Contents of endometriotic cysts, especially the high concentration of free iron, are a possible cause of carcinogenesis in the cysts through the iron-induced persistent oxidative stress

The Role of Oxidative Stress and Membrane Transport Systems during Endometriosis: A Fresh Look at a Busy Corner

Endometriosis is a condition characterized by the presence of endometrial tissue outside the uterine cavity, leading to a chronic inflammatory reaction. It is one of the most widespread gynecological diseases with a 10-15% prevalence in the general female population, rising up to 30-45% in patients with infertility. Although it was first described in 1860, its etiology and pathogenesis are still unclear. It is now accepted that inflammation plays a central role in the development and progression of endometriosis. In particular, it is marked by an inflammatory process associated with the overproduction of an array of inflammatory mediators such as prostaglandins, metalloproteinases, cytokines, and chemokines. In addition, the growth and adhesion of endometrial cells in the peritoneal cavity due to reactive oxygen species (ROS) and free radicals lead to disease onset, its ensuing symptoms-among which pain and infertility. The aim of our review is to evaluate the role of oxidative stress and ROS in the pathogenesis of endometriosis and the efficacy of antioxidant therapy in the treatment and mitigation of its symptoms.

Serum Iron Levels Decreased in Patients with HBV-Related Hepatocellular Carcinoma, as a Risk Factor for the Prognosis of HBV-Related HCC

Background: Hepatocellular carcinoma (HCC) is common and the second leading causes of cancer-related deaths. HCC usually occurs on the basis of chronic liver diseases. At present, the study of iron metabolism in chronic liver diseases was limited to chronic HCV infection, nonalcoholic fatty liver disease, and alcoholic liver disease. This study aimed to investigate the effect of serum iron levels on the progression of chronic HBV infection and the relationship with the prognosis of HBV-related HCC. Methods: A respective study involving 277 healthy individuals as controls (HC), 295 patients with chronic hepatitis B (CHB), 224 patients with HBV-related liver cirrhosis (HBV-related LC), and 586 patients with HBV- related HCC were enrolled in this study. Hematological parameters, HBVDNA and liver biochemistry were analyzed. Child-Pugh grade and BCLC stage of the HBV-related HCC patients were calculated. Results: The serum iron levels were lowest in the HBV- related HCC group as compared with HC, CHB, and HBV-related LC groups (35.07 ± 6.97, 27.37 ± 10.26, 24.53 ± 10.36 vs. 17.90 ± 0.14, P < 0.001). Strikingly, serum iron levels were lowest in HBV- related HCC patients with tumor size more than 10 cm as compared with HBV- related HCC patients with tumor size smaller than 3, 3-5, and 5-10 cm by subgroup analysis (22.12 ± 0.94, 21.44 ± 1.41, 15.65 ± 0.98 vs. 13.36 ± 1.15, P < 0.001). Serum iron levels significantly decreased with worsening Child-Pugh grades and BCLC stages in HBV-related HCC group. In addition, serum iron levels was positively correlated with Retinol-Binding Protein, total bile acid, hemoglobin, and lymphocyte and negatively correlated with white blood cell (WBC) and platelet in HBV- related HCC group. ROC curve analysis showed serum iron levels at 15.1 μmol/L as the optimal cut-off point for determining the survival of HBV-related HCC. By the Cox regression model analysis, serum iron levels <15.1 μmol/l together with higher AFP levels, worse BCLC stages, and larger tumor size showed higher mortality of HBV-related HCC patients (hazard ratio = 2.280, 95% confidence interval, 1.815-2.865; P < 0.001). Conclusions: Serum iron levels affected the progression of chronic HBV infection. The prognosis of HBV- related HCC patients with serum iron levels <15.1 μmol/l together with higher AFP levels, worse BCLC stages, and larger tumor lesion were poor.

Impact of endometriosis on risk of further gynaecological surgery and cancer: a national cohort study

OBJECTIVE

To evaluate the long-term risk of further gynaecological surgery and cancer in women with endometriosis.

DESIGN

Cohort study.

SETTING

Scotland.

PARTICIPANTS

281 937 women with nearly 5 million person years (4 923 628) of follow up from 1981 to 2010.

METHODS

In this national population-based study we compared 17 834 women with a new surgical diagnosis of endometriosis with 83 303 women with no evidence of endometriosis at laparoscopy, 162 966 women who underwent laparoscopic sterilisation, and 17 834 age-matched women from the general population. Cox proportional hazards regression was used to calculate crude and adjusted hazard ratios with 95% confidence intervals.

MAIN OUTCOME MEASURES

Risk of further gynaecological surgery, number and type of repeat surgery and time to repeat surgery from the diagnosis of endometriosis. Cancer outcomes included subsequent risk of all cancer, gynaecological and non-gynaecological cancers.

RESULTS

Women with endometriosis had a significantly higher risk of further surgery when compared with women with no evidence of endometriosis at laparoscopy [hazard ratio (HR) 1.69, 95% (confidence interval) CI 1.65-1.73], women who had undergone laparoscopic sterilisation (HR 3.30, 95% CI 3.23-3.37) and age-matched women from the general population (HR 5.95, 95% CI 5.71-6.20). They also have an increased risk of ovarian cancer when compared with general population counterparts (HR 1.77, 95% CI 1.08-2.89) or those with laparoscopic sterilisation (HR 1.75, 95% CI 1.2-2.45).

CONCLUSION

Women with surgically diagnosed endometriosis face an increased risk of multiple surgery. They have a higher chance of developing ovarian cancer in comparison with the general population and women with laparoscopic sterilisation.

TWEETABLE ABSTRACT

Women with endometriosis face an increased risk of recurrent surgery and developing ovarian cancer.

Expression and function of nuclear receptor coactivator 4 isoforms in transformed endometriotic and malignant ovarian cells

Iron is proposed to contribute to the transition from endometriosis to specific subtypes of ovarian cancers (OVCAs). Regulation of intracellular iron occurs via a ferritinophagic process involving NCOA4 (Nuclear Receptor Coactivator 4), represented by two major isoforms (NCOA4α and NCOA4β), whose contribution to ovarian cancer biology remains uninvestigated. We thus generated transformed endometriotic cells (via HRAS^V12A, c-MYC^T58A, and p53 inactivation) whose migratory potential was increased in response to conditioned media from senescent endometriotic cells. We identified elevated NCOA4 mRNA in transformed endometriotic cells (relative to non-transformed). Knockdown of NCOA4 increased ferritin heavy chain (FTH1) and p21 protein which was accompanied by reduced cell survival while NCOA4β overexpression reduced colony formation. NCOA4α and NCOA4β mRNA were elevated in malignant versus non-malignant gynecological cells; NCOA4α protein was increased in the assessed malignant cell lines as well as in a series of OVCA subtypes (relative to normal adjacent tissues). Further, NCOA4 protein expression was regulated in a proteasome- and autophagy-independent manner. Collectively, our results implicate NCOA4 in ovarian cancer biology in which it could be involved in the transition from precursors to OVCA.

Analysis of the ectoenzymes ADA, ALP, ENPP1, and ENPP3, in the contents of ovarian endometriomas as candidate biomarkers of endometriosis

PROBLEM

The diagnosis of endometriosis, a prevalent chronic disease with a strong inflammatory component, is usually delayed due to the lack of noninvasive diagnostic tests. Purinergic signaling, a key cell pathway, is altered in many inflammatory disorders. The aim of the present work was to evaluate the levels of adenosine deaminase (ADA), alkaline phosphatase (ALP), ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1), and ENPP3, elements of purinergic signaling, as biomarker candidates for endometriosis.

METHOD OF STUDY

A case-control comparative study was conducted to determine ADA, ALP, ENPP1 and ENPP3 levels in echo-guided aspirated fluids of endometriomas (case group) and simple ovarian cysts (control group) using the ELISA technique.

