Establishment and characterization of three transplantable EBV‐containing nasopharyngeal carcinomas

Abstract

Three transplantable nasopharyngeal carcinoma (NPC) tumors, designated C15, C17 and C18, have been obtained and characterized. C15, derived from a primary NPC tumor, has been propagated in nude mice for 30 passages. C17 and C18, derived from metastatic NPC tissue, have been passaged 10 times. Desmosomes, present in every case, provided confirmation of the epithelial origin of all 3 tumors. The Epstein-Barr virus (EBV) genome is contained in C15, C18 and C17 tumor cells with 30, 12 and 3 copies, respectively. The Epstein-Barr virus nuclear antigen (EBNA) was stained by the classical anti-complement immunofluorescence (ACIF) technique. Fluorescence intensity was strong in C15, moderate in C18, and hardly detectable in C17 cells. No expression of the EA and VCA antigens was detected. Flow cytometry analysis performed on monocellular suspensions showed the absence of detectable CR2 molecules (the EBV receptor on B lymphocytes) in all 3 tumors, and the constitutive expression of HLA class-II antigens in C15 and C17 cells. IL-1 activity was demonstrated in the supernatant of C15 and C17 cells cultivated in vitro for 3 days. These data confirm that the constitutive synthesis of MHC class-II molecules and the release of IL-1-like activities are frequent features of NPC cells. These characteristics could be of importance in relation with the T-cell infiltrate found in NPC primary tumors.

Infection of Epstein–Barr virus in a gastric carcinoma cell line induces anchorage independence and global changes in gene expression

“…Growth in soft agar was assessed by resuspending cells in 2 mL of media containing 0.5% bactoagar in a six-well plate. After agar solidified, an additional 4 mL of F-12 media was added to the top and the plate was allowed to grow for 12 d, changing the media every 2 d. The NPC xenograft tumors C15, C17, and C18 were serially passaged in nude mice and have been described previously (36).…”

Targeted depletion of BMI1 sensitizes tumor cells to P53-mediated apoptosis in response to radiation therapy

“…C15 and C17 NP xenograft tumors were passaged in vivo, as described previously. 35 UT-SCC-8 cells were grown in DME H21 medium supplemented with 10% fetal bovine serum, 100 mg/l penicillin, and 100 mg/l streptomycin (RPMI-10) at 371C 5% CO 2. BMI1 SMARTpool (siBMI1), 9 and P53 SMARTpool (siP53) were purchased from Dharmacon (Dharmacon Inc., Lafayette, CO, USA).…”

The major 8p22 tumor suppressor DLC1 is frequently silenced by methylation in both endemic and sporadic nasopharyngeal, esophageal, and cervical carcinomas, and inhibits tumor cell colony formation

“…We also collected four sporadic Caucasian NPC from the Department of Otolaryngology-Head and Neck Surgery, John Hopkins Hospital, Baltimore, which together with three nude mice-passaged undifferentiated NPC tumors derived from North Africans (C15, C17, C18) (Busson et al, 1988), acted as comparison for the endemic type NPC from Southern China and Southeast Asia. A total of 94 esophageal carcinomas of squamous cell carcinoma type from Hong Kong Chinese and their corresponding surgical marginal tissues and eight normal esophageal tissues from healthy individuals (Wong et al, 2006) …”