title: Tissue microarray technology: validation in colorectal carcinoma and analysis of p53, hMLH1, and hMSH2 immunohistochemical expression.
abstract: Tissue microarray technology enables the analysis of hundreds of specimens by arranging numerous 0.6-mm tissue core biopsy specimens into a single paraffin block. Validation studies are necessary to evaluate the representativeness of small disks taken from the original tissue. We validated the tissue microarray technology in colorectal carcinoma by analyzing the immunohistochemical expression of proteins involved in the two main pathways of colorectal carcinogenesis: p53 protein for loss of heterozygosity tumors, hMLH1 and hMSH2 proteins for microsatellite instability (MSI) tumors. We compared in 30 colorectal carcinomas (15 MSI(-) and 15 MSI(+)), 8 microarrays disks, and the whole section of the block from which they were derived. Tumoral tissue was present in 95.7% of the microarray disks. The analysis of three disks per case was comparable to the analysis of the whole section in 99.6% (p53), 98.8% (hMLH1), and 99.2% (hMSH2) of cases. In the second part we applied the tissue microarray technology to 263 consecutive cases of colorectal carcinoma, sampled by three cores. We showed that 48.5% overexpressed p53 and 8.7% lost hMLH1 or hMSH2. Tissue microarray technology, validated in colorectal carcinoma, appears as a useful research tool for rapid analysis of the clinical interest of molecular alterations.
authors.affiliation: Department of Pathology, Hôpital Saint-Antoine, 184 rue du Faubourg Saint-Antoine, 75012 Paris, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Jourdan
authors.forename: Nicole
authors.initials: N
authors.lastname: Sebbagh
authors.forename: Eva
authors.initials: E
authors.lastname: Comperat
authors.forename: Najat
authors.initials: N
authors.lastname: Mourra
authors.forename: Antoine
authors.initials: A
authors.lastname: Flahault
authors.forename: Sylviane
authors.initials: S
authors.lastname: Olschwang
authors.forename: Alex
authors.initials: A
authors.lastname: Duval
authors.forename: Richard
authors.initials: R
authors.lastname: Hamelin
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Flejou
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000230:Adenocarcinoma / Q000737:chemistry* / Q000473:pathology; D014408:Biomarkers, Tumor / Q000032:analysis; D002352:Carrier Proteins; D015179:Colorectal Neoplasms / Q000737:chemistry* / Q000473:pathology; D004268:DNA-Binding Proteins; D005260:Female; D016591:Histocytological Preparation Techniques; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein; D009363:Neoplasm Proteins / Q000032:analysis*; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins / Q000032:analysis*; D016159:Tumor Suppressor Protein p53 / Q000032:analysis*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D014408:Biomarkers, Tumor; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; C501486:MLH1 protein, human; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D016159:Tumor Suppressor Protein p53; C497172:MSH2 protein, human; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein