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D Solter

Publications and source records attributed to D Solter.

At least 91 records · Page 5Linked to original sources

A murine stage-specific embryonic antigen (SSEA-2) is expressed on some murine SV40-transformed cells.

A stage-specific embryonic antigen-2 (SSEA-2) found on murine preimplantation embryos is maximally expressed on 4- to 8-cell stage embryos and is present in decreasing amounts of morulae and blastocysts. This antigenic determinant is also expressed on murine teratocarcinoma cells, sperm, and some, but not all, SV40-transformed mouse cell lines. Analysis of solubilized immunoprecipitates by SDS-gel electrophoresis indicates that this cell surface molecule is not the 54,000 m.w. protein shared by teratocarcinoma and SV40-transformed cell lines.

Absorption

Expression of H-2, laminin and SV40 T and TASA on differentiation of transformed murine teratocarcinoma cells.

Murine embryonal carcinoma cells (ECCs) do not express antigens of the major histocompatibility complex (H-2), but do express cell-surface molecules shared with early embryos. ECCs are also characterized by their insusceptibility to infection by various oncogenic viruses, and their ability to differentiate into a variety of adult cell types. Differentiation of ECCs in vitro can occur spontaneously or can be induced. On exposure to retinoic acid the ECC line F9 (ref. 13) differentiates into cells which have the characteristics of parietal endoderm. When ECCs are exposed to simian virus 40 (SV40), the SV40 tumour (T) antigen is not expressed, although the virus genome reaches the nucleus, and a primary transcript of the SV40 A gene is made. However, following exposure to retinoic acid, the differentiated cells, like most mouse somatic cells, are susceptible to SV40 abortive infection and synthesize large T and small t antigens. To monitor the molecular events associated with the expression of the SV40 A gene on differentiation, we have constructed an ECC line (F9 12-1) containing a single integrated copy of the SV40 genome. This was accomplished by introducing a recombinant plasmid consisting of pBR322 linked to the herpes simplex type 1 thymidine kinase gene and SV40 genome into a thymidine kinase-deficient F9 cell line. We report here that in F9 12-1 cells exposed to retinoic acid, synthesis of the SV40 A gene product(s), T and tumour-associated specific antigens (TASA), parallels the appearance of the normal hallmarks of differentiation in this cell line, H-2 antigens and the basement membrane protein laminin.

Animals

Independent regulation of H-2K and H-2D gene expression in murine teratocarcinoma somatic cell hybrids.

Cells of two teratocarcinoma stem cell lines (PCC4 azaguanine [aza] 1 and F9 5-bromodeoxyuridine [BrdU]) were fused with normal mouse spleen cells and mouse thymoma-derived cells (BW 5147), respectively. Hybrid clones were tested for the expression of molecules coded by the H-2K and -2D genes both by absorption analysis of conventional H-2 sera and by indirect antibody-binding radioimmunoassay with monoclonal antibodies. Somatic cell hybrids between PCC4 aza 1 and spleen cells morphologically resemble teratocarcinoma stem cells and do not express H-2 antigens. However, after differentiation in vitro, one of these hybrid clones expresses the H-2K and -2D gene products of both parental cell lines, one close expresses H-2-D- but not H-2K-coded antigenic determinants, and one clone remains H-2 negative. Somatic cell hybrids between F9 BrdU and BW 5147 resemble fibroblasts. Analysis of a series of hybrid clones revealed some clones that express both the H-2K- and H-2D-coded antigenic specificities of both parental alleles, some that express H-2D gene products strongly and the H-2K gene products very weakly, and some that express H-2D- but not H-2K-coded molecules. These results imply independent regulation of expression of the H-2K and -2D genes. The H-2D gene products appear to be preferentially expressed if the hybrid cells are capable of expressing H-2. The results suggest complex regulatory mechanisms that are H-2K and H-2D specific.

Animals

Embryo-derived teratocarcinoma. II. Teratocarcinogenesis depends on the type of embryonic graft.

