[Circumscribed choroidal hemangioma and non-pigmented choroidal melanoma: clinical, instrumental and molecular genetic features]. / Otgranichennaya gemangioma i bespigmentnaya melanoma khorioidei: kliniko-instrumental'nye i molekulyarno-geneticheskie osobennosti.

Circumscribed choroidal hemangioma (CCH) and early non-pigmented choroidal melanoma (CM) have similar clinical, ultrasound and morphometric features, which in some cases makes their differential diagnosis difficult. There are few studies in the literature devoted to a comparative analysis of the molecular genetic features of CCH and non-pigmented CM, and the results of those studies are contradictory. PURPOSE: This study attempts to develop a method of non-invasive molecular genetic differential diagnostics of CCH and non-pigmented CM. MATERIAL AND METHODS: Based on the results of clinical and instrumental examination methods, 60 patients (60 eyes) with CCH (n=30) and non-pigmented CM (n=30) were included in this prospective study. The control group consisted of 30 individuals without intraocular tumors. Mutations in the GNAQ/GNA11 genes were determined by real-time PCR using the analysis of genomic circulating tumor DNA isolated from peripheral blood plasma. The average follow-up period was 12.1±1.8 months. RESULTS: The study revealed a significant association of mutations in exons 4 and 5 of the GNAQ/GNA11 genes with the presence of non-pigmented CM (27/30; 90%). These mutations were not detected in the group of patients with CCH. Mutations in exons 4 and 5 of the GNAQ/GNA11 genes were also not detected in the control group of healthy individuals. CONCLUSION: This study proposes a method of non-invasive and low-cost differential diagnostics based on molecular genetic analysis and detection of mutations in exons 4 and 5 of the GNAQ and GNA11 genes, which are specific for CM (90%).

DNA Methylation of a Group of Long Non-Coding RNA Genes at Different Stages of Ovarian Cancer Dissemination.

There are three types of metastases in ovarian cancer: lymphogenous, hematogenous, and peritoneal. Dissemination of the tumor in the peritoneum is directly related with the development of ascites and a poor prognosis. The purpose of this study is to determine changes in the methylation level of a group of long non-coding RNA (lncRNA) genes at different stages of ovarian cancer progression. The methylation level of 7 lncRNA genes (LINC00472, LINC00886, MAFG-DT, SNHG1, SNHG6, TP53TG1, and TUG1) was studied by quantitative methyl-specific PCR in 93 samples of ovarian tumors and 75 paired samples of histologically normal tissue, as well as in 29 peritoneal macroscopic metastases. Using the nonparametric Mann-Whitney test, a significant (p<0.001) increase in the level of methylation of the LINC00886, SNHG1, SNHG6, and TUG1 genes in the tumor tissue was shown. For the LINC00472, LINC00886, and SNHG6 genes, a significant relationship was found with the clinical stage (p≤0.001), as well as with the appearance of metastases for the LINC00472 (p<0.001) and SNHG6 (p=0.005) genes. There was a significant increase in the level of methylation of MAFG-DT and TP53TG1 (p<0.001) genes, as well as a decrease in LINC00886 (p=0.003) in peritoneal metastases relative to the primary focus. Methylation of the LINC00472 and SNHG6 genes can be considered as a factor in initiating ovarian cancer metastasis, and methylation of the LINC00886, MAFG-DT, and TP53TG1 genes as a colonization factor for metastases in the peritoneum. Thus, a relationship between methylation of a group of lncRNA genes at different stages of ovarian cancer dissemination was shown, which is important for understanding the mechanisms of these processes and for developing innovative approaches to ovarian cancer therapy.

The Role of Methylation of a Group of microRNA Genes in the Pathogenesis of Metastatic Renal Cell Carcinoma.

The role of methylation of 9 miRNA genes in the pathogenesis of metastatic clear cell renal cell carcinoma was determined by quantitative methylation-specific PCR (MS-PCR). For 5 genes (MIR125B-1, MIR137, MIR193A, MIR34B/C, and MIR375), a significant correlation of high methylation level with late (III-IV) stages, large size (T3+T4) of the tumor, and metastasis to lymph nodes and/or distant organs was revealed. For another group of genes (MIR125B-1, MIR1258, MIR193A, MIR34B/C, and MIR375), a statistically significant correlation of high methylation level with loss of differentiation in the tumor (G3-G4) was found, and the opposite pattern was found for MIR203A. A total of 7 microRNA genes (MIR125B-1, MIR1258, MIR137, MIR193A, MIR203A, MIR34B/C, and MIR375) were identified, the methylation of which is associated with the progression of metastatic clear cell renal cell carcinoma. For 6 of them (except MIR34B/C) these data were obtained for the first time. Thus, new factors of the development and progression of clear cell renal cell carcinoma were identified as potential biomarkers for the early diagnosis and prognosis of metastatic clear cell renal cell carcinoma.

