| Objective: Discussion on matrix hTERT rs2853676A/G、rs2853677C/T single nucleotide polymorphism and susceptibility of colorectal cancer.To provide the scientific basis for early diagnosis and individualized treatment of colorectal cancer.Methods: Between February 2014 and February 2016 in the Fourth Affiliated Hospital of Hebei Medical University, 162 cases of colon cancer patients, 209 cases of rectal cancer patients and 199 healthy people were chosen to participate in the case-control study. We collected from the participants matching the conditions of the experiment, with their informed consent, venous blood of 5 ml, as well as their age, gender, smoking, drinking, family history and other information. The proteinase K digestion-saturated nacl salting out method was applied to extract the DNA in white blood cells, and the Polymerase Chain Reaction-ligase Detection Reaction(PCR-LDR) was used to detect hTERT gene and analyze two SNP loci alleles and genotype of rs2853676A/G、rs2853677C/T.SPSS Ver21.0 software kit(SPSS Company in New York, Chicago, Illionis, USA) was used for statistical analysis of the experimental result. T-test was conducted on age differences between rectal cancer group, colon cancer group and health control group; chi-square test was carried out on gender differences between the two groups and the distribution of allele frequency and genotype frequency distribution; Hardy-Weinberg equilibrium analysis was performed by comparing the observed and expected genotype; unconditional logistic regression method was applied to calculate the odds ratio(OR) of relative risk degree with 95% confidence interval(CI); and EH software and 2LD software were adopted to analyze the two SNPs of hTERT gene rs2853676A/G、rs2853677C/T, with P<0.05 as the dividing line of a significant difference.Results:1 The genotype frequency distribution of rs2853676A/Gandrs2853677C/T met the Hardy-Weinberg equilibrium in the control group(P>0.05).2 The analysis of correlation between hTERT rs2853676A/G polym orphism and the risk of CRC.The frequencies of alleles A and G on hTERT rs2853676A/G in the rectal cancer group were 27.99% and 72.01% respectively, while in colon cancer group they were 31.48% and 68.52%, and in control 21.36% and 78.64%. There were statistical differences between the colorectal cancer group and the control group(P was 0.002 and 0.028 in both cases). In the rectal cancer group, the frequencies of genotypes A/G,A/A,G/G were 29.19%,13.40%,57.41% respectively,in the colon cancer group, the frequencies of genotypes A/G,A/A,G/G were 27.16%,17.90%,54.94% respectively and in control group, the frequencies of genotypes A/G,A/A,G/G were 37.69%,2.51%,59.80%.When compare the genotypes A/A,we found that there were statistical significant differences between the rectal cancer group and the control group or the colon cancer group and the control group(P <0.05).The people with genotype A/A suffered a higher risk of colorectal cancer.3 The analysis of correlation between hTERT rs2853677C/T polymo rphism and the risk of CRC.The frequencies of the alleles C and T on hTERT rs2853677C/T in the rectal cancer group were 36.60% and 63.40% respectively, while in colon cancer group they were 38.89% and 61.11%, and in control group 36.93% and 63.07%. There were no statistical difference between the rectal cancer group and the control group, or between the colon cancer group and the control group(P were 0.922 or 0.590 respectively). In the rectal cancer group, the frequencies of the C/T,C/C,T/T genotypes were 43.54%,14.83%,41.63% respectively, while they were 44.44%,16.67%,38.89% in colon group, and 47.74%,13.06%,39.20% in control group. Therefore, no statistical difference existed to support the argument that comparing with genotype C/T and(C/C+T/T), It meant people with genotype(C/C+T/T) shall suffer no higher risk of developing colon cancer.Conclusion:1 The gene hTERT rs2853676A/G polymorphism of may be associated with genetic susceptibility to colorectal cancer. The Allele A may be associated with genetic susceptibility to colorectal cancer. The A/A genotype increased the risk of colorectal cancer.2 The gene polymorphism of hTERT rs2853677C/T is not associated with genetic susceptibility to colorectal cancer. |
