Estrogen receptor-beta affects the prognosis of human malignant mesothelioma

Survival prediction in peritoneal mesothelioma: a nomogram based on SEER data and a Chinese cohort

Objective

This study aimed to develop nomogram predicting overall survival (OS) of patients with peritoneal mesothelioma (PeM) using data from Surveillance, Epidemiology, and End Results (SEER) database and a Chinese institution.

Methods

1,177 PeM patients from the SEER database were randomized into training and internal validation cohorts at a 7:3 ratio. An external validation cohort consisting of 109 patients was enrolled from a Chinese institution. Nomogram was constructed based on variables identified through multivariate Cox regression analysis and evaluated by consistency indices (C-index), calibration plots, and receiver operating characteristic (ROC) curves. Patients were stratified into different risk categories, and Kaplan-Meier survival analysis was used to assess OS differences among these groups.

Results

The nomogram, incorporating age, gender, histological type, T stage, M stage, and surgical status, demonstrated strong predictive capability with C-index values of 0.669 for the training cohort, 0.668 for the internal validation cohort, and 0.646 for the external validation cohort. The nomogram effectively stratified patients into high-risk and low-risk groups, with the high-risk group exhibiting significantly poorer OS (P < 0.05). Multivariate analysis confirmed gender, age, surgical intervention, and M stage as independent prognostic factors (P < 0.05). Specifically, male gender, older age, and unspecified M stage were linked to worse outcomes, while surgical intervention was associated with improved survival.

Conclusion

The nomogram provide a reliable tool for predicting the survival in PeM patients, facilitating more informed treatment decisions. Key independent prognostic factors include gender, age, surgical intervention, and M stage.

Genes Co-Expressed with ESR2 Influence Clinical Outcomes in Cancer Patients: TCGA Data Analysis

ERβ has been assigned a tumor suppressor role in many cancer types. However, as conflicting findings emerge, ERβ's tissue-specific expression and functional role have remained elusive. There remains a notable gap in compact and comprehensive analyses of ESR2 mRNA expression levels across diverse tumor types coupled with an exploration of its potential gene network. In this study, we aim to address these gaps by presenting a comprehensive analysis of ESR2 transcriptomic data. We distinguished cancer types with significant changes in ESR2 expression levels compared to corresponding healthy tissue and concluded that ESR2 influences patient survival. Gene Set Enrichment Analysis (GSEA) distinguished molecular pathways affected by ESR2, including oxidative phosphorylation and epithelial-mesenchymal transition. Finally, we investigated genes displaying similar expression patterns as ESR2 in tumor tissues, identifying potential co-expressed genes that may exert a synergistic effect on clinical outcomes, with significant results, including the expression of ACIN1, SYNE2, TNFRSF13C, and MDM4. Collectively, our results highlight the significant influence of ESR2 mRNA expression on the transcriptomic landscape and the overall metabolism of cancerous cells across various tumor types.

Predicting survival for patients with mesothelioma: development of the PLACE prognostic model

INTRODUCTION

The overall survival of patients with mesothelioma is poor and heterogeneous. At present, the prediction model for Chinese patients needs to be improved. We sought to investigate predictors of survival in malignant pleural mesothelioma and develop prognostic prediction models.

METHODS

This Two-center retrospective cohort study recruited patients with pathologically diagnosed mesothelioma at Beijing Chao-Yang Hospital and Beijing Tong-Ren Hospital. We developed a new prognostic prediction model based on COX multivariable analysis using data from patients who were recruited from June 1, 2010 to July 1, 2021 in Beijing Chao-Yang Hospital (n = 95, development cohort) and validated this model using data from patients recruited from July 18, 2014 to May 9, 2022 in Beijing Tong-Ren Hospital (n = 23, validation cohort). Receiver operating characteristic analysis was used to estimate model accuracy.

RESULTS

The parameters in this new model included PLT > 289.5(10^9/L) (1 point), Lymphocyte > 1.785(10^9/L) (-1point), Age > 73 years old (1 point), Calcium > 2.145(mmol/L) (-1point), Eastern Cooperative Oncology Group performance status (ECOG PS) > 2 (2 points). When the sum of scores < 0, it is recognized as a low-risk group; when the score is 0 ~ 3, it is recognized as a high-risk group. The survival rate of patients in the high-risk group was significantly lower than that in the low-risk group (hazard ratio [HR], 3.878; 95% confidence interval [CI], 2.226-6.755; P < 0.001). The validation group had similar results (HR,3.574; 95%CI,1.064-12.001; P = 0.039). Furthermore, the areas under the curve 6 months after diagnosis in the two cohorts were 0.900 (95% CI: 0.839-0.962) and 0.761 (95% CI: 0.568-0.954) for development and validation cohorts, respectively.

CONCLUSION

We developed a simple, clinically relevant prognostic prediction model for PLACE by evaluating five variables routinely tested at the time of diagnosis. The predictive model can differentiate patients of Chinese ethnicity into different risk groups and further guide prognosis.

Survival analysis and development of a prognostic nomogram for patients with malignant mesothelioma in different anatomic sites

Background

Malignant mesothelioma (MMe) is a rare and fatal cancer with a poor prognosis. Our study aimed to compare the overall survival (OS) of MMe patients across various sites and develop a prognostic model to provide a foundation for individualized management of MMe patients.

Methods

From the Surveillance, Epidemiology, and End Results (SEER) database, 1,772 individuals with malignant mesothelioma (MMe) were identified. The X-tile software was used to identify the optimal cut-off point for continuous variables. The Kaplan–Meier method was employed to compare the survival of MMe across different sites. The Cox proportional hazards model was applied to identify the independent risk factors of overall survival (OS) and a nomogram was constructed.

Results

In the survival analysis, MMe originating from the reproductive organs and hollow organs showed a relatively better prognosis than those originating from soft tissue, solid organs, and pleura. Age, gender, location, histological type, grade of differentiation, extent of disease, lymph node status, lymph node ratio (LNR), and chemotherapy were all found to be independent risk variables for the prognosis of MMe patients (P&lt;0.05) in a multivariate Cox analysis and were included in the construction of nomogram. In the training and testing sets, the C-index of the nomogram was 0.701 and 0.665, respectively, and the area under the ROC curve (AUROC) of the 1-, 3-, and 5-year overall survival rate was 0.749, 0.797, 0.833 and 0.730, 0.800, 0.832, respectively. The calibration curve shows that the nomogram is well-calibrated.

Conclusions

This is the first research to examine the prognosis of MMe patients based on the location. However, previous studies often focused on malignant pleural mesothelioma or malignant peritoneal mesothelioma with high incidence. Furthermore, a nomograph with good prediction efficiency was established according to the variables that influence patient survival outcomes, which provides us with a reference for clinical decision-making.

