Association of polymorphisms in TGFB1, XRCC1, XRCC3 genes and CD8 T-lymphocyte apoptosis with adverse effect of radiotherapy for prostate cancer.

The genetic background of each person might affect the severity of radiotherapy (RT)-induced normal tissue toxicity. The aim of study was to evaluate the influence of TGFB1 C-509T and Leu10Pro, XRCC1 Arg280His and XRCC3 Thr241Met polymorphisms as well as the level of radiation-induced CD8 T-lymphocyte apoptosis (RILA) on adverse effects of RT for prostate cancer (PCa). The study included 88 patients with localized or locally advanced PCa who were treated with RT. The polymorphisms were determined by PCR-RFLP analysis on DNA from peripheral blood mononuclear cells. RILA values were measured by flow cytometry. We found that CT genotype of TGFB1 C-509T could be protective biomarker for acute genitourinary (GU) and gastrointestinal (GI) radiotoxicity, while Thr variant of XRCC3 Thr241Met could predict the risk for acute GU radiotoxicity. Correlation between RILA values and toxicity was not detected. Univariate logistic regression analysis showed that Gleason score and risk group were risk factors for late GU, while for late GI radiotoxicity it was diabetes mellitus type 2. However, in multivariate model those were not proven to be significant and independent risk factors. Identification of assays combination predicting individual radiosensitivity is a crucial step towards personalized RT approach.

Increased circulating TGF-ß1 is associated with impairment in NK cell effector functions in metastatic melanoma patients.

Transforming growth factor beta (TGF-ß) plays a complex role in carcinogenesis. In 30 melanoma patients and 20 healthy controls (HC) we analysed functional and phenotypic characteristics of NK cells by Flow cytometry, gene expression of TGF-ß1 in peripheral blood mononuclear cells by qPCR and serum and supernatant level of free TGF-ß1 by ELISA. Melanoma patients had significantly higher serum level of circulatingTGF-ß1 compared to HC, especially those with metastasis into the central nervous system (subclass M1d) and high LDH serum values. Melanoma patients compared to HC had significantly higher level of TGF-ß1 gene in PBMC. TGF-ß1 serum values negatively correlate with NK cell activity analysed by CD107a (degranulation marker), IFN-γ, NKG2D, and NKp46 in patients. Study shows the association of high level of TGF-ß1 with NK cell inhibition in patients represents the main mechanism of tumour immune evasion. Targeting TGF-ß may become an important cancer treatment for improving antitumor immunity.

Evaluation of cytokine expression and circulating immune cell subsets as potential parameters of acute radiation toxicity in prostate cancer patients.

One of the challenges of radiation oncology in the era of personalized medicine is identification of biomarkers associated with individual radiosensitivity. The aim of research was to evaluate the possible clinical value of the associations between clinical, physical, and biological factors, and risk for development of acute radiotoxicity in patients with prostate cancer. The study involved forty four patients treated with three-dimensional conformal radiotherapy. The concentrations of IL-1ß, IL-2, IL-6, IFN-γ and TGF-ß1 were assessed before radiotherapy, after 5th, 15th and 25th radiotherapy fractions, at the end, and 1 month after the end of radiotherapy. Cytokine gene expression was determined in peripheral blood mononuclear cells. The univariate analysis of circulating cytokine levels during radiotherapy showed that increased serum concentrations of IL-6 were significantly associated with higher grade of acute genitourinary toxicity. The multivariate analysis demonstrated that increased level of IL-6 during the radiotherapy was significantly associated with higher grade of acute genitourinary toxicity across treatment. TGF-ß expression levels significantly decreased during course of radiotherapy. Research indicates that changes in circulating cytokine levels might be important parameter of radiotoxicity in patients with prostate cancer. These findings suggest that future studies based on multi-parameter examination are necessary for prediction of individual radiosensitivity.

Expression levels of genes involved in cell adhesion and motility correlate with poor clinicopathological features of epithelial ovarian cancer.

