Genetic progression in microsatellite instability high (MSI-H) colon cancers correlates with clinico-pathological parameters: A study of the TGRbetaRII, BAX, hMSH3, hMSH6, IGFIIR and BLM genes

Int J Cancer. 2000 May 20;89(3):230-5.


Colon carcinomas with microsatellite mutator phenotype exhibit specific genetic and clinico-pathological features. This report describes the analysis of 63 "microsatellite instability-high" (MSI-H) tumors for the presence of mutations in microsatellites located in the coding regions (CDRs) of 6 genes: TGFbetaRII, BAX, hMSH3, hMSH6, IGFIIR, and BLM. The following frequencies of mutations were detected: TGFbetaRII (70%), BAX (54%), hMSH3 (36.5%), IGFIIR (22%), hMSH6 (17.5%), and BLM (16%). The overall picture revealed combinations of mutations suggestive of a progressive order of accumulation, with mutations of TGFbetaRII and BAX first, followed by frameshifts in hMSH3, hMSH6, IGFIIR, and BLM. Correlations with 12 clinico-pathological parameters revealed that tumors with frameshifts in 1 or 2 CDRs were significantly better differentiated than tumors with frameshifts in more than 2 CDRs. We also found that mutations in the hMSH3 gene were significantly associated with decreased wall invasiveness and aneuploidy, and frameshifts in the BLM gene were significantly associated with the mucinous histotype. A trend toward an association between hMSH3 and IGFIIR with the medullary and conventional adenocarcinoma histotypes, respectively, was seen. Our results strengthen the concept that mutations in target genes have a role in the tumorigenic process of MSI-H tumors, and indicate that frameshifts in microsatellites located in CDRs occur in a limited number of combinations that could determine distinct clinico-pathological traits.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / genetics*
  • Cell Differentiation / genetics
  • Colonic Neoplasms / genetics*
  • DNA Helicases / genetics*
  • DNA-Binding Proteins / genetics*
  • Disease Progression*
  • Female
  • Flow Cytometry
  • Frameshift Mutation
  • Humans
  • Male
  • Microsatellite Repeats / genetics*
  • Middle Aged
  • Multidrug Resistance-Associated Proteins*
  • MutS Homolog 3 Protein
  • Ploidies
  • Protein Serine-Threonine Kinases
  • Proto-Oncogene Proteins / genetics*
  • Proto-Oncogene Proteins c-bcl-2*
  • RecQ Helicases
  • Receptor, IGF Type 2 / genetics*
  • Receptor, Transforming Growth Factor-beta Type II
  • Receptors, Transforming Growth Factor beta / genetics*
  • bcl-2-Associated X Protein


  • BAX protein, human
  • DNA-Binding Proteins
  • G-T mismatch-binding protein
  • MSH3 protein, human
  • Multidrug Resistance-Associated Proteins
  • MutS Homolog 3 Protein
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • Receptor, IGF Type 2
  • Receptors, Transforming Growth Factor beta
  • bcl-2-Associated X Protein
  • Protein Serine-Threonine Kinases
  • Receptor, Transforming Growth Factor-beta Type II
  • Adenosine Triphosphatases
  • Bloom syndrome protein
  • DNA Helicases
  • RecQ Helicases
  • multidrug resistance-associated protein 1