leptin and Leiomyoma

To test if treatment with GnRH analogue, which leads to a significant reduction in myoma volume, changes expression of leptin genes and gene coding leptin receptor isoforms in uterine myomas and in the surrounding unaltered myometrium.. Using RT-PCR, expression of leptin genes and leptin receptor genes was studied in myomas and in the surrounding myometrium in women with uterine myomas, untreated or treated with GnRH analogue. In the randomly selected cases presence of leptin protein and of leptin receptor proteins was examined also by Western blotting.. Expression of leptin genes was demonstrated both in myomas and in the surrounding myometrium, and a similar pattern of expression was found for leptin receptor isoforms. The results of RT-PCR were confirmed by Western blotting, which documented the identical distribution of leptin proteins and leptin receptor proteins in studied tissues. Treatment with GnRH analogue had no effect on the expression pattern of studied genes.. The results of the present study on the administration of GnRH analogue to females with myomas suggest that no direct or immediate inter-relationship exists between expression of leptin genes in uterine myomas on one hand and estrogen, progesterone and leptin levels in the blood on the other. Expression seems to be of a more durable nature but factors that induce such expression remain unknown.

Topics: Adult; Blotting, Western; Case-Control Studies; DNA Primers; Female; Gene Expression Regulation, Neoplastic; Gonadotropin-Releasing Hormone; Humans; Leiomyoma; Leptin; Middle Aged; Myoma; Myometrium; Receptors, Cell Surface; Receptors, Leptin; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Uterine Neoplasms

The purpose of the present study was to investigate changes in serum leptin levels during GnRH agonist therapy. Twenty regularly menstruating women with uterine leiomyomas were enrolled. These subjects were given GnRH agonist (leuprorelin acetate, 3.75 mg) monthly for 4 months. Serum leptin and estradiol (E2) levels were measured at the two time points of day 1 or 2 of the menstrual cycle and the end of GnRH agonist therapy. Weight, total body fat mass, percentage of body fat, and total body lean mass were measured by whole body scanning with dual-energy X-ray absorptiometry. The ratio of serum leptin levels to total body fat mass (leptin-fat mass ratio), and the ratio of serum leptin levels to total body lean mass (leptin-lean mass ratio) were calculated. All subjects became amenorrheic after the initial administration of GnRH agonist. Baseline E2 levels were 45.4 +/- 21.0 pg/mL, which significantly decreased after GnRH agonist therapy (13.3 +/- 4.2 pg/mL, p<0.01). Baseline leptin levels were 8.7 +/- 8.1 ng/mL, which did not differ from the values after 4 months of GnRH agonist administration (8.9 +/- 6.8 ng/mL). Total body fat mass significantly increased from 20.0 +/- 10.4 to 21.0 +/- 9.4 kg (p<0.05), while total body lean mass significantly decreased (34.5 +/- 4.2 kg to 33.3 +/- 3.9 kg, p<0.01). However, leptin-fat mass ratio after GnRH agonist therapy did not differ from the baseline values (0.39 +/- 0.16 ng/mL/kg vs 0.38 +/- 0.16 ng/mL/kg). Hypogonadism does not have a major impact on circulating leptin levels.

Topics: Adult; Antineoplastic Agents, Hormonal; Body Composition; Estradiol; Female; Gonadotropin-Releasing Hormone; Humans; Leiomyoma; Leptin; Leuprolide; Longitudinal Studies; Middle Aged; Uterine Neoplasms

Uterine leiomyomas are the most common benign tumors of the female reproductive system. Obese individuals have a higher burden of uterine leiomyoma, yet the mechanism relating obesity and leiomyoma development remains unknown. In this study, we observe the effect of adipocyte coculture and leptin treatment on human myometrium and leiomyoma cells. We isolated primary leiomyoma and myometrium cells from hysterectomy or myomectomy patients. Protein expression levels of phosphorylated ERK1/2/total ERK1/2, phosphorylated STAT3/total STAT3, and phosphorylated AKT1/2/3/total AKT1/2/3 were quantified using immunoblotting in immortalized and primary leiomyoma and myometrial cells cocultured with human adipocytes and treated with leptin. An enzyme-linked immunosorbent assay (ELISA) was used to assess pro-inflammatory, fibrotic, and angiogenic factors in immortalized human myometrium and leiomyoma cells treated with leptin. The effects of STAT3, ERK, and AKT inhibitors were assessed in leiomyoma cell lines additionally cultured with adipocytes. Adipocyte coculture and leptin treatment increases the expression of JAK2/STAT3, MAPK/ERK, and PI3K/AKT signaling while inhibitors suppressed this effect. Leptin induces a tumor-friendly microenvironment through upregulation of pro-inflammatory (IFNγ, IL-8, IL-6, GM-CSF, MCP-1, and TNF-α), fibrotic (TGF-β1, TGF-β2, and TGF-β3), and angiogenic (VEGF-A, HGF, and Follistatin) factors in human leiomyoma cells. Furthermore, adipocyte coculture and leptin treatment increases leiomyoma cells growth through activation of MAPK/ERK, JAK2/STAT3, and PI3k/AKT signaling pathways. Finally, STAT3, ERK, and AKT inhibitor treatment suppressed PCNA, TNF-α, TGF-β3, and VEGF-A intracellular staining intensity in both adipocyte coculture and leptin treated leiomyoma cells. These findings suggest that, in obese women, adipocyte secreted hormone or adipocytes may contribute to leiomyoma development and growth by activating leptin receptor signaling pathways.

