Heat Shock Protein 90α Provides an Effective and Novel Diagnosis Strategy for Nasopharyngeal Carcinoma.

INTRODUCTION Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus (EBV)-associated tumor occurring in southeastern Asia. Due to insidious onset, it is difficult to diagnose NPC from clinical symptoms. Thus, there is an urgent need for non-invasive, high-performance biomarkers to aid the clinical diagnosis of NPC. Heat shock protein 90α (HSP90α) is an important member of the heat shock protein family that significantly increases under stress conditions such as oxidation and tumors. This is the first investigation of the role of Hsp90α in the diagnosis and progress of NPC. METHODS Plasma Hsp90α was detected by ELISA in 196 newly diagnosed NPC patients, 76 corresponding post-treatment NPC patients, 230 VCA-IgA-positive normal subjects and 106 healthy controls. RESULTS (1) The level of Hsp90α in plasma of 196 NPC patients was (212.16 ± 144.32) ng/ml, which was significantly higher than that in VCA-IgA-positive normal subjects (68.12 ± 64.94 ng/ml, P < 0.001) and healthy controls (35.87 ± 17.47 ng/ml, P < 0.001); (2) the levels of Hsp90α in patients with NPC in the early stage (I + II), stage III and stage IV were significantly different (159.69 ± 117.12 pg/ml vs. 195.24 ± 126.38 pg/ml vs. 250.85 ± 164.66 pg/ml, P = 0.018 and P = 0.029, respectively). The level of Hsp90α in plasma in patients with metastasis of NPC and those without metastasis was significantly different (P < 0.001); (3) Hsp90α is closely related to EBV DNA levels, but not to the VCA-IgA titer and EA-IgA titer; (4) the levels of Hsp90α in plasma of patients with NPC before and after treatment were significantly different (212.16 ± 144.32 pg/ml vs. 62.36 ± 34.04 pg/ml, P < 0.001); (5) the ROC curves demonstrated that the sensitivity of plasma Hsp90α in distinguishing NPC patients from healthy controls was 74.50% and the specificity was 99.10% (AUC = 0.931, 95% CI 0.903-0.958). CONCLUSION The study found that the plasma HSP90α level is closely related to the clinical stage, metastasis and therapeutic effect of NPC. HSP90α may serve as a new biomarker for diagnosis and treatment of NPC.