Radioimmunoscintigraphy of human malignant melanoma. I. Pharmacokinetics and localization of 125I-labeled monoclonal antibody RG-12 in thymectomized mice bearing renal melanoma xenotransplants.

The novel RG-12 monoclonal antibody (MoAb) recognizing a high-molecular-weight antigen of human melanoma cells was radioiodinated and its biodistribution and tumor imaging was determined in immunosuppressed mice bearing xenografted human malignant melanoma HMB-2. Control and tumor-bearing mice were injected with 6 micrograms of 125I-labeled RG-12 IgG (8.9 MBq 125I-IgG/animal).

Biological and immunological properties of the HMB-2 human melanoma cell line.

The HMB-2 human melanoma cell line derived from a lymph node metastatis is described. After long-term cultivation in vitro the cells retained their morphology, high growth rate, xenotransplantability into immunosuppressed mice and genotypic and phenotypic markers of human melanoma cells. Upon infection of the HMB-2 cells with temperature-sensitive mutant vesicular stomatitis virus (VSVts045) at nonpermissive temperature, a complemented virus pseudotype (VSV(HMB-2] was produced carrying assembled melanoma-associated antigens.

[Expression of virus-specific functions in 3-methylcholanthrene-induced leukemia in rats].

It was isolated and identified MR-Le virus from Wistar rats with myelogenous leukemia. The comparison of isolated in vivo and in vitro MR-Le virus with endogenous oncovirus RaLV in protein profile as well as results of molecular hybridization pointed out that RaLV did not participate in the induction of MR leukemia. The question about the role of MR-Le virus in the etiology of MR leukemia is opened now.

Expression of retrovirus-related functions in the methylcholanthrene-induced rat myelogenous leukemia.

The rat MR-leukemia (MR-Le) induced in Wistar rats by methylcholanthrene and whole-body irradiation, has been shown to be transmitted by means of cell-free filtrates of spleen and liver extracts. These earlier results lead us to determine the expression of retroviral functions by MR-Le myeloblasts in vivo and in vitro. DNA polymerase activity associated with particulate material purified from plasma of rats carrying MR-Le and from MR-Le tissue culture fluid, increased with the number of MR-Le myeloblasts.

Organization of proviral DNA and protein composition of hormonally stimulated C57Bl/10 strain-associated mouse mammary tumor virus.

Two continuous lines, BL-MaTU/A1 and BL-MaTU/s6, were established from C57Bl/10 mammary adenocarcinomas induced by DMBA-prolactin-estradiol treatment. Under in vivo stimulation with dexamethasone, insulin, prolactin, and prostaglandin A1, the cells produce detectable amounts of B-type particles with biochemical properties similar to the GR-MuMTV. Analysis of restriction endonuclease-generated fragments of cellular DNA revealed identical patterns in the integration sites and internal recognition sites of MuMTV proviral equivalents in the tumor cells and normal organs of C57Bl/10 strain mice.