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Protein kinase C-dependent and -independent pathways of signal transduction in prostate cancer cells: fibroblast growth factor utilization of a protein kinase C-independent pathway.
Cell Growth Differ. 1995 Sep; 6(9):1129-42.CG

Abstract

To examine the possibility that differences in protein tyrosine phosphorylation contributed to differences in fibroblast growth factor (FGF) responsiveness of clonally derived C3 (modestly responsive) and T5 (highly responsive) rat prostate cancer cells, we evaluated the ability of orthovanadate to affect prostate cancer cell thymidine incorporation. These analyses showed that C3 cell FGF insensitivity was not attributable to enhanced protein phosphotyrosine phosphatase activity. Analyses of acidic FGF (aFGF)-mediated protein phosphorylation showed mitogen-caused, time-dependent tyrosine phosphorylation of C3 and T5 cell FGF receptors (FGFRs) and other proteins having a mass of 190, 150, 120, 100, 90, 80, 74, 60/62, 50, 42, or 28 kilodaltons. Although marked differences characterized aFGF mediated intensity of tyrosine phosphorylation, the notable commonality of tyrosine phosphorylation and the mass of the phosphorylated proteins suggested that C3 and T5 cells may use the ras and/or protein kinase C (PKC) pathways for FGF-mediated signal transduction. The PKC agonist 12-O-tetradecanoyl-phorbol-13-acetate (TPA) caused concentration-dependent increases in T5 cell thymidine incorporation. In contrast, TPA did not enhance thymidine incorporation of C3 cells or mitogen-sensitive NRK cells included as a nonneoplastic control. TPA also significantly enhanced T5 cell proliferation, whereas identical treatment did not affect proliferation of either C3 or NRK cells. Either 12 or 24 h treatment with 200 or 2000 ng/ml TPA caused complete PKC alpha and partial PKC delta down-regulation in C3, T5, and NRK cells. Consequently, the failure of TPA to affect C3 or NRK cell thymidine incorporation or proliferation was not attributable to potential TPA ineffectiveness in these cells. Survey immunological analyses showed that all three cell lines lacked PKC beta, PKC eta, and PKC theta. In contrast, T5 cells contained abundant amounts of PKC epsilon, whereas the PKC epsilon content of C3 and NRK cells was near the limit of detection. TPA treatment of T5 cells evoked only partial PKC epsilon down-regulation. Both aFGF and basic FGF (bFGF) promoted concentration-dependent enhancement of TPA-pretreated T5 cell thymidine incorporation, and the effects of combined TPA and either aFGF or bFGF treatment were additive. Neither aFGF nor bFGF was able to enhance thymidine incorporation of TPA-pretreated C3 cells beyond the modest effects elicited by FGF treatment of C3 controls.(

ABSTRACT

TRUNCATED AT 250 WORDS)

Authors+Show Affiliations

Department of Obstetrics and Gynecology, University of Texas Health Science Center at San Antonio 78284-7836, USA.No affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