Long Non-Coding RNAs and microRNAs Groups in the Regulation of Expression Level of a Number of Tumor-Associated Genes in Ovarian Cancer.

The search for interacting long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and mRNAs of protein-coding genes through the mechanism of competing endogenous RNAs in tumors of ovarian cancer patients was carried out. The levels of expression of 24 lncRNAs, 20 miRNAs, and 28 mRNAs of protein-coding genes involved in oncogenesis were determined by real-time PCR on a set of representative samples. Correlations between lncRNAs/miRNA and miRNA/mRNA levels in ovarian cancer samples were analyzed. We identified 8 pairs of lncRNAs/miRNA and 17 pairs of miRNA/mRNA, the expression levels of which have a negative correlation. Five triplets of potentially interacting lncRNAs/miRNA/mRNA have been identified, among which the most significant triplet is the OIP5-AS1/miR-203a-3p/ZEB1. The data obtained determine new epigenetic profiles, as well as new potential biomarkers and targets for targeted therapy of ovarian cancer patients.

[Predictive significance of genetic analysis of the development of dry eye disease of different origin]. / Prediktivnaya znachimost' geneticheskogo analiza razvitiya sindroma «sukhogo glaza¼ razlichnogo geneza.

One of the etiological causes of dry eye disease (DED) is systemic autoimmune diseases (AID): primary Sjögren's syndrome (PSS), rheumatoid arthritis (RA); their manifestation may begin with ophthalmic symptoms. The relationship of PSS and RA with genetic factors is proven. The contribution of polymorphic markers of the genes THBS1, MUC1, TRIM21, STAT4, PTPN22 in the development of these diseases is established, as well as their connection with the development of DED. A panel of genetic markers for evaluating the risk of developing DED in PSS and RA is developed, and its sensitivity and specificity is determined. PURPOSE: The aim of the study was to determine the prognostic significance of a panel of polymorphic gene markers in the development of dry eye syndrome in patients with primary Sjögren's syndrome and rheumatoid arthritis over a five-year follow-up period. MATERIAL AND METHODS: Patients with a verified diagnosis of PSS and RA without signs of DED were examined (n=35 and n=42, respectively). The control group included 82 volunteers without AID and DED. The observation period was 5 years. Every year all study subjects underwent an ophthalmological clinical and functional examination. RESULTS: Dry eye disease had developed in groups of patients with AID with predisposing genotypes of polymorphic markers of the genes THBS1, MUC1, TRIM21, STAT4, PTPN22. The peak of DED development in these patients was in the third year of the follow-up. As a result of ROC analysis, it was found that the sensitivity and specificity of determining the predisposing genotypes of polymorphic markers of the THBS1, MUC1, TRIM21, STAT4, PTPN22 genes was 68 and 87%, respectively (p<0.0001). CONCLUSION: Genetic research methods are essential for minimally invasive early diagnosis of dry eye disease, and can subsequently become the basis for a personalized approach to its treatment.

Hypermethylation of Long Non-Coding RNA Genes Group in the Breast Cancer Development and Progression.

We analyzed changes in the level of methylation of CpG islands in four long non-coding RNA (lncRNA) genes MEG3, ZNF667-AS1, GAS5, and SEMA3B-AS1 as promising markers of breast cancer. Methylation analysis was performed by quantitative methylation-specific PCR on a set of 38 paired (tumor/normal) breast cancer samples. Significantly (p<0.001) increased methylation was shown for three of the four lncRNA genes: MEG3, ZNF667-AS1, and SEMA3B-AS1. We found significant correlations of the methylation level of all the studied lncRNA genes with the stage of cancer and with lymphogenic metastasis, and for MEG3 and ZNF667-AS1 also with the tumor size. Methylation of ZNF667-AS1, and SEMA3B-AS1 genes in breast cancer was detected for the first time. Based on these findings, new potential markers for the diagnosis and prognosis of breast cancer can be proposed.

Synergy between the Levels of Methylation of microRNA Gene Sets in Primary Tumors and Metastases of Ovarian Cancer Patients.