Survival of Korean Patients with Malignant Pleural Mesothelioma Compensated for the Asbestos Injury Relief

Background: The purpose of this study was to identify the epidemiologic characteristics and prognostic factors for malignant pleural mesothelioma in Korea, which are currently insufficient. The data were derived from malignant mesothelioma patients who registered under the Asbestos Injury Relief Act; Methods: A total of 728 patients received compensation from the Asbestos Injury Relief Act due to malignant mesothelioma between 2011 and 2015. Of these, 313 patients (43.0%) with malignant pleural mesothelioma were included in the study. The study variables were sex (male, female), age at diagnosis (<59, 60–69, ≥70), smoking history (yes, no), surgery (yes, no), chemotherapy (yes, no), occupational exposure to asbestos (yes, no), and histological subtype (epithelioid, nonepithelioid); Results: Median survival of mesothelioma was 8.0 months (95% confidence interval: 6.2 to 9.8). The 1-year, 2-year, and 5-year survival rates (%) were 43.5%, 23.6%, and 12.5%, respectively. In multivariate analysis of Cox’s proportional hazards model; sex, age, smoking history, occupational asbestos exposure, and histological subtype were not significant prognostic factors, but surgery and chemotherapy combined was a significant predictor; Conclusions: Although the representativeness of these data is limited, our study estimates the epidemiologic characteristics of malignant pleural mesothelioma. Non-occupational exposure had a similar prognosis to occupational asbestos exposure, and there was no sex difference. In addition, it was found that receiving a combination of surgery and chemotherapy affects the survival rate, but there is a limitation in that factors such as performance status, comorbidities, and stage that contribute to survival are not considered.

A narrative review of the health disparities associated with malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a cancer of the mesothelial lining of the pleura that has traditionally been associated with asbestos exposure in an industrial setting. Asbestos usage has fortunately been banned or phased out in most industrialized countries resulting in its decline in countries such as the United States. Despite this, MPM continues to place significant burden on its affected patients resulting in overall poor prognosis and survival. Questions arise as to what factors, especially what health disparities, contribute to the disease’s dismal prognosis. This article will present a narrative review of recent literature that identifies the impact age, sex, race, access to medical centers, and economics have on the diagnosis, treatment, and prognosis of MPM. As will be discussed, research has shown that factors including younger age, female sex, non-white race, private insurance, Medicare, and higher income have been associated with better survival in MPM. Whereas older age, male sex, white race, lack of insurance, and lower income are associated with worse survival. The identification of these and other health disparities related to MPM may allow for future research, clinical guidelines, and policies to be implemented to decrease the burden health disparities create in the diagnosis, treatment, and prognosis of patients with MPM.

Expression and clinical implications of estrogen receptors in thoracic malignancies: a narrative review

Thoracic malignancies represent a significant global health burden with incidence and mortality increasing year by year. Thoracic cancer prognosis and treatment options depend on several factors, including the type and size of the tumor, its location, and the overall health status of patients. Gender represents an important prognostic variable in thoracic malignancies. One of the greatest biological differences between women and men is the presence of female sex hormones, and an increasing number of studies suggest that estrogens may play either a causative or a protective role in thoracic malignancies. Over the past 60 years since the discovery of the first nuclear estrogen receptor (ER) isoform α and the almost 20 years since the discovery of the second estrogen receptor, ERβ, different mechanisms governing estrogen action have been identified and characterized. This literature review reports the published data regarding the expression and function of ERs in different thoracic malignancies and discuss sex disparity in clinical outcomes. From this analysis emerges that further efforts are warranted to better elucidate the role of sex hormones in thoracic malignancies, and to reduce disparities in care between genders. Understanding the mechanisms by which gender-related differences can affect and interfere with the onset and evolution of thoracic malignancies and impact on response to therapies could help to improve the knowledge needed to develop increasingly personalized and targeted treatments.

Preoperative Identification of Benefit from Surgery for Malignant Pleural Mesothelioma

In the absence of standardized treatment algorithms for patients with malignant pleural mesothelioma, one of the main difficulties remains patient allocation to therapies with potential benefit. This article discusses clinical, radiologic, pathologic, and molecular prognostic factors as well as genetic background leading to preoperative identification of benefit from surgery, which have been investigated over the past years to simplify and at the same time specify patient selection for surgical treatment.

Association of RERG Expression with Female Survival Advantage in Malignant Pleural Mesothelioma

Sex differences in incidence, prognosis, and treatment response have been described for many cancers. In malignant pleural mesothelioma (MPM), a lethal disease associated with asbestos exposure, men outnumber women 4 to 1, but women consistently live longer than men following surgery-based therapy. This study investigated whether tumor expression of genes associated with estrogen signaling could potentially explain observed survival differences. Two microarray datasets of MPM tumors were analyzed to discover estrogen-related genes associated with survival. A validation cohort of MPM tumors was selected to balance the numbers of men and women and control for competing prognostic influences. The RAS like estrogen regulated growth inhibitor (RERG) gene was identified as the most differentially-expressed estrogen-related gene in these tumors and predicted prognosis in discovery datasets. In the sex-matched validation cohort, low RERG expression was significantly associated with increased risk of death among women. No association between RERG expression and survival was found among men, and no relationship between estrogen receptor protein or gene expression and survival was found for either sex. Additional investigations are needed to elucidate the molecular mechanisms underlying this association and its sex specificity.

Gender Differences in Outcomes of Patients With Mesothelioma

BACKGROUND

Mesothelioma is a rare and deadly form of cancer, linked to asbestos exposure. Although the United Kingdom has banned asbestos, the incidence rate remains high. Previous research has indicated that female individuals have better survival than male individuals, but this has never been examined in the United Kingdom.

MATERIALS AND METHODS

Pleural mesothelioma cases from 2005 to 2014 were extracted from the United Kingdom Lung Cancer Dataset. Multivariable logistic regression was used to assess the clinical and demographic factors associated with gender. A multivariable Cox proportional hazards model and propensity matching methods were used to assess gender differences in overall survival while accounting for potential confounders.

RESULTS

There were 8479 (87.8%) male and 1765 (17.2%) female individuals included in the analysis. Female individuals were significantly younger, with more epithelial histology than male individuals. Female individuals had significantly better overall survival (adjusted hazard ratio, 0.85, 95% confidence interval, 0.81-0.90). Results remained similar when stratifying by age and performance status, and when limiting to patients with epithelial histology.

CONCLUSIONS

The study increases knowledge about gender differences in mesothelioma survival and is the first to directly examine this in the United Kingdom. It further disentangles the effects of age, histology, and health status. Increased estrogen may improve survival and could provide a potential target for future therapies.

Pulmonary Lymphangioleiomyomatosis originates in the pleural mesothelial cell population

Lymphangioleiomyomatosis (LAM) is a cystic lung disease mainly affecting women, in which degradation of the lung parenchyma is associated with a cell of unknown provenance, known as a LAM cell. LAM cells carry TSC2 mutations and can be identified in the lung parenchyma by their expression of both smooth muscle actin and antigens characteristic of melanocytes and melanocytic tumors. The nature of the cell-of-origin of LAM is controversial, and despite continued research effort remains elusive. Further, it has not been possible to culture pulmonary LAM cells in vitro, and current research relies on cells and animal models which may not recapitulate all features of the disease. We noted aberrant expression of melanoma antigens in pleural mesothelial cells in lung tissue from LAM patients, indicating that these cells could be the precursors of parenchymal LAM cells. We hypothesise that loss of tuberin function following TSC2 mutation in the mesothelial cell lineage gives rise to the cell-of-origin of pulmonary LAM (P-LAM), and of other associated conditions commonly noted in LAM patients. The unique properties of mesothelial cells provide a straightforward explanation of the diverse presentation of LAM.

