Serum CD166: A novel biomarker for predicting nasopharyngeal carcinoma response to radiotherapy.

The present study aimed to identify whether CD166 can be used as a biomarker for predicting the response of nasopharyngeal carcinoma (NPC) to radiotherapy. The serum concentration of CD166 in patients with NPC were detected by enzyme-linked immunosorbent assay. The secreted level of CD166 with radioresistant NPC was significantly higher than that with radiosensitive NPC. , the CD166 positive rate in the CNE2 cell membrane was significantly lower than that in the CNE2R cell membrane. The magnetic-activated cell sorting technology was used to obtain CNE-2R-CD166(+) and CNE-2R-CD166(-) cell lines. Then radiosensitivity, cell proliferation, and apoptosis were assessed using colony formation assay, cell counting kit 8 assay (CCK-8), and flow cytometry, respectively. The radiation sensitivity ratio was 1.28, indicating that the CNE2R-CD166(-) cells had a stronger radiation sensitivity. The result of CCK-8 assay indicated that the survival fraction of CNE2R-CD166(+) cells was significantly higher than that of CNE2R-CD166(-) cells. The apoptotic rate of CNE2R-CD166(+) cells was significantly lower than that of CNE2R-CD166(-) cells. Our data demonstrate that the secreted protein CD166 may be can used as a biomarker for predicting the response of NPC to radiotherapy.