Transcription factor TFII-I causes transcriptional upregulation of GRP78 synthesis in prostate cancer cells

J Cell Biochem. 2009 Feb 15;106(3):381-9. doi: 10.1002/jcb.22016.

Abstract

Receptor-recognized forms of alpha(2)-macroglobulin (alpha(2)M*) bind to cell surface-associated GRP78 and induce proliferative and survival signaling in prostate cancer cells. As part of the cellular response to alpha(2)M*, GRP78 expression is itself upregulated. In response to other stimuli, the transcription factor TFII-I upregulates GRP78 by binding to its gene promoter. We have, therefore, studied the role of TFII-I in transcriptional upregulation of GRP78 in 1-LN human prostate cancer cells stimulated with alpha(2)M*. This treatment caused a two- to threefold increase in TFII-I and GRP78 synthesis from [(35)S]-labeled precursor amino acids. Synthesis of both TFII-I and GRP78 were significantly reduced by silencing TFII-I gene expression or pretreatment of cells with genistein or actinomycin D. Confocal microscopy was employed to demonstrate relocation of TFII-I to the nucleus. In alpha(2)M*-stimulated cells, moreover, TFII-I bound to the GRP78 promoter as determined by CHIP assay. We also demonstrate binding of TFII-I to the c-fos promoter, consistent with its role in upregulating c-fos gene expression. In non-lymphoid cells, phosphorylated c-Src is an activator of TFII-I. Ligation of GRP78 on 1-LN cells with alpha(2)M* was followed by tyrosine phosphorylation of c-Src as well as TFII-I. We conclude that alpha(2)M*-induced increase in GRP78 synthesis is caused by transcriptional upregulation of TFII-I which binds to the GRP78 promoter and thus potentiates its cell survival and antipoptotic functions in 1-LN prostate cancer cells.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • CSK Tyrosine-Protein Kinase
  • Cell Line, Tumor
  • Endoplasmic Reticulum Chaperone BiP
  • Gene Expression Regulation, Neoplastic / drug effects
  • Gene Expression Regulation, Neoplastic / genetics*
  • Heat-Shock Proteins / biosynthesis
  • Heat-Shock Proteins / genetics*
  • Humans
  • Male
  • Molecular Chaperones / biosynthesis
  • Molecular Chaperones / genetics*
  • Phosphorylation
  • Phosphotyrosine / metabolism
  • Prostatic Neoplasms / genetics*
  • Prostatic Neoplasms / metabolism
  • Prostatic Neoplasms / pathology*
  • Protein Binding
  • Protein Transport
  • Protein-Tyrosine Kinases / metabolism
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins c-fos / metabolism
  • RNA Interference
  • Transcription Factors, TFII / genetics
  • Transcription Factors, TFII / metabolism*
  • Transcription, Genetic / drug effects
  • Transcription, Genetic / genetics*
  • Up-Regulation / drug effects
  • Up-Regulation / genetics*
  • alpha-Macroglobulins / pharmacology
  • src-Family Kinases

Substances

  • Endoplasmic Reticulum Chaperone BiP
  • GTF2I protein, human
  • HSPA5 protein, human
  • Heat-Shock Proteins
  • Molecular Chaperones
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-fos
  • Transcription Factors, TFII
  • alpha-Macroglobulins
  • Phosphotyrosine
  • Protein-Tyrosine Kinases
  • CSK Tyrosine-Protein Kinase
  • src-Family Kinases
  • CSK protein, human