Leiomyoma and myometrial gene expression profiles and their responses to gonadotropin-releasing hormone analog therapy

Relugolix and elagolix directly inhibit leiomyoma extracellular matrix production in 2-dimesnional and 3-dimensional cell cultures

OBJECTIVE

To determine the effect relugolix and elagolix have on the production of extracellular matrix (ECM) proteins in human leiomyoma cells.

DESIGN

Laboratory study.

SETTING

University hospital.

PATIENT(S) OR ANIMALS

None. January 5, 2022 Cell culture, protein analysis, immunohistochemistry.

MAIN OUTCOME MEASURE(S)

Production of GnRHR, COL1A1, FN1, VCAN, p-ERK, & ERK in treated/untreated leiomyoma cells.

RESULTS

100 nM relugolix resulted in decreased production of COL1A1 at 24 (1.78 0.06-fold; P < .05) and 48 hours (1.92 0.14-fold; P < .05). Elagolix treatment resulted in a decrease in COL1A1 production at 24 but not 48 hours. In 2D and 3D, 100 nM relugolix resulted in decreased production of FN1 at 24 (1.7 ± 0.07-fold; P < .05) and 48 hours (1.8 ± 0.07-fold; P < .05); 100 nM elagolix resulted in decreased production of FN1 at 24 (1.7 ± 0.14-fold; P < .05) and 48 hours (2.0 ± 0.09-fold; P < .05). For cells treated with relugolix 100 nM resulted in decreased VCAN production by 48 hours (0.66 ± 0.07-fold; P < .05). Contrary to our 3D data, 2D elagolix-treated cells demonstrated a decrease in VCAN production that was identified only at 24 hours. For GnRHR, no significant difference between the drugs was seen at 24 hours; at 48 hours production was only significantly decreased for relugolix (P < .05). Comparing both drugs, there was a significant difference in the concentration of p-ERK to ERK at 24 hours (P < .05); there was no difference by 48 hours.

CONCLUSIONS

Our findings demonstrated that treatment with either drug can 1) decrease ECM protein production and 2) inhibit the MAPK pathway.

GRK5 Deficiency Causes Mild Cognitive Impairment due to Alzheimer's Disease

Prevention of Alzheimer's disease (AD) is a high priority mission while searching for a disease modifying therapy for AD, a devastating major public health crisis. Clinical observations have identified a prodromal stage of AD for which the patients have mild cognitive impairment (MCI) though do not yet meet AD diagnostic criteria. As an identifiable transitional stage before the onset of AD, MCI should become the high priority target for AD prevention, assuming successful prevention of MCI and/or its conversion to AD also prevents the subsequent AD. By pulling this string, one demonstrated cause of amnestic MCI appears to be the deficiency of G protein-coupled receptor-5 (GRK5). The most compelling evidence is that GRK5 knockout (GRK5KO) mice naturally develop into aMCI during aging. Moreover, GRK5 deficiency was reported to occur during prodromal stage of AD in CRND8 transgenic mice. When a GRK5KO mouse was crossbred with Tg2576 Swedish amyloid precursor protein transgenic mouse, the resulted double transgenic GAP mice displayed exaggerated behavioral and pathological changes across the spectrum of AD pathogenesis. Therefore, the GRK5 deficiency possesses unique features and advantage to serve as a prophylactic therapeutic target for MCI due to AD.

Understanding the Impact of Uterine Fibroids on Human Endometrium Function

Uterine fibroids (leiomyomas) are the most common benign gynecological tumors in women of reproductive age worldwide. They cause heavy menstrual bleeding, usually leading to severe anemia, pelvic pain/pressure, infertility, and other debilitating morbidities. Fibroids are believed to be monoclonal tumors arising from the myometrium, and recent studies have demonstrated that fibroids actively influence the endometrium globally. Studies suggest a direct relationship between the number of fibroids removed and fertility problems. In this review, our objective was to provide a complete overview of the origin of uterine fibroids and the molecular pathways and processes implicated in their development and growth, which can directly affect the function of a healthy endometrium. One of the most common characteristics of fibroids is the excessive production of extracellular matrix (ECM) components, which contributes to the stiffness and expansion of fibroids. ECM may serve as a reservoir of profibrotic growth factors such as the transforming growth factor β (TGF-β) and a modulator of their availability and actions. Fibroids also elicit mechanotransduction changes that result in decreased uterine wall contractility and increased myometrium rigidity, which affect normal biological uterine functions such as menstrual bleeding, receptivity, and implantation. Changes in the microRNA (miRNA) expression in fibroids and myometrial cells appear to modulate the TGF-β pathways and the expression of regulators of ECM production. Taken together, these findings demonstrate an interaction among the ECM components, TGF-β family signaling, miRNAs, and the endometrial vascular system. Targeting these components will be fundamental to developing novel pharmacotherapies that not only treat uterine fibroids but also restore normal endometrial function.

Gonadotropin-releasing hormone analogs: Mechanisms of action and clinical applications in female reproduction

Extra-hypothalamic GnRH and extra-pituitary GnRH receptors exist in multiple human reproductive tissues, including the ovary, endometrium and myometrium. Recently, new analogs (agonists and antagonists) and modes of GnRH have been developed for clinical application during controlled ovarian hyperstimulation for assisted reproductive technology (ART). Additionally, the analogs and upstream regulators of GnRH suppress gonadotropin secretion and regulate the functions of the reproductive axis. GnRH signaling is primarily involved in the direct control of female reproduction. The cellular mechanisms and action of the GnRH/GnRH receptor system have been clinically applied for the treatment of reproductive disorders and have widely been introduced in ART. New GnRH analogs, such as long-acting GnRH analogs and oral nonpeptide GnRH antagonists, are being continuously developed for clinical application. The identification of the upstream regulators of GnRH, such as kisspeptin and neurokinin B, provides promising potential to develop these upstream regulator-related analogs to control the hypothalamus-pituitary-ovarian axis.