Gender-based Disparities in Receipt of Care and Survival in Malignant Pleural Mesothelioma

BACKGROUND

Despite accounting for a minority of malignant pleural mesothelioma (MPM) diagnoses, females may experience differential survival relative to males. It is unclear if there are gender-based differences in receipt of treatment or disease-related outcomes for patients with MPM. We therefore utilized the National Cancer Database (NCDB) to assess patterns-of-care and overall survival (OS) among patients with MPM by gender.

MATERIALS AND METHODS

Patients with histologically confirmed MPM treated from 2004 to 2013 were identified from the NCDB. The association between female gender and OS was assessed using multivariable Cox proportional hazards models with propensity score matching. Patterns-of-care were assessed using multivariable logistic regression. The overall treatment effect was tested in subsets of patients by treatment strategy, histology, and clinical stage.

RESULTS

A total of 18,799 patients were identified, of whom 14,728 (78%) were male and 4071 (22%) were female. Females were statistically more likely to present at a younger age, with fewer comorbidities, and with epithelioid histology. Despite these favorable prognostic features, women were less likely to receive surgery (P ≤ .001) or chemotherapy (P ≤ .001) compared with males. On multivariable analysis, female gender was associated with improved OS (hazard ratio, 0.83; 95% confidence interval, 0.80-0.86; P ≤ .001). Gender-based survival differences were seen across all stages, but only among patients with epithelioid (P ≤ .001) and not biphasic (P = .17) or sarcomatoid (P = 1.00) histology.

CONCLUSIONS

Surgery and chemotherapy are disproportionately underutilized in female patients with MPM. Despite this concerning disparity, female gender is independently associated with improved survival relative to males. Further research to understand factors that lead to gender disparities in MPM is warranted.

Prognostic factors of survival in patients with malignant pleural mesothelioma: an analysis of the National Cancer Database

Malignant pleural mesothelioma (MPM) is a rare disease with a very poor prognosis. Previous studies have indicated that women experience longer survival compared with men. We analyzed 16 267 eligible patients (21.3% females) in the National Cancer Database to evaluate which clinical factors are independently predictive of longer survival. After adjusting for all covariates, survival was significantly better in females compared with males [HRadj: 0.81, 95% confidence interval (CI): 0.77-0.85]. Other factors significantly associated with better survival were younger age at diagnosis, higher income, lower comorbidity score, epithelial histology, earlier stage and receipt of surgical or medical treatment. After propensity matching, survival was significantly better for females compared with males [hazard ratio (HR): 0.86, 95% CI: 0.80-0.94]. After propensity matching within the epithelial group, survival remained significantly better for females compared with males (HR: 0.85, 95% CI: 0.74-0.97). This study adds information to the known significant gender survival difference in MPM by disentangling the effect of gender from the effect of age and histology, two known independent factors affecting survival. Circulating estrogen, present in young but not older women, and higher expression of the estrogen receptor beta in epithelial mesothelioma have been suggested to play a role in gender survival differences. These findings may lead to exploring new therapeutic options, such as targeting estrogen receptor beta, and considering hormonal therapy including estrogens for patients with otherwise limited prognosis.

Epidemiology of mesothelioma in the 21st century in Europe and the United States, 40 years after restricted/banned asbestos use

Research has established a strong association between asbestos exposure and malignant mesothelioma, a deadly form of cancer. Since the early 1980’s many countries have restricted or banned the production of asbestos, leading to a decline of occupational asbestos exposure in many industrialized countries. However, some countries continue to use asbestos, and worldwide rates of mesothelioma are still increasing. Because of the long latency between exposure and mesothelioma occurrence and the persistence of environmental exposure, incidence rates (IR) may decrease very slowly for several years ahead. In this review, we examine estimates of asbestos consumption before widespread asbestos regulations and the trends in incidence and mortality rates, as well as changes over time for the United States and Europe. In some countries with earlier asbestos restrictions, mesothelioma incidence has been in a modest decline over time. However, asbestos exposure is still a burden worldwide and legislative action is needed to obtain a full ban. The pattern of mesothelioma is shifting from a mostly male disease to a disease that affects females as well in substantial numbers. Studies on unknown sources of asbestos exposure, of other sources of natural exposure to asbestos and asbestos-like fibers, as well as of individual genetic susceptibility to asbestos fibers are needed.

Malignant Peritoneal Mesothelioma: Patterns of Care and Survival in the Netherlands: A Population-Based Study

BACKGROUND

Malignant peritoneal mesothelioma (MPM) is a rare and aggressive disease. Recently, focus has shifted toward a more aggressive and multimodal treatment approach. This study aimed to assess the patterns of care and survival for MPM patients in the Netherlands on a nationwide basis.

METHODS

The records of patients with a diagnosis of MPM from 1993 to 2016 were retrieved from the Dutch Cancer Registry. Data regarding diagnosis, staging, treatment, and survival were extracted. Cox regression analyses and Kaplan-Meier survival curves were used to study overall survival.

RESULTS

Between 1993 and 2016, MPM was diagnosed for 566 patients. Overall, the prognosis was very poor (24% 1-year survival). The most common morphologic subtype was the epithelioid subtype (88%), followed by the biphasic (8%) and sarcomatoid (4%) subtypes. Surgical treatment has become more common in recent years, which most likely has resulted in improved survival rates. In this study, improved survival was independently associated with hyperthermic intraperitoneal chemotherapy (hazard ratio [HR], 0.33; 95% confidence interval [CI], 0.21-0.55) and surgery with adjuvant systemic chemotherapy (HR, 0.33; 95% CI, 0.23-0.48). Nonetheless, most patients (67%) do not receive any form of anti-cancer treatment.

CONCLUSION

This study indicated that MPM still is a rare and fatal disease. The survival rates in the Netherlands have improved slightly in the past decade, most likely due to more aggressive treatment approaches and increased use of surgery. However, most patients still do not receive cancer-directed treatment. To improve MPM management, and ultimately survival, care should be centralized in expert medical centers.

Expression of estrogen receptor beta (ERβ) and its prognostic value in pleural mesothelioma

Background

Overexpression of estrogen receptors in malignant pleural mesothelioma has shown an independent relation with a better prognosis of survival, and the use of selective estrogen receptor beta (ERβ) agonists increases the susceptibility to antitumor treatment.

Methods

This was a retrospective single center study that analyzed the response of malignant pleural mesothelioma with an expression of ERβ to first-line chemotherapy. The study included patients with pleural mesothelioma pathologically confirmed between 2013 and 2016 at the National Institute for Respiratory Disease (INER), who underwent an immunohistochemistry assay for ERβ (mouse monoclonal antibody PPG5/10). The primary endpoint was the response to chemotherapy based on RECIST 1.1 according to the ERβ expression; secondary outcomes were the overall survival (OS) and progression-free survival (PFS).

