Diagnostic utility of MS-MLPA in DNA methylation profiling of adenocarcinomas and neuroendocrine carcinomas of the colon-rectum.

Abstract

Methylation-specific multiple ligation-dependent probe amplification (MS-MLPA) is a fast, new, inexpensive method that has rarely been exploited in DNA methylation profiling of colorectal cancers (CRCs). The aim of this study was to test the diagnostic utility of MS-MLPA to evaluate the methylation status of 34 genes in normal colonic mucosa samples and in a well-characterized series of 83 adenocarcinomas and 21 neuroendocrine carcinomas of colon-rectum. Two commercial MS-MLPA kits (SALSA MS-MLPA ME001-C1 Tumor suppressor-1 Kit and SALSA MS-MLPA ME002-B1 Tumor suppressor-2 Kit) were used to perform promoter methylation analysis on formalin-fixed and paraffin-embedded tissues. MS-MLPA analysis was validated by bisulfite pyrosequencing, bisulfite cycle sequencing, and methylation-specific PCR. MS-MLPA analysis identified a subset of 27 CRCs (26 % of cases) showing high levels of gene methylation involving a mean percentage of 34 % of the promoters examined. These tumors exhibited all the main clinicopathological and genetic features described for CRCs with CpG island Methylator Phenotype-High. High levels of methylation were observed with similar frequency in adenocarcinomas and in neuroendocrine carcinomas (25 % versus 29 %, respectively), but different methylation profiles were observed in the two tumor types. In both groups, tumors with microsatellite instability and widespread methylation represented a homogeneous clinicopathological entity. MS-MLPA assay is an easy and reliable system for epigenetic characterization of tumor tissues and leads to a rapid identification of CRCs with the highest levels of gene methylation. Aberrant gene methylation is a common abnormality in CRC initiation and may be observed in tumors with very different genetic and clinicopathological profiles.

• Authors: Daniela Furlan, Nora Sahnane, Mara Mazzoni, Roberta Pastorino, Ileana Carnevali, Michele Stefanoli, Andrea Ferretti, Anna Maria Chiaravalli, Stefano La Rosa, Carlo Capella
• Journal: Virchows Archiv : an international journal of pathology (Virchows Arch) Vol. 462 Issue 1 Pg. 47-56 (Jan 2013) ISSN: 1432-2307 [Electronic] Germany
• PMID: 23224118 (Publication Type: Journal Article)

Chemical References

• DNA, Neoplasm
• Tumor Suppressor Proteins

Topics

• Adenocarcinoma (diagnosis, genetics)
• Adult
• Aged
• Aged, 80 and over
• Carcinoma, Neuroendocrine (diagnosis, genetics)
• Colorectal Neoplasms (diagnosis, genetics)
• CpG Islands (genetics)
• DNA Methylation
• DNA, Neoplasm (genetics)
• Female
• Gene Expression Profiling
• Humans
• Male
• Middle Aged
• Neoplasm Staging
• Nucleic Acid Amplification Techniques
• Oligonucleotide Array Sequence Analysis
• Tumor Suppressor Proteins (genetics)