Evaluation of goserelin effectiveness based on assessment of inflammatory cytokines and symptoms in uterine leiomyoma

Background Uterine leiomyoma is a benign tumour of the uterine smooth muscles associated with an elevated level of inflammatory cytokines. Goserelin, a synthetic gonadotropin-releasing hormone analogue, suppresses the production of sex hormones and release of inflammatory cytokines in uterine leiomyoma cells. Objective The primary objective of this study was to find out the effectiveness of subcutaneous goserelin therapy on lowering serum levels of inflammatory cytokines and improving uterine leiomyoma-related symptoms in female patients diagnosed with uterine leiomyoma. The secondary objective was to assess the tolerability to goserelin therapy used in the management of this tumour. Setting Outpatient gynaecological clinic of the medical consultation department of Baghdad Teaching Hospital, Baghdad province, Iraq. Methods A single centre, prospective, longitudinal, cohort study was carried out on female patients diagnosed with uterine leiomyoma. Goserelin 3.6 mg subcutaneous injection was given in a consecutive monthly dose for the total time duration of three months. Serum levels of inflammatory cytokines, tumour necrosis factor-α and monocyte chemotactic protein-1 were detected before and after goserelin therapy in a consecutive monthly assessment. The study also assessed the improvement in uterine leiomyoma-related symptoms, including pelvic pain alongside the incidence of goserelin-related side effects during therapy schedules. Main Outcome Measures Assessment of serum levels of tumour necrosis factor-α and monocyte chemotactic protein-1 alongside uterine leiomyoma-related symptoms, including pelvic pain and goserelin-related side effects. Results There was a significant decrease in serum levels of tumour necrosis factor-α and monocyte chemotactic protein-1 compared to the baseline level over the 3-month duration of goserelin therapy (0.11 ± 0.02 vs. 0.74 ± 0.19) pg/mL; (0.07 ± 0.00 vs. 0.44 ± 0.18) pg/mL respectively. Patients showed a clinical improvement regarding uterine leiomyoma-related symptoms following each of the consecutive monthly doses of goserelin therapy (n = 11, 55%, P < 0.0001; n = 15, 75%, P < 0.0001; n = 18, 90%, P < 0.0001) respectively. This also includes a significant decrease in the intensity of leiomyoma-related pelvic pain before and after goserelin therapy (7.2 ± 1.43 vs. 3.05 ± 1.14, P < 0.0001). The majority of patients reported vaginal dryness (60%) as the main goserelin-related side effect. Conclusion Goserelin therapy reduces serum levels of inflammatory cytokines, tumour necrosis factor- α and monocyte chemotactic protein-1, improving leiomyoma-related symptoms with good tolerability in patients with uterine leiomyoma.

Treatment with a GnRH receptor agonist, but not the GnRH receptor antagonist degarelix, induces atherosclerotic plaque instability in ApoE(-/-) mice

Androgen-deprivation therapy (ADT) for prostate cancer has been associated with increased risk for development of cardiovascular events and recent pooled analyses of randomized intervention trials suggest that this primarily is the case for patients with pre-existing cardiovascular disease treated with gonadotropin-releasing hormone receptor (GnRH-R) agonists. In the present study we investigated the effects of the GnRH-R agonist leuprolide and the GnRH-R antagonist degarelix on established atherosclerotic plaques in ApoE^−/− mice. A shear stress modifier was used to produce both advanced and more stable plaques in the carotid artery. After 4 weeks of ADT, increased areas of necrosis was observed in stable plaques from leuprolide-treated mice (median and IQR plaque necrotic area in control, degarelix and leuprolide-treated mice were 0.6% (IQR 0–3.1), 0.2% (IQR 0–4.4) and 11.0% (IQR 1.0-19.8), respectively). There was also evidence of increased inflammation as assessed by macrophage immunohistochemistry in the plaques from leuprolide-treated mice, but we found no evidence of such changes in plaques from control mice or mice treated with degarelix. Necrosis destabilizes plaques and increases the risk for rupture and development of acute cardiovascular events. Destabilization of pre-existing atherosclerotic plaques could explain the increased cardiovascular risk in prostate cancer patients treated with GnRH-R agonists.

Aberrant expression and regulation of NR2F2 and CTNNB1 in uterine fibroids

Uterine fibroids are the most common benign tumour afflicting women of reproductive age. Despite the large healthcare burden caused by fibroids, there is only limited understanding of the molecular mechanisms that drive fibroid pathophysiology. Although a large number of genes are differentially expressed in fibroids compared with myometrium, it is likely that most of these differences are a consequence of the fibroid presence and are not causal. The aim of this study was to investigate the expression and regulation of NR2F2 and CTNNB1 based on their potential causal role in uterine fibroid pathophysiology. We used real-time quantitative RT-PCR, western blotting and immunohistochemistry to describe the expression of NR2F2 and CTNNB1 in matched human uterine fibroid and myometrial tissues. Primary myometrial and fibroid smooth muscle cell cultures were treated with progesterone and/or retinoic acid (RA) and sonic hedgehog (SHH) conditioned media to investigate regulatory pathways for these proteins. We showed that NR2F2 and CTNNB1 are aberrantly expressed in fibroid tissue compared with matched myometrium, with strong blood vessel-specific localisation. Although the SHH pathway was shown to be active in myometrial and fibroid primary cultures, it did not regulateNR2F2orCTNNB1mRNA expression. However, progesterone and RA combined regulatedNR2F2mRNA, but notCTNNB1, in myometrial but not fibroid primary cultures. In conclusion, we demonstrate aberrant expression and regulation of NR2F2 and CTNNB1 in uterine fibroids compared with normal myometrium, consistent with the hypothesis that these factors may play a causal role uterine fibroid development.

