Roles of p38 MAPKs in invasion and metastasis

2012 ◽  
Vol 40 (1) ◽  
pp. 79-84 ◽  
Author(s):  
Ivan del Barco Barrantes ◽  
Angel R. Nebreda

Cells from primary tumours need to go through several steps to become fully metastatic. During this process, cancer cells acquire the ability to invade, migrate across the surrounding tissue, enter into the circulation and colonize distant organs. In the present paper, we review recent progress in understanding how the p38 MAPK (mitogen-activated protein kinase) signalling pathway participates in the different steps of metastasis. Experimental evidence suggests that tumour cells need to modulate p38 MAPK activity levels to successfully metastasize.

2001 ◽  
Vol 280 (5) ◽  
pp. H1970-H1981 ◽  
Author(s):  
Cherry Ballard-Croft ◽  
D. Jean White ◽  
David L. Maass ◽  
Dixie Peters Hybki ◽  
Jureta W. Horton

This study examined the hypothesis that burn trauma promotes cardiac myocyte secretion of inflammatory cytokines such as tumor necrosis factor (TNF)-α and produces cardiac contractile dysfunction via the p38 mitogen-activated protein kinase (MAPK) pathway. Sprague-Dawley rats were divided into four groups: 1) sham burn rats given anesthesia alone, 2) sham burn rats given the p38 MAPK inhibitor SB203580 (6 mg/kg po, 15 min; 6- and 22-h postburn), 3) rats given third-degree burns over 40% total body surface area and treated with vehicle (1 ml of saline) plus lactated Ringer solution for resuscitation (4 ml · kg−1 · percent burn−1), and 4) burn rats given injury and fluid resuscitation plus SB203580. Rats from each group were killed at several times postburn to examine p38 MAPK activity (by Western blot analysis or in vitro kinase assay); myocardial function and myocyte secretion of TNF-α were examined at 24-h postburn. These studies showed significant activation of p38 MAPK at 1-, 2-, and 4-h postburn compared with time-matched shams. Burn trauma impaired cardiac mechanical performance and promoted myocyte secretion of TNF-α. SB203580 inhibited p38 MAPK activity, reduced myocyte secretion of TNF-α, and prevented burn-mediated cardiac deficits. These data suggest p38 MAPK activation is one aspect of the signaling cascade that culminates in postburn secretion of TNF-α and contributes to postburn cardiac dysfunction.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Carol O’Callaghan ◽  
Liam J. Fanning ◽  
Orla P. Barry

p38δmitogen activated protein kinase (MAPK) is a unique stress responsive protein kinase. While the p38 MAPK family as a whole has been implicated in a wide variety of biological processes, a specific role for p38δMAPK in cellular signalling and its contribution to both physiological and pathological conditions are presently lacking. Recent emerging evidence, however, provides some insights into specific p38δMAPK signalling. Importantly, these studies have helped to highlight functional similarities as well as differences between p38δMAPK and the other members of the p38 MAPK family of kinases. In this review we discuss the current understanding of the molecular mechanisms underlying p38δMAPK activity. We outline a role for p38δMAPK in important cellular processes such as differentiation and apoptosis as well as pathological conditions such as neurodegenerative disorders, diabetes, and inflammatory disease. Interestingly, disparate roles for p38δMAPK in tumour development have also recently been reported. Thus, we consider evidence which characterises p38δMAPK as both a tumour promoter and a tumour suppressor. In summary, while our knowledge of p38δMAPK has progressed somewhat since its identification in 1997, our understanding of this particular isoform in many cellular processes still strikingly lags behind that of its counterparts.


2002 ◽  
Vol 362 (2) ◽  
pp. 367-373 ◽  
Author(s):  
Béatrice THOMAS ◽  
Sylvie THIRION ◽  
Lydie HUMBERT ◽  
Lujian TAN ◽  
Mary B. GOLDRING ◽  
...  

