Human Carcinoma Cell Lines Xenografted in Athymic Mice: Biological and Antigenic Characterization of an Intra-Abdominal Model

Abstract

In the perspective of in vivo clinical application of monoclonal antibodies (MoAbs) directed against human ovarian carcinoma a preclinical in vivo model was developed using athymic mice. Three human carcinoma cell lines (MCF7, HT29 and SW626) were injected into the peritoneal cavity of pristane primed animals and the biologic and antigenic characteristics of the i.p. grown tumors were studied. Tumor take was observed in 85% of the injected animals and palpable nodules became apparent in 83% of the cases 14-27 days after injection. Examination at autopsy of the peritoneal cavity revealed tumor masses varying in size from 0.2 to 0.5 cm in diameter and tumor sheets implanted in the diaphragm. The liver, bowel mesentery and pancreas were also invaded. Ascitic fluid formation was rare and no animal developed vivo tumors outside the peritoneal cavity. To determine whether the in vivo tumors retained the same antigenic characteristics as the in vitro cell lines, 4 MoAbs directed against ovarian carcinoma associated antigens and 2 different ex perimental approaches (immunofluorescence and immunoblotting) were used.