RGD Reference Report - The inhibition of the epidermal growth factor (EGF) pathway enhances TGF-beta-induced apoptosis in rat hepatoma cells through inducing oxidative stress coincident with a change in the expression pattern of the NADPH oxidases (NOX) isoforms. - Rat Genome Database

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The inhibition of the epidermal growth factor (EGF) pathway enhances TGF-beta-induced apoptosis in rat hepatoma cells through inducing oxidative stress coincident with a change in the expression pattern of the NADPH oxidases (NOX) isoforms.

Authors: Sancho, P  Bertran, E  Caja, L  Carmona-Cuenca, I  Murillo, MM  Fabregat, I 
Citation: Sancho P, etal., Biochim Biophys Acta. 2009 Feb;1793(2):253-63. Epub 2008 Sep 24.
RGD ID: 2324662
Pubmed: PMID:18848961   (View Abstract at PubMed)
DOI: DOI:10.1016/j.bbamcr.2008.09.003   (Journal Full-text)

Transforming growth factor-beta (TGF-beta) induces apoptosis in hepatocytes, through a mechanism mediated by reactive oxygen species (ROS) production. Numerous tumoral cells develop mechanisms to escape from the TGF-beta-induced tumor suppressor effects. In this work we show that in FaO rat hepatoma cells inhibition of the epidermal growth factor receptor (EGFR) with the tyrphostin AG1478 enhances TGF-beta-induced cell death, coincident with an elevated increase in ROS production and GSH depletion. These events correlate with down-regulation of genes involved in the maintenance of redox homeostasis, such as gamma-GCS and MnSOD, and elevated mitochondrial ROS. Nonetheless, not all the ROS proceed from the mitochondria. Emerging evidences indicate that ROS production by TGF-beta is also mediated by the NADPH oxidase (NOX) system. TGF-beta-treated FaO cells induce nox1 expression. However, the treatment with TGF-beta and AG1478 greatly enhanced the expression of another family member: nox4. NOX1 and NOX4 targeted knock-down by siRNA experiments suggest that they play opposite roles, because NOX1 knockdown increases caspase-3 activity and cell death, whilst NOX4 knock-down attenuates the apoptotic process. This attenuation correlates with maintenance of GSH and antioxidant enzymes levels. In summary, EGFR inhibition enhances apoptosis induced by TGF-beta in FaO rat hepatoma cells through an increased oxidative stress coincident with a change in the expression pattern of NOX enzymes.

Gene Ontology Annotations    Click to see Annotation Detail View

Biological Process
TermQualifierEvidenceWithReferenceNotesSourceOriginal Reference(s)
positive regulation of apoptotic process  IMP 2324662 RGD 

Objects Annotated

Genes (Rattus norvegicus)
Nox4  (NADPH oxidase 4)


Additional Information