Expression profiling of nuclear receptors identifies key roles of NR4A subfamily in uterine fibroids

Uterine fibroids (UFs), also known as uterine leiomyomas, are benign, fibrotic smooth muscle tumors. Although the GnRH analog leuprolide acetate that suppresses gonadal steroid hormones is used as a treatment, it has significant side effects, thereby limiting its use. Availability of more effective therapy is limited because of a lack of understanding of molecular underpinnings of the disease. Although ovarian steroid hormones estrogen and progesterone and their receptors are clearly involved, the role of other nuclear receptors (NRs) in UFs is not well defined. We used quantitative real-time PCR to systematically profile the expression of 48 NRs and identified several NRs that were aberrantly expressed in UFs. Among others, expression of NR4A subfamily members including NGFIB (NR4A1), NURR1 (NR4A2), and NOR1 (NR4A3) were dramatically suppressed in leiomyoma compared with the matched myometrium. Restoration of expression of each of these NR4A members in the primary leiomyoma smooth muscle cells decreased cell proliferation. Importantly, NR4As regulate expressions of the profibrotic factors including TGFβ3 and SMAD3, and several collagens that are key components of the extracellular matrix. Finally, we identify NR4A members as targets of leuprolide acetate treatment. Together, our results implicate several NRs including the NR4A subfamily in leiomyoma etiology and identify NR4As as potential therapeutic targets for treating fibrotic diseases.

miR-200c is aberrantly expressed in leiomyomas in an ethnic-dependent manner and targets ZEBs, VEGFA, TIMP2, and FBLN5

MicroRNA-200c (miR-200c) through repression of specific target genes has been associated with cellular transition, tumorigenesis, and tissue fibrosis. We explored the expression and functional aspects of miR-200c in genesis of leiomyomas (LYO), benign uterine tumors with fibrotic characteristic. Using LYO and matched myometrium (MYO; n=76) from untreated and from patients exposed to hormonal therapies (GNRH agonist (GNRHa), Depo-Provera, and oral contraceptives), we found that miR-200c was expressed at significantly lower levels (P<0.05) in LYO as compared with MYO. These levels were lower in LYO from African Americans as compared with Caucasians, patients experiencing abnormal uterine bleeding and those exposed to GNRHa therapy. Gain-of-function of miR-200c in isolated leiomyoma smooth muscle cells (LSMCs), myometrial smooth muscle cells (MSMCs), and leiomyosarcoma cell line (SKLM-S1) repressed ZEB1/ZEB2 mRNAs and proteins, with concurrent increase in E-cadherin (CDH1) and reduction in vimentin expression, phenotypic alteration, and inhibition of MSMC and LSMC proliferations. We further validated TIMP2, FBLN5, and VEGFA as direct targets of miR-200c through interaction with their respective 3' UTRs, and other genes as determined by microarray analysis. At tissue levels, LYO expressed lower levels of TIMP2 and FBLN5 mRNAs but increased protein expressions, which to some extent altered due to hormonal exposure. Given the regulatory functions of ZEBs, VEGFA, FBLN5, and TIMP2 on cellular activities that promote cellular transition, angiogenesis, and matrix remodeling, we concluded that altered expression of miR-200c may have a significant impact on the outcome of LYO growth, maintenance of their mesenchymal and fibrotic characteristics, and possibly their associated symptoms.

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

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.

Metabolic profile of intact tissue from uterine leiomyomas using high-resolution magic-angle-spinning ¹H NMR spectroscopy

High-resolution magic-angle-spinning (HRMAS) one- and two-dimensional (1)H and (13)C NMR spectroscopy was used to study intact healthy (myometrium) and benign (leiomyoma) uterine tissues of 10 patients. Twenty-eight metabolites were detected and assigned in both types of tissue. Principal component analysis (PCA) was applied to a conventional water-suppressed (1)H HRMAS NMR spectrum, and two NMR spectral editing methods, namely Carr-Purcell- Meiboom-Gill (CPMG) spin-echo and diffusion-edited techniques, were used. Only the PCA of CPMG spectra resulted in a good differentiation between the two tissue types. The CPMG spin-echo spectra were also useful in indicating depleted levels of taurine in uterine leiomyomas, which were well correlated with the histopathological determination. In addition, statistical analysis revealed that most leiomyomas contained elevated concentrations of glutamate and glutamine. Our results suggest that HRMAS represents a valuable adjunct to histopathology to improve the diagnostic accuracy of uterine leiomyomas, whilst concomitantly reducing the diagnosis time.