Results

We included 22 patients, regarding the expression of ERβ, 17 (77.2%) patients had high or moderate degree, while 5 (22.7%) had low degree or null expression. The response to treatment as by RECIST 1.1, 12 (54.5%) had partial response, 5 (22.7%) had stable disease, and 3 (13.6%) had progression. None of the patients had a complete response. Of those who had a partial response, 9 (75%) had a high or moderate degree of ERβ expression in tumor cells, and 3 (25%) had a low or null degree of expression.

Conclusions

High and moderate expression of ERβ group with advanced clinical stage malignant pleural mesothelioma was associated with a tendency of higher OS and better response to chemotherapy treatment resulting in longer PFS although statistical significance was not achieved.

Regulation of sex hormone receptors in sexual dimorphism of human cancers

Gender differences in the incidences of cancers have been found in almost all human cancers. However, the mechanisms that underlie gender disparities in most human cancer types have been under-investigated. Here, we provide a comprehensive overview of potential mechanisms underlying sexual dimorphism of each cancer regarding sex hormone signaling. Fully addressing the mechanisms of sexual dimorphism in human cancers will greatly benefit current development of precision medicine. Our discussions of potential mechanisms underlying sexual dimorphism in each cancer will be instructive for future cancer research on gender disparities.

Is There a Role for Cancer-Directed Surgery in Early-Stage Sarcomatoid or Biphasic Mesothelioma?

BACKGROUND

Benefits of surgical resection for early-stage nonepithelioid malignant pleural mesothelioma (MPM) have not been clearly elucidated. This study investigated whether cancer-directed surgery affects overall survival compared with nonsurgical therapies for T1-T2 N0 M0 sarcomatoid or biphasic MPM patients.

METHODS

Adult patients with clinical stage I or II MPM were identified in the National Cancer Database from 2004 to 2103. Patients who underwent cancer-directed surgery were matched by propensity score with patients who had received chemotherapy/radiotherapy or no treatments. Overall survival was compared using a Cox proportional hazard regression model.

RESULTS

From National Cancer Database queries, 878 patients with clinical stage I or II MPM with sarcomatoid (n = 524) or biphasic (n = 354) histology were identified. Overall median survival was 5.5 months for patients with sarcomatoid mesothelioma. The cancer-directed surgery improved overall survival compared with no operation (median survival, 7.56 months vs 4.21 months, respectively; p < 0.01). In the biphasic group, median overall survival was 12.2 months. Again, the cancer-directed surgery improved survival compared with no operation (15.8 months vs 9.3 months, p < 0.01). For both histologies, the cancer-directed surgery improved overall survival compared with those who underwent chemotherapy or radiotherapy, or both, without resection (p < 0.05). Perioperative mortality was 6.0% at 30 days and 21.4% at 90 days.

CONCLUSIONS

The cancer-directed surgery is associated with improved survival in early-stage MPM patients with nonepithelioid histology compared with those who did not undergo resection or chose medical therapy. Given the high perioperative mortality, a careful patient selection and multidisciplinary evaluation is recommended.

Reduction of estradiol in human malignant pleural mesothelioma tissues may prevent tumour growth, as implied by in in-vivo and in-vitro models

This study aimed to investigate intratumoural estradiol and estrogen-receptors (ERα, ERβ and GPR30) in malignant pleural mesothelioma (MPM) to understand their function. Here, we report that immunohistochemistry of estradiol showed cytoplasmatic staining in 95% of fifty-seven human MPM samples with a trend toward a negative correlation between estradiol levels and the median post-diagnosis survival time. ERβ was only focally positive in 5.3% of cases, GPR30 and ERα were negative in our cases of MPM. GPR30 was detected mainly in glycosylated form in MPM cells. Moreover, G15, a GPR30 antagonist, induced MPM cell death. Altogether, these data suggest that MPM cells produce E₂ interact with glycosylated forms of GPR30, and this facilitates tumour growth. Estradiol was found in MPM cells and plasma from mice mesothelioma xenografts. Concurrent reduction in tumour mass and plasmatic estradiol levels were observed in the mice treated with exemestane, suggesting that the reduction of E₂ levels inhibit MPM growth. Thus, it appears that agents reducing estradiol levels could be useful to MPM therapy.

Stimulatory actions of IGF-I are mediated by IGF-IR cross-talk with GPER and DDR1 in mesothelioma and lung cancer cells

Insulin-like growth factor-I (IGF-I)/IGF-I receptor (IGF-IR) system has been largely involved in the pathogenesis and development of various tumors. We have previously demonstrated that IGF-IR cooperates with the G-protein estrogen receptor (GPER) and the collagen receptor discoidin domain 1 (DDR1) that are implicated in cancer progression. Here, we provide novel evidence regarding the molecular mechanisms through which IGF-I/IGF-IR signaling triggers a functional cross-talk with GPER and DDR1 in both mesothelioma and lung cancer cells. In particular, we show that IGF-I activates the transduction network mediated by IGF-IR leading to the up-regulation of GPER and its main target genes CTGF and EGR1 as well as the induction of DDR1 target genes like MATN-2, FBN-1, NOTCH 1 and HES-1. Of note, certain DDR1-mediated effects upon IGF-I stimulation required both IGF-IR and GPER as determined knocking-down the expression of these receptors. The aforementioned findings were nicely recapitulated in important biological outcomes like IGF-I promoted chemotaxis and migration of both mesothelioma and lung cancer cells. Overall, our data suggest that IGF-I/IGF-IR system triggers stimulatory actions through both GPER and DDR1 in aggressive tumors as mesothelioma and lung tumors. Hence, this novel signaling pathway may represent a further target in setting innovative anticancer strategies.

SIRT1 at the crossroads of AKT1 and ERβ in malignant pleural mesothelioma cells

In this report, we show that malignant pleural mesothelioma (MPM) patients whose tumors express high levels of AKT1 exhibit a significantly worse prognosis, whereas no significant correlation with AKT3 expression is observed. We provide data that establish a phosphorylation independent role of AKT1 in affecting MPM cell shape and anchorage independent cell growth in vitro and highlight the AKT1 isoform-specific nature of these effects.

We describe that AKT1 activity is inhibited by the loss of SIRT1-mediated deacetylation and identify, by mass spectrometry, 11 unique proteins that interact with acetylated AKT1.

Our data demonstrate a role of the AKT1/SIRT1/FOXM1 axis in the expression of the tumor suppressor ERβ. We further demonstrate an inhibitory feedback loop by ERβ, activated by the selective agonist KB9520, on this axis both in vitro and in vivo.

Our data broaden the current knowledge of ERβ and AKT isoform-specific functions that could be valuable in the design of novel and effective therapeutic strategies for MPM.

Immunohistochemistry in Peritoneal Mesothelioma: A Single-Center Experience of 244 Cases

Context.—

Diagnosis of malignant mesothelioma is more common in the chest than it is in the abdomen. Most published immunohistochemistry data are more applicable to pleural than to peritoneal mesothelioma.

Objective.—

To clarify the practical utility of 17 immunohistochemistry markers in the differential diagnosis of peritoneal mesothelioma with an emphasis on stains for which there is either contradictory information or a paucity of literature.

