Neoplastic cell apoptosis in nude mice transplants with nasopharyngeal carcinoma cell lines

Abstract

Objective: To observe the morphological features of neoplastic cell apoptosis developed in nude mice transplants with nasopharyngeal carcinoma (NPC) cell lines, CNE-1 and CNE-2, and to investigate the roles of p53, bcl-2 and bax playing in the process of apoptosis. Methods: CNE-1 and CNE-2 cell lines were inoculated and passed in nude mice for 3 generations. The cell apoptosis was detected on H & E and TUNEL staining slides. The expression of p53, bcl-2 and bax were detected by using immunohistochemistry. p53 gene alteration was assayed in cell lines and transplants by PCR-SSCP. Results: A considerable number of neoplastic cells underwent apoptosis in CNE-1 and CNE-2 transplant tissues. The “shrinkage necrosis” and apoptotic bodies were the main appearances of apoptosis. The p53 alteration was detected in exon 8 by PCR-SSCP and p53 protein accumulation observed in the cell smears and nude mice transplant tissue sections. All the transplant tissue sections of 3 passages showed bcl-2 negativity and bax overexpression. Conclusion: The neoplastic cells of CNE-1 and CNE-2 transplants underwent death mainly taking the way of apoptosis. The “shrinkage necrosis” and apoptotic bodies were the main morphological features of apoptosis seen in those transplants. The apoptosis in CNE-1 or CNE-2 nude mice transplant is highly probable through a p53-independent and bax-mediated pathway.