We studied the correlations between the levels of methylation of a group of 21 microRNA genes in 99 primary tumors and 29 macroscopic peritoneal metastases of ovarian cancer. Analysis of the level of methylation by quantitative methylation-specific PCR showed that co-methylation was detected for 13 pairs of microRNA genes in primary tumors and for 22 pairs in metastases. Pairs of microRNA genes that have shown significant co-methylation can be involved in common processes and pathways of gene regulation and interaction and can have common target genes. The results are highly significant and pairs of microRNA genes can be proposed as new potential markers for the diagnosis and prognosis of ovarian cancer metastasis.

[The role of molecular genetic factors in the development of cholangiocellular carcinoma]. / Rol' molekulyarno-geneticheskikh faktorov v razvitii kholangiotsellyulyarnogo raka.

The article lists the main inducers of cholangiocarcinogenesis. The main inflammatory mediators (IL-6, nitric oxide, COX2) have been considered. Data on the study of gene mutations in cholangiocarcinomas are presented. The spectrum of genetic mutations depends on the biliary cancer origin (FGFR2 with intrahepatic cholangiocarcinoma, PRKACA, PRKACB with extrahepatic cholangiocarcinoma). Mutations in the KRAS, TP53, ARIAD1A genes are common in extrahepatic bile duct cancer. The role of epigenetic changes such as DNA hypermethylation, histone modifications, chromatin remodeling, as well as disturbances in miRNA expression is presented. A number of epigenetic features, such as the presence of a TP53 mutations with hypermethylation of p14ARF, DAPK, and/or ASC, correlate with a more aggressive course of the disease. The role of the SOX17 gene in the development of drug resistance is highlighted. The study of the molecular genetic features of extrahepatic bile duct cancer can help to better understand the pathogenesis of this type of tumor, to establish new prognostic and diagnostic markers of the disease.

The Role of Long Non-Coding RNA CCAT1 and SNHG14 in Activation of Some Protein-Coding Genes Associated with the Development of Ovarian Cancer.

Late diagnosis of ovarian cancer is one of the most important problems in its treatment. Long non-coding RNA (lncRNA) are a poorly studied, but promising type of diagnostic biomarkers. We studied the lncRNA interactome to identify biomarkers with potential significance for molecular diagnostics of ovarian cancer. By screening the TCGA database, we identified differentially expressed lncRNA CCAT1 and SNHG14. Based on the indices of complementarity of CCAT1 and SNHG14 to the mRNA sequences, we selected 5 protein-coding genes MAPK1, c-MET, TGFB2, SNAIL1, and WNT4 associated with the epithelial-mesenchymal transition. Real-time PCR on 54 ovarian cancer samples confirmed the high expression levels of CCAT1 and SNHG14 (logFC>1.5, p<0.05). A positive correlation between the expression levels of two lncRNA and mRNA of 5 genes in 6 pairs was established. The activating effect of CCAT1 and SNHG14 on the expression of these genes can be mediated by miR-203 and miR-124.

Changes in the Level of Methylation of a Group of microRNA Genes as a Factor in the Development and Progression of Non-Small Cell Lung Cancer.

We studied changes in the level of methylation of a number of microRNA genes hypermethylated in non-small cell lung cancer and its histological subtypes as well as the relationship of methylation of a group of microRNA genes with clinical and morphological features of the tumor with smoking status. A significantly high level of methylation of 7 genes (MIR124-1/3, MIR125B-1, MIR129-2, MIR137, MIR1258, and MIR339) was revealed in adenocarcinoma and squamous cell lung cancer in comparison with samples of adjacent histologically unchanged lung tissue. In squamous cell lung cancer, a significantly high level of methylation of the MIR124-2 gene in the tumor was also shown. In addition, differences in the methylation profile of adenocarcinoma and squamous cell carcinoma at stages III-IV of the oncological process were revealed. A high level of methylation of the MIR137 and MIR1258 genes was shown for adenocarcinoma and MIR339, MIR129-2, and MIR124-2 for squamous cell carcinoma. Significant differences in the level of methylation of MIR124-2 and MIR375 genes were revealed for smoking patients with squamous cell lung cancer.

Optimized Marker System for Early Diagnosis of Breast Cancer.

