Publications Search

Search for publications by author
Search for publications by abstract keyword(s)

Tetranucleotide and Low Microsatellite Instability Are Inversely Associated with the CpG Island Methylator Phenotype in Colorectal Cancer


MSH3 gene or protein deficiency or loss-of-function in colorectal cancer can cause a DNA mismatch repair defect known as "elevated microsatellite alterations at selected tetranucleotide repeats" (EMAST). A high percentage of MSI-H tumors exhibit EMAST, while MSI-L is also linked with EMAST. However, the distribution of CpG island methylator phenotype (CIMP) within the EMAST spectrum is not known. Five tetranucleotide repeat and five MSI markers were used to classify 100 sporadic colorectal tumours for EMAST, MSI-H and MSI-L according to the number of unstable markers detected. Promoter methylation was determined using methylation-specific PCR for MSH3, MCC, CDKN2A (p16) and five CIMP marker genes. EMAST was found in 55% of sporadic colorectal carcinomas. Carcinomas with only one positive marker (EMAST-1/5, 26%) were associated with advanced tumour stage, increased lymph node metastasis, MSI-L and lack of CIMP-H. EMAST-2/5 (16%) carcinomas displayed some methylation but MSI was rare. Carcinomas with >/=3 positive EMAST markers (13%) were more likely to have a proximal colon location and be MSI-H and CIMP-H. Our study suggests that EMAST/MSI-L is a valuable prognostic and predictive marker for colorectal carcinomas that do not display the high methylation phenotype CIMP-H.

Type Journal
ISBN 2072-6694 (Print) 2072-6694 (Linking)
Authors Meessen, S.; Currey, N.; Jahan, Z.; Parker, H. W.; Jenkins, M. A.; Buchanan, D. D.; Hopper, J. L.; Segelov, E.; Dahlstrom, J. E.; Kohonen-Corish, M. R. J.
Publisher Name Cancers
Published Date 2021-07-31
Published Volume 13
Published Issue 14
Status Published in-print
DOI 10.3390/cancers13143529
URL link to publisher's version