7-Methoxyheptaphylline Enhances TRAIL-Induced Apoptosis of Colorectal Adenocarcinoma Cell <i>via</i> JNK-Mediated DR5 Expression

Abstract

A cytokine known as TNF-related apoptosis-inducing ligand (TRAIL) has the ability to precisely cause the death of cancer cells, while normal cells are left undisturbed. Recent studies show that certain cancer cells are sensitive to the apoptotic effect of TRAIL. In this study, HT29 colorectal adenocarcinoma cells exposed to TRAIL were treated with heptaphylline and 7methoxyheptaphylline from Clausena harmandiana in an effort to comprehend the mechanisms involved behind this activity. The MTT test was utilized to determine cell survival, and phase contrast microscopy was used to examine cell morphology. Through using real-time RT-PCR, Western blotting, and RT-PCR, the molecular mechanisms were investigated. According to the findings, whilst hepataphylline caused cytotoxicity in normal colon FHC cells, in comparison to healthy colon FHC cells, 7-methoxyheptaphylline inhibited cancer cells in a concentrationdependent manner. Heptaphylline alone or in conjunction with TRAIL showed no discernible effect on TRAL-induced HT29 cell death, but 7-methoxyheptaphylline boosted caspase-3 cleavage. The study showed that the JNK pathway was responsible for the 7methoxyheptaphylline's enhancement of the DR5 (death receptor 5) mRNA, TRAIL receptor, and protein. The results demonstrated that the 7-methoxyheptaphylline of Clausena harmandiana increased the expression of DR5 via the JNK pathway, intensifying TRAILinduced HT29 cell death.