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C M Croce

Publications and source records attributed to C M Croce.

At least 451 records · Page 25Linked to original sources
PubMed1978

Chimeric mice derived from human-mouse hybrid cells.

Mouse teratocarcinoma cells from the OTT6050 ascites tumor were established in tissue culture and selected for 5-bromodeoxyuridine (BrdUrd) resistance. The embryonal carcinoma cells grew without a feeder layer, remained deficient for thymidine kinase (EC 2.7.1.75), and differentiated like the original tumor into various tissues after subcutaneous injection into 129 mice. We fused the BrdUrd-resistant mouse teratocarcinoma cells with HT1080-6TG human diploid fibrosarcoma cells deficient in hypoxanthine phosphoribosyltransferase (EC 2.4.2.8) and selected for hybrid cells in hypoxanthine/aminopterin/thymidine medium. The resulting hybrid cells segregated human chromosomes quickly and retained one to three human chromosomes including chromosome 17 that carries the human genes for thymidine kinase and galactokinase (EC 2.7.1.6). Single hybrid cells from five independent clones containing human chromosome 17 were injected into mouse blastocysts bearing several genetic markers that affect the coat color phenotype and strain-specific enzyme variants in order to detect tissue differentiation derived from the injected cells. After the injection of single hybrid cells into a total of 103 experimental blastocysts that had been surgically transferred to pseudopregnant foster mothers, 49 mice were born and 2 of them clearly revealed coat mosaicism. In 2 of 17 mice thus far analyzed, the injected hybrid cells proved to be capable of participating substantially in development of seven different organs. However, human gene products have not yet been detected unequivocally in those tissues and weak human-specific galactokinase activity could be recovered only from two mosaic tissues. Our results demonstrate that, after in vitro culture and selection, at least some of the human-mouse hybrid cells still retain their in vivo potential to differentiate and become functionally integrated in the living organism. It now seems feasible to cycle mouse teratocarcinoma cells carrying human genetic material through mice via blastocyst injection to study human gene expression during differentiation.

Animals↗
PubMed1978

Somatic cell hybrids producing antibodies specific for the tumor antigen of simian virus 40.

We have produced somatic cell hybrids between mouse myeloma cells deficient in hypoxanthine phosphoribosyltransferase IMP: pyrophosphate phosphoribosyltransferase; EC 2.4.2.8) and spleen cells derived from mice primed with either syngeneic or allogeneic cells transformed by simian virus 40. Such hybrids produced antibodies specific for simian virus 40 tumor (T) antigen. Only four of twelve independent hybrid cell cultures produced antibodies against simian virus 40 T antigen that crossreacted with the T antigen induced by BK virus, a human papovavirus isolated from patients who had undergone immunosuppressive therapy.

Animals↗
PubMed1978

Chromosomal locations of mouse immunoglobulin genes.

The chromosomal locations of the structural genes coding for the constant portions of mouse heavy (H) and light chain immunoglobulins were studied by molecular hybridization techniques. Complementary DNA probes containing the constant-region sequences of kappa and lambdaI light chain and alpha, gamma2b, and mu heavy chain mRNAs were annealed to a large excess of DNA from a series of eight mouse-human hybrid cell lines that are deficient for various mouse chromosomes. The lines were scored as positive when a high proportion of a probe annealed and negative when an insignificant proportion annealed. Some lines were clearly negative for H and lambda and clearly positive for kappa. Others were positive or intermediate for lambda, positive for kappa and negative for H. Still others, including a line that was selected for the absence of the mouse X chromosome, were positive for all immunoglobulin species. These results demonstrate that the Clambda, Ckappa, and CH genes are located on different autosomes in the mouse. In contrast, the three heavy-chain families exhibited consistently uniform hybridization results, suggesting that the genes for Calpha, Cgamma, and Cmu are located on the same chromosome. A comparison of karyotypic data with hybridization data has limited the possible locations of the Ig genes to only a few chromosomes.

Animals↗
PubMed1978

Human tumor and rodent-human hybrid cells with an increased number of active human NORs.

