Expression of CD44, ICAM-1 and N-CAM in colorectal cancer. Correlation with the tumor stage and the phenotypical characteristics of tumor-infiltrating lymphocytes.

The cellular adhesion molecules (CAMs) CD44s, CD44v6, CD44v10, ICAM-1 and N-CAM were immunohistologically detected in colorectal cancers using the APAAP method. The expression of CD44s and CD44v6 was associated with the presence of lymph node metastases in the examined tumors. The pattern of ICAM-1 expression was inversely related to that of CD44, i.e. lower numbers of ICAM-1 positive cells were observed in metastasizing tumors. An intense focal staining of N-CAM was observed in the majority of the metastasizing tumors. The expression of CD44v, ICAM-1 or N-CAM on tumor cells did not correlate with the density of the tumor-infiltrating lymphocytes (TIL) within the tumors. The flowcytometric analysis of TIL showed a significant accumulation of CD25+ and HLA-DR+ cells and a reduced number of CD45RA+ cells as compared to autologous peripheral blood lymphocytes (PBL) or intraepithelial lymphocytes of the colon mucosa (IEL). These phenotypic characteristics of TIL did not correlate with the CAMexpression on tumor cells.