Proinflammatory and profibrotic mediators: principal effectors of leiomyoma development as a fibrotic disorder

Leiomyomas are believed to derive from the transformation of myometrial smooth muscle cells/connective tissue fibroblasts. Although the identity of the molecule(s) that initiate such cellular transformation and orchestrate subsequent growth is still unknown, conventional evidence indicates that ovarian steroids are essential for leiomyoma growth. Ovarian steroid action in their target cell/tissue is mediated in part through local expression of various growth factors, cytokines, and chemokines. These autocrine/paracrine molecules with proinflammatory and profibrotic activities serve as major contributing factors in regulating cellular transformation, cell growth and apoptosis, angiogenesis, cellular hypertrophy, and excess tissue turnover, events central to leiomyoma growth. This review addresses the key regulatory functions of proinflammatory and profibrotic mediators and their molecular mechanisms, downstream signaling that regulates cellular events that result in transformation, and commitments of specific cells into forming a cellular environment with a possible role in development and subsequent growth of leiomyomas.

microRNA 21: response to hormonal therapies and regulatory function in leiomyoma, transformed leiomyoma and leiomyosarcoma cells

Aberrant expression of microRNAs (miRNAs), including miR-21, and alteration of their target genes stability have been associated with cellular transformation and tumorigenesis. We investigated the expression, regulation and function of miR-21 in leiomyomas which develop from myometrial cellular transformation. The results indicated that miR-21 is over-expressed in leiomyomas with specific elevation during the secretory phase of the menstrual cycle and in women who received Depo-Provera and oral contraceptives, but reduced due to GnRHa therapy (P < 0.05). Bioinformatic analysis of microarray gene expression profiles previously obtained from the above cohorts, and myometrial smooth muscle cells (MSMC) and leiomyoma smooth muscle cells (LSMC) treated with GnRHa, transforming growth factor (TGF)-β and TGF-β receptor type II (TGF-βRII) antisense oligomer, indicated that a number of miR-21-predicted target genes were co-expressed and differentially regulated in these cohorts. Gain- and loss-of-function of miR-21 in MSMC, LSMC, transformed LSMC and leiomyosarcoma cell line (SKLM-S1) resulted in differential expression of many genes, including some of the miR-21-predicted/validated target genes, PTEN, PDCD4 and E2F1, and TGF-βRII, in a cell-specific manner. Gain-of miR-21 function in MSMC and LSMC reduced TGF-β-induced expression of fibromodulin and TGF-β-induced factor (P < 0.05), and moderately altered the rate of cell growth and caspase-3/7 activity in these cells. We concluded that miR-21 is aberrantly expressed and hormonally regulated in leiomyomas where, through functional interaction with ovarian steroids and the TGF-β signaling pathway, either directly or indirectly regulates a number of genes whose products are critical in leiomyoma growth and regression as well as their potential cellular transformation.

Transforming growth interacting factor expression in leiomyoma compared with myometrium

OBJECTIVE

To investigate the expression of transforming growth interacting factor (TGIF), a Smad transcriptional corepressor, in leiomyoma and matched myometrial tissue samples and the effect of TGIF overexpression in myometrial cells.

DESIGN

Experimental study.

SETTING

Tertiary university hospital.

PATIENT(S)

Uterine leiomyoma and myometrial tissues from 16 patients.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The distribution of TGIF in leiomyoma and myometrial tissues by immunohistochemistry stain, mRNA, and protein expression levels by real-time quantitative polymerase chain-reaction (QPCR) and Western blot. Transcriptional regulation of TGIF in myometrial cells with overexpressed TGIF.

RESULT(S)

Although TGIF is present in the smooth muscle cells of the leiomyoma and the myometrium, it is not found in the extracellular matrix. The TGIF mRNA and protein expressions were statistically significantly higher in the leiomyoma compared with the matched, unaffected myometrial tissues in both phases of the menstrual cycle. There were no differences in mRNA or protein expression throughout the menstrual cycle. Overexpression of TGIF protein in myometrial cells statistically significantly suppressed up-regulation of plasminogen activator inhibitor (PAI-1) induced by TGF-beta1 treatment.

CONCLUSION(S)

Expression of TGIF is increased in leiomyoma compared with myometrium. This increase in TGIF expression is not affected by endogenous ovarian hormones. Thus, TGIF is a potential repressor of TGF-beta pathways in myometrial cells.

Genic expression of the uterine leiomyoma in reproductive-aged women after treatment with goserelin

OBJECTIVE

To identify the genes presenting different expression in uterine leiomyomas after goserelin treatment.

DESIGN

Retrospective analyses of tissue obtained in a prospective clinical study.

SETTING

School of Medicine of the University of São Paulo.

PATIENT(S)

30 nulliparous black women aged 20 to 45 years with symptoms of uterine leiomyoma, uterine volume over 300 mL, and surgical indications for myomectomy.

INTERVENTION(S)

Fifteen patients were given a monthly dose of 3.6 mg of goserelin over 3 months before surgery (group A), and 15 patients underwent surgery without any previous treatment (group B). Five random samples from each group were analyzed using the microarray technique with the Affymetrix platform (GeneChip Rat Genome 230 2.0 Array).

MAIN OUTCOME MEASURE(S)

Quantification of transcript expression levels of uterine fibroids in patients treated or not treated with goserelin.

RESULT(S)

Of the total of 47,000 sequences that were analyzed, representing approximately 38,500 human genes already characterized, we found a differential expression of 174 genes. Of these, 70 were up-regulated (33 genes with known function) and 104 were down-regulated (65 genes with known function) in samples from group A (treated) when compared with group B (nontreated).

CONCLUSION(S)

The genic expression of uterine leiomyomas changes in women who have had goserelin treatment when compared with nontreated patients.

