Presence of neural cell adhesion molecule on human embryonic and brain tumours.

Development and maintenance of tissue organization in complex organisms has long been suspected to involve altered cell surface interactions between adjacent cells. Similarly, the process of tumour metastasis undoubtedly requires the expression of appropriate attachment sites for the embedding and subsequent proliferation of secondary turnours. Exciting developments in molecular cell biology are opening up new avenues for the study of both of these phenomena. The past few years have seen the identification of a whole array of glycoproteins which are involved in cell-ccll and cell-substrate adhesion. One of the best characterized cell adhesion molecules is the neural cell adhesion molecule (N-CAM) [ 11. We became interested in this glycoprotein when we showed that monoclonal antibody UJ13A [ 2 ] , an antibody which has found extensive use in cancer medicine. recognizes N-CAM. This has led t o the investigation of N-CAM expression in human embryonic and brain tumours to assess whether lack or abnormal expression contributes t o tumour pathology and metastasis. In addition, identification of specific N-CAM isoforms associated with various tumours may allow construction of appropriate probes for differential diagnosis of tumours. Here, we briefly outline the expression of N-CAM in normal tissues and review the available data on its expression in various tumours.