PURPOSE: Changes in the expression levels of genes involved in cancer cell adhesion and motility have been reported to have an important role in tumor progression. In this study, we aimed to investigate the clinical significance of ITGAV and CALD1 gene expression in epithelial ovarian cancer (EOC), the most lethal gynecological malignancy. METHODS: Reverse transcription quantitative polymerase chain reaction was used to evaluate ITGAV and CALD1 expression levels in 47 EOC and 19 benign formalin-fixed paraffin-embedded samples. We used Spearman's test to determine the association between ITGAV and CALD1 expression and Wilcoxon test to compare expression levels between malignant and benign ovarian tumor specimens as well as to determine their association with clinicopathological characteristics of EOC. Survival analysis was done by the Kaplan-Meier method and the log-rank test. P ≤ 0.05 was considered statistically significant. RESULTS: CALD1 and ITGAV showed significantly lower expression in EOC than in benign ovarian samples (p<0.001). Furthermore, CALD1 was significantly lower expressed in high-grade tumors (p=0.037) while there was a trend for a lower expression of ITGAV in tumors with high histological grade (p=0.043), in tumors with ascites (p=0.055), and in tumors of patients who relapsed (p=0.083). We also found a significant positive association between ITGAV and CALD1 expression (ρ=0.640, p<0.001) in EOC samples. Kaplan-Meier analysis showed no significant impact of ITGAV and CALD1 expression levels on overall survival of EOC patients (p=0.149 and p=0.430, respectively). CONCLUSION: Our findings indicate that CALD1 and ITGAV gene expression levels correlate with poor clinicopathological features of the EOC.

EGFR mutation testing from liquid biopsy of non-small cell lung cancer at the Institute for Oncology and Radiology of Serbia.

PURPOSE: Resistance to tyrosine kinase inhibitors (TKIs) in lung cancer often occurs, so mutation testing from liquid biopsy is the method of choice as a minimally invasive approach that quickly provides information for additional therapeutic options. The purpose of this study was to assess the success rate and usefulness of EGFR testing from liquid biopsy at the Institute for Oncology and Radiology of Serbia (IORS). METHODS: EGFR mutation testing was performed by real-time qPCR in 4750 tumor samples using the Cobas® EGFR Mutation Test v2. EGFR testing from 104 liquid biopsy samples was used to track the resistance on first-line EGFR-TKIs as well as for initial testing of 124 patients without tissue biopsies. RESULTS: Liquid biopsy samples were tested in cases with inadequate material for DNA isolation or without tissue biopsy at diagnosis. Nine mutated samples were detected (7.3 %) with a 99.2 % testing success rate. Testing liquid biopsy samples of patients who progressed on EGFR-TKIs showed an accordance rate of 67% with driver mutations, and 49% of mutated patients had the T790M mutation which rendered them eligible for third-generation EGFR-TKIs. An additional 5 patients tested EGFR wild type from plasma after progression were rebiopsied and 3 of them had the T790M mutation. CONCLUSIONS: EGFR mutation testing from liquid biopsy has been successfully implemented in Serbia and has proven invaluable for detecting molecular resistance mechanisms to EGFR-TKIs and as an alternative sample source for patients with scarce biopsy material or without any at all.

Association between miR-21/146a/155 level changes and acute genitourinary radiotoxicity in prostate cancer patients: A pilot study.

