Stefan Sajdak

Vitamin D Receptor Gene BsmI and FokI Polymorphisms in Relation to Ovarian Cancer Risk in the Polish Population

BACKGROUND The role of vitamin D receptor (VDR) single-nucleotide polymorphisms (SNPs) in ovarian cancer has been studied in various populations; however, these results are discordant between different ethnicities. METHOD Using the polymerase chain reaction-restriction fragment length polymorphism method, we studied the prevalence of the VDR FokI (rs2228570) and BsmI (rs1544410) SNPs in women with ovarian cancer (n=168) and controls (n=182) in a Polish population. RESULTS We found a significant contribution of the BsmI SNP Bb+BB-versus-bb dominant inheritance model to ovarian cancer development (p=0.0221, p(corr)=0.0442, odds ratio [OR]=1.648 [95% confidence intervals, CI=1.073-2.532]). However, we did not observe an association of the BsmI SNP BB versus Bb+bb recessive inheritance model in patients (p=0.8059, OR=1.093 [95% CI=0.538-2.218]). Moreover, there was no association of FokI SNPs either in Ff+ff versus FF dominant or ff versus Ff+FF recessive inheritance models with ovarian cancer development (p=0.9924, OR=1.002 [95% CI=0.628-1.599] and p=0.1123, OR=1.542 [95% CI=0.901-2.638], respectively). The p-values of the trend test observed for the VDR BsmI and FokI SNPs in patients with ovarian cancer were p(trend)=0.0613 and p(trend)=0.3655, respectively. CONCLUSION Our study indicates that the VDR B gene variant might be a moderate risk factor of ovarian cancer development in the Polish population.

Does Metformin affect ER, PR, IGF-1R, β-catenin and PAX-2 expression in women with diabetes mellitus and endometrial cancer?

ObjectiveDiabetes mellitus, as a risk factor for endometrial cancer (EC), causes an increase in insulin and IGF-1 concentrations in the blood serum. The increase in insulin and IGF-1 are considered mitogenic factors contributory to cancer development. Studies suggest that metformin has preventive activity, decreasing mortality and the risk of neoplasms. Since estrogen (ER), progesterone (PR) and IGF-1 (IGF-1R) receptor expression and β-catenin and PAX-2 mutations are significant in the development of endometrial cancer, it was decided to study these factors in patients with endometrial cancer and type 2 diabetes mellitus (DM2), and to establish the effects of metformin on their expression.MethodsThe expression of ER, PR, IGF-1R, β-catenin and PAX-2 have been immunohistochemically investigated in 86 type I endometrial cancer specimens. Patients were grouped according to the presence of DM2 and the type of hypoglycemic treatment administered.ResultsComparing EC patients with DM2 and normal glycemic status, we found increased IGF-1R expression in women with DM2. A decrease in ER expression was noted in women with EC and DM2 receiving metformin as compared to women treated with insulin (p = 0.004). There was no statistically significant difference in PR, IGF-1R, β-catenin and PAX-2 expression among women receiving metformin and other hypoglycemic treatment.ConclusionAlthough epidemiological studies suggest the beneficial role of metformin in many human cancers, there are still few studies confirming its favorable effect on endometrial cancer. Decreased ER expression in patients receiving metformin needs further research to allow evaluation of its clinical significance.

Role of osteopontin in differential diagnosis of ovarian tumors

The aim of this study was to evaluate the role of the serum osteopontin (OPN) level as a biomarker for discriminating between malignant and benign ovarian tumors. Furthermore, comparisons with the diagnostic usefulness of the other tests were performed.

Ovarian cancer-derived ascitic fluids induce a senescence-dependent pro-cancerogenic phenotype in normal peritoneal mesothelial cells

PurposeAfter the seeding ovarian cancer cells into the peritoneal cavity, ascitic fluid creates a microenvironment in which these cells can survive and disseminate. The exact nature of the interactions between malignant ascitic fluids and peritoneal mesothelial cells (HPMCs) in ovarian cancer progression has so far remained elusive. Here we assessed whether malignant ascitic fluids may promote the senescence of HPMCs and, by doing so, enhance the acquisition of their pro-cancerogenic phenotype.MethodsPrimary omentum-derived HPMCs, ovarian cancer-derived cell lines (A2780, OVCAR-3, SKOV-3), malignant ascitic fluids and benign ascitic fluids from non-cancerous patients were used in this study. Ovarian cancer cell proliferation, as well as HPMC proliferation and senescence, were determined using flow cytometry and β-galactosidase assays, respectively. Ovarian cancer cell migration was quantified using a Transwell assay. The concentrations of soluble agents in ascitic fluids, conditioned media and cell lysates were measured using DuoSet® Immunoassay Development kits.ResultsWe found that HPMCs, when exposed to malignant ascitic fluids, exhibited decreased proliferation and increased senescence rates. The malignant ascitic fluids were found to contain elevated levels of HGF, TGF-β1 and GRO-1, of which HGF and GRO-1 were able to induce senescence in HPMCs. We also found that HPMCs subjected to malignant ascitic fluids or exogenously added HGF and GRO-1 stimulated ovarian cancer cell progression, which was manifested by an increased production of HA (adhesion), uPA (proliferation), IL-8 and MCP-1 (migration).ConclusionOur results indicate that malignant ascitic fluids may contribute to ovarian cancer progression by accelerating the senescence of HPMCs.