Design.—

Consultation files of peritoneal mesothelioma diagnoses rendered from 1999 to 2014 were reviewed; 244 cases were identified. The results of immunohistochemistry markers performed were tabulated.

Results.—

Immunohistochemistry markers positive in peritoneal mesothelioma in order of sensitivity were calretinin (244 of 244; 100%), WT1 (205 of 218; 94%), CK5/6 (173 of 194; 89%), mesothelin (132 of 150; 88%), and D2-40 (78 of 97; 80%). Markers used to differentiate carcinoma from mesothelioma showed immunoreactivity in peritoneal mesothelioma: estrogen receptor (2 of 84; 2%), B72.3 (6 of 196; 3%), CK20 (5 of 116; 4%), CD15 (7 of 192; 4%), p63 (3 of 62; 5%), carcinoembryonic antigen (9 of 199; 5%), PAX8 (12 of 191; 6%), progesterone receptor (5 of 71; 7%), Ber-EP4 (17 of 209; 8%), and CD138 (9 of 91; 10%). BAP1 loss, increasingly used in the differential diagnosis of benign versus malignant mesothelial proliferation, occured in 55% (99 of 181) of peritoneal mesothelioma cases.

Conclusions.—

The results support the experience that there is no definitive marker to rule out malignant mesothelioma, including PAX8, estrogen receptor, progesterone receptor, and p63 immunoreactivity. The high rate of immunoreactivity for mesothelin may have a role as a predictive marker for immune targeting. BAP1 loss of 55% in this cohort of peritoneal mesothelioma confirms published observations, and BAP1 retention is seen in a significant proportion of neoplastic cases.

Transcriptomic Analysis of the Claudin Interactome in Malignant Pleural Mesothelioma: Evaluation of the Effect of Disease Phenotype, Asbestos Exposure, and CDKN2A Deletion Status

Malignant pleural mesothelioma (MPM) is a highly aggressive tumor primarily associated with asbestos exposure. Early detection of MPM is restricted by the long latency period until clinical presentation, the ineffectiveness of imaging techniques in early stage detection and the lack of non-invasive biomarkers with high sensitivity and specificity. In this study we used transcriptome data mining in order to determine which CLAUDIN (CLDN) genes are differentially expressed in MPM as compared to controls. Using the same approach we identified the interactome of the differentially expressed CLDN genes and assessed their expression profile. Subsequently, we evaluated the effect of tumor histology, asbestos exposure, CDKN2A deletion status, and gender on the gene expression level of the claudin interactome. We found that 5 out of 15 studied CLDNs (4, 5, 8, 10, 15) and 4 out of 27 available interactors (S100B, SHBG, CDH5, CXCL8) were differentially expressed in MPM specimens vs. healthy tissues. The genes encoding the CLDN-15 and S100B proteins present differences in their expression profile between the three histological subtypes of MPM. Moreover, CLDN-15 is significantly under-expressed in the cohort of patients with previous history of asbestos exposure. CLDN-15 was also found significantly underexpressed in patients lacking the CDKN2A gene. These results warrant the detailed in vitro investigation of the role of CDLN-15 in the pathobiology of MPM.

Hypomethylation reduced the aggressive potential of human malignant mesothelioma cells

Epigenetic modifications have been implicated in the development of therapeutic resistance responsible for the poor prognosis of human malignant mesothelioma (HMM). To find a potential way to overcome this therapeutic resistance, this study investigated the anticancer effects of a DNA demethylating agent, 5-Aza-2'-Deoxycytidine (5-aza-dC), on HMM cells. The 5-aza-dC exhibited minimal detrimental effects on cell survival. However, treatment with 5-aza-dC significantly altered the biological characteristics associated with malignancy, such as cell migration and cell interaction, colony-forming capacity, and invasiveness. Moreover, it significantly reduced the fraction of side population (SP) cells, which are reportedly enriched for more aggressive cells. Large-scale methylation analysis based on methylated DNA immunoprecipitation revealed a more than two fold increase in the methylation level of major tumor suppressor genes in the SP fraction. The data indicated that SP cells might acquire malignancy by hypermethylation of tumor suppressor genes. Treatment with 5-aza-dC could attack more malignant cells through the modification of their methylation status. The results indicate that the modulation of DNA methylation might be a valuable strategy to overcome the therapeutic resistance of HMM. Moreover, ensuing changes in the biological characteristics provide a basis for further analysis of the role of methylation in HMM carcinogenesis.

KDM6B histone demethylase is an epigenetic regulator of estrogen receptor β expression in human pleural mesothelioma

AIM

To assess the correlation between KDM6B and estrogen receptor β (ERβ) expression in malignant pleural mesothelioma (MPM).

MATERIALS & METHODS

We evaluated gene expression by in silico analysis of microarray data, real-time PCR and western blot in MPM tumors and cell lines.

RESULTS & CONCLUSION

We report a strong positive correlation between the expression of KDM6B and ERβ in MPM tumors and cell lines. We describe that, in hypoxia, the HIF2α-KDM6B axis induces an epithelioid morphology and ERβ expression in biphasic MPM cells with estrogen receptor-negative phenotype. Reduced histone H3K27 tri-methylation confirms KDM6B activity under hypoxic conditions. Importantly, cells treated during reoxygenation with the selective ERβ agonist, KB9520, maintain ERβ expression and the less aggressive phenotype acquired in hypoxia.

Intracellular lactate-mediated induction of estrogen receptor beta (ERβ) in biphasic malignant pleural mesothelioma cells

Biphasic malignant pleural mesothelioma (MPM) is the second most common histotype of MPM. It is histologically characterized by the concomitant presence of epithelioid and sarcomatoid features, the latter associated with worse prognosis.

In this report we describe that silencing of AKT1 in spindle-shaped biphasic MPM cells promotes the shift toward an epithelioid phenotype. Furthermore, AKT1 silencing resulted in decreased expression of the lactate/H+ symporter MCT4 and its chaperone CD147/Basigin, and in the induction of estrogen receptor β (ERβ) expression. We provide evidence that ERβ expression is induced by increased intracellular lactate concentration. Spheroid culturing and tumor growth of ERβ negative biphasic MPM in nude mice resulted in the induction of ERβ expression and response to the selective agonist KB9520. In both models, the treatment with the ERβ agonist results in reduced cell proliferation, decreased expression of MCT4 and CD147/Basigin and increased acetylation and inactivation of AKT1. Collectively, in response to metabolic changes, ERβ expression is induced and exerts an anti-tumor effect through selective agonist activation. The possibility to reverse the more aggressive biphasic mesothelioma histotype by targeting ERβ with a selective agonist could represent a new effective treatment strategy.

Sexual dimorphism in cancer

The incidence of many types of cancer arising in organs with non-reproductive functions is significantly higher in male populations than in female populations, with associated differences in survival. Occupational and/or behavioural factors are well-known underlying determinants. However, cellular and molecular differences between the two sexes are also likely to be important. In this Opinion article, we focus on the complex interplay that sex hormones and sex chromosomes can have in intrinsic control of cancer-initiating cell populations, the tumour microenvironment and systemic determinants of cancer development, such as the immune system and metabolism. A better appreciation of these differences between the two sexes could be of substantial value for cancer prevention as well as treatment.

