Caffeic Acid Phenethyl Ester Induces Apoptosis Of Human Colorectal Cancer Cell Line HT-29by Inhibition Of NF-κB Signaling Pathway

OBJECTIVE: To investigate the effect of caffeic acid phenethyl ester oninduction of apoptosis in human colorectal cancer cell line HT-29and its molecularmechanisms.MEHTODS: The cells of human colorectal carcinoma cell line HT-29weretreated with CAPE at different concentration. The proliferation inhibition wasexamined by MTT assay. AO/EB and FCM were used to detect apoptosis. Westernblot was used to analyze the expression of NF-κB, Bax and Bcl-2proteins after CAPEtreatment. The activity of Caspase9and Caspase3were detected by ColorimetricAssay Kit after treatment with the CAPE.RESULTS: CAPE can inhibit the proliferation of colorectal cancer cell lineHT-29, which were in a concentration-and time-dependent manner. AO/EB showedthat the apoptosis cells increased after the treatment of CAPE. At24h the CAPE-treated cells also showed morphological changes characteristic of apoptosis, underthe fluorescence microscope, including cell shrinkage, membrane blebbing, chromatincondensation. FCM analysis showed that cell apoptosis rate increased after exposed toCAPE in a dose dependent manner (2.5,5.0,7.5and10μg/ml) after24h. WhenHT-29cells were exposed to CAPE at various concentrations of5.0,7.5,10μg/ml for24h, the expression of NF-κB and Bcl-2were decreased in a dose-dependentmanner., but the expression of Bax was increased inversely. CAPE fostered theactivity of Caspase9and Caspase3in a dose-dependent manner, tested byColorimetric Assay Kit.CONCLUSION: CAPE inhibits the proliferation and induces apoptosis in human colon cancer cell line HT-29, induction of apoptosis of CAPE may be invovledin down-regulation of NF-κB and the ratio of Bcl-2/Bax, then Caspase9andCaspase3activation.