A29
TP53and P21 polymorphisms and risk of lung cancer in an Iranian population
Farhad Mashayekhi, Zivar Salehi
University of Guilan, Rasht, Iran
Background
The TP53 tumor suppressor gene located at chromosome 17p13, plays a central role in response to DNA damage, maintaining host cell genomic stability after carcinogenic exposure. P53 protein can be activated by or interact with many other proteins in the signaling pathway network. Codon 72 polymorphism of the TP53 gene encodes either arginine (CGC) or proline (CCC) and these two allelic variants are structurally and functionally different, conferring different susceptibilities to cancer development. P53 is also responsible for the transcriptional induction of the P21. Mutations in either TP53 or P21 gene may affect the regulation of cellular proliferation, increasing the susceptibility to cancer.
Method
The genotypes of the Tp53 codon 72 and P21 codon 31 polymorphisms were identified using AS-PCR and PCR-RFLP, respectively. The number of 115 patients with lung cancer and non-cancer controls was included in this study.
Results
The Pro allele frequency was significantly higher among lung cancer patients than healthy controls (P value 0.024). There was no significant difference in Pro/Arg and Arg/Arg genotype frequency among patients and healthy controls (P value 0.041 and 0.026, respectively). The risk Pro homozygote for lung cancer was about 2 times against homozygote with adjusted odds ratio of 2.12 (95% CI-1.13-4.01). The p21 genotype frequencies in the non-cancer control were 0.51(Ser) and 0.49 (Arg).
Conclusion
Our data did not demonstrate on association of Arg allele of p21 polymorphism with lung cancer risk in Iran. This data suggested that the p21 codon 31 polymorphism may not play a significant role in cancer susceptibility and the prognosis of lung cancer patients in Iran. p53 Pro/Pro genotype is an independent risk factor for lung cancer in Iran.
