BackgroundMultidrug resistance (MDR) frequently contributes to the failure of chemotherapeutic treatments in patients diagnosed with hepatocellular carcinoma (HCC). Revealing the molecular mechanism of MDR is indispensable for the development of effective chemotherapeutic drugs.PurposeDue to the low-toxicity modulators to inhibit MDR, we considered that Kanglaite (KLT) is a potential agent for reversing MDR in HCC.Materials and MethodsBEL-7402/5-fluorouracil (5-FU) and HepG2/adriamycin (ADM) were analyzed for cell viability, colony formation assay, cell scratch assay, and cell cycle analysis and apoptosis assay by flow cytometry. The expression of PARP, caspase-3, Bax, Bcl-2, CDC25C, Cyclin B1 and phosphorylation of PTEN, PI3K, and AKT in HepG2/ADM cells were detected by western blotting.ResultsThe proliferation of drug-resistant cell lines BEL-7402/5-FU and HepG2/ADM pretreated with KLT was significantly inhibited when compared with drug alone. KLT could increase the accumulation of ADM in HepG2/ADM cells. In this study, we found that KLT treatment notably reduced cell viability, induced apoptosis and cell cycle arrest in human HepG2/ADM and BEL-7402/5-FU cells, and effectively reversed the MDR by p-glycoprotein (P-gp) inhibition. Moreover, KLT decreased the phosphorylation of AKT and PI3K in KLT-treated HepG2/ADM cells. These data together implied that KLT might reverse drug resistance in HCC by blocking the PI3K/AKT signaling.ConclusionWe demonstrated that KLT reversed MDR of human HCC by inducing apoptosis and cell cycle arrest via the PI3K/AKT signaling pathway.

Triptolide is a diterpene triepoxide compound extracted from the medicinal plant, Tripterygium wilfordii Hook F. The aim of the present study was to determine whether triptolide inhibits the proliferation of breast cancer cells and to further investigate the associated molecular mechanisms. The effects of triptolide on the cell viability of three breast cancer cell lines, specifically, highly metastatic MDA-MB-231, human epidermal growth factor receptor 2-positive BT-474 and estrogen receptor-positive MCF7 cells, were measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and apoptosis assays. Western blot analysis was performed to investigate the expression levels of β-catenin in the control and triptolide-treated cells. The results demonstrated that triptolide treatment caused cell death in the three types of malignant cell lines. Treatment with 25 nM triptolide for 48 h exhibited marked inhibitory effects on the cell viability of the three types of cells, with greater effects observed in BT-474 cells compared with the other two cell types. When compared with the cells not treated with triptolide, 50 nM triptolide treatment resulted in apoptosis of MDA-MB-231, BT-474 and MCF7 cells with apoptotic rates of ~80%. Western blot analysis indicated that triptolide treatment of MDA-MB-231, BT-474 and MCF7 cells decreased the expression levels of β-catenin to 5–10% of the levels observed in the cells treated with dimethyl sulfoxide only. Therefore, the results of the present study indicate that triptolide induces the apoptosis of breast cancer cells via a mechanism associated with the Wnt/β-catenin signaling pathway.