DNA repair genes polymorphisms and risk of colorectal cancer in Saudi patients.

BACKGROUND AND STUDY AIMS: Polymorphisms in the DNA repair genes may influence individual capacity to repair DNA damage, which may be associated with increased genetic instability and carcinogenesis. Our aim was to evaluate the relation of genetic polymorphisms in 2 DNA repair genes, XPD Lys751Gln and XRCC1 (A399G), with colorectal cancer (CRC) susceptibility. We further investigated the potential effect of these DNA repair variants on clinicopathological parameters of CRC patients. PATIENTS AND METHODS: Both XPD and XRCC1 polymorphisms were characterised in one hundred CRC patients and one hundred healthy controls who had no history of any malignancy by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method and PCR with confronting two-pair primers (PCR-CTPP), using DNA from peripheral blood in a case control study. RESULTS: Our results revealed that the frequencies of GG genotype of XRCC1 399 polymorphism were significantly higher in the CRC patients than in the normal individuals (p⩽0.03), and did not observe any association between the XPD Lys751Gln polymorphism and CRC risk. We found association between both XRCC1 A399G polymorphisms and histological grading of disease. CONCLUSION: Our results suggested that, XRCC1 gene is an important candidate gene for susceptibility to colorectal carcinoma.

Vitamin D receptor gene polymorphisms and steroid receptor status among Saudi women with breast cancer.

The vitamin D receptor (VDR) is a mediator for the cellular effects of vitamin D and interacts with other cell signaling pathways that influence cancer development. We evaluated the associations of the FOK1 and Taq1 VDR polymorphisms and breast cancer risk and possible effect modification by steroid receptor status of the tumor. This case-control study includes 95 breast cancer patients and 100 age-matched controls. Genotyping for VDR FOK1 and Taq1 polymorphisms was performed using polymerase chain reaction-based restriction fragment length polymorphism. Level of 25(OH)D in serum was determined using ELISA. Immunohistochemical studies were performed for estrogen receptors (ER) and progesterone receptors (PR). The frequencies of ff genotype were significantly increased in the breast cancer group compared to the control group. Carriers of the f allele were significantly more likely to develop BC. We observed a statistically significant interaction for the Fok1 polymorphism and ER status. Our results demonstrated that FOK1 f. genotype and f allele have an important role in breast cancer risk in Saudi patients.

COX-2 polymorphisms -765G→C and -1195A→G and hepatocellular carcinoma risk.

Cyclooxygenase-2 (COX-2) is overexpressed in hepatocellular carcinoma (HCC) and considered to play a role in hepatic carcinogenesis. Our aim was to examine the associations between polymorphisms in COX-2 -765G→C and -1195A→G and risk of HCC. We conducted a case-control study including 120 patients with HCC and 130 age- and gender-matched controls. Genotypes of the COX-2 polymorphisms -765G→C and -1195A→G were determined by polymerase chain reaction-based restriction fragment length polymorphism. No significant difference was observed in the genotype distribution of the -765G→C polymorphism between patients and controls. The -1195AA genotype was associated with an increased risk of developing HCC (OR, 2.5; 95%CI, 1.18-5.37). The A allele was present significantly more often in HCC patients (OR 1.5; 95%CI, 1.05-2.14). In conclusion, our results demonstrated that the -1195AA genotype and A allele have an important role in HCC risk in Egyptian patients.