RESULTS

Adenosine deaminase, ALP, ENPP1, and ENPP3 were present and quantifiable in the contents of endometriomas and simple cysts. There were significant differences in ADA and ENPP1 levels in endometriomas in comparison with simple cysts (2787 U/L and 103.9 ng/mL more in endometriomas, for ADA and ENPP1, respectively). Comparisons of ALP and ENPP3 levels between the two groups did not reveal significant differences.

CONCLUSION

The ectoenzymes ADA and ENPP1 are biomarker candidates for endometriosis.

The peritoneum: healing, immunity, and diseases

The peritoneum defines a confined microenvironment, which is stable under normal conditions, but is exposed to the damaging effect of infections, surgical injuries, and other neoplastic and non-neoplastic events. Its response to damage includes the recruitment, proliferation, and activation of a variety of haematopoietic and stromal cells. In physiological conditions, effective responses to injuries are organized; inflammatory triggers are eliminated; inflammation quickly abates; and the normal tissue architecture is restored. However, if inflammatory triggers are not cleared, fibrosis or scarring occurs and impaired tissue function ultimately leads to organ failure. Autoimmune serositis is characterized by the persistence of self-antigens and a relapsing clinical pattern. Peritoneal carcinomatosis and endometriosis are characterized by the persistence of cancer cells or ectopic endometrial cells in the peritoneal cavity. Some of the molecular signals orchestrating the recruitment of inflammatory cells in the peritoneum have been identified in the last few years. Alternative activation of peritoneal macrophages was shown to guide angiogenesis and fibrosis, and could represent a novel target for molecular intervention. This review summarizes current knowledge of the alterations to the immune response in the peritoneal environment, highlighting the ambiguous role played by persistently activated reparative macrophages in the pathogenesis of common human diseases. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Iron overload and altered iron metabolism in ovarian cancer

Iron is an essential element required for many processes within the cell. Dysregulation in iron homeostasis due to iron overload is detrimental. This nutrient is postulated to contribute to the initiation of cancer; however, the mechanisms by which this occurs remain unclear. Defining how iron promotes the development of ovarian cancers from precursor lesions is essential for developing novel therapeutic strategies. In this review, we discuss (1) how iron overload conditions may initiate ovarian cancer development, (2) dysregulated iron metabolism in cancers, (3) the interplay between bacteria, iron, and cancer, and (4) chemotherapeutic strategies targeting iron metabolism in cancer patients.

Clear cell and endometrioid carcinomas: are their differences attributable to distinct cells of origin?

Endometrial epithelium is the presumed tissue of origin for both eutopic and endometriosis-derived clear cell and endometrioid carcinomas. We had previously hypothesized that the morphological, biological and clinical differences between these carcinomas are due to histotype-specific mutations. Although some mutations and genomic landscape features are more likely to be found in one of these histotypes, we were not able to identify a single class of mutations that was exclusively present in one histotype and not the other. This lack of genomic differences led us to an alternative hypothesis that these cancers could arise from distinct cells of origin within endometrial tissue, and that it is the cellular context that accounts for their differences. In a proteomic screen, we identified cystathionine γ-lyase (CTH) as a marker for clear cell carcinoma, as it is expressed at high levels in clear cell carcinomas of the ovary and endometrium. In the current study, we analysed normal Müllerian tissues, and found that CTH is expressed in ciliated cells of endometrium (both eutopic endometrium and endometriosis) and fallopian tubes. We then demonstrated that other ciliated cell markers are expressed in clear cell carcinomas, whereas endometrial secretory cell markers are expressed in endometrioid carcinomas. The same differential staining of secretory and ciliated cells was demonstrable in a three-dimensional organoid culture system, in which stem cells were stimulated to differentiate into an admixture of secretory and ciliated cells. These data suggest that endometrioid carcinomas are derived from cells of the secretory cell lineage, whereas clear cell carcinomas are derived from, or have similarities to, cells of the ciliated cell lineage. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Role of Oxidative Stress in Epigenetic Modification in Endometriosis

Aberrant DNA methylation and histone modification are associated with an increased risk of reproductive disorders such as endometriosis. However, a cause-effect relationship between epigenetic mechanisms and endometriosis development has not been fully determined. This review provides current information based on oxidative stress in epigenetic modification in endometriosis. This article reviews the English-language literature on epigenetics, DNA methylation, histone modification, and oxidative stress associated with endometriosis in an effort to identify epigenetic modification that causes a predisposition to endometriosis. Oxidative stress, secondary to the influx of hemoglobin, heme, and iron during retrograde menstruation, is involved in the expression of CpG demethylases, ten-eleven translocation, and jumonji (JMJ). Ten-eleven translocation and JMJ recognize a wide range of endogenous DNA methyltransferases (DNMTs). The increased expression levels of DNMTs may be involved in the subsequent downregulation of the decidualization-related genes. This review supports the hypothesis that there are at least 2 distinct phases of epigenetic modification in endometriosis: the initial wave of iron-induced oxidative stress would be followed by the second big wave of epigenetic modulation of endometriosis susceptibility genes. We summarize the recent advances in our understanding of the underlying epigenetic mechanisms focusing on oxidative stress in endometriosis.

Iron regulatory protein 2 in ovarian endometrial cysts

Ovarian endometrial cysts cause some kinds of ovarian cancer, and iron is considered as one factor of carcinogenesis. In contrast, hypoxia is associated with progression, angiogenesis, metastasis, and resistance to therapy in cancer. We investigated hypoxia-induced perturbation of iron homeostasis in terms of labile iron, iron deposition, and iron regulatory protein (IRP) in ovarian endometrial cysts. Iron deposition, expression of IRPs, and a protein marker of hypoxia in human ovarian endometrial cysts were analyzed histologically. The concentration of free iron and the pO₂ level of the cyst fluid of human ovarian cysts (n = 9) were measured. The expression of IRP2 under hypoxia was investigated in vitro by using Ishikawa cells as a model of endometrial cells. Iron deposition and the expression of IRP2 and Carbonic anhydrase 9 (CA9) were strong in endometrial stromal cells in the human ovarian endometrial cysts. The average concentration of free iron in the cyst fluid was 8.1 ± 2.9 mg/L, and the pO₂ was 22.4 ± 5.2 mmHg. A cell-based study using Ishikawa cells revealed that IRP2 expression was decreased by an overload of Fe(II) under normoxia but remained unchanged under hypoxia even in the presence of excess Fe(II). An increase in the expression of IRP2 caused upregulation of intracellular iron as a result of the response to iron deficiency, whereas the protein was degraded under iron-rich conditions. We found that iron-rich regions existed in ovarian endometrial cysts concomitantly with the high level of IRP2 expression, which should generally be decomposed upon an overload of iron. We revealed that an insufficient level of oxygen in the cysts is the main factor for the unusual stabilization of IRP2 against iron-mediated degradation, which provides aberrant uptake of iron in ovarian endometrial stromal cells and can potentially lead to carcinogenesis.

Subtypes of Ovarian Cancer and Ovarian Cancer Screening

Ovarian cancer is the foremost cause of gynecological cancer death in the developed world, as it is usually diagnosed at an advanced stage. In this paper we discuss current issues, the efficacy and problems associated with ovarian cancer screening, and compare the characteristics of ovarian cancer subtypes. There are two types of ovarian cancer: Type I carcinomas, which are slow-growing, indolent neoplasms thought to arise from a precursor lesion, which are relatively common in Asia; and Type II carcinomas, which are clinically aggressive neoplasms that can develop de novo from serous tubal intraepithelial carcinomas (STIC) and/or ovarian surface epithelium and are common in Europe and the USA. One of the most famous studies on the subject reported that annual screening using CA125/transvaginal sonography (TVS) did not reduce the ovarian cancer mortality rate in the USA. In contrast, a recent study in the UK showed an overall average mortality reduction of 20% in the screening group. Another two studies further reported that the screening was associated with decreased stage at detection. Theoretically, annual screening using CA125/TVS could easily detect precursor lesions and could be more effective in Asia than in Europe and the USA. The detection of Type II ovarian carcinoma at an early stage remains an unresolved issue. The resolving power of CA125 or TVS screening alone is unlikely to be successful at resolving STICs. Biomarkers for the early detection of Type II carcinomas such as STICs need to be developed.

