Genetics and the development of fibroids

Comprehensive Review of Uterine Fibroids: Developmental Origin, Pathogenesis, and Treatment

Uterine fibroids are benign monoclonal neoplasms of the myometrium, representing the most common tumors in women worldwide. To date, no long-term or noninvasive treatment option exists for hormone-dependent uterine fibroids, due to the limited knowledge about the molecular mechanisms underlying the initiation and development of uterine fibroids. This paper comprehensively summarizes the recent research advances on uterine fibroids, focusing on risk factors, development origin, pathogenetic mechanisms, and treatment options. Additionally, we describe the current treatment interventions for uterine fibroids. Finally, future perspectives on uterine fibroids studies are summarized. Deeper mechanistic insights into tumor etiology and the complexity of uterine fibroids can contribute to the progress of newer targeted therapies.

Significance of changes in inflammatory parameters following uterine artery embolization in pre-menopausal females

The purpose of the present study was to describe the course of changes in laboratory inflammatory markers following bilateral uterine artery embolization (UAE) as a treatment for leiomyomas and adenomyosis. The body temperature was measured and blood samples were collected to determine white blood cell (WBC) count and C-reactive protein (CRP) levels in 270 patients on the day prior to UAE and for up to 4 days post-embolization. Aside from a single case with a non-inflammatory complication, none of the other cases had any complications. Post-UAE leukocytosis with a mean maximum value of 10.8±3.5x10⁹/l (range, 5.9-18.6x10⁹/l) was observed one-year post-intervention. The mean leukocyte numbers were indicated to be higher on day 3 post-UAE. The CRP level was also increased post-UAE, with a mean maximum value of 7.75±3.5 mg/dl. Maximum levels were reached in 8 patients on the 2nd and in 11 patients on the 3rd post-operative day. The maximum pain score was ~5.5 and reached its lowest level at the end of the 12th week post-intervention. The present study did not consider an association between the embolic material used or uterus size with the level of treatment success. No complications were observed post-UAE; however, a significant increase in the WBC count was observed within the first 3 days, indicating mild leukocytosis.

Is ulipristal acetate the new drug of choice for the medical management of uterine fibroids? Res ipsa loquitur?

Ulipristal acetate (Esmya^©) has been hailed the new wonder drug with regard to the medical management of uterine fibroids, and many postulate that it will remove the need for surgical treatment in the future. While the results from the PEARL studies are certainly promising and its amenorrhoeic rates and reduction in fibroid size are unquestionable, there is still a paucity of data with regard to its long-term effects, the effects on its usage prior to surgery and its variable efficacy in different ethnic populations. To facilitate our knowledge further, independent studies with clear outcome measures evaluating the long-term effects of the drug in a wider, more representative, ethnic minority population as well as assessing its true cost-effectiveness compared to surgery are needed. The aim of this article is to review the historical aspects with regard to the management of uterine fibroids to gain an understanding of where we are now and to evaluate the wider use of ulipristal acetate, both its benefits and limitations and postulate where to go in the future in order to allow our women to make safe and informed choices regarding their treatment options.

Dynamic thiol/disulphide homeostasis in patients with Uterine Myoma

BACKGROUND

The aim of this study is to measure and compare the dynamic thiol and disulphide homeostasis between patients with Uterine Myoma (UM) and healthy subjects.

MATERIAL AND METHOD

A total of 54 patients with UM who were diagnosed by transvaginal ultrasonography and 37 age- and body mass index-matched healthy individuals were included in this study. Thiol/disulphide homeostasis was measured by a novel automatic spectrophotometric method.

RESULTS

The mean serum native thiol, disulphide, and thiol levels were statistically lower in UM group than those in the control group [(284.66±59.41μmol/L vs. 320.98±56.17μmol/L, P<0.0001), (17.27±5.59μmol/L vs. 22.38±6.93μmol/L, P<0.0001) and (319.21±61.69 vs. 365.76±61.46μmol/L, P<0.0001), respectively]. There were no statistically significant differences in ratios of the disulphide/native thiol, native thiol/total thiol, and disulphide/total thiol among patients with UM versus healthy control group (P=0.096, 0.092, 0.092, respectively).

CONCLUSION

It was found that the native thiol, total thiol, and disulphide levels in patients with UM decreased while the ratio of native thiol/disulphide remained unchanged.It is necessary to investigate whether these findings have a role in the etiology and clinical course of the UM.

Different dosages of mifepristone versus enantone to treat uterine fibroids: A multicenter randomized controlled trial

BACKGROUND

To evaluate the efficacy and safety of 10 mg and 25 mg mifepristone per day compared with 3.75 mg enantone in treating uterine fibroids.

METHODS

This is a Multicenter randomized controlled trial. A total of 501 subjects with symptomatic uterine fibroids were enrolled and randomized into the group of 10mg, 25mg mifepristone and 3.75 enantone (with 307, 102 and 92 subjects respectively), with 458 subjects completed the treatment. Three months of daily therapy with oral mifepristone (at a dose of either 10 mg or 25 mg) or once-monthly subcutaneous injections of enantone (at a dose of 3.75 mg) were used. Change in volume of the largest uterine fibroid was the primary efficacy variable, and secondary efficacy variables included changes in anemia and relevant symptom. Safety evaluation included the analyses of adverse events, laboratory values, and relevant endometrial changes.

