Nitric oxide-mediated apoptosis of K-1735 melanoma cells is associated with downregulation of Bcl-2.
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.
Xie
K
K
Department of Cell Biology, The University of Texas M.D. Anderson Cancer Center, Houston 77030, USA.
Wang
Y
Y
Huang
S
S
Xu
L
L
Bielenberg
D
D
Salas
T
T
McConkey
D J
DJ
Jiang
W
W
Fidler
I J
IJ
D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D053938:DNA Fragmentation; D015536:Down-Regulation; D005822:Genetic Vectors; D007371:Interferon-gamma / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology; D008175:Lung Neoplasms / Q000556:secondary; D008545:Melanoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology* / Q000556:secondary; D051379:Mice; D008809:Mice, Inbred C3H; D008819:Mice, Nude; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000502:physiology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D014230:Triazoles / Q000378:metabolism / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D007375:Interleukin-1; D019253:Proto-Oncogene Proteins c-bcl-2; D014230:Triazoles; C082873:GEA 5024; D009569:Nitric Oxide; D007371:Interferon-gamma