December 1991

Carbohydrate-Binding Protein 35 Is the Major Cell-Surface Laminin-Binding Protein in Colon Carcinoma

Author Affiliations

From the Laboratory of Cancer Biology, Deaconess Hospital, Harvard Medical School, Boston, Mass.

Arch Surg. 1991;126(12):1498-1502. doi:10.1001/archsurg.1991.01410360072011

• The interaction of tumor cells with laminin is thought to be critical in invasion and metastasis. We found that an endogenous lectin, carbohydrate-binding protein 35 (CBP-35), is the major laminin-binding protein on human colon carcinoma cells and that its surface expression suggests involvement in metastasis. We identified CBP-35 by lamininaffinity chromatography and immunoblotting. Surface expression of CBP-35 on eight human colon carcinoma cell lines was compared by flow cytometry. Poorly differentiated cell lines and DLD-2, a signet-ring carcinoma cell line, expressed more surface CBP-35 than well-differentiated cell lines. Poorly differentiated cell lines and DLD-2 are characterized as aggressive cell lines because they adhere to and invade through reconstituted basement membrane significantly better than well-differentiated cell lines. These data suggest that CBP-35 is involved in tumor cell-basement membrane interactions and that an increase in CBP-35 surface expression may facilitate metastatic potential of colon carcinoma cells.

(Arch Surg. 1991;126:1498-1502)