Immunophenotype of human ovarian malignancies (cystadenocarcinomata and mixed müllerian tumor) established in SCID mice.

Human ovarian malignancies from three different patients (histology: two serous cystadenocarcinomata and one mixed Müllerian tumor, homologous type) were successfully serially transplanted intraperitoneally into severe combined immunodeficient (SCID) mice where the tumor cells spread around the peritoneal cavity. If the ascites derived from cystadenocarcinoma cells engrafted in the female genital tract of the SCID mice, they formed cystic tumors resembling remarkably well the original tumors in the patients. Immunohistochemical analysis revealed that the immunophenotype of the patients' original tumor and those grown in SCID mice were similar in the case of the two cystadenocarcinomata; in addition, the marker expression in general was stable during serial transplantation. If distant metastases occurred in the lungs, they immunophenotypically resembled those grown intraperitoneally. In contrast, the cells derived from the mixed Müllerian tumor shifted during serial transplantation from a spindle cell morphology toward a morphology characterized by cuboidal cells. The transition toward a more epithelial phenotype was accompanied by a changed immunophenotype of the tumor cells which became positive for epithelial cell markers such as carcinoembryonic antigens, CA 19-9 and CA 125. Concurrently with this differentiation, the p53 immunophenotype changed from positive to negative, indicating a further mutation in the p53 gene during serial passages.