e-3330 and Liver-Neoplasms

APE1/Ref-1 is a main regulator of cellular response to oxidative stress via DNA-repair function and co-activating activity on the NF-κB transcription factor. APE1 is central in controlling the oxidative stress-based inflammatory processes through modulation of cytokines expression and its overexpression is responsible for the onset of chemoresistance in different tumors including hepatic cancer. We examined the functional role of APE1 overexpression during hepatic cell damage related to fatty acid accumulation and the role of the redox function of APE1 in the inflammatory process. HepG2 cells were stably transfected with functional and non-functional APE1 encoding plasmids and the protective effect of APE1 overexpression toward genotoxic compounds or FAs accumulation, was tested. JHH6 cells were stimulated with TNF-α in the presence or absence of E3330, an APE1 redox inhibitor. IL-8 promoter activity was assessed by a luciferase reporter assay, gene expression by Real-Time PCR and cytokines (IL-6, IL-8, IL-12) levels measured by ELISA. APE1 over-expression did not prevent cytotoxicity induced by lipid accumulation. E3330 treatment prevented the functional activation of NF-κB via the alteration of APE1 subcellular trafficking and reduced IL-6 and IL-8 expression induced by TNF-α and FAs accumulation through blockage of the redox-mediated activation of NF-κB. APE1 overexpression observed in hepatic cancer cells may reflect an adaptive response to cell damage and may be responsible for further cell resistance to chemotherapy and for the onset of inflammatory response. The efficacy of the inhibition of APE1 redox activity in blocking TNF-α and FAs induced inflammatory response opens new perspectives for treatment of inflammatory-based liver diseases.

Topics: Benzoquinones; Carcinoma, Hepatocellular; Cell Line, Tumor; DNA-(Apurinic or Apyrimidinic Site) Lyase; Fatty Acids; Gene Expression; Gene Expression Regulation, Neoplastic; Hep G2 Cells; Humans; Interleukin-8; Liver Neoplasms; NF-kappa B; Oxidation-Reduction; Promoter Regions, Genetic; Propionates; Transcriptional Activation; Tumor Necrosis Factor-alpha

To investigate the reduction of cell viability in human hepatocellular carcinoma (HCC) cell lines induced by inhibition of nuclear factor kappa B (NF kappa B).. HLE, SKHep1, and HepG2 were incubated and E3330 was used to compare the stimulation of some chemotherapeutic drugs with that of TNF family, Fas ligand, TNF alpha and TNF-related apoptosis-inducing ligand (TRAIL) at the point of the reduction of cell viability by inhibiting NF kappa B.. E3330 decreased NF kappa B levels in HLE cells stimulated by TNF and TRAIL. The cytotoxicity of the combination of TRAIL, TNF alpha, Fas ligand, and E3330 increased synergistically in a dose-dependent manner compared to either E3330 alone in all HCC cell lines by MTT assay. However, the combination of some chemotherapeutic drugs and E3330 did not decrease the cell viability.. Inhibition of NF kappa B sensitizes human HCC cell lines to TNF-mediated apoptosis including TRAIL, and TRAIL-based tumor therapy might be a powerful potential therapeutic tool in the treatment of human HCC.

Topics: Apoptosis; Apoptosis Regulatory Proteins; Benzoquinones; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Proliferation; Cell Survival; Genes, Reporter; Humans; Liver Neoplasms; Membrane Glycoproteins; NF-kappa B; Propionates; TNF-Related Apoptosis-Inducing Ligand; Tumor Necrosis Factor-alpha