RESULTS

After three months of treatment, the mean volume of the largest leiomyoma was significantly reduced by mifepristone 10 mg or 25 mg or enantone 3.75 mg (40.27%, 42.59% and 44.49% respectively) (P < 0.0001). Percentage change from baseline in largest leiomyoma volume was not statistically significant among the three groups (P = 0.1057). Most of the patients in all groups experienced amenorrhea after the treatment. There were also significant elevations in red blood cell count, hemoglobin and hematocrit (P < 0.0001), and significant reductions in prevalence of dysmenorrhea, pelvic pressure, non-menstrual abdominal pain (P < 0.0001) in each group, while no significant difference among the three groups.All study medications are well-tolerated, and no serious adverse event was reported. Treatment-related adverse event rate was significantly lower in mifepristone 10 mg group, compared to Enantone 3.75 mg group (13.59% vs. 32.58%, P = 0.0002). In both mifepristone groups, estradiol levels were maintained in the premenopausal range, whereas patients in the enantone group had a significant reduction to postmenopausal levels (P < 0.0001).

CONCLUSION

10mg is as effective as 25mg mifepristone and 3.75 mg enantone with minimal drug-related side effects, and may provide an alternative for clinical application, especially for patient who are in perimenopause with uterine fibroids.

Management of uterine fibroids in pregnancy: recent trends

PURPOSE OF REVIEW

The review analyzes how fibroids may influence pregnancy and how myomas may be modified by pregnancy. The most important clinical aspect concerns the impact of myoma on pregnancy and the possibility of a well tolerated surgical treatment for the mother and her fetus, preserving maternal reproductive capacity.

RECENT FINDINGS

Fibroids significantly increase in size during early pregnancy and then decrease in the third trimester. Although most women with uterine fibroids have a regular pregnancy, data from the literature suggest that they may have a higher risk of fertility problems and pregnancy complications.

SUMMARY

Myomectomy can increase the rate of pregnancy in women with infertility, attempting to restore a normal anatomy and reduce uterine contractility and local inflammation associated with the presence of fibroids, improving the blood supply. Current evidence does not suggest routine myomectomy during pregnancy or at the cesarean birth, as fibroids-related complications are rare and may be overcome by the risks of surgery. However, in selected cases, myomectomy is a feasible and safe technique and associated to a good outcome.The diagnosis of myomas in pregnancy may require attention for the adequate management to preserve maternal and fetal well-being.

Identification of uterine leiomyoma-specific marker genes based on DNA methylation and their clinical application

Differential diagnosis of uterine leiomyomas and leiomyosarcomas is needed to determine whether the uterus can be retained. Therefore, biomarkers for uterine leiomyomas, and reliable and objective diagnostic methods have been desired besides the pathological diagnosis. In the present study, we identified 12 genes specific to uterine leiomyomas based on DNA methylation. Using these marker genes specific to uterine leiomyomas, we established a hierarchical clustering system based on the DNA methylation level of the marker genes, which could completely differentiate between uterine leiomyomas and normal myometrium. Furthermore, our hierarchical clustering system completely discriminated uterine cancers and differentiated between uterine leiomyosarcomas and leiomyomas with more than 70% accuracy. In conclusion, this study identified DNA methylation-based marker genes specific to uterine leiomyomas, and our hierarchical clustering system using these marker genes was useful for differential diagnosis of uterine leiomyomas and leiomyosarcomas.

Randomized controlled trial of thermal balloon ablation versus vaginal hysterectomy for leiomyoma-induced heavy menstrual bleeding

OBJECTIVE

To compare the efficacy of thermal balloon ablation (TBA) with that of vaginal hysterectomy in the treatment of leiomyoma-induced heavy menstrual bleeding (HMB).

METHODS

An open-label randomized controlled trial was conducted between November 1, 2012, and October 31, 2014, in a tertiary care hospital in Delhi, India. Eligible women with HMB (aged ≥40 years, uterus size ≤14 weeks of pregnancy, leiomyoma ≤5 cm, uterocervical length ≤12 cm) were randomly assigned (1:1) to undergo TBA or vaginal hysterectomy using computer-generated random number tables. The primary outcome was the number of women in the TBA group with HMB 6 months after surgery. Analyses were by intention to treat.

RESULTS

Each group contained 20 women. No women in the TBA group had HMB at 6 months. Nineteen women were amenorrheic by 6 months and one was hypomenorrheic.

CONCLUSION

TBA can replace vaginal hysterectomy in some perimenopausal women with uterine leiomyomas. Clinical Trials Registry India: CTRI/2016/07/007119.

