Current concepts in the pathology and epigenetics of endometrial carcinoma

Epigallocatechin Gallate for the Treatment of Benign and Malignant Gynecological Diseases-Focus on Epigenetic Mechanisms

The most common malignant gynecologic diseases are cervical, uterine, ovarian, vaginal, and vulvar cancer. Among them, ovarian cancer causes more deaths than any other cancer of the female reproductive system. A great number of women suffer from endometriosis, uterine fibroids (UFs), adenomyosis, dysmenorrhea, and polycystic ovary syndrome (PCOS), which are widespread benign health problems causing troublesome and painful symptoms and significantly impairing the quality of life of affected women, and they are some of the main causes of infertility. In addition to the available surgical and pharmacological options, the effects of supporting standard treatment with naturally occurring compounds, mainly polyphenols, are being studied. Catechins are responsible for the majority of potential health benefits attributed to green tea consumption. Epigallocatechin gallate (EGCG) is considered a non-toxic, natural compound with potential anticancer properties. Antioxidant action is its most common function, but attention is also drawn to its participation in cell division inhibition, apoptosis stimulation and epigenetic regulation. In this narrative review, we describe the role of EGCG consumption in preventing the development of benign reproductive disorders such as UF, endometriosis, and PCOS, as well as malignant gynecologic conditions. We discuss possible epigenetic mechanisms that may be related to the action of EGCG.

Research Progress of DNA Methylation in Endometrial Cancer

Endometrial cancer (EC)) is one of the most common malignant tumors of the female genital system, with an increasing incidence and mortality, worldwide. Although the therapeutic strategy of EC is still complicated and challenging, further understanding of carcinogenesis from a gene perspective would allow an effort to improve therapeutic precision in this complex malignancy. DNA methylation is the most widely studied epigenetic alteration in human tumors. Aberrant DNA methylation events, resulting in altered gene expression, are features of many tumor types. In this review, we provide an update on evidence about the roles of aberrant DNA methylation within some classical tumor suppressor genes and oncogenes in endometrial carcinogenesis, and report on recent advances in the understanding of the contribution of aberrant DNA methylation to EC, as well as opportunities and challenges of DNA methylation in EC management and prevention.

Pathologic characteristics, patterns of care, and outcomes of Asian-Americans and Pacific islanders with uterine cancer

OBJECTIVES

To compare the patterns of care and outcomes of Asian-Americans/Pacific Islanders (AAPI) to non-Hispanic White (NHW) women with uterine cancer, and examine differences across Asian country of origin.

METHODS

National Cancer Database was used to identify AAPI and NHW women with uterine cancer diagnosed from 2004 to 2017. Marginal multivariable log-linear regression models and Cox proportional-hazards models were developed to estimate differences in quality-of-care and all-cause mortality between AAPI and NHW women and across AAPI ethnic groups.

RESULTS

We identified 13,454 AAPI and 354,693 NHW women. Compared to NHW women, AAPI patients were younger at diagnosis (median age 57 vs. 62 years), had fewer comorbidities, more often had serous or sarcoma histologic subtypes and stage III/IV cancer. AAPI women had a slightly higher rate of receiving pelvic lymphadenectomy for deeply invasive or high-grade tumors (77.6% vs. 74.3%), and a lower rate of undergoing minimally invasive surgery (70.4% vs. 74.8%) for stage I-IIIC tumors. Among patients undergoing hysterectomy, AAPI women had a lower mortality compared with NHW women for cancer stage I/II/III, and a 28% reduction for type I (grade 1 or 2 endometrioid cancers) disease (aHR = 0.72; 95% CI, 0.64-0.81). Among AAPI subgroups, Pacific Islanders had the worst survival across different cancer stage and disease type.

CONCLUSION

AAPI women are diagnosed with uterine cancer at a younger age and have more aggressive histologic subtypes and advanced stage than their White counterparts. They have a similar level of quality-of-care as NHW women, and an improved survival for early stage and type I disease.

