Non-malignant epithelial cells preferentially proliferate from nasopharyngeal carcinoma biopsy cultured under conditionally reprogrammed conditions

Fenggang Yu,Hironori Yoshiyama,De-Chen Lin,Kwok Seng Loh,Phillip H Koeffler,Lingzhi Wang,Yanan Lu,Boon-Cher Goh,Fredrik Petersson,Yan-Yi Jiang,Lin Tao

doi:10.1038/s41598-017-17628-z

Abstract

Nasopharyngeal carcinoma (NPC) is an invasive cancer with particularly high incidence in Southern China and Southeast Asia. The study of NPC is greatly hampered by the lack of reliable cell lines due to the loss of EBV genome and HeLa cell contamination. Conditional reprogramming (CR) cell culture technique has been reported for rapid and efficient establishment of patient‐derived normal and tumor cell cultures. The purpose of this study was to assess this method to culture NPC patient‐derived primary tumor cells. Using CR protocol, we demonstrated that epithelial cells could be efficiently cultured from normal (70%) and cancerous nasopharyngeal (46%) biopsies. However, by comparing with original tumors in terms of mutation and methylation profiles, epithelial cells derived from cancerous biopsy represented non‐malignant cells. Further, they exhibited stem‐like characteristics based on their cell surface proteins and could differentiate into pseudostratified epithelium in an air–liquid interface culture system. We conclude that CR method is a highly selective and useful method for growing non‐malignant nasopharyngeal epithelial cells.

Highlights

Nasopharyngeal carcinoma (NPC) is a common cancer in endemic regions such as Southern China and South East Asia[1]
The FG014 biopsy had more than 90% of EBER-ISH cells among pan Cytokeratin (pan-CK) positive cells, consistent with the majority of epithelial cells of this sample were tumor cells (Fig. 4A and B)
When real time Polymerase chain reaction (PCR) of EBNA1 was used to track tumor cells, EBNA1 Initially was detected in cell culture, but it diminished very quickly

Summary

Introduction

Nasopharyngeal carcinoma (NPC) is a common cancer in endemic regions such as Southern China and South East Asia[1]. Immortalized cancer cell lines and xenografts have been used widely for the study of NPC tumor biology and testing of new therapies. Widespread HeLa cell contamination has been documented in many NPC cell lines[5]. Liu et al reported a “conditionally reprogramed cells” method of culturing both normal and tumor epithelial cells It uses a Rho kinase inhibitor (ROCKi) Y-27632 and irradiated mouse 3T3 fibroblast feeder cells[6]. If this method is applicable to NPC, it would represent a significant technical advancement in the establishment of primary tumor cultures from limited patient biopsy specimens. The aim of this study was to assess this method of establishing primay tumor cell cultures from NPC biopsy

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Methods

Results

Conclusion