en Genetics Original Article Original Article <span style="font-size:14px;"><span style="font-family:times new roman;"><span style="color:#0000FF;"><strong><em>Background: </em></strong></span>Ovarian carcinoma is one of the leading causes of cancer-related death among females. K-ras codon 12 mutations are commonly occurring mutations in different types of cancers and leads to resistance against anti-EGFR therapeutics. Hence, determination of mutations in k-ras gene is crucial for predicting response to anti-EGFR therapies. This study aimed to evaluate the prevalence of k-ras gene mutations and CA125 tumor marker in patients with ovarian carcinoma in Tabriz city.<br> <span style="color:#0000FF;"><strong><em>Methods</em></strong><em>:</em></span> Genomic DNA was extracted from 67 tissues pertained to women with ovarian carcinoma. Mutations in codon 12 and 13 of k-ras gene were analyzed by Nested PCR and RFLP methods. Titer of CA125 tumor marker was determined by ELISA.<br> <span style="color:#0000FF;"><strong><em>Results</em></strong><em>:</em> </span>Among the 67 patients, 7 patients (10.4%) had mutation in k-ras codon 12 while none of them had mutation in k-ras codon 13. Based on the results, the frequency of various genotypes were 89.55%, 10.44%, and 0%, for GG, GA, and AA alleles, respectively. The<em> p-value</em> for stage I and Grade I tumors were 0.022 and 0.04, respectively, indicating a statistically significant correlation between codon 12 mutation and stage I and Grade I tumors. Furthermore, we found significant correlations among CA125 tumor marker titers and histological grade (p<0.000) and stage (p<0.000). The mean serum CA125 tumor marker levels in malignant carcinomas were 499.84 U/ml.<br> <span style="color:#0000FF;"><strong><em>Conclusion</em></strong><em>:</em> </span>The results in this study indicated high prevalence of k-ras codon 12 mutations and high titer of CA125 tumor marker in patients with ovarian carcinoma in the study region.</span></span><br> &nbsp; CA125, codon 12, k-ras, RFLP, ovarian carcinoma. 75 82 http://caspjim.com/browse.php?a_code=A-10-1312-1&slc_lang=en&sid=1 Nazanin Bagherlou nznnbagherlou@gmail.com 100319475328460019937 100319475328460019937 No Department of Biology, Faculty of Sciences, University of Mohaghegh Ardabili, Ardabil, Iran Safar Farajnia farajnias@tbzmed.ac.ir 100319475328460019938 100319475328460019938 Yes Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran Saber Zahri zahri@uma.ac.ir 100319475328460019939 100319475328460019939 No Department of Biology, Faculty of Science, University of Mohaghegh Ardabili, Ardabil, Iran Ali Dastranj Tabrizi dastranjt@gmail.com 100319475328460019940 100319475328460019940 No Department of pathology, Tabriz University of Medical Science, Tabriz, Iran Atefeh Nazari tfh_nzr@yahoo.com 100319475328460019941 100319475328460019941 No Biotechnology Research Center, Tabriz University of Medical Science, Tabriz, Iran