[Synergistic antitumor activity of human breast cancer immunotoxins].
Three anti-breast carcinoma monoclonal antibodies 317G5, 260F9 and 741F8 linked to ricin A chain (rRTA) were selected for the present investigation. Attempts were made to understand the relative efficiency of these immunotoxins in relation to: a) binding, b) internalization, and c) clonogenic suppression of breast cancer cells in vitro. The results indicated that 317G5-rRTA combined with 260F9-rRTA had synergistic antitumor activity against SKBr3 breast carcinoma cell line. Individually, 10 micrograms/ml 260F9-rRTA or 317 G5-rRTA alone could only eliminate 2-3 logs of clonogenic SKBr3 cells. When used in combination, 260F9-rRTA and 317G5-rRTA, 1 microgram/ml each, could kill 4 logs of clonogenic tumor cells. The mechanism of the synergistic action is discussed.
Yu
Y H
YH
Peking Union Medical College Hospital, Beijing.
D000911:Antibodies, Monoclonal / Q000494:pharmacology; D000912:Antibodies, Neoplasm / Q000494:pharmacology; D001943:Breast Neoplasms / Q000473:pathology*; D002999:Clone Cells; D004357:Drug Synergism; D006801:Humans; D000922:Immunotoxins / Q000494:pharmacology*; D012276:Ricin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D000912:Antibodies, Neoplasm; D000922:Immunotoxins; D012276:Ricin