INTRODUCTION: Nearly sixty percent of patients with prostate cancer (PCa) undergo radiation therapy (RT). During the course of treatment patients may experience normal tissue reactions. It is a well established fact that genetic and epigenetic mechanisms, such as microRNA (miRNA) level changes might be associated with radiotoxicity, as a response to irradiation. MATERIALS AND METHODS: This is the first study that has investigated levels of radiosensory miRNAs in association with acute genitourinary radiotoxicity extracted from peripheral blood mononuclear cells (PBCs), in three points; before RT (BRT), after RT (ART) and on the first control examination (FCONT). We measured levels of miR-21/146a/155 expression by quantitative real-time PCR (qRT-PCR), comparative ΔΔCt method, in fifteen patients with localized prostate cancer, treated with three-dimensional conformal radiotherapy (3DCRT). Nine subjects have experienced acute genitourinary (GU) radiotoxicity whereas six where without GU radiotoxicity. RESULTS: Firstly, we detected the highest levels of miR-21 in ART group (p = 0.043) in the patients with acute GU radiotoxicity. Secondly, we found trend towards higher miR-21 levels and significantly higher levels of miR-146a/155 within the patients with acute GU toxicity than in patients without (p = 0.068, p = 0.016, and p = 0.010, respectively). Thirdly, we detected significant change in miR-146a/155 levels within the patients without acute GU radiotoxicity during RT p = 0.042, and p = 0.041, respectively). CONCLUSION: miR-21/146a/155 might be useful potential factors of radiosensitivity and acute genitourinary radiotoxicity in prostate cancer patients. miRNA might have great potential as predictors of various pathological conditions extracted from PBMCs.

Assessment of ovarian function after chemotherapy in women with early and locally advanced breast cancer from Serbia.

PURPOSE: Among harmful effects of chemotherapy is the reduction of ovarian function. The aim was to determine the serum levels of FSH, LH, estradiol and AMH after chemotherapy followed by endocrine therapy in breast cancer patients. METHODS: The study included 40 premenopausal hormone receptor-positive breast cancer patients aged 33-50 years. Anthracycline-based chemotherapy received 14/40 while anthracycline-taxane combination received 26/40 of patients, followed by tamoxifen (30/40) or tamoxifen plus goserelin (10/40). All of them experienced chemotherapy-induced secondary amenorrhea. Hormone levels were determined by ELISA. Statistics included Spearman's test, Mann-Whitney test and multiple linear regression analysis. RESULTS: Undetectable AMH levels were observed in 62.5 and 33.3% of patients with time period < 2 and ≥ 2 years from completion of chemotherapy to sample collection. Median levels of hormones for patients treated with anthracycline-based compared to anthracycline-taxane therapy were: 15.5 vs. 22.3 IU/L for FSH; 10.9 vs. 13.6 IU/L for LH; 55.5 vs. 39.5 pg/mL for estradiol; 0.11 vs. 0.11 ng/mL for AMH. The multiple linear regression showed that: women who received goserelin had significantly lower FSH; those with shorter time from completion of chemotherapy to sample collection had significantly higher LH and lower estradiol; younger women had higher AMH levels. CONCLUSIONS: The ovarian function was recovered from chemotherapy-induced secondary amenorrhea with time elapsed since the completion of adjuvant chemotherapy. It may be less disrupted in patients who received anthracycline-based chemotherapy and goserelin plus tamoxifen, as well.

Pharmacogenetics in cancer therapy - 8 years of experience at the Institute for Oncology and Radiology of Serbia.

PURPOSE: Pharmacogenetics is a study of possible mechanism by which an individual's response to drugs is genetically determined by variations in their DNA sequence. The aim of pharmacogenetics is to identify the optimal drug and dose for each individual based on their genetic constitution, i.e. to individualize drug treatment. This leads to achieving the maximal therapeutic response for each patient, while reducing adverse side effects of therapy and the cost of treatment. A centralized pharmacogenetics service was formed at the Institute for Oncology and Radiology of Serbia (IORS) with the aim to provide a personalized approach to cancer treatment of Serbian patients. METHODS: Analyses of KRAS mutations in metastatic colorectal cancer, EGFR mutations in advanced non-small cell lung cancer, CYP2D6 polymorphism in breast cancer, DPD polymorphism in colorectal cancer and MTHFR polymorphism in osteosarcoma have been performed by real time polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (PCR-RFLP). RESULTS: Mutation testing analyses were successful for 1694 KRAS samples and 1821 EGFR samples, while polymorphism testing was successful for 9 CYP2D6 samples, 65 DPD samples and 35 MTHFR samples. CONCLUSIONS: Pharmacogenetic methods presented in this paper provide cancer patients in Serbia the best possible choice of treatment at the moment.

