorly understood and their diagnosis prior to treatment with Assisted Reproductive Technologies (ART) represents a management dilemma. The purpose of this paper is to review known genetic and molecular contributions to the etiologies of leiomyomas, describe their impact on ART outcomes and reproductive potential, and review alternative therapies and future directions in management. METHODS: A critical review of the literature pertaining to genetic component of uterine leiomyomas, their impact on ART and pregnancy and leiomyoma therapeutics was performed. RESULTS: Uterine leiomyomas are characterized by complex molecular mechanisms. Their location and size determines their potential detriment to ART and reproductive function and novel therapeutic modalities are being developed. CONCLUSION: The high prevalence of uterine leiomyomas and their potential detrimental influence on ART and reproductive function warrants continued well-designed studies to ascertain their etiology, optimal treatment and novel less morbid therapies.

Effect of lichong decoction on expression of IGF-I and proliferating cell nuclear antigen mRNA in rat model of uterine leiomyoma.

OBJECTIVE: To study the effect of Lichong Decoction (Lichong Decoction for strengthening anti-pathogenic Qi and eliminating blood stasis) on the expression of insulin-like growth factor-I (IGF-I) and proliferating cell nuclear antigen (PCNA) mRNA in a rat model of uterine leiomyoma. METHODS: Fifty female Wistar rats were randomized into a normal control group, model group, Lichong Decoction group, Guizhifuling Capsule (Capsule containing Cassia Twig and Poria) group, and Mifepristone group. The uterine leiomyoma model was established by peritoneal injections of exogenous estrogen and progesterone hormone. The ultrastructural changes in cells of rat uterine tissues were observed with transmission electron microscopy, and the expression of IGF-I and PCNA mRNA was detected by real-time fluorescent quantitative PCR. RESULTS: Following treatment, cells in the Lichong Decoction group appeared to be arranged normally, the cellular morphology were almost in a normal state, hyperplasia and hypertrophy of the chondriosome was reduced, collagen fibers were arranged in a regular manner, without obvious hyperplasia, and the expression of IGF-I and PCNA mRNA was significantly decreased compared with the model group (P < 0.01). CONCLUSIONS: The effect of Lichong Decoction on uterine leiomyoma is related to its function in reducing the expression of IGF-I and PCNA mRNA.

1,25-Dihydroxyvitamin D3 reduces TGF-beta3-induced fibrosis-related gene expression in human uterine leiomyoma cells.

BACKGROUND: Uterine leiomyomas (fibroids) are the most common benign estrogen-dependent tumors of premenopausal women. TGF-ß3 up-regulates the synthesis of many of extracellular matrix proteins that are associated with tissue fibrosis. OBJECTIVE: To examine the effect of 1,25-dihydroxyvitamin D(3) (vitamin D(3)) on TGF-ß3-induced fibrosis-related protein expression in immortalized human uterine leiomyoma (HuLM) cells. METHODS: HuLM cells were treated with TGF-ß3 with or without vitamin D(3). Western blot analyses were employed to test the effect of vitamin D(3) on TGF-ß3-induced protein expression of collagen type 1, fibronectin, and plasminogen activator inhibitor-1 proteins. Western blots as well as immunofluorescence analyses were used to verify the effect of vitamin D(3) on TGF-ß3-induced Smad activation involved in extracellular matrix protein synthesis and deposition, which ultimately lead to tissue fibrosis. RESULTS: We observed that TGF-ß3 induced fibronectin and collagen type 1 protein expression in HuLM cells, and that effect was suppressed by vitamin D(3). TGF-ß3 also induced protein expression of plasminogen activator inhibitor-1, an important TGF-ß target, in HuLM cells, which was also inhibited by vitamin D(3). Additionally, TGF-ß3 induced phosphorylation of Smad2 as well as nuclear translocation of Smad2 and Smad3 in HuLM cells, whereas vitamin D significantly reduced all these TGF-ß3-mediated effects. Therefore, our results suggest that vitamin D(3) has consistently reduced TGF-ß3 effects that are involved in the process of fibrosis in human leiomyoma cells. CONCLUSION: Vitamin D(3) is an antifibrotic factor that might be potentially useful as a novel therapeutic for nonsurgical treatment of benign uterine fibroids.