Overview of latest evidence on uterine fibroids

Uterine fibroids are the most common type of benign gynecologic mass, and are present in up to 80 percent of women. Research exploring risk factors for fibroids presents conflicting or inconclusive findings. Symptoms for up to 50 percent of women experiencing fibroids include heavy menstrual bleeding, pelvic pressure or pain and gastrointestinal and genitourinary changes. Diagnosis is made by history and symptoms, physical examination and imaging. Several treatment options are available, and are based on symptoms, preferences and reproductive plans. Given the high prevalence of fibroids and the potential for women's health implications, it is essential that clinicians are aware of the latest evidence regarding fibroids to provide the highest quality of care for women whose health is affected by this condition.

The Epidemiology and Genetics of Uterine Leiomyoma

Uterine leiomyomas (fibroids) are the most common benign neoplasms in premenopausal women, which confer significant morbidity during the reproductive years and represent a significant public health issue. The incidence of fibroids has been associated with African-American race, early onset of menarche, early parity, and environmental/dietary exposures. These sex steroid-responsive uterine tumors are characterized by de novo transformation of the myometrium into fibroids via excessive formation of the extracellular matrix (ECM). Cytogenic anomalies, mutations in mediator complex subunit 12 (MED 12), and aberrant DNA methylation/demethylation have been observed, but have not been reported as direct mediators of fibroid development. Recent advances in epigenetics have implied a functional role of G protein-coupled receptor 10 (GPR10) overexpression and irregular microRNA expression in the pathobiology of fibroids that require future investigation. Herein, the impact of epidemiologic and genetic factors on the incidence and development of fibroids is reviewed.

Potential mechanisms of aberrant DNA hypomethylation on the x chromosome in uterine leiomyomas

We recently found that aberrant DNA hypomethylation is more common on the X chromosome than on other chromosomes in uterine leiomyomas by genome-wide DNA methylation profiling. To investigate the mechanism of aberrant hypomethylation on the X chromosome in uterine leiomyomas, we analyzed methylome and transcriptome data from three cases of leiomyomas and the adjacent myometrium. We found that eleven of the aberrantly hypomethylated genes on the X chromosome were common to the three cases. None of these 11 genes were transcriptionally upregulated in the leiomyoma. However, one of them, TSPYL2, was hypomethylated in 68% of multiple leiomyoma specimens. The incidence of aberrant hypomethylation of TSPYL2 was comparable to that of the MED12 mutation (68%), which is known to be detected at a high frequency in uterine leiomyomas. We also analyzed the aberration of the X chromosome inactivation (XCI) mechanism in uterine leiomyomas. Hypomethylation was not enriched in the imprinted genes, suggesting that dysfunction of polycomb repressive complexes is not involved in the aberrant hypomethylation on the X chromosome. The expression analysis of XCI-related genes revealed that the XIST and SATB1 expression was downregulated in 36% and 46% of 11 leiomyoma specimens, respectively, while the HNRNPU and SMCHD1 expression was not altered. In conclusion, the aberration of XCI-related genes such as SATB1 or XIST may be involved in aberrant hypomethylation on the X chromosome in a certain population of the patients with uterine leiomyomas. TSPYL2 of the aberrantly hypomethylated genes on the X chromosome can be used as a biomarker of uterine leiomyomas.

Cervical neoplasia-related factors and decreased prevalence of uterine fibroids among a cohort of African American women

OBJECTIVE

To investigate whether the previously reported inverse association between cervical neoplasia and uterine fibroids is corroborated.

DESIGN

Cross-sectional analysis of enrollment data from an ongoing prospective study of fibroid development.

SETTING

Not applicable.

PATIENT(S)

Self-reported data on abnormal Pap smear, colposcopy, and cervical treatment were obtained from 1,008 African American women ages 23-34 with no previous fibroid diagnosis and no reported history of human papillomavirus vaccination. Presence of fibroids was assessed at a standardized ultrasound examination.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The association between the three cervical neoplasia-related variables and the presence of fibroids was evaluated with logistic regression to estimate age-adjusted and multivariable-adjusted odds ratios (aORs).

RESULT(S)

Of the analysis sample, 46%, 29%, and 14% reported a prior abnormal Pap smear, colposcopy, and cervical treatment, respectively. Twenty-five percent had fibroids at ultrasound. Those reporting cervical treatment had a 39% (aOR, 0.61; 95% confidence interval [CI] [0.38-0.96]) reduction in fibroid risk. Weak nonsignificant associations were found for abnormal Pap smear and colposcopy.

CONCLUSION(S)

Although a protective-type association of cervical neoplasia with uterine fibroids seems counterintuitive, a causal pathway is possible, and the findings are consistent with two prior studies. Further investigation is needed on the relationship between fibroids and cervical neoplasia and human papillomavirus-related mechanisms.

The role of angiogenic factors in fibroid pathogenesis: potential implications for future therapy

BACKGROUND

It is well established that tumors are dependent on angiogenesis for their growth and survival. Although uterine fibroids are known to be benign tumors with reduced vascularization, recent work demonstrates that the vasculature of fibroids is grossly and microscopically abnormal. Accumulating evidence suggests that angiogenic growth factor dysregulation may be implicated in these vascular and other features of fibroid pathophysiology.