Mesothelioma from asbestos exposures: Epidemiologic patterns and impact in the United States

Mesothelioma, a rare tumor, is highly correlated with asbestos exposure. Mesothelioma, similar to all asbestos-related diseases, is dose/intensity dependent to some degree, and studies showed the risk of mesothelioma rises with cumulative exposures. Multiple processes occur in an individual before mesothelioma occurs. The impact of mesothelioma in the United States has been continuous over the last half century, claiming between 2,000 and 3,000 lives each year. Mesothelioma is a preventable tumor that is more frequently reported as associated with asbestos exposure among men than women. However, the rate of asbestos-associated mesothelioma is on the rise among women due to better investigation into their histories of asbestos exposure. It is of interest that investigators detected asbestos-associated cases of mesothelioma in women from nonoccupational sources-that is, bystander, incidental, or take-home exposures. It is postulated that asbestos-associated mesotheliomas, in both men and women, are likely underreported. However, with the implementation of the most recent ICD-10 coding system, the correlation of mesothelioma with asbestos exposure is expected to rise to approximately 80% in the United States. This study examined the demographic and etiological nature of asbestos-related mesothelioma.

Estrogen receptor β in Alzheimer's disease: From mechanisms to therapeutics

Alzheimer's disease (AD) disproportionally affects women and men. The female susceptibility for AD has been largely associated with the loss of ovarian sex hormones during menopause. This review examines the current understanding of the role of estrogen receptor β (ERβ) in the regulation of neurological health and its implication in the development and intervention of AD. Since its discovery in 1996, research conducted over the last 15-20 years has documented a great deal of evidence indicating that ERβ plays a pivotal role in a broad spectrum of brain activities from development to aging. ERβ genetic polymorphisms have been associated with cognitive impairment and increased risk for AD predominantly in women. The role of ERβ in the intervention of AD has been demonstrated by the alteration of AD pathology in response to treatment with ERβ-selective modulators in transgenic models that display pronounced plaque and tangle histopathological presentations as well as learning and memory deficits. Future studies that explore the potential interactions between ERβ signaling and the genetic isoforms of human apolipoprotein E (APOE) in brain aging and development of AD-risk phenotype are critically needed. The current trend of lost-in-translation in AD drug development that has primarily been based on early-onset familial AD (FAD) models underscores the urgent need for novel models that recapitulate the etiology of late-onset sporadic AD (SAD), the most common form of AD representing more than 95% of the current human AD population. Combining the use of FAD-related models that generally have excellent face validity with SAD-related models that hold more reliable construct validity would together increase the predictive validity of preclinical findings for successful translation into humans.

Prognostic significance of Ki67 expression in malignant peritoneal mesothelioma

OBJECTIVES

Although Ki67 measurement by immunohistochemistry has been widely used as a prognostic index in cancers, it has not been reported in malignant peritoneal mesothelioma (MPM). Hence, this study examines the prognostic significance of Ki67 in MPM.

METHODS

Specimens from 42 MPM patients were screened for Ki67 expression using immunohistochemistry. Ki67 expression was classified into 2 groups on the basis of expression (<25%=low; ≥25%=high) using standard methods. Using Kaplan-Meier survival analysis, the significance of Ki67 was assessed in different clinicopathologic categories.

RESULTS

High expression of Ki67 (≥25% by immunohistochemical evaluation) was correlated with poor survival in the overall group (P=0.001); male sex (P=0.001); female sex (P=0.001); epithelioid tumors (P=0.001): male epithelioid (P=0.001), female epithelioid (P=0.003); peritoneal cancer index (PCI): PCI<20 (P=0.001), PCI≥20 (P=0.002); and age at diagnosis (AAD): AAD<60 years (P=0.001), AAD≥60 years (P=0.004). Independent of Ki67, male sex (P=0.007), sarcomatoid histology (P=0.001), PCI≥20 (P=0.013), and AAD≥60 years (P=0.004) correlated with poor survival. Multivariate analysis showed that only AAD≥60 years (P=0.049) and high Ki67 expression for all tumors (P=0.031), male sex (P=0.038), female sex (P=0.021), epithelioid tumors (P=0.044), and AAD<60 years (P=0.029) were statistically significant.

CONCLUSIONS

Ki67 expression affects prognosis in MPM patients and helps to predict survival within the various clinicopathologic categories.

Treating peritoneal mesothelioma with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. A case series and review of the literature

BACKGROUND

Encouraging results on survival of patients with malignant peritoneal mesothelioma have been shown with the use of cytoreductive surgery and perioperative intraperitoneal chemotherapy. This study explores the impact of aggressive surgical treatment on overall survival of peritoneal mesothelioma.

METHODS

This is a retrospective analysis of prospectively collected clinical data of all patients with diagnosis of malignant peritoneal mesothelioma treated in a designated referral centre in Greece. All patients were offered cytoreductive surgery and intraperitoneal chemotherapy. Patient's characteristics, operative reports, pathology reports, and discharge summaries were stored in an electronic database and later reviewed and analysed.

RESULTS

Cytoreduction for peritoneal mesothelioma was performed on 20 patients (15 men and 5 women) with a mean age of 59.4 years (SD 16.1). Mean peritoneal cancer index was 16.1 (SD 10.4) and the median completeness of cytoreduction score was 2 (range 1-2). Mean overall survival was 46.8 months (SE 4.03) with a mean of 21.4 and median of 18 months of follow-up. Disease-specific survival was 100% for the observed period. Univariate analysis showed the completeness of cytoreduction as the only possible predictor of survival. A median of 10 (range 4-14) peritonectomy procedures were performed per patient. Median hospital stay was 14 (range 10-57 days). Grade III and IV complications occurred post-operatively in 5 patients (25%). Two patients died in the post-operative period of pulmonary embolism and myocardial infarction.

CONCLUSION

Cytoreductive surgery with HIPEC has proved the most effective treatment even when taking account of the cost of significant morbidity.

Age-dependent association between sex and renal cell carcinoma mortality: a population-based analysis

Research on sex differences in renal cancer-specific mortality (RCSM), which considered the sex effect to be constant throughout life, has yielded conflicting results. This study hypothesized the sex effect may be modified by age, which is a proxy for hormonal status. Data from the Surveillance, Epidemiology and End Results database (1988-2010) were used to identify 114,539 patients with renal cell carcinoma (RCC). The study cohort was divided into three age groups using cutoffs of 42 and 58 years, which represent the premenopausal and postmenopausal periods. The cumulative incidence function and competing risks analyses were used to examine the effect of covariates on RCSM and other-cause mortality (OCM). In premenopausal period, male sex was a significant predictor of poor RCSM for both localized (adjusted subdistribution hazard ratio [aSHR] = 1.63, P = 0.002) and advanced (aSHR = 1.20, P = 0.041) disease. In postmenopausal period, the sex disparity diminished (aSHR = 1.05, P = 0.16) and reversed (aSHR = 0.95, P = 0.017) in localized and advanced disease, respectively. On the contrary, similar trend was not found for OCM across all age groups. Our results demonstrated the sex effect on RCSM was strongly modified by age. These findings may aid in clinical practice and need further evaluation of underlying biological mechanisms.

