Substances that can trigger activation of the alternative pathway of complement have anti-melanoma activity in mice.
Intraperitoneal (i.p.) injection of substances that can ignite the alternative pathway of complement, namely isolated human C3b or C3(H2O), guinea-pig C3(H2O) or cobra venom factor, or conventionally prepared zymosan, will reproducibly and very significantly increase the mean survival time of C57BL mice previously inoculated i.p. with melanoma cells. The effect is greater at higher doses and earlier post-inoculation (p.i.) administration, but the substances are active at low doses (30-100 micrograms/mouse) if given early enough. It is likely that C3b or C3(H2O) was the previously unidentified anti-tumour factor activated in serum by S. aureus treatment or serum fractionation and described elsewhere. Activation of the alternative pathway of complement appears to have potential interest for cancer therapy.
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D003167:Complement Activation / Q000187:drug effects*; D003176:Complement C3 / Q000494:pharmacology; D003179:Complement C3b / Q000494:pharmacology; D003170:Complement Pathway, Alternative / Q000187:drug effects*; D004546:Elapid Venoms / Q000494:pharmacology; D006168:Guinea Pigs; D006801:Humans; D008545:Melanoma / Q000188:drug therapy*; D051379:Mice; D015054:Zymosan / Q000494:pharmacology
D000970:Antineoplastic Agents; D003176:Complement C3; D004546:Elapid Venoms; C016310:cobra venom factor; D003179:Complement C3b; D015054:Zymosan