Oviductal microsomal epoxide hydrolase (EPHX1) reduces reactive oxygen species (ROS) level and enhances preimplantation mouse embryo development

Somatic cell-embryo coculture enhances embryo development in vitro by producing embryotrophic factor(s) and/or removing harmful substances from the culture environment. Yet, the underlying molecular mechanisms on how somatic cells remove the toxicants from the culture medium remain largely unknown. By using suppression subtractive hybridization, we identified a number of mouse oviductal genes that were up-regulated when developing preimplantation embryos were present in the oviduct. Epoxide hydrolase 1, microsomal (Ephx1 previously known as mEH) was one of these genes. EPHX1 detoxifies genotoxic compounds and participates in the removal of reactive oxygen species (ROS). The transcript of Ephx1 increases in the oviductal epithelium at the estrus stage and in Day 3 of pregnancy as well as in the uterus of ovariectomized mice injected with estrogen or progesterone. Human oviductal epithelial cells OE-E6/E7 express EPHX1 and improve mouse embryo development in vitro. Addition of an EPHX1 inhibitor, cyclohexene oxide (CHO) or 1,1,1-trichloropropene 2,3-oxide (TCPO), to the culture medium increased intracellular and extracellular ROS levels of OE-E6/E7 cells and suppressed the beneficial effect of the cells on embryo development; CHO and TCPO at these concentrations had no adverse effect on OE-E6/E7 growth and embryo development in vitro. Taken together, EPHX1 in oviductal cells may enhance the development of cocultured embryos by protecting them from oxidative stress. Our result supports the notion that somatic cell coculture may enhance embryo development via removal of deleterious substances in the culture medium.

The expression and potential regulatory function of microRNAs in the pathogenesis of leiomyoma

Leiomyomas are benign uterine tumors considered to arise from transformation of myometrial cells. What initiates the conversion of myometrial cells into leiomyoma is unknown, however cytogenetic analysis often shows occurrence of nonrandom chromosomal abnormalities that may account for their establishment. It is clear that ovarian steroids are essential for leiomyoma growth, and local expression of many autocrine/paracrine mediators serving as key regulators of cell-cycle progression, cellular hypertrophy, extracellular matrix accumulation, and apoptosis appear to play central roles in this capacity. However, the stability of the expression of these genes represents the hallmarks of leiomyoma establishment, growth, and regression. With the emergence of microRNA (miRNA) as a key regulator of gene expression stability, in this review we present evidence for the expression and potential regulatory functions on miRNAs in leiomyoma with particular emphasis on the expression of their selective target genes whose products influence various cellular activities critical to pathogenesis of leiomyomas.

Potential link between estrogen receptor-alpha gene hypomethylation and uterine fibroid formation

Uterine leiomyomas are the most common uterine tumors in women. Estrogen receptor-alpha (ER-alpha) is more highly expressed in uterine leiomyomas than in normal myometrium, suggesting a link between uterine leiomyomas and ER-alpha expression. DNA methylation is an epigenetic mechanism of gene regulation and plays important roles in normal embryonic development and in disease progression including cancers. Here, we investigated the DNA methylation status of the ER-alpha promoter region (-1188 to +229 bp) in myometrium and leiomyoma. By sodium bisulfite sequencing, 49 CpG sites in the proximal promoter region of ER-alpha gene were shown to be unmethylated in both leiomyoma and normal myometrium. At seven CpG sites in the distal promoter region of the ER-alpha gene, there was a variation in DNA methylation status in myometrium and leiomyoma. Further analysis of the DNA methylation status by bisulfite restriction mapping among 11 paired samples of myometrium and leiomyoma indicated that CpG sites in the distal region of ER-alpha promoter are hypomethylated in leiomyomas of nine patients. In those patients, ER-alpha mRNA levels tended to be higher in the leiomyoma than in the myometrium. In conclusion, there was an aberrant DNA methylation status in the promoter region of ER-alpha gene in uterine leiomyoma, which may be associated with high ER-alpha mRNA expression.

Gene expression profiling of multiple leiomyomata uteri and matched normal tissue from a single patient

OBJECTIVE

To identify differentially expressed genes between fibroid and adjacent normal myometrium in an identical hormonal and genetic background.

DESIGN

Array analysis of three leiomyomata and matched adjacent normal myometrium in a single patient.

SETTING

University of Colorado Hospital.

PATIENT(S)

A single female undergoing medically indicated hysterectomy for symptomatic fibroids.

INTERVENTIONS(S)

mRNA isolation and microarray analysis, reverse-transcriptase polymerase chain reaction, Western blotting, and immunohistochemistry.

MAIN OUTCOME MEASURE(S)

Changes in mRNA and protein levels in leiomyomata and matched normal myometrium.

RESULT(S)

Expression of 197 genes was increased and 619 decreased significantly by at least twofold, in leiomyomata relative to normal myometrium. Expression profiles between tumors were similar and normal myometrial samples showed minimal variation. Changes in, and variation of, expression of selected genes were confirmed in additional normal and leiomyoma samples from multiple patients.

CONCLUSION(S)

Analysis of multiple tumors from a single patient confirmed changes in expression of genes described in previous, apparently disparate, studies, and identified novel targets. Gene expression profiles in leiomyomata are consistent with increased activation of mitogenic pathways and inhibition of apoptosis. Down-regulation of genes implicated in invasion and metastasis, of cancers, was observed in fibroids. This expression pattern may underlie the benign nature of uterine leiomyomata and may aid in the differential diagnosis of leiomyosarcoma.

