Application of high resolution melting technique for detection of germ line single nucleotide polymorphisms in STK11 gene among patients with various gastrointestinal cancers

High Resolution Melting (HRM) is a method that analyzes genetic variations such as Single Nucleotide Polymorphisms (SNPs) in PCR amplicons. The STK11 gene encodes a member of the serine/threonine kinase and regulates cell polarity and function as a tumor suppressor gene. The germ-line mutations in this gene are associated with Peutz-Jeghers syndrome. The patients with this syndrome are prone to some types of neoplasm.

In this experimental study, genomic DNA was extracted from the whole blood samples of 56 patients with various gastrointestinal cancers. The nucleotide changes in the entire STK11 gene were analyzed by Real-time PCR and H RM technique.

The nucleotide screening by HRM technique showed two types of SNPs in introns 6 and 7 of STK11 gene in 10 patients. Four patients had C / T substitution [cluster id/dsSNP/rs9282860] with homozygous genotype in intron 6, and six patients showed a C/G substitution [cluster id/dsSNP/rs2075607] with heterozygous genotype in intron 7. The direct sequencing of the fragments confirmed that the results obtained by HRM were 100% reliable.

In this study we found no SNP in exons of STK11 gene. However, two SNPs were found in the introns of this gene. Our results show that the primary screening of the STK11gene by the HRM technique is easily applicable to detect the unknown germ line and somatic mutations in patients with neoplasia at a relatively low cost.