Chondrocyte dedifferentiation has been noted in osteoarthritic cartilage, but the contribution of this phenomenon is poorly understood. Interleukin (IL)-1β, the major pro-inflammatory cytokine found in osteoarthritic synovial fluid, induces the dedifferentiation of cultured articular chondrocytes, whereas E-series prostaglandins (PGE) are capable of inducing cell differentiation. Since PGE2 synthesis is up-regulated by IL-1β, we addressed the question of whether the state of chondrocyte differentiation may influence the production of IL-1-induced PGE2 by modulating cyclooxygenase (COX)-2 expression. Immortalized human articular chondrocytes, (tsT/AC62) cultured in monolayer after passage through alginate matrix (alg+) produced 5-fold greater amounts of PGE2 than continuous monolayer cultures (alg-) after stimulation with IL-1β. Moreover, IL-1β induced COX-2 expression at 0.01ng/ml in (alg+) cells, whereas a 100-fold higher dose of cytokine was necessary for stimulation in (alg-) cells. SB203580, a selective p38 mitogen-activated protein kinase (MAPK) inhibitor, completely abolished the IL-1β-induced COX-2 mRNA. Overexpression of p38 MAPK induces a COX-2 reporter, whereas overexpression of dominant negative p38 MAPK represses IL-1β-induced promoter expression. Interestingly, IL-1β-induced p38 MAPK activity was greatly enhanced in (alg+) compared with (alg-) cells. Our results suggest that differentiated articular chondrocytes are highly responsive to IL-1β and that p38 MAPK mediates this response by inducing COX-2 gene expression.


2001 ◽  
Vol 276 (50) ◽  
pp. 46792-46797 ◽  
Author(s):  
Paul H. Driggers ◽  
James H. Segars ◽  
Domenica M. Rubino

The estrogen receptors (ERs) are ligand-inducible transcription factors that play key roles in the control of growth and differentiation in reproductive tissues. We showed that the novel Dbl family proto-oncoprotein Brx enhances ligand-dependent activity of ERα via a Cdc42-dependent pathway. Brx also significantly enhances ligand-dependent activity of ERβ. This enhancement is not affected by inhibition of p44/42 mitogen-activated protein kinase (MAPK) activation by PD98059. However, addition of the p38 MAPK inhibitor SB202190 abrogates the enhancement of ERβ activity by Brx, showing that p38 MAPK activity is required for the enhancement of ERβ function by Brx. In COS-7 cells, transfection of Brx leads to activation of endogenous p38 MAPK activity. Co-expression of the β2 isoform of human p38 MAPK and a constitutively active form of the p38 MAPK kinase MKK6 (MKK6-EE) synergistically augments ligand-dependent activity of ERβ. Our findings suggest that p38 MAPKs may be important regulators of ERβ activity.


Blood ◽  
2000 ◽  
Vol 95 (4) ◽  
pp. 1356-1361 ◽  
Author(s):  
Edgar Fernández

Activation of the p38 mitogen-activated protein kinase (MAPK) pathway is important for some T-cell functions, but its role in intrathymic development is unclear. To investigate the function of p38 MAPK during the late stages of thymocyte differentiation, pharmacologic and genetic manipulations were used to inhibit p38 MAPK activity in developing thymocytes. Ligation of the T-cell antigen receptor (TCR) on either thymocytes or a thymocyte cell line resulted in p38 MAPK activation. Selective pharmacologic inhibition of p38 MAPK activity with the pyridinyl imidazole drug SB203580 severely impaired the development of mature CD4+ and CD8+ single positive (SP) thymocytes from their CD4+CD8+ double positive (DP) precursors in fetal thymic organ culture (FTOC). Further, pharmacologic or genetic suppression of p38 MAPK activity, the latter achieved by overexpressing a catalytically inactive p38 MAPK, resulted in a blockade of the DP-to-SP transition of a thymocyte cell line in a novel in vitro differentiation assay. Taken together, these data constitute the first demonstration that p38 MAPK plays a critical role in the DP-to-SP differentiation of thymocytes during late intrathymic development.