A human fibrosarcoma line, HT1080-6TG, with a near diploid number of chromosomes, has an average of 7.3 chromosomes with an Ag-stained nucleolus organizer region (NOR). Cells of this line with an increased number of chromosomes have an increased number of Ag-stained NORs. This cell line has been used as the human parent in constructing mouse-human and rat-human hybrids that segregate rodent chromosomes. The hybrid ccell lines, which have 100 or more chromosomes per cell, show a proportionate increase in the number of Ag-stained NORs (means, 11.4--16.8). The frequency of association of acrocentric chromosomes increases in a similar fashion. There is no evidence of inactivation of human NORs in these cells.

Animals↗
PubMed1978

Assignment of the gene for lactic dehydrogenase A to mouse chromosome 7 using mouse-human hybrids.

We have studied somatic cell hybrids between either mouse peritoneal macrophages or spleen cells and HT-1080-6TG human fibrosarcoma cells for the expression of mouse lactic dehydrogenase A (LDH-A). The hybrids were also studied for the expression of mouse glucose phosphate isomerase (GPI-1), the gene for which has been assigned to chromosome 7. Concordant segregation of the expression of mouse GPI-1 and LDH-1 was observed in 61 independent hybrid clones. These results indicate that the gene coding for LDH-A is located on mouse chromosome 7.

Animals↗
PubMed1977

Assignment of the structural genes for the alpha subunit of hexosaminidase A, mannosephosphate isomerase, and pyruvate kinase to the region q22-qter of human chromosome 15.

Concordant segregation of the expression of the alpha subunit of human hexosaminidase A, human mannosephosphate isomerase, and pyruvate kinase was observed in somatic cell hybrids between either thymidine kinase-deficient mouse cells or thymidine kinase-deficient Chinese hamster cells and human white blood cells carrying a translocation of the distal half (q 22-qter) of the long arm of chromosome 15 to chromosome 17. A positive correlation was established between the expression of these human phenotypes and the presence of the distal half of the long arm of human chromosome 15.

Carbohydrate Epimerases↗
PubMed1977

Suppression of replication of SV40 and polyoma virus in mouse-human hybrids.

Mouse-human heterokaryons are permissive for the replication of both SV40 virus and polyoma virus. If the hybrids which develop from these heterokaryons segregate human chromosomes (mouse greater than human hybrids), the hybrids are permissive for replication of polyoma virus but not for replication of SV40 virus. If the subsequent hybrids segregate mouse chromosomes (human greater than mouse hybrids), such hybrids support the replication of SV40 virus but not the replication of polyoma virus, even when the hybrids contain at least one copy of each mouse chromosome. This indicates that during the transition from heterokaryon to hybrid cell, suppression of expression of species-specific function(s) required for the replication of these species-specific viruses occurs in parallel with the direction of chromosome loss and suppression of nucleolus organizer activity.

Animals↗
PubMed1977

Assignment of the integration site for simian virus 40 to chromosome 17 in GM54VA, a human cell line transformed by simian virus 40.

GM54VA human cells transformed by simian virus 40 (SV40) were fused with peritoneal macrophages obtained from three different mouse strains. All 27 hybrid clones studied were positive for SV40 tumor antigen in 100% of their cells and contained human chromosome 17. Human chromosome 17 was the only human chromosome present in five of the hybrid clones. Fusion of GM54VA cells and either thymidine kinase (EC 2.7.1.75)-deficient mouse or Chinese hamster fibroblasts resulted in the growth in hypoxanthine-aminopterin-thymidine medium of hybrid clones positive and negative for SV40 tumor antigen. Counterselection of the hybrid clones positive for tumor antigen in medium containing 5-bromodeoxyuridine resulted in the growth of hybrid cells that were negative for tumor antigen. These experiments indicate that negative for tumor antigen. These experiments indicate that SV40 is integrated in only one of the two parental human chromosomes 17. Because the genome of SV40 has been assigned to human chromosome 7 in two other SV40-transformed human cell lines, at least two different integration sites for SV40 would seem to be present in human cells: one located in human chromosome 7 and the other located in human chromosome 17.

Alleles↗
PubMed1977

Suppression of production of mouse 28S ribosomal RNA in mouse-human hybrids segregating mouse chromosomes.

Mouse-human somatic cell hybrids that lose (segregate) human chromosomes produce only mouse 28S ribosomal RNA even when they retain copies of the human chromosomes that contain the genes for 28S ribosomal RNA. In contrast, mouse-human hybrid cells that segregate mouse chromosomes produce only human 28S ribosomal RNA even when they have retained copies of mouse chromosomes that contain the 28S ribosomal RNA genes.

