Establishment of a new EBV-positive NPC cell line, NPC268 from a non-keratinizing differentiated NPC primary tumor. A, H&E staining revealed NPC268 tumor as the non-keratinizing, differentiated NPC subtype. Scale bar: 100 µm. B, Epithelial origin was confirmed using pan-cytokeratin staining. Scale bar: 100 µm. C, EBER expression marked the EBV positivity in NPC268. Scale bar: 100 µm. D, LCA/CD45 staining reveals tumor-infiltrating lymphocytes in NPC268. Scale bar: 100 µm. E, Images of NPC268 cell line taken at passage 0, 20, and 100, respectively. Scale bar: 100 µm. F, Growth curve of NPC268 cell line, which has been cultured for >100 passages with no sign of senescence. G, Representative karyotype profile of the NPC268 cell line (at passage 108) revealed metaphases of hypotetraploidy with complex structural abnormalities.
ARTICLE ABSTRACT
Nasopharyngeal carcinoma (NPC), a cancer that is etiologically associated with the Epstein-Barr virus (EBV), is endemic in Southern China and Southeast Asia. The scarcity of representative NPC cell lines owing to the frequent loss of EBV episomes following prolonged propagation and compromised authenticity of previous models underscores the critical need for new EBV-positive NPC models. Herein, we describe the establishment of a new EBV-positive NPC cell line, designated NPC268 from a primary non-keratinizing, differentiated NPC tissue. NPC268 can undergo productive lytic reactivation of EBV and is highly tumorigenic in immunodeficient mice. Whole-genome sequencing revealed close similarities with the tissue of origin, including large chromosomal rearrangements, while whole-genome bisulfite sequencing and RNA sequencing demonstrated a hypomethylated genome and enrichment in immune-related pathways, respectively. Drug screening of NPC268 together with six other NPC cell lines using 339 compounds, representing the largest high-throughput drug testing in NPC, revealed biomarkers associated with specific drug classes. NPC268 represents the first and only available EBV-positive non-keratinizing differentiated NPC model, and extensive genomic, methylomic, transcriptomic, and drug response data should facilitate research in EBV and NPC, where current models are limited.
NPC268 is the first and only EBV-positive cell line derived from a primary non-keratinizing, differentiated nasopharyngeal carcinoma, an understudied but important subtype in Southeast Asian countries. This model adds to the limited number of authentic EBV-positive lines globally that will facilitate mechanistic studies and drug development for NPC.
