Dichotomic Role of Low-Concentration EGCG in the Oxaliplatin Sensitivity of Colorectal Cancer Cells

Although epigallocatechin-3-gallate (EGCG) can potentiate chemotherapeutic drugs at high concentrations, its clinical translation is hampered by exceeding possible concentration thresholds. This study proposes a dichotomous use of low-concentration EGCG in chemotherapy. During the first cycle of combined treatment with oxaliplatin (OXA), low-concentration EGCG antagonized the cytotoxic effect of OXA on colorectal cancer (CRC) cells. However, when OXA was subsequently administered, the sensitivity of CRC cells markedly increased. Although low-concentration EGCG counteracted OXA, it reduced the OXA-induced secretion of vascular endothelial growth factor by tumor cells, thereby contributing to the increase in the sensitivity of tumor cells to the second round of OXA treatment. Therefore, low-concentration EGCG showed potential as a viable adjunct to modulate chemosensitivity in CRC.