Role of Pannexin1 channels in the resistance of I-10 testicular cancer cells to cisplatin mediated by ATP/IP3 pathway

Cisplatin (DDP) is the most commonly used drug in testicular cancer. However, drug resistance severely limits its clinical use and the underlying mechanisms need to be further clarified. The aim of present study was to investigate the role of ATP/IP3 pathway mediated by pannexin1 (Panx-1) channels on DDP-induced apoptosis and to reveal the potential mechanisms of DDP-resistance in testicular cancer. We found that the expression of Panx-1 in I-10/DDP cells (DDP-resistance) was decreased compared with parental I-10 cells determined by western blotting and immunofluorescence assay. To further clarify the role of Panx-1 in DDP resistance, Panx-1 function was modulated by overexpression and knockdown of Panx-1 expression. Panx-1 overexpression increased DDP-induced apoptosis, ATP release and IP3 levels. On the contrary, Panx-1 silencing decreased DDP-induced apoptosis, ATP release and IP3 levels. Apyrase (hydrolyzing extracellular ATP) or xestospongin C (antagonizing IP3 receptor) also decreased DDP-induced apoptosis. Our findings demonstrate that Panx-1 is involved in DDP-resistance and ATP/IP3 pathway mediated by Panx-1 channels participates in DDP-induced apoptosis in testicular cancer. Panx-1 modulation may be interesting to amplify the clinical effect of DDP and reverse the resistance of testicular cancer cells to DDP.