Association Of A SNP In MicroRNA Let-7 Complementary Region In KRAS 3'UTR With NSCLC

Lung cancer is the leading cause of cancer deaths worldwide. The let-7 family-of-microRNAs (miRNA) is global genetic regulators important in controlling lung cancer oncogene expression by binding to the 3'untranslated regions of their target mRNAs. The purpose of this study was to identify single nucleotide polymorphisms (SNP) that could modify let-7 binding and to assess the effect of such SNPs on target gene regulation and risk for non–small cell lung cancer (NSCLC).The study population consisted of 83 patients with NSCLC, 80 healthy controls from the southeast of China and five NSCLS cells (A549, SPC, 95D, LTEP and NCI-H460). Only one single nucleotide polymorphism (SNP), rs712 in LCS1, was selected across Let-7 microRNA Complementary Site in the KRAS 3'UTR using miRBase datas and HapMap II datas. The SNP was amplified by polymerase chain reaction (PCR) and genotyped by restriction enzyme digestion followed by gelelectrophoresis. Logistic regression was performed to assess odds ratios (OR) and 95% confidence intervals (CI), which were adjusted for gender and age.Our results suggested that 1. No distribution difference of rs712 between NSCLC cases and controls was observed. 2. The genetypes of rs712 in A549, SPC, 95D, LTEP and NCI-H460 are all GG. 3. Genotype and allelic frequeNCI460es of rs712 among NSCLC cases in different stages were no distribution difference, so were between AC and SCC.The study indicated that the rs712 is no significantly associated with increased risk for NSCLC among case and control. Whether the SNP in LCS becomes genetic markers of lung cancer risk useful for screening exist still needs further studies.