METHODS

Literature searches were performed in PubMed and Google Scholar for articles with content related to angiogenic growth factors and myometrium/leiomyoma. The findings are hereby reviewed and discussed.

RESULTS

Multiple growth factors involved in angiogenesis are differentially expressed in leiomyoma compared with myometrium. These include epidermal growth factor (EGF), heparin-binding-EGF, vascular endothelial growth factor, basic fibroblast growth factor, platelet-derived growth factor, transforming growth factor-β and adrenomedullin. An important paradox is that although leiomyoma tissues are hypoxic, leiomyoma feature down-regulation of key molecular regulators of the hypoxia response. Furthermore, the hypoxic milieu of leiomyoma may contribute to fibroid development and growth. Notably, common treatments for fibroids such as GnRH agonists and uterine artery embolization (UAE) are shown to work at least partly via anti-angiogenic mechanisms.

CONCLUSIONS

Angiogenic growth factors play an important role in mechanisms of fibroid pathophysiology, including abnormal vasculature and fibroid growth and survival. Moreover, the fibroid's abnormal vasculature together with its aberrant hypoxic and angiogenic response may make it especially vulnerable to disruption of its vascular supply, a feature which could be exploited for treatment. Further experimental studies are required in order to gain a better understanding of the growth factors that are involved in normal and pathological myometrial angiogenesis, and to assess the potential of anti-angiogenic treatment strategies for uterine fibroids.

Uterine fibroids: pathogenesis and interactions with endometrium and endomyometrial junction

Uterine leiomyomas (fibroids or myomas) are benign tumors of uterus and clinically apparent in a large part of reproductive aged women. Clinically, they present with a variety of symptoms: excessive menstrual bleeding, dysmenorrhoea and intermenstrual bleeding, chronic pelvic pain, and pressure symptoms such as a sensation of bloatedness, increased urinary frequency, and bowel disturbance. In addition, they may compromise reproductive functions, possibly contributing to subfertility, early pregnancy loss, and later pregnancy complications. Despite the prevalence of this condition, myoma research is underfunded compared to other nonmalignant diseases. To date, several pathogenetic factors such as genetics, microRNA, steroids, growth factors, cytokines, chemokines, and extracellular matrix components have been implicated in the development and growth of leiomyoma. This paper summarizes the available literature regarding the ultimate relative knowledge on pathogenesis of uterine fibroids and their interactions with endometrium and subendometrial myometrium.

Genome-wide linkage and association analyses implicate FASN in predisposition to Uterine Leiomyomata

Uterine leiomyomata (UL), the most prevalent pelvic tumors in women of reproductive age, pose a major public health problem given their high frequency, associated morbidities, and most common indication for hysterectomies. A genetic component to UL predisposition is supported by analyses of ethnic predisposition, twin studies, and familial aggregation. A genome-wide SNP linkage panel was genotyped and analyzed in 261 white UL-affected sister-pair families from the Finding Genes for Fibroids study. Two significant linkage regions were detected in 10p11 (LOD = 4.15) and 3p21 (LOD = 3.73), and five additional linkage regions were identified with LOD scores > 2.00 in 2q37, 5p13, 11p15, 12q14, and 17q25. Genome-wide association studies were performed in two independent cohorts of white women, and a meta-analysis was conducted. One SNP (rs4247357) was identified with a p value (p = 3.05 × 10(-8)) that reached genome-wide significance (odds ratio = 1.299). The candidate SNP is under a linkage peak and in a block of linkage disequilibrium in 17q25.3, which spans fatty acid synthase (FASN), coiled-coil-domain-containing 57 (CCDC57), and solute-carrier family 16, member 3 (SLC16A3). By tissue microarray immunohistochemistry, we found elevated (3-fold) FAS levels in UL-affected tissue compared to matched myometrial tissue. FAS transcripts and/or protein levels are upregulated in various neoplasms and implicated in tumor cell survival. FASN represents the initial UL risk allele identified in white women by a genome-wide, unbiased approach and opens a path to management and potential therapeutic intervention.

Leiomyoma: genetics, assisted reproduction, pregnancy and therapeutic advances

PURPOSE

Uterine leiomyomas are common, benign, reproductive tract tumors affecting a majority of reproductive aged women. They are associated with gynecologic morbidity and detrimentally affect reproductive potential. The etiology of leiomyomas is poorly understood and their diagnosis prior to treatment with Assisted Reproductive Technologies (ART) represents a management dilemma. The purpose of this paper is to review known genetic and molecular contributions to the etiologies of leiomyomas, describe their impact on ART outcomes and reproductive potential, and review alternative therapies and future directions in management.

METHODS

A critical review of the literature pertaining to genetic component of uterine leiomyomas, their impact on ART and pregnancy and leiomyoma therapeutics was performed.

RESULTS

Uterine leiomyomas are characterized by complex molecular mechanisms. Their location and size determines their potential detriment to ART and reproductive function and novel therapeutic modalities are being developed.

CONCLUSION

The high prevalence of uterine leiomyomas and their potential detrimental influence on ART and reproductive function warrants continued well-designed studies to ascertain their etiology, optimal treatment and novel less morbid therapies.