Genetic risk factors for ovarian cancer and their role for endometriosis risk

OBJECTIVE

Several genetic variants have been validated as risk factors for ovarian cancer. Endometriosis has also been described as a risk factor for ovarian cancer. Identifying genetic risk factors that are common to the two diseases might help improve our understanding of the molecular pathogenesis potentially linking the two conditions.

METHODS

In a hospital-based case-control analysis, 12 single nucleotide polymorphisms (SNPs), validated by the Ovarian Cancer Association Consortium (OCAC) and the Collaborative Oncological Gene-environment Study (COGS) project, were genotyped using TaqMan® OpenArray™ analysis. The cases consisted of patients with endometriosis, and the controls were healthy individuals without endometriosis. A total of 385 cases and 484 controls were analyzed. Odds ratios and P values were obtained using simple logistic regression models, as well as from multiple logistic regression models with adjustment for clinical predictors.

RESULTS

rs11651755 in HNF1B was found to be associated with endometriosis in this case-control study. The OR was 0.66 (95% CI, 0.51 to 0.84) and the P value after correction for multiple testing was 0.01. None of the other genotypes was associated with a risk for endometriosis.

CONCLUSIONS

As rs11651755 in HNF1B modified both the ovarian cancer risk and also the risk for endometriosis, HNF1B may be causally involved in the pathogenetic pathway leading from endometriosis to ovarian cancer.

[Conservative management of endometrioma in women undergoing in vitro fertilization]

Endometriosis is a chronic disease. The pathogenesis is actually still unclear. Endometriosis is responsible for infertility and/or pelvic pain. One of the most important features of the disease is the heterogeneity (clinical and anatomical). Among the different phenotypes of endometriosis, the ovarian endometrioma seems to most important lesion in the management of endometriosis-related infertility. Surgical treatment is associated to a decrease of the ovarian reserve and a potential detrimental effect on in vitro fecondation (IVF) outcomes. Thus, the choice between conservative or surgical management of endometrioma before IVF is actually debated. The advantages and drawback of surgical and conservative management should be discussed before to plan the treatment. In the present review, we aimed at assessing the risks of a conservative management of endometrioma as compared to surgery before IVF.

CCNE1 copy-number gain and overexpression identify ovarian clear cell carcinoma with a poor prognosis

Ovarian clear cell carcinoma is a unique type of ovarian cancer, often derived from endometriosis, and advanced-stage disease has a dismal prognosis primarily due to the resistance to conventional chemotherapy. Previous studies have shown frequent somatic mutations in ARID1A, PIK3CA, hTERT promoter, and amplification of ZNF217; however, the molecular alterations that are associated with its aggressiveness remain largely unknown. This study examined and compared cyclin E1 expression in endometriosis-related ovarian tumors, with the aim of determining the relationship between hTERT mutations and ARID1A expression and evaluating the effects of these molecular alterations on patient survival. We performed immunohistochemistry on 207 tumors [clear cell carcinoma (n=120), endometrioid carcinoma (n=49), and seromucinous tumors (n=38)], followed by two-color fluorescence in situ hybridization (n=88) and compared with ARID1A expression and hTERT promoter mutations in the same samples. Cyclin E1 overexpression and CCNE1 copy-number gain occurred in 23.3% and 14.8% of ovarian clear cell carcinomas, respectively, but they were not detected in any of the other endometriosis-related tumors. All cases with CCNE1 copy-number gain demonstrated an intense cyclin E1 immunoreactivity (P<0.001). Cyclin E1 overexpression was positively correlated with hTERT promoter mutations (P=0.01), but not with the loss of ARID1A expression. A multivariate analysis revealed that CCNE1 overexpression predicts poor overall survival, even after adjusting for stage and age. Specifically, CCNE1 overexpression and copy-number gain were both correlated with a poor outcome in patients with stage I disease. Moreover, the subset with CCNE1 overexpression and ARID1A retention demonstrated the worst outcome. Our findings suggest that gene copy-number gain and upregulation of CCNE1 occur in ovarian clear cell carcinoma and are associated with a worse clinical outcome, dictating the survival of early-stage patients, and that these molecular alterations are unique to clear cell carcinoma among different types of endometriosis-related ovarian neoplasms.

Genome-wide analysis of gynecologic cancer: The Cancer Genome Atlas in ovarian and endometrial cancer

Cancer typically develops due to genetic abnormalities, but a single gene abnormality cannot completely account for the onset of cancer. The Cancer Genome Atlas (CGA) project was conducted for the cross-sectional genome-wide analysis of numerous genetic abnormalities in various types of cancer. This approach has facilitated the identification of novel AT-rich interaction domain 1A gene mutations in ovarian clear cell carcinoma, frequent tumor protein 53 (TP53) gene mutations in high-grade ovarian serous carcinoma, and Kirsten rat sarcoma and B-rapidly accelerated fibrosarcoma proto-oncogene, serine/threonine kinase gene mutations in low-grade ovarian serous carcinoma. Genome-wide analysis of endometrial cancers has led to the establishment of four subgroups: Polymerase ultramutated, microsatellite instability hypermutated, genome copy-number low and genome copy-number high. These results may facilitate the improvement of the prediction of patient prognosis and therapeutic sensitivity in various types of gynecologic cancer. The enhanced use of currently available therapeutic agents and the development of novel drugs may be facilitated by the novel classification of ovarian cancer based on TP53 mutations, the efficacy of poly (ADP-ribose) polymerase inhibitors for tumors with breast cancer 1/2 mutations and the effect of phosphoinositide-3-kinase (PI3K)/mammalian target of rapamycin inhibitors for tumors with mutations in the PI3K/protein kinase B signaling pathway. Important results have been revealed by genome-wide analyses; however, the pathogenic underlying mechanisms of gynecologic cancer will require further studies and multilateral evaluation using epigenetic, transcriptomic and proteomic analyses, in addition to genomic analysis.

Effects of Supplementation of Human Endometriotic Fluids on In Vitro Mouse Preantral Follicle Culture

This study aimed to investigate the potential detrimental effect of human endometriotic fluids (EFs) on in vitro growth of mouse preantral follicles. Preantral follicles (isolated from ovaries of 7- to 8-week-old mice) were cultured in growth medium for 10 days and then in maturation medium for 2 days. During in vitro culture, EF supernatants (0%, 2.5%, 5%, and 10%) were supplemented. Meiotic spindle integrity of metaphase II (MII) oocytes was analyzed. Hormone (17β-estradiol and anti-Müllerian hormone [AMH]) levels in the final spent media were measured by enzyme-linked immunosorbent assay. The survival rates of follicles at day 10 were significantly lower in 3 EF-supplemented groups (56.1%, 30.6%, and 6.2%; 83.6% in the nonsupplemented group). The production of total oocytes per initiated follicle was also significantly lower in the 3 EF-supplemented groups (34.7%, 18.4%, and 4.1%; 68.1% in the nonsupplemented group). Proportions of the oocyte with normal spindles were significantly lower in the 3 EF-supplemented groups (10%, 0% and 0%; 52% in the nonsupplemented group). In the final spent media, the level of 17β-estradiol was significantly lower only in the 10% EF-supplemented group, and the level of AMH was significantly lower in all 3 EF-supplemented groups, when compared with the nonsupplemented group. During in vitro culture of mouse preantral follicles, the survival rate, oocyte acquisition, spindle integrity of MII oocytes, and AMH production were greatly affected by EF supplementation. These findings suggest a possibility of detrimental effects of endometriotic cysts on folliculogenesis in adjacent ovarian tissues.

