Response of a human colon adenocarcinoma (DLD-1) to X irradiation and mitomycin C in vivo.
Mice hosting a heterogeneous human colon xenograft tumor produced by subcutaneous injection of the DLD-1 tumor cell line were treated either with x irradiation alone, with mitomycin C alone (4 mg/kg), or with x irradiation given two hours after intraperitoneal injection of mitomycin C (4 mg/kg). Radiation alone produced a dose dependent delay in the time needed for tumors to regrow to twice their size at the time of irradiation, and in the mice receiving mitomycin C plus x irradiation, an additional growth delay equivalent to that produced by 3-3.5 Gy of X rays was seen at all X ray dose levels. As the DLD-1 tumor xenografts do not appear to possess a significant hypoxic fraction, we conclude that the two agents are acting in a simple additive cytotoxic manner by the killing of oxic tumor cells.
D000230:Adenocarcinoma / Q000188:drug therapy / Q000532:radiotherapy / Q000628:therapy*; D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000008:administration & dosage*; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000532:radiotherapy / Q000628:therapy*; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D016685:Mitomycin; D008937:Mitomycins / Q000008:administration & dosage*; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000188:drug therapy / Q000532:radiotherapy; D014183:Transplantation, Heterologous
D000903:Antibiotics, Antineoplastic; D008937:Mitomycins; D016685:Mitomycin