Experimental radioimmunotherapy of HeLa tumours in nude mice with 131I-labeled monoclonal antibodies.
The radioimmunotherapeutic potential of 131I-labeled monoclonal antibodies was investigated in 36 nude mice (BALB/c nu/nu) inoculated s.c. with the HeLa Hep 2 human adenocarcinoma cell line. The membrane bound tumour associated antigen placental alkaline phosphatase and several intracellular cytokeratins served as targets for the antibodies. The specific radioactivity in each organ was determined after i.p. injection of the 131I-labeled antibodies (0.2-0.3 mg, approximately 15 MBq/animal), and high localization to the tumours was seen. Significant growth inhibition was observed after injection of the radiolabeled monoclonal antibody H7 against the placental alkaline phosphatase, which reduced the tumour growth to only 12% during a 3 week period compared to a growth of more than 100% for the controls. Animal weight losses were seen. Synthesis of endogenous antibodies to the target antigens was found to be significant. Morphometric evaluation of the relations between stroma, tumour cells and necrotic areas in the tumours after radioimmunotherapy demonstrated a significant increase of the mean relative connective tissue volume and a significant decreased mean of relative volume of tumour cells in the group treated with iodinated antiplacental alkaline phosphatase antibody. This therapeutic principle is encouraging and may offer new possibilities for future treatment of some malignant diseases.
Riklund
K E
KE
Department of Physiological Chemistry, University of Umeå, Sweden.
Makiya
R A
RA
Sundström
B E
BE
Thornell
L E
LE
Stigbrand
T I
TI
D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism / Q000627:therapeutic use*; D005260:Female; D006367:HeLa Cells; D006801:Humans; D007457:Iodine Radioisotopes / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D002583:Uterine Cervical Neoplasms / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy*
D000911:Antibodies, Monoclonal; D007457:Iodine Radioisotopes