Polymorphisms in cancer susceptibility genes XRCC1, RAD51 and TP53 and the risk of breast cancer in Serbian women.

BACKGROUND: Thanks to immense improvements in technology over the past few decades, we have witnessed a major shift towards the idea that breast cancer results from a combined effect of multiple common alleles conferring low risk. This study investigates the role of 3 nonsynonymous SNPs in the DNA repair genes XRCC1 (R399Q), RAD51 (G135C) and TP53 (Arg72Pro) in breast cancer in Serbian women. PATIENTS AND METHODS: Cases of BRCA1/2-negative hereditary breast cancer (n = 52), sporadic breast cancer (n = 106) and age-matched cancer-free female controls (n = 104) were obtained from the Institute for Oncology and Radiology of Serbia's blood bank. Restriction fragment length polymorphism analysis was used for genotyping. Descriptive analyses included genotype and allelic frequencies; the odds ratio and 95% confidence interval were calculated as an estimate of the relative risk. RESULTS: A significant difference in QQ+RQ versus RR genotype distribution of XRCC1 was observed between hereditary breast cancer patients and cancer-free controls. The association was confirmed among young breast cancer patients from these high-risk families. The existence of 3 recessive alleles in the RAD51 and XRCC1 genotype combination showed an association with hereditary breast cancer. Odds ratio analysis indicated a strong protective role of the RAD51 GG + TP53 ArgArg + XRCC1 RR combined genotype against hereditary breast cancer negative for BRCA1/2 mutations. CONCLUSIONS: The XRCC1 R399Q polymorphism showed an association with increased breast cancer risk in Serbia, especially in the hereditary form of the disease and in young breast cancer patients. Dominant alleles of RAD51, TP53 and XRCC1 combined genotypes indicated a strong protective role against hereditary breast cancer.

Impact of RAD51 G135C and XRCC1 Arg399Gln polymorphisms on ovarian carcinoma risk in Serbian women.

OBJECTIVE: The polymorphic variations of DNA repair genes may contribute to functional deficiencies in DNA repair processes increasing susceptibility to cancer. We aimed to investigate the impact of 135G>C RAD51 and XRCC1 Arg399Gln polymorphisms on ovarian carcinoma risk in Serbian women. METHODS: The study included 50 ovarian carcinoma samples and 78 cervical swabs of gynecologically healthy age-matched controls. RAD51 G135C and XRCC1 Arg399Gln polymorphisms were determined by PCR-RFLP. Deviations of the genotype frequencies from Hardy-Weinberg equilibrium were assessed using the χ2 test. The allele- and genotype-specific risks were estimated as odds ratios with 95% confidence intervals. RESULTS: RAD51 135C and XRCC1 Arg allele are associated with ovarian carcinoma [OR (95% CI): 2.54 (1.22-5.29) for C vs. G; 2.64 (1.53-4.55) for Arg vs. Gln]. RAD51 C exerts its effect in dominant (CC plus GC vs. GG) [OR (95% CI): 2.83 (1.21-6.62], while XRCC1Arg in dominant (ArgArg plus ArgGln vs. GlnGln) [OR (95% CI): 4.76 (1.69-13.42)] and recessive model (ArgArg vs. ArgGln plus GlnGln) [OR (95% CI): 2.21 (1.07-4.56)]. CONCLUSION: The results suggest that the RAD51 G135C and XRCC1 Arg399Gln polymorphisms could be biomarkers of susceptibility for ovarian carcinoma development. Further larger case-control study is needed to confirm our findings.

Overall human papilloma virus and types 16/18 prevalence in women with normal cervical cytology in Serbia: is it time for human papillomavirus testing and/or vaccination?

