TY - JOUR
T1 - Maximum tolerable dose and low-dose metronomic chemotherapy have opposite effects on the mobilization and viability of circulating endothelial progenitor cells
AU - Bertolini, Francesco
AU - Paul, Saki
AU - Mancuso, Patrizia
AU - Monestiroli, Silvia
AU - Gobbi, Alberto
AU - Shaked, Yuval
AU - Kerbel, Robert S.
PY - 2003/8/1
Y1 - 2003/8/1
N2 - There is growing evidence that vasculogenesis (progenitor cell-derived generation of new blood vessels) is required for the growth of some neoplastic diseases. Here we show that the administration of cyclophosphamide (CTX) at the maximum tolerable dose with 21-day breaks or at more frequent low-dose (metronomic) schedules have opposite effects on the mobilization and viability of circulating endothelial progenitors (CEPs) in immunodeficient mice bearing human lymphoma cells. Animals treated with the maximum tolerable dose CTX experienced a robust CEP mobilization a few days after the end of a cycle of drug administration, and tumors rapidly became drug resistant. Conversely, the administration of metronomic CTX was associated with a consistent decrease in CEP numbers and viability and with more durable inhibition of tumor growth. Our findings suggest that metronomic low-dose chemotherapy regimens are particularly promising for avoiding CEP mobilization and, hence, to potentially reduce vasculogenesis-dependent mechanisms of tumor growth.
AB - There is growing evidence that vasculogenesis (progenitor cell-derived generation of new blood vessels) is required for the growth of some neoplastic diseases. Here we show that the administration of cyclophosphamide (CTX) at the maximum tolerable dose with 21-day breaks or at more frequent low-dose (metronomic) schedules have opposite effects on the mobilization and viability of circulating endothelial progenitors (CEPs) in immunodeficient mice bearing human lymphoma cells. Animals treated with the maximum tolerable dose CTX experienced a robust CEP mobilization a few days after the end of a cycle of drug administration, and tumors rapidly became drug resistant. Conversely, the administration of metronomic CTX was associated with a consistent decrease in CEP numbers and viability and with more durable inhibition of tumor growth. Our findings suggest that metronomic low-dose chemotherapy regimens are particularly promising for avoiding CEP mobilization and, hence, to potentially reduce vasculogenesis-dependent mechanisms of tumor growth.
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M3 - Article
C2 - 12907602
AN - SCOPUS:0041589524
VL - 63
SP - 4342
EP - 4346
JO - Journal of Cancer Research
JF - Journal of Cancer Research
SN - 0008-5472
IS - 15
ER -