A novel inhibitor of the tyrosine kinase Src suppresses phosphorylation of its major cellular substrates and reduces bone resorption in vitro and in rodent models in vivo

Missbach, Martin; Jeschke, Margit; Feyen, Jean H.M.; Müller, Klaus; Glatt, Markus; Green, J; Šuša, Mira

doi:10.1016/s8756-3282(99)00020-4

Cited by 157 publications

(110 citation statements)

References 48 publications

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“…These findings obtained in normal cells are in agreement with results indicating a role of c-Src tyrosine kinase in the EGF receptor-mediated activation of Stat5 in A431 and HepG2 cells (Olayioye et al, 1999;Wang et al, 1999). We have observed that EGF induces tyrosine phosphorylation of paxillin, which may be a downstream response to c-Src (Missbach et al, 1999), and was sensitive to pharmacological inhibition of c-Src, and this effect was more pronounced in high-density cultures (data not shown). We also observed a basal tyrosine kinase activity in immunoprecipitates of c-Src from hepatocyte lysates, which was inhibited by CGP77675, but so far we have not found any significant increase of this kinase activity after EGF stimulation (data not shown).…”

Section: Discussionsupporting

confidence: 91%

“…3A and data not shown), with IC 50 at about 0.5-1 mM (Fig. 3C), which is in the same range as found for inhibition of tyrosine phosphorylation of Fak and paxillin in Src-overexpressing cells (Missbach et al, 1999).…”

Section: Constitutive Serine Phosphorylation Of Stat5bsupporting

confidence: 80%

“…Recombinant human GH was a gift from Pharmacia & Norge AS (Oslo, Norway). The Src inhibitor CGP77675, described in Missbach et al (1999); Susa et al (2000) was a gift from Novartis Pharma AG (Basel, Switzerland). Polyclonal rabbit antibodies against Stat5b (C-17, sc-835) and Stat5a (L-20, sc-1081), and EGF receptor (sc-03) were from Santa Cruz Biotechnology (Santa Cruz, CA).…”

Section: Materials and Methods Materialsmentioning

confidence: 99%

“…Src has also been reported to activate Stat5 (Kazansky et al, 1999;Reddy et al, 2000), and recent findings in A431 and HepG2 cells suggest that c-Src may be involved in EGF receptor-mediated activation of Stat5 (Olayioye et al, 1999;Wang et al, 1999), while PDGF-induced Stat5 activation was independent of c-Src and c-Fyn in some transfected cells and cell-free systems (Paukku et al, 2000). To examine the role of c-Src in the effect of EGF on Stat5b activation in the cultured hepatocytes, we preincubated the cells for 90 min with CGP77675, an inhibitor of the c-Src kinase (Missbach et al, 1999;Susa et al, 2000), prior to stimulation with an agonist. CGP77675 dose dependently inhibited EGF-induced tyrosine phosphorylation and PIE-binding activity of Stat5b (Fig.…”

Section: Constitutive Serine Phosphorylation Of Stat5bmentioning

confidence: 99%

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EGF receptor‐mediated, c‐Src‐dependent, activation of Stat5b is downregulated in mitogenically responsive hepatocytes

Guren

Ødegård

Abrahamsen

et al. 2003

Journal Cellular Physiology

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Signal transducer and activator of transcription (STAT) proteins may be activated by epidermal growth factor (EGF), but their role in EGF receptor-mediated mitogenic signaling is not clear. We previously showed that Stat5b was activated by EGF in rat hepatocytes in primary monolayer culture. In the present study, we found that EGF induced tyrosine phosphorylation of Stat5b both on Tyr-699, which correlated with specific DNA binding activity, and also on other tyrosine residues. The Src tyrosine kinase inhibitor CGP77675 blocked the EGF-induced activation of Stat5b, but did not affect the Stat5b activation by growth hormone (GH) or prolactin (PRL). The Stat5b response to EGF was most pronounced soon (3 h) after plating (early G 1 ) and at high cell density (50,000 hepatocytes per cm 2 ). However, at this cell density EGF did not stimulate DNA synthesis. In hepatocytes at 24 h of culturing (mid/late G 1 ) with 20,000 cells per cm 2 , EGF induced strong phosphorylation of the EGF receptor, as well as Shc and ERK, and stimulated DNA synthesis, but did not activate Stat5b, although the Stat5b response to GH or PRL was retained. A strong GHinduced Stat5b activation neither influenced the DNA synthesis alone nor enhanced the mitogenic effect of EGF. The results show that EGF induces tyrosine phosphorylation and DNA-binding activity of Stat5b in a manner different from GH and PRL, apparently by a Src-dependent mechanism. The data also provide further evidence that Stat5b is not required for mitogenic signaling from the EGF receptor.

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Section: Discussionsupporting

confidence: 91%

Section: Constitutive Serine Phosphorylation Of Stat5bsupporting

confidence: 80%

Section: Materials and Methods Materialsmentioning

confidence: 99%

Section: Constitutive Serine Phosphorylation Of Stat5bmentioning

confidence: 99%

See 2 more Smart Citations

EGF receptor‐mediated, c‐Src‐dependent, activation of Stat5b is downregulated in mitogenically responsive hepatocytes

Guren

Ødegård

Abrahamsen

et al. 2003

Journal Cellular Physiology

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“…Together with the findings of Felsenfeld et al (6) that the adapter function of Src promotes fibroblasts motility, these results suggest that the predominant role of Src in osteoclasts might be as an adaptor molecule, recruiting other proteins that are necessary for the modulation of integrin-cytoskeletal links, cell attachment, and migration. On the other hand, there are reports that indicate that Src kinase activity is required for normal osteoclastic bone resorption (7)(8)(9), leaving the question of the contribution of Src kinase activity unsettled.…”

mentioning

confidence: 99%

Src Kinase Activity Is Essential for Osteoclast Function

Miyazaki

Sanjay

Neff

et al. 2004

Journal of Biological Chemistry

260

288

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ATP site-directed competitive and irreversible inhibitors of protein kinases

2000

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Several tyrosine and serine/threonine protein kinases have emerged in the last few years as attractive targets in the search for new therapeutic agents being applicable in many different disease indications. Initially, inhibition of these protein kinases by ATP site‐directed inhibitors was considered less prone to success, but medicinal chemists from both academia and industry have been able to impart potency and selectivity to a limited number of scaffolds by modulating and fine‐tuning the interactions of the modified template with the ATP binding site of the selected kinase. The chemical templates that have been used in the synthesis of ATP site‐directed protein kinase inhibitors are reviewed with emphasis on the kinase inhibitors that have entered or are about to enter clinical trials. Examples have been selected to illustrate how structure‐based design approaches and new methods to increase compound diversity have had an impact on this area of research. © 2000 John Wiley & Sons, Inc. Med Res Rev, 20, No. 1, 28–57, 2000

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A novel inhibitor of the tyrosine kinase Src suppresses phosphorylation of its major cellular substrates and reduces bone resorption in vitro and in rodent models in vivo

Cited by 157 publications

References 48 publications

EGF receptor‐mediated, c‐Src‐dependent, activation of Stat5b is downregulated in mitogenically responsive hepatocytes

EGF receptor‐mediated, c‐Src‐dependent, activation of Stat5b is downregulated in mitogenically responsive hepatocytes

Src Kinase Activity Is Essential for Osteoclast Function

ATP site-directed competitive and irreversible inhibitors of protein kinases

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