8519690

Citation

Hrzenjak, M, and S A. Shain. "Protein Kinase C-dependent and -independent Pathways of Signal Transduction in Prostate Cancer Cells: Fibroblast Growth Factor Utilization of a Protein Kinase C-independent Pathway." Cell Growth & Differentiation : the Molecular Biology Journal of the American Association for Cancer Research, vol. 6, no. 9, 1995, pp. 1129-42.
Hrzenjak M, Shain SA. Protein kinase C-dependent and -independent pathways of signal transduction in prostate cancer cells: fibroblast growth factor utilization of a protein kinase C-independent pathway. Cell Growth Differ. 1995;6(9):1129-42.
Hrzenjak, M., & Shain, S. A. (1995). Protein kinase C-dependent and -independent pathways of signal transduction in prostate cancer cells: fibroblast growth factor utilization of a protein kinase C-independent pathway. Cell Growth & Differentiation : the Molecular Biology Journal of the American Association for Cancer Research, 6(9), 1129-42.
Hrzenjak M, Shain SA. Protein Kinase C-dependent and -independent Pathways of Signal Transduction in Prostate Cancer Cells: Fibroblast Growth Factor Utilization of a Protein Kinase C-independent Pathway. Cell Growth Differ. 1995;6(9):1129-42. PubMed PMID: 8519690.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Protein kinase C-dependent and -independent pathways of signal transduction in prostate cancer cells: fibroblast growth factor utilization of a protein kinase C-independent pathway. AU - Hrzenjak,M, AU - Shain,S A, PY - 1995/9/1/pubmed PY - 1995/9/1/medline PY - 1995/9/1/entrez SP - 1129 EP - 42 JF - Cell growth & differentiation : the molecular biology journal of the American Association for Cancer Research JO - Cell Growth Differ VL - 6 IS - 9 N2 - To examine the possibility that differences in protein tyrosine phosphorylation contributed to differences in fibroblast growth factor (FGF) responsiveness of clonally derived C3 (modestly responsive) and T5 (highly responsive) rat prostate cancer cells, we evaluated the ability of orthovanadate to affect prostate cancer cell thymidine incorporation. These analyses showed that C3 cell FGF insensitivity was not attributable to enhanced protein phosphotyrosine phosphatase activity. Analyses of acidic FGF (aFGF)-mediated protein phosphorylation showed mitogen-caused, time-dependent tyrosine phosphorylation of C3 and T5 cell FGF receptors (FGFRs) and other proteins having a mass of 190, 150, 120, 100, 90, 80, 74, 60/62, 50, 42, or 28 kilodaltons. Although marked differences characterized aFGF mediated intensity of tyrosine phosphorylation, the notable commonality of tyrosine phosphorylation and the mass of the phosphorylated proteins suggested that C3 and T5 cells may use the ras and/or protein kinase C (PKC) pathways for FGF-mediated signal transduction. The PKC agonist 12-O-tetradecanoyl-phorbol-13-acetate (TPA) caused concentration-dependent increases in T5 cell thymidine incorporation. In contrast, TPA did not enhance thymidine incorporation of C3 cells or mitogen-sensitive NRK cells included as a nonneoplastic control. TPA also significantly enhanced T5 cell proliferation, whereas identical treatment did not affect proliferation of either C3 or NRK cells. Either 12 or 24 h treatment with 200 or 2000 ng/ml TPA caused complete PKC alpha and partial PKC delta down-regulation in C3, T5, and NRK cells. Consequently, the failure of TPA to affect C3 or NRK cell thymidine incorporation or proliferation was not attributable to potential TPA ineffectiveness in these cells. Survey immunological analyses showed that all three cell lines lacked PKC beta, PKC eta, and PKC theta. In contrast, T5 cells contained abundant amounts of PKC epsilon, whereas the PKC epsilon content of C3 and NRK cells was near the limit of detection. TPA treatment of T5 cells evoked only partial PKC epsilon down-regulation. Both aFGF and basic FGF (bFGF) promoted concentration-dependent enhancement of TPA-pretreated T5 cell thymidine incorporation, and the effects of combined TPA and either aFGF or bFGF treatment were additive. Neither aFGF nor bFGF was able to enhance thymidine incorporation of TPA-pretreated C3 cells beyond the modest effects elicited by FGF treatment of C3 controls.(ABSTRACT TRUNCATED AT 250 WORDS) SN - 1044-9523 UR - https://www.unboundmedicine.com/medline/citation/8519690/Protein_kinase_C_dependent_and__independent_pathways_of_signal_transduction_in_prostate_cancer_cells:_fibroblast_growth_factor_utilization_of_a_protein_kinase_C_independent_pathway_ L2 - http://cgd.aacrjournals.org/cgi/pmidlookup?view=long&pmid=8519690 DB - PRIME DP - Unbound Medicine ER -