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Full-Text Articles in Medical Molecular Biology
Death Receptor 5 Signaling Promotes Hepatocyte Lipoapoptosis., Sophie C. Cazanave, Justin L. Mott, Steven F. Bronk, Nathan W. Werneburg, Christian D. Fingas, X Wei Meng, Niklas Finnberg, Wafik S. El-Deiry, Scott H. Kaufmann, Gregory J. Gores
Death Receptor 5 Signaling Promotes Hepatocyte Lipoapoptosis., Sophie C. Cazanave, Justin L. Mott, Steven F. Bronk, Nathan W. Werneburg, Christian D. Fingas, X Wei Meng, Niklas Finnberg, Wafik S. El-Deiry, Scott H. Kaufmann, Gregory J. Gores
Journal Articles: Biochemistry & Molecular Biology
Nonalcoholic steatohepatitis is characterized by hepatic steatosis, elevated levels of circulating free fatty acids (FFA), endoplasmic reticulum (ER) stress, and hepatocyte lipoapoptosis. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) death receptor 5 (DR5) is significantly elevated in patients with nonalcoholic steatohepatitis, and steatotic hepatocytes demonstrate increased sensitivity to TRAIL-mediated cell death. Nonetheless, a role for TRAIL and/or DR5 in mediating lipoapoptotic pathways is unexplored. Here, we examined the contribution of DR5 death signaling to lipoapoptosis by free fatty acids. The toxic saturated free fatty acid palmitate induces an increase in DR5 mRNA and protein expression in Huh-7 human hepatoma cells leading …
The Raf/Mek/Extracellular Signal-Regulated Kinase 1/2 Pathway Can Mediate Growth Inhibitory And Differentiation Signaling Via Androgen Receptor Downregulation In Prostate Cancer Cells., Seung-Keun Hong, Jin-Hwan Kim, Ming-Fong Lin, Jong-In Park
The Raf/Mek/Extracellular Signal-Regulated Kinase 1/2 Pathway Can Mediate Growth Inhibitory And Differentiation Signaling Via Androgen Receptor Downregulation In Prostate Cancer Cells., Seung-Keun Hong, Jin-Hwan Kim, Ming-Fong Lin, Jong-In Park
Journal Articles: Biochemistry & Molecular Biology
Upregulated ERK1/2 activity is correlated with androgen receptor (AR) downregulation in certain prostate cancer (PCa) that exhibits androgen deprivation-induced neuroendocrine differentiation, but its functional relevance requires elucidation. We found that sustained ERK1/2 activation using active Raf or MEK1/2 mutants is sufficient to induce AR downregulation at mRNA and protein levels in LNCaP. Downregulation of AR protein, but not mRNA, was blocked by proteasome inhibitors, MG132 and bortezomib, indicating that the pathway regulation is mediated at multiple points. Ectopic expression of a constitutively active AR inhibited Raf/MEK/ERK-mediated regulation of the differentiation markers, neuron-specific enolase and neutral endopeptidase, and the cyclin-dependent kinase …
Hedgehog Inhibition Promotes A Switch From Type Ii To Type I Cell Death Receptor Signaling In Cancer Cells., Satoshi Kurita, Justin L. Mott, Sophie C. Cazanave, Christian D. Fingas, Maria E. Guicciardi, Steve F. Bronk, Lewis R. Roberts, Martin E. Fernandez-Zapico, Gregory J. Gores
Hedgehog Inhibition Promotes A Switch From Type Ii To Type I Cell Death Receptor Signaling In Cancer Cells., Satoshi Kurita, Justin L. Mott, Sophie C. Cazanave, Christian D. Fingas, Maria E. Guicciardi, Steve F. Bronk, Lewis R. Roberts, Martin E. Fernandez-Zapico, Gregory J. Gores
Journal Articles: Biochemistry & Molecular Biology
TRAIL is a promising therapeutic agent for human malignancies. TRAIL often requires mitochondrial dysfunction, referred to as the Type II death receptor pathway, to promote cytotoxicity. However, numerous malignant cells are TRAIL resistant due to inhibition of this mitochondrial pathway. Using cholangiocarcinoma cells as a model of TRAIL resistance, we found that Hedgehog signaling blockade sensitized these cancer cells to TRAIL cytotoxicity independent of mitochondrial dysfunction, referred to as Type I death receptor signaling. This switch in TRAIL requirement from Type II to Type I death receptor signaling was demonstrated by the lack of functional dependence on Bid/Bim and Bax/Bak, …