Blood ◽  
1997 ◽  
Vol 89 (1) ◽  
pp. 227-234 ◽  
Author(s):  
Dharminder Chauhan ◽  
Surender Kharbanda ◽  
Atsushi Ogata ◽  
Mitsuyoshi Urashima ◽  
Gerrard Teoh ◽  
...  

Abstract Fas belongs to the family of type-1 membrane proteins that transduce apoptotic signals. In the present studies, we characterized signaling during Fas-induced apoptosis in RPMI-8226 and IM-9 multiple myeloma (MM) derived cell lines as well as patient plasma cell leukemia cells. Treatment with anti-Fas (7C11) monoclonal antibody (MoAb) induced apoptosis, evidenced by internucleosomal DNA fragmentation and propidium iodide staining, and was associated with increased expression of c-jun early response gene. We also show that anti-Fas MoAb treatment is associated with activation of stress-activated protein kinase (SAPK) and p38 mitogen-activated protein kinase (MAPK); however, no detectable increase in extracellular signal-regulated kinases (ERK1 and ERK2) activity was observed. Because interleukin-6 (IL-6) is a growth factor for MM cells and inhibits apoptosis induced by dexamethasone and serum starvation, we examined whether IL-6 affects anti-Fas MoAb-induced apoptosis and activation of SAPK or p38 MAPK in MM cells. Culture of MM cells with IL-6 before treatment with anti-Fas MoAb significantly reduced both DNA fragmentation and activation of SAPK, without altering induction of p38 MAPK activity. These results therefore suggest that anti-Fas MoAb-induced apoptosis in MM cells is associated with activation of SAPK, and that IL-6 may both inhibit apoptosis and modulate SAPK activity.


2007 ◽  
Vol 403 (3) ◽  
pp. 451-461 ◽  
Author(s):  
Sandrine Pacquelet ◽  
Jennifer L. Johnson ◽  
Beverly A. Ellis ◽  
Agnieszka A. Brzezinska ◽  
William S. Lane ◽  
...  

Exposure of neutrophils to LPS (lipopolysaccharide) triggers their oxidative response. However, the relationship between the signalling downstream of TLR4 (Toll-like receptor 4) after LPS stimulation and the activation of the oxidase remains elusive. Phosphorylation of the cytosolic factor p47phox is essential for activation of the NADPH oxidase. In the present study, we examined the hypothesis that IRAK-4 (interleukin-1 receptor-associated kinase-4), the main regulatory kinase downstream of TLR4 activation, regulates the NADPH oxidase through phosphorylation of p47phox. We show that p47phox is a substrate for IRAK-4. Unlike PKC (protein kinase C), IRAK-4 phosphorylates p47phox not only at serine residues, but also at threonine residues. Target residues were identified by tandem MS, revealing a novel threonine-rich regulatory domain. We also show that p47phox is phosphorylated in granulocytes in response to LPS stimulation. LPS-dependent phosphorylation of p47phox was enhanced by the inhibition of p38 MAPK (mitogen-activated protein kinase), confirming that the kinase operates upstream of p38 MAPK. IRAK-4-phosphorylated p47phox activated the NADPH oxidase in a cell-free system, and IRAK-4 overexpression increased NADPH oxidase activity in response to LPS. We have shown that endogenous IRAK-4 interacts with p47phox and they co-localize at the plasma membrane after LPS stimulation, using immunoprecipitation assays and immunofluorescence microscopy respectively. IRAK-4 was activated in neutrophils in response to LPS stimulation. We found that Thr133, Ser288 and Thr356, targets for IRAK-4 phosphorylation in vitro, are also phosphorylated in endogenous p47phox after LPS stimulation. We conclude that IRAK-4 phosphorylates p47phox and regulates NADPH oxidase activation after LPS stimulation.


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