Jan Kotarski

Expression of aldehyde dehydrogenase and CD133 defines ovarian cancer stem cells

Identification of cancer stem cells is crucial for advancing cancer biology and therapy. Several markers including CD24, CD44, CD117, CD133, the G subfamily of ATP‐binding cassette transporters (ABCG), epithelial specific antigen (ESA) and aldehyde dehydrogenase (ALDH) are used to identify and investigate human epithelial cancer stem cells in the literature. We have now systemically analyzed and compared the expression of these markers in fresh ovarian epithelial carcinomas. Although the expression levels of these markers were unexpectedly variable and partially overlapping in fresh ovarian cancer cells from different donors, we reliably detected important levels of CD133 and ALDH in the majority of fresh ovarian cancer. Furthermore, most of these stem cell markers including CD133 and ALDH were gradually lost following in vitro passage of primary tumor cells. However, the expression of ALDH and CD133, but not CD24, CD44 and CD117, could be partially rescued by the in vitro serum‐free and sphere cultures and by the in vivo passage in the immune‐deficient xenografts. ALDH+ and CD133+ cells formed three‐dimensional spheres more efficiently than their negative counterparts. These sphere‐forming cells expressed high levels of stem cell core gene transcripts and could be expanded and form additional spheres in long‐term culture. ALDH+, CD133+ and ALDH+CD133+ cells from fresh tumors developed larger tumors more rapidly than their negative counterparts. This property was preserved in the xenografted tumors. Altogether, the data suggest that ALDH+ and CD133+ cells are enriched with ovarian cancer‐initiating (stem) cells and that ALDH and CD133 may be widely used as reliable markers to investigate ovarian cancer stem cell biology.

Cancer mediates effector T cell dysfunction by targeting microRNAs and EZH2 via glycolysis restriction

Aerobic glycolysis regulates T cell function. However, whether and how primary cancer alters T cell glycolytic metabolism and affects tumor immunity in cancer patients remains a question. Here we found that ovarian cancers imposed glucose restriction on T cells and dampened their function via maintaining high expression of microRNAs miR-101 and miR-26a, which constrained expression of the methyltransferase EZH2. EZH2 activated the Notch pathway by suppressing Notch repressors Numb and Fbxw7 via trimethylation of histone H3 at Lys27 and, consequently, stimulated T cell polyfunctional cytokine expression and promoted their survival via Bcl-2 signaling. Moreover, small hairpin RNA–mediated knockdown of human EZH2 in T cells elicited poor antitumor immunity. EZH2+CD8+ T cells were associated with improved survival in patients. Together, these data unveil a metabolic target and mechanism of cancer immune evasion.

Total antioxidant status of peritoneal fluid in infertile women

OBJECTIVE To determine whether impairment of the antioxidant systems of peritoneal fluid might be a factor responsible for infertility. STUDY DESIGN Total antioxidant status was measured in peritoneal fluid obtained from 18 infertile women suffering from minimal or mild endometriosis, 23 patients with unexplained infertility, 12 women with tubal infertility and 13 fertile women. RESULTS Total antioxidant status was significantly lower in peritoneal fluid from women with unexplained infertility (0.49+/-0.21 mmol/l) compared to both fertile patients (0.67+/-0.24 mmol/l, P=0.02) and women with tubal infertility (0.76+/-0.26 mmol/l, P=0.001). Peritoneal fluid total antioxidant status did not differ significantly between patients with endometriosis (0.61+/-0.2 mmol/l), tubal infertility and the fertile group (P>0.05). CONCLUSIONS Our results suggest that low antioxidant status in peritoneal fluid may play a role in the pathogenesis of infertility.

Increased levels of oxidative stress markers in the peritoneal fluid of women with endometriosis

OBJECTIVE To evaluate 8-hydroxy-2-deoxyguanosine (8-OHdG) and 8-isoprostane levels in the peritoneal fluid (PF) of women with endometriosis. STUDY DESIGN One hundred and ten women with laparoscopically and histopathologically confirmed endometriosis and, as reference groups, 119 patients with simple serous (n=78) and dermoid (n=41) ovarian cysts were studied. Peritoneal fluid 8-OHdG and 8-isoprostane concentrations were evaluated by enzyme-linked immunosorbent assays. RESULTS 8-OHdG and 8-isoprostane levels in peritoneal fluid were significantly higher in patients with endometriosis compared with the reference groups. Higher PF 8-OHdG and 8-isoprostane concentrations were observed in patients with advanced stages of endometriosis. A statistically significant positive correlation was found between 8-OHdG and 8-isoprostane levels in peritoneal fluid. CONCLUSION Endometriosis induces greater oxidative stress and frequent DNA mutations in peritoneal fluid than nonendometriotic ovarian cysts. The most severe oxidative stress occurs in the peritoneal cavity of women with more advanced stages of the disease.

Tumor-Associated Macrophages and Myeloid-Derived Suppressor Cells as Immunosuppressive Mechanism in Ovarian Cancer Patients: Progress and Challenges

Cancers are complex masses of malignant cells and nonmalignant cells that create the tumor microenvironment (TME). Non-transformed cells of the TME such as tumor-associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs) have been observed in the TME of ovarian cancer (OC) patients. Although these subsets may contribute to each step of carcinogenesis and are commonly associated with poor prognosis, still little is known about creation of the protumor microenvironment in OC. In this review, we focused on the nature and prognostic significance of TAMs and MDSCs in OC patients. Moreover, we discuss the main problems and challenges that must be overcome by researchers and clinicians to enrich our knowledge about the immunosuppressive microenvironment of cancers.