Treatment of uterine myoma with 5 or 10mg mifepristone daily during 6 months, post-treatment evolution over 12 months: double-blind randomised clinical trial

OBJECTIVES

To evaluate the efficacy and safety of 5 and 10mg doses of mifepristone for 6 months for the treatment of uterine fibroids and to check those results at 1 year post-treatment.

STUDY DESIGN

Randomised double-blind clinical study carried out at the "Eusebio Hernández" Hospital, Havana, Cuba. One hundred and seventy-six women with symptomatic uterine fibroids received one daily capsule of 10mg mifepristone orally or one daily capsule of 5mg mifepristone orally, over 6 months. Up to two endometrial biopsies were performed. Reduction in fibroid volume was used to evaluate efficacy.

RESULTS

The 5 and 10mg dose had a similar efficacy in reducing the fibroid volume, 48.1% and 39.1%, p=0.07, and that of the uterus, 30.3% and 27.2%, p=0.63, respectively. Twelve months after treatment the majority of the subjects were asymptomatic with symptom prevalence similar to that at the end of treatment, except for hypermenorrhea and metrorrhagia, although the intensity of hypermenorrhea was much less, p<0.01.

CONCLUSIONS

(1) Both doses obtain similar results in reducing fibroid size. (2) Administering 6 months' treatment achieves symptomatic improvement lasting 1 year in a high percentage of cases. (3) More studies need to be carried out with longer treatment and follow-up periods.

Disseminated peritoneal leiomyomatosis after laparoscopic supracervical hysterectomy with characteristic molecular cytogenetic findings of uterine leiomyoma

Disseminated peritoneal leiomyomatosis (DPL) is a rare condition characterized by scattered smooth muscle nodules over the peritoneal surfaces. The pathogenesis of DPL remains unclear. Herein, we report a case of DPL occurring 7 years after laparoscopic supracervical hysterectomy with morcellation for uterine leiomyomata (UL). We analyzed both the original UL and the subsequent DPL by molecular cytogenetics to assess the role of chromosomal abnormalities in DPL pathobiology. Interestingly, all of the chromosomal aberrations detected in this case of DPL, including r(1)(p34.3q41), del(3)(q23q26.33), and t(12;14)(q14.3;q24.1), are characteristic chromosomal abnormalities detected in UL. Fluorescence in situ hybridization analysis of the initial UL confirmed an interstitial deletion spanning at least 3q24 and 3q25.1, suggesting that functional alteration of a potential gene in this chromosomal region may play a role in DPL development from UL. With the increasing rate of hysterectomy through laparoscopic approach to UL, the unique complications of laparoscopy with morcellation, especially seeding and proliferation of tumor cells over abdominal organs and peritoneum, are becoming more significant and may necessitate review of current surgical protocols to prevent future seeding of the pelvic region with tumor particles.

Low-dose mifepristone in treatment of uterine leiomyoma: a randomised double-blind placebo-controlled clinical trial

AIMS

To evaluate the effect of low-dose mifepristone on leiomyoma-related symptoms, uterine and leiomyoma in women with symptomatic leiomyomata.

METHODS

In a double-blind placebo-controlled trial, 40 patients with symptomatic leiomyoma and normal endometrial histology were randomised to receive 10 mg mifepristone (group 1) or placebo (group 2) daily for three months. Leiomyoma-related symptoms, uterine, leiomyoma and largest leiomyoma volumes were assessed at baseline and every month for three months. Endometrial biopsy was repeated at the end of therapy.

RESULTS

Significant change was noticed between the two groups for mean menstrual blood loss (MBL) by first month. Menstrual blood loss declined by 94.8% in group 1 at three months and 84.2% patients attained amenorrhoea in this group. In group 1 complete relief of dysmenorrhoea occurred in significant number of women (80%) but only 33% patients got rid of pelvic pain. There was no change in these symptoms in group 1 Backache, urinary complaints and dyspareunia were not relieved in either group. Uterine, leiomyoma and largest leiomyoma volume declined by 26-32% in group 1 as compared to none in group 2, and this difference was statistically significant only by the end of the third month of therapy. Mean haemoglobin increased from 9.5 to 11.2 g/dL in group 1. In group 1, at the end of therapy, 63.1% of patients had endometrial hyperplasia without atypia.

CONCLUSIONS

Ten milligrams mifepristone for three months is effective in reducing MBL, increasing haemoglobin and reducing uterine and leiomyoma volume with side-effect of endometrial hyperplasia.

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.

