File Download
  Links for fulltext
     (May Require Subscription)
Supplementary

Article: Protein kinase G type Iα activity in human ovarian cancer cells significantly contributes to enhanced Src activation and DNA synthesis/cell proliferation

TitleProtein kinase G type Iα activity in human ovarian cancer cells significantly contributes to enhanced Src activation and DNA synthesis/cell proliferation
Authors
Issue Date2010
PublisherAmerican Association for Cancer Research. The Journal's web site is located at http://mcr.aacrjournals.org/
Citation
Molecular Cancer Research, 2010, v. 8 n. 4, p. 578-591 How to Cite?
AbstractPreviously, we showed that basal activity of nitric oxide (NO)/cyclic GMP (cGMP)/protein kinase G (PKG) signaling pathway protects against spontaneous apoptosis and confers resistance to cisplatin-induced apoptosis in human ovarian cancer cells. The present study determines whether basal PKG kinase activity regulates Src family kinase (SFK) activity and proliferation in these cells. PKG-Iα was identified as predominant isoform in both OV2008 (cisplatin-sensitive, wild-type p53) and A2780cp (cisplatin-resistant, mutated p53) ovarian cancer cells. In both cell lines, ODQ (inhibitor of endogenous NO-induced cGMP biosynthesis), DT-2 (highly specific inhibitor of PKG-Iα kinase activity), and PKG-Iα knockdown (using small interfering RNA) caused concentration-dependent inhibition of DNA synthesis (assessed by bromodeoxyuridine incorporation), indicating an important role of basal cGMP/PKG-Iα kinase activity in promoting cell proliferation. DNA synthesis in OV2008 cells was dependent on SFK activity, determined using highly selective SFK inhibitor, 4-(4′-phenoxyanilino)-6,7-dimethoxyquinazoline (SKI-1). Studies using DT-2 and PKG-Iα small interfering RNA revealed that SFK activity was dependent on PKG-Iα kinase activity. Furthermore, SFK activity contributed to endogenous tyrosine phosphorylation of PKG-Iα in OV2008 and A2780cp cells. In vitro coincubation of recombinant human c-Src and PKG-Iα resulted in c-Src–mediated tyrosine phosphorylation of PKG-Iα and enhanced c-Src autophosphorylation/activation, suggesting that human c-Src directly tyrosine phosphorylates PKG-Iα and the c-Src/PKG-Iα interaction enhances Src kinase activity. Epidermal growth factor–induced stimulation of SFK activity in OV2008 cells increased PKG-Iα kinase activity (indicated by Ser239 phosphorylation of the PKG substrate vasodilator-stimulated phosphoprotein), which was blocked by both SKI-1 and SU6656. The data suggest an important role of Src/PKG-Iα interaction in promoting DNA synthesis/cell proliferation in human ovarian cancer cells. The NO/cGMP/PKG-Iα signaling pathway may provide a novel therapeutic target for disrupting ovarian cancer cell proliferation. Mol Cancer Res; 8(4); 578–91. ©2010 AACR.
Persistent Identifierhttp://hdl.handle.net/10722/208087
ISSN
2015 Impact Factor: 4.51
2015 SCImago Journal Rankings: 2.534

 

DC FieldValueLanguage
dc.contributor.authorLeung, ELH-
dc.contributor.authorWong, JC-
dc.contributor.authorJohlfs, MG-
dc.contributor.authorTsang, BK-
dc.contributor.authorFiscus, RR-
dc.date.accessioned2015-02-10T07:49:51Z-
dc.date.available2015-02-10T07:49:51Z-
dc.date.issued2010-
dc.identifier.citationMolecular Cancer Research, 2010, v. 8 n. 4, p. 578-591-
dc.identifier.issn1541-7786-
dc.identifier.urihttp://hdl.handle.net/10722/208087-
dc.description.abstractPreviously, we showed that basal activity of nitric oxide (NO)/cyclic GMP (cGMP)/protein kinase G (PKG) signaling pathway protects against spontaneous apoptosis and confers resistance to cisplatin-induced apoptosis in human ovarian cancer cells. The present study determines whether basal PKG kinase activity regulates Src family kinase (SFK) activity and proliferation in these cells. PKG-Iα was identified as predominant isoform in both OV2008 (cisplatin-sensitive, wild-type p53) and A2780cp (cisplatin-resistant, mutated p53) ovarian cancer cells. In both cell lines, ODQ (inhibitor of endogenous NO-induced cGMP biosynthesis), DT-2 (highly specific inhibitor of PKG-Iα kinase activity), and PKG-Iα knockdown (using small interfering RNA) caused concentration-dependent inhibition of DNA synthesis (assessed by bromodeoxyuridine incorporation), indicating an important role of basal cGMP/PKG-Iα kinase activity in promoting cell proliferation. DNA synthesis in OV2008 cells was dependent on SFK activity, determined using highly selective SFK inhibitor, 4-(4′-phenoxyanilino)-6,7-dimethoxyquinazoline (SKI-1). Studies using DT-2 and PKG-Iα small interfering RNA revealed that SFK activity was dependent on PKG-Iα kinase activity. Furthermore, SFK activity contributed to endogenous tyrosine phosphorylation of PKG-Iα in OV2008 and A2780cp cells. In vitro coincubation of recombinant human c-Src and PKG-Iα resulted in c-Src–mediated tyrosine phosphorylation of PKG-Iα and enhanced c-Src autophosphorylation/activation, suggesting that human c-Src directly tyrosine phosphorylates PKG-Iα and the c-Src/PKG-Iα interaction enhances Src kinase activity. Epidermal growth factor–induced stimulation of SFK activity in OV2008 cells increased PKG-Iα kinase activity (indicated by Ser239 phosphorylation of the PKG substrate vasodilator-stimulated phosphoprotein), which was blocked by both SKI-1 and SU6656. The data suggest an important role of Src/PKG-Iα interaction in promoting DNA synthesis/cell proliferation in human ovarian cancer cells. The NO/cGMP/PKG-Iα signaling pathway may provide a novel therapeutic target for disrupting ovarian cancer cell proliferation. Mol Cancer Res; 8(4); 578–91. ©2010 AACR.-
dc.languageeng-
dc.publisherAmerican Association for Cancer Research. The Journal's web site is located at http://mcr.aacrjournals.org/-
dc.relation.ispartofMolecular Cancer Research-
dc.subject.meshCarcinoma - enzymology - genetics-
dc.subject.meshCyclic GMP-Dependent Protein Kinases - antagonists & inhibitors - genetics - metabolism-
dc.subject.meshDNA Replication - genetics-
dc.subject.meshOvarian Neoplasms - enzymology - genetics-
dc.subject.meshProtein-Tyrosine Kinases - antagonists & inhibitors - genetics - metabolism-
dc.titleProtein kinase G type Iα activity in human ovarian cancer cells significantly contributes to enhanced Src activation and DNA synthesis/cell proliferationen_US
dc.typeArticleen_US
dc.identifier.emailLeung, ELH: eleung@pathology.hku.hk-
dc.description.naturelink_to_OA_fulltext-
dc.identifier.doi10.1158/1541-7786.MCR-09-0178-
dc.identifier.pmid20371672-
dc.identifier.hkuros171440-
dc.identifier.volume8-
dc.identifier.issue4-
dc.identifier.spage578-
dc.identifier.epage591-
dc.publisher.placeUnited States-

Export via OAI-PMH Interface in XML Formats


OR


Export to Other Non-XML Formats