Endometriotic cyst fluid induces reactive oxygen species (ROS) in human immortalized epithelial cells derived from ovarian endometrioma

OBJECTIVES

Endometriotic cyst fluid (ECF) contains a large amount of reactive oxygen species (ROS), and endometriotic cysts are exposed to strong oxidative stress, which may cause malignant transformation. In this study, ROS production by ECF was clinically analysed.

METHODS

Human immortalized epithelial cells derived from ovarian endometrioma (EMosis-CC/TERT 1) were treated with ECF. In addition, ROS production in EMosis-CC/TERT 1 was measured, and its clinical significance was analysed.

RESULTS

A total of 38 ECF samples were obtained from patients diagnosed with endometriotic cysts. In EMosis-CC/TERT1, significantly higher levels of ROS were induced by ECF than by the vehicle control and ferric nitrilotriacetate. There were no significant differences in ROS production by laterality and preoperative serum CA125 values. There were several patients whose cyst sizes were approximately 5 cm and had relatively high ROS production. Production of ROS by ECF was relatively higher in patients older than 40 years of age than in those younger than 40.

DISCUSSION

Our study revealed that ROS are highly produced by ECF in EMosis-CC/TERT1 cells; therefore, exposure to ECF induced strong oxidative stress. Development of a therapeutic strategy to reduce ROS production might be useful for preventing malignant transformation of endometriotic cysts.

Ferroportin mRNA is down-regulated in granulosa and cervical cells from infertile women

OBJECTIVE

To explore the relationship between iron and infertility by investigating iron-related gene expression in granulosa and uterine cervical cells.

DESIGN

Case-control study.

SETTING

Two tertiary hospitals.

PATIENT(S)

Two independent cohorts of fertile (n = 18 and n = 17) and infertile (n = 31 and n = 35) women.

INTERVENTION(S)

In vitro fertilization.

MAIN OUTCOME MEASURE(S)

Gene expression levels of ferritin light chain (FTL), ferritin heavy chain (FTH), transferrin receptor (TFRC), and ferroportin (SLC40A1) mRNA were analyzed in granulosa and cervical cells.

RESULT(S)

In the first cohort, fertile and infertile women were similar in body mass index. Ferroportin mRNA levels were decreased in granulosa cells from infertile women in parallel with increased serum hepcidin levels. A positive association between ferroportin and TFRC mRNA, a gene associated with intracellular iron deficiency, was observed only in granulosa cells from fertile women. The major findings were replicated in a second independent cohort.

CONCLUSION(S)

Ferroportin mRNAs and circulating hepcidin identify a subset of infertile women and may constitute a target for therapy.

Transverse Relaxation Rate of Cyst Fluid Can Predict Malignant Transformation of Ovarian Endometriosis

Purpose:

Heme and iron accumulation due to repeated hemorrhage in endometriosis may contribute to a pivotal role in carcinogenesis. We evaluate the clinical application of MR relaxometry in a series of ovarian endometriosis (OE) and endometriosis-associated ovarian cancer (EAOC).

Materials and Methods:

A prospective study of diagnostic accuracy was conducted among 82 patients (67 OE and 15 EAOC) to compare MR relaxometry and biochemical measurement of cyst fluid total iron concentration. Transverse relaxation rate R2 value was determined using a single-voxel, multi-echo MR sequence (HISTO) by a 3T-MR system. Phantom experiments were also performed to assess the correlation between the ex vivo R2 values and total iron concentrations.

Results:

Both the results of phantom experiments and in vivo human data confirmed that in vivo R2 values were highly correlated with total iron concentrations. Compared to OE, EAOC exhibit decreased in vivo R2 values and total iron levels, regardless of their age, menopausal status and cyst size. The use of in vivo R2 values retained excellent accuracy in distinguishing EAOC versus OE (sensitivity and specificity: 86% and 94%).

Conclusions:

We have demonstrated that MR relaxometry provides a noninvasive predictive tool to discriminate between EAOC and OE.

Relationship between iron overload and nonalcoholic fatty liver disease: An update

As a component of the multiple hits, iron overload plays an important role in the development of nonalcoholic fatty liver disease (NAFLD). Iron overload could affect glucose, lipid, energy metabolism and inflammatory reaction. This paper reviews the relationship between iron overload and nonalcoholic fatty liver disease, in order to clarify how and why iron overload influences the progression of NAFLD.

Metabolic alterations caused by HNF1β expression in ovarian clear cell carcinoma contribute to cell survival

HNF1β is expressed exclusively in ovarian clear cell carcinoma (OCCC) and not in other ovarian cancers, regarded as a hallmark of this tumor. This implies its central role in the unique character of OCCC, including resistance to chemotherapy, but its exact role and influence in cancer biology or the molecular bases of its function are largely unknown. Using comprehensive metabolome analysis of HNF1β_shRNA-stable cell lines, we show here that HNF1β drastically alters intracellular metabolism, especially in direction to enhance aerobic glycolysis, so called the “Warburg effect”. The consequence of the metabolic change contributed cell survival under stresses such as hypoxia and chemo-reagent, only when sufficient glucose supply was available. Augmented cell survival was based on the reduced ROS activity derived from metabolic alteration such as shift from oxidative phosphorylation to glycolysis and increased intracellular anti-oxidant, glutathione (GSH). One of the cystine transporters, rBAT is likely to play a major role in this GSH increase. These data suggest that HNF1β, possibly induced by stressful microenvironment in the endometriotic cyst, confers survival advantage to the epithelial cells, which leads to the occurrence of OCCC, a chemo-resistant phenotype of ovarian cancer.

Polymerase Epsilon Exonuclease Domain Mutations in Ovarian Endometrioid Carcinoma

OBJECTIVE

Polymerase epsilon (POLE) is a DNA polymerase with a proofreading (exonuclease) domain, responsible for the recognition and excision of mispaired bases, thereby allowing high-fidelity DNA replication to occur. The Cancer Genome Atlas research network recently identified an ultramutated group of endometrial carcinomas, characterized by mutations in POLE, and exceptionally high substitution mutation rates. These POLE mutated endometrial tumors were almost exclusively of the endometrioid histotype. The prevalence and patterns of POLE mutated tumors in endometrioid carcinomas of the ovary, however, have not been studied in detail.

MATERIALS AND METHODS

In this study, we investigate the frequency of POLE exonuclease domain mutations in a series of 89 ovarian endometrioid carcinomas.

RESULTS

We found POLE mutations in 4 of 89 (4.5%) cases, occurring in 3 of 23 (13%) International Federation of Gynecology and Obstetrics (FIGO) grade 1, 1 of 43 (2%) FIGO grade 2, and 0 of 23 (0%) FIGO grade 3 tumors. All mutations were somatic missense point mutations, occurring at the commonly reported hotspots, P286R and V411L. All 3 POLE-mutated FIGO grade 1 tumors displayed prototypical histology, and the POLE-mutated FIGO grade 2 tumor displayed morphologic heterogeneity with focally high-grade features. All 4 patients with POLE-mutated tumors followed an uneventful clinical course with no disease recurrence; however, this finding was not statistically significant (P = 0.59).

CONCLUSIONS

The low rate of POLE mutations in ovarian endometrioid carcinoma and their predominance within the low FIGO grade tumors are in contrast to the findings in the endometrium.

Protective effects of vitamin D3 on fimbrial cells exposed to catalytic iron damage

Background

Recently, vitamin D₃ (1alpha, 25-dihydroxyvitamin D) has shown its capability to take part in many extraskeletal functions and its serum levels have been related to patient survival rate and malignancy of many types of neoplasms, including ovarian cancers. Catalytic iron is a free circulating form of iron that is able to generate reactive oxygen species and consequently to promote a number of cellular and tissutal dysfunctions including tumorigenesis. In fertile women an important source of catalytic iron is derived from retrograde menstruation. Epithelial secretory cells from fimbriae of fallopian tubes are greatly exposed to catalytic iron derived from menstrual reflux and so represent the site of origin for most serous ovarian cancers.