Incidence, aetiology and epidemiology of uterine fibroids

Uterine fibroids are the most common benign tumour of the female genital tract. However, their true prevalence is probably under-estimated, as the incidence at histology is more than double the clinical incidence. Recent longitudinal studies have estimated that the lifetime risk of fibroids in a woman over the age of 45 years is more than 60%, with incidence higher in blacks than in whites. The cause of fibroids remains unclear and their biology poorly understood. No single candidate gene has been detected for commonly occurring uterine fibroids. However, the occurrence of rare uterine fibroid syndromes, such as multiple cutaneous and uterine leiomyomatosis, has been traced to the gene that codes for the mitochondrial enzyme, fumarate hydratase. Cytogenetic abnormalities, particularly deletions of chromosome 7, which are found in up to 50% of fibroid specimens, seem to be secondary rather than primary events, and investigations into the role of tumour suppressor genes have yielded conflicting results. The key regulators of fibroid growth are ovarian steroids, both oestrogen and progestogen, growth factors and angiogenesis, and the process of apoptosis. Black race, heredity, nulliparity, obesity, polycystic ovary syndrome, diabetes and hypertension are associated with increased risk of fibroids, and there is emerging evidence that familial predisposition to fibroids is associated with a distinct pattern of clinical and molecular features compared with fibroids in families without this prevalence.

The impact of race as a risk factor for symptom severity and age at diagnosis of uterine leiomyomata among affected sisters

OBJECTIVE

The objective of the study was to identify risk factors for uterine leiomyomata (UL) in a racially diverse population of women with a family history of UL, and to evaluate their contribution to disease severity and age at diagnosis.

STUDY DESIGN

We collected and analyzed epidemiologic data from 285 sister pairs diagnosed with UL. Risk factors for UL-related outcomes were compared among black (n = 73) and white (n = 212) sister pairs using univariate and multivariate regression models.

RESULTS

Black women reported an average age at diagnosis of 5.3 years younger (SE, 1.1; P < .001) and were more likely to report severe disease (odds ratio, 5.22; 95% confidence interval, 1.99-13.7, P < .001) than white women of similar socioeconomic status.

CONCLUSION

Self-reported race is a significant factor in the severity of UL among women with a family history of UL. Differences in disease presentation between races likely reflect underlying genetic heterogeneity. The affected sister-pair study design can address both epidemiological and genetic hypotheses about UL.

The genetic heterogeneity of uterine leiomyomata

Research investigating the genetics of UL has already been successful in gathering epidemiologic evidence for heritability, establishing the clonal and mosaic nature of these tumors, correlating genotypic and phenotypic characteristics, defining cytogenetic subgroups, and identifying specific genes involved in tumorigenesis. Although UL are known to be benign tumors, the impact they have on the lives of so many women can only be described as "malignant". For this reason, continuing the quest to ascertain the genes, functions, and mechanisms integral to UL development is absolutely imperative. Genetic tests for personalized medical management of women with fibroids is at the threshold for providing the most appropriate treatments (Fig. 3), and combined with developing less invasive therapies portends a brighter future for a major health problem for women.

Association of two polymorphisms in the peroxisome proliferator-activated receptor-gamma gene with adenomyosis, endometriosis, and leiomyomata in Japanese women

OBJECTIVE

The peroxisome proliferator-activated receptor-gamma (PPAR-gamma) is a nuclear hormone receptor that plays an important role in many diseases. This study investigated whether two polymorphisms (Pro12Ala in exon B and C161T in exon 6) of the PPAR-gamma2 gene are related to adenomyosis, endometriosis, or leiomyomata.

METHODS

A total of 390 patients with adenomyosis, endometriosis, and/or leiomyomata were classified into four groups: 103 patients with adenomyosis (21 adenomyosis only and 82 adenomyosis with endometriosis and/or leiomyomata), 95 patients with endometriosis only, 100 patients with leiomyomata only, and 92 patients with endometriosis and leiomyomata.

RESULTS

There was no association between distribution of genotype or allele frequencies for the PPAR-gamma Pro12Ala polymorphism and the presence of adenomyosis, endometriosis, and/or leiomyomata. However, compared with results for controls, the PPAR-gamma 161CC genotype and 161C allele frequencies were significantly increased in patients with adenomyosis (genotype: chi2 = 8.185, corrected P value [Pc] = .0169; allele: chi2 = 8.337, Pc = .0155) and in patients with endometriosis (genotype: chi2 = 6.748, Pc = .0375; allele: chi2 = 6.413, Pc = .0453).

CONCLUSION

The results suggest that the PPAR-gamma 161CC genotype could be a genetic risk factor for adenomyosis and endometriosis, whereas the Pro12Ala polymorphism was not associated with these estrogen-dependent benign uterine diseases in a Japanese population.

A prospective study of hypertension and risk of uterine leiomyomata

Although uterine leiomyomata (also known as fibroids or myomas) affect the reproductive health and well-being of approximately 25% of premenopausal women, risk factors are poorly understood. Elevated diastolic blood pressure may increase fibroid risk through uterine smooth muscle injury, not unlike atherosclerosis. The authors prospectively examined the relation between diastolic blood pressure and incidence of clinically detected leiomyomata. The sample included 104,233 premenopausal nurses from 14 US states enrolled in the Nurses' Health Study II. Participants, aged 25-42 years, had intact uteri and no history of cancer or fibroids at enrollment in 1989. During the 827,348 woman-years of follow-up (1989-1999), 7,466 incident diagnoses of uterine leiomyomata, confirmed by ultrasound or hysterectomy, were reported. With a multivariable Cox proportional hazards model, the relative risk of self-reported ultrasound- or hysterectomy-confirmed uterine leiomyomata according to diastolic blood pressure in 1989 and time-varying antihypertensive use was estimated. With adjustment for age, race/ethnicity, body mass index, and reproductive history covariates, for every 10-mmHg increase in diastolic blood pressure, the risk of fibroids rose 8% (5-11%) and 10% (7-13%) among nonusers and users of antihypertensive medications, respectively. Elevated blood pressure has an independent, positive association with risk for clinically detected uterine leiomyomata among premenopausal women. Investigating this association may suggest possible pathways to prevent fibroids.

