Gegen Qinlian decoction remodels tumor immune microenvironment and inhibits aerobic glycolysis with the synergistic combination of CPT-11 chemotherapy in colorectal cancer therapy

Abstract

Ethnopharmacological relevance

Although several traditional Chinese medicine formulas have demonstrated remarkable outcomes in suppressing the severe gastrointestinal toxicity induced by irinotecan (CPT-11), few studies have investigated whether enhanced anti-cancer efficacy and reduced intestinal toxicity can be achieved through co-administration. CPT-11, as a first-line drug for treating colorectal cancer, has the side effect of intestinal toxicity. Previous studies have primarily focused on using traditional Chinese medicine to alleviate diarrhea caused by CPT-11. The combination of the classic Chinese medicine prescription Gegen Qinlian decoction (GQD) extract and CPT-11 can significantly reduce its intestinal toxicity. However, the mechanism by which it enhances anti-cancer effects remains to be elucidated.

Aim of study

To investigate the combined effects of GQD and CPT-11 on colorectal cancer progression and intestinal toxicity.

Materials and methods

The CT-26 xenograft tumor-bearing mouse model was established to evaluate the synergistic antitumor effects of GQD extract and CPT-11. Tumor size and tumor tissue changes were assessed, and flow cytometry was employed to analyze immune cell populations, thereby evaluating the impact of the combined treatment on tumor growth inhibition and immune modulation. Under anaerobic glycolysis conditions, glucose uptake and cell viability of CT26 cells were measured, and Western blotting analysis was used to determine the protein expression of PKM2 and GAPDH in tumors, assessing the metabolic impact of GQD extract on cancer cells. Flow cytometry was also used to assess the polarization of macrophages in colon tissue, and ELISA was employed to measure cytokine levels in colon tissue, evaluating the protective effect of GQD extract on the colon.

Results

The combination of GQD extract and CPT-11 significantly increased tumor growth suppression and decreased intestinal toxicity in the mouse model. The anti-cancer synergy was reduced Treg cell immunosuppression and increased CD4⁺ and CD8⁺ T cell populations. GQD extract regulated glucose uptake and cell viability in CT-26 cells under anaerobic glycolysis, potentially disrupting cancer cell glycolysis. GQD also alleviated intestinal toxicity by modulating cytokine levels and promoting macrophage polarization from M1 to M2 in colon tissues.

Conclusion

The study indicates that GQD extract improves CPT-11 efficacy in treating colorectal cancer and provides insights into the synergistic effects of TCM formulas in cancer treatment.