Expression of sex hormone-binding globulin, oxytocin receptor, caveolin-1 and p21 in leiomyoma

Simvastatin reduces plasma membrane caveolae and caveolin-1 in uterine leiomyomas

AIMS

Uterine leiomyomas, or fibroids, are estrogen dependent benign tumor in women, however, they have limited treatment options. Simvastatin, a drug commonly used to treat high cholesterol. Recently we demonstrated that simvastatin alters estrogen signaling by reducing the expression and trafficking of the estrogen receptor-α (ER-α) in human uterine leiomyoma cells. Caveolae are invaginations of the plasma membrane where ER-α is known to localize and directly interacts with the caveolar protein caveolin-1 (CAV1). This study examines the effects of simvastatin on plasma membrane caveolae and the expression and palmitoylation of CAV1 in human leiomyomas which may influence ER-α signaling.

MAIN METHODS

We performed in vitro experiments using primary and immortalized human uterine leiomyoma cells. The caveolae were quantified using transmission electron microscopy. Additionally, we examined the impact of simvastatin treatment (40 mg orally per day for 12 weeks) on human leiomyoma tissue obtained from a randomized controlled trial. The CAV1 protein and mRNA levels were determined using quantitative real-time polymerase chain reactions, western blotting, and immunofluorescence analyses.

KEY FINDINGS

Simvastatin decreased the number of caveolae in primary leiomyoma cells and reduced CAV1 abundance in whole cells and remarkably the plasma protein fraction. It also decreased CAV1 palmitoylation, a post-translational modification associated with CAV1 activation. The effects of simvastatin on CAV1 were recapitulated in human leiomyoma tissue samples.

SIGNIFICANCE

Our results identify caveolae and CAV1 as novel targets of simvastatin which may contribute to the recently described effects of simvastatin on ER-α signaling and plasma membrane trafficking.

Pathogenesis, diagnosis and treatment of uterine lipoleiomyoma: A review

Uterine lipoleiomyomas are variants of uterine leiomyomas and are characterized by progressive enlargement that can occur even after menopause. These tumors can produce serious clinical symptoms and are difficult to diagnosis preoperatively. The growth rate of uterine lipoleiomyomas after menopause is comparatively higher than that of conventional uterine leiomyomas, and lipoleiomyosarcomas as well as tumor-to-tumor metastasis associated with lipoleiomyomas have been reported. However, detailed histogenic mechanisms of the tumor remain unclear. Surgical treatments are the current choice for the management of lipoleiomyomas. The purpose of this review is to promote greater awareness of lipoleiomyoma characteristics with a focus on histogenesis, diagnosis, and treatment. We performed an exhaustive literature review and have summarized the available data. We assessed the interpretation of auxiliary examinations to help physicians in making an early accurate diagnosis of the disease and to help with treatment decision-making, particularly regarding whether surgery should be performed or avoided.

Oxytocin selectively reduces blood flow in uterine fibroids without an effect on myometrial blood flow: a dynamic contrast enhanced MRI evaluation

INTRODUCTION

Uterine fibroids are the most common benign neoplasms in women. The administration of intravenous oxytocin is known to increase the efficacy of a non-invasive thermal ablation method (MR-HIFU) for treating fibroids. However, it is not known whether this phenomenon is caused by the effect of the oxytocin on the myometrium or the fibroid itself. The objective of this study was to evaluate the influence of oxytocin on the blood flow of fibroids, myometrium and skeletal muscle using a quantitative perfusion MRI technique.

MATERIALS AND METHODS

17 premenopausal women with fibroids considered to be treated with MR-HIFU and 11 women with no fibroids were enrolled in the study. An extended MRI protocol of the pelvis was acquired for each subject. Later another MRI scan was performed with continuous intravenous infusion of oxytocin. The effect of oxytocin was analyzed from quantitative perfusion imaging. The study was registered in clinicaltrials.gov NCT03937401.

RESULTS

Oxytocin decreased the blood flow of each fibroid; the median blood flow of fibroid was 39.9 ml/100 g tissue/min without and 3.5 mL/100 g/min with oxytocin (p ≤ 0.0001). Oxytocin did not affect the blood flow of the myometrium in either group. Oxytocin increased the blood flow of the skeletal muscle in both groups (p = 0.04).