Topics: Adipocytes; Adipokines; Female; Humans; Leiomyoma; Leptin; Obesity; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Transforming Growth Factor beta3; Tumor Microenvironment; Tumor Necrosis Factor-alpha; Uterine Neoplasms; Vascular Endothelial Growth Factor A

Leiomyomas (fibroids) are monoclonal tumors in which myometrial stem cells (MSCs) turn tumorigenic after mutation, abnormal methylation, or aberrant signaling. Several factors contribute to metabolic dysfunction in obesity, including abnormal cellular proliferation, oxidative stress, and DNA damage. The present study aims to determine how adipocytes and adipocyte-secreted factors affect changes in MSCs in a manner that promotes the growth of uterine leiomyomas. Myometrial stem cells were isolated from the uteri of patients by fluorescence-activated cell sorting (FACS) using CD44/Stro1 antibodies. Enzyme-linked immunosorbent assay (ELISA), Western blot, and immunocytochemistry assays were performed on human adipocytes (SW872) co-cultured with MSCs and treated with leptin or adiponectin to examine the effects of proliferation, extracellular matrix (ECM) deposition, oxidative damage, and DNA damage. Co-culture with SW872 increased MSC proliferation compared to MSC culture alone, according to 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) results. The expressions of PCNA and COL1A increased significantly with SW872 co-culture. In addition, the expression of these markers was increased after leptin treatment and decreased after adiponectin treatment in MSCs. The Wnt/β-catenin and TGF-β/SMAD signaling pathways promote proliferation and ECM deposition in uterine leiomyomas. The expression of Wnt4, β-catenin, TGFβ3, and pSMAD2/3 of MSCs was increased when co-cultured with adipocytes. We found that the co-culture of MSCs with adipocytes resulted in increased NOX4 expression, reactive oxygen species production, and γ-H2AX expression. Leptin acts by binding to its receptor (LEP-R), leading to signal transduction, resulting in the transcription of genes involved in cellular proliferation, angiogenesis, and glycolysis. In MSCs, co-culture with adipocytes increased the expression of LEP-R, pSTAT3/STAT3, and pERK1/2/ERK/12. Based on the above results, we suggest that obesity may mediate MSC initiation of tumorigenesis, resulting in leiomyomas.

Topics: Adiponectin; beta Catenin; DNA Damage; Humans; Leiomyoma; Leptin; Obesity; Oxidative Stress

To investigate the molecular effects of leptin on uterine leiomyoma cells.. Experimental study using in vitro culture of immortalized human leiomyoma (HuLM) cells.. Academic university center.. Women with uterine fibroids who underwent a hysterectomy or myomectomy.. Administration of human recombinant leptin to the media of cultured HuLM cells separately or in combination with pharmacologic Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) or mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) inhibitors.. We examined HuLM tissues and cells for the expression of the leptin receptor, termed OB-R. Cellular proliferation was measured at 6, 24, and 48 hours using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay. Protein expression levels of proliferating cell nuclear antigen, collagen 1, phosphorylated STAT3/total STAT3, and phosphorylated ERK1/2 and total ERK1/2 were quantified using immunoblotting. Pharmacologic inhibitors were employed to further assess the role of the JAK2/STAT3 and MAPK/ERK pathways in the proliferative response.. The presence of OB-R was confirmed in clinical leiomyoma and myometrial tissue obtained from 3 separate human subjects using immunofluorescence staining, and the expression of OB-R in HuLM cells was identified using immunoblotting. There was no significant difference in the expression of the leptin receptor in the myometrium compared with that in the leiomyoma tissue. Leptin stimulated cell proliferation and extracellular matrix (ECM) deposition at 24 hours after treatment. Pretreatment with a JAK2/STAT3 inhibitor attenuated ECM deposition, and pretreatment with a MAPK/ERK inhibitor significantly decreased leptin's stimulatory effect on cell proliferation and ECM deposition.. Leptin induces a proliferative response and ECM deposition in HuLM cells. These findings suggest that leptin, acting through the JAK2/STAT3 and MAPK/ERK pathways, is involved in the development of uterine leiomyomas, which may partly explain their increased incidence in obese women.