Changes in the methylation levels of 21 microRNA genes in 91 breast cancer samples in comparison with paired samples of histologically unchanged tissue were studied by quantitative methylation-specific PCR. For 19 microRNA genes, a significant increase in the methylation level in tumors in comparison with normal tissues was shown (Mann-Whitney test). When considering the data for breast cancer samples only from patients with clinical stages I and II (59samples), 17 genes with a significantly increased level of methylation were identified. Increased methylation level for 11 genes (MIR124-1, MIR124-3, MIR125B-1, MIR127, MIR129-2, MIR132, MIR137, MIR193a, MIR34B/C, MIR375, and MIR9-1) compared to the paired norm was highly significant (p<0.001, FDR=0.01). The ROC analysis was used to optimize a set of markers for diagnosing breast cancer at the early stages consisting of 4 microRNA genes: MIR125B1, MIR127, MIR1258, and MIR132; the system is characterized by 100% specificity, 85% sensitivity, and AUC=0.924. Importantly, 100% specificity eliminates false positive results. Detection of methylation of at least one of the 4 genes of this set is sufficient to classify the patient's sample as breast cancer.

Aberrant Methylation of 21 MicroRNA Genes in Breast Cancer: Sets of Genes Associated with Progression and a System of Markers for Predicting Metastasis.

Systemic analysis of the relationship between the levels of methylation of 21 microRNA genes and the parameters of breast cancer progression was performed on a representative sample of 91 paired specimens of breast cancer and histologically normal tissues and a system of markers for prediction of metastasis was proposed. A significant association of hypermethylation of 11 genes with late (III-IV) clinical stages was found, and for 6 genes (MIR124-1, MIR127, MIR34B/C, MIR9-3, MIR1258, and MIR339) this association was highly significant (p≤0.001, FDR=0.01). For MIR9-3 and MIR339, an association with tumor size was demonstrated (p<0.001, FDR=0.01). No association of the levels of methylation of the analyzed microRNA genes with the degree of differentiation were found. An association with lymph node metastasis was established for 9 microRNA genes; the most significant association was shown for 6 genes MIR125B-1, MIR127, MIR9-3, MIR339, MIR124-3, and MIR1258 (p<0.005, FDR=0.05). Based on these 6 genes, a marker system for predicting breast cancer metastasis was developed by ROC analysis. This system is characterized by 87% sensitivity and 77% specificity (AUC=0.894). The proposed system may have clinical application in the personalized treatment of breast cancer patients.

[Association of polymorphic markers rs7947461 of the TRIM21 gene and rs33996649 of the PTPN22 gene with the risk of developing exogenous dry eye syndrome]. / Assotsiatsiya polimorfnykh markerov rs7947461 gena TRIM21 i rs33996649 gena PTPN22 s riskom razvitiya sindroma sukhogo glaza ekzogennoi etiologii.

In this age of technological advancement, an increasing number of people is being exposed to external risk factors of damaging their ocular surface (wearing contact lenses, electromagnetic radiation from computers, mobile devices, etc.). However, the presence of external factors does not lead to a 100% risk of developing the dry eye disease (DED). The trigger mechanism in the development of autoimmune lesions of the ocular environment in some systemic diseases is known to be associated with molecular genetic factors. The search for molecular genetic disorders is based on the analysis of polymorphic markers of a number of genes responsible for the state of the eye surface. PURPOSE: To study the relationship of polymorphic markers rs7947461 of the TRIM21 gene and rs33996649 of the PTPN22 gene with the risk of developing dry eye syndrome of exogenous etiology. MATERIAL AND METHODS: The study included 57 people with exogenous risk factors for DED development. The control group included volunteers without a history of ophthalmic pathologies (n=75). Genotyping was done by real-time polymerase chain reaction followed by melting curve analysis. Statistical processing of data was done using the Statistica 6.1 RUS software for statistical analysis. RESULTS: In the course of the study, 31 patients of the main group were diagnosed with DED and separated into the 1st subgroup; DED diagnosis was not confirmed in 26 patients, who were put into the 2nd subgroup. The 1st subgroup showed a significant increase in the frequency of predisposing genotypes of the TRIM21 and PTPN22 genes. The relative risk of developing DED turned out to be 2.5 and 4.86 times higher, respectively. In the 2nd subgroup, no statistically significant data was found on the presence of predisposing genotypes of polymorphic markers of the TRIM21 and PTPN22 genes (p=0.3). CONCLUSION: The revealed association of polymorphic markers rs7947461 of the TRIM21 gene and rs33996649 of the PTPN22 gene with the risk of developing DED of exogenous etiology puts these loci as possible markers for diagnosing this pathology.