Curcumin, a nutritional supplement with antineoplastic activity, enhances leiomyoma cell apoptosis and decreases fibronectin expression.

OBJECTIVE: To determine if curcumin has an antiproliferative effect on leiomyoma cells via apoptosis induction and whether curcumin impacts extracellular matrix (ECM) production by assessing the fibronectin expression in leiomyoma cells treated with curcumin. DESIGN: Tissue culture study of immortalized human leiomyoma and patient-matched myometrial cells treated with curcumin. SETTING: University hospital. PATIENT(S): Immortalized leiomyoma and myometrial cells from patients with symptomatic leiomyomata. INTERVENTION(S): Tissue culture, followed by proliferation studies, RNA, and protein analysis. MAIN OUTCOME MEASURE(S): Cell proliferation, alteration in apoptotic signaling pathways. RESULT(S): Curcumin demonstrated an antiproliferative effect on leiomyoma cell lines (IC50 = 20 muM). Importantly, no statistically significant inhibition of growth was observed when patient-matched myometrial cells were exposed to equivalent concentrations of curcumin. Curcumin stimulated caspase-3 and caspase-9 expression while inhibiting extracellular signal-regulated kinase 1 (ERK 1), ERK 2, and nuclear factor kappa B (NF-kappaB), suggesting regulation of leiomyocyte apoptosis. Finally, curcumin inhibited expression of fibronectin in leiomyoma cells. CONCLUSION(S): Our findings demonstrate that curcumin inhibited uterine leiomyoma cell proliferation via regulation of the apoptotic pathway, and inhibited production of the ECM component fibronectin. Curcumin provides a novel direction for leiomyoma therapies.

Antiproliferative effect of Scutellaria barbata D. Don. on cultured human uterine leiomyoma cells by down-regulation of the expression of Bcl-2 protein.

Scutellaria barbata D. Don (Lamiaceae; SB) inhibited the growth of leiomyomal cells (LM). A time-dependent antiproliferative effect was noted when 10(-5) m buserelin, gonadotrophin-releasing hormone (GnRH) agonist or 20-40 microg/mL SB was added. The inhibition of cell growth decreased with the addition of the PKC activator (12-O-tetradecanoylphorbor-13-acetate; TPA) much as it did with the addition of SB, and the decreases in the viable cells caused by the addition of SB were reversed completely by pretreatment with a protein kinase C (PKC) inhibitor (calphostin C). The findings suggest that SB inhibits cell proliferation in cultured human uterine leiomyoma cells accompanied by PKC activation. Next, the study investigated the effect of SB on fetal development for toxicity. Pregnant Sprague-Dawley rats, from gestation day 6-15, were administered 20 g/L or 50 g/L SB in the drinking water and then killed on day 20. No maternal toxicity was observed, however, embryonic loss in the treatment groups was double that of the controls (p < 0.05). No gross morphologic malformations were seen in the treated fetuses. Fetuses exposed to SB were found to be significantly heavier than the controls, an effect that was greater in female fetuses and was not correlated with increased placental size. The results suggest that the SB had no toxicity and that in utero exposure to SB resulted in increased early embryo loss with increased growth in surviving fetuses. On the other hand, Western blot analyses revealed that Bcl-2 protein of a 26 kDa was abundant in leiomyomal cells, but not in normal myometrial cells. The addition of progesterone (100 ng/mL) resulted in a striking increase in Bcl-2 protein expression in the cultured leiomyoma cells. However, the addition of SB (20 microg/mL) resulted in a significant reduction in Bcl-2 protein expression in the cells. The results indicated that human uterine leiomyomal cells express Bcl-2 protein and progesterone enhances its expression, however, SB reduces the expression of Bcl-2 protein in human uterine leiomyoma cells.

Retinoic acid treatment of human leiomyoma cells transformed the cell phenotype to one strongly resembling myometrial cells.

