Cyanidin-3-O-Glucoside Combined with PGC1α Inhibitor Promotes Cancer Cell Death by Inducing Excessive Levels of ROS in Cervical Squamous Cell Carcinoma

Abstract

Cervical cancer is a global public health problem, particularly in the low-income and middle-income countries. Natural products, such as cyanidin and its derivative cyanidin-3-O-glucoside (C3G), are considered safe and nontoxic food additives, potent therapeutic options for cancer. The present study aims to evaluate the beneficial effects of C3G on cervical squamous cell carcinoma (CSCC) in vitro and explore more potential therapeutic strategies for CSCC. C3G significantly inhibited the cell growth of CSCC cells and induced cancer cell apoptosis in a dose-dependent manner. Meanwhile, C3G promoted cellular reactive oxygen species (ROS) accumulation and decreased mitochondrial membrane potential and mitochondrial mass. The antioxidant regent N-acetyl-L-cysteine (NAC) rescued the effect of C3G on CSCC cells, further demonstrating ROS’s important role in C3G treatment. To explore the underlying mechanism, autophagy-related signaling pathways were investigated, and the results showed that C3G induced cell autophagy but not mitophagy. More importantly, C3G caused a significant activation of mitochondria biogenesis through the peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) signaling pathway. C3G synergized with PGC-1α inhibitor SR-18292 induced more severe ROS accumulation and showed more potent inhibition of cell proliferation and mitochondrial membrane potential than C3G treatment alone. Thus, the present study suggests a new potential therapeutic strategy for CSCC based on the synergistic effect of C3G and PGC1α inhibitors.