The following is a summary of “High dose Vitamin C inhibits PD-L1 by ROS-pSTAT3 signal pathway and enhances T cell function in TNBC,” published in the January 2024 issue of Oncology by Zhao et al.

Vitamin C (VitC) has exhibited remarkable anti-tumor effects over time. Recently, administering high doses of VitC intravenously has demonstrated even more pronounced anti-tumor efficacy. Nevertheless, the precise functions and underlying mechanisms by which high-dose VitC influences cancer immunity remain incompletely understood. This study aims to unravel the impact of high-dose VitC on PD-L1 expression in triple-negative breast cancer (TNBC) and explore the potential mechanisms involved. The results extracted by the researchers showcased VitC’s ability to impede PD-L1 expression in breast cancer cell lines while concurrently augmenting the anti-tumor capabilities of T cells. Their investigation uncovered that VitC effectively curtailed PD-L1 transcription by modulating the ROS-pSTAT3 signal pathways. These in vitro findings were corroborated in an in vivo study using immunocompetent mice, where VitC notably suppressed tumor growth.

Additionally, it enhanced the infiltration and functionality of CD8+ T cells within the tumor microenvironment. These findings elucidate the impact of high-dose VitC on PD-L1 expression and underscore its potential as an immunomodulator for cancer therapy. Ultimately, this study provides critical insights into the role of high-dose VitC as a promising adjunct in cancer treatment, particularly in modulating the immune response against triple-negative breast cancer (TNBC).

Source: sciencedirect.com/science/article/abs/pii/S156757692301648X