BACKGROUND: Uterine leiomyomas are clinically significant tumours that may develop due to an altered differentiation pathway. We have previously identified a dysregulated retinoic acid (RA) pathway that reduced retinoic exposure in human leiomyoma surgical specimens, and have shown that the leiomyoma phenotype was characterized by excessive and disorganized extracellular matrix (ECM). OBJECTIVE: The goal of this study was to determine the impact of RA exposure on the disrupted ECM phenotype of leiomyomas. DESIGN AND METHODS: Study of immortalized and molecularly confirmed cells generated from surgical specimens of spontaneous uterine leiomyoma and matched myometrium. RESULTS: Immortalized leiomyoma and myometrial cells retained the molecular characteristics of their progenitor tissue. Proliferation of leiomyoma cells was inhibited by all-trans retinoic acid (ATRA). Furthermore, there was a dose-dependent decrease in soluble extracellular collagen protein in ATRA-treated leiomyoma cells. Exposure of leiomyoma cells to ATRA resulted in a dose-dependent inhibition of templates for specific ECM protein production including collagen 1, collagen 4, fibronectin and versican. Notably, expression levels in treated leiomyoma cells approached those found in myometrial cells. These mRNA alterations translated into altered protein. Down-regulation was also observed among the RA pathway genes such as CYP26A1 with exposure to ATRA. Finally, ATRA down-regulated TGF-beta3 mRNA expression and the TGF-beta regulated genes in leiomyoma cells. CONCLUSION: Exposure of leiomyomas to ATRA down-regulated cell proliferation, ECM formation, RA metabolism and TGF-beta regulation, suggesting that RA exposure can alter the leiomyoma phenotype to one that more closely approximates normal myometrium.

Aromatase expression in uterine leiomyomata is regulated primarily by proximal promoters I.3/II.

CONTEXT: Uterine leiomyomata are common tumors that cause irregular uterine bleeding and pregnancy loss and depend on estrogen for growth. Aromatase catalyzes the conversion of androgens to estrogens. Aromatase expression is regulated via alternatively used promoters in the placenta (I.1 and I.2a), fat (I.4, I.3, and II), bone (I.6), and gonads (II). A prostaglandin E(2)/cAMP-dependent pathway regulates coordinately the proximal promoters I.3/II, whereas glucocorticoids and cytokines regulate the distal promoter I.4. Use of each promoter gives rise to a population of aromatase mRNA species with unique 5'-untranslated regions (5'-UTRs). Uterine leiomyoma tissue, but not normal myometrium, overexpresses aromatase leading to estrogen-stimulated cell proliferation. Aromatase inhibitor treatment shrank uterine leiomyomata in a few women. OBJECTIVE AND DESIGN: Promoter I.4 was reported to regulate aromatase expression in uterine leiomyomata from a group of Japanese women. Here, we used two independent techniques to identify the promoters that regulate aromatase expression in uterine leiomyomata (n = 30) from 23 African-American, Hispanic, and white women. RESULTS: Rapid amplification of 5'-cDNA ends of aromatase mRNA species revealed the following distribution of promoter usage in leiomyomata: promoters I.3/II, 61.5%; I.2a, 15.4%; I.6, 15.4%; and I.4, 7.7%. Real-time PCR, which quantifies mRNA species with promoter-specific 5'-UTRs, revealed the following distribution for each 5'-UTR as a fraction of total aromatase mRNA: I.3/II, 69.6%; I.4, 7.3%; and other promoters, 23.1%. CONCLUSIONS: The primary in vivo aromatase promoter in leiomyoma tissues in non-Asian U.S. women is the prostaglandin E(2)/cAMP-responsive I.3/II region. Alternative signals may stimulate aromatase expression that is a common biological phenotype in uterine leiomyomata.

Scutellaria barbata D. Don induces c-fos gene expression in human uterine leiomyomal cells by activating beta2-adrenergic receptors.

