Transcriptional analysis of steroid hormone receptors in smooth muscle uterine leiomyoma tumors of postmenopausal patients

Differences in gynecologic tumor development in Amhr2-Cre mice with KRASG12D or KRASG12V mutations

How different KRAS variants impact tumor initiation and progression in vivo has not been thoroughly examined. We hypothesize that the ability of either KRAS^G12D or KRAS^G12V mutations to initiate tumor formation is context dependent. Amhr2-Cre mice express Cre recombinase in tissues that develop into the fallopian tubes, uterus, and ovaries. We used these mice to conditionally express either the KRAS^G12V/+or KRAS^G12D/+ mutation. Mice with the genotype Amhr2-Cre Pten^(fl/fl) Kras^G12D/+(G12D mice) had abnormal follicle structures and developed low-grade serous ovarian carcinomas with 100% penetrance within 18 weeks. In contrast, mice with the genotype Amhr2-Cre Pten^(fl/fl) Kras^G12V/+ (G12V mice) had normal follicle structures, and about 90% of them developed uterine tumors with diverse histological features resembling those of leiomyoma and leiomyosarcoma. Granulosa cell tumors also developed in G12V mice. Differences in cell-signaling pathways in the uterine tissues of G12D and G12V mice were identified using RNA sequencing and reverse-phase protein array analyses. We found that CTNNB1, IL1A, IL1B, TNF, TGFB1, APP, and IL6 had the higher activity in G12V mice than in G12D mice. These mouse models will be useful for studying the differences in signaling pathways driven by Kras^G12V/+ or Kras^G12D/+ mutations to aid development of targeted therapies for specific KRAS mutant variants. Our leiomyoma model driven by the Kras^G12V/+ mutation will also be useful in deciphering the malignant progression from leiomyoma to leiomyosarcoma.

Increased risk of breast cancer in women with uterine myoma: a nationwide, population-based, case-control study

Objective

To evaluate if uterine myoma is associated with breast cancer.

Methods

This case-control study used a nationwide database in Taiwan. We identified 24,315 patients with newly diagnosed breast cancer as cases and matched them with 24,281 patients without breast cancer on age, sex, urbanization, income, and initial diagnosis date. Patients with prior mastectomy were excluded. We used logistic regression analysis to assess the association between uterine myoma and breast cancer while adjusting for confounders. We evaluated the impact of surgical removal of uterine myoma on subsequent breast cancer among patients with uterine myoma.

Results

We found that 2,892 (11.9%) patients with newly diagnosed breast cancer and 2,541 (10.5%) patients without breast cancer had a history of uterine myoma. The association between breast cancer and uterine myoma was significant (adjusted odds ratio [aOR]=1.14; 95% confidence interval [CI]=1.07–1.21; p<0.001). This association remained in patients who used hormone (aOR=1.20; 95% CI=1.08–1.33; p=0.001) or who did not use hormone (aOR=1.11; 95% CI=1.03–1.19; p=0.005) within 5 years prior to the index date. Surgical removal of uterine myoma was not associated with a decreased risk of breast cancer (aOR=0.99; 95% CI=0.88–1.10; p=0.795).

Conclusion

A minor increased risk of breast cancer was found in women with a history of uterine myoma. This association remained in patients with recent hormone use. Removal of uterine myoma was not associated with decreased risk of breast cancer.

Reactivation of codogenic endogenous retroviral (ERV) envelope genes in human endometrial carcinoma and prestages: Emergence of new molecular targets

Endometrial carcinoma (EnCa) is the most common invasive gynaecologic carcinoma. Over 85% of EnCa are classified as endometrioid, expressing steroid hormone receptors and mostly involving pathological prestages. Human endogenous retroviruses (ERV) are chromosomally integrated genes, account for about 8% of the human genome and are implicated in the etiology of carcinomas. The majority of ERV envelope (env) coding genes are either not present or not consistently represented between common gene expression microarrays. The aim of this study was to analyse the absolute gene expression of all known 21 ERV env genes including 19 codogenic and two env genes with premature stop codons in EnCa, endometrium as well as in hyperplasia and polyps. For EnCa seven env genes had high expression with >200 mol/ng cDNA (e.g. envH1-3, Syncytin-1, envT), two middle >50 mol/ng cDNA (envFc2, erv-3) and 12 low <50 mol/ng cDNA (e.g. Syncytin-2, envV2). Regarding tumor parameters, Syncytin-1 and Syncytin-2 were significantly over-expressed in advanced stage pT2 compared to pT1b. In less differentiated EnCa Syncytin-1, erv-3, envT and envFc2 were significantly over-expressed. Syncytin-1, Syncytin-2 and erv-3 were specific to glandular epithelial cells of polyps, hyperplasia and EnCa using immunohistochemistry. An analysis of 10 patient-matched EnCa with endometrium revealed that the ERV-W 5' long terminal repeat regulating Syncytin-1 was hypomethylated, including the ERE and CRE overlapping MeCP2 sites. Functional analyses showed that 10 env genes were regulated by methylation in EnCa using the RL95-2 cell line. In conclusion, over-expressed env genes could serve as indicators for pathological pre-stages and EnCa.

