Integrative study to determine the anti-tumor role and mechanism of Chouchunpi San in colorectal cancer

The herbal formula Chouchunpi San (CCPS) is a traditional formula that has been widely used and proven effective in various clinical cancer treatments. However, the mechanism of its anticancer effect remains unclear. This study aims to determine the anti-tumor effect of CCPS on colorectal cancer (CRC) in vivo and in vitro and to explore the underlying molecular mechanisms. Cell counting kit-8 assays, colony-forming assays, and flow cytometry for cell cycle and apoptosis assays were employed to determine the anti-tumor roles of CCPS. Liquid chromatography-mass spectrometry (LC-MS), network pharmacology, molecular docking, analysis of real-world clinical datasets of CRC, and western blotting were conducted to explore the molecular mechanism of CCPS on CRC. CRC xenografted mouse model, western blotting, and public CRC data analysis were conducted to evaluate the anti-tumor efficacy and mechanisms of CCPS on CRC. CCPS suppresses the growth of CRC cells and increases the number of apoptotic cells dose-dependently. CCPS targets and significantly downregulates RPA1 and enhances the phosphorylation of its downstream effectors, ATR and CHK1, which are critical for CRC progression. Additionally, CCPS shows a comparable anti-tumor effect in CRC xenografted mouse models compared to Capecitabine, a chemotherapy drug commonly used in clinics. Our findings demonstrate the potential use of CCPS in cancer treatment by suppressing cancer cell growth and modulating the RPA1/ATR/CHK1 signaling pathway in CRC. Further investigations on the application of CCPS in cancer therapies could be extended to evaluate the potential in vivo toxicity and adverse events, as well as the synergistic effect of CCPS in combination with other chemotherapeutic agents.