High-does Vitamin C promotes mitochondrial biogenesis in HCT116 colorectal cancer cells by regulating the AMPK-PGC1α signaling pathway

Mitochondrial dysfunction is closely associated with cancer development. Tumor cells typically exhibit altered metabolism characterized by increased glycolysis and decreased oxidative phosphorylation. Therefore,enhancing mitochondrial biogenesis and functionality in tumor cells holds promise as a potential approach for cancer prevention and therapy. High dose of vitamin C have demonstrated antitumor activity and the ability to mitigate the Warburg effect . However, its role in modulating mitochondrial biogenesis and function remains unclear. Here, we evaluated the altered mitochondrial functional status of HCT116 colorectal cancer cells compared to FHC normal colorectal epithelial cells, as well as the impact of vitamin C on mitochondrial biosynthesis and function in HCT116 colorectal cancer cells, and investigated the potential regulatory mechanisms. The findings demonstrated that HCT116 colorectal cancer cells exhibited reduced levels of mitochondrial electron transport chain complexes III and IV, alongside decreased expression of mitochondrial-specific transcription factor A (TFAM) and diminished mitochondrial DNA (mtDNA) content. However, treatment with vitamin C markedly upregulated the transcription and expression of major mitochondrial regulators, in particular peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α), nuclear respiratory factor 2 (NRF2), and TFAM. Furthermore, vitamin C significantly stimulated mitochondrial biogenesis, as evidenced by increased mtDNA content, elevated mitochondrial mass, and enhanced expression of complexes III and IV within the mitochondrial respiratory chain. These improvements were associated with heightened AMPK phosphorylation, while the effects were substantially attenuated upon application of Compound C, a specific AMPK inhibitor. In summary, our findings underscore vitamin C’s potential as a therapeutic approach to alleviate mitochondrial dysfunction in HCT116 cancer cells, primarily through the activation of the AMPK-PGC1α signaling pathway.