Hyaluronic Acid-Functionalized Nanomicelles Enhance SAHA Efficacy in 3D Endometrial Cancer Models

Simple Summary

One of the major limitations to cancer therapies are the side effects caused by the drug interacting with any tissue in the body. There is often a balance between patient health and effectively treating the disease. To by-pass this balancing act nanoparticles are being used to deliver therapeutics straight to the tumors, acting as “Trojan Horses”. Endometrial cancers are known to have more of the cell surface protein CD44 than healthy tissues. Here, to efficiently target endometrial cancer, hyaluronic acid, which naturally binds to the CD44 protein was attached to the surface of nanoparticles and tested on microtissues or spheroids to better model a tumor and understand drug delivery performance. We show that our hyaluronic acid-nanoparticle formulations improve drug effects and interact with the cancer cells more than without this targeting agent.

Abstract

Histone Deacetylase (HDAC) enzymes are upregulated in cancer leading to the development of HDAC inhibiting compounds, several of which are currently in clinical trials. Side effects associated with toxicity and non-specific targeting indicate the need for efficient drug delivery approaches and tumor specific targeting to enhance HDAC efficacy in solid tumor cancers. SAHA encapsulation within F127 micelles functionalized with a surface hyaluronic acid moiety, was developed to target endometrial cancer cells expressing elevated levels of CD44. In vitro viability and morphology analyses was conducted in both 2D and 3D models to assess the translational potential of this approach. Encapsulation enhanced SAHA delivery and activity, demonstrating increased cytotoxic efficacy in 2D and 3D endometrial cancer models. High-content imaging showed improved nanoparticle internalization in 2D and CD44 enhanced penetration in 3D models. In addition, the nano-delivery system enhanced spheroid penetration resulting in cell growth suppression, p21 associated cell cycle arrest, as well as overcoming the formation of an EMT associated phenotype observed in free drug treated type II endometrial cancer cells. This study demonstrates that targeted nanoparticle delivery of SAHA could provide the basis for improving its efficacy in endometrial cancer. Using 3D models for endometrial cancer allows the elucidation of nanoparticle performance and CD44 targeting, likely through penetration and retention within the tumor model.

Potential Role for a Panel of Immunohistochemical Markers in the Management of Endometrial Carcinoma

BACKGROUND

In order to improve the efficacy of endometrial carcinoma (EC) treatment, identifying prognostic factors for high risk patients is a high research priority. This study aimed to assess the relationships among the expression of estrogen receptors (ER), progesterone receptors (PR), human epidermal growth factor receptor 2 (HER2), Ki-67, and the different histopathological prognostic parameters in EC and to assess the value of these in the management of EC.

METHODS

We examined 109 cases of EC. Immunohistochemistry for ER, PR, HER2, and Ki-67 were evaluated in relation to age, tumor size, International Federation of Gynecology and Obstetrics (FIGO) stage and grade, depth of infiltration, cervical and ovarian involvement, lymphovascular space invasion (LVSI), and lymph node (LN) metastasis.

RESULTS

The mean age of patients in this study was 59.8 ± 8.2 years. Low ER and PR expression scores and high Ki-67 expression showed highly significant associations with non-endometrioid histology (p = .007, p < .001, and p < .001, respectively) and poor differentiation (p = .007, p < .001, and p <. 001, respectively). Low PR score showed a significant association with advanced stage (p = .009). Low ER score was highly associated with LVSI (p = .006), and low PR scores were associated significantly with LN metastasis (p = .026). HER2 expression was significantly related to advanced stages (p = .04), increased depth of infiltration (p = .02), LVSI (p = .017), ovarian involvement (p = .038), and LN metastasis (p = .038). There was a close relationship between HER2 expression and uterine cervical involvement (p = .009). Higher Ki-67 values were associated with LN involvement (p = .012).

CONCLUSIONS

The over-expression of HER2 and Ki-67 and low expression of ER and PR indicate a more malignant EC behavior. An immunohistochemical panel for the identification of high risk tumors can contribute significantly to prognostic assessments.

