pitavastatin and Liver-Neoplasms

Albeit its established efficacy as an anti-hyperlipidemic agent, pitavastatin (PIT) has been shown to have other various therapeutic effects. One of these effects is the anti-cancer activity against hepatocellular carcinoma (HCC). This effect has been evaluated in this study for the first time

Topics: Bile Acids and Salts; Caco-2 Cells; Carcinoma, Hepatocellular; Humans; Liposomes; Liver Neoplasms; Particle Size; Phospholipids; Quinolines

Hepatic ATP-binding cassette transporter A1 (ABCA1) plays a key role in high-density lipoprotein (HDL) production by apolipoprotein A-I (ApoA-I) lipidation. 3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, statins, increase ABCA1 mRNA levels in hepatoma cell lines, but their mechanism of action is not yet clear. We investigated how statins increase ABCA1 in rat hepatoma McARH7777 cells. Pitavastatin, atorvastatin, and simvastatin increased total ABCA1 mRNA levels, whereas pravastatin had no effect. Pitavastatin also increased ABCA1 protein. Hepatic ABCA1 expression in rats is regulated by both liver X receptor (LXR) and sterol regulatory element-binding protein (SREBP2) pathways. Pitavastatin repressed peripheral type ABCA1 mRNA levels and its LXR-driven promoter, but activated the liver-type SREBP-driven promoter, and eventually increased total ABCA1 mRNA expression. Furthermore, pitavastatin increased peroxisome proliferator-activated receptor α (PPARα) and its downstream gene expression. Knockdown of PPARα attenuated the increase in ABCA1 protein, indicating that pitavastatin increased ABCA1 protein via PPARα activation, although it repressed LXR activation. Furthermore, the degradation of ABCA1 protein was retarded in pitavastatin-treated cells. These data suggest that pitavastatin increases ABCA1 protein expression by dual mechanisms: SREBP2-mediated mRNA transcription and PPARα-mediated ABCA1 protein stabilization, but not by the PPAR-LXR-ABCA1 pathway. [Supplementary Figures: available only at http://dx.doi.org/10.1254/jphs.10241FP].

Topics: Animals; ATP Binding Cassette Transporter 1; ATP-Binding Cassette Transporters; Carcinoma, Hepatocellular; Cell Line, Tumor; Gene Expression Regulation; Genes, Reporter; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Kinetics; Liver; Liver Neoplasms; Liver X Receptors; Orphan Nuclear Receptors; PPAR alpha; Promoter Regions, Genetic; Protein Biosynthesis; Quinolines; Rats; RNA Interference; RNA, Messenger; RNA, Small Interfering; Signal Transduction; Sterol Regulatory Element Binding Proteins; Transcriptional Activation

It has been shown that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors have pleiotropic effects and that human serum paraoxonase (PON1) inhibits the oxidative modification of low-density lipoprotein. We investigated the effects of pitavastatin on PON1 gene promoter activity and PON1 protein expression through the activation of mitogen-activated protein (MAP) kinase signaling cascades in cultured Huh7 cells. Both PON1 gene promoter activity and PON1 protein expression were elevated by pitavastatin stimulation. Pitavastatin phosphorylated p44/42 MAP kinase. The effects of pitavastatin on PON1 promoter activity and PON1 protein expression were attenuated by PD98059. The cotransfection of Sp1 expression vector increased PON1 promoter activity, and mithramycin suppressed pitavastatin-enhanced PON1 promoter activity. The latter activity was attenuated by cotransfection with the expression vector of sterol regulatory element-binding protein-2 (SREBP-2) with mutated p44/42 MAP kinase specific phosphorylation sites. Pitavastatin increased the Sp1-PON1 DNA complex and this effect was attenuated by PD98059. These observations suggest that pitavastatin phosphorylates p44/42 MAP kinase and then activates the transcription of PON1 gene and increases the PON1 protein expression in Huh7 cells. Furthermore, we speculate that pitavastatin affects both the phosphorylation of SREBP-2 and the Sp1 binding to PON1 DNA through the activation of p44/42 MAP kinase signaling cascade.