CONCLUSION

Oxytocin is effective in decreasing the blood flow in fibroids while having minor or no effect on the blood flow of normal myometrium. Routine use of oxytocin in HIFU therapy may make the therapy suitable to a larger group of women in a safe manner.

Perioperative Interventions to Minimize Blood Loss at the Time of Hysterectomy for Uterine Leiomyomas: A Systematic Review and Meta-analysis

STUDY OBJECTIVE

Hysterectomy for uterine leiomyoma(s) is associated with significant morbidity including blood loss. A systematic review and meta-analysis was conducted to identify nonhormonal interventions, perioperative surgical interventions, and devices to minimize blood loss at the time of hysterectomy for leiomyoma.

DATA SOURCES

Librarian-led search of Embase, MEDLINE, Web of Science, Scopus, Cumulative Index to Nursing and Allied Health Literature, and Cochrane databases from 1946 to 2018 with hand-guided updates.

METHODS OF STUDY SELECTION

Included studies reported on keywords of hysterectomy, leiomyoma, and operative blood loss/postoperative hemorrhage/uterine bleeding/metrorrhagia/hematoma. The review excluded a comparison of route of hysterectomy, morcellation, vaginal cuff closure, hormonal medications, vessel sealing devices for vaginal hysterectomy, and case series with <10 patients.

TABULATION, INTEGRATION, AND RESULTS

Surgical blood loss, postoperative hemoglobin (Hb) drop, hemorrhage, transfusion, and major and minor complications were analyzed and aggregated in meta-analyses for comparable studies in each category. A total of 2016 unique studies were identified, 33 of which met the inclusion criteria, and 22 were used for quantitative synthesis. The perioperative use of misoprostol in abdominal hysterectomy (AH) was associated with a lower postoperative Hb drop (0.59 g/dL; 95% confidence interval [CI], 0.39-0.79; p < .01) and blood loss (-96.43 mL; 95% CI, -153.52 to -39.34; p < .01) compared with placebo. Securing the uterine vessels at their origin in laparoscopic hysterectomy (LH) was associated with decreased intraoperative blood loss (-69.07 mL; 95% CI, -135.20 to -2.95; p = .04) but no significant change in postoperative Hb (0.24 g/dL; 95% CI, -0.31 to 0.78; p = .39) compared with securing them by the uterine isthmus. Uterine artery ligation in LH before dissecting the ovarian/utero-ovarian vessels was associated with lower surgical blood loss compared with standard ligation (-27.72 mL; 95% CI, -35.07 to -20.38; p < .01). The postoperative Hb drop was not significantly different with a bipolar electrosurgical device versus suturing in AH (0.26 g/dL; 95% CI, -0.19 to 0.71; p = .26). There was no significant difference between an electrosurgical bipolar vessel sealer (EBVS) and conventional bipolar electrosurgical devices in the Hb drop (0.02 g/dL; 95% CI, -0.15 to 0.20; p = .79) or blood loss (-50.88 mL; 95% CI, -106.44 to 4.68; p = .07) in LH. Blood loss in LH was not decreased with the LigaSure (Medtronic, Minneapolis, MN) impedance monitoring EBVS compared with competing EBVS systems monitoring impedance or temperature (2.00 mL; 95% CI, -8.09 to 12.09; p = .70). No significant differences in hemorrhage, transfusion, or major complications were noted for all interventions.

CONCLUSION

Perioperative misoprostol in AH led to a reduction in surgical blood loss and postoperative Hb drop (moderate level of evidence by Grading of Recommendations, Assessment, Development and Evaluation guidelines) although the clinical benefit is likely limited. Remaining interventions, although promising, had at best low-quality evidence to support their use at this time. Larger and rigorously designed randomized trials are needed to establish the optimal set of perioperative interventions for use in hysterectomy for leiomyomas.

