Differential expression of high molecular weight caldesmon in colorectal pericryptal fibroblasts and tumour stroma

Abstract

Aim - To investigate an extent of smooth muscle differentiation of pericryptal fibroblasts. Methods - Expression of high molecular weight caldesmon (h-CD) and α smooth muscle actin was investigated in 123 invasive colorectal adenocarcinomas and their surrounding non-neoplastic tissues. Results - The monoclonal antibody to h-CD, which showed predominantly positive immunostaining in well differentiated smooth muscle cells, recognised pericryptal fibroblasts, smooth muscle cells, and pericytes, but was not reactive to myofibroblasts. Antibody to α smooth muscle actin recognised not only pericryptal fibroblasts, smooth muscle cells, and pericytes but also myofibroblasts. Conclusions - Pericryptal fibroblasts show greater smooth muscle differentiation than myofibroblasts and there is a posibility that they are well differentiated smooth muscle cells; h-CD is an excellent marker to discriminate pericryptal fibroblasts from myofibroblasts.