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MUC5 AC hypomethylation is a predictor of microsatellite instability independently of clinical factors associated with colorectal cancer
Author(s) -
Renaud Florence,
Vincent Audrey,
Mariette Christophe,
Crépin Michel,
Stechly Laurence,
Truant Stéphanie,
Copin MarieChristine,
Porchet Nicole,
Leteurtre Emmanuelle,
Van Seuningen Isabelle,
Buisine MariePierre
Publication year - 2014
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.29342
Subject(s) - microsatellite instability , colorectal cancer , dna methylation , methylation , kras , cpg site , mucin 2 , biology , mucin , cancer , biomarker , cancer research , medicine , oncology , allele , genetics , microsatellite , gene , gene expression , biochemistry
Colorectal cancers (CRC) with microsatellite instability (MSI) display unique clinicopathologic features including a mucinous pattern with frequent expression of the secreted mucins MUC2 and MUC5AC. The mechanisms responsible for this altered pattern of expression remain largely unknown. We quantified DNA methylation of mucin genes ( MUC2 , MUC5AC , MUC4 ) in colonic cancers and examined the association with clinicopathological characteristics and molecular (MSI, KRAS , BRAF, and TP53 mutations) features. A control cohort was used for validation. We detected frequent hypomethylation of MUC2 and MUC5AC in CRC. MUC2 and MUC5AC hypomethylation was associated with MUC2 and MUC5AC protein expression ( p = 0.004 and p < 0.001, respectively), poor differentiation ( p = 0.001 and p = 0.007, respectively) and MSI status ( p < 0.01 and p < 0.001, respectively). Interestingly, MUC5AC hypomethylation was specific to MSI cancers. Moreover, it was significantly associated with BRAF mutation and CpG island methylator phenotype ( p < 0.001 and p < 0.001, respectively). All these results were confirmed in the control cohort. In the multivariate analysis, MUC5AC hypomethylation was a highly predictive biomarker for MSI cancers. MUC5AC demethylation appears to be a hallmark of MSI in CRC. Determination of MUC5AC methylation status may be useful for understanding and predicting the natural history of CRC.