Study of association between codon31 of p21 (rs 1801270) gene single nucleotide polymorphisms (SNP) with the risk of colorectal cancer in khuzestan province
Study of association between codon31 of p21 (rs 1801270) gene single nucleotide polymorphisms (SNP) with the risk of colorectal cancer in khuzestan province
Introduction: Cancer is in most cases one of the most deadly diseases that causes many problems to the patient in terms of quality of life and imposes huge economic costs on the patient's family and society.
Cancer occurs as a result of uncontrolled proliferation of cells and is the second leading cause of death in the world, and one of the most deadly types of cancer is colon cancer. One of the most important proteins involved in fighting cell cancer is the p21 protein, and a defect in the activity of this protein can cause changes in its structure and activity.
Methods: In this study, this polymorphism was studied among the population with colorectal cancer in Khuzestan province by RFLP method. For this purpose, 112 patients with colorectal cancer and 100 control samples of polymorphism were studied. After sampling, osmotic shock or ionic detergents were used to extract the cell extract. The DNA-bound proteins were then digested and the cellular proteins were precipitated by phenol and chloroform or saturated NaCl (6 M), and finally, the DNA was precipitated with cold ethanol. To evaluate the quantity and quality of DNA, electrophoresis methods on agarose gel and nanodrop spectrophotometry were used. In this experiment, the polymorphism of the P21 gene was studied and part of the sequence of this gene was PCR, which contained the desired nucleotide, and after sectioning, the band difference was detected by the restriction enzyme. After performing RFLP and observing the pattern of different bands, sequences related to different patterns were sequenced and the results were compared with the natural gene sequence available at the NCBI site and the relevant genotype was determined. The experimental results were analyzed using SPSS software, version 21.
Results: PCR results of P21 gene showed that this gene contains a sequence with 221 nucleotides and the BIPI restriction enzyme cleaves the sequence when the target nucleotide is G; Therefore, the presence of a 221 nucleotide band on the gel electrophoresis indicates the cytosine amino acid codon, and the presence of 98 and 123 bp bands on the gel electrophoresis indicates arginine in the 21 codon of the P21 gene. Also, seeing three bands 221, 98 and 123 pairs of games indicates that the sample is heterozygous in this case. The amount of chi-square (chi-square) obtained by comparing the frequencies of the two groups in the three types of p21 gene genotype is equal to 3.855. Given that the level of significance (p-value) is greater than 0.05; Therefore, there is no statistically significant difference between genotype in control group and patient in terms of p21 gene genotype.
Conclusion: Polymorphism in codon 31 (rs 1801270) is the most studied of the polymorphisms in this gene. During this polymorphism, C is displaced by A in the third codon of the p21 gene 31, and serine is unequivocally converted to arginine in a DNA-binding zinc finger motif. In this study, no significant difference was observed between patients with colorectal cancer and the control group in c21 polymorphism of p21 gene and codon 31 polymorphism of p21 gene did not show any effect on colorectal cancer in Khuzestan province.