Animals↗
PubMed1977

Tumorigenicity of simian virus 40-transformed human cells and mouse--human hybrids in nude mice.

Four different human cell lines transformed by simian virus 40 (SV40) were tested for their tumorigenicity in athymic nude mice. Two of these lines, W18Va2 and GM52VA, were found to be tumorigenic when inoculated at a concentration of 1 x 10(7) cells per mouse. The other two cell lines, LN-SV and GM54VA, were found to induce very small tumors only after the injection of approximately 1 x 10(8) cells per mouse. Somatic cell hybrids between either LN-SV or GM54VA SV40-transformed human cells and normal mouse peritoneal macrophages, which have retained the human chromosomes carrying the SV40 genome, were found to be much more tumorigenic than the SV40-transformed human cell parents. These experiments suggest that the genetic background in which the human chromosomes carrying the SV40 genome are present plays a role in the modulation of the expiration of malignancy.

Animals↗
PubMed1977

Synteny of the genes for thymidine kinase and galactokinase in the mouse and their assignment to mouse chromosome 11.

We have studied the expression of mouse galactokinase in human-mouse somatic cell hybrids segregating mouse chromosomes. Since concordant segregation of the expression of mouse galactokinase and the presence of mouse chromosome 11 were observed in the hybrid clones, we conclude that the gene for mouse galactokinase is located on mouse chromosome 11. We have also investigated the expression of mouse galactokinase in somatic cell hybrids between thymidine kinase-deficient Chinese hamster cells and mouse peritoneal macrophages. The results of this study indicate that the expression of mouse galactokinase and thymidine kinase segregates concordantly, and, therefore, we infer that the gene for mouse thymidine kinase is also located on mouse chromosome 11.

Animals↗
PubMed1977

Assignment of the gene for glyoxalase I to region p21 leads to pter of human chromosome 6.

Using somatic cell hybrids between TK-deficient mouse cells and white blood cells derived from a patient with a translocation of the region p21 leads to pter of chromosome 17, we have assigned the gene for human GLO, to region p21 leads to pter of chromosome 6. Since the HLA region is only 10 cM distant from GLO, these results also confirm that the HLA region is located on the short arm of human chromosome 6.

Animals↗
PubMed1977

Assignment of the genes for human beta-glucuronidase and mitochondrial malate dehydrogenase to the region pter leads to q22 of chromosome 7.

In human fibroblast cultures derived from adults, clones of cells with a common chromosome rearrangement have been widely reported. Cells derived from one of these clones have been used in hybridization experiments using mouse cells to localize the genes for beta-glucuronidase and mitochondrial malate dehydrogenase on human chromosome 7. The results of this study indicate that the genes for these isozymes are located on the region pter leads to q22 of human chromosome 7.

Cell Line↗
PubMed1977

Somatic cell hybrids between mouse peritoneal macrophages and SV40-transformed human cells. III. Identification of surface antigens coded for by human chromosomes 7 and 17.

Somatic cell hybrids between SV40-transformed human cell lines and mouse peritoneal macrophages (MPM) containing either human chromosome 7 or 17 carrying the SV40 genome were injected into mice syngeneic to the mouse parental cells. Since either chromosome 7 or 17 was the only human chromosome present in the hybrids used as immunogens, the humoral immune response to gene products coded for by either chromosome was assayed. Using a sensitive radioimmunoassay, we were able to identify noncross-reactive cell-surface antigen(s) specifically coded for by either human chromosome 7 or 17, and present in normal, tumor-derived and virus-transformed human cells. However, no reactivity against SV40 tumor-specific surface antigen (TSSA) could be detected in the antisera.

Animals↗
PubMed1977

Antibody response to simian virus 40 tumor antigen in nude mice reconstituted with T cells.

Athymic BALB/c nude mice (nu/nu) fail to generate circulating antibodies to simian virus 40 (SV40) tumor (T) antigen when immunized with SV40-transformed mouse cells or with T antigen positive somatic cell hybrids derived from SV40-transformed human and normal mouse parental cells. However, normal BALB/c mice readily produce antibodies to SV40 T antigen. When nude mice were reconstituted with normal syngeneic T lymphocytes from spleen or thymus source, the humoral immune responsiveness to SV40 T antigen was restored.

Animals↗