gdc-0449 and Liver-Neoplasms

Clinical trials have revealed that inhibition of sonic Hedgehog (SHH) signaling or histone deacetylase (HDAC) holds promise as a treatment for liver cancer. Based on our previous results, it was hypothesized that dual inhibition of SHH and HDAC may contribute to more efficient targeting of this disease. The effect of SHH inhibitor vismodegib as a single‑agent or in combination with HDAC inhibitor entinostat was evaluated by Cell Counting Kit‑8 (CCK‑8) and flow cytometric assays, as well as immunoblotting. The synergistic effect on cell viability was assessed by combination indexes. Ex vivo cultured liver cancer tissues from a patient were treated with vismodegib as a single‑agent or in combination with entinostat, and analyzed by histological and immunohistochemical methods. The results revealed that the dual use of the SHH inhibitor and the HDAC inhibitor effectively synergized to inhibit proliferation, and promote apoptosis in liver cancer cells. Furthermore, the effect of the combination of these drugs was confirmed in an ex vivo culture of human liver cancer tissue. Mechanistically, combined use of SHH and HDAC inhibitors resulted in significantly greater downregulation of SHH and PI3K/mTOR signaling. In conclusion, the combined use of SHH signaling and HDAC inhibitors may be an effective therapeutic strategy for liver cancer.

Topics: Anilides; Apoptosis; Benzamides; Cell Line, Tumor; Cell Proliferation; Cell Survival; Down-Regulation; Hedgehog Proteins; Hep G2 Cells; Histone Deacetylase Inhibitors; Histone Deacetylases; Humans; Liver Neoplasms; Middle Aged; Phosphatidylinositol 3-Kinases; Pyridines; Signal Transduction; TOR Serine-Threonine Kinases

Abnormal expression of chondroitin sulfate has been found in many types of cancer, while its biological functions in hepatocellular carcinoma (HCC) progression remain uninvestigated. Here, we report that chondroitin sulfate synthase 1 (CHSY1), the enzyme that mediates the polymerization step of chondroitin sulfate, is a critical mediator of malignant character in HCC that acts via modulating the activity of the hedgehog signaling. CHSY1 was up-regulated frequently in HCC where these events were associated with worse histologic grade and poor survival. Enforced expression of CHSY1 was sufficient to enhance cell growth, migration, invasion, and epithelial-mesenchymal transition, whereas silencing of CHSY1 suppressed these malignant phenotypes. Mechanistic investigations revealed that the increase of cell surface chondroitin sulfate by CHSY1 promoted sonic hedgehog binding and signaling. Inhibiting hedgehog pathway with vismodegib decreased CHSY1-induced migration, invasion, and lung metastasis of HCC cells, establishing the critical role of hedgehog signaling in mediating the effects of CHSY1 expression. Together, our results indicate that CHSY1 overexpression in HCC contributes to the malignant behaviors in cancer cells, we provide novel insights into the significance of chondroitin sulfate in hedgehog signaling and HCC pathogenesis.

Topics: Anilides; Animals; Carcinoma, Hepatocellular; Cell Movement; Cell Proliferation; Chondroitin Sulfates; Epithelial-Mesenchymal Transition; Female; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Glucuronosyltransferase; Hedgehog Proteins; Hep G2 Cells; Humans; Liver Neoplasms; Lung Neoplasms; Male; Mice, Inbred C57BL; Middle Aged; Multifunctional Enzymes; N-Acetylgalactosaminyltransferases; Neoplasm Grading; Neoplasm Invasiveness; Phenotype; Pyridines; RNA Interference; Signal Transduction; Transfection; Xenograft Model Antitumor Assays

On 30 January 2012, the US FDA approved vismodegib (Erivedge. Our objective was to identify evidence of hepatotoxicity with vismodegib in the FDA Adverse Event Reporting System (FAERS) in treated patients in two National Cancer Institute Comprehensive Cancer Centers.. FAERS was searched for reports dated 1 January 2009 through 31 December 2015 using terms including hedgehog pathway and vismodegib and hepatic-related terms such as liver, jaundice, and hepatitis, among others. Disproportionality analyses with estimates of proportional reporting ratio and empirical Bayesian geometric mean were conducted. A comprehensive literature review was conducted, and the clinical databases at the University of Texas MD Anderson Cancer Center and Robert H. Lurie Comprehensive Cancer Center of Northwestern University were searched.. Two cases of severe liver dysfunction were published (Common Terminology Criteria for Adverse Events [CTCAE] class III), and 94 reports of adverse events (AEs) were detected in FAERS, 35 of which were serious AEs. Safety notifications related to hepatotoxicity have not been issued by the manufacturer or the FDA, although vismodegib is listed in LiverTox and the European Medicines Agency website.. We identified a detectable safety signal for hepatotoxicity for vismodegib within 4 years of FDA approval. Vismodegib should be used in patients with severe liver disease only after careful consideration, and concomitant hepatotoxic medications should be avoided. Rapid dissemination of such safety concerns is expected to result in fewer serious hepatotoxic AEs and more optimal outcomes for patients with cancer receiving vismodegib.