Topics: Cell Proliferation; Extracellular Matrix; Female; Humans; Janus Kinase 2; Leiomyoma; Leptin; MAP Kinase Signaling System; Mitogen-Activated Protein Kinases; Receptors, Leptin; STAT3 Transcription Factor

The aim of this study was to analyse the frequencies of genotypes and alleles of Single Nucleotide Polymorphism (SNP) -2548 G/A (rs12112075) of leptin gene (LEP) and an attempt to evaluate the effect this DNA marker has on endometrial cancer (EC) and uterine leiomyomas (UL).. The study comprised 120 patients treated for endometrial cancer and 90 patients treated for uterine leiomyomas. 90 disease-free individuals were used as controls. In total, 300 patients were investigated in this research.. In this paper we have demonstrated that genotype AG of SNP -2548 G/A of LEP may reduce the risk of developing endometrial cancer, whereas allele A itself may be a risk factor of this malignancy. No association was found between the studied polymorphism and uterine leiomyomas.. -2548 G/A SNP of LEP may play a significant role in the development of EC, however, uterine leiomyomas are not associated with this DNA marker.

Topics: Alleles; Body Mass Index; Case-Control Studies; Endometrial Neoplasms; Female; Genetic Markers; Genotype; Humans; Leiomyoma; Leptin; Middle Aged; Obesity; Polymorphism, Restriction Fragment Length; Polymorphism, Single Nucleotide; Risk Factors; Uterine Neoplasms

This study was aimed to understand expressions of the visfatin, leptin, stromal cell derived factor (SDF)-1α, endothelial nitric oxide synthase (eNOS), and vascular endothelial growth factor (VEGF) in human uterine leiomyomas (UL) and normal myometrium.. This study investigated expression of visfatin, leptin, SDF-1α, eNOS and VEGF in 23 uterine leiomyoma patients and 10 normal myometrium by RT-PCR and western blot. Messenger RNA transcripts of SDF-1α, eNOS, VEGF and hypoxia inducible factor-1α (HIF-1α) were analyzed according to the size of UL by real-time PCR.. There were no significant differences in expressions of visfatin and leptin between UL compared with normal myometrium. However, expressions of eNOS, SDF-1α and VEGF were significantly higher in both intramural and subserosal UL compared with normal myometrium. The expression of SDF1-α was significantly increased in small UL (<5 cm) compared to the large UL (≥5 cm), whereas the expressions of eNOS, VEGF and HIF-1α were higher in large UL than small UL.. This study shows that expression of SDF-1α, eNOS and VEGF were significantly higher in UL than myometrium with a different expression pattern according to the size of UL. However, expressions of visfatin and leptin had no significant differences between the two groups.

Topics: Adult; Chemokine CXCL12; Female; Humans; Leiomyoma; Leptin; Middle Aged; Myometrium; Nicotinamide Phosphoribosyltransferase; Nitric Oxide Synthase Type III; Uterine Neoplasms; Vascular Endothelial Growth Factor A

The purpose of this study was to examine the influence of leptin in women with uterine myoma.. In this study, 38 women with myoma uteri and 30 normal women who applied to the Dr Zekai Tahir Burak Woman Health Research and Education Hospital's gynecology clinic were enrolled. Uterine leiomyomas were proved by pathology postoperatively. In all subjects, FSH, LH, E2, prolactin, hemoglobin, hematocrit, blood urea nitrogen, creatinine, fasting glucose, CA125, and leptin were examined, and body mass index (BMI) was calculated. Data were analyzed by Student's t test and Mann-Whitney U test.. Although leptin level was higher in the myomatic women (5.73 +/- 4.08 ng/mL) than in the normal women, there was no statistically significant difference (p = 0.303). Also, no statistical difference in the ratios of leptin/BMI was found in both groups. A significant correlation was found between high E2 level and myoma uteri (p = 0.021). Hemoglobin levels were significantly lower in the myomatic women (p = 0.044). When we compared the leptin levels according to BMI, leptin levels were higher in patients who had BMI > 30 (p = 0.02).. We did not find any significant difference in serum leptin levels between the two groups. But leptin may have an indirect role in the pathogenesis of uterine leiomyoma. So further research is needed to reveal the role of leptin in myoma uteri pathogenesis.