Estrogen receptors and human disease: an update

A myriad of physiological processes in mammals are influenced by estrogens and the estrogen receptors (ERs), ERα and ERβ. As we reviewed previously, given the widespread role for estrogen in normal human physiology, it is not surprising that estrogen is implicated in the development or progression of a number of diseases. In this review, we are giving a 5-year update of the literature regarding the influence of estrogens on a number of human cancers (breast, ovarian, colorectal, prostate, and endometrial), endometriosis, fibroids, and cardiovascular disease. A large number of sophisticated experimental studies have provided insights into human disease, but for this review, the literature citations were limited to articles published after our previous review (Deroo and Korach in J Clin Invest 116(3):561-570, 2006) and will focus in most cases on human data and clinical trials. We will describe the influence in which estrogen's action, through one of or both of the ERs, mediates the aforementioned human disease states.

Enhanced transcription of estrogen receptor α and mitochondrial cytochrome b genes in uterine leiomyomas

The relative expression levels of estrogen receptor α (ERα) and mitochondrial cytochrome b (MTCYB) transcripts and their association with ERα, -397T > C gene polymorphism was determined in premenopausal uterine leiomyomas and myometrium tissues to gain an insight into the role of ER-mediated action of estrogen on mitochondrial gene transcription. Both ERα and MTCYB transcripts were overexpressed in leiomyomas compared with myometrium tissues with 9.18 ± 0.79 folds and 5.24 ± 0.48 folds, respectively. ERα demonstrated ≥1.7 folds overexpression expressed over MTCYB (p < 0.001). Genotype correlation with transcript expression revealed that leiomyomas with CC genotype had significantly increased levels of ERα with 11.9 ± 1.02 folds as compared with 6.46 ± 0.56 folds seen in CT and TT genotypes together (p < 0.001). Interestingly, MTCYB transcript levels were also >1.9 folds overexpressed in leiomyomas with the CC genotype as compared with leiomyomas with other genotypes (p < 0.01).Significant elevation of ERα and MTCYB transcript levels in premenopausal leiomyomas and its association with ERα, -397 CC genotype suggests the mitochondrial-mediated role of estrogen as the promoter of leiomyoma tumorigenesis.

Surgical management of uterine fibroids at aminu kano teaching hospital

Objective. To determine the influence of age and parity on the surgical management of uterine fibroids, clinical presentation, presence of pelvic adhesions, cadre of surgeons, and postoperative complications at the Aminu Kano Teaching Hospital, Kano, Nigeria. Methods. A retrospective analysis of 105 cases of uterine fibroids that were managed between 1st January 2003 and 31st December 2007. Results. The period prevalence of uterine fibroids was 24.7% of all major gynecological operations. The mean age was 35.8 ± 7.6 and mean parity 4.7 ± 2.8. Abdominal hysterectomy accounted for 58.1% of the cases and myomectomy 41.9%. The odd of using abdominal hysterectomy was about twice that of myomectomy. Pelvic adhesions were found in 67.6% of the cases. Menorrhagia (86.7%) was the commonest symptom, while post operative anemia and pyrexia showed significant association with myomectomy. There was no maternal mortality. Conclusion. Surgical operations for uterine fibroids are safe and common kind of gynecological operations at the Aminu Kano Teaching Hospital. Uterine fibroid is associated more with high parity and dominance of abdominal hysterectomy over myomectomy, because early girl marriage is common in our community.

Involvement of Bcl-2, Src, and ERα in gossypol-mediated growth inhibition and apoptosis in human uterine leiomyoma and myometrial cells

AIM

to investigate the effect of gossypol on the growth of cultured human uterine leiomyoma and myometrial cells, the level of Bcl-2 and the activity of Src and estrogen receptor (ERα).

