TNFα induces Ca2+ influx to accelerate extrinsic apoptosis in hepatocellular carcinoma cells
نویسندگان
چکیده
BACKGROUND Tumor necrosis factor-α has been proven an effective anticancer agent in preclinical studies. However, the translation of TNFα from research to clinic has been blocked by significant systemic toxicity and limited efficacy at maximal tolerated dose, which need urgently to be solved. METHODS The level of cytosolic Ca2+ was assessed by Fura-2 in HCC cells. After changing cytosolic Ca2+ level by using agonists or inhibitors, cell apoptosis was detected by flow cytometry. We also detected the effect of ionomycin or parvalbumin on the anti-tumor activity of TNFα in a mice model. Lastly, we studied the roles of cytosolic Ca2+ in the mitochondrial-dependent intrinsic apoptosis pathway. RESULTS Here, we demonstrated that TNFα induced extracellular Ca2+ influx into cytoplasm through transient receptor potential channel in HCC cells. Both cytosolic Ca2+ scavenger and Ca2+-binding protein PV effectively desensitized hepatocellular carcinoma cells to TNFα, whereas combination ionomycin or 1,4,5-inositol triphosphate significantly sensitized HCC cells to TNFα, indicating that the increased level of cytosolic Ca2+ was positively correlated with the TNFα-induced cell apoptosis in vitro. In a nude mice xenograft model, our data revealed that TNFα combined with ionomycin remarkably synergized the anti-tumor effect of TNFα. Furthermore, we found that TNFα-mediated extracellular Ca2+ influx accelerated TNFα-induced extrinsic apoptosis through activating calpain/IAP/caspase3 pathway. CONCLUSIONS Our study provides the evidence supporting a novel mechanism by which TNFα induces extracellular Ca2+ influx to enhance cell apoptosis and suggests that increasing the level of cytosolic Ca2+ might be an alternative strategy to improve the pro-apoptotic activity of TNFα in HCC cells, although suitable chemical or biological reagents need to be further tested.
منابع مشابه
Downregulation of Kinesin Spindle Protein Inhibits Proliferation, Induces Apoptosis and Increases Chemosensitivity in Hepatocellular Carcinoma Cells
Background: Kinesin spindle protein (KSP) plays a critical role in mitosis. Inhibition of KSP function leads to cell cycle arrest at mitosis and ultimately to cell death. The aim of this study was to suppress KSP expression by specific small-interfering RNA (siRNA) in Hep3B cells and evaluate its anti-tumor activity. Methods: Three siRNA targeting KSP (KSP-siRNA #1-3) and one mismatched-siRNA (...
متن کاملOpium induces apoptosis in Jurkat cells via promotion of pro-apoptotic and inhibition of anti-apoptotic molecules
Objective(s): The aim of this study was to determine the important molecules involved in apoptosis induction by opium in Jurkat cell line. Materials and Methods: Jurkat cells were incubated 48 hrs with2.86×10-5 g/ml concentration of opium and apoptosis as well as expression levels of related molecules weremeasured. Results: Our results demonstrated that 50.3±0.2 percent of opium treated Jurka...
متن کاملIn Vitro Challenge using Thymoquinone on Hepatocellular Carcinoma (HepG2) Cell Line
Black seed (Nigella sativa) is considered as a biological response modifier. Thymoquinone (TQ) is the bioactive and the most abundant constituent of the volatile oil of this seed which has been shown to possess anti-inflammatory, antioxidant and anti-neoplastic effects. In this study, the effect of TQ on HepG2 cell line was investigated in an attempt to identify its potential mechanism of actio...
متن کاملIn Vitro Challenge using Thymoquinone on Hepatocellular Carcinoma (HepG2) Cell Line
Black seed (Nigella sativa) is considered as a biological response modifier. Thymoquinone (TQ) is the bioactive and the most abundant constituent of the volatile oil of this seed which has been shown to possess anti-inflammatory, antioxidant and anti-neoplastic effects. In this study, the effect of TQ on HepG2 cell line was investigated in an attempt to identify its potential mechanism of actio...
متن کاملComparative Analysis of the Effects of Valproic Acid and Tamoxifen on Proliferation, and Apoptosis of Human Hepatocellular Carcinoma WCH 17 CellLin
Background: Histone deacetylation of tumor suppressor genes such as estrogen receptor alpha (ERα) can induce cancer, which is reversible by epi-drugs such as valproic acid (VPA). The previous result indicated that tamoxifen (TAM) induced apoptosis in hepatocellular carcinoma (HCC). This study was designed to assess the apoptotic and antiproliferative effects of VPA and TAM and also the ef...
متن کامل