The aim of this study was to assess whether vitamin D₃ can play a role in counteracting catalytic iron-induced oxidative stress in cells from fimbriae of fallopian tubes.

Methods

The cells, isolated from women undergoing isteroannessiectomy, were treated with catalytic iron 50-75-100 mM and vitamin D₃ at a concentration ranging from 0.01 to 10 nM to study cell viability, radical oxygen species production, p53, pan-Ras, Ki67 and c-Myc protein expressions through Western Blot, and immunocytochemistry or immunofluorescence analysis.

Results

The pre-treatment with vitamin D₃ 1 nM showed its beneficial effects that consists in a significant decrease in ROS production. In addition a novel finding is represented by the demonstration that pre-treatment with vitamin D₃ is also able to significantly counteract tumoral biomarkers activation, such as p53, pan-Ras, Ki67 and c-Myc, and consequently the catalytic iron-induced cellular injury.

Conclusions

This study demonstrates for the first time that vitamin D₃ plays an important role in preventing catalytic iron-dependent oxidative stress in cultured fimbrial cells. These results support the hypothesis that vitamin D₃ could counteract carcinogenic changes induced by catalytic iron.

Metal-catalyzed oxidation of 2-alkenals generates genotoxic 4-oxo-2-alkenals during lipid peroxidation

Lipid peroxidation products react with cellular molecules, such as DNA bases, to form covalent adducts, which are associated with aging and disease processes. Since lipid peroxidation is a complex process and occurs in multiple stages, there might be yet unknown reaction pathways. Here, we analyzed comprehensively 2'-deoxyguanosine (dG) adducts with oxidized arachidonic acid using liquid chromatography-tandem mass spectrometry and found the formation of 7-(2-oxo-hexyl)-etheno-dG as one of the major unidentified adducts. The formation of this adduct was reproduced in the reaction of dG with 2-octenal and predominantly with 4-oxo-2-octenal (OOE). We also found that other 2-alkenals (with five or more carbons) generate corresponding 4-oxo-2-alkenal-type adducts. Importantly, it was found that transition metals enhanced the oxidation of C4-position of 2-octenal, leading to the formation of OOE-dG adduct. These findings demonstrated a new pathway for the formation of 4-oxo-2-alkenals during lipid peroxidation and might provide a mechanism for metal-catalyzed genotoxicity.

Kinase signalling pathways in endometriosis: potential targets for non-hormonal therapeutics

BACKGROUND

Endometriosis, the growth of endometrial tissue outside the uterine cavity, is associated with chronic pelvic pain, subfertility and an increased risk of ovarian cancer. Current treatments include the surgical removal of the lesions or the induction of a hypoestrogenic state. However, a reappearance of the lesion after surgery is common and a hypoestrogenic state is less than optimal for women of reproductive age. Additional approaches are required. Endometriosis lesions exist in a unique microenvironment characterized by increased concentrations of hormones, inflammation, oxidative stress and iron. This environment influences cell survival through the binding of membrane receptors and a subsequent cascading activation of intracellular kinases that stimulate a cellular response. Many of these kinase signalling pathways are constitutively activated in endometriosis. These pathways are being investigated as therapeutic targets in other diseases and thus may also represent a target for endometriosis treatment.

METHODS

To identify relevant English language studies published up to 2015 on kinase signalling pathways in endometriosis, we searched the Pubmed database using the following search terms in various combinations; 'endometriosis', 'inflammation', 'oxidative stress', 'iron', 'kinase', 'NF kappa', 'mTOR', 'MAPK' 'p38', 'JNK', 'ERK' 'estrogen' and progesterone'. Further citing references were identified using the Scopus database and finally current clinical trials were searched on the clinicaltrials.gov trial registry.

RESULTS

The current literature on intracellular kinases activated by the endometriotic environment can be summarized into three main pathways that could be targeted for treatments: the canonical IKKβ/NFκB pathway, the MAPK pathways (ERK1/2, p38 and JNK) and the PI3K/AKT/mTOR pathway. A number of pharmaceutical compounds that target these pathways have been successfully trialled in in vitro and animal models of endometriosis, although they have not yet proceeded to clinical trials. The current generation of kinase inhibitors carry a potential for adverse side effects.

CONCLUSIONS

Kinase signalling pathways represent viable targets for endometriosis treatment. At present, however, further improvements in clinical efficacy and the profile of adverse effects are required before these compounds can be useful for long-term endometriosis treatment. A better understanding of the molecular activity of these kinases, including the specific extracellular compounds that lead to their activation in endometriotic cells specifically should facilitate their improvement and could potentially lead to new, non-hormonal treatments of endometriosis.

Microbial siderophores and their potential applications: a review

Siderophores are small organic molecules produced by microorganisms under iron-limiting conditions which enhance the uptake of iron to the microorganisms. In environment, the ferric form of iron is insoluble and inaccessible at physiological pH (7.35-7.40). Under this condition, microorganisms synthesize siderophores which have high affinity for ferric iron. These ferric iron-siderophore complexes are then transported to cytosol. In cytosol, the ferric iron gets reduced into ferrous iron and becomes accessible to microorganism. In recent times, siderophores have drawn much attention due to its potential roles in different fields. Siderophores have application in microbial ecology to enhance the growth of several unculturable microorganisms and can alter the microbial communities. In the field of agriculture, different types of siderophores promote the growth of several plant species and increase their yield by enhancing the Fe uptake to plants. Siderophores acts as a potential biocontrol agent against harmful phyto-pathogens and holds the ability to substitute hazardous pesticides. Heavy-metal-contaminated samples can be detoxified by applying siderophores, which explicate its role in bioremediation. Siderophores can detect the iron content in different environments, exhibiting its role as a biosensor. In the medical field, siderophore uses the "Trojan horse strategy" to form complexes with antibiotics and helps in the selective delivery of antibiotics to the antibiotic-resistant bacteria. Certain iron overload diseases for example sickle cell anemia can be treated with the help of siderophores. Other medical applications of siderophores include antimalarial activity, removal of transuranic elements from the body, and anticancer activity. The aim of this review is to discuss the important roles and applications of siderophores in different sectors including ecology, agriculture, bioremediation, biosensor, and medicine.

Treatment of endometrioma for improving fertility

Endometrioma is a frequent clinical manifestation of endometriosis. It is controversial how endometriomas may affect women's fertility. This review addresses: the impact of the endometrioma per se and of its surgical treatment on ovarian physiology, on the ovarian reserve, on spontaneous conception and pregnancy outcomes, and on IVF/ICSI outcomes. Based on current evidence, although there are plausible biological detrimental effects on the ovarian cortex surrounding the endometrioma and an impairment of the normal ovarian physiology, the clinical impact of the endometrioma per se is not significantly altered. There is a negligible detrimental effect on ovarian reserve with spontaneous ovulation not being impaired. Conversely, surgical excision of an endometrioma reduces ovarian reserve as measured by AMH levels. Studies investigating the impact of the endometrioma per se and of its surgical treatment in women requiring IVF/ICSI show similar implantation rates, clinical pregnancy rates and live birth rates between women with endometrioma and controls.

Potential scenarios leading to ovarian cancer arising from endometriosis

OBJECTIVES

The aim of this review was to highlight recent advances in our understanding of the pathogenesis of malignant transformation of endometriosis.

METHODS

This study reviewed the English-language literature concerning basic science studies of the potential promotion of carcinogenesis.

