Low-dose cyclophosphamide inhibition of transplantable fibrosarcoma growth by augmentation of the host immune response.
Preinjection of a low dose of cyclophosphamide (Cy) (500 microgram/mouse) either delayed or inhibited tumor appearance following the inoculation of transplantable 3-methylcholanthrene-induced fibrosarcomas in inbred male C3H/HeJ mice. This dose of Cy decreased the spleen weight by 13% and the total spleen cell count by 23%. However, the same dose could potentiate the footpad swelling reaction (FPSR) measured against Staphylococcus aureus antigen. Splenic lymphocytes from Cy-treated animals showed increased blastogenic response against phytohemagglutinin-M and bacterial lipopolysaccharide. Thus 500 micrograms Cy/animal may have depleted suppressor cell populations leading to: a) an increase in FPSR, b) increased blastogenic transformation of lymphocytes, and c) tumor growth inhibition.
D000818:Animals; D002460:Cell Line; D003520:Cyclophosphamide / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D005354:Fibrosarcoma / Q000188:drug therapy / Q000276:immunology*; D007111:Immunity, Cellular / Q000187:drug effects; D008213:Lymphocyte Activation / Q000187:drug effects; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D009368:Neoplasm Transplantation; D013154:Spleen / Q000166:cytology
D003520:Cyclophosphamide