Gene expression studies provide clues to the pathogenesis of uterine leiomyoma: new evidence and a systematic review

BACKGROUND

Uterine leiomyomas are extremely common and a major cause of pelvic pain, bleeding, infertility, and the leading indication for hysterectomy. Familial and epidemiological studies provide compelling evidence that genetic alterations play an important role in leiomyoma development.

METHODS

Using Affymetrix U133A GeneChip we analysed expression profiles of 22,283 genes in paired samples of leiomyoma and adjacent normal myometrium. We compared our results with previously published data on gene expression in uterine leiomyoma and identified the overlapping gene alterations.

RESULTS

We detected 80 genes with average differences of > or = 2-fold and false discovery rates of < 5% (14 overexpressed and 66 underexpressed). A comparative analysis including eight previous gene expression studies revealed eight prominent genes (ADH1, ATF3, CRABP2, CYR61, DPT, GRIA2, IGF2, MEST) identified by at least five different studies, eleven genes (ALDH1, CD24, CTGF, DCX, DUSP1, FOS, GAGEC1, IGFBP6, PTGDS, PTGER3, TYMS) reported by four studies, twelve genes (ABCA, ANXA1, APM2, CCL21, CDKN1A, CRMP1, EMP1, ESR1, FY, MAP3K5, TGFBR2, TIMP3) identified by three studies, and 40 genes reported by two different studies.

CONCLUSIONS

Review of gene expression data revealed concordant changes in genes regulating retinoid synthesis, IGF metabolism, TGF-beta signaling and extracellular matrix formation. Gene expression studies provide clues to the relevant pathways of leiomyoma development.

Involvement of fumarate hydratase in nonsyndromic uterine leiomyomas: genetic linkage analysis and FISH studies

Recently, germline mutations of the fumarate hydratase (FH) gene, in 1q42.1, have been found to be involved in syndromes associated with uterine leiomyomas (ULs). Compelling evidence also supports a genetic liability to develop nonsyndromic UL, although susceptibility genes have not been reported to date. Loss of heterozygosity (LOH) studies have found no or rare evidence of LOH of FH in nonsyndromic UL. However, the karyotypes of these tumors were not reported, and cytogenetic aberrations of 1q42-44 have been observed infrequently in UL. To determine whether FH mutations also may predispose women to developing nonsyndromic UL, we performed a genetic linkage study with DNA from 123 families containing at least one affected sister pair. In addition, to assess the frequency of FH loss specifically in UL with 1q rearrangements, we performed a fluorescence in situ hybridization (FISH) analysis of UL with 1q rearrangements. Analysis of the genotyping data revealed evidence suggestive of linkage to the FH region among study participants who were less than 40 years of age at diagnosis (Zlr 1.7 at D1S547, P = 0.04). FISH results showed that one copy of FH was absent in 9 of 11 ULs. These data indicate that loss of FH might be a significant event in the pathogenesis of a subset of nonsyndromic ULs.

Decreased expression of early growth response-1 and its role in uterine leiomyoma growth

Expression of early growth response (Egr)-1, a transcriptional factor implicated in growth regulation, is suppressed in several malignant tumors. The present study investigated the expression of Egr-1 and related genes in uterine leiomyoma and normal myometrium to determine possible contributions of Egr-1 to neoplastic growth in leiomyoma cells. Levels of Egr-1 transcripts were decreased in all leiomyomas (n = 20) to approximately 10% of levels in corresponding myometrium, where basal expression was high. Preoperative leuprorelin acetate therapy increased levels of Egr-1 mRNA in normal myometrium only. Northern blot analysis using additional sample sets (n = 5) revealed the full-length Egr-1 transcript. Western blot analysis (n = 5) confirmed decreased expression of Egr-1 protein. Southern blot analysis of the Egr-1 gene and microsatellite analysis of the chromosomal location at 5q31 (D5S414, D5S500, and D5S476) revealed neither DNA recombination nor loss of heterozygosity in leiomyomas. Moreover, Egr-1 retained identical responsiveness to phorbol 12-myristate 13-acetate in primary cultures derived from both leiomyoma and normal tissues. Electrophoretic mobility shift analysis revealed that phorbol 12-myristate 13-acetate-induced Egr-1 in leiomyoma cells retained DNA binding ability. Egr-1 thus appears functionally intact in leiomyoma cells. Finally, consistent with the role of Egr-1 in growth inhibition, transfection of Egr-1 expression vector into a myometrial cell line (KW) that expresses low levels of Egr-1 and displays rapid growth inhibited thymidine uptake in these cells. Egr-1 may display tumor-suppressing activity and offers a potential target for leiomyoma management.

