Native MAG-1 antibody almost destroys human breast cancer xenografts.
A native form of mouse monoclonal IgG1 antibody called MAG-1, which recognizes an epitope on provasopressin, has been found to shrink and produce extensive necrosis of human breast tumor xenografts in nu/nu mice. We examined the ability of (90)Yttrium-labeled and native MAG-1 to affect the growth in nu/nu mice of cancer xenografts that were estrogen-responsive (from MCF-7 cells) and triple-negative (from MDA-MB231 cells). The growth rates of treated cells were compared to those receiving saline vehicle and those receiving (90)Yttrium-labeled and native forms of the ubiquitous antibody, MOPC21. Short-term treatments (4 doses over 6 days) not only with (90)Yttrium-MAG-1 but also native MAG-1 produced large reductions in size of rapidly growing tumors of both types, while both (90)Yttrium- MOPC21 and native MOPC21 had no effect. Native and (90)Yttrium-MAG-1 effects were similar, and arrested tumors recommenced growing soon after treatments stopped. Increasing native MAG-1 treatment to single dosing for 16 consecutive days shrank tumors of both types with no regrowth apparent over a 20-day post-treatment period of observation. Pathological examination of such tumors revealed they had undergone very extensive (>66%) necrosis.
North
William G
WG
Departments of Physiology and Pathology, Dartmouth Medical School, Lebanon, NH 03756, USA. william.g.north@dartmouth.edu
Pang
Roy H L
RH
Gao
Guohong
G
Memoli
Vincent A
VA
Cole
Bernard F
BF
D000818:Animals; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000276:immunology* / Q000473:pathology; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D008819:Mice, Nude; D014667:Vasopressins / Q000276:immunology; D023041:Xenograft Model Antitumor Assays; D015019:Yttrium / Q000627:therapeutic use
D000911:Antibodies, Monoclonal; C121421:MOPC21 monoclonal antibody; D014667:Vasopressins; D015019:Yttrium