Topics: Aryldialkylphosphatase; Carcinoma, Hepatocellular; Cell Line, Tumor; Enzyme Inhibitors; Gene Expression; Humans; Liver Neoplasms; MAP Kinase Signaling System; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Phosphorylation; Promoter Regions, Genetic; Quinolines; Sp1 Transcription Factor; Sterol Regulatory Element Binding Protein 2

Topics: Aminosalicylic Acids; Benzenesulfonates; Carcinoma, Hepatocellular; Humans; Liver Neoplasms; Quinolines; Signal Transduction; STAT3 Transcription Factor; Transforming Growth Factor beta

To study the apoptosis of human hepatocellular carcinoma cell line HepG 2 induced by pitavastatin (NK-104) and to investigate the change of caspase-3 activity.. HepG 2 cells were treated with NK-104 for 48 hours and observed under a microscope by using Hoechst 33258 staining. The proliferation of the cells was detected with WST-8 method. The apoptosis peaks were examined by flow cytometry. The caspase-3 activity was detected with caspase-3 colorimetric protease assay.. The treatment of HepG 2 with 10 micromol/L NK-104 could inhibit the proliferation, and induce HepG 2 apoptosis and up-regulate the caspase-3 activity.. NK-104 at 10 micromol/L induces apoptosis of HepG 2 cells. It is dependent on caspase-3 pathway in human hepatocellular carcinoma cells.

Topics: Antineoplastic Agents; Apoptosis; Carcinoma, Hepatocellular; Caspase 3; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Flow Cytometry; Humans; Liver Neoplasms; Quinolines

As nuclear factor-kappa B (NF-kappaB) is essential for promoting inflammation-associated cancer, it is a potential target for cancer prevention in chronic inflammatory diseases. Here we examined the anti-inflammatory effect of pitavastatin, a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, on NF-kappaB activated by TNF-alpha in hepatocellular carcinoma (HCC) cells. Western blot revealed that the treatment of Huh 7 cells with pitavastatin at 0.1 microM inhibited the nuclear expression of NF-kappaB p65 induced by TNF-alpha. Furthermore, electrophoretic mobility shift assay showed that after the cells were incubated with pitavastatin alone or with pitavastatin and TNF-alpha for 24 h, pitavastatin significantly decreased the DNA binding activity of NF-kappaB induced by TNF-alpha. Subsequently, luciferase assay revealed that pitavastatin suppressed the transcriptional activity of the NF-kappaB promoter, which was clearly related to the HMG-CoA reductase activity because the addition of mevalonic acid (MEV) elevated the TNF-alpha activity. Moreover, the Rho kinase inhibitor Y27632 had no major effect on the NF-kappaB inhibitory activity of pitavastatin. The inhibitory effect of pitavastatin is possibly independent of the Rho kinase pathway in inflammation-associated HCC cells is. Finally, the addition of TNF-alpha significantly increased IL-6 protein production, which was suppressed by the addition of pitavastatin. These results suggest that pitavastatin at a low dose (0.1 microM) inhibits NF-kappaB activation and decreases IL-6 production induced by TNF-alpha, and is therefore expected to be a new strategy for treating HCC.

Topics: Anti-Inflammatory Agents; Blotting, Western; Carcinoma, Hepatocellular; Cell Line, Tumor; Electrophoretic Mobility Shift Assay; Enzyme-Linked Immunosorbent Assay; Genes, Reporter; Humans; Indicators and Reagents; Interleukin-6; Intracellular Signaling Peptides and Proteins; Liver Neoplasms; Luciferases; NF-kappa B; Nuclear Proteins; Protein Serine-Threonine Kinases; Quinolines; rho-Associated Kinases; Signal Transduction; Tetrazolium Salts; Transcription, Genetic; Tumor Necrosis Factor-alpha

ATP binding cassette A1 (ABCA1) is responsible in vivo for the formation of HDL by promoting the lipidation of apoprotein A-I (apoA-I) via cholesterol and phospholipid efflux from the liver. Treatment of patients with statins produces an increase in HDL plasma level, but the underlying mechanism is not completely understood. In this work we investigated the ability of pitavastatin to modulate ABCA1-mediated efflux from Fu5AH rat hepatoma cells, that here we demonstrate to express functional ABCA1 upon treatment with 22OH/cRA. In both basal and ABCA1 expressing cells pitavastatin 0.1-50microM induced a dose-dependent increase in cholesterol efflux to apoA-I; this effect was reversed by mevalonate or geranyl geraniol. A stimulatory effect was also observed on phospholipid efflux. Similar results were obtained with compactin, suggesting a class-related effect of statins. These results indicate a potential mechanism for the improvement in HDL plasma profile observed in patients treated with statins.

Topics: Animals; ATP Binding Cassette Transporter 1; ATP-Binding Cassette Transporters; Biological Transport; Carcinoma, Hepatocellular; Cell Line, Tumor; Cholesterol; Diterpenes; Dose-Response Relationship, Drug; Enzyme Inhibitors; Humans; Lipid Metabolism; Liver Neoplasms; Mevalonic Acid; Quinolines; Rats