Frequency of I655V SNP of HER-2/neu in colorectal cancer: a study from India

Abstract

The present study was conducted to determine the prognostic significance of I655V SNP (rs1136201) is a genetic one in HER-2 oncoprotein in cases of colorectal cancer (CRC). We conducted a case-control study analysing 83 subjects (naïve primary CRC cases) who underwent CRC biopsy/colectomy and included 57 healthy control subjects. Analysis of HER-2 polymorphism was done by PCR-RFLP technique. The mean age was found to be 55.9 years; median age was 56 years and mode age was 54 years with a range of 43 (30-73). Males constitute 63 (75.9%) and females constitute 20 (24.1%) of patient population. According to gradewise distribution, 12 (14.45%) patients were of Grade I, 53 (63.85%) of Grade II, and 18 (21.68%) were of Grade III. We found out that out of 83 patients, 52 (62.65%) were of homozygous wild type (A/A; Ile/ Ile); 27 (32.53%) were of heterozygous type (A/G; Ile/Val) and 4 (4.81%) were of homozygous mutant type (G/G; Val/Val). Allelic frequency of Ile (A) was found out to be 0.79 and that of Val (G) is 0.21 and were not significantly different from the healthy control population. Fischer's exact p value obtained was 0.86.

Association of HER1 and HER2 Gene Variants in the Predisposition of Colorectal Cancer

“…While in the overall analysis of our population, the genotypes of rs1136201 were not associated with colorectal cancers, we observed a protective association with the G allele conferring 1.8-fold lower risk of developing the disease relative to the A allele. Similar to our findings, the genotypic analysis of rs1136201 in the Indian as well as Scottish Caucasian population did not show a significant correlation with colorectal carcinoma [ 17 , 18 ]. Interestingly, when our population were segregated based on gender, the rs1136201 demonstrated that women carriers of the AG genotype and the G allele were at 3.6-fold (OR = 0.275, p =0.02093) and 4.1-fold (OR = 0.244, p =0.00705) lower risk of colorectal malignancy relative to the AA genotype and A allele, respectively.…”

BCL-2 (-938C>A), BAX (-248G>A), and HER2 Ile655Val Polymorphisms and Breast Cancer Risk in Indian Population

“…Another meta-analysis study by Dahabreh and Murray also reported no association between HER2 Ile655Val polymorphism and breast cancer development which was based on 33 case-control studies including 20,461 cases and 23,832 controls [ 57 ]. Likewise, in a previous study from our group [ 58 ], we found no significant association of HER2 Ile655Val polymorphism with colorectal cancer in Indian population.…”