Topics: Adverse Drug Reaction Reporting Systems; Anilides; Antineoplastic Agents; Chemical and Drug Induced Liver Injury; Humans; Liver; Liver Neoplasms; Pyridines; Retrospective Studies

Sorafenib leads to a survival benefit in patients with advanced hepatocellular carcinoma but its use is hampered by the occurrence of drug resistance. To investigate the molecular mechanisms involved we developed five resistant human liver cell lines in which we studied morphology, gene expression and invasive potential. The cells changed their appearance, lost E-cadherin and KRT19 and showed high expression of vimentin, indicating epithelial-to-mesenchymal transition. Resistant cells showed reduced adherent growth, became more invasive and lost liver-specific gene expression. Furthermore, following withdrawal of sorafenib, the resistant cells showed rebound growth, a phenomenon also found in patients. This cell model was further used to investigate strategies for restoration of sensitivity to sorafenib.

Topics: Anilides; Antineoplastic Agents; Cadherins; Carcinoma, Hepatocellular; Cell Line, Tumor; Chromones; Drug Resistance, Neoplasm; Epithelial-Mesenchymal Transition; Gene Expression Regulation, Neoplastic; Humans; Keratin-19; Liver Neoplasms; Morpholines; Niacinamide; Phenylurea Compounds; Proto-Oncogene Proteins c-akt; Pyridines; Sorafenib; Vimentin

Studies of the hepatitis C virus (HCV) life-cycle rely heavily on Huh7.5 cells, but the reasons why these cells are exceptionally permissive for HCV replication are not clear. Based on recent clinical observations, we hypothesized that the Hedgehog (Hh) pathway, which has not been previously associated with HCV replication, may be involved in the Huh7.5 phenotype of increased permissiveness. We tested this hypothesis by comparing levels of a variety of Hh-related cellular markers in Huh7.5 cells with the parental Huh7 cells, which are far less permissive. Here we demonstrate that Huh7.5 cells, when compared with Huh7 cells, have substantially decreased expression of epithelial markers, increased levels of mesenchymal markers, and markedly up-regulated Hh pathway activity: Shh, >100-fold, Gli1, >30-fold, Ptc, 2-fold. In Huh7.5 cells, we found that cyclopamine, an Hh pathway antagonist, reduced HCV RNA levels by 50% compared with vehicle and inactive isomer controls. Moreover, in Huh7 cells treatment with recombinant Shh ligand and SAG, both Hh pathway agonists, stimulated HCV replication by 2-fold and 4-fold, respectively. These effects were observed with both viral infections and a subgenomic replicon. Finally, we demonstrated that GDC-0449 decreased HCV RNA levels in a dose-response manner.. We have identified a relationship between HCV and Hh signaling where up-regulated pathway activity during infection promotes an environment conducive to replication. Given that Hh activity is very low in most hepatocytes, these findings may serve to further shift the model of HCV liver infection from modest widespread replication in hepatocytes to one where a subset of cells support high-level replication. These findings also introduce Hh pathway inhibitors as potential anti-HCV therapeutics.

Topics: Anilides; Antiviral Agents; Biomarkers; Carcinoma, Hepatocellular; Cell Line, Tumor; Hedgehog Proteins; Hepacivirus; Hepatitis C, Chronic; Humans; Interferon-alpha; Liver Neoplasms; Pyridines; Replicon; Signal Transduction; Up-Regulation; Virus Replication

Chronic fibrosing liver injury is a major risk factor for hepatocarcinogenesis in humans. Mice with targeted deletion of Mdr2 (the murine ortholog of MDR3) develop chronic fibrosing liver injury. Hepatocellular carcinoma (HCC) emerges spontaneously in such mice by 50-60 weeks of age, providing a model of fibrosis-associated hepatocarcinogenesis. We used Mdr2(-/-) mice to investigate the hypothesis that activation of the hedgehog (Hh) signaling pathway promotes development of both liver fibrosis and HCC.. Hepatic injury and fibrosis, Hh pathway activation, and liver progenitor populations were compared in Mdr2(-/-) mice and age-matched wild type controls. A dose finding experiment with the Hh signaling antagonist GDC-0449 was performed to optimize Hh pathway inhibition. Mice were then treated with GDC-0449 or vehicle for 9 days, and effects on liver fibrosis and tumor burden were assessed by immunohistochemistry, qRT-PCR, Western blot, and magnetic resonance imaging.. Unlike controls, Mdr2(-/-) mice consistently expressed Hh ligands and progressively accumulated Hh-responsive liver myofibroblasts and progenitors with age. Treatment of aged Mdr2-deficient mice with GDC-0449 significantly inhibited hepatic Hh activity, decreased liver myofibroblasts and progenitors, reduced liver fibrosis, promoted regression of intra-hepatic HCCs, and decreased the number of metastatic HCC without increasing mortality.. Hh pathway activation promotes liver fibrosis and hepatocarcinogenesis, and inhibiting Hh signaling safely reverses both processes even when fibrosis and HCC are advanced.

Topics: Anilides; Animals; ATP Binding Cassette Transporter, Subfamily B; ATP-Binding Cassette Sub-Family B Member 4; Carcinoma, Hepatocellular; Cell Count; Disease Models, Animal; Gene Expression Regulation, Neoplastic; Hedgehog Proteins; Hyaluronan Receptors; Liver Cirrhosis; Liver Neoplasms; Magnetic Resonance Imaging; Mice; Osteopontin; Pyridines; Recurrence; Signal Transduction; Stem Cells; Tumor Burden