Association of Plasma Epstein-Barr Virus LMP1 and EBER1 with Circulating Tumor Cells and the Metastasis of Nasopharyngeal Carcinoma.

Epstein-Barr virus (EBV) has been widely recognized to contribute to the development of nasopharyngeal carcinoma (NPC). The present study was to explore the association of plasma Epstein-Barr Virus LMP1 and EBER1 with circulating tumor cells (CTCs) and the metastasis of nasopharyngeal carcinoma. In the present study, we quantified the plasma levels of EBV DNA/RNAs, such as LMP1, LMP2, BART and EBER1 with real-time quantitative PCR, and CTCs with a CellSpotter Analyzer in NPC patients, with or without metastasis. Then the correlation of each biomarker with other biomarkers and tumor metastasis was analyzed. Our data indicated that the plasma levels of EBV LMP1, BART, EBER1, along with CTCs were significantly higher in metastatic NPC patients than in non-metastatic patients. Plasma LMP1 DNA and EBER1 discriminate metastatic NPC patients from non-metastatic patients, correlate with tumor stage and node stage for metastatic NPC patients. In summary, there were significantly higher plasma levels of Epstein-Barr Virus DNAs / RNAs in nasopharyngeal carcinoma patients. LMP1 DNA and EBER1 RNA correlated with the metastasis of nasopharyngeal carcinoma.