Soluble forms of immune checkpoints in ovarian cancer.

The data of a complex immunoassay comparative study of the content of soluble forms of sPD-1, sPD-L1, sNKG2D, sNKG2DL1, sB7-H3 and sHLA-G in the blood plasma of 75 patients with epithelial ovarian cancer and 20 healthy donors of the control group are presented. The diagnostic significance of the studied proteins was determined. The study showed that the profile of soluble immunity checkpoints differs when malignant ovarian pathology occurs. There was a statistically significant decrease in the content of sPD-L1, sNKG2DL1, sB7-H3, and sHLA-G in the blood plasma of patients compared with the control group. Differences were found in the content of the studied markers depending on the histological type of tumors. Correlations between the soluble forms of some of the studied proteins are shown, indicating the presence of independent mechanisms of immune regulation in ovarian cancer, which may explain the insufficient effectiveness of the existing immunotherapy for this type of tumor. The results obtained will undoubtedly facilitate the development of new effective methods for the diagnostics and therapy of ovarian cancer.

[Clinical significance of methylation of a group of miRNA genes in patients with ovarian cancer.]

It was found that the proportion of microRNA genes inactivated by methylation of regulatory CpG islands is several times higher than the genes encoding proteins, which increases their attractiveness as promising markers of cancer. The aim of this work is to evaluate the clinical significance of methylation of 13 tumor-associated microRNA genes (MIR-124a-2, MIR-124a-3, MIR-125-B1, MIR-127, MIR-129-2, MIR-132, MIR-137, MIR-203a, MIR-34b/c, MIR-375, MIR-9-1, MIR-9-3, MIR-339) in 26 patients with ovarian cancer. Methylation level was evaluated by the method of methylation-specific PCR in real time. The data obtained in primary tumors (26), histologically unchanged ovarian tissues (15) and peritoneal metastases (19) were compared using a number of statistical programs. For all 13 genes, an increase in the level of methylation was revealed during the transition from unchanged tissue to primary tumors and further from primary tumors to peritoneal metastases; moreover, in the genes MIR-203a, MIR-375 and MIR-339, the level of methylation in metastases increased most significantly (in 2 and more times). A correlation was observed for the first time, showing a consistency between the increase in methylation level in some miRNA pairs, for example, MIR-129-2/MIR-132 (rs> 0,7; p<0,0001), both in primary tumors and in metastases. An analysis of microRNA gene methylation in clinical samples of ovarian cancer showed a correlation between the observed molecular changes both with the initial stages of tumor formation and with the progression and dissemination of ovarian cancer, with the presence of metastases in a large omentum and with the appearance of ascites. The revealed dependencies deepen the understanding of the mechanism of peritoneal metastasis and can be used to select new diagnostic and prognostic markers of ovarian cancer.

[Hypermethylation of miR-107, miR-130b, miR-203a, miR-1258 Genes Associated with Ovarian Cancer Development and Metastasis].

It is known that microRNAs (miRNAs) are able to dynamically regulate gene expression. At the same time, methylation can reduce expression of miRNA encoding genes and, therefore, reduce their inhibitory effects on mRNAs of target genes, including those of oncogenes, that promoting the development of tumors of different localization. The role of miRNA hypermethylation in the pathogenesis of ovarian cancer is not completely understood; so we conducted a search for new hypermethylated and potentially suppressor miRNA genes in ovarian tumors. Four new miRNA genes (MIR-107, MIR-130b, MIR-203a, MIR-1258) commonly hypermethylated (28-52%) in tumor tissues vs 4-7% in paired histologically normal tissues, p < 0.01, were identified in a representative set of 54 ovarian cancer samples using methylation-specific PCR. It was shown that hypermethylation of MIR-130b, MIR-203a, and MIR-1258 genes is significantly (p < 0.05) associated with metastasis of ovarian cancer. These results suggest the involvement of four miRNAs (miR-107, miR-130b, miR-203a, and miR-1258) and hypermethylation of their encoding genes in the pathogenesis of ovarian cancer.

Insulin-Like Growth Factors (IGF) and IGF-Binding Proteins (IGFBP) in the Serum of Patients with Ovarian Tumors.

IGF-1, IGF-2, and IGFBP-1,2,3 were assayed in blood serum of patients with malignant ovarian tumors (n=44), borderline ovarian tumors (n=11), and benign ovarian tumors (n=12) as well as in healthy women (n=33). In blood serum of patients with malignant ovarian tumors, the level of IGF-1 was lower and IGFBP-1 was higher than in other groups. In patients with malignant and borderline ovarian tumors, the level of IGFBP-2 was higher than in healthy women and in patients with benign ovarian tumors. There was no correlation between most examined parameters and the clinical and morphological peculiarities of ovarian tumors. The study revealed IGF/IGFBP imbalance in patients with malignant ovarian tumor and showed that IGFBP-2 proved to be a potential diagnostic serological marker w with 90% sensitivity and 90% specificity.

Relationship between the expression of VEGF signal components and matrix metalloproteinases in ovarian tumors.

The content of vascular endothelium growth factor is significantly increased, while the level of matrix metalloproteinase-2 is 2-fold reduced in ovarian cancer tissue compared to benign tumors. A trend to an increase in the levels of matrix metalloproteinases 7 and 9 and reduction of vascular endothelial growth factor type 2 receptors in tumor tissue was also detected. A highly significant negative correlation between the levels of vascular endothelial growth factor and matrix metalloproteinase 2 and positive correlations between vascular endothelial growth factor and matrix metalloproteinase 7, vascular endothelial growth factor and matrix metalloproteinase 9, matrix metalloproteinase 2 and vascular endothelial growth factor type 2 receptors were revealed. In the tumors assayed after preoperative therapy, relative normalization of the studied parameters was observed: the level of vascular endothelial growth factor decreased significantly, while the levels of matrix metalloproteinase 2 and vascular endothelial growth factor type 2 receptors increased. The levels of the markers differed significantly in ovarian tumors of different histological types, and the levels of vascular endothelial growth factor type 2 receptors were higher in patients with stage III compared to stage I and the content of matrix metalloproteinase 7 was higher in stage III compared to stage II cancer.