Relationship of the Levels of microRNA Gene Methylation with the Level of Their Expression and Pathomorphological Characteristics of Breast Cancer.

We studied the relationship of the levels of microRNA group expression and methylation with clinical and pathomorphological parameters of breast cancer and its immunohistochemical status. Quantitative methylation specific PCR analysis showed a significant (p<0.001) increase in the methylation level of 4 microRNA genes (MIR127, MIR129-2, MIR132, and MIR148A) and a significant (p<0.001) decrease for gene MIR375 relative to paired histologically normal tissue. Real-time PCR analysis revealed a significant (p≤0.001) decrease in the expression of 4 microRNAs (miR-127-5p, miR-129-5p, miR-132-3p, and miR-148a-3p) and a significant (p≤0.001) increase in the expression of miR-375-3p. A significant (rs=-0.6--0.7, p≤0.001) relationship between changes in the expression level of miR-129-5p, miR-132-3p, miR-148a-3p, and miR-375-3p and the levels of methylation of the corresponding genes in breast cancer was showed by using Spearman's rank correlation test. Analysis of the samples with consideration of the pathophysiological characteristics of the tumor revealed two significant markers of tumor progression: MIR129-2/miR-129-5p and MIR375/miR-375-3p. Both factors, the increase in the level of MIR129-2 methylation (p<0.001) and a decrease in the expression level of miR-129-5p (p<0.001), are significantly associated (p<0.001) with stage III/IV and the absence of HER2 expression. For MIR375/miR-375-3p, on the contrary, an association of low methylation level and enhanced expression with increased Ki-67 level (>30%, p<0.05) was revealed. These findings are of interest for understanding the mechanisms of breast cancer development and can provide the basis for the diagnosis and prognosis of the course of this disease. Moreover, the revealed features can be useful for adjusting the course of treatment with consideration of the pathophysiological characteristics of the tumor.

[Identification of Novel Differentially Expressing Long Non- Coding RNAs with Oncogenic Potential].

Recently, a wealth of data have been accumulating on the role of long non-coding RNAs (lncRNAs) in the fine-tuning of mRNA expression. Four new lncRNAs, namely, TMEM92-AS1, FAM222A-AS, TXLNB, and lnc-CCL28, were identified as differentially expressed in ovarian tumors using deep machine learning. The levels of lnc-CCL28 transcripts in both tumors and normal tissue samples were sufficient for further analysis by RT-PCR. In addition, the promising ovarian cancer biomarkers, lncRNAs LINC00152, NEAT 1 and SNHG17 were added to RT-PCR analysis. For the first time, an increase in the level of lnc-CCL28 and SNHG 17 lncRNAs was found in ovarian tumors, and the overexpression of LINC00152 and NEAT1 was confirmed. It seems that lnc-CCL28 is involved in carcinogenesis and, in particular, in ovarian cancer progression. Overexpression of LINC00152 and lnc-CCL28 was significantly associated with the later stages and metastasis.

Hypermethylation of Genes in New Long Noncoding RNA in Ovarian Tumors and Metastases: A Dual Effect.

The role of methylation in the regulation of genes of long noncoding RNA (lncRNA) is still poorly understood. We revealed new hypermethylated lncRNA genes in ovarian tumors and their effect on metastasis of ovarian cancer. A multiple and significant (p<0.001) increase in methylation of a group of lncRNA genes (MEG3, SEMA3B-AS1, ZNF667-AS1, and TINCR) was shown by quantitative methylation-specific PCR using the non-parametric Mann-Whitney test. Moreover, methylation of SEMA3B-AS1, ZNF667-AS1, and TINCR genes in ovarian cancer tumors was detected for the first time. Comparative analysis of 19 samples of peritoneal metastases and paired primary tumors showed a significant decrease in the methylation level of the same 4 genes: MEG3 (p=0.004), SEMA3B-AS1 (p=0.002), TINCR (p=0.002), and ZNF667-AS1 (p<0.001). Reduced methylation of suppressor lncRNA genes in peritoneal metastases is probably associated with the involvement of these lncRNA in the regulation of plastic reversion of the epithelial-mesenchymal transition to the mesenchymal-epithelial transition. Thus, the effect of lncRNA and their methylation on the development of tumors and metastases of ovarian cancer was demonstrated, which is important for understanding of the pathogenesis and mechanisms of metastasis of ovarian cancer. New properties of lncRNA can find application in the development of new approaches in the therapy of ovarian cancer.

The Role of ESR1 Gene Polymorphic Markers in the Development of Breast Cancer and Resistance to Tamoxifen Therapy.

