Plasma exosome-derived connexin43 as a promising biomarker for melanoma patients

Yue Shen, Ming Li, Li Liao, Suyue Gao, Yongzhen Wang

To examine the levels of exosome-derived connexin 43 (Cx43) in plasma and estimate its forecast value in patients with melanoma. We measured the plasma exosome-derived Cx43 levels in the plasma of 112 melanoma patients and 50 healthy controls. The plasma exosome-derived Cx43 levels in patients with melanoma were substantially downregulated as opposed to the levels in healthy controls (P < 0.001). Kaplan-Meier analysis indicated that overall survival (OS) and disease-free survival (DFS) were poorer in patients with melanoma who exhibited lower levels of plasma exosome-derived Cx43 (both P < 0.001). The levels of plasma exosome-derived Cx43 were considerably elevated in patients with melanoma whose tumor was situated in the skin, tumor size < 10 cm, with Clark level I-III, TNM stages IIb-IV, and had no lymph node metastasis as opposed to patients whose tumor was situated in the viscera or mucosa, tumor size ≥ 10 cm, Clark level IV-V, TNM stages IIb-IV and had lymph node metastasis (all P < 0.05). The receiver operating characteristic (ROC) of plasma exosome-derived Cx43 for forecasting 5-year DFS in patients with melanoma was 0.78 (95% confidence interval (CI): 0.70-0.86), with a specificity of 77.78% and a sensitivity of 81.55%. The ROC of plasma exosome-derived Cx43 for forecasting 5-year OS of patients with melanoma was 0.77 (95% CI: 0.68-0.84), with a specificity of 80.0% and sensitivity of 65.98%. The overall findings indicated that the levels of plasma exosome-derived Cx43 in patients with melanoma were considerably downregulated. It can therefore be inferred that the levels of plasma exosome-derived Cx43 might be a prospective prognostic indicator for 5 5-year OS and 5-year DFS of patients with melanoma.