A novel solution configuration on liquid-based endometrial cytology

OBJECTIVE

Early detection and diagnosis of endometrial carcinoma and precancerous change would undoubtedly become the most alluring part for researchers. With the emergence of endometrial brush samplers, a new upsurge in endometrial cytology is in the making. But endometrial specimens obtained by the endometrial brush samplers require special preservation solution. The objective of this study is to develop a new kind of endometrial-cell preservation solution and to test the availability compared with a patented liquid-based cell preservation solution.

METHODS

In this controlled study, we had 5 endometrial cases collected with Li Brush from the First Affiliated Hospital of Xi'an Jiaotong University (09/2016 to 12/2016). The samples of each case were collected 2 times separately and perserved in different perservation solutions. One was a kind of novel endometrial cell preservation solution and the other was a kind of patented liquid-based cell (LBC) preservation solution. The endometrial cells were smeared on slides by using the ZP-C automated slide preparation system and stained with Papanicolaou stain. A semi-quantitative scoring system was used to analyze the quality of slides. Statistical analysis was performed using the Wilcoxon signed rank test on the SPSS program (SPSS 18.0). In all LBC preparations, endometrial cells from the novel endometrial cells preservation solution had more cell quantity, less red blood cell fragments, and the background was cleaner compared with control group. Although the novel endometrial-cell preservation solution showed cellularity and absence of blood and debris expressed by no statistically significant differences (p = 0.063 and 0.102 respectively). The preservation period of the two kinds of liquids was equivalent.

CONCLUSIONS

The novel endometrial-cell preservation solution is superior to the liquid-base cell preservation solution for cervical cells, with clear background, diagnostic cells and low cost.

Mutant p53 induces EZH2 expression and promotes epithelial-mesenchymal transition by disrupting p68-Drosha complex assembly and attenuating miR-26a processing

The tumor suppressor p53 and the transcriptional repressor Enhancer of Zeste Homolog 2 (EZH2) have both been implicated in the regulation of epithelial-mesenchymal transition (EMT) and tumor metastasis via their impacts on microRNA expression. Here, we report that mutant p53 (mutp53) promotes EMT in endometrial carcinoma (EC) by disrupting p68-Drosha complex assembly. Overexpression of mutp53 has the opposite effect of wild-type p53 (WTp53), repressing miR-26a expression by reducing pri-miR-26a-1 processing in p53-null EC cells. Re-expression of miR-26a in mutp53 EC cells decreases cell invasion and promotes mesenchymal-epithelial transition (MET). Rescuing miR-26a expression also inhibits EZH2, N-cadherin, Vimentin, and Snail expression and induces E-cadherin expression both in vitro and in vivo. Moreover, patients with higher serum miR-26a levels have a better survival rate. These results suggest that p53 gain-of-function mutations accelerate EC tumor progression and metastasis by interfering with Drosha and p68 binding and pri-miR-26a-1 processing, resulting in reduced miR-26a expression and EZH2 overexpression.

The reduced PDCD5 protein is correlated with the degree of tumor differentiation in endometrioid endometrial carcinoma

Endometrial cancer is one of the most common malignancies in the female genital tract. Programmed cell death 5 (PDCD5) is a newly identified apoptosis related gene and plays an important role in the development of some human tumors. However, the expression and clinical significance of PDCD5 in endometrial cancer have not been fully elucidated. Here, we evaluated the expression of PDCD5 in endometrioid endometrial carcinoma and control endometrium by qRT-PCR, western blot and immunohistochemistry, and analyzed the associations of PDCD5 expression with clinicopathological parameters of patients. In addition, we detected the expression of PDCD5 in control endometrial glandular epithelial cells and endometrioid endometrial carcinoma-derived cell line KLE by immunocytochemistry. The results showed that PDCD5 protein mainly expressed in the cytoplasm of glandular epithelial cells and endometrial carcinoma cells, and there was a low level of PDCD5 expression in the nuclei of the above cells. Furthermore, PDCD5 protein level was significantly lower in endometrial carcinoma samples than that in control endometrium. The decreased PDCD5 expression was correlated with the tumor differentiation degree. It is clear that PDCD5 protein expression was lower in middle and low differentiated endometrial carcinoma compared with control endometrium and high differentiated endometrial carcinoma. However, there were no significant differences of PDCD5 expression between the proliferative phase and the secretory phase of control endometrium, as well as between high differentiated endometrial carcinoma and controls. The results were verified in control glandular epithelial cells and KLE cells by immunocytochemistry. Therefore, PDCD5 may play a key role in the pathogenesis of endometrial cancer and may be a novel target for diagnosis and treatment of endometrial cancer.