Wnt7A is a putative prognostic and chemosensitivity marker in human malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a highly aggressive tumor that has a poor prognosis, limited treatment options, and a worldwide incidence that is expected to increase in the next decade. We evaluated Wnt7A expression in 50 surgically resected tumor specimens using quantitative PCR. The expression values, were assessed by clinicopathological factors and K-M and Cox's regression with OS. The mean level of Wnt7A expression had a significant correlation with International Mesothelioma Interest Group (IMIG) stage (P<0.034), gender, smoking history and ethnicity, respectively (P=0.020, P=0.014, P=0.039). In the univariate analysis, low Wnt7A expression was a significant negative factor for overall survival (P=0.043, HR=2.30). However, multivariate Cox's regression revealed no significant factors for overall survival (low Wnt7A: P=0.051, HR=2.283; non-epithelioid subtype: P=0.050, HR=2.898). In patients with epithelioid tumors, those with low Wnt7A expression had significantly worse prognosis (P=0.019, HR=2.98). In patients with epithelioid tumors, females had significantly better prognosis than males (P=0.035). In patients who did not have neoadjuvant chemotherapy, prognosis was significantly more favorable for patients with high Wnt7A expression than for those with low Wnt7A expression (P=0.031). Among the patients with low Wnt7A-expressing tumors, those who received neoadjuvant chemotherapy had better prognosis than those who did not (P=0.024). The results of our study suggest that Wnt7A expression is a putative prognostic factor and a predictor of chemosensitivity.

Evaluation of clonal origin of malignant mesothelioma

Background

The hypothesis that most cancers are of monoclonal origin is often accepted as a fact in the scientific community. This dogma arose decades ago, primarily from the study of hematopoietic malignancies and sarcomas, which originate as monoclonal tumors. The possible clonal origin of malignant mesothelioma (MM) has not been investigated. Asbestos inhalation induces a chronic inflammatory response at sites of fiber deposition that may lead to malignant transformation after 30-50 years latency. As many mesothelial cells are simultaneously exposed to asbestos fibers and to asbestos-induced inflammation, it may be possible that more than one cell undergoes malignant transformation during the process that gives rise to MM, and result in a polyclonal malignancy.

Methods and results

To investigate the clonality patterns of MM, we used the HUMARA (Human Androgen Receptor) assay to examine 16 biopsies from 14 women MM patients. Out of 16 samples, one was non-informative due to skewed Lyonization in its normal adjacent tissue. Fourteen out of the 15 informative samples revealed two electrophoretically distinct methylated HUMARA alleles, the Corrected Allele Ratio (CR) calculated on the allele peak areas indicating polyclonal origin MM.

Conclusions

Our results show that MM originate as polyclonal tumors and suggest that the carcinogenic “field effect” of mineral fibers leads to several premalignant clones that give rise to these polyclonal malignancies.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-014-0301-3) contains supplementary material, which is available to authorized users.

Agonist activation of estrogen receptor beta (ERβ) sensitizes malignant pleural mesothelioma cells to cisplatin cytotoxicity

Background

Estrogen receptor (ER) β acts as a tumor suppressor in malignant mesotheliomas.

Methods

Here we explored the anti-proliferative and anti-tumorigenic efficacy of the selective ERβ agonist, KB9520, in human mesothelioma cell lines in vitro and in a mesothelioma mouse model in vivo.

Results

KB9520 showed significant anti-proliferative effect in ERβ positive human malignant pleural mesothelioma cells in vitro. Selective activation of ERβ with KB9520 sensitized the cells to treatment with cisplatin, resulting in enhanced growth inhibition and increased apoptosis. Furthermore, in CD1 nude mice mesothelioma tumor growth was significantly inhibited when KB9520 was added on top of the standard of care chemo combination cisplatin/pemetrexed, as compared to the cisplatin/pemetrexed alone group. Importantly, KB9520 exerted a protective effect to cisplatin toxicity in the non-malignant mesothelium derived MET5A cells.

Conclusions

Together, the data presented suggest that selective targeting of ERβ may be an efficacious stand-alone treatment option and/or become an important add-on to existing malignant mesothelioma therapy.

Electronic supplementary material

The online version of this article (doi:10.1186/1476-4598-13-227) contains supplementary material, which is available to authorized users.

Women with malignant pleural mesothelioma have a threefold better survival rate than men

BACKGROUND

Many studies have reported that women with malignant pleural mesothelioma (MPM) experience longer survival compared with men, whereas others have not. To date, no large population-based studies have evaluated MPM outcome and its determinants in female patients.

METHODS

All pathologically confirmed cases of MPM in the Surveillance, Epidemiology and End Results database from 1973 to 2009 were evaluated. Age, year of diagnosis, race, stage, cancer-directed surgery, radiation, and vital status were analyzed according to gender. Cox proportional hazard models were derived to assess the association between prognostic factors and survival.

RESULTS

There were 14,228 cases of MPM, of which 3,196 (22%) were women. Despite similar baseline characteristics for both genders, 5-year survival was 13.4% in women and 4.5% in men (p < 0.0001). The effect of female gender on survival persisted when stratified by age (dichotomized at 50 years), stage, or race, but differed depending on treatment. Even when adjusted for age, stage, race, and treatment, female MPM patients experienced longer survival than men (hazard ratio = 0.78; 95% confidence interval 0.75 to 0.82).

CONCLUSIONS

This large data set confirms that although MPM is less common in women, they present with similar stage and are offered similar treatment options compared with men. Nevertheless, survival is far better in women compared with men, independent of confounders such as age, stage, and treatment. Differences in asbestos exposure, tumor biology, and the impact of circulating hormones on host response must be investigated to understand this survival advantage and improve prognosis for patients of both genders.

Exemestane blocks mesothelioma growth through downregulation of cAMP, pCREB and CD44 implicating new treatment option in patients affected by this disease

Background

Recent evidence suggests that aromatase may be involved in the pathogenesis of malignant mesothelioma. Here, we evaluated the effect of exemestane, an inhibitor of aromatase, in the treatment of mesothelioma using in vitro and in vivo preclinical models.

Results

We show a significant reduction of cell proliferation, survival, migration and block of cells in S phase of cell cycle in mesothelioma cells upon exemestane treatment. Moreover, we find that CD44, which is involved in mesothelioma cells migration, was modulated by exemestane via cAMP and pCREB. Most importantly, in mice mesothelioma xenograft exemestane causes a significant decrease in tumor size and the association pemetrexed/exemestane is more effective than pemetrexed/cisplatin.

Conclusion

The preclinical mesothelioma model suggests that exemestane might be beneficial in mesothelioma treatment.

Malignant pleural mesothelioma incidence and survival in the Republic of Ireland 1994-2009

OBJECTIVE

Malignant pleural mesothelioma (MPM) is a rare malignancy associated with exposure to asbestos. The protracted latent period of MPM means that its incidence has continued to rise across Europe after the introduction of restrictions on asbestos use. In order to obtain a clearer indication of trends in the Republic of Ireland (ROI), incidence and survival were assessed based on all MPM cases reported since the establishment of the National Cancer Registry of Ireland (NCR).