PURPOSE: Infection with high-risk human papilloma viruses (HR-HPV), especially types 16/18, is the main factor in cervical carcinogenesis. Although the incidence of cervical cancer in Serbia is among the highest ones in Europe, data about HPV infection are insufficient. The aim of this study was to investigate the presence of overall and HPV16/18 infections in women with healthy appearance and cytologically (Pap) normal cervix. METHODS: The study was performed on women who participated in this cervical cancer screening pilot study. Cervical HPV infection was detected by GP5+/6+ PCR. HPV16/18 were detected by amplification of E7/E1 viral gene, respectively. RESULTS: In 350 women we got the following results: cytological abnormalities (10.3%); visible cervical changes (20.3%); previous precancerous lesion (2.3%); normal Pap and speculum finding without history of precancerous lesion (67.1%). In the last group overall HPV prevalence was 41.3%, with 10.5% HPV16 and 23.7% HPV18. The rate of multiple HPV16 plus HPV18 infections was 2.6%. HR-HPV16/18 comprised 31.6% of the total HPV positive participants. CONCLUSION: Owing to the high prevalence of overall and HPV16/18 infections in women with healthy appearance and cytologically normal cervix, we postulate that testing/ prophylaxis for these HR-HPV types could be introduced in cervical cancer screening and preventive programmes in Serbia.

The influence of methylenetetrahydrofolate reductase and thymidylate synthetase gene polymorphisms on lung adenocarcinoma occurrence.

PURPOSE: Methylenetetrahydrofolate reductase (MTHFR) and thymidylate synthetase (TYMS) are suggested as risk factors for lung cancer. The purpose of this study was to analyze the association of MTHFR C677T polymorphism and variable number tandem repeat 2R/3R and single nucleotide polymorphism G>C in the 3R allele of the TYMS gene with lung adenocarcinoma. METHODS: A case-control study including lung adenocarcinoma patients and healthy subjects was performed. Restriction fragment length polymorphism analysis was used for genotyping. Descriptive analyses included genotype and allelic frequencies; the odds ratio and 95% confidence interval were calculated as an estimate of relative risk. Significance was set at p<0.05. RESULTS: A significant difference in CC vs TT+CT MTHFR genotype distribution was observed between patients and controls. There was no significant association between the TYMS polymorphisms and the risk of lung adenocarcinoma. CONCLUSIONS: The MTHFR 677T allele is likely to have a protective effect against lung adenocarcinoma development.

RAD51 135G>C and TP53 Arg72Pro polymorphisms and susceptibility to breast cancer in Serbian women.

Breast cancer is a complex disease with both genetic and environmental factors involved in its etiology. An important role of polymorphisms in genes involved in DNA repair has been reported related to breast cancer risk. We conducted a case-control study in order to investigate the association of RAD51 135G>C and TP53 Arg72Pro polymorphisms with breast cancer in Serbian women.48 BRCA negative women with breast cancer and family history of breast/ovarian cancer (hereditary group), 107 women with breast cancer but without family history of the disease (sporadic group) and 114 healthy women without a history of the disease (control group) were included. Restriction fragment length polymorphism was used for genotyping. Genotype and allelic frequencies, the odds ratio (OR) and the 95 % confidence interval (CI) were calculated as an estimate of relative risk. The Hardy-Weinberg equilibrium was tested using χ(2) test. Significance was considered for p < 0.05. RAD51 135G>C showed statistically significant association of CC genotype and increased breast cancer risk (OR 10.28, 95 % CI 1.12-94.5) in hereditary group of patients compared to the control group. Regarding the TP53 Arg72Pro, we showed statistical significance for ProPro + ProArg comparing to ArgArg (OR 2.34, 95 %, CI 1.17-4.70) in hereditary compared to sporadic group. RAD51 135G>C contributes to hereditary breast cancer in Serbian population, with CC genotype as a risk factor. We also found that carriers of Pro allele of TP53 codon 72 is related to hereditary cancer comparing to sporadic one, which indicates it as a potential risk factor for hereditary form of disease.

