A tumour spheroid model for antibody-targeted therapy of micrometastases

Abstract

Human neuroblastoma cells grown as tumour spheroids were briefly incubated with a conjugate of131I and an anti-human neuroectodermal monoclonal antibody UJ 1 3A. Unbound131I was removed by washing and the spheroids observed in culture conditions for up to 4 weeks. Spheroid response to irradiation was evaluated as time to reach 10x treatment volume and proportion of spheroids sterilised. Spheroid growth was found to be affected by both the activity of131I-UJ13A and the duration of the incubation. Na[131I],1311-HSA,131I labelled non-specific antibody and unlabelled antibody were found to be relatively ineffective compared to131I-UJ 1 3A. The tumour spheroid model has applications in the evaluation of antibodies or antibody fragments and different radionuclides which may be considered for radioimmunotherapy of micrometastases. © 1988 The Macmillan Press Ltd.