ABSTRACT
Docetaxel (DTX), a semi-synthetic analogue of paclitaxel (taxol), is known to exert potent anticancer activity in various cancer cells by suppressing normal microtubule dynamics. In this study, we examined how the anticancer effect of DTX is regulated by polyphenols extracted from Korean Artemisia annua L. (pKAL) in DU145 prostate cancer cells (mutant p53) and HCT116 colorectal cancer cells (wild-type p53). Here, we show that the anticancer effect of DTX was enhanced more significantly by pKAL in HCT116 cells than in DU145 cells via phase-contrast microscopy, CCK-8 assay, Western blot, and flow cytometric analysis of annexin V/propidium iodide-stained cells. Notably, mutant p53 was slightly downregulated by single treatment of pKAL or DTX in DU145 cells, whereas wild-type p53 was significantly upregulated by pKAL or DTX in HCT116 cells. Moreover, the enhanced anticancer effect of DTX by pKAL in HCT116 cells was significantly associated with the suppression of DTX-induced p53 upregulation, increase of DTX-induced phospho-p38, and decrease of DTX-regulated cyclin A, cyclin B1, AKT, caspase-8, PARP1, GM130, NF-κB p65, and LDHA, leading to the increased apoptotic cell death and plasma membrane permeability. Our results suggest that pKAL could effectively improve the anticancer effect of DTX-containing chemotherapy used to treat various cancers expressing wild-type p53.
ABSTRACT
Recent studies suggest that the anticancer activity of ß-lapachone (ß-Lap) could be improved by different types of bioactive phytochemicals. The aim of this study was to elucidate how the anticancer effect of ß-Lap is regulated by polyphenols extracted from Korean Artemisia annua L. (pKAL) in parental HCT116 and oxaliplatin-resistant (OxPt-R) HCT116 colorectal cancer cells. Here, we show that the anticancer effect of ß-Lap is more enhanced by pKAL in HCT116-OxPt-R cells than in HCT116 cells via a CCK-8 assay, Western blot, and phase-contrast microscopy analysis of hematoxylin-stained cells. This phenomenon was associated with the suppression of OxPt-R-related upregulated proteins including p53 and ß-catenin, the downregulation of cell survival proteins including TERT, CD44, and EGFR, and the upregulation of cleaved HSP90, γ-H2AX, and LC3B-I/II. A bioinformatics analysis of 21 proteins regulated by combined treatment of pKAL and ß-Lap in HCT116-OxPt-R cells showed that the enhanced anticancer effect of ß-Lap by pKAL was related to the inhibition of negative regulation of apoptotic process and the induction of DNA damage through TERT, CD44, and EGFR-mediated multiple signaling networks. Our results suggest that the combination of pKAL and ß-Lap could be used as a new therapy with low toxicity to overcome the OxPt-R that occurred in various OxPt-containing cancer treatments.