Combined therapeutic effects of vinblastine and rapamycin on human neuroblastoma growth, apoptosis, and angiogenesis.
OBJECTIVE
Vinblastine and rapamycin displayed synergistic inhibition of human neuroblastoma-related angiogenesis. Here, we studied the antitumor activity of vinblastine and rapamycin against human neuroblastoma.


METHODS
Cell proliferation, cell cycle progression, and apoptosis were evaluated by measuring (3)H-thymidine incorporation, bromodeoxyuridine uptake, and phosphatidylserine exposure, respectively. The in vivo sensitivity of neuroblastoma cells to vinblastine and rapamycin was determined in orthotopic neuroblastoma-engrafted mice. Angiogenesis was assessed by the chick embryo chorioallantoic membrane assay.


RESULTS
Each compound alone was able to induce a dose-dependent significant inhibition of cell proliferation, with a dramatically enhanced antiproliferative effect for the drugs used in combination. A marked G(2)-M cell cycle arrest with a nearly complete depletion of S phase was associated. The combined treatment triggered an increased apoptosis compared with either drug tested alone. A significant inhibition of tumor growth and microvessel area was obtained in neuroblastoma-bearing mice when treated with vinblastine or rapamycin alone, and a more dramatic effect with the combined treatment, compared with control mice. The therapeutic effectiveness, expressed as increased life span, was statistically improved by the combined therapy, compared with mice treated with either drug tested separately. Histologic evaluation of primary tumors showed that the combined treatment inhibited proliferation and angiogenesis and induced apoptosis. Combined treatment of neuroblastoma cells and neuroblastoma-bearing mice with vinblastine and rapamycin induced the down-modulation of both vascular endothelial growth factor production and vascular endothelial growth factor receptor 2 expression. In the chorioallantoic membrane assay, angiogenesis induced by human neuroblastoma biopsy specimens was significantly inhibited by vinblastine and rapamycin.


CONCLUSIONS
These results may be relevant to design new therapeutic strategies against neuroblastoma.
Marimpietri
Danilo
D
Laboratory of Oncology, G.Gaslini Children's Hospital, Italian Neuroblastoma Foundation c/o National Institute for Cancer Research, Genoa, Italy.
Brignole
Chiara
C
Nico
Beatrice
B
Pastorino
Fabio
F
Pezzolo
Annalisa
A
Piccardi
Federica
F
Cilli
Michele
M
Di Paolo
Daniela
D
Pagnan
Gabriella
G
Longo
Luca
L
Perri
Patrizia
P
Ribatti
Domenico
D
Ponzoni
Mirco
M
D020533:Angiogenesis Inhibitors / Q000627:therapeutic use*; D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D017209:Apoptosis; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D006801:Humans; D051379:Mice; D009389:Neovascularization, Pathologic; D009447:Neuroblastoma / Q000188:drug therapy* / Q000378:metabolism; D010718:Phosphatidylserines / Q000737:chemistry; D020123:Sirolimus / Q000008:administration & dosage*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism; D014747:Vinblastine / Q000008:administration & dosage*
D020533:Angiogenesis Inhibitors; D000970:Antineoplastic Agents; D010718:Phosphatidylserines; D014747:Vinblastine; D040301:Vascular Endothelial Growth Factor Receptor-2; D020123:Sirolimus