Different Role of Caveolin-1 Gene in the Progression of Gynecological Tumors

Caveolin-1 (Cav-1), an integral membrane protein, is a principal component of caveolae and has been reported to play a promoting or inhibiting role in cancer progression. Gynecologic tumor is a group of tumors that affect the tissue and organs of the female reproductive system, especially cervical cancer. Cervical cancer, as one of the most common cancers, severely affects female health in developing countries in particular because of its high morbidity and mortality. This review summarizes some mechanisms of Cav-1 in the development and progression of gynecological tumors. The role of Cav-1 in tumorigenesis, including dysregulation of cell cycle, apoptosis and autophagy, adhesion, invasion, and metastasis, such as the formation of invadopodia and matrix metalloproteinase degradation are presented in detail. In addition, Cav-1 modulates autophagy and the formation of invadopodia and target regulated by miRNAs to affect tumor progress. Taken together, we find that, no matter Cav-1 expression in the tumor or stromal cells , Cav-1 has paradoxical role in different types of gynecological tumors in vivo or in vitro and even in the same tumor from the same organ.

Circulating sex hormone binding globulin: An integrating biomarker for an adverse cardio-metabolic profile in obese pregnant women

Sex hormone-binding globulin (SHBG) negatively associates with pre-gestational body mass index (BMI) and gestational weight gain. The link with other cardio-metabolic risk factors in pregnant women is poorly understood. Our aim was to study the association of SHBG levels with common cardio-metabolic risk parameters in pregnant woman.

Serum SHBG was quantified in 291 Caucasian pregnant women (142 with normal weight, 42 with pregestational obesity, 50 with gestational obesity and 57 with pregestational plus gestational obesity) with uncomplicated pregnancies and parturition. Cardio-metabolic [C-reactive protein (CRP), blood pressure (BP), glycosylated hemoglobin (HbAc1), glucose, C-peptide, insulin, triglycerides and high molecular weight (HMW) adiponectin], and endocrine [testosterone and estradiol] parameters were also assessed.

SHBG was negatively correlated with BMI, but also with CRP, BP, HbAc1, pre and post-load glucose, C-peptide, HOMA-IR, triglycerides; and positively with HMW adiponectin (all p<0.01 to p<0.0001). These associations were more robust in women with pregestational plus gestational obesity, who had lower SHBG, in comparison to normal-weight women (p<0.0001). In multivariate analyses in women with pregestational plus gestational obesity SHBG showed independent associations with CRP (β = −0.352, p = 0.03, R² = 8.0%), DBP (β = −0.353, p = 0.03, R² = 7.0%) and SBP (β = −0.333, p = 0.04, R² = 6.0%) independently of BMI and metabolic and endocrine parameters.

SHBG is decreased in pregnant women with pregestational plus gestational obesity in association with common cardio-metabolic parameters. SHBG could represent an integrating biomarker for an adverse cardio-metabolic profile in pregnant women with pregestational plus gestational obesity.

SHBG expression is correlated with PI3K/AKT pathway activity in a cellular model of human insulin resistance

Decreased sex hormone-binding globulin (SHBG) expression is an independent risk factor for gestational diabetes mellitus(GDM).However, the mechanisms that link low SHBG expression and insulin resistance in GDM is unclear. In this study, we investigated the placenta SHBG in the PI3K/AKT pathway to reveal the mechanism that links decreased SHBG to insulin resistance. A insulin resistance cells model was established by the method of insulin stimulation. Two groups were set up, HTR8/Svneo cells and insulin-resistance cells of HTR8/SVneo. The expression of SHBG and PI3K/AKT associated factors were detected using real-time PCR and western blotting and their correlations were analyzed. The results showed that SHBG protein and mRNA levels in insulin resistance cells were both significantly lower. Along with decreased SHBG expression, the mRNA and protein levels of IRS-1, IRS-2, PI3Kp85α and GLUT-3, GLUT-4 decreased significantly. However, the expression of GLUT-1 increased significantly. Pearson correlation analysis showed that SHBG mRNA expression was positively correlated with IRS-1, IRS-2 and PI3Kp85α mRNA levels. According to the results, low SHBG expression not only participates in the development of local insulin resistance, but may also play an important role in PI3K/AKT pathway-mediated systemic insulin resistance and gestational diabetes.

