Immunofluorescence and electron microscopic investigations of epithelial hybrid cells derived from nasopharyngeal carcinoma (NPC-KT).

The present study was made to investigate some characteristics of the epithelial hybrid cells derived from nasopharyngeal carcinoma (NPC-KT cells) both in vivo and in vitro, using immunofluorescence and electron microscopic techniques. Immunofluorescence and electron microscopic studies have shown that the appearance of Epstein-Barr virus (EBV)-related early antigens, EB-viral capsid antigens and virus particles in nude-mouse-grown-tumour cells were rather repressed, in contrast to, in vitro culture of the NPC-KT cells. The tumours after transplantation of the NPC-KT cells to nude mice showed pathological pictures of poorly differentiated carcinoma with EBV-associated nuclear antigen and derived from the NPC-KT cells by means of cytogenetic studies. More importantly, we have detected EBV-related membrane antigens (MA) on the epithelial NPC-KT cells. To our knowledge, the presence of MA on the malignant epithelial cells of the nasopharynx have never been demonstrated. The results reported here show for the first time the presence of MA on nasopharyngeal carcinoma cells.