External validation of the IOTA ADNEX model performed by two independent gynecologic centers

OBJECTIVES The external, two-center validation of the IOTA ADNEX model for differential diagnosis of adnexal tumors. METHODS A total of 204 patients with adnexal masses (134 benign and 70 malignant) treated at the Division of Gynecologic Surgery, Poznan University of Medical Sciences, Poland (Center I), and 123 patients (89 benign and 34 malignant) from the Department of Obstetrics and Gynecology, Clinica Universidad de Navarra, University of Navarra School of Medicine, Pamplona, Spain (Center II), were enrolled into the study. RESULTS ADNEX achieved high accuracy in discriminating between malignant and benign ovarian tumors in both centers (79.9% and 81.3% in Centers I and II, respectively). Multiclass accuracy was substantially lower than in binary classification (malignant vs. benign): 64.2% and 74.0% in Centers I and II, respectively. Sensitivity and specificity for the diagnosis of specific tumor types in Center I were as follows: benign tumors - 72.4% and 94.3%; borderline tumors - 33.3% and 87.0%, stage I ovarian cancers - 00.0% and 91.8%; stage II-IV ovarian cancers - 68.2% and 83.1%; and metastatic tumors - 00.0% and 99.5%. Sensitivity and specificity in Center II were as follows: benign tumors - 75.3% and 97.1%; borderline tumors - 50.0% and 88.2%, stage I ovarian cancers - 40.0% and 97.5%; stage II-IV ovarian cancers - 95.0% and 88.3%; and metastatic tumors - 20.0% and 98.3%. CONCLUSIONS ADNEX is characterized by very high accuracy in differentiating between malignant and benign adnexal tumors. However, prediction of ovarian tumor types could be more accurate.

Senescent peritoneal mesothelium creates a niche for ovarian cancer metastases

Although both incidence and aggressiveness of ovarian malignancy rise with age, the exact reason for this tendency, in particular the contribution of senescent cells, remains elusive. In this project we found that the patient’s age determines the frequency of intraperitoneal metastases of ovarian cancer. Moreover, we documented that senescent human peritoneal mesothelial cells (HPMCs) stimulate proliferation, migration and invasion of ovarian cancer cells in vitro, and that this effect is related to both the activity of soluble agents released to the environment by these cells and direct cell-cell contact. The panel of mediators of the pro-cancerous activity of senescent HPMCs appeared to be cancer cell line-specific. The growth of tumors in a mouse peritoneal cavity was intensified when the cancer cells were co-injected together with senescent HPMCs. This effect was reversible when the senescence of HPMCs was slowed down by the neutralization of p38 MAPK. The analysis of lesions excised from the peritoneum of patients with ovarian cancer showed the abundance of senescent HPMCs in close proximity to the cancerous tissue. Collectively, our findings indicate that senescent HPMCs which accumulate in the peritoneum in vivo may create a metastatic niche facilitating intraperitoneal expansion of ovarian malignancy.

Extracellular matrix metalloproteinase inducer (EMMPRIN) expression correlates positively with active angiogenesis and negatively with basic fibroblast growth factor expression in epithelial ovarian cancer

PurposeThe primary aim of this paper was to evaluate the expression of extracellular matrix metalloproteinase inducer (EMMPRIN) and its relationship with proangiogenic factors and microvessel density (MVD) in ovarian cancer.MethodsThe study group included 58 epithelial ovarian cancers (EOCs), 35 benign ovarian tumors, and 21 normal ovaries. The expression of EMMPRIN, vascular endothelial growth factor (VEGF), and basic fibroblast growth factor (bFGF) was assessed by ELISA of tissue homogenates. Antibodies against CD105, CD31, and CD34 were used to immunohistochemically assess MVD.ResultsWe have found significantly higher EMMPRIN expression in EOC than in benign ovarian tumors and normal ovaries. Similarly, the VEGF expression was higher in EOC than in benign ovarian tumors and normal ovaries. By contrast, bFGF expression was lower in EOC than in benign ovarian tumors and ovary samples. EMMPRIN expression in EOC was directly correlated with VEGF expression and CD105-MVD, but inversely correlated with bFGF expression. Grade 2/3 ovarian cancers had increased expression of EMMPRIN and VEGF, increased CD105-MVD, and lowered expression of bFGF compared to grade 1 ovarian cancers. Moreover, EMMPRIN expression was higher in advanced (FIGO III and IV) ovarian cancer.ConclusionsThe upregulation of EMMPRIN and VEGF expression is correlated with increased CD105-MVD and silenced bFGF, which suggests early and/or reactivated angiogenesis in ovarian cancer. Aggressive EOC is characterized by the following: high expression of EMMPRIN and VEGF, high CD105-MVD, and low expression of bFGF.