Oxytocin: its role in benign prostatic hyperplasia via the ERK pathway

The aim of the present study was to evaluate oxytocin and benign prostatic hyperplasia (BPH), and study the cell signalling mechanism. Investigation was performed in patients about the correlation between oxytocin level and BPH. Mice were injected with oxytocin or oxytocin antagonist for 2 weeks and the prostate morphology was studied after their sacrifice. Furthermore, in vitro experiments were performed to evaluate the oxytocin effect through the MEK/ERK/RSK pathway. Oxytocin was significantly elevated in the serum and prostate tissue of patients with BPH, and a positive correlation with prostate volume indicated. In the animal experiments, prostate enlargement was observed in the oxytocin-treated group, whereas oxytocin antagonist reduced prostate hyperplasia. The in vitro study confirmed this result and also revealed activation of the MEK/ERK/RSK pathway. Oxytocin is highly expressed in the serum and prostate tissue of patients with BPH. In addition, oxytocin aggravates BPH and the oxytocin-induced proliferative effect on prostatic cells is mediated through the MEK/ERK/RSK pathway, at least partly. Thus, the hypothalamic regulation may be involved in development of BPH, which may open a new door to more medications for BPH in the future.

Expression of CAVEOLIN 1 in uterine mesenchymal tumors: No relationship between malignancy and CAVEOLIN 1 expression

Although most smooth muscle neoplasms detected in the human uterus are benign, uterine leiomyosarcoma (Ut-LMS) is extremely malignant with high rates of recurrence and metastasis. CAVEOLIN 1 (CAV1) levels in the epithelial cells of some carcinomas have been reported to increase during tumor progression. We herein evaluated the relationship between CAV1 expression and the pathological features of patients diagnosed with uterine mesenchymal tumors at several clinical facilities. No clinical link was observed between CAV1 expression and the malignancy of human uterine mesenchymal tumors. CAV1 expression was decreased in the normal myometrium, whereas it was strongly expressed in uterine mesenchymal tumors. However, the expression of CAV1 was not a potential biomarker to distinguish Ut-LMS from other types of uterine mesenchymal tumors. The perivascular expression of CAV1 was clearly observed in all types of uterine mesenchymal tumors and myometria. Therefore, the results of the present study suggest that CAV1 may not act as a potential biomarker of uterine malignant mesenchymal tumors.

Gene and protein expression of progesterone receptor isoforms A and B, p53 and p21 in myometrium and uterine leiomyoma

PURPOSE

To assess gene and protein expression of progesterone receptor isoforms A and B, cell cycle regulators p53 and p21 in leiomyoma and myometrium.

METHODS

Samples were collected from 14 patients in reproductive age who underwent abdominal hysterectomy. Gene expression of PRA, PRB, p53 and p21 was analyzed by real-time PCR. Protein expression was assessed by Western blots.

RESULTS

There was no change in gene and protein expression of PRA and PRB in both tissues. The ratio between isoforms (PRA:PRB) was not different between tissues and showed a strong correlation (r = 0.767, P = 0.004). The analysis of gene expression and protein showed increased levels of mRNA and protein p53 in leiomyoma compared to myometrium (P = 0.030 and P = 0.002, respectively). The same increase was observed in p21 mRNA levels (P = 0.016) and protein p21 levels (P = 0.026) in samples of uterine leiomyoma.

CONCLUSIONS

PRA:PRB ratio is similar in normal myometrium and leiomyomas. p53 and p21 mRNA and protein levels are increased in leiomyomas.

Prospective association of serum androgens and sex hormone-binding globulin with subclinical cardiovascular disease in young adult women: the "Coronary Artery Risk Development in Young Adults" women's study

CONTEXT

The role of endogenous androgens and SHBG in the development of cardiovascular disease in young adult women is unclear.

OBJECTIVE

Our objective was to study the prospective association of serum androgens and SHBG with subclinical coronary and carotid disease among young to middle-aged women.

DESIGN AND SETTING

This was an ancillary study to the Coronary Artery Risk Development in Young Adults (CARDIA) study, a population-based multicenter cohort study with 20 yr of follow-up.

PARTICIPANTS

Participants included 1629 women with measurements of serum testosterone and SHBG from yr 2, 10, or 16 and subclinical disease assessment at yr 20 (ages 37-52 yr).

MAIN OUTCOME MEASURES

Coronary artery calcified plaques (CAC) and carotid artery intima-media thickness (IMT) were assessed at yr 20. The IMT measure incorporated the common carotid arteries, bifurcations, and internal carotid arteries.

