Investigation of GSTP1 and PTEN gene polymorphisms and their association with susceptibility to colorectal cancer.

Background: This study investigates the association of single nucleotide polymorphism in glutathione S transferase P1 (rs1695 and rs1138272) and phosphatase and TENsin homolog (rs701848 and rs2735343) with the risk of colorectal cancer (CRC).

Patients and methods: In this case-control study, 250 healthy controls and 200 CRC patients were enrolled. All subjects were divided into 3 groups: healthy control, patients, and overall (control + patients). Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The demographic information, including age, gender, location, smoking status, cancer stage, and node involvement, were collected.

Results: The allele frequencies of PTEN rs701848 in overall subjects were 0.78 for C and 0.22 for T. Similarly, in overall individuals, allele frequencies for PTEN rs2735343 were 0.65 and 0.35 for G and C alleles, respectively. The CC genotype or C allele of rs701848 and CG/GG genotype of rs2735343 were observed to be a risk factor for CRC. In overall individuals, a significant (p ≤ 0.05)) association was observed between rs701848 and rs2735343 polymorphisms CRC. Allele frequencies for GSTP1 rs1695 were 0.68 and 0.32 for the A and G alleles, respectively. Allele frequencies for GSTP1 rs1138272 were 0.68 and 0.32 for C and T alleles, respectively. However, a significant (p < 0.05) association was found in males for rs1695, while a non-significant difference was observed for the distribution of any genotypes or alleles at GSTP1 (rs1138272).

Conclusions: Both SNPs of PTEN rs701848 and rs2735343 polymorphisms were significantly associated with CRC. However, in GSTP1, rs1695 was significantly associated with CRC risk in males, and rs1138272 showed a non-significant association with colorectal cancer risk.