We studied the effect of functionally significant polymorphic markers of the ESR1 gene on the risk of breast cancer, tamoxifen resistance, and survival of patients with this type of cancer. The study included 239 primary breast cancer patients without distant metastases. The analysis of genotype frequency distribution for the studied ESR1 gene polymorphic markers showed the association of the rs2228480 and rs2234693 markers with tamoxifen resistance in the group of patients with luminal B type breast cancer. An association of these two polymorphic markers with the risk of tumor development was also revealed; for rs2234693 polymorphic marker, a relationship with the survival of patients was also showed.

[Novel miRNAs as Potential Regulators of PD-1/PD-L1 Immune Checkpoint, and Prognostic Value of MIR9-1 and MIR124-2 Methylation in Ovarian Cancer].

Ovarian cancer (OC) is mostly detected at late stages weighed down with metastasis, and the five-year survival rate of patients is only 30%, which dictates the necessity to develop gentler and more selectively targeted drugs that current chemotherapeutic agents. The search for factors that can influence on the activity of the PD-1/PD-L1 immune checkpoint signaling pathway in tumors is relevant, and micro RNAs (miRNAs) play an important role in it. Over the past 5 years, only a few miRNAs (miR-34a, miR-145, and miR-424), which have a regulatory effect on the PD-1/PD-L1 system in OC patients, have been discovered. In present work, the methylation levels of 13 miRNA genes in 26 primary tumors and 19 peritoneal metastases of OC patients were determined and compared with the level of the soluble form of PD-L1 (sPD-L1) in the blood plasma of the same patients. It was shown that the methylation levels of five miRNA genes (MIR124-2, MIR34B/C, MIR9-1, MIR9-3, and MIR339) in tumors are in direct correlation with the sPD-L1 level in the blood plasma. In addition, when analyzing these five genes, a significant association of the methylation level of the MIR9-1 gene with a decrease in the three-year relapse-free survival, and a trend for decrease in the three-year survival rate with the methylation level of the MIR124-2 gene of OC patients were determined. Thus, the first data suggesting the role of inhibitors of the sPD-L1 immune checkpoint for five miRNAs (miR-124, miR-34b, miR-34c, miR-9, miR-339) and the possibility of using hypermethylated MIR9-1 and, presumably, MIR124-2 genes as independent prognostic markers of poor disease-free survival in OC patients were obtained.

The Role of Polymorphic Markers rs1478604, rs2292305, and rs2228262 in THBS1 Gene in the Development of Autoimmune Dry Eye Syndrome.

An association of polymorphic marker rs2228262 in the THBS1 gene with the risk of developing dry eye in Sjögren syndrome was revealed. Confocal microscopy data suggest that this polymorphic marker is responsible for the high probability of corneal nerve fiber lesion in Sjögren syndrome even in the absence of clinical and functional signs of dry eye syndrome. A significant correlation was established between polymorphic markers rs1478604, rs2228262 in THBS1 gene and the coefficients of anisotropy and orientation symmetry of corneal nerve fibers. These results allow considering these polymorphic markers as a genetic factor of predisposition to dry eye syndrome in patients with Sjögren syndrome.

Association of Molecular Genetic Markers of TP53, MDM2, and CDKN1A Genes with Progression-Free Survival of Patients with Ovarian Cancer after Platinum-Based Chemotherapy.

We studied the association of polymorphic markers of cell cycle control genes (Arg72Pro of the TP53 gene, T(-410)G of the MDM2 gene, and Ser31Arg of the CDKN1A gene) in ovarian cancer and progression-free survival following platinum-based chemotherapy. Tumor tissue samples obtained from 49 patients who had undergone chemotherapy were examined. Patients received standard platinum-based chemotherapy and were observed until disease progression. Polymorphic markers of genes were evaluated by PCR-RFLP and real-time PCR. In patients carrying the G allele of the T(-410)G marker of the MDM2 gene, a decreasing trend was observed in median progression-free survival. An increase in the median progression-free survival was observed in carriers of the Pro allele of the TP53 gene (p=0.045). Furthermore, a stronger association was noted with carriers of the minor Pro/Pro homozygous genotype relative to the Arg/Arg genotype (p=0.007). In the subgroup of patients who underwent optimal or complete cytoreductive surgery, carriage of the minor Arg allele of the Ser31Arg marker (CDN1A gene) was associated with a decrease in the median progression-free survival time (p=0.004).