RESULTS

Repeated episodes of hemorrhage occur in endometriosis at the onset of menstruation. Extracellular hemoglobin, heme, and iron derivatives in endometriosis cause DNA damage and mutations, which create increased cellular susceptibility to oxidant-mediated cell killing. Excess DNA damage and mutations are linked to cell death, but not carcinogenesis. In response to an oxidative and inflammatory microenvironment, endometriotic cells and macrophages secrete antioxidants that control excess oxidative stress in the surrounding environment. Exposure of endometriotic cells to a sublethal level of oxidative stress may lead to carcinogenesis. Macrophages also secrete immunosuppressive factors that lead to promotion of malignant transformation.

DISCUSSION

At least two potential scenarios could result in ovarian cancer arising from endometriosis. The first step: extracellular hemoglobin, heme, and iron cause cellular oxidative damage by promoting reactive oxygen species formation, which results in DNA damage and mutations (ovarian cancer initiation from endometriosis). The second step: cancer progression may be associated with persistent antioxidant production favoring a protumoral microenvironment.

Lipocalin 2 attenuates iron-related oxidative stress and prolongs the survival of ovarian clear cell carcinoma cells by up-regulating the CD44 variant

Ovarian clear cell carcinoma (CCC) arises from ovarian endometriosis. Intra-cystic fluid contains abundant amounts of free iron, which causes persistent oxidative stress, a factor that has been suggested to induce malignant transformation. However, the mechanisms linking oxidative stress and carcinogenesis in CCC currently remain unclear. Lipocalin 2 (LCN2), a multifunctional secretory protein, functions as an iron transporter as well as an antioxidant. Therefore, we herein examined the roles of LCN2 in the regulation of intracellular iron concentrations, oxidative stress, DNA damage, and antioxidative functions using LCN2-overexpressing (ES2), and LCN2-silenced (RMG-1) CCC cell lines. The results of calcein staining indicated that the up-regulated expression of LCN2 correlated with increases in intracellular iron concentrations. However, a DCFH-DA assay and 8OHdG staining revealed that LCN2 reduced intracellular levels of reactive oxygen species and DNA damage. Furthermore, the expression of LCN2 suppressed hydrogen peroxide-induced apoptosis and prolonged cell survival, suggesting an antioxidative role for LCN2. The expression of mRNAs and proteins for various oxidative stress-catalyzing enzymes, such as heme oxygenase (HO), superoxide dismutase (SOD), and glutathione peroxidase, was not affected by LCN2, whereas the intracellular concentration of the potent antioxidant, glutathione (GSH), was increased by LCN2. Furthermore, the expression of xCT, a cystine transporter protein, and CD44 variant 8-10 (CD44v), a stem cell marker, was up-regulated by LCN2. Although LCN2 increased intracellular iron concentrations, LCN2-induced GSH may catalyze and override oxidative stress via CD44v and xCT, and subsequently enhance the survival of CCC cells in oxidative stress-rich endometriosis.

Characteristics of follicular fluid in ovaries with endometriomas

The study of follicular fluid (FF) content nearby endometriomas may assist in elucidating pathophysiology, possible biomarkers related to this disease and the effect of endometriomas on ovarian physiology. As the question "how endometrioma may intrude the physiology of ovarian tissue?" is still open, we aimed to summarize the molecular evidence supporting the idea that endometriomas can negatively influence the content of the surrounding ovarian follicles. An alteration of the iron metabolism and an increased ROS (reactive oxygen species) generation characterize the intrafollicular environment adjacent to endometriomas. Other potentially negative effects include decreased testosterone and anti-Mullerian hormone FF levels although these have been only partially clarified. Alterations in lipid and proteomic patterns have been also observed in FF samples nearby endometriomas. The possibility that endometriomas per se may influence IVF clinical results as a consequence of the detrimental impact on the local intrafollicular environment is also discussed.

Endometriosis-associated Malignancy

Endometriosis is a common condition in women of reproductive age. According to several epidemiological studies endometriosis may be associated with increased risk of various malignancies. However, endometriosis-associated malignancy (EAM) is defined by certain histological criteria. About 80 % of EAM have been found in the ovary, whereas 20 % are localized in extragonadal sites like intestine, rectovaginal septum, abdominal wall, pleura and others. Some authors suggest that EAM arise from atypical endometriosis as an intermediate lesion between endometriosis and cancer. Moreover, a number of genetic alterations, like loss of heterozygosity (LOH), PTEN, ARID1 A and p53 mutations have been found in both endometriosis and EAM. Endometriosis-associated ovarian cancer (EAOC) is mostly a well or intermediately differentiated tumor of endometrioid or clear cell histological sub-type. Women affected by EAOC are on average five to ten years younger than non-EAOC patients; in most of the cases EAOC is a low stage disease with favorable clinical outcome. Since EAM is a rare condition systematic data on EAM are still missing. A systematic retrospective study on endometriosis-associated malignancies (EAM study) is currently being conducted by the Endometriosis Research Foundation together with the study groups on ovarian and uterine tumors of the working group for gynecological oncology (AGO) (gyn@mlk-berlin.de).

Endometriosis as a detrimental condition for granulosa cell steroidogenesis and development: From molecular alterations to clinical impact

Endometriosis is an estrogen-dependent chronic inflammatory condition that affects women in their reproductive period. Alterations in ovarian follicle morphology and function have been documented in affected women. The local intrafollicular environment has been as well examined by various groups. In the present review, we aimed to summarize the molecular evidence supporting the idea that endometriosis can negatively influence growth, steroidogenesis and the function of the granulosa cells (GCs). Reduced P450 aromatase expression, increased intracellular ROS generation and altered WNT signaling characterize the GCs of women with endometriosis. Clear evidence for an increased level of GC apoptosis has been provided in association with the downregulation of pro-survival factors. Other potentially negative effects include decreased progesterone production, locally decreased AMH production and lower inflammatory cytokine expression, although these have been only partially clarified. The possibility that endometriosis per se may influence IVF clinical results as a consequence of the detrimental impact on the local intrafollicular environment is also discussed.

Paradigm Shift in the Management Strategy for Epithelial Ovarian Cancer

The hypothesis on the pathogenesis of epithelial ovarian cancer continues to evolve. Although epithelial ovarian cancer had been assumed to arise from the coelomic epithelium of the ovarian surface, it is now becoming clearer that the majority of serous carcinomas arise from epithelium of the distal fallopian tube, whereas clear cell and endometrioid cancers arise from endometriosis. Molecular and genomic characteristics of epithelial ovarian cancer have been extensively investigated. Our understanding of pathogenesis of the various histologic types of ovarian cancer have begun to inform changes to the strategies for management of epithelial ovarian cancer, which represent a paradigm shift not only for treatment but also for prevention, which previously had not been considered achievable. In this article, we will discuss novel attempts at the prevention of high-grade serous ovarian cancer and treatment strategies for two distinct entities in epithelial ovarian cancer: low-grade serous and clear cell ovarian carcinomas, which are relatively rare and resistant to conventional chemotherapy.

ARID1A gene mutation in ovarian and endometrial cancers (Review)

The AT-rich interacting domain-containing protein 1A gene (ARID1A) encodes ARID1A, a member of the SWI/SNF chromatin remodeling complex. Mutation of ARID1A induces changes in expression of multiple genes (CDKN1A, SMAD3, MLH1 and PIK3IP1) via chromatin remodeling dysfunction, contributes to carcinogenesis, and has been shown to cause transformation of cells in association with the PI3K/AKT pathway. Information on ARID1A has emerged from comprehensive genome-wide analyses with next-generation sequencers. ARID1A mutations have been found in various types of cancer and occur at high frequency in endometriosis-associated ovarian cancer, including clear cell adenocarcinoma and endometrioid adenocarcinoma, and also occur at endometrial cancer especially in endometrioid adenocarcinoma. It has also been suggested that ARID1A mutation occurs at the early stage of canceration from endometriosis to endometriosis-associated carcinoma in ovarian cancer and also from atypical endo-metrial hyperplasia to endometrioid adenocarcinoma in endometrial cancer. Therefore, development of a screening method that can detect mutations of ARID1A and activation of the PI3K/AKT pathway might enable early diagnosis of endometriosis-associated ovarian cancers and endometrial cancers. Important results may also emerge from a current clinical trial examining a multidrug regimen of temsirolimus, a small molecule inhibitor of the PI3K/AKT pathway, for treatment of advanced ovarian clear cell adenocarcinoma with ARID1A mutation and PI3K/AKT pathway activation. Also administration of sorafenib, a multikinase inhibitor, can inhibit cancer proliferation with PIK3CA mutation and resistance to mTOR inhibitors and GSK126, a molecular-targeted drug can inhibit proliferation of ARID1A-mutated ovarian clear cell adenocarcinoma cells by targeting and inhibiting EZH2. Further studies are needed to determine the mechanism of chromatin remodeling dysregulation initiated by ARID1A mutation, to develop methods for early diagnosis, to investigate new cancer therapy targeting ARID1A, and to examine the involvement of ARID1A mutations in development, survival and progression of cancer cells.

