Ovarian cancer (OC) is the most lethal gynecological cancer worldwide. DNA damage plays an important role in cancer development, and the proteins encoded by XRCC1 and ERCC2 are important components of the DNA repair system. This study aimed to examine the relationship between the rs25487 XRCC1 and rs13181 ERCC2 polymorphisms and the risk of OC development in women from the Moscow region. DNA was isolated from the blood of 129 healthy donors and tissues and blood samples from 125 patients with OC and studied using real-time PCR. An increase in odds ratios (OR) was obtained for OC tissue and blood for both T (OR = 1.46, 95% confidence interval [CI] = 1.22–1.76, P = 0.00005), and for T/T of rs25487 XRCC1. The most significant OR values were found for the T/T genotype using the codominant model (OR = 2.11, 95% CI = 1.44–3.07, P = 0.00006) and dominant model (OR = 3.13, 95% CI = 1.44–6.79, P = 0.0025) for the pooled blood and tissue groups. For rs13181 ERCC2, differences were observed for the T/G genotype in OC tissues (OR = 0.69, 95% CI = 0.51–0.92, P = 0.011) in the codominant model. In this study, the association of allele T and genotypes of rs25487 XRCC1 and T/G of rs13181 ERCC2 with OC was shown. Our results indicate that these polymorphisms may be involved in the pathogenesis of OC and are promising for further studies on therapeutic applications in OC.

Background: The aim of our study was to determine the role of sphingolipids, which control proliferation and apoptosis, in the placenta of pregnant women with pregnancy-associated breast cancer (PABC) after chemotherapy compared with healthy patients. Methods: We analyzed (by the PCR method) the gene expression of key sphingolipid metabolism enzymes (sphingomyelinases (SMPD1 and SMPD3), acid ceramidase (ASAH1), ceramide synthases (CERS 1–6), sphingosine kinase1 (SPHK1), sphingosine-1-phosphate lyase 1 (SGPL1), and sphingosine-1-phosphate receptors (S1PR1, S1PR2, and S1PR3)) and the content of subspecies of ceramides, sphingosine, and sphingosine-1-phosphate in seven patients with PABC after chemotherapy and eight healthy pregnant women as a control group. Results: We found a significant increase in the expression of genes of acid ceramidase (ASAH1), sphingosine-1-phosphate lyase 1 (SGPL1), sphingosine kinase (SPHK1), and ceramide synthases (CERS 1-3, 5, 6) in the samples of patients with PABC during their treatment with cytostatic chemotherapy. The increase in the expression of the enzymes’ genes was not accompanied by changes in the content of the studied sphingolipids. Such significant changes in the expression of genes controlling the level of CER, sphingosine, and S1P may indicate their ability to initiate the metabolism of pro-apoptotic and anti-apoptotic sphingolipids in the placenta of pregnant women with cancer undergoing chemotherapy in order to maintain levels typical of the placenta of healthy women. Conclusions: Our results may indicate the promising mechanism of placenta protection during chemotherapy for pregnant women with breast cancer and, consequently, of the newborn. This protective effect of the placenta and especially for the newborn has been discovered for the first time and requires more careful study.

Background. Breast cancer is the most common cancer among women. Triple negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, in which there are no special targets for therapy. Therefore chemotherapy is still leading treatment for TNBC including the regiments with platinum drugs.Aim. To study the association of polymorphic markers of the genes XRCC1 (rs25487), ERCC5 (rs17655), TP53 (rs1042522), CDKN1A1 (rs1801270) with progression-free survival (PFS) and overall survival (OS) of TNBC patients after platinum-based neoadjuvant chemotherapy.Materials and methods. Polymorphic markers of the XRCC1, ERCC5, CDKN1A and TP53 genes were studied in blood samples of 67 patients with stage II–III TNBC by real-time polymerase chain reaction with fluorescent allele-specific probes. The results of determining the markers were compared with PFS and OS using the Kaplan–Meyer method and the log-rank-test.Results. The association was found for the polymorphic marker rs25487 of the XRCC1 gene with PFS (carrying the T/T genotype was associated with a decrease of median PFS: 15.6 months versus 34.3 months, p = 0.013) and OS (carrying the T allele was associated with a decrease of median OS: 24.3 months versus 34.6 months, p = 0.041) without depending on the BRCA status. For the polymorphic marker rs17655 of the ERCC5 gene, significant difference in PFS was obtained in the period from 15.4 to 60.0 months of follow-up (the carrier of the C allele was associated with a decrease of median PFS: 20.0 months versus 35.2 months, p = 0.035). When considering the genotypes of the polymorphic marker of the ERCC5 gene differences were revealed between patients with the C/C genotype (M = 15.9 months) and two other genotypes (M = 33.6 months), p = 0.039. For the polymorphic marker rs1801270 of the CDKN1A gene significant differences in PFS were obtained in the period from 15.4 to 60.0 months of follow-up (for carriers of allele A, a decrease in median PFS was observed: 16.6 months versus 32.0 months, p = 0.046). For the polymorphic marker of the TP53 gene (rs1042522) a tendency to decrease OS for carriers of the C/C genotype was found seems promising for further study.Conclusion. The association of the studied polymorphic markers of the genes XRCC1 (rs25487), ERCC5 (rs17655) and CDKN1A (rs1801270) with PFS was revealed in patients with TNBC. Association with OS was obtained for the polymorphic marker of the XRCC1 gene (rs25487). These data may allow for further validation to individualize the treatment of this category of patients.

Цель. Изучение связи полиморфных маркеров генов репарации ДНК ERCC2 (rs13181), ERCC5 (rs17655), транспортного белка ABCB1 (rs1045642, rs2032582) с клиническим ответом и степенью патоморфологической регрессии (ПР) опухоли у беременных женщин с онкологическими заболеваниями после ХТ препаратами платины.