Morphological transformation of nasopharyngeal epithelial cells in vitro by Epstein-Barr virus from B95-8 cells.

Tissue fragments of fresh biopsy specimens from the non-neoplastic NP mucosa of 20 subjects, from the tumours of 10 NPC patients, from the mucosa of freshly removed tonsils from nine subjects and from the primary lesions of seven patients with malignancies of the upper respiratory or alimentary tract other than NPC were infected with EBV derived from B95-8 cells. A significantly higher frequency of growth stimulation and a greater mean growth ratio between infected and uninfected fragments from the same source were observed in the non-neoplastic NP mucosa specimens than in the others. In addition, the growth characteristics and the morphology of the cells in the infected non-neoplastic NP mucosal explants resembled those of transformed cells; but whether they possess malignant potential is being investigated.