Expression and effects of JMJD2A histone demethylase in endometrial carcinoma

Previous studies have demonstrated that JMJD2A is a potential oncogene and is overexpressed in human tumors. However, its role in the endometrial carcinoma remains largely unknown. In this study, we discovered that JMJD2A was overexpressed in endometrial carcinoma, using immunohistochemistry, quantitative real- time polymerase chain reaction, and western blotting. Downregulation of JMJD2A led to reduced endometrial carcinoma RL95-2 and ISK cell proliferation, invasion and metastasis as asessed with cell counting kit-8, cell migration and invasive assays. Collectively, our results support that JMJD2A is a promoter of endometrial carcinoma cell proliferation and survival, and is a potential novel drug target.

DNA methylation as a biomarker for the detection of hidden carcinoma in endometrial atypical hyperplasia

OBJECTIVE

Women with atypical hyperplasia (AH) are often found to have endometrial carcinoma (EC) at hysterectomy. The purpose of this study was to evaluate whether the hypermethylation of specific genes found by methylomic approaches to the study of gynecologic cancers is a biomarker for EC in women with AH.

METHODS

We evaluated the methylation of AJAP1, HS3ST2, SOX1, and PTGDR from 61 AH patients undergoing hysterectomy. Endometrial biopsy samples were analyzed by bisulfite conversion and quantitative methylation-specific polymerase chain reaction. A methylation index was used to predict the presence of cancer. To confirm the silencing effects of DNA methylation, immunohistochemical analysis of AJAP1, HS3ST2, and SOX1 was performed using tissue microarray.

RESULTS

Fourteen (23%) patients had EC at hysterectomy. AJAP1, HS3ST2, and SOX1 were highly methylated in the EC patients' biopsy samples (p≤0.023). AJAP1, HS3ST2, and SOX1 protein expression was significantly higher in patients with AH only (p≤0.038). The predictive value of AJAP1, HS3ST2, and SOX1 methylation for EC was 0.81, 0.72, and 0.70, respectively. Combined testing of both AJAP1 and HS3ST2 methylation had a positive predictive value of 56%, methylation of any one of AJAP1, SOX1, or HS3ST2 had a 100% negative predictive value.

CONCLUSIONS

Hypermethylation of AJAP1, HS3ST2, and SOX1 is predictive of EC in AH patients. Testing for methylation of these genes in endometrial biopsy samples may be a hysterectomy-sparing diagnostic tool. Validation of these new genes as biomarkers for AH screening in a larger population-based study is warranted.

High expression of cyclin A is associated with poor prognosis in endometrial endometrioid adenocarcinoma

Cyclins are a group of proteins that act as activators to cyclin-dependent kinases and are required for normal cell cycle transitions. Cyclin A is involved in the transitions between G1 to S and G2 to M. Its deregulation has been linked to a number of neoplasms, including endometrial cancer. The prognostic significance of cyclin A expression seems to be cancer-specific, and current knowledge on its impact on survival of endometrial cancer is limited. This study aimed to investigate the effect of cyclin A expression on cancer-specific survival and its correlation with conventional prognostic factors in endometrioid adenocarcinoma. Biopsies obtained from 211 patients were immunohistochemically stained for cyclin A and differences in expression analyzed at the Oulu University Hospital. Patients were divided into two groups utilizing the ROC curve. Further survival analyses were carried out between these two groups. In this study, we show that cyclin A expression correlates with tumor grade and FIGO stage. We also show that cyclin A is an independent prognostic factor in endometrioid adenocarcinoma. Whether cyclin A plays a role in tumorigenesis or merely is a marker of increased proliferation requires further studies.

