Gokhan Ozan Cetin

Pamukkale University, Denisli, Denizli, Turkey

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Publications (6)12.69 Total impact

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    ABSTRACT: Bladder cancer is the one of the most common cancers worldwide and O6-Methylguanine DNA Methyltransferase (MGMT) promoter methylation might be contributing to clinicopathological features of the disease. We analyzed formalin-fixed, paraffin-embedded bladder tissue samples from 101 patients with urothelial carcinoma. All samples were analyzed by real-time methylation-specific PCR. MGMT promoter methylation was detected in 15 (14.9%) of the samples and was not significantly different between any of the groups, although the number of high grade tumors with MGMT promoter methylation was twice the number of low grade tumors. Methylation of MGMT in high grade tumors might play a role in aggressive proliferation of the tumor cells and a poor prognosis.
    No preview · Article · Jan 2014 · Gene therapy & molecular biology
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    ABSTRACT: A 30-year-old male patient referred to our clinic for unraveling the underlying etiology of the azoospermia. He had no unusual medical history. At physical examination, obesity, short neck and gynecomastia were noted. All hormone levels were normal except estradiol which was 2-fold higher than the upper limit. Having azoospermia in the spermiogram, scrotal ultrasonography was normal. Cytogenetic analysis and fluorescence in situ hybridization were performed subsequently, 45,X,add(21)(p10) and 45,X,add(21)(p10).ish der(Y;21) (q12;p10) were found, respectively. On C-banding, dicentric staining of translocated chromosome was observed. NOR banding was negative. Molecular genetics studies using multiplex polymerase chain reaction revealed the presence of Y chromosome sequences at SRY, AZFa, AZFb, AZFc regions.
    No preview · Article · Dec 2012 · Turkiye Klinikleri Journal of Medical Sciences
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    ABSTRACT: DNA repair plays a key role in prevention of carcinogenesis and one of the most important DNA repair mechanisms is nucleotide excision repair (NER) pathway. This pathway includes a number of genes such as excision repair cross-complementing group 1 (ERCC1) gene which are responsible for the 5' incision of damaged DNA. A reduced DNA repair capacity associated with ERCC1 mRNA level has been observed in lung carcinogenesis. Two single nucleotide polymorphisms (SNPs) in ERCC1 gene, T19007C (rs11615) and C8092A (rs3212986), reportedly predict to affect the mRNA of ERCC1 in non-small cell lung cancer (NSCLC). To examine the role of two common SNPs in ERCC1 gene further, we conducted this study where 80 cases histopatologically diagnosed as NSCLC were genotyped. Genomic DNA was extracted from formalin-fixed, paraffin embedded tissues and two SNPs were analyzed using real-time PCR. The distributions of TT, TC, and CC genotypes of the T19007C SNP were 40, 44 and 16%, respectively. Significantly increased frequency of the patients carrying at least one 19007C allele was observed in early stage compared to advanced stage (P=0.002). And also, the frequency of TC and CC genotypes significantly increased in younger patients compared to older patients (P=0.035). Regarding C8092A SNP, the distribution of CC, CA, and AA genotypes was 38, 51 and 11%, respectively. There was no significant difference in the genotype distribution between C8092A SNP and clinicopathological parameters. This study indicated that harboring at least one 19007C allele may have protective effect in NSCLC.
    No preview · Article · May 2011 · Molecular Biology Reports
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    ABSTRACT: Excision Repair Cross-Complementing Group 1 (ERCC1) is an important DNA repair gene, playing critical role in nucleotide excision repair pathway and having a significant influence on genomic instability. Some studies support that ERCC1 might be a potential predictive and prognostic marker in non-small cell lung cancer (NSCLC). ERCC1 has also been shown to be a promising biomarker in NSCLC treated with a cisplatin-based regimen. Therefore, the determination of ERCC1 expression at DNA, mRNA and protein level in different stages of NSCLC is still an important topic in the cancer. Ninety-one formalin-fixed paraffin-embedded tumor samples histopathologically diagnosed as NSCLC were examined in this study. ERCC1 expression at protein level were scored by immunohistochemistry. The gene amplification and mRNA expression levels for ERCC1 were determined by real-time quantitative PCR. There was complete concordance among the three methods in 39 tumor samples (42.9%). A strong correlation was found between DNA amplification and mRNA expression (r=0.662) while there was no correlation between mRNA and protein assessment for ERCC1 expression (r=-0.013). ERCC1 expression at mRNA and DNA level (63.1 and 84.2%, respectively) in tumors at stage III was higher than at the other stages. In contrast, the protein expression at stage II and III (56.6 and 52.6%, respectively) of NSCLC was lower than that of tumors with stage I NSCLC. These results show that the mechanism by which ERCC1 expression might play a role in tumor behavior. This study was also confirmed that the appropriate validation and qualification in methods used for ERCC1 status were needed before its clinical application and implementation.
    No preview · Article · May 2011 · Molecular Biology Reports
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    ABSTRACT: This population-based study on parkinsonism in a genetically isolated community from a rural area of Turkey aimed to provide a selective evaluation of environmental and heritable risk factors. An increased prevalence of parkinsonism (4.1%) was detected in the village of Kizilcaboluk for people 65 years of age and older. This study included 36 patients with parkinsonism living in Kizilcaboluk and three times that number of age- and sex-matched people serving as controls. A questionnaire including demographic data, family history, education, occupation, data on exposures to pesticides, smoking, alcohol intake, and head trauma was administered. We found a significant association of parkinsonism cases with a positive family history in first-degree relatives (odds ratio [OR], 7.48; 95% confidence interval [CI], 2.52-22.17; P < 0.0001) and with pesticide exposure (OR, 2.96; 95% CI, 1.31-6.69; P = 0.015) compared to the control subjects. The value of genetically isolated populations for the identification of genetic risk factors for common and complex disorders has gained much attention recently because the genetic make-up of these populations is likely to be less complex than that of the general population and our findings should prompt investigations to the nature of a familial aggregation of parkinsonism in this population.
    No preview · Article · Jul 2003 · Movement Disorders
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    ABSTRACT: Cytogenetic studies in patients with reproductive failure To investigate the contribution of chromosomal abnormalities in sub fertility and in couples with repeated abortions. Hundred and 13 couples who had at least two or more spontaneous abortions and 65 women and 63 men with infertility were analyzed cytogenetically. Major chromosomal rearrangements were found in 8% and minor variants in 6% in the study population. Major chromosomal aberrations were judged to explain 4.9% of recurrent abortions and 13% of infertility. Chromosomal abnormalities in infertile men occurred in 5% and in infertile women in 21.5%. The chromosomal abnormalities were structural (57%), numerical (18%) or mosaics (25%). Chromosomal aberrations in recurrent abortions are mostly structural ones and those in female infertility mosaicism of sex chromosomes. Turner's syndrome, Turner variants and XY females are detected as a cause of female infertility. The structural and numerical aberrations of either sex or autosomal chromosomes were found in infertile men.
    No preview · Article · Feb 2003 · Acta Obstetricia Et Gynecologica Scandinavica