Serbian high-risk families: extensive results on BRCA mutation spectra and frequency.

Mutations in BRCA genes elevate risk for breast and ovarian cancer. These mutations are population specific. As there are no data on BRCA mutation screening on larger number of probands in Serbia to date, aim of this study was to determine types and frequencies of BRCA mutations in individuals from high-risk families from Serbia, as well as to determine which BRCA mutations may be considered as founder for Serbian population. We analyzed 94 probands and detected 9 frameshift mutations in 12 individuals, 1 benign BRCA2 nonsense mutation and numerous missense and synonymous mutations in both genes. Frequency of frameshift mutations is 12.77%. In addition to two novel mutations detected in our population we reported previously, we detected another novel mutation--c.7283delT in BRCA2 exon 14. None of the detected deleterious mutations may be considered as founder mutations for Serbian population, as each of them was found in no more than two high-risk families. This mutation diversity is most probably due to high migration rate in history of this part of Europe. Interpretation of genetic testing results with missense mutations of unknown clinical importance is very challenging and should be approached with caution, using all available data sources for results' interpretation.

TP53 codon 72 polymorphism and risk of cervical carcinoma in Serbian women.

PURPOSE: It was shown that individuals homozygous for the Arg-encoding allele of codon 72 TP53 gene may have an increased risk to human papillomavirus (HPV)-related cervical carcinomas. However, many studies have failed to confirm this hypothesis. The aim of this study was to investigate a role of the TP53 codon 72 polymorphism in cervical carcinoma development in Serbian women. METHODS: In comparative, prospective study, we analyzed 49 wild type TP53 gene cervical carcinomas samples and 74 cervical smears of gynecologically healthy women. DNA was extracted by salting-out procedure. Codon 72 polymorphism was assessed by Restriction Fragment-Length Polymorphism method. Presence of HPV infection was detected through amplification of one part of L1 viral gene. χ(2) and odds ratio were used for statistical analysis. RESULTS: The distribution of Arg/Arg, Arg/Pro, and Pro/Pro genotypes of codon 72 of TP53 gene was: 63.3, 34.7, and 2.0 % in the cervical carcinomas and 58.1, 33.8, and 8.1 % in the control group. We observed an increased risk for the development of cervical carcinoma for Arg homozygotes in relation to heterozygotes plus Pro homozygotes (OR 1.24; 95 % CI 0.59-2.61) and higher one for Arg/Arg plus Arg/Pro genotype in relation to Pro homozygotes (OR 4.24; 95 % CI 0.49-36.32). CONCLUSIONS: The results indicate that carriers of Arg allele of codon 72 TP53 gene have an increased risk for development of cervical carcinoma in Serbian women. However, the influence is not statistically significant and requires analysis of larger case-control group.

The usability of allele-specific PCR and reverse-hybridization assays for KRAS genotyping in Serbian colorectal cancer patients.

BACKGROUND: Colorectal cancers (CRCs) with wild-type KRAS respond to EGFR-targeted antibody treatment. Analysis of the hotspot clustered mutations in codons 12 and 13 is compulsory before therapy and no standardized methodology for that purpose has been established so far. Since these mutations may have different biological effects and clinical outcome, reliable frequency and types of KRAS mutations need to be determined for individual therapy. AIMS: The purpose of this study was to describe the KRAS mutation spectrum in a group of 481 Serbian mCRC patients and to compare the general performances of allele-specific PCR and reverse-hybridization assays. METHODS: KRAS testing was performed with two diagnostic analyses, DxS TheraScreen K-RAS PCR Kit and KRAS StripAssay™. RESULTS: KRAS mutations in codons 12 and 13 were present in 37.6 % of analyzed formalin-fixed paraffin-embedded (FFPE) DNA samples. The seven most frequent mutation types were observed with both assays: p.G12D 34.6 %, p.G12V 24.9 %, p.G12A 10.3 %, p.G12C 8.1 %, p.G12S 5.4 %, p.G12R 1.6 %, and p.G13D 15.1 %. Regarding double mutants, 0.8 % of them were present among all tested samples and 2.2 % among KRAS mutated ones. CONCLUSIONS: Two screening approaches that were used in this study have been shown as suitable tests for detecting KRAS mutations in diagnostic settings. In addition, they appear to be good alternatives to methods presently in use. In our experience, both methods showed capacity to detect and identify double mutations which may be important for potential further subgrouping of CRC patients.

