Synergistic effects of Caffeic acid phenethyl ester (CAPE) along with 5-FU via apoptotic gene expression in human colorectal cells (SW-742)

Background and purpose: 5-Fluorouracil (5-FU) is a commonly used chemotherapy drug for colorectal cancer; however, resistance to it has highlighted the need for new treatment strategies. This study aimed to evaluate the effects of Caffeic Acid Phenethyl Ester (CAPE) in combination with 5-FU by assessing the expression of apoptotic (BAX, Bcl-2) and inflammatory genes (NF-κB) in human colorectal cancer cells (SW-742). Materials and methods: In this experimental study, SW-742 cells were exposed to varying concentrations of 5-FU (1.56, 3.125, 6.25, 12.5, 25, 50, and 100 μM) and CAPE (1, 5, 10, 20, 50, 100, and 200 μM) for 24 and 48 hours. Mixtures of the two compounds were also tested. Cell viability and IC50 were assessed Materials and Methods: In this experimental study, SW-742 cells were exposed to varying concentrations of 5-FU (1.56, 3.125, 6.25, 12.5, 25, 50, and 100 μM) and CAPE (1, 5, 10, 20, 50, 100, and 200 μM) for 24 and 48 hours. Mixtures of the two compounds were also tested. Cell viability and IC50 were assessed using MTT assay. RT-PCR was employed to measure changes in the expression of apoptotic and inflammatory genes. Data were analyzed using Compusyn software and Prism Ver. 3 with one-way ANOVA. Results: After 48 hours, a dose-dependent reduction in SW-742 cell viability was observed with combinations of 5-FU and CAPE. The Compusyn software analysis revealed a strong synergistic relationship between 5-FU and CAPE in the mixtures of 6.25 μM 5-FU (IC30) + 10 μM CAPE (IC10) and 6.25 μM 5-FU (IC30) + 20 μM CAPE. RT-PCR analysis showed that the combination of 6.25 μM 5-FU (IC30) + 10 μM CAPE (IC10) significantly increased BAX expression (P< 0.001) compared to both 6.25 μM 5-FU (IC30) alone (P< 0.001) and 10 μM CAPE (IC10) alone (P< 0.001). In contrast, Bcl-2 expression was significantly reduced (P< 0.05) compared to 10 μM CAPE (IC10) alone. Moreover, NF-κB expression was significantly lower in the combination treatment compared to both 6.25 μM 5-FU (IC30) alone (P< 0.01) and 10 μM CAPE (IC10) alone (P< 0.01). Conclusion: This study demonstrated that 5-FU and CAPE act synergistically to reduce SW-742 colorectal cancer cell viability by modulating the expression of BAX, Bcl-2, and NF-κB. Given its antioxidant properties and synergistic potential, CAPE may enhance the effectiveness of 5-FU in colorectal cancer treatment.