Angiogenesis and cancer stem cells: New perspectives on therapy of ovarian cancer

Failure in ovarian cancer therapy, following cytoreduction and chemotherapy, is related to the presence of cancer stem cells - a small subpopulation of cells resistant to chemotherapy and irradiation - in the tumour which may cause cancer relapse and manifestation of metastases. Therapies targeted at Cancer Stem Cells (CSCs), such as those employing metformin (a drug used in the treatment of diabetes type II) and salinomycin, an antibiotic isolated from Streptococcus albus bacteria, seem promising. Anti-angiogenic therapy with bevacizumab was found to be effective in all phases of ovarian cancer treatment. The presence of CSCs has been associated with angiogenesis. Several CSC biomarkers correlate with the markers of angiogenesis and some signalling pathways, e.g. Notch, and are used by both CSCs and by pro-angiogenic factors.

Biochemical composition of malignant ascites determines high aggressiveness of undifferentiated ovarian tumors

Although undifferentiated tumors are the most lethal among all ovarian cancer histotypes, the exact reasons for this situation are unclear. This report was aimed at investigating whether the high aggressiveness of undifferentiated ovarian cancer may be associated with a biochemical composition of malignant ascites accumulating in the peritoneal cavity. We analyzed ascites from patients with undifferentiated, high-grade serous, endometrioid and clear-cell ovarian cancers, and from non-cancerous patients with respect to a group of soluble agents involved in cancer cell progression. Moreover, the effect of these fluids on proliferation and migration of ovarian cancer cells (A2780, OVCAR-3 and SKOV-3) was evaluated. The study showed that the level of all tested proteins in malignant ascites was higher than in the benign fluids. Concentration of 9/11 agents (CCL2, CXCL1, CXCL5, CXCL8, CXCL12, HGF, PAI-1, TGF-β1 and VEGF) was the greatest in the fluids from undifferentiated cancer, while the level of remaining 2 (IL-6 and uPA) was the highest in ascites from serous carcinoma. Proliferation of cancer cells was the most effective when they were subjected to ascites from patients with undifferentiated and serous cancer, whereas the migration was the highest in the case of undifferentiated tumors. Our findings indicate that the aggressiveness of undifferentiated ovarian tumors may be associated with the composition of malignant ascites, in particular the concentration of specific proinflammatory, cancer-promoting agents.

Serum arylesterase and paraoxonase activities in patients with ovarian tumors

OBJECTIVE High levels of toxic reactive oxygen species have been found in many types of cancer cells. Serum arylesterase (ARE) and paraoxonase (PON) are esterase enzymes that have strong antioxidant characteristics. The main purpose of our study was to evaluate the activity of ARE and PON in the sera of patients with ovarian cancer and benign ovarian tumors. MATERIALS AND METHODS This study included 30 patients with ovarian cancer, 42 patients with benign ovarian tumors, and 19 healthy age- and sex-matched individuals. ARE and PON activities were measured using spectrophotometry. RESULTS Serum ARE activity was significantly different among the three studied groups (p<0.0001). However, posthoc tests revealed that ARE activity was lower in the benign ovarian tumor group (median, 1.53 U/mL; range, 0.43-2.47 U/mL) than in the other groups. There were no differences in ARE activity between patients with ovarian cancer (1.89 U/mL; range, 1.01-2.56 U/mL) and healthy individuals (2.05 U/mL; range, 0.79-2.44 U/mL). We found no differences in PON activity or the PON:ARE activity ratio between the studied groups. Tumor size in the benign ovarian tumor group was positively correlated with ARE activity (R Spearman=0.46, p=0.003) and negatively correlated with PON activity (R Spearman=-0.50, p=0.001). The ARE and PON activities were not influenced by histological type, ovarian cancer grade, or disease advancement. CONCLUSION ARE activity is higher in patients with ovarian cancer than in patients with benign ovarian tumors; however, the serum activity of ARE is similar between patients with cancer and healthy individuals.