The synergistic effects of oxaliplatin and piperlongumine on colorectal cancer are mediated by oxidative stress

Oxaliplatin-based chemotherapy is recommended as the first-line therapeutic regimen for metastatic colorectal cancer. However, long-term and repeated oxaliplatin therapy leads to drug resistance and severe adverse events, which hamper its clinical application. Thus, chemosensitizers are urgently required for overcoming oxaliplatin resistance and toxicity. Here, the anticancer effects of oxaliplatin combined with piperlongumine (PL), a molecule promoting reactive oxygen species (ROS) generation, in colorectal cancer, were assessed. We demonstrated that oxaliplatin elevated cellular ROS amounts and showed synergistic anticancer effects with PL in colorectal cancer cells. These anticancer effects were mediated by mitochondrial dysfunction and endoplasmic reticulum (ER) stress apoptotic-associated networks. Meanwhile, blockage of ROS production prevented apoptosis and fully reversed mitochondrial dysfunction and ER stress associated with the oxaliplatin/PL combination. Moreover, xenograft assays in mouse models highly corroborated in vitro data. In conclusion, this study provides a novel combination therapy for colorectal cancer, and reveals that manipulating ROS production might constitute an effective tool for developing novel treatments in colorectal cancer.