Nitric oxide-mediated apoptosis of K-1735 melanoma cells is associated with downregulation of Bcl-2

Oncogene. 1997 Aug 14;15(7):771-9. doi: 10.1038/sj.onc.1201239.


Recent studies have shown that the treatment of nonmetastatic K-1735 murine melanoma cells with cytokines induces the production of nitric oxide (NO) and hence cell death. The purpose of this study was to determine the mechanism of this cytokine-induced NO-mediated apoptosis. Incubation of nonmetastatic K-1735 cells with interleukin-1 alpha (IL-1alpha) and interferon-gamma (IFN-gamma) induced high NO production, Bcl-2 downregulation, and apoptotic cell death. In contrast, incubation of metastatic K-1735 cells with IL-1alpha and IFN-gamma did not induce significant production of NO, downregulation of Bcl-2, or cell death. The exposure to exogenous NO derived from the NO donors, sodium nitroprusside (SNP), or GEA5024 produced a dose-dependent apoptotic cell death in both the metastatic and nonmetastatic K-1735 cells, which was associated with downregulation of Bcl-2 at the mRNA level and, to a lesser extent, at the protein level. Nonmetastatic and metastatic K-1735 cells transfected with the Bcl-2 gene were more resistant to apoptosis mediated by both endogenous and exogenous NO. Subsequent to intravenous injection, the tumor cells transfected with the Bcl-2 gene had an increased survival rate in the lungs of nude mice and produced a higher number of experimental lung metastases. These data suggest that NO-induced apoptosis in K-1735 melanoma cells is associated with downregulation of Bcl-2.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Apoptosis / genetics
  • Apoptosis / physiology*
  • DNA Fragmentation
  • Down-Regulation
  • Genetic Vectors
  • Interferon-gamma / pharmacology
  • Interleukin-1 / pharmacology
  • Lung Neoplasms / secondary
  • Melanoma / genetics
  • Melanoma / metabolism*
  • Melanoma / pathology*
  • Melanoma / secondary
  • Mice
  • Mice, Inbred C3H
  • Mice, Nude
  • Nitric Oxide / antagonists & inhibitors
  • Nitric Oxide / physiology*
  • Proto-Oncogene Proteins c-bcl-2 / drug effects
  • Proto-Oncogene Proteins c-bcl-2 / genetics
  • Proto-Oncogene Proteins c-bcl-2 / metabolism*
  • Transfection
  • Triazoles / metabolism
  • Triazoles / pharmacology
  • Tumor Cells, Cultured


  • Interleukin-1
  • Proto-Oncogene Proteins c-bcl-2
  • Triazoles
  • GEA 5024
  • Nitric Oxide
  • Interferon-gamma