Early post-implantation mouse embryos or their embryonic and extraembryonic portions were transplanted under the kidney capsule of adult isogenic recipients in order to test the tumor-producing potential of various grafts and to establish the optimal conditions for teratocarcinoma production. The highest yield of malignant tumors was obtained from 7-day embryos transplanted in toto. Severing the extraembryonic portion of 7-day egg cylinders prior to transplantation of the embryonic part reduced the number of teratocarcinomas to values comparable with those obtained from transplanted 6-day embryos. The extraembryonic portion of 7-day embryos produced no tumors. These data suggest that extraembryonic portions of the 7-day egg cylinder do not have tumorigenic potential alone, but may increase the yield of teratocarcinomas from the embryonic portion of the egg cylinder.

Animals

Localization of I-131-labeled tumor-specific monoclonal antibody in the tumor-bearing BALB/c mouse.

One of the most frequent indications for patient imaging is the need to establish the presence or absence of malignant disease. Considerable effort has been invested in attempting to develop tumor-specific radiopharmaceuticals. We report the localization of an iodine-131-labeled, hybridoma-derived monoclonal antibody in the MH-15 teratocarcinoma-bearing BALB/c mouse. Tumor-to-muscle and tumor-to-blood ratios of 150:1 and 15:1, respectively, were observed at 5 days after administration of 15 microCi of labeled antibody. The relationship between the optimal imaging time and localization kinetics is discussed.

Animals

Cell line derived from a metastasis of a human testicular germ cell tumor.

A cell line, designated 833K-E, has been established from a metastasis of a human testicular germ cell tumor that consisted of four histological types of tumor cells. The 833K-E cells have morphological and ultrastructural characteristics of epithelial cells and a hyperdiploid karyotype indicative of their human male origin. The cells grow in agar cultures and produce in nude mice tumors which have the hstological features of embryonal carcinoma without differentiated elements. Many of the cells express a stage-specific mouse embryonic antigen, and low levels of the major histocompatibility antigens and beta 2-microglobulin also were detected on a large percentage of the cells. A lymphoblastoid cell line (833K-LC) established from the same tumor specimen expresses major histocompatibility antigens and beta 2-microglobulin but does not express the embryonic antigen.

Animals

Embryo-derived teratocarcinoma: I. The role of strain and gender in the control of teratocarcinogenesis.

The role of gender and genetic (strain-specific) factors in the regulation of teratocarcinogenesis was studied by monitoring the outgrowth of benign and malignant embryo-derived teratoid tumors, i.e., teratomas and teratocarconomas in several mouse strains. Teratocarcinomas were produced in all mouse strains tested, but the ratio of teratoma to teratocarcinoma varied from one strain to another. A high yield of teratocarcinomas was obtained in A/J, BALB/cJ, DBA/2J, CBA/J and C3H/J mice, irrespective of the sex of the recipient. A low yield of teratocarcinomas was obtained in both male and female C57BL/6J and AKR/J recipients, and in 129/J female recipients. For all strains but 129/J and eventually AKR/J the sex of the recipients did not significantly affect the outgrowth of embryo-derived tumors. These data suggest the existence of mouse strains with high and low permissiveness for embryo-derived teratocarcinogenesis. The sex of the recipients may influence the yield of embryo-derived teratocarcinomas in some mouse strains but is of no consequence in others.

Animals

Teratomas.

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Animals

Cytoplasmic and nuclear protein synthesis in preimplantation mouse embryos.

Cytoplasmic and nuclear proteins synthesized by mouse embryos at different stages of preimplantation development were analyzed by two-dimensional polyacrylamide gel electrophoresis. Several nuclear-specific proteins (i.e. proteins more abundant in the nucleus than in the cytoplasm) and numerous cytoplasmic-specific proteins were observed. The trends of changes in the nuclear and cytoplasmic protein synthesis are similar. Moderate changes occur between the unfertilized egg and the zygote. Striking changes characterized by the disappearance of numerous major oocyte-specific proteins and the appearance of a large number of new, stage-specific proteins occur between the zygote and the 4- to 8-cell stages. In contrast, between the 4- and 8-cell and early blastocyst periods, only a few new proteins appear, and a small number of oocyte-specific or other stage-specific proteins disappear. Minor differences in protein synthesis were observed between the trophoblast and inner cell mass.

Animals