Hospital-based study of epithelial malignancies of endometrial cancer frequency in lahore, pakistan, and common diagnostic pitfalls

The current study was conducted to see the frequency of epithelial malignancies of endometrium with focus on the common diagnostic pitfalls and identify morphological and immunohistochemical markers helpful in the differential diagnosis between different subtypes. It is a retrospective descriptive study carried out on 52 specimens of endometrial tumors received in Fatima Memorial Hospital, Lahore, Pakistan, during three years (2010–2012). Patients were divided into 5 age groups: <40, 41–50, 51–60, 61–70, and >70 yrs. Tissues were fixed in 10% formalin and processed and stained with haematoxylin-eosin. Stained slides were examined to determine the histological types by WHO classification, and immunohistochemistry for WT1, p53, ER/PR, and MIB1 was done in cases where morphology alone was not helpful in making a confirmed diagnosis. 80% of specimens were of endometrioid adenocarcinomas, 11% of serous tumors, 4% of clear cell carcinoma, and 4% of squamous cell carcinomas involving both cervix and endometrium. Most of the patients (28.84%) with endometrial carcinomas fall in the age range of 51–60 yrs. Endometrioid adenocarcinoma is the most common type of epithelial endometrial malignancies. Morphology is the keystone in the evaluation of these tumors, but immunohistochemistry can also be helpful in establishing the correct diagnosis.

Etiologic heterogeneity in endometrial cancer: evidence from a Gynecologic Oncology Group trial

OBJECTIVE

Although the epidemiology of typical endometrial carcinomas (grades 1-2 endometrioid or Type I) is well established, less is known regarding higher grade endometrioid or non-endometrioid carcinomas (Type II). Within a large Gynecologic Oncology Group trial (GOG-210), which included central pathology review, we investigated the etiologic heterogeneity of endometrial cancers by comparing risk factors for different histologic categories.

METHODS

Based on epidemiologic questionnaire data, risk factor associations, expressed as odds ratios (OR) with 95% confidence intervals (CI), were estimated comparing grade 3 endometrioid and Type II cancers (including histologic subtypes) to grades 1-2 endometrioid cancers.

RESULTS

Compared with 2244 grades 1-2 endometrioid cancers, women with Type II cancers (321 serous, 141 carcinosarcomas, 77 clear cell, 42 mixed epithelial with serous or clear cell components) were older; more often non-white, multiparous, current smokers; and less often obese. Risk factors for grade 3 endometrioid carcinomas (n=354) were generally similar to those identified for Type II cancers, although patients with grade 3 endometrioid tumors more often had histories of breast cancer without tamoxifen exposure while those with Type II tumors were more frequently treated with tamoxifen. Patients with serous cancers and carcinosarcomas more frequently had breast cancer histories with tamoxifen treatment compared to patients with other tumors.

CONCLUSIONS

Risk factors for aggressive endometrial cancers, including grade 3 endometrioid and non-endometrioid tumors, appear to differ from lower grade endometrioid carcinomas. Our findings support etiologic differences between Type I and II endometrial cancers as well as additional heterogeneity within Type II cancers.

Overexpression of enhancer of zeste homolog 2 (EZH2) and focal adhesion kinase (FAK) in high grade endometrial carcinoma

OBJECTIVE

The deregulation of E-cadherin is associated with Src/FAK signaling axis and histone deacetylase (HDAC)/EZH2 activity. However, the association between EZH2 and FAK and its clinical significance in endometrial carcinoma has not been reported.

