Treatment of melanoma cells with a bcl-2/bcl-xL antisense oligonucleotide induces antiangiogenic activity.
We have recently reported that bcl-2 overexpression and hypoxia synergistically interact to modulate vascular endothelial growth factor (VEGF) and in vivo angiogenesis in tumour cells through VEGF mRNA stabilization and hypoxia-inducible factor 1-mediated transcriptional activity. Bcl-2 antisense treatment has shown promising clinical results in patients with malignant melanoma. In the present study, we demonstrated that the bcl-2/bcl-xL bispecific antisense oligonucleotide 4625 inhibits bcl-2 expression and angiogenesis in two bcl-2 overexpressing clones derived from the M14 human melanoma cell line. The antiangiogenic effect was determined in in vitro and in vivo angiogenesis assays. In particular, a reduction of hypoxia-induced VEGF secretion was observed after 4625 treatment, and the conditioned medium (CM) of bcl-2 overexpressing clones treated with 4625 and exposed to hypoxic conditions resulted in decreased endothelial cell proliferation when compared to CM of untreated control cells. In addition, we found that CM of 4625 antisense-treated bcl-2 transfectants inhibited in vivo vessel formation in matrigel plugs implanted subcutaneously in C57/B16 mice. Our findings confirm that bcl-2 plays a crucial role in melanoma angiogenesis and demonstrate for the first time that downregulation of bcl-2 by antisense treatment has potential to inhibit angiogenesis independent of its effect on cell survival. The use of 4625 in cancer therapy is suggested as an approach to facilitate simultaneously tumour cell apoptosis and inhibit tumour angiogenesis.
Del Bufalo
Donatella
D
Experimental Chemotherapy Laboratory, Regina Elena Cancer Institute, Via delle Messi d'Oro 156, 00158 Rome, Italy.
Trisciuoglio
Daniela
D
Scarsella
Marco
M
Zangemeister-Wittke
Uwe
U
Zupi
Gabriella
G
D020533:Angiogenesis Inhibitors / Q000494:pharmacology*; D000818:Animals; D006801:Humans; D008545:Melanoma / Q000188:drug therapy*; D051379:Mice; D008810:Mice, Inbred C57BL; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics*; D042461:Vascular Endothelial Growth Factor A / Q000187:drug effects; D051020:bcl-X Protein
D020533:Angiogenesis Inhibitors; C494811:BCL2L1 protein, human; C494812:Bcl2l1 protein, mouse; D016376:Oligonucleotides, Antisense; D019253:Proto-Oncogene Proteins c-bcl-2; D042461:Vascular Endothelial Growth Factor A; D051020:bcl-X Protein