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Major improvement in the detection of microsatellite instability in colorectal cancer using HSP110 T17 E‐ ice ‐COLD‐PCR
Author(s) -
HowKit Alexandre,
Daunay Antoine,
Buhard Olivier,
Meiller Clément,
Sahbatou Mourad,
Collura Ada,
Duval Alex,
Deleuze JeanFrançois
Publication year - 2018
Publication title -
human mutation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 162
eISSN - 1098-1004
pISSN - 1059-7794
DOI - 10.1002/humu.23379
Subject(s) - microsatellite instability , biology , microsatellite , microbiology and biotechnology , colorectal cancer , lynch syndrome , cold pcr , dna , genotype , cancer , polymerase chain reaction , dna mismatch repair , genetics , mutation , allele , gene , point mutation
Abstract Every colorectal cancer (CRC) patient should be tested for microsatellite instability (MSI) to screen for Lynch syndrome. Evaluation of MSI status involves screening tumor DNA for the presence of somatic deletions in DNA repeats using PCR followed by fragment analysis. While this method may lack sensitivity due to the presence of a high level of germline DNA, which frequently contaminates the core of primary colon tumors, no other method developed to date is capable of modifying the standard PCR protocol to achieve improvement of MSI detection. Here, we describe a new approach developed for the ultra‐sensitive detection of MSI in CRC based on E‐ ice ‐COLD‐PCR, using HSP110 T17, a mononucleotide DNA repeat previously proposed as an optimal marker to detect MSI in tumor DNA, and an oligo(dT) 16 LNA blocker probe complementary to wild‐type genotypes. The HT17 E‐ ice ‐COLD‐PCR assay improved MSI detection by 20–200‐fold compared with standard PCR using HT17 alone. It presents an analytical sensitivity of 0.1%–0.05% of mutant alleles in wild‐type background, thus greatly improving MSI detection in CRC samples highly contaminated with normal DNA. HT17 E‐ ice ‐COLD‐PCR is a rapid, cost‐effective, easy‐to‐implement, and highly sensitive method, which could significantly improve the detection of MSI in routine clinical testing.