Topics: Adult; Body Mass Index; CA-125 Antigen; Female; Hemoglobins; Hormones; Humans; Leiomyoma; Leptin; Middle Aged; Uterine Neoplasms

In vitro and in vivo studies have linked mast cell (MC) degranulation and activation with angiogenesis and neovascularization. This assumption is partially supported by the close anatomical association between MC and the vasculature and the recruitment of these cells during tumor growth. The aim of this study was to correlate the extent of angiogenesis with the number of MC expressing tryptase and leptin in human leiomyomas.. Tissues from human leiomyomas and control specimens were investigated immunohistochemically, using murine monoclonal antibodies against the endothelial cell marker CD31, leptin, and the MC marker tryptase.. Angiogenesis, measured as microvessel counts, was highly correlated with MC tryptase- and leptin-positive cell counts.. These data suggest that angiogenesis in leiomyomas is correlated to expression of tryptase in MC granules and provide for the first time evidence of a putative role of leptin, also contained in MC secretory granules, in MC-dependent angiogenesis.

Topics: Cell Count; Cell Degranulation; Female; Humans; Leiomyoma; Leptin; Mast Cells; Neovascularization, Pathologic; Tryptases; Uterine Neoplasms

Examination of the potential role of leptin in the development of uterine myomas. Expression of the leptin gene and leptin receptor gene was tested in the myometrium of healthy women, and in myomas and the surrounding myometrium of women with benign tumors.. Using RT-PCR, expression of the leptin gene and leptin receptor gene were studied in myomas and in the surrounding myometrium in 30 women with uterine myomas at various phases of the menstrual cycle, and in the myometrium of ten women in a control group. Presence of leptin gene proteins and leptin receptor gene proteins in the women was also examined by Western blotting.. Using RT-PCR, expression of the leptin gene was demonstrated both in myomas and in the surrounding myometrium. In contrast, expression of the gene could not be detected in the myometrium of healthy women. The results were confirmed by Western blotting, which documented the identical distribution of leptin proteins and leptin receptor proteins in studied tissues.. Demonstration of the expression of leptin genes and leptin proteins in uterine myomas and in the surrounding myometrium, and their absence in the myometrium of healthy women suggests the involvement of leptin in the development of uterine myomas.

Topics: Adult; Aged; Case-Control Studies; DNA Primers; Female; Gene Expression Regulation, Neoplastic; Humans; Leiomyoma; Leptin; Middle Aged; Myometrium; Receptors, Cell Surface; Receptors, Leptin; Reverse Transcriptase Polymerase Chain Reaction; Uterine Neoplasms

To analyze the possible involvement of leptin in uterine leiomyomas.. Serum leptin levels, determined by radioimmunoassay, were compared in myomatic (n = 50) and the normal (n = 50) women.. A significant correlation was found between serum leptin levels and body mass index in both the myomatic women (r = 0.76, p < 0.001) and the normal women (r = 0.56, p < 0.001). Serum leptin levels in the myomatic women (9.3 +/- 0.6 ng/mL) were significantly lower (p < 0.001) than those in the normal women (13.6 +/- 1.2 ng/mL). In addition, the ratios of serum leptin levels/body mass index in the myomatic women (0.38 +/- 0.02) were significantly lower than those in the normal women (0.57 +/- 0.04) (p < 0.001). A significant correlation was found between the ratios of serum leptin levels/body mass index and body mass index (r = 0.59, p < 0.001) in the normal women, but not in the myomatic women (r = 0.27, p = 0.061).. The lower plasma leptin levels observed in the women with myomas were independent of body mass index, and unlike the normal women there was no significant up-regulation of leptin production in response to increased adiposity.

