Role of protein kinase C isoforms in phorbol ester-induced vascular endothelial growth factor expression in human glioblastoma cells

Shu Ching Shih, Andrew Mullen, Kristin Abrams, Debabrata Mukhopadhyay, Kevin P. Claffey

Research output: Contribution to journalArticle

83 Citations (Scopus)

Abstract

Aberrant expression of the potent angiogenic cytokine, vascular endothelial growth factor (VEGF), has been demonstrated to be associated with most human solid tumors. Both transcriptional and post-transcriptional mechanisms have been shown to modulate VEGF expression in a multitude of cell types. Here we report that when protein kinase C (PKC) pathways were activated in human glioblastoma U373 cells by phorbol 12-myristate 13- acetate (PMA), VEGF mRNA expression was up-regulated via a post- transcriptional mRNA stabilization mechanism. PMA treatment exhibited no increase in VEGF-specific transcriptional activation as determined by run- off transcription assays and VEGF promoter-luciferase reporter assays. However, PMA increased VEGF mRNA half-life from 0.8 to 3.6 h which was blocked by PKC inhibitors but not by protein kinase A or cyclic nucleotide- dependent protein kinase inhibitors. When U373 cells were transfected with antisense oligonucleotide sequences to the translation start sites of PKC- α, -β, -γ, -δ, -ε, or -ζ isoforms, both PKC-α and -ζ antisense oligonucleotides showed substantial inhibition of PMA-induced VEGF mRNA. In addition, overexpression of PKC-ζ resulted in a strong constitutive upregulation of VEGF mRNA expression. This study demonstrates for the first time that specific PKC isoforms regulate VEGF mRNA expression through posttranscriptional mechanisms.

Original languageEnglish (US)
Pages (from-to)15407-15414
Number of pages8
JournalJournal of Biological Chemistry
Volume274
Issue number22
DOIs
StatePublished - May 28 1999
Externally publishedYes

Fingerprint

Phorbol Esters
Glioblastoma
Protein Kinase C
Vascular Endothelial Growth Factor A
Protein Isoforms
Messenger RNA
Acetates
Antisense Oligonucleotides
Protein Kinase Inhibitors
Assays
Protein C Inhibitor
Cyclic Nucleotides
Transcription
Cyclic AMP-Dependent Protein Kinases
Luciferases
Runoff
Transcriptional Activation
Half-Life
Tumors
Up-Regulation

ASJC Scopus subject areas

  • Biochemistry

Cite this

Role of protein kinase C isoforms in phorbol ester-induced vascular endothelial growth factor expression in human glioblastoma cells. / Shih, Shu Ching; Mullen, Andrew; Abrams, Kristin; Mukhopadhyay, Debabrata; Claffey, Kevin P.

In: Journal of Biological Chemistry, Vol. 274, No. 22, 28.05.1999, p. 15407-15414.

Research output: Contribution to journalArticle

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