Bioinformatics: microarray data clustering and functional classification

The human genome project has opened up a new page in scientific history. To this end, a variety of techniques such as microarray has evolved to monitor the transcript abundance for all of the organism's genes rapidly and efficiently. Behind the massive numbers produced by these techniques, which amount to hundreds of data points for thousands or tens of thousands of genes, there hides an immense amount of biological information. The importance of microarray data analysis lies in presenting functional annotations and classifications. The process of the functional classifications is conducted as follows. The first step is to cluster gene expression data. Cluster 3.0 and Java Treeview are widely used open-source programs to group together genes with similar pattern of expressions, and to provide a computational and graphical environment for analyzing data from DNA microarray experiments, or other genomic datasets. Clustered genes can later be decoded by Bulk Gene Searching Systems in Java (BGSSJ). BGSSJ is an XML-based Java application that systemizes lists of interesting genes and proteins for biological interpretation in the context of the gene ontology. Gene ontology gathers information for molecular function, biological processes, and cellular components with a number of different organisms. In this chapter, in terms of how to use Cluster 3.0 and Java Treeview for microarray data clustering, and BGSSJ for functional classification are explained in detail.

Differential expression of microRNAs in myometrium and leiomyomas and regulation by ovarian steroids

Given the emerging roles of microRNAs (miRNAs) as key regulator of mRNA stability we assessed their expression profile in paired myometrium and leiomyoma, their isolated smooth muscle cells (MSMC and LSMC), a spontaneously transformed leiomyoma smooth muscle cells (T-LSMC) and SK-LMS-1, a leiomyosarcoma cell line using microarray and real time PCR.Based on global normalization of expression values of 385 miRNAs and statistical analysis (anova), 91 miRNAs were expressed above the threshold levels in myometrium, with a progressive decline in numbers in leiomyomas, MSMC, LSMC, T-LSMC and SK-LMS-1 (P<0.05).We selected and validated the expression of miR-20a, miR-21, miR-26a, miR-18a, miR-206, miR-181a and miR-142–5p and found their differential expression in tissue and cell-specific manners (P<0.05).Treatments of MSMC and LSMC with 17β estradiol and medroxyprogesterone acetate (10⁻⁸M), or ICI-182780 and RU-486 (10⁻⁶M) resulted in differential regulation of these miRNAs (P<0.05).In conclusion, the expression of a number of miRNAs in myometrium and leiomyoma with their progressive aberrant from normal MSMC into LSMC, transformed and cancerous stage, suggests that miRNAs and their regulation by ovarian steroids play a key role in pathogenesis of leiomyoma through gene expression stability.

Genomic and proteomic profiling II: comparative assessment of gene expression profiles in leiomyomas, keloids, and surgically-induced scars

BACKGROUND

Leiomyoma have often been compared to keloids because of their fibrotic characteristic and higher rate of occurrence among African Americans as compared to other ethnic groups. To evaluate such a correlation at molecular level this study comparatively analyzed leiomyomas with keloids, surgical scars and peritoneal adhesions to identify genes that are either commonly and/or individually distinguish these fibrotic disorders despite differences in the nature of their development and growth.

METHODS

Microarray gene expression profiling and realtime PCR.

RESULTS

The analysis identified 3 to 12% of the genes on the arrays as differentially expressed among these tissues based on P ranking at greater than or equal to 0.005 followed by 2-fold cutoff change selection. Of these genes about 400 genes were identified as differentially expressed in leiomyomas as compared to keloids/incisional scars, and 85 genes as compared to peritoneal adhesions (greater than or equal to 0.01). Functional analysis indicated that the majority of these genes serve as regulators of cell growth (cell cycle/apoptosis), tissue turnover, transcription factors and signal transduction. Of these genes the expression of E2F1, RUNX3, EGR3, TBPIP, ECM-2, ESM1, THBS1, GAS1, ADAM17, CST6, FBLN5, and COL18A was confirmed in these tissues using quantitative realtime PCR based on low-density arrays.

CONCLUSION

the results indicated that the molecular feature of leiomyomas is comparable but may be under different tissue-specific regulatory control to those of keloids and differ at the levels rather than tissue-specific expression of selected number of genes functionally regulating cell growth and apoptosis, inflammation, angiogenesis and tissue turnover.

Genomic and proteomic profiling I: leiomyomas in African Americans and Caucasians

BACKGROUND

Clinical observations indicate that leiomyomas occur more frequently in African Americans compared to other ethnic groups with unknown etiology. To identify the molecular basis for the difference we compared leiomyomas form A. Americans with Caucasians using genomic and proteomic strategies.

METHODS

Microarray, realtime PCR, 2D-PAGE, mass spectrometry, Western blotting and immunohistochemistry.

RESULTS

Using Affymetrix U133A array and analysis based on P ranking (P < 0.01) 1470 genes were identified as differentially expressed in leiomyomas compared to myometrium regardless of ethnicity. Of these, 268 genes were either over-expressed (177 genes) or under-expressed (91 genes) based on P < 0.01 followed by 2-fold cutoff selection in leiomyomas of A. Americans as compared to Caucasians. Among them, the expression E2F1, RUNX3, EGR3, TBPIP, ECM2, ESM1, THBS1, GAS1, ADAM17, CST6, CST7, FBLN5, ICAM2, EDN1 and COL18 was validated using realtime PCR low-density arrays. 2D PAGE coupled with image analysis identified 332 protein spots of which the density/volume of 31 varied by greater than or equal to 1.5 fold in leiomyomas as compared to myometrium. The density/volume of 34 protein-spots varied by greater than or equal to 1.5 fold (26 increased and 8 decreased) in leiomyomas of A. Americans as compared to Caucasians. Tandem mass spectrometric analysis of 15 protein spots identified several proteins whose transcripts were also identified by microarray, including 14-3-3 beta and mimecan, whose expression was confirmed using western blotting and immunohistochemistry.