Low-Density Lipoproteins Oxidation and Endometriosis

The etiopathogenesis of endometriosis still remains unknown. Recent data provide new valuable information concerning the role of oxidative stress in the pathophysiology of the disease. It has been proved that levels of different lipid peroxidation end products are increased in both peritoneal fluid (PF) and serum of endometriotic patients. We assessed the concentration of oxidized low-density lipoproteins (oxLDL) in PF of 110 women with different stages of endometriosis and 119 women with serous (n = 78) or dermoid (n = 41) ovarian cysts, as the reference groups. PF oxLDL levels were evaluated by ELISA. We found that concentrations of oxLDL in PF of endometriotic women were significantly higher compared to women with serous but not dermoid ovarian cysts. Interestingly, by analyzing concentrations of oxLDL in women with different stages of the disease, it was noted that they are significantly higher only in the subgroup of patients with stage IV endometriosis as compared to women with ovarian serous cysts. In case of minimal, mild, and moderate disease, PF oxLDL levels were similar to those noted in reference groups. Our results indicate that disrupted oxidative status in the peritoneal cavity of women with endometriosis may play a role in the pathogenesis of advanced stages of the disease.

Peritoneal Immune System in Patients with Advance Epithelial Ovarian Cancer

The development of epithelial ovarian cancer is associated with changes in the peritoneal cavity microenvironment. Tumor cells produce different factors, which impairs differentiation, maturation, and function of antigen-presenting cells. In this review, we focus on selected cell populations in the peritoneal cavity immune system and their potential role in epithelial ovarian cancer immunopathogenesis. We devote most attention to dendritic cells because they are considered to be superior in their antigen-presenting ability, compared with both macrophages and B lymphocytes. We also present a brief characterization of tumor-infiltraiting cells in epithelial ovarian cancer patients.

Investigation of glutathione concentrations in peritoneal fluid from women with and without endometriosis

UNLABELLED Changes in the peritoneal fluid (PF) environment have been implicated in the pathogenesis of endometriosis as well as in the decrease of fertility. OBJECTIVE To evaluate the concentration of glutathione in PF of women with endometriosis. PATIENTS Twenty-one patients with endometriosis (I or II rAFS stage, n=11; III or IV rAFS stage, n=10), and 29 patients with follicular or dermoid ovarian cysts (n=17 and n=12, respectively). RESULTS Mean (+/-S.D.) PF glutathione concentration was 0.22+/-0.01 micromol/ml in patients with minimal or mild endometriosis, 0.21+/-0.05 micromol/ml in women with III or IV stage of the disease, 0.24 +/- 0.03 micromol/ml in women with follicle ovarian cysts, and 0.23+/-0.05 micromol/ml in patients with dermoid tumors of ovaries. No significant difference in the peritoneal glutathione level was found between the groups. CONCLUSION These results suggest that PF glutathione is not involved in the progression of endometriosis.

Molecular bases of aberrant miR-182 expression in ovarian cancer.

The molecular bases of miR‐182 deregulation in epithelial ovarian cancers (EOCs) remain unknown and its diagnostic or prognostic role in EOCs is still unclear. We performed miR‐182 expression analysis using a microarray approach and real‐time PCR (qPCR). We also used array comparative genomic hybridization and methylated DNA immunoprecipitation to study copy number changes and methylation aberrations within coding locus/promoter sequences of miR‐182 in EOC tissues, respectively. We have found that miR‐182 expression is significantly increased in EOC (P < 0.00001) and that higher miR‐182 expression in EOC is linked with significantly shorter overall survival (P = 0.026). The methylation of miR‐182 promoter was significantly associated with lower miR‐182 expression in EOC tissues (P = 0.045). miR‐182 over‐expression is connected with copy number (CN) gains of this miRNA coding sequences in EOC (P = 0.002), and the number of PRDM5 copies is significantly and inversely correlated with miR‐182 expression evaluated by qPCR (R = −0.615, P = 0.009). We conclude that the aberrant miR‐182 expression in EOC may be due to CN gains within its coding locus. The miR‐182 promoter is rarely methylated in EOC, and its methylation status is associated with lower miR‐182 expression. Deletion of the PRDM5 locus may play a supportive role in miR‐182 overexpression in EOC. miR‐182 is an unfavorable prognostic factor in EOC.

Evaluation of risk factors can help to predict preterm delivery within 7 days in women hospitalized for threatened preterm labour

Abstract Objective: The ability to predict birth within 7 days of enrolment in women hospitalized for threatened preterm labour is essential for a proper decision to introduce corticosteroids for the treatment. Method: The study included 622 women hospitalized due threatened preterm labour. Eighteen risk factors were analysed. The predictive value for accumulation of studied risk factors was assessed using receiver operating characteristic (ROC) curve analysis and dimension-based models of assessment methods: (i) forward stepwise selection (conditional), (ii) forward stepwise selection (Wald) and (iii) backward stepwise elimination (conditional). Results: The accumulation of five and above risk factors gives specificity and positive predictive value (PPV) of diagnosis preterm delivery within 7 days of enrolment approaching 100% (99 and 98, respectively). The predictive value for studied risk factors enabled establishing the following order for risk factors significance: (i) cigarette smoking before pregnancy; (ii) low socioeconomic status; (iii) frequent contractions during pregnancy; (iv) bleeding during pregnancy; (v) urinary tract infections. Conclusion: In women hospitalized for threatened preterm labour, the accumulation of five risk factors of preterm delivery predicts preterm delivery within 7 days of enrolment. That makes easier decision to introduce corticosteroids for the treatment.