METHODS

human uterine leiomyoma and adjacent normal myometrial cells were cultured in vitro. Both cell types were treated with a graded concentration of gossypol. Cell viability was assayed using CCK-8. Morphological change was observed with optical and electronic microscopy. Apoptosis was evaluated using TUNEL assay. Levels of Bcl-2, ERα and Src were analyzed using Western blotting.

RESULTS

gossypol significantly inhibited growth and promoted apoptosis in cultured human uterine leiomyoma cells with the IC(50) value and its corresponding 95% confidence intervals (CI) of 6.5 (4.0-10.5), 9.0 (4.9-16.5), and 7.5 (4.0-14.1) micromol/L at 20, 40, and 60 h, respectively. Gossypol exerted inhibitory effects on the myometrial cells with the IC(50) value and its 95% CI of 49.1 (28.3-85.0), 14.5 (7.7-27.4), and 2.6 (1.2-5.6) micromol/L at 20, 40, and 60 h, respectively. Compared with control, gossypol 0.1-3.0 micromol/L markedly decreased the protein expression of Bcl-2 (P<0.05) in both leiomyoma and myometrial cells in a concentration-dependent manner, and significantly suppressed the level of phospho-Tyr416Src (P<0.05) in both cell types at 3.0 micromol/L without obvious alteration of c-Src and phospho-Tyr527Src levels (P>0.05). In addition, gossypol markedly reduced both the expression of ERα (P<0.05) at the low concentration of 0.1 micromol/L in the myometrial cells and the level of phospho-ser167ERα (P<0.05) at the high concentration of 3.0 μmol/L in the leiomyoma cells.

CONCLUSION

gossypol inhibits proliferation and induces apoptosis in human uterine leiomyoma and myometrial cells. It is likely that the mechanisms of action involve reducing the protein level of Bcl-2 and the activity of Src and ERα.

Estrogen receptor beta gene polymorphisms and susceptibility to uterine fibroids

Uterine fibroids are the most common benign tumors of the female genital tract. Steroid hormones, especially estradiol and progesterone, play an important role in the pathobiology of this frequent disease. Recent studies suggested that both expression levels and polymorphisms of estrogen receptor (ER) alpha and beta might affect development of uterine fibroids. In this study, we tested whether single nucleotide polymorphisms (SNPs) in the promoter of estrogen receptor beta gene (ESR2) are associated with susceptibility to uterine fibroids. For this purpose, we compared the frequency of three SNPs in the promoter region of ESR2 gene (rs2987983, rs3020450 and rs3020449) in 101 women with uterine fibroids and 102 healthy women serving as controls by means of allele-specific tetra-primer polymerase chain reaction (PCR). Regarding allele frequency, allele positivity, genotype and haplotype frequencies of these SNPs we did not observe any significant difference between healthy women and women with uterine fibroids. In conclusion, our data clearly suggest that the tested SNPs in the promotor region of human ESR2 gene are not associated with the development of uterine fibroids.

Estrogen and progesterone receptors: from molecular structures to clinical targets

Research involving estrogen and progesterone receptors (ER and PR) have greatly contributed to our understanding of cell signaling and transcriptional regulation. In addition to the classical ER and PR nuclear actions, new signaling pathways have recently been identified due to ER and PR association with cell membranes and signal transduction proteins. Bio-informatics has unveiled how ER and PR recognize their ligands, selective modulators and co-factors, which has helped to implement them as key targets in the treatment of benign and malignant tumors. Knowledge regarding ER and PR is vast and complex; therefore, this review will focus on their isoforms, signaling pathways, co-activators and co-repressors, which lead to target gene regulation. Moreover it will highlight ER and PR involvement in benign and malignant diseases as well as pharmacological substances influencing cell signaling and provide established and new structural insights into the mechanism of activation and inhibition of these receptors.

Early aberrant insulin-like growth factor signaling in the progression to endometrial carcinoma is augmented by tamoxifen

