Frequent loss of SMAD4/DPC4 protein in colorectal cancers. Issue 6 (1st December 2002)

• Record Type: Journal Article
• Authors: Salovaara, R; Roth, S; Loukola, A; Launonen, V; Sistonen, P; Avizienyte, E; Kristo, P; Järvinen, H; Souchelnytskyi, S; Sarlomo-Rikala, M; Aaltonen, L A
• Is Part Of: Journal of clinical pathology. Volume 55:Issue 6(2002)
• Page Start: 385
• Page End: 388
• Publication Date: 2002-12-01
• Subjects: SMAD4 -- DPC4 -- colorectal carcinoma -- immunohistochemistry; MSI, microsatellite instability -- LOH, loss of heterozygosity -- RT-PCR, reverse transcription-polymerase chain reaction -- TGF-βIIR, transforming growth factor β type II receptor; Pathology -- Periodicals; Pathology, Molecular -- Periodicals; 616.0705
• DOI: 10.1136/mp.55.6.385
• Languages: English
• ISSNs: 0021-9746

Abstract

Abstract : Background and aims: Loss of DNA sequences from chromosome 18q21 is a major genetic change in colorectal tumorigenesis. Multiple genes have been identified in this area. One of these, DPC4 ( deleted in pancreatic cancer 4, also known as SMAD4 ), is mutated in a minor subset of colorectal carcinomas as well as in germlines of humans predisposed to colon tumours. Patients and methods: The involvement of SMAD4 in sporadic colorectal neoplasia was evaluated by immunohistochemistry in 53 unselected cases and 27 cases displaying microsatellite instability. Results: SMAD4 expression was absent in 20 of 53 (38%) unselected colorectal carcinomas, and reduced in another 15 (28%) cases. However, 26 of 27 cancers displaying microsatellite instability and TGF-βIIR mutations were positive for SMAD4 immunostaining. Conclusions: Loss of SMAD4 expression may play a more prominent role in colon cancer than anticipated based on genetic evidence, but not in mutator phenotype tumours.