CONCLUSION

These findings imply that the level rather than the ethnic-specific expression of a number of genes and proteins may account for the difference between leiomyomas and possibly myometrium, in A. Americans and Caucasians. Further study using larger sample size is required to confirm these findings.

Human myometrium and leiomyomas express gonadotropin-releasing hormone 2 and gonadotropin-releasing hormone 2 receptor

OBJECTIVE

To determine the presence or absence of a second form of GnRH (GnRH2) and corresponding receptor (GnRHR2) in human uterine myometrium and leiomyomata.

DESIGN

Evaluation of human leiomyoma and patient-matched myometrium of differential mRNA and protein expression of GnRH2 and GnRHR2.

SETTING

University hospital.

PATIENT(S)

Eight women undergoing medically indicated hysterectomy for symptomatic fibroids.

INTERVENTION(S)

Microarray analysis, reverse-transcriptase polymerase chain reaction (RT-PCR), real-time RT-PCR, and immunohistochemistry.

MAIN OUTCOME MEASURE(S)

Expression of mRNA and protein in leiomyoma and patient-matched myometrium.

RESULT(S)

Microarray analysis demonstrated expression, and we confirmed the findings by RT-PCR. Real-time RT-PCR demonstrated equivalent expression of the genes in leiomyoma compared with patient-matched myometrium (0.99-fold for GnRH2 and 1.28-fold for GnRHR2). Immunohistochemistry confirmed the expression of GnRH2 protein in both leiomyoma and myometrium.

CONCLUSION(S)

A second form of GnRH and corresponding receptor exists in the fibroid and myometrium. We speculate that an autocrine loop exists. Our findings provide further evidence that GnRH agonists may interact directly with GnRH receptors present in uterine fibroids.

CCNs, fibulin-1C and S100A4 expression in leiomyoma and myometrium: inverse association with TGF-beta and regulation by TGF-beta in leiomyoma and myometrial smooth muscle cells

Connective tissue growth factor (CTGF; CCN2) is considered to serve as downstream midiator of TGF-beta action in tissue fibrosis. We tested this hypothesis in paired leiomyoma and myometrium by evaluating the expression of TGF-beta1/TGF-beta3 and CCN2, the other members of the CCN family, CCN3 and CCN4, as well as fibulin-1C and S100A4, calcium-binding proteins that interact with CCNs. The regulatory function of TGF-beta1 on the expression of these genes was further evaluated using leiomyoma (L) and myometrial (M) smooth muscle cells (SMC). Real-time PCR, Western blotting and immunohistochemistry revealed that leiomyomas and myometrium express CCNs, fibulin-1C and S100A4, whose levels of expression with the exception of fibulin-1C were lower in leiomyomas and inversely correlated with the expression of TGF-beta1 and TGF-beta3 (P<0.05). The expression of these genes was menstrual cycle-independent and GnRHa therapy increased the expression of CCN2 in leiomyomas, while inhibiting CCN3, CCN4 and S100A4 in myometrium (P<0.05). TGF-beta (2.5 ng/ml) in a time- and cell-dependent manner, and through MAPK and Smad pathways, differentially regulated the expression of these genes in LSMC and MSMC. We concluded that CCNs, fibulin-1C and S100A4 are expressed in leiomyomas/myometrium with relative expression levels inversely correlating with TGF-betas and influenced by GnRHa and TGF-beta regulatory actions. The results suggest that unlike other fibrotic disorders, CCN2 (CTGF), at least at tissue level, may not serve as a downstream mediator of TGF-beta action in leiomyomas.

In vitro culture significantly alters gene expression profiles and reduces differences between myometrial and fibroid smooth muscle cells

Cultured myometrial (M) and fibroid (F) smooth muscle cells (SMCs) have been widely used as a model for the study of F growth. The aim of this study was to compare gene expression profiles using microarrays between six paired M and F tissues from hysterectomy specimens, as well as cells isolated from the same tissues and cultured for up to three passages. A total of 2055 genes were differentially expressed by ANOVA between all experimental groups. Among them, 128 genes were found to be statistically different between M and F tissues. More than 1100 genes were significantly changed between tissues and cultured cells, with 648 genes common between both M and F cells at P0 and P3. Expression profiles of six genes including estrogen receptor-alpha (ERalpha) and progesterone receptor (PR) were also validated using real-time PCR. These data demonstrate that large changes occur in SMC gene expression in culture, reducing differences between M and F cells. They also show that ERalpha and PR levels are reduced in cells compared with whole tissue. These results indicate that although M and F cell cultures provide an important tool to study these tumours, in vitro studies must be carefully planned and evaluated to provide meaningful results.

The expression of Abl interactor 2 in leiomyoma and myometrium and regulation by GnRH analogue and transforming growth factor-β

BACKGROUND

Abelson (Abl) interactor 2 (Abi-2) has been considered as a key regulator of cell/tissue structural organization and is differentially expressed in leiomyomas. The objective of this study was to evaluate the expression of Abi-2 in leiomyoma/myometrium during the menstrual cycle and following GnRH analogue (GnRHa) therapy, as well as regulation by transforming growth factor (TGF)-beta1 in leiomyoma and myometrial smooth muscle cells (LSMC and MSMC).

METHODS

We used real-time PCR, Western blotting and immunohistochemistry to determine the expression of Abi-2 in paired leiomyoma and myometrium (n = 27) from proliferative (n = 8) and secretory (n = 12) phases of the menstrual cycle and from patients who received GnRHa therapy (n = 7). Time-dependent action of TGF-beta1 (2.5 ng/ml) and GnRHa (0.1 microM) on Abi-2 expression was determined in LSMC and MSMC.

RESULTS

Leiomyomas express elevated levels of Abi-2 as compared with myometrium from the proliferative but not the secretory phase of the menstrual cycle, with a significant reduction following GnRHa therapy (P < 0.05). Western blotting showed a similar trend in Abi-2 protein expression in leiomyoma/myometrial tissue extracts, which was immunolocalized in LSMC and MSMC, connective tissue fibroblasts and arterial walls. The expression of Abi-2 in LSMC and MSMC was increased by TGF-beta1 (2.5 ng/ml) and was inhibited by GnRHa (0.1 microM) in a time- and cell-dependent manner, and pretreatment with Smad3 SiRNA and U0126, an MEK-1/2 inhibitor, respectively, reversed their actions.

CONCLUSION

Based on the menstrual cycle-dependent expression, the influence of GnRHa therapy, and regulation by TGF-beta in LSMC/MSMC, we conclude that Abi-2 may have a key regulatory function in leiomyomas cellular/tissue structural organization during growth and regression.

Fibromodulin is expressed in leiomyoma and myometrium and regulated by gonadotropin-releasing hormone analogue therapy and TGF-β through Smad and MAPK-mediated signalling

Microarray gene expression profiling revealed fibromodulin (FMOD) is among differentially expressed genes in leiomyoma (L) and myometrium. Using realtime PCR, western blotting and immunohistochemistry, we validated the expression of FMOD in paired leiomyoma and myometrium (N = 20) during the menstrual cycle, from women who received gonadotropin-releasing hormone analogue (GnRHa) therapy (N = 7) and in leiomyoma and myometrial (M) smooth muscle cells (SMC) due to transforming growth factor (TGF)-beta and GnRHa treatment. The results indicated that FMOD is expressed at significantly higher levels in leiomyoma as compared to myometrium from proliferative phase (two- to three-folds; P < 0.05), but not the secretory phase of the menstrual cycle, whereas GnRHa therapy reduced FMOD expression to levels detected in myometrium from proliferative phase (P = 0.05). By using western blotting and immunohistochemistry immunoreactive FMOD was detected in leiomyoma and myometrial tissue-extract and in LSMC and MSMC, connective tissue fibroblasts and arterial walls. In a time- and cell-dependent manner, TGF-beta1 (2.5 ng/ml) increased the expression of FMOD in MSMC, whereas GnRHa (0.1 microM) inhibited that in MSMC and LSMC (P < 0.05). The effect of TGF-beta and GnRHa on FMOD expression was reversed following pretreatment of LSMC and MSMC with Smad3 SiRNA and U0126 (MEK1/2 inhibitor), respectively. In summary, menstrual cycle-dependent expression of FMOD and suppression following GnRHa therapy in leiomyoma and myometrium, as well as differential regulation by TGF-beta and GnRHa in vitro suggests that FMOD, a key regulator of tissue organization, plays a critical role in leiomyoma fibrotic characteristics.

Gene expression profiling of leiomyoma and myometrial smooth muscle cells in response to transforming growth factor-beta

Altered expression of the TGF-beta system is recognized to play a central role in various fibrotic disorders, including leiomyoma. In this study we performed microarray analysis to characterize the gene expression profile of leiomyoma and matched myometrial smooth muscle cells (LSMC and MSMC, respectively) in response to the time-dependent action of TGF-beta and, after pretreatment with TGF-beta type II receptor (TGF-beta RII) antisense oligomer-blocking/reducing TGF-beta autocrine/paracrine actions. Unsupervised and supervised assessments of the gene expression values with a false discovery rate selected at P < or = 0.001 identified 310 genes as differentially expressed and regulated in LSMC and MSMC in a cell- and time-dependent manner by TGF-beta. Pretreatment with TGF-beta RII antisense resulted in changes in the expression of many of the 310 genes regulated by TGF-beta, with 54 genes displaying a response to TGF-beta treatment. Comparative analysis of the gene expression profile in TGF-beta RII antisense- and GnRH analog-treated cells indicated that these treatments target the expression of 222 genes in a cell-specific manner. Gene ontology assigned these genes functions as cell cycle regulators, transcription factors, signal transducers, tissue turnover, and apoptosis. We validated the expression and TGF-beta time-dependent regulation of IL-11, TGF-beta-induced factor, TGF-beta-inducible early gene response, early growth response 3, CITED2 (cAMP response element binding protein-binding protein/p300-interacting transactivator with ED-rich tail), Nur77, Runx1, Runx2, p27, p57, growth arrest-specific 1, and G protein-coupled receptor kinase 5 in LSMC and MSMC using real-time PCR. Together, the results provide the first comprehensive assessment of the LSMC and MSMC molecular environment targeted by autocrine/paracrine action of TGF-beta, highlighting potential involvement of specific genes whose products may influence the outcome of leiomyoma growth and fibrotic characteristics by regulating inflammatory response, cell growth, apoptosis, and tissue remodeling.