Deregulated Bcl-2 gene expression selectively prolongs survival of growth factor-deprived hemopoietic cell lines

J Immunol. 1990 May 1;144(9):3602-10.

Abstract

The t(14;18) of human follicular B cell lymphoma translocates the Bcl-2 gene into the Ig H chain locus and markedly deregulates Bcl-2 expression. We sought to determine if Bcl-2 could be directly implicated in a growth-factor pathway. Consequently, we introduced a retrovirus containing the murine Bcl-2 gene (N2-M-Bcl-2) or the parental retrovirus (N2) into a series of factor-dependent hemopoietic cell lines. Overexpressed Bcl-2 resulted in no long term IL-2, IL-3, or IL-6 independent clones, indicating that Bcl-2 could not spare the need for a specific ligand-receptor interaction. However, Bcl-2 did extend the short term survival of IL-3-dependent cell lines after factor deprivation. Although viable, IL-3-deprived pro B lymphocytes (FL5.12) bearing N2-M-Bcl-2 were in Go, and deregulated Bcl-2 did not obviously influence cell-cycle progression. Bcl-2 predominant effects were to delay the onset of cell death and to modestly augment viable cell growth in the first 48 h after IL-3 deprivation. This death sparing was associated with increased levels of Bcl-2 RNA and protein in factor-deprived cells possessing N2-M-Bcl-2. This result was not restricted to prolymphocytes because an IL-3-dependent mast cell line (32D) as well as a promyeloid line (FDC-P1) demonstrated the same response to Bcl-2. Moreover, the effect was not limited to the IL-3/IL-3R signal transduction pathway in that promyeloid cells maintained in granulocyte-macrophage-CSF or IL-4 displayed a similar response. Yet, Bcl-2-enhanced cell survival was not universal as an IL-2-dependent T cell line, and an IL-6-dependent myeloma line demonstrated no consistent effect upon IL withdrawal. Thus, Bcl-2 appears to interfere with cell death but in a cell type and/or factor-restricted fashion.

MeSH terms

  • Animals
  • Blotting, Northern
  • Blotting, Southern
  • Cell Line
  • Cell Survival*
  • Cloning, Molecular
  • Flow Cytometry
  • Gene Expression
  • Genetic Vectors
  • Growth Substances / pharmacology
  • Hematopoietic Stem Cells / cytology*
  • Hematopoietic Stem Cells / physiology
  • Interleukin-2 / physiology
  • Interleukin-3 / physiology
  • Interleukin-6 / physiology
  • Mice
  • Monosaccharide Transport Proteins / genetics
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins / physiology*
  • Proto-Oncogene Proteins c-bcl-2
  • Proto-Oncogene Proteins c-myc
  • RNA, Messenger / genetics

Substances

  • Growth Substances
  • Interleukin-2
  • Interleukin-3
  • Interleukin-6
  • Monosaccharide Transport Proteins
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • Proto-Oncogene Proteins c-myc
  • RNA, Messenger