Hepatology : official journal of the American Association for the Study of Liver Diseases
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Controlled Clinical Trial
Anticholestatic effects of bezafibrate in patients with primary biliary cirrhosis treated with ursodeoxycholic acid.
Bezafibrate is a widely used hypolipidemic agent and is known as a ligand of the peroxisome proliferator-activated receptors (PPARs). Recently this agent has come to be recognized as a potential anticholestatic medicine for the treatment of primary biliary cirrhosis (PBC) that does not respond sufficiently to ursodeoxycholic acid (UDCA) monotherapy. The aim of this study was to explore the anticholestatic mechanisms of bezafibrate by analyzing serum lipid biomarkers in PBC patients and by cell-based enzymatic and gene expression assays. Nineteen patients with early-stage PBC and an incomplete biochemical response to UDCA (600 mg/day) monotherapy were treated with the same dose of UDCA plus bezafibrate (400 mg/day) for 3 months. In addition to the significant improvement of serum biliary enzymes, immunoglobulin M (IgM), cholesterol, and triglyceride concentrations in patients treated with bezafibrate, reduction of 7α-hydroxy-4-cholesten-3-one (C4), a marker of bile acid synthesis, and increase of 4β-hydroxycholesterol, a marker of CYP3A4/5 activity, were observed. In vitro experiments using human hepatoma cell lines demonstrated that bezafibrate controlled the target genes of PPARα, as well as those of the pregnane X receptor (PXR); down-regulating CYP7A1, CYP27A1, and sinusoidal Na(+) /taurocholate cotransporting polypeptide (NTCP), and up-regulating CYP3A4, canalicular multidrug resistance protein 3 (MDR3), MDR1, and multidrug resistance-associated protein 2 (MRP2). ⋯ Bezafibrate is a dual PPARs/PXR agonist with potent anticholestatic efficacy in early-stage PBC patients with an incomplete biochemical response to UDCA monotherapy.
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The delivery of treatment for hepatocellular carcinoma (HCC) could be influenced by the place of HCC diagnosis (hospitalization versus outpatient), subspecialty referral following diagnosis, as well as physician and facility factors. We conducted a study to examine the effect of patient and nonpatient factors on the place of HCC diagnosis, referral, and treatment in Veterans Administration (VA) hospitals in the United States. Using the VA Hepatitis C Clinical Case Registry, we identified hepatitis C virus (HCV)-infected patients who developed HCC during 1998-2006. All cases were verified and staged according to Barcelona Clinic Liver Cancer (BCLC) criteria. The main outcomes were place of HCC diagnosis, being seen by a surgeon or oncologist, and treatment. We examined factors related to these outcomes using hierarchical logistic regression. These factors included HCC stage, HCC surveillance, physician specialty, and facility factors, in addition to risk factors, comorbidity, and liver disease indicators. Approximately 37.2% of the 1,296 patients with HCC were diagnosed during hospitalization, 31.0% were seen by a surgeon or oncologist, and 34.3% received treatment. Being seen by a surgeon or oncologist was associated with surveillance (adjusted odds ratio [aOR] = 1.47; 95% CI: 1.20-1.80) and varied by geography (1.74;1.09-2.77). Seeing a surgeon or oncologist was predictive of treatment (aOR = 1.43; 95% CI: 1.24-1.66). There was a significant increase in treatment among patients who received surveillance (aOR = 1.37; 95% CI: 1.02-1.71), were seen by gastroenterology (1.65;1.21-2.24), or were diagnosed at a transplant facility (1.48;1.15-1.90). ⋯ Approximately 40% of patients were diagnosed during hospitalization. Most patients were not seen by a surgeon or oncologist for treatment evaluation and only 34% received treatment. Only receipt of HCC surveillance was associated with increased likelihood of outpatient diagnosis, being seen by a surgeon or oncologist, and treatment.
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The increasing incidence of hepatocellular carcinoma (HCC) is of great concern not only in the United States but throughout the world. Although sorafenib, a multikinase inhibitor with antiangiogenic and antiproliferative effects, currently sets the new standard for advanced HCC, tumor response rates are usually quite low. An understanding of the underlying mechanisms for sorafenib resistance is critical if outcomes are to be improved. In this study we tested the hypothesis that hypoxia caused by the antiangiogenic effects of sustained sorafenib therapy could induce sorafenib resistance as a cytoprotective adaptive response, thereby limiting sorafenib efficiency. We found that HCCs, clinically resistant to sorafenib, exhibit increased intratumor hypoxia compared with HCCs before treatment or HCCs sensitive to sorafenib. Hypoxia protected HCC cells against sorafenib and hypoxia-inducible factor 1 (HIF-1α) was required for the process. HCC cells acquired increased P-gp expression, enhanced glycolytic metabolism, and increased nuclear factor kappa B (NF-κB) activity under hypoxia. EF24, a molecule having structural similarity to curcumin, could synergistically enhance the antitumor effects of sorafenib and overcome sorafenib resistance through inhibiting HIF-1α by sequestering it in cytoplasm and promoting degradation by way of up-regulating Von Hippel-Lindau tumor suppressor (VHL). Furthermore, we found that sustained sorafenib therapy led to increased intratumor hypoxia, which was associated with sorafenib sensitivity in HCC subcutaneous mice tumor models. The combination of EF24 and sorafenib showed synergistically effects against metastasis both in vivo and in vitro. Synergistic tumor growth inhibition effects were also observed in subcutaneous and orthotopic hepatic tumors. ⋯ Hypoxia induced by sustained sorafenib treatment confers sorafenib resistance to HCC through HIF-1α and NF-κB activation. EF24 overcomes sorafenib resistance through VHL-dependent HIF-1α degradation and NF-κB inactivation. EF24 in combination with sorafenib represents a promising strategy for HCC.