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Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Inflammation Mediated By Jnk In Myeloid Cells Promotes The Development Of Hepatitis And Hepatocellular Carcinoma, Myoung Souk Han, Tamera Barrett, Michael A. Brehm, Roger J. Davis Apr 2016

Inflammation Mediated By Jnk In Myeloid Cells Promotes The Development Of Hepatitis And Hepatocellular Carcinoma, Myoung Souk Han, Tamera Barrett, Michael A. Brehm, Roger J. Davis

Davis Lab Publications

The cJun NH2-terminal kinase (JNK) signaling pathway is required for the development of hepatitis and hepatocellular carcinoma. A role for JNK in liver parenchymal cells has been proposed, but more recent studies have implicated non-parenchymal liver cells as the relevant site of JNK signaling. Here, we tested the hypothesis that myeloid cells mediate this function of JNK. We show that mice with myeloid cell-specific JNK deficiency exhibit reduced hepatic inflammation and suppression of both hepatitis and hepatocellular carcinoma. These data identify myeloid cells as a site of pro-inflammatory signaling by JNK that can promote liver pathology. Targeting myeloid cells with ...


The Role Of Jnk In The Development Of Hepatocellular Carcinoma, Madhumita Das, David S. Garlick, Dale Greiner, Roger J. Davis Mar 2011

The Role Of Jnk In The Development Of Hepatocellular Carcinoma, Madhumita Das, David S. Garlick, Dale Greiner, Roger J. Davis

Davis Lab Publications

The cJun NH(2)-terminal kinase (JNK) signal transduction pathway has been implicated in the growth of carcinogen-induced hepatocellular carcinoma. However, the mechanism that accounts for JNK-regulated tumor growth is unclear. Here we demonstrate that compound deficiency of the two ubiquitously expressed JNK isoforms (JNK1 and JNK2) in hepatocytes does not prevent hepatocellular carcinoma development. Indeed, JNK deficiency in hepatocytes increased the tumor burden. In contrast, compound JNK deficiency in hepatocytes and nonparenchymal cells reduced both hepatic inflammation and tumorigenesis. These data indicate that JNK plays a dual role in the development of hepatocellular carcinoma. JNK promotes an inflammatory hepatic ...


Defects In Death-Inducing Signalling Complex Formation Prevent Jnk Activation And Fas-Mediated Apoptosis In Du 145 Prostate Carcinoma Cells, James Curtin, Thomas Cotter Nov 2003

Defects In Death-Inducing Signalling Complex Formation Prevent Jnk Activation And Fas-Mediated Apoptosis In Du 145 Prostate Carcinoma Cells, James Curtin, Thomas Cotter

Articles

Androgen-independent prostate carcinomas are resistant to chemotherapy and cell lines derived from androgen-independent prostate carcinomas such as DU 145 cells are highly resistant to Fas-mediated apoptosis. The incubation of DU 145 cells with anti-Fas IgM agonistic antibody of Fas receptor fails to activate JNK, a stress kinase involved in regulating apoptosis. We have previously shown that JNK activation is sufficient and necessary to promote Fas-mediated apoptosis in DU 145 cells. We investigate the mechanisms by which JNK activation and apoptosis are abrogated. HSP27 is overexpressed in DU 145 cells and has previously been reported to sequester DAXX and prevent JNK ...


Anisomycin Activates Jnk And Sensitises Du 145 Prostate Carcinoma Cells To Fas Mediated Apoptosis, James Curtin, Thomas Cotter Nov 2002

Anisomycin Activates Jnk And Sensitises Du 145 Prostate Carcinoma Cells To Fas Mediated Apoptosis, James Curtin, Thomas Cotter

Articles

Treatment of the hormone refractory prostate cancer cell line DU 145 with sublethal concentrations of chemotherapeutic drugs has been reported to sensitise these cells to Fas mediated apoptosis. However, the mechanism by which this occurs has not been determined. Our group has shown that inhibition of JNK activity completely abrogates the effects of chemotherapeutic drugs. Using anisomycin, a potent JNK agonist, we have demonstrated a role for JNK in Fas mediated apoptosis in DU 145 cells. Inhibition of Caspase 8 and Caspase 9 completely inhibits this process which suggests that DU 145 cells require mitochondrial amplification of the Fas apoptotic ...