HMGA2 expression in uterine leiomyomata and myometrium: quantitative analysis and tissue culture studies

The high mobility group gene, HMGA2, is frequently expressed in uterine leiomyomata (UL) with chromosomal rearrangements of 12q15. In contrast, HMGA2 expression has not been detected in karyotypically normal UL or in myometrium, but has been detected in these tissues after culture. To characterize further the expression pattern of HMGA2, we assessed HMGA2 expression by RT-PCR followed by Southern blot hybridization, and by real-time PCR in three tissue panels: (1) primary myometrial cultures, (2) uncultured tissue from 15 karyotypically normal samples consisting of eleven 46,XX UL and four matched myometrial specimens, and (3) uncultured tissue from ten UL with 12q15 rearrangements and three matched myometrial specimens. HMGA2 expression was detected in all samples from the three panels. The level of HMGA2 expression in karyotypically normal UL was similar to the level of expression in myometrium; however, it was significantly less than the level measured in UL with 12q15 rearrangements. This expression analysis by use of detection methods of different sensitivities underscores the importance of studies of HMGA2 expression in uncultured tissues and of careful interpretation of results from experiments on cultured cells. Moreover, detection of HMGA2 expression in myometrium and in UL without 12q15 rearrangements, tissues previously thought not to express HMGA2, suggests that HMGA2 expression is required in normal adult myometrial physiology.

Etiology and pathogenesis of uterine leiomyomas: a review

Uterine leiomyomas, or fibroids, represent a major public health problem. It is believed that these tumors develop in the majority of American women and become symptomatic in one-third of these women. They are the most frequent indication for hysterectomy in the United States. Although the initiator or initiators of fibroids are unknown, several predisposing factors have been identified, including age (late reproductive years), African-American ethnicity, nulliparity, and obesity. Nonrandom cytogenetic abnormalities have been found in about 40% of tumors examined. Estrogen and progesterone are recognized as promoters of tumor growth, and the potential role of environmental estrogens has only recently been explored. Growth factors with mitogenic activity, such as transforming growth factor- (subscript)3(/subscript), basic fibroblast growth factor, epidermal growth factor, and insulin-like growth factor-I, are elevated in fibroids and may be the effectors of estrogen and progesterone promotion. These data offer clues to the etiology and pathogenesis of this common condition, which we have analyzed and summarized in this review.

Heparin inhibits the motility and proliferation of human myometrial and leiomyoma smooth muscle cells

Uterine fibroids (leiomyomas) are a major women's health problem. Currently, the standard for treatment remains hysterectomy, because no other treatment modalities can reduce both symptoms and recurrence. As leiomyomas are a hyperproliferation of smooth muscle cells, we sought to understand the regulation of uterine smooth muscle cell mitogenesis by the glycosaminoglycan heparin, which has been extensively studied as an anti-proliferative molecule in vascular smooth muscle cells. Using matched pairs of human myometrial and leiomyoma smooth muscle cells from the same uterus, we demonstrate that the proliferation and motility of both cell types are inhibited by heparin. We report that the decrease in cell number seen in the presence of heparin is not because of cell death. Interestingly, there is significant patient-to-patient variability in the proliferation response but not in the motility response to heparin. Furthermore, nonanticoagulant and anticoagulant heparin were equally effective at inhibiting leiomyoma and myometrial smooth muscle cell proliferation. These results warrant further investigation into the possibility that heparin might be useful in the treatment of uterine fibroids.

Insights from gene arrays on the development and growth regulation of uterine leiomyomata

OBJECTIVE

To use microarray analysis as an unbiased approach to identify genes involved in the induction and growth of uterine leiomyomata.

DESIGN

Screen by arrays for up to 12,000 genes in leiomyoma (L) and control myometrium (M) from nine patients.

SETTING

University research laboratories.

PATIENT(S)

Nine patients in the follicular and luteal phases of the menstrual cycle.

INTERVENTION(S)

mRNA from L and M was converted to biotin-labeled cRNA and hybridized to cDNA oligonucleotide sequences on the arrays.

MAIN OUTCOME MEASURE(S)

Greater than two-fold change in gene expression between leiomyoma and matched myometrium.

RESULT(S)

Prominent among the 67 genes overexpressed in L relative to M were dlk or Pref-1, doublecortin, JM27, ionotropic glutamate receptor subunit 2, apolipoprotein E3, IGF2, semaphorin F, myelin proteolipid protein, MEST, frizzled, CRABP II, stromelysin-3, and TGFbeta3. The genes dlk, IGF2, and MEST are paternally expressed imprinted genes, and the others are involved in tissue differentiation and growth. Prominent among the 78 genes down-regulated in L relative to M were alcohol dehydrogenases 1alpha-gamma, tryptase, dermatopontin, thrombospondin, coxsackievirus receptor, nur77, and c-kit.

CONCLUSION(S)

Arrays offer large-scale screening of mRNA expression, which will help us differentiate between the genes and metabolic pathways necessary for leiomyoma growth and those regulating myometrial contractions.