Endometriosis as a risk factor for ovarian or endometrial cancer - results of a hospital-based case-control study

Background

No screening programs are available for ovarian or endometrial cancer. One reason for this is the low incidence of the conditions, resulting in low positive predictive values for tests, which are not very specific. One way of addressing this problem might be to use risk factors to define subpopulations with a higher incidence. The aim of this study was to investigate the extent to which a medical history of endometriosis can serve as a risk factor for ovarian or endometrial cancer.

Methods

In a hospital-based case–control analysis, the cases represented patients with endometrial or ovarian cancer who were participating in studies aimed at assessing the risk for these diseases. The controls were women between the age of 40 and 85 who were invited to take part via a newspaper advertisement. A total of 289 cases and 1016 controls were included. Using logistic regression models, it was tested whether self-reported endometriosis is a predictor of case–control status in addition to age, body mass index (BMI), number of pregnancies and previous oral contraceptive (OC) use.

Results

Endometriosis was reported in 2.1 % of the controls (n = 21) and 4.8 % of the cases (n = 14). Endometriosis was a relevant predictor for case–control status in addition to other predictive factors (OR 2.63; 95 % CI, 1.28 to 5.41).

Conclusion

This case–control study found that self-reported endometriosis may be a risk factor for endometrial or ovarian cancer in women between 40 and 85 years. There have been very few studies addressing this issue, and incorporating it into a clinical prediction model would require a more precise characterization of the risk factor of endometriosis.

Ovarian endometriosis-associated stromal cells reveal persistently high affinity for iron

Ovarian endometriosis is a recognized risk for infertility and epithelial ovarian cancer, presumably due to iron overload resulting from repeated hemorrhage. To find a clue for early detection and prevention of ovarian endometriosis-associated cancer, it is mandatory to evaluate catalytic (labile) ferrous iron (catalytic Fe(II)) and to study iron manipulation in ovarian endometriotic lesions. By the use of tissues from women of ovarian endometriosis as well as endometrial tissue from women with and without endometriosis, we for the first time performed histological analysis and cellular detection of catalytic Fe(II) with a specific fluorescent probe (HMRhoNox-M), and further evaluated iron transport proteins in the human specimens and in co-culture experiments using immortalized human eutopic/ectopic endometrial stromal cells (ESCs) in the presence or absence of epithelial cells (EpCs). The amounts of catalytic Fe(II) were higher in ectopic endometrial stromal cells (ecESCs) than in normal eutopic endometrial stromal cells (n-euESCs) both in the tissues and in the corresponding immortalized ESCs. ecESCs exhibited higher transferrin receptor 1 expression both in vivo and in vitro and lower ferroportin expression in vivo than n-euESCs, leading to sustained iron uptake. In co-culture experiments of ESCs with iron-loaded EpCs, ecESCs received catalytic ferrous iron from EpCs, but n-euESCs did not. These data suggest that ecESC play a protective role for cancer-target epithelial cells by collecting excess iron, and that these characteristics are retained in the immortalized ecESCs.

The Defensive Role of Cumulus Cells Against Reactive Oxygen Species Insult in Metaphase II Mouse Oocytes

We investigated the ability of reactive oxygen species (ROS), such as hydrogen peroxide (H(2)O(2)), hydroxyl radical ((·)OH), and hypochlorous acid (HOCl), to overcome the defensive capacity of cumulus cells and elucidate the mechanism through which ROS differentially deteriorate oocyte quality. Metaphase II mouse oocytes with (n = 1634) and without cumulus cells (n = 1633) were treated with increasing concentration of ROS, and the deterioration in oocyte quality was assessed by the changes in the microtubule morphology and chromosomal alignment. Oocyte and cumulus cell viability and cumulus cell number were assessed by indirect immunofluorescence, staining of gap junction protein, and trypan blue staining. The treated oocytes showed decreased quality as a function of increasing concentrations of ROS when compared to controls. Cumulus cells show protection against H(2)O(2) and (·)OH insult at lower concentrations, but this protection was lost at higher concentrations (>50 μmol/L). At higher H(2)O(2) concentrations, treatment dramatically influenced the cumulus cell number and viability with resulting reduction in the antioxidant capacity making the oocyte more susceptible to oxidative damage. However, cumulus cells offered no significant protection against HOCl at any concentration used. In all circumstances in which cumulus cells did not offer protection to the oocyte, both cumulus cell number and viability were decreased. Therefore, the deterioration in oocyte quality may be caused by one or more of the following: a decrease in the antioxidant machinery by the loss of cumulus cells, the lack of scavengers for specific ROS, and/or the ability of the ROS to overcome these defenses.

Ovarian clear cell carcinoma meets metabolism; HNF-1β confers survival benefits through the Warburg effect and ROS reduction

Ovarian clear cell carcinoma (OCCC) constitutes one of the subtypes of ovarian cancers, but it has unique clinical, histological and biological characteristics, one of which is chemo-resistance. It is also known to develop from endometriotic cyst, a benign ovarian tumor, at relatively high frequency. Recently, it is becoming well known that most of OCCCs express HNF1β, a transcription factor, which is closely associated with the development of liver, pancreas and kidney, as well as occurrence of familial forms of type 2 diabetes. Expression of HNF1β is now regarded as a hallmark of this tumor. Nevertheless, exact biological function of this gene in OCCC has not been clarified. We have shown in previous studies that microenvironment in endometriotic cysts contains severe oxidative stress and OCCC develops under such stressful environment as stress-resistant tumor, which may lead to chemo-resistance. We also showed that increased expression of HNF1β facilitates glucose uptake and glycolysis, which is known as Warburg effect. In the previous issue of this journal, by using comprehensive metabolome analysis, we report that HNF1β actually reduces and protects themselves from internal oxidative stress by dramatically changing cellular metabolism. In this article, we review the relevance and significance of cancer-specific metabolism and how they are associated with biological characteristics of OCCC via expression of HNF1β, along with future clinical implications of targeting cancer-specific metabolism.

Distinct β-catenin and PIK3CA mutation profiles in endometriosis-associated ovarian endometrioid and clear cell carcinomas

OBJECTIVES

We focused on the differences in molecular mechanisms in the early stages of endometriosis-associated ovarian endometrioid carcinoma (OEMCa) and ovarian clear cell carcinoma (OCCCa).

METHODS

Alterations in the β-catenin and PIK3CA genes, as well as expression of their associated markers, were investigated.

RESULTS

Mutations in exon 3 of the β-catenin gene were identified in 21 (60%) of 35 OEMCas. The mutations were also detected in the coexisting nonatypical (52.4%) and atypical (73.3%) endometriosis, and the single-nucleotide substitutions were identical in most cases. In contrast, the mutations were not identified in any of the OCCCas and their coexisting endometriosis. PIK3CA mutations were observed in 11 (31.4%) of 35 OEMCas and 10 (35.7%) of 28 OCCCas. Ten of 11 OEMCas had PIK3CA mutations in exon 9, and eight of 10 OCCCas had them in exon 20. The same mutations were also detected in the coexisting nonatypical and/or atypical endometriosis in three OEMCas and four OCCCas. In addition, significant differences in the expression of pAkt, hepatocyte nuclear factor 1β, hypoxia-inducible factor 1α, p65, and inducible nitric oxide synthase were evident between the two types of tumors and their coexisting endometriosis.