Association of TP53 codon 72 polymorphism with susceptibility to ovarian carcinomas in Serbian women.

OBJECTIVES: Finding a potential genetic factor associated with a deadly disease, such as ovarian carcinoma, is of particular importance. The aim of this study was to examine the role of the TP53 codon 72 polymorphism in ovarian carcinoma development in Serbian women. STUDY DESIGN: 47 wild-type TP53 gene ovarian carcinoma samples and 70 cervical smears from gynecologically healthy women were analyzed. DNA was extracted by a salting-out procedure. Codon 72 polymorphism was assessed by PCR-RFLP method. χ(2), Fisher exact test and odds ratio were used for statistical analysis. RESULTS: The distribution of Arg/Arg, Arg/Pro and Pro/Pro genotypes of codon 72 of the TP53 gene was: 46.8%, 46.8% and 6.4%, respectively in the ovarian carcinomas and 64.3%, 31.4% and 4.3%, respectively in the control group. We observed an increased risk for the development of ovarian carcinoma for Pro homozygotes in relation to heterozygotes plus Arg homozygotes (OR=1.52; 95% CI 0.29-7.89) and a higher one for Pro/Pro plus Arg/Pro genotype in relation to Arg homozygotes (OR=2.04; 95% CI 0.96-4.34). CONCLUSION: The results showed no association between codon 72 TP53 gene polymorphism and risk for development of ovarian carcinoma in Serbian women. However, this observation requires further analysis of a larger case-control study group.

Detection and genotyping of human papillomaviruses and their role in the development of ovarian carcinomas.

PURPOSE: The objective of this study was to investigate the presence of human papillomavirus (HPV) infection in ovarian carcinoma samples from Serbian women and correlate them with clinicopathological characteristics of disease and patients' characteristics. METHODS: Fifty-four ovarian carcinoma patients were included in the study. DNA was isolated by salting out method from tumor tissue obtained after surgical treatment. Presence of HPV infection was detected through polymerase chain reaction amplification of a 150-bp fragment of L1 viral gene by GP5+/GP6+ primers. HPV genotyping was performed by DNA sequencing. RESULTS: HPV DNA was present in 4/54 (7.4 %) ovarian carcinomas. All HPV-positive tumors contained high-risk HPV16 type. HPV infection was more common in advanced opposite to localized disease. The median age of diagnosis of disease varied from 57 years for patients with HPV infection to 59 years for patients without HPV infection. CONCLUSIONS: Our results indicate that HPV infection may play a limited role in ovarian carcinogenesis.

Association between methylenetetrahydrofolate reductase polymorphism C677T and risk of chronic myeloid leukemia in Serbian population.

Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme regulating the intracellular folate metabolism which plays an important role in carcinogenesis through DNA methylation and nucleotide synthesis. The common MTHFR single nucleotide polymorphism C677T has been reported to be associated with reduced enzymatic activity. In order to investigate the influence of this polymorphism on the risk of chronic myeloid leukemia (CML), we performed a case-control study in a Serbian population of 52 patients with CML and 53 healthy control subjects. MTHFR C677T polymorphism genotyping was assessed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The results demonstrated no statistical difference in MTHFR 677 frequency distribution between patient and control groups. Our findings suggest that MTHFR 677 gene variants have no significant influence on the susceptibility to CML in a Serbian population.