Optimization of high resolution melting (HRM) method for genotyping and estimating the frequency of SNPRs4283405 on microrna 17-92 cluster ost gene in the vietnamese breast cancer patients.

Abstract

Breast cancer is one of the most common and dangerous disease among women throughout the world whose incidence continues to increase rapidly, particularly in several Asian countries. Two main factors impact on this malignance including: extrinsic elements mostly from the environment such as: age, weight, personal lifestyle, etc. and intrinsic ones which are genetic disorder, or family inheritance. Numerous studies have reported that genetic disorder is the main reason leading to breast cancer exposure. Among well – known causative breast cancer genes like: BRCA1/2, PTEN, p53…, microRNAs (miRNAs), recently, have been proven to play a critical role in breast cancer development and can serve as a new potential biomarker for breast cancer detection. SNP rs4284505 located on miRNA 17 – 92 cluster host gene exhibit the strong association with breast cancer in Caucasian Australian. Therefore, in this study, SNP rs4284505 is investigated to determine whether it can relate to breast cancer in Vietnamese patients. High Resolution Melting (HRM) method has been optimized to screen selected SNP, aiming at predicting the correlation of the chosen SNP and breast cancer in Vietnam. The total of 100 breast cancer samples were collected from Oncology hospital and would be compared with 101 healthy samples whose data was obtained from 1000 Genome Database. The result showed that, the optimal HRM protocol was constructed with high sensitivity (up to 95%), specificity and stability. The polymorphism rs4284505 does occur in Vietnamese population with the frequencies of two alleles G and A being 44.27% and 55.73%, respectively. And the presence of G allele seems likely to have the protective effect on susceptibility to breast cancer because OR was less than 1 [OR (95%CI) = 0.80 (0.54–1.18)]. Nevertheless, because the p-value is greater than threshold (>0.05) in all genetic models, this SNP does not associate with breast cancer risk. Also, the power of the study was too low, only 11.82% due to small population size. Hence, a further research should be conducted in a larger scale to validate the relationship between SNP rs4284505 and breast cancer in Vietnam. Keywords: Breast cancer SNP rs4284505 High Resolution Melting (HRM)