CONCLUSIONS

Distinct molecular events may occur in relatively early stages of tumorigenesis of endometriosis-associated OEMCas and OCCCas.

Endometriosis and ovarian cancer: potential benefits and harms of screening and risk-reducing surgery

Although endometriosis is well recognized as a benign gynecologic condition, its association with ovarian cancer (OVCA) has frequently been reported. Review articles on this topic are voluminous, yet there seems to be no consensus as to whether endometriosis is truly a precursor of OVCA and whether any screening or risk-reducing surgery should be instituted, on the basis of our current knowledge. In this review, published data are compiled and critically appraised. Through this critical appraisal, it seems clear that the strongest evidence seems to come from prevalence data. This type of data also suggests a reduced risk of certain histotypes (mainly type II) of OVCA in women with endometriosis. This may explain the rather moderate increase in risk as shown in epidemiologic studies. Even with this moderate increase in OVCA risk, caution should be exercised because of apparent bias in favor of publication of positive results, extensive heterogeneities among prevalence estimates, and inverse relationship between estimates and sizes of the studies. Many molecular studies are conflicting, and earlier studies showing molecular aberrations involved in genomic instability and mutation that enable malignant transformation are not replicated in later studies. Given the low incidence of OVCA and the rather moderate increase in risk of mostly type I tumors, screening seems to be ill-advised, and risk-reducing surgery such as salpingectomy with or without oophorectomy does not seem to yield any substantial benefit to women with endometriosis.

Measurement of oxidative stress in the follicular fluid of infertility patients with an endometrioma

PURPOSE

Follicular fluid (FF) might reflect the environment during follicle and oocyte growth, and an evaluation of oxidative stress in the FF might be useful in predicting oocyte quality. In order to measure the oxidative stress (OS) in the FF from a single follicle of patients with endometrioma (EM), we evaluated whether an EM might affect the environment of follicular growth.

METHODS

Between December 2011 and July 2013, 26 patients with a unilateral EM (EM group) and 29 without EM (control group) were enrolled in this study. The FF was obtained during the first puncture of follicular aspiration, and was stored at -30 °C until it was assayed. A Free Radical Elective Evaluator (WISMERLL, USA) was used to perform d-ROM and BAP tests to measure oxidative stress (U.CARR) and antioxidant power (μmol/L).

RESULTS

The d-ROM values in the EMC and control groups were 328.7 ± 97.8 and 414.9 ± 84.2, respectively, and the BAP values for the two groups were 2474.3 ± 432.0 and 2552.8 ± 435.58, respectively. These values were similar between the two groups (mean ± SD). The number of patients with a modified BAP/d-ROM ratio of <1.0 in the EM group was similar to that for the control group at 16 and 15, respectively (61.5 and 51.7 %).

CONCLUSIONS

The oxidative stress and antioxidant potential in the FF of the patients with unilateral EM showed values similar to those without an EM. Therefore, we concluded that EMs do not affect the environment for follicle growth during ART treatment.

Transcriptional upregulation of HNF-1β by NF-κB in ovarian clear cell carcinoma modulates susceptibility to apoptosis through alteration in bcl-2 expression

Hepatocyte nuclear factor-1β (HNF-1β) is a transcriptional factor that has an important role in endometriosis-ovarian clear cell carcinoma (OCCC) sequence by modulating cell kinetics and glucose metabolism. However, little is known about the detailed molecular mechanisms that govern its regulation and function. Herein, we focus on upstream and downstream regulatory factors of HNF-1β in OCCCs. In clinical samples, HNF-1β expression was positively correlated with the active form of NF-κB/p65 in OCCCs, and closely linked with a low nuclear grade and non-solid architecture. In cell lines, transfection of p65 resulted in increased HNF-1β mRNA and protein expression in TOV-21G cells (OCCC cell line with endogenous HNF-1β expression), in line with activation of the promoter, probably through interacting with the basic transcriptional machinery. Suppression of endogenous HNF-1β expression by siRNA increased apoptosis in TOV-21G cells, while treatment of Hec251 cells (endometrial carcinoma cell line with extremely low endogenous HNF-1β expression) stably overexpressing exogenous HNF-1β with doxorubicin abrogated apoptosis of the cells, along with increased ratio of bcl-2 relative to bax. Moreover, overexpression of HNF-1β led to upregulation of bcl-2 expression at the transcriptional level in TOV-21G cells, which provided evidence for a positive correlation between HNF-1β and bcl-2 expression in OCCCs. These data, therefore, suggest that association between HNF-1β and NF-κB signaling may participate in cell survival by alteration of apoptotic events, particularly in mitochondria-mediated pathways, through upregulation of bcl-2 expression in OCCCs.

Are clear cell carcinomas of the ovary and endometrium phenotypically identical? A proteomic analysis

Phenotypic differences between otherwise similar tumors arising from different gynecologic locations may be highly significant in understanding the underlying driver molecular events at each site and may potentially offer insights into differential responses to treatment. In this study, the authors sought to identify and quantify phenotypic differences between ovarian clear cell carcinoma (OCCC) and endometrial clear cell carcinoma (ECCC) using a proteomic approach. Tissue microarrays were constructed from tumor samples of 108 patients (54 ECCCs and 54 OCCCs). Formalin-fixed samples on microarray slides were analyzed by matrix-assisted laser desorption/ionization mass spectrometry, and 730 spectral peaks were generated from the combined data set. A linear mixed-effect model with random intercept was used to generate 93 (12.7%) peaks that were significantly different between OCCCs and ECCCs at the fold cutoffs of 1.5 and 0.667 and an adjusted P value cutoff of 1.0 × 10(-10). Liquid chromatography-tandem mass spectrometry was performed on selected cores from each group, and peptides identified therefrom were compared with lists of statistically significant peaks from the aforementioned linear mixed-effects model to find matches within 0.2 Da. A total of 53 candidate proteins were thus identified as being differentially expressed in OCCCs and ECCCs, 45 (85%) of which were expressed at higher levels in ECCCs than OCCCs. These proteins were functionally diverse and did not highlight a clearly dominant cellular theme or molecular pathway. Although ECCCs and OCCCs are very similar, some phenotypic differences are demonstrable. Additional studies of these differentially expressed proteins may ultimately clarify the significance of these differences.

Oxidative Stress and Antioxidant Defense in Endometriosis and Its Malignant Transformation

The aim of this study was to investigate the role of redox status in endometriosis and its malignant transformation. A search was conducted between 1990 and 2014 through the English language literature (online MEDLINE PubMed database) using the keywords endometriosis combined with malignant transformation, oxidative stress, and antioxidant defense. In benign endometriosis, autoxidation and Fenton reaction of hemoglobin from the ferrous Fe²⁺ (oxyhemoglobin) state to the ferric Fe³⁺ (methemoglobin) state lead to production of excess reactive oxygen species (ROS) such as O₂⁻ and ^∙OH. Hemoglobin, heme, and iron derivatives in endometriotic cysts cause distortion in the homeostatic redox balance. Excess oxidative stress could trigger DNA damage and cell death. In contrast, endometriosis-associated ovarian cancer (EAOC) might be associated with an effective antioxidant defense, including heme oxygenases, cytochrome P450 family, and glutathione transferase family. The pattern of redox balance supports that enhanced antioxidants may be involved in the pathogenesis of malignant transformation. In conclusion, oxidant/antioxidant balance function is a double-edged sword, promoting cell death or carcinogenesis. Upregulation of antioxidant functions in endometriotic cyst may result in restoration of cell survival and subsequent malignant transformation.