Cordycepin Affects Multiple Apoptotic Pathways to Mediate Hepatocellular Carcinoma Cell Death

Background: Cordycepin possesses anti-inflammatory, anti-metastatic and anti-tumor properties. Objective: The present study investigates the anti-hepatocellular carcinoma activities of cordycepin in in vitro and in vivo models. Method: Cell viability, apoptosis rate, intracellular reactive oxygen species (ROS) level and mitochondrial membrane potential (MMP) were determined by 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide bromide assay, annexin V/propidium iodide double staining, 2', 7'-dichlorfluorescein-diacetate and 5,5', 6,6'-tetrachloro-1,1', 3,3' tetraethylbenzimidazolylcarbocyanine iodide (JC-1) staining respectively. The expressions of pro-apoptosis and anti-apoptosis proteins were detected by western blot. A PLC/PRL/5-xenografted nude mouse model was applied to further confirm the anti-tumor activities of cordycepin. Results: Cordycepin suppressed cell viability, enhanced apoptotic rate, inhibited cell proliferation and increased cleaved poly (ADP-ribose) polymerase (PARP) level. Apoptotic alteration on mitochondria and abnormal changes on b-cell lymphoma 2 (Bcl-2) and b-cell lymphoma-extra large (Bcl-xL) levels were observed in cordycepin-treated cells. Furthermore, cordycepin suppressed the activation of extracellular signaling-regulated kinase (ERKs) and mammalian target of rapamycin (mTOR) in both PLC/PRF/5 and HepG2 cells. Finally, PLC/PRL/5-xengrafted BALB/c athymic nude mice were performed to confirm cordycepin's anti-tumor action. Conclusion: Our finding suggests that the anti-hepatocellular carcinoma properties of cordycepin are related to its modulation of multiple anti-apoptotic and pro-apoptotic pathways. Our study provides an experimental evidence for cordycepin as a rational agent for hepatocellular carcinoma treatment.