Establishment of Nasopharyngeal Carcinoma Cell Lines, Patient-Derived Xenografts, and Immortalized Nasopharyngeal Epithelial Cell Lines for Nasopharyngeal Carcinoma and Epstein–Barr Virus Infection Studies

Establishment of continuous cell lines and patient-derived xenografts (PDXs) remains a major challenge for nasopharyngeal carcinoma (NPC). All the reported NPC cell lines except one (C666-1) lost their Epstein–Barr virus (EBV) episomes upon long-term propagation. Furthermore, many commonly used NPC cell lines are contaminated with genetic elements of HeLa. By inclusion of a Rho kinase inhibitor (Y-27632) in the growth medium to suppress lytic reactivation of EBV, we have established two new NPC cell lines (C17 and NPC43) that retain EBV episomes. The low rate of NPC PDX establishment may reflect an NPC cell growth dependency on the tumor microenvironment. Nonetheless, we have established and characterized several new NPC PDXs for NPC investigation. Telomerase expression, in combination with the common genetic alterations present in NPC, efficiently immortalized primary cultures of nonmalignant nasopharyngeal epithelial cells. The lessons learnt from the establishment of these cell lines and NPC PDXs will be discussed.