METHODS

202 archived cases of endometrial carcinoma (1996-2000) were reviewed and divided into two subtypes. TMAs were developed as per established procedures. EZH2, FAK, and pFAK immunohistochemical stains were performed and the expression was scored as negative (0), low (1) and high (2). Proper statistical analysis was used to assess the correlation between the expression profiles and the clinicopathological parameters and clinical outcome.

RESULTS

A total of 141 (69.8%) type-1 tumors and 61 (30.2%) type-2 tumors were identified. EZH2 overexpression was identified in 7.6% of type-1 tumors vs. 63% of type-2 tumors (p<0.001). FAK and pFAK overexpression was only seen in 24.8% and 1.7% of Type-1 tumors as compared to 72% and 58.8% of type-2 tumors, respectively (p<0.001). A positive correlation between the expression of EZH2, FAK, pFAK and PTEN (p<0.0001) was found. The overexpression of EZH2, FAK, and pFAK were significantly associated with high histologic grade, angiolymphatic invasion, lymph node metastasis, myometrial invasion and cervical involvement (p<0.01). Kaplan-Meier analysis demonstrates that the overexpression of EZH2 (p=0.0024), FAK and pFAK (p=0.0001) was significantly associated with decreased overall survival.

CONCLUSION

The overexpression of EZH2, FAK and pFAK correlates with well established pathologic risk factors and may predict a more aggressive biologic behavior in endometrial carcinoma, transforming these proteins into potential therapeutic targets for treatment of endometrial cancer.

Genetic variants in ER cofactor genes and endometrial cancer risk

Given that the transcriptional regulatory activity of estrogen receptor (ER) is modulated by its biochemical cofactors, genetic variation within the ER cofactor genes may alter cellular response to estrogen exposure and consequently modify the risk for endometrial cancer. We genotyped 685 tagging SNPs within 60 ER cofactor genes in 564 endometrial cancer cases and 1,510 controls from Sweden, and tested their associations with the risk of endometrial cancer. We investigated the associations of individual SNPs by using a trend test as well as multiple SNPs within a gene or gene complex by using multi-variant association analysis. No significant association was observed for any individual SNPs or genes, but a marginal association of the cumulative genetic variation of the NCOA2 complex as a whole (NCOA2, CARM1, CREBBP, PRMT1 and EP300) with endometrial cancer risk was observed (P_adjusted = 0.033). However, the association failed to be replicated in an independent European dataset of 1265 cases and 5190 controls (P = 0.71). The results indicate that common genetic variants within ER cofactor genes are unlikely to play a significant role in endometrial cancer risk in European population.

Racial disparities in histopathologic characteristics of uterine cancer are present in older, not younger blacks in an equal-access environment

OBJECTIVE

We sought to determine whether racial disparities in tumor characteristics among uterine cancer patients persisted, and varied by age, in an equal-access healthcare population.

METHODS

The distributions of tumor histology, stage and grade by race were compared for uterine cancers diagnosed from 1990 to 2003 using data from the U.S. Department of Defense's Automated Central Tumor Registry. Comparisons were conducted overall and stratified by age (<50, ≥50) using the Chi-square test.

RESULTS

Of 2582 uterine tumors identified, 2057 (79.7%) were diagnosed among White women and 183 (7.1%) among Black women. Among all women analyzed, Blacks were more likely than Whites to present with non-endometrioid tumors (47.7% vs 23.5%, p<0.01), non-localized tumors (31.8% vs 24.5%, p=0.02), and poorly differentiated tumors (20.5% vs 15.0%, p<0.01). Among women 50 years and older, similar significant racial disparities were observed. However, no significant racial differences were observed among young patients. When comparisons were restricted to endometrioid histology adenocarcinomas, trends in age-specific disparities for older women were observed.

CONCLUSIONS

Our study suggests that racial disparities in uterine cancers persist between Blacks and Whites in an equal-access population. Blacks endure higher stage and grade tumors, and more aggressive histologies. This disparity in clinicopathologic factors is confined to women older than 50 years. Multiple factors such as racial variation in age-related health knowledge/behavior and estrogen metabolism may be related to the racial disparity.