RESULTS

SHBG (mean of yr 2, 10, and 16) was inversely associated with the presence of CAC (multivariable adjusted odds ratio for women with SHBG levels above the median = 0.59; 95% confidence interval = 0.40-0.87; P = 0.008). SHBG was also inversely associated with the highest quartile of carotid-IMT (odds ratio for women with SHBG levels in the highest quartile = 0.56; 95% confidence interval = 0.37-0.84; P for linear trend across quartiles = 0.005). No associations were observed for total or free testosterone with either CAC or IMT.

CONCLUSION

SHBG levels were inversely associated with subclinical cardiovascular disease in young to middle-aged women. The extent to which low SHBG is a risk marker or has its own independent effects on atherosclerosis is yet to be determined.

Human uterine leiomyoma-derived fibroblasts stimulate uterine leiomyoma cell proliferation and collagen type I production, and activate RTKs and TGF beta receptor signaling in coculture

Background

Uterine leiomyomas (fibroids) are benign smooth muscle tumors that often contain an excessive extracellular matrix (ECM). In the present study, we investigated the interactions between human uterine leiomyoma (UtLM) cells and uterine leiomyoma-derived fibroblasts (FB), and their importance in cell growth and ECM protein production using a coculture system.

Results

We found enhanced cell proliferation, and elevated levels of ECM collagen type I and insulin-like growth factor-binding protein-3 after coculturing. There was also increased secretion of vascular endothelial growth factor, epidermal growth factor, fibroblast growth factor-2, and platelet derived growth factor A and B in the media of UtLM cells cocultured with FB. Protein arrays revealed increased phosphorylated receptor tyrosine kinases (RTKs) of the above growth factor ligands, and immunoblots showed elevated levels of the RTK downstream effector, phospho-mitogen activated protein kinase 44/42 in cocultured UtLM cells. There was also increased secretion of transforming growth factor-beta 1 and 3, and immunoprecipitated transforming growth factor-beta receptor I from cocultured UtLM cells showed elevated phosphoserine expression. The downstream effectors phospho-small mothers against decapentaplegic -2 and -3 protein (SMAD) levels were also increased in cocultured UtLM cells. However, none of the above effects were seen in normal myometrial cells cocultured with FB. The soluble factors released by tumor-derived fibroblasts and/or UtLM cells, and activation of the growth factor receptors and their pathways stimulated the proliferation of UtLM cells and enhanced the production of ECM proteins.

Conclusions

These data support the importance of interactions between fibroid tumor cells and ECM fibroblasts in vivo, and the role of growth factors, and ECM proteins in the pathogenesis of uterine fibroids.

Oxytocin-induced cell growth proliferation in human myometrial cells and leiomyomas

OBJECTIVE

To assess the expression of the oxytocin receptor (OTR) and the role of oxytocin (OT) in the proliferation of myometrial and leiomyoma cells.

DESIGN

Prospective laboratory study.

SETTING

Research laboratory at the Italian National Research Council.

PATIENT(S)

Twenty-two women who underwent therapeutic myomectomy for fibroids.

INTERVENTION(S)

Primary cultures of leiomyoma and myometrium cells were established from eutopic and ectopic myometrial tissues. An immortalized myometrial cell line (h-TERTmyo) and a leiomyosarcoma cell line (SK-UT-1) were also characterized.

MAIN OUTCOME MEASURE(S)

Expression of OTR and desmin mRNA was determined by quantitative real-time polymerase chain reaction. Cell growth was determined by 3-[4,5-dimethylthiazol-2-yl]5-(3-carboxymethoxyphenyl)2-(4-sulfophenyl)-2H tetrazolium assay. Apoptosis was determined by annexin V cell staining and flow cytometry analysis.

RESULT(S)

Oxytocin stimulated proliferation of primary myometrial and leiomyoma cells but inhibited the proliferation of h-TERTmyo and SK-UT-1, indicating a change in phenotype during immortalization. A progressive and rapid decrease in desmin and OTR mRNA was observed in primary cultures, indicating that myometrial cells dedifferentiate very rapidly in culture. The relative expression of OTR mRNA varied widely in both myometrial and leiomyoma smooth muscle cells, but there was no significant difference.

CONCLUSION(S)

These results indicate that OT stimulates the proliferation of both myometrial and leiomyoma cells, demonstrating that the OT/OTR system plays an important role in regulating uterine cell growth and providing a rationale for evaluating the use of OTR antagonists in managing uterine myomas.