METHODS

NCR recorded 337 MPM diagnoses in the ROI during 1994-2009. Survival was assessed for all cases diagnosed with adequate follow-up (n=330). Crude and European age-standardized incidence rates were calculated for all cases and for 4-year periods. A Cox model of observed (all-cause) survival was used to generate hazard ratios for the effect of: gender; age at diagnosis; diagnosis cohort; region of residence; histological type; and tumour stage. Single P-values for the variables indicated were calculated using either a stratified log-rank test or stratified trend test.

RESULTS

Over the study period the age-standardized MPM incidence in the ROI rose from 4.98cases per million (cpm) to 7.24cpm. The 1-year survival rate for all MPM cases was 29.6% (CI 24.7-34.6%). Excess mortality risk was associated with age at diagnosis (75-89 yrs vs. 55-64 yrs, HR 1.88, 95% CI 1.35-2.63, P<0.001) and tumour stage (III vs. I HR 1.57, 95% CI 1.00-2.48, P<0.05; IV vs. I HR 1.55, 95% CI 1.08-2.21, P<0.05). Age showed a significant survival trend (P<0.001) but tumour stage did not (P=0.150). There was significant heterogeneity between the survival of patients resident in different regions (P=0.027).

CONCLUSION

MPM incidence and mortality continued to rise in the ROI after the restrictions on asbestos use and the predictors of survival detected in this study are broadly consistent with those identified for other countries.

Estrogen receptor β activation impairs mitochondrial oxidative metabolism and affects malignant mesothelioma cell growth in vitro and in vivo

Estrogen receptor (ER)-β has been shown to possess a tumor suppressive effect, and is a potential target for cancer therapy. Using gene-expression meta-analysis of human malignant pleural mesothelioma, we identified an ESR2 (ERβ coding gene) signature. High ESR2 expression was strongly associated with low succinate dehydrogenase B (SDHB) (which encodes a mitochondrial respiratory chain complex II subunit) expression. We demonstrate that SDHB loss induced ESR2 expression, and that activated ERβ, by over-expression or by selective agonist stimulation, negatively affected oxidative phosphorylation compromising mitochondrial complex II and IV activity. This resulted in reduced mitochondrial ATP production, increased glycolysis dependence and impaired cell proliferation. The observed in vitro effects were phenocopied in vivo using a selective ERβ agonist in a mesothelioma mouse model. On the whole, our data highlight an unforeseen interaction between ERβ-mediated tumor suppression and energy metabolism that may be exploited to improve on the therapy for clinical management of malignant mesothelioma.

Oestrogen receptors are prognostic factors in malignant peritoneal mesothelioma

BACKGROUND

Malignant peritoneal mesothelioma (MPM) is a rare and fatal cancer. Females are found to survive longer than males after treatment, suggesting a possible involvement of hormonal factors. Estradiol is involved in cellular proliferation of a number of cancers and acts mainly through oestrogen receptors (ERs). Hence, we examined the expression of oestrogen receptors with correlation to prognosis.

METHODS

Oestrogen receptors expression was examined using immunohistochemistry on 42 paraffin-embedded sections of MPM tumours. Kaplan-Meier survival curves were analysed to determine the significance of ER expression in relation to prognosis.

RESULTS

ER-β (nuclear) was detected in 33 (79 %) patients. ER-β was also detected in the cellular cytoplasm of 9 (21 %) patients. Presence of ER-β (nuclear) was associated with favourable survival (univariate analysis, P = 0.001), whereas the presence of ER-β (cytoplasm) was associated with a poor survival (P = 0.014). Multivariate Cox regression analysis revealed the absence of ER-β (nuclear) and the presence of ER-β (cytoplasm) to be independent predictive factors for poor disease outcome (hazard ratio 5.4, 95 % confidence interval 1.86-15.75; P = 0.002 and hazard ratio 8.0, 95 % confidence interval 1.8-34; P = 0.005), respectively. ER-α (nuclear) was detected in only 4 (9 %) of patients and not statistically significant (univariate analysis, P = 0.066).

CONCLUSION

The presence of ER-β (cytoplasm) is associated with poor prognosis. The favourable survival association observed in patients with ER-β (nuclear) raises a question about the molecular mechanisms of the tumorigenic roles of ER-β in each cellular compartment and requires further studies.

Cyclooxygenase-2, epidermal growth factor receptor, and aromatase signaling in inflammation and mesothelioma

Malignant mesothelioma or mesothelioma is a rare form of cancer that develops from transformed cells originating in the mesothelium, the protective lining that covers many of the internal organs of the body. It is directly linked to asbestos exposure, which acts as a carcinogen by initiating the carcinogenic process. Because of their shape, asbestos fibers can cross the membrane barriers inside the body and cause inflammatory and fibrotic reactions. Such reactions are believed to be the mechanism by which asbestos fibers may trigger malignant mesothelioma in the pleural membrane around the lungs. Carcinogens are known to modulate the transcription factors, antiapoptotic proteins, proapoptotic proteins, protein kinases, cell-cycle proteins, cell adhesion molecules, COX-2, and growth factor signaling pathways. This article reviews recent studies regarding some malignant mesothelioma molecular targets not only for cancer prevention but also for cancer therapy.

Estrogen inhibits renal cell carcinoma cell progression through estrogen receptor-β activation

Renal cell carcinoma (RCC) originates in the lining of the proximal convoluted tubule and accounts for approximately 3% of adult malignancies. The RCC incidence rate increases annually and is twofold higher in males than in females. Female hormones such as estrogen may play important roles during RCC carcinogenesis and result in significantly different incidence rates between males and females. In this study, we found that estrogen receptor β (ERβ) was more highly expressed in RCC cell lines (A498, RCC-1, 786-O, ACHN, and Caki-1) than in breast cancer cell lines (MCF-7 and HBL-100); however, no androgen receptor (AR) or estrogen receptor α (ERα) could be detected by western blot. In addition, proliferation of RCC cell lines was significantly decreased after estrogen (17-β-estradiol, E2) treatment. Since ERβ had been documented to be a potential tumor suppressor gene, we hypothesized that estrogen activates ERβ tumor suppressive function, which leads to different RCC incidence rates between males and females. We found that estrogen treatment inhibited cell proliferation, migration, invasion, and increased apoptosis of 786-O (high endogenous ERβ), and ERβ siRNA-induced silencing attenuated the estrogen-induced effects. Otherwise, ectopic ERβ expression in A498 (low endogenous ERβ) increased estrogen sensitivity and thus inhibited cell proliferation, migration, invasion, and increased apoptosis. Analysis of the molecular mechanisms revealed that estrogen-activated ERβ not only remarkably reduced growth hormone downstream signaling activation of the AKT, ERK, and JAK signaling pathways but also increased apoptotic cascade activation. In conclusion, this study found that estrogen-activated ERβ acts as a tumor suppressor. It may explain the different RCC incidence rates between males and females. Furthermore, it implies that ERβ may be a useful prognostic marker for RCC progression and a novel developmental direction for RCC treatment improvement.