Activity of Potassium Channels in CD8⁺ T Lymphocytes: Diagnostic and Prognostic Biomarker in Ovarian Cancer?

CD8⁺ T cells play a role in the suppression of tumor growth and immunotherapy. Ion channels control the Ca²⁺-dependent function of CD8⁺ lymphocytes such as cytokine/granzyme production and tumor killing. Kv1.3 and KCa3.1 K⁺ channels stabilize the negative membrane potential of T cells to maintain Ca²⁺ influx through CRAC channels. We assessed the expression of Kv1.3, KCa3.1 and CRAC in CD8⁺ cells from ovarian cancer (OC) patients (n = 7). We found that the expression level of Kv1.3 was higher in patients with malignant tumors than in control or benign tumor groups while the KCa3.1 activity was lower in the malignant tumor group as compared to the others. We demonstrated that the Ca²⁺ response in malignant tumor patients is higher compared to control groups. We propose that altered Kv1.3 and KCa3.1 expression in CD8⁺ cells in OC could be a reporter and may serve as a biomarker in diagnostics and that increased Ca²⁺ response through CRAC may contribute to the impaired CD8⁺ function.