Tamoxifen is an important selective estrogen receptor (ER) modulator for treatment of steroid hormone positive breast cancer. In addition to the beneficial effect, tamoxifen is one risk factor for endometrial carcinoma (EnCa) development. We hypothesized that, (1) dysregulation of gene expression and protein phosphorylation of the insulin-like growth factor (IGF) and steroid hormone receptor-signaling occur early in benign endometrial tissues and (2) signaling differences would be detected between patients with or without tamoxifen treatment. Seventy-eight tissues, including 2 benign cohorts from patients treated with (n = 24) or without tamoxifen (n = 28) (hyperproliferative endometrium, hyperplasia, polyps), EnCa (n = 12) with endometrium controls (n = 14) were analyzed for expression of 15 genes from the IGF and steroid hormone receptor-signaling, including the target genes Syncytin-1, PAX2 and c-myc. Total and phosphorylated protein expression were examined for ERalpha, PTEN, AKT, mTOR and Syncytin-1. Compared to controls similar significant deregulation of IGF and steroid hormone receptor-signaling, Syncytin-1 and PAX2 occurred in both benign cohorts, irrelevant of tamoxifen treatment. Comparing both benign cohorts with and without tamoxifen significant expression differences were noted. Increased total protein and phosphorylation of pERalpha-Ser118, pPTEN-Thr380, pAKT-Thr308, pAKT-Ser473, pmTOR-Ser2448 and Syncytin-1 were noted in early benign tissue stages associating with tamoxifen, especially polyps. Functional kinetic studies following tamoxifen treatment of the PTEN mutated RL95-2 EnCa cell line, demonstrated a doubling of phosphorylation of pERalpha-Ser118 and a 4.2-fold induction of pAKT-Thr308 along with Syncytin-1 induction. This study supports that dysregulated IGF and steroid hormone receptor signaling is prominent in endometrial benign stages and these alterations could represent clinical indicators for the risk of EnCa and also help in development of new therapies.

Single nucleotide polymorphisms in the progesterone receptor gene and association with uterine leiomyoma tumor characteristics and disease risk

OBJECTIVE

Uterine benign leiomyomas result from proliferation of a single smooth-muscle cell and their growth is affected by steroid hormones via steroid hormone receptors. This investigation analyzed the +331G/A and the V600L single nucleotide polymorphisms in the progesterone receptor, and correlated their incidence with clinical and tumor parameters as well as disease risk.

STUDY DESIGN

Peripheral blood DNA was analyzed for the frequency of both progesterone receptor single nucleotide polymorphisms in 270 women with uterine leiomyomas compared with 163 control women without uterine leiomyomas.

RESULTS

No correlation was found for both single nucleotide polymorphisms or the risk for developing myoma; however, statistical significant associations were found for single nucleotide polymorphism genotypes with specific clinical and tumor characteristics, eg, endometriosis, number of live births, menstrual cycle disorder, and leiomyoma focality.

CONCLUSION

Our findings support that specific genotypes in the progesterone receptor may be involved in tumor growth and metastasis but not in tumor initiation.

NIS mRNA expression level in resected thyroid tissue as a marker of postoperative hypothyroidism after subtotal thyroidectomy in patients with Graves' disease

Subtotal thyroidectomy for Graves' disease sometimes leads to hypothyroidism or relapse during long-term follow-up in a significant proportion of patients. Factors predictive of postoperative hypothyroidism after subtotal thyroidectomy are not known. The objective of this study was to determine the relation between clinical features and expression of transcripts associated with thyroid hormone synthesis in resected thyroid tissues of patients with Graves' disease. Thyroid tissues were obtained from 65 patients with Graves' disease who underwent subtotal thyroidectomy. Expression of mRNAs from thyroglobulin (Tg), TSH receptor (TSHR), thyroid peroxidase (TPO), sodium/iodide symporter (NIS), and the Pendred's syndrome (PDS) genes were analyzed by quantitative reverse transcription-polymerase chain reaction. Uni- and multivariate analyses were performed to identify for postoperative hypothyroidism. We detected significant correlations between the NIS mRNA level and levels of free T(3) (fT(3)) and free T(4) (fT(4)) and between the Tg mRNA level and goiter weight before initial drug treatment. Mean levels of expression of all five mRNAs were significantly higher in patients who did not require L-thyroxine replacement therapy than in those who required replacement therapy at 6 months after surgery. In patients who did not require replacement therapy, a significant correlation was found between NIS mRNA expression and fT(4) levels. Univariate analysis revealed that decreased NIS mRNA expression (NIS/PGK<1.69) and low TBII levels before initial treatment were significant of postoperative hypothyroidism. Multivariate analysis showed decreased expression of NIS mRNA (NIS/PGK<1.69) to be an independent risk factor for L-thyroxine replacement after surgery (risk ratio, 3.26, confidence interval, 1.36-9.08, p<0.01). NIS expression reflects the level of thyroid hormone synthesis in Graves' disease patients. Evaluation of NIS mRNA expression in thyroid tissues may help determine prognoses of Graves' disease patients, and therefore an appropriate treatment can be determined for each patient.