Topics: Adult; Body Mass Index; Body Weight; Female; Humans; Leiomyoma; Leptin; Middle Aged; Radioimmunoassay; Uterine Neoplasms

The purpose of this study was to examine the influence of luteinizing hormone-releasing hormone analog goserelin on serum leptin and body composition in women with solitary uterine myoma.. Fifteen women who were regularly menstruating and not obese were included. In all subjects, serum concentrations of leptin, insulin, testosterone, progesterone, and estradiol and body mass index and waist-to-hip ratio were measured before and after 4, 8, and 12 weeks of treatment with goserelin (3.6 mg every 4 weeks). Fat mass and lean body mass were measured by dual energy radiographic densitometry at baseline and after 12 weeks of therapy. Data were analyzed by multiple way analysis of variance and both simple and multiple regression.. The treatment caused a significant regression of myoma. Body weight, fat, and lean mass were unchanged. No changes in plasma leptin (even after correction for fat mass) were noted during the treatment. Plasma estradiol decreased below castrate levels. Plasma progesterone decreased significantly, and testosterone tended to decline during the study. At baseline a highly significant positive correlation was found between serum leptin and fat mass. In a multiple regression analysis, neither the change in fat mass nor any of the hormonal parameters explained the significant portion of variance of plasma leptin during the treatment.. Pharmacologic gonadectomy does not influence plasma leptin concentrations in women if body fat mass is unchanged.

Topics: Adipose Tissue; Adult; Antineoplastic Agents, Hormonal; Body Composition; Estradiol; Female; Gonadotropin-Releasing Hormone; Goserelin; Humans; Leiomyoma; Leptin; Middle Aged; Progesterone; Testosterone; Uterine Neoplasms

To investigate the effects of total abdominal hysterectomy on circulating leptin levels, 16 pre- and 8 postmenopausal patients with uterine leiomyoma or carcinoma in situ of the uterine cervix were enrolled. Serum levels of leptin and fasting blood sugar (FBS) were determined before (day -7) and after surgery (day +1 and +7). Body mass index (BMI) was recorded at day -7 and +7. Anesthesia duration, surgical duration, hematology, and blood loss during surgery were recorded. Relations of these variables to serum leptin levels were investigated. Serum leptin levels rose from 7.3+/-4.7 ng/mL to 9.3+/-5.8 ng/mL at day +1 (P < 0.01), then decreased to 4.9+/-3.0 ng/mL at day +7 (P < 0.05 vs. values at day -7 and +1). FBS levels also rose from 89.4+/-7.5 mg/dL to 119.3+/-24.0 mg/dL (P < 0.01), then returned to normal at day +7 (96.2+/-9.0 mg/dL). However, there was no significant correlation observed between FBS and leptin levels at each time point (r < or = 0.22). BMI decreased from 22.7+/-3.0 kg/m2 to 21.7+/-2.9 kg/m2 at day +7 (P < 0.001). At day -7 and +7, leptin levels were positively correlatd with BMI (r = 0.79, P < 0.001 and r = 0.71, P < 0.001, respectively). Circulating leptin levels were increased on day one after total abdominal hysterectomy.

Topics: Adult; Blood Glucose; Body Mass Index; Carcinoma in Situ; Female; Humans; Hysterectomy; Leiomyoma; Leptin; Middle Aged; Postmenopause; Premenopause; Uterine Cervical Neoplasms; Uterine Neoplasms

Leptin is important in the regulation of fat mass and body weight. Adipose tissue not only secretes leptin but also serves as a site of action for leptin. This study was designed to examine the relationships among tissue expression of leptin receptors, serum leptin, and body mass index.. Omental adipose tissue and fasting blood samples were obtained from 57 nondiabetic women who underwent surgery for either myoma of the uterus or ovarian cyst. Tissue RNA was extracted using Trizol reagent and serum leptin concentrations were determined with commercial kits. The leptin receptor isoforms in tissues were quantified using real-time Taqman technology.. Three leptin receptor isoforms, Ob-Rb, HuB219.1, and HuB219.3, were found in human omental adipose tissue. The amounts of HuB219.1 and HuB219.3 mRNA relative to that of Ob-Rb were 1314.2 and 16.7, respectively. Higher body mass index was significantly correlated with an increase in serum leptin concentration and a decrease in leptin receptor HuB219.1 isoform in omental fat, even after adjustment for age and menopausal status. There was no direct association between serum leptin concentration and tissue HuB219.1 mRNA level.. HuB219.1 is the major isoform of leptin receptor expressed in human omental adipose tissue. Our findings suggest that the shorter leptin receptor isoforms in human omental adipose tissue might play an important role in body weight control. Further studies on the inter-relationship between leptin concentrations and multiple leptin receptor isoforms are needed to elucidate the exact mechanism of obesity.

Topics: Adipose Tissue; Body Mass Index; Carrier Proteins; Female; Humans; Leiomyoma; Leptin; Omentum; Ovarian Cysts; Protein Isoforms; Receptors, Cell Surface; Receptors, Leptin; Uterine Neoplasms