RT Journal Article
SR Electronic
T1 Laminin 5 γ2 chain expression: a marker of early invasiveness in colorectal adenomas
JF Molecular Pathology
JO Mol Pathol
FD BMJ Publishing Group Ltd and Association of Clinical Pathologists
SP 342
OP 346
DO 10.1136/mp.56.6.342
VO 56
IS 6
A1 C Lenander
A1 U J Roblick
A1 J K Habermann
A1 Å Öst
A1 K Tryggvason
A1 G Auer
YR 2003
UL http://mp.bmj.com/content/56/6/342.abstract
AB Aim: Polyps of the colon and rectum are considered to be premalignant lesions in the development of colorectal cancer. However, knowledge of how normal epithelial cells gain invasive properties is limited. Laminin 5 γ2 chain expression was investigated to determine the role of laminin 5 as a marker of potential invasiveness in colorectal polyps. Material/methods: Sixty seven polyps of different types (15 hyperplastic polyps, 12 serrated adenomas, 16 tubular adenomas, and 24 adenomas with a villous component) were assessed for γ2 chain expression of laminin 5 by immunohistochemistry on archival, paraffin wax embedded sections. Results: Ten polyps stained positive and the number of polyps expressing the laminin 5 γ2 chain increased significantly as the phenotype of the adenomas became more atypical: none of the 15 hyperplastic polyps, two of the 16 tubular adenomas (12.5%), and six of the 24 adenomas with a villous component (25%) were positive. Two of 12 (17%) serrated adenomas, regarded as a distinct form of colorectal neoplasia, showed γ2 chain expression. Furthermore, laminin 5 γ2 chain expression correlated with lesion size. Polyps smaller than 10 mm expressed the γ2 chain less frequently than did those equal to or larger than 10 mm. Conclusion: Laminin 5 γ2 chain expression was found to increase progressively towards a more atypical phenotype of adenoma. The results suggest that, in the future, laminin 5 γ2 chain expression may be used as an indicator of incipient malignant transformation of a benign colorectal adenoma.