Immunoscintigraphy of MCF7 rat mammary tumour xenograft using monoclonal antibody

A transplantable, ER+ mammary carcinoma has been induced in virgin female Wistar rats by an 'air-pouch' technique by xenografting MCF7 cells. An air pouch induced by injecting sterile air subcutaneously into the mammary fat pad was primed with pristane and 17 beta estradiol (10 micrograms) in peanut oil prior to injection of 2-5 x 10(7) MCF7 cells fresh from culture. Solid tumours developed within 1-3 months (0.5-3.4 cm diam.) well encapsulated, pediculated tumours with histology of adenocarcinoma (> 80%) and fibroadenoma (< 10%), the former tumour being estrogen-dependent and transplantable. Monoclonal antibody 15C3 generated against MCF7 cells in this laboratory has been used for Tc-99m immunoscintigraphic studies by "SPECT" analysis of this mammary carcinoma and revealed selective localization of Tc-99m resulting in highly distinct tumour images.