Silencing of KIF2C enhances the sensitivity of hepatocellular carcinoma cells to cisplatin through regulating the PI3K/AKT/MAPK signaling pathway.

In the treatment of unresectable advanced hepatocellular carcinoma (HCC), cisplatin is administered transhepatic arterially for local treatment, but the clinical application of cisplatin drugs is frequently hindered by the emergence of drug resistance. Kinesin family member 2C( KIF2C ) has been shown as oncogene in a variety of tumors. Nevertheless, its effect on cisplatin sensitivity has yet to be ascertained. Herein, we aim to investigate the impact of the KIF2C gene on cisplatin sensitivity within HCC and the plausible underlying molecular mechanism. We examined the expression level of the KIF2C gene in HCC cells by real-time quantitative reverse transcription PCR and Western blot analysis, and analyzed bioinformatically by The Gene Expression Omnibus database and The Cancer Genome Atlas database. The KIF2C gene was silenced using the small interfering RNA technology, and its effect on cisplatin drug sensitivity in HCC cells was evaluated by flow cytometry, cell proliferation, cell migration, and invasion assays. Our results indicated that KIF2C was highly expressed in HCC cells. KIF2C silencing inhibits HCC cell proliferation, migration and invasion, promotes apoptosis, and keeps the cell cycle in G2 phase. In addition, KIF2C silencing enhanced the sensitivity of HCC cells to cisplatin. KIF2C silencing down-regulates the expression levels of phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT) and mitogen-activated protein kinase 3 (MAPK3) proteins. In conclusion, KIF2C silencing amplifies the sensitivity of HCC cells to cisplatin by regulating the PI3K/AKT/MAPK signaling pathway. Consequently, targeting KIF2C shows great application potential as a strategy for enhancing the effectiveness of HCC treatment.

Effects of 2-dodecyl-6-methoxycyclohexa-2,5-diene-1,4-dione on autophagy and the PI3K/AKT/mTOR signaling pathway in human cholangiocarcinoma QBC939 cells.

Background: 2-dodecyl-6-methoxycyclohexa-2,5-diene-1,4-dione (DMDD) has been reported to have good antitumor effects. The aim of this study was to investigate whether DMDD induces apoptosis and autophagy in human cholangiocarcinoma (CCA) QBC939 cells and determine its effect on the PI3K/AKT/mTOR signaling pathway. Methods: QBC939 cells were cultured in vitro and changes in cell viability were detected by the Cell Counting Kit (CCK8) assay after treatment with different concentrations of DMDD for 24, 48, and 72 h. The cells were divided into control and DMDD-treated groups (treated concentrations were 10, 15, and 20 µM/L), and the cell cycle, apoptosis, and autophagic vesicles were assessed. The expression levels of PI3K, AKT, mTOR, microtubule-associated protein 1 light chain 3 beta (LC3-II)/I, Beclin-1, and P62 were detected by Western blot. A xenograft mouse model was constructed to detect the effect of DMDD on CCA. Results: The experimental results showed that DMDD was able to inhibit proliferation, migration, and invasion and induce cell cycle arrest and autophagy of QBC939 cells. In addition, DMDD decreased the protein expression of PI3K, AKT, and mTOR and increased the expression of LC3-II/I, Beclin-1, and P62. In mice, DMDD was able to inhibit the growth of tumors. Conclusions: DMDD inhibits CCA cell viability and induces cell cycle arrest and autophagy by a mechanism that may be related to the downregulation of the PI3K/AKT/mTOR signaling pathway.

Protective Effects of 2-Dodecyl-6-Methoxycyclohexa-2,5 -Diene-1,4-Dione Isolated from Averrhoa Carambola L. (Oxalidaceae) Roots on High-Fat Diet-Induced Obesity and Insulin Resistance in Mice.

BACKGROUND/AIMS: The roots of Averrhoa carambola L. (Oxalidaceae) have long been used as a traditional Chinese medicine for the treatment of diabetes and diabetes-related diseases. 2-dodecyl-6-methoxycycyclohexa-2,5-1,4-dione (DMDD) has been isolated from A. carambola L. roots, and this study was carried out to investigate the potential beneficial effects of DMDD on obesity and insulin resistance induced by a high-fat diet (HFD) in mice. METHODS: C57BL/6J mice were fed a HFD for 16 weeks and orally administered DMDD (12.5, 25, or 50 mg/kg of body weight per day) and metformin (280 mg/kg of body weight per day) for the last 4 weeks. RESULTS: The body weights and adipose tissue weights as well as the serum levels of blood glucose, total cholesterol, triglycerides, free fatty acids, insulin, interleukin-6, and tumor necrosis factor-α were significantly decreased by DMDD, and the expression of Toll-like receptor 4 (TLR4) and myeloid differentiation factor (Myd88) in the epididymal adipose tissue was downregulated by DMDD. In contrast, insulin sensitivity was enhanced. The results of the glucose tolerance tests, insulin tolerance tests, and insulin release tests indicated that there was a marked improvement in insulin secretion, and the areas under the curve corresponding to the three tests were also significantly decreased by DMDD. The activities of superoxide dismutase and glutathione peroxidase were simultaneously enhanced, whereas the content of malondialdehyde was decreased by DMDD in the liver homogenates of the C57BL/6J mice. In addition, hepatic steatosis and adipocyte hypertrophy, as assessed by H&E staining of liver and adipose tissues, were significantly improved by DMDD. CONCLUSION: These data suggest that MDD has potential benefits for the treatment of HFD-induced obesity and insulin resistance, and its effects may be associated with improvements in lipid metabolism and inhibition of the expression of TLR4 in adipose tissues.