A study of cell membrane structure.

Neoplastic transformation has been associated with a variety of structural changes, among which are changes in membrane carbohydrates. Not much is known, though, e.g., how early in the tumourogenic event these changes take place and what effect these changes have on cell growth, invasion, and ability to metastasize. We were able to identify the B-D-Gal(1-3)DGal-NAc as a membrane carbohydrate component present in malignant laryngeal tissue, but not on adjacent normal mucous membrane. This carbohydrate structure was found to be present in metastatic as well as in nonmetastatic tumours. It was also found in well-differentiated as well as poorly differentiated carcinomas. We suggest that changes in carbohydrate components on the cell membrane of the laryngeal cancer cell are an early event in tumour progression and probably are not related to the degree of invasion or the ability to metastasize.