EXPRESSION OF ADHESION MOLECULES IN THE HOST RESPONSE TO COLON-CARCINOMA

Expression of the adhesion molecules LFA-1, ICAM-1, and VCAM-1 was stu died in five resected colon carcinomas, one villous adenoma, and norma l colon mucosa to determine whether expression of these markers is inc reased in response to tumor. Frozen tissue samples were stained by a l abeled avidin-biotin technique using primary antibodies to LFA-1 (CD11 a), CD2, CD4, CD8, CD20, CD68, HLA-DR, ICAM-1 (CD54), and VCAM-1. For each marker, the number of positive mononuclear cells was graded semiq uantitatively, and stromal and endothelial cells were scored as either positive or negative. Overall grade of inflammation was increased in tumor compared with normal mucosa in five cases. Cells positive for LF A-1, CD2, CD4, CD8, and CD20 were increased in the tumors in the same cases. ICAM-1 was expressed in vessels, inflammatory cells, and stroma l cells in normal mucosa. It was markedly increased in tumor stroma in all six cases. VCAM-1 was negative in normal mucosa, and focally expr essed in tumor vessels and stroma. We conclude that increased expressi on of adhesion molecules occurs around colon neoplasms, particularly i n stroma[ cells, and may be a mechanism for the recruitment of activat ed leukocytes as part of the inflammatory response to colon carcinomas .