A human pancreatic tumor cell line has been established from the ascites of a patient with histopathologically confirmed adenocarcinoma of the head of the pancreas and maintained for more than 12 months in the laboratory. Epithelioid tumor cell colonies, which resulted from primary tissue cultures of the ascitic cell component, were mechanically isolated by needle micromanipulation. Tumorigenicity was proven in athymic nude mice. Morphologically the pancreatic tumor epithelial cells grew to confluency with moderately tight adhesion to the culture plastic surface and with free-floating cells in the medium. Upon re-establishment of the tumoral xenograft in tissue culture, the epithelial cells retained their original morphology. Histologically the tumor grown in nude mice exhibited prototypic characteristics of the primary adenocarcinoma in the patient, producing abundant mucin and displaying a broad spectrum of glandular differentiation, which ranged from well to poorly differentiated adenocarcinomas with occasionally localized lymphocytic infiltrations. Furthermore, the tumor expressed carcinoembryonic antigen and human pancreas cancer associated antigen. This tumor line, designated AsPC-1, has been cultured for at least 10 passages in vitro and 3 in vivo. It represents a new model for human pancreatic cancer.

A phase 1 study was conducted with the investigational immunoscintigraphic agent, 111In-CYT-356, a radiolabeled, site-specific immunoconjugate of monoclonal antibody 7E11-C5.3, in 40 patients with prostatic carcinoma and known distant metastases. Each patient received a single intravenous infusion of CYT-356 (dose range, 0.1-5 mg) radiolabeled with approximately 5 mCi of 111In. None of the patients experienced adverse reactions. One patient who received a 5-mg dose developed antibodies to the CYT-356 immunoconjugate. 111In-CYT-356 immunoscintigraphy detected bony metastases in 21 of 38 patients (55%), including 12 of 14 (86%) receiving concomitant hormonal therapy, and soft tissue lesions in four of six patients (67%). Antibody imaging detected occult lesions in the bony pelvis and lumbar spine, which were confirmed by follow-up imaging tests, in one patient. Higher CYT-356 doses may clear the blood pool more slowly. These results suggest that 111In-CYT-356 can be safely administered to patients with prostatic carcinoma and that further clinical investigation of this agent is warranted.

Infection of mice with the polycythemia-inducing strain of Friend leukemia virus caused a rapid emergence of new erythroid precursor cells. These cells which, in the absence of erythropoietin, proliferated in vitro to form colonies and even differnetiated, quickly out-numbered the usual erythropoietin-dependent hematopoietic elements in bone marrow and spleen. Ultimately, the marrow and spleen were probably totally repopulated with this erythropoietin-independent cell.

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