Scutellaria barbata D. Don (Lamiaceae; SB) inhibited the growth of uterine leiomyomal (LM) cells with unknown actions. The expression patterns of beta-adrenergic receptors (beta-ARs) in human uterine LM cells and functional coupling to gene expression have also been investigated. Northern blot analysis showed that beta-AR subtypes are expressed at different levels in the uterine LM cells and myometrial smooth muscle cells (SMCs). beta1-AR expression was to be found approximately at the same level in the two cell types. beta2-ARs were expressed at higher levels in uterine LM cells than that in myometrial SMCs. beta3-AR expression was not found in both the cells. c-fos gene expression was induced by SB in uterine LM cells via increases in adenosine-3',5', cyclic monophosphate (cAMP), which in turn activated the cAMP/protein kinase A (PKA) pathway. The PKA inhibitor, H89, inhibited c-fos gene expression induced by SB. It seems that the mechanism of proto-oncogenes c-fos different leiomyoma from other myometrial cancer. Further studies are necessary to elucidate whether c-fos induction by SB in uterine LM cells influences a regression of leiomyoma or induces other differentiation.

Up-regulation by IGF-I of proliferating cell nuclear antigen and Bcl-2 protein expression in human uterine leiomyoma cells.

IGF-I has been reported to play a role in regulating proliferation of human leiomyoma cells. There is, however, little evidence to suggest that IGF-I inhibits apoptosis in the leiomyoma cells. The present study was conducted to elucidate whether IGF-I affects apoptosis and Bcl-2 protein expression, an apoptosis-inhibiting gene product, in cultured leiomyoma cells. In addition, we examined the effect of IGF-I on proliferating cell nuclear antigen (PCNA) expression in cultured leiomyoma cells. Isolated human leiomyoma cells were subcultured in phenol red-free DMEM supplemented with 10% FBS for 120 h and then stepped down to serum-free conditions for an additional 72 h in the absence or presence of graded concentrations of IGF-I (1.0, 10, and 100 ng/ml). The effects of IGF-I on Bcl-2 protein and PCNA expression in cultured leiomyoma cells were assessed by Western immunoblot analysis and immunocytochemical staining, whereas the effects of IGF-I on the cell viability and apoptosis of the cultured cells were determined by 3-(4,5-dimethylatriazol-2-yl)-2,5diphenyltetrasodium bromide (MTT) assay and terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick end labeling assay, respectively. Immunocytochemical staining demonstrated that IGF-I treatment resulted in the increase in PCNA labeling index in cultured leiomyoma cells in a dose-dependent manner. Immunoblot analysis of proteins extracted from the cultured leiomyoma cells revealed that the addition of IGF-I (10 and 100 ng/ml) significantly increased the expression of 35-kDa immunoreactive PCNA and 26-kDa Bcl-2 protein, compared with those in control cultures. Cell survival and proliferation of cultured leiomyoma cells, assessed by MTT assay, was significantly augmented by IGF-I treatment, compared with those of control cultures. Terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick end labeling assay showed that the apoptosis-positive rate of leiomyoma cells treated with IGF-I was significantly decreased, compared with that in control cultures. The present results suggest that IGF-I plays crucial roles in leiomyoma cell growth, not only in promoting the proliferative potential by up-regulation of PCNA expression but also in down-regulating apoptosis by up-regulation of Bcl-2 protein expression in leiomyoma cells.

Expression of leptin receptor in human endometrium and fluctuation during the menstrual cycle.

Leptin is secreted by adipocytes and regulates appetite through interaction with hypothalamic leptin receptors (OB-R). Accumulated evidence shows that leptin is involved in the stimulation of reproductive functions and that local expression of leptin and OB-R in the ovary, oocyte, embryo, and placenta plays a role in early development. To investigate the role of leptin in implantation, we examined the expression of OB-R and leptin in the human endometrium. Northern and Western blot analyses and RT-PCR showed that the long form of OB-R (OB-R(L)) messenger ribonucleic acid (mRNA) and protein were expressed. In contrast, leptin mRNA or protein was not detected. All of the splice variants of OB-R (OB-R(T)) and OB-R(L) transcripts were expressed in 90% and 84% of the cases, respectively. OB-R mRNA expression peaked in the early secretory phase. Decidual tissue of early gestation also expressed OB-R(T) and OB-R(L). Their incidence and abundance were comparable among endometria with benign uterine diseases and disease-free endometria and were not related to a body mass index within the normal range. The present results indicate that OB-R, but not leptin, is expressed in the human endometrium.