POLYSIALYLATED N-CAM, CHROMOGRANIN-A AND CHROMOGRANIN-B, AND SECRETOGRANIN-II IN NEUROENDOCRINE TUMORS OF THE LUNG

Highly alpha 2-8-sialylated N-CAM (neural cell adhesion molecule) impa irs N-CAM-mediated cell adhesion. We investigated polysiaN-CAM immunor eactivity in a range of neuroendocrine lung tumours: 15 typical carcin oids, 21 atypical carcinoids, 2 large cell neuroendocrine carcinomas a nd 13, small cell lung carcinomas were selected on a morphological bas is and by their immunoreactivity for chromogranin A and B and secretog ranin II. A progressive loss of chromogranin expression, particularly of chromogranin B, was paralleled by the up-regulation of polysiaN-CAM in histologically more aggressive rumours (P = 0.001). These data sup port the hypothesis that loss of cell-cell adhesion properties might b e a relevant factor in the origin of the aggressivity of lung neuroend ocrine rumours.