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Previously, we cloned a cDNA fragment, TSIP 2 (tumor suppressor inhibited pathway clone 2), that detects by northern blot analysis of M1- LTR6 cells a 3-kb mRNA downregulated during p53-induced apoptosis. Cloning the full-length TSIP 2 cDNA showed that it corresponds to the presenilin 1 (PS1) gene, in which mutations have been reported in early-onset familial Alzheimer's disease. Here we demonstrate that PS1 is downregulated in a series of model systems for p53-dependent and p53-independent apoptosis and tumor suppression. To investigate the biological relevance of this downregulation, we stably transfected U937 cells with antisense PS1 cDNA. The downregulation of PS1 in these U937 transfectants results in reduced growth with an increased fraction of the cells in apoptosis. When injected into mice homozygous for severe combined immunodeficiency disease (scid/scid mice), these cells show a suppression of their malignant phenotype. Our results indicate that PS1, initially identified in a neurodegenerative disease, may also be involved in the regulation of cancer-related pathways., SCOPUS: ar.j, info:eu-repo/semantics/published

Previously, we cloned a cDNA fragment, TSIP 2 (tumor suppressor inhibited pathway clone 2), that detects by northern blot analysis of M1- LTR6 cells a 3-kb mRNA downregulated during p53-induced apoptosis. Cloning the full-length TSIP 2 cDNA showed that it corresponds to the presenilin 1 (PS1) gene, in which mutations have been reported in early-onset familial Alzheimer's disease. Here we demonstrate that PS1 is downregulated in a series of model systems for p53-dependent and p53-independent apoptosis and tumor suppression. To investigate the biological relevance of this downregulation, we stably transfected U937 cells with antisense PS1 cDNA. The downregulation of PS1 in these U937 transfectants results in reduced growth with an increased fraction of the cells in apoptosis. When injected into mice homozygous for severe combined immunodeficiency disease (scid/scid mice), these cells show a suppression of their malignant phenotype. Our results indicate that PS1, initially identified in a neurodegenerative disease, may also be involved in the regulation of cancer-related pathways., SCOPUS: ar.j, info:eu-repo/semantics/published

Interphasic nuclear organization has a key function in genome biology. We demonstrate that p21(WAF-1), by influencing gene expression and inducing chromosomal repositioning in tumor suppression, plays a major role as a nuclear organizer. Transfection of U937 tumor cells with p21(WAF-1) resulted in expression of the HUMSIAH (human seven in absentia homologue), Rb, and Rbr-2 genes and strong suppression of the malignant phenotype. p21(WAF-1) drastically modified the compartmentalization of the nuclear genome. DNase I genome exposure and fluorescence in situ hybridization show, respectively, a displacement of the sensitive sites to the periphery of the nucleus and repositioning of chromosomes 13, 16, 17, and 21. These findings, addressing nuclear architecture modulations, provide potentially significant perspectives for the understanding of tumor suppression., SCOPUS: ar.j, info:eu-repo/semantics/published

Developmentally regulated genes in Drosophila, which are conserved through evolution, are potential candidates for key functions in biological processes such as cell cycle, programmed cell death, and cancer. We report cloning and characterization of the human homologue of the Drosophila seven in absentia gene (HUMSIAH), which codes for a 282 amino acids putative zinc finger protein. HUMSIAH is localized on human chromosome 16q12-q13. This gene is activated during the physiological program of cell death in the intestinal epithelium. Moreover, human cancer-derived cells selected for suppression of their tumorigenic phenotype exhibit constitutively elevated levels of HUMSIAH mRNA. A similar pattern of expression is also displayed by the p21(waf1). These results suggest that mammalian seven in absentia gene, which is a target for activation by p53, may play a role in apoptosis and tumor suppression., SCOPUS: ar.j, info:eu-repo/semantics/published

Developmentally regulated genes in Drosophila, which are conserved through evolution, are potential candidates for key functions in biological processes such as cell cycle, programmed cell death, and cancer. We report cloning and characterization of the human homologue of the Drosophila seven in absentia gene (HUMSIAH), which codes for a 282 amino acids putative zinc finger protein. HUMSIAH is localized on human chromosome 16q12-q13. This gene is activated during the physiological program of cell death in the intestinal epithelium. Moreover, human cancer-derived cells selected for suppression of their tumorigenic phenotype exhibit constitutively elevated levels of HUMSIAH mRNA. A similar pattern of expression is also displayed by the p21(waf1). These results suggest that mammalian seven in absentia gene, which is a target for activation by p53, may play a role in apoptosis and tumor suppression., SCOPUS: ar.j, info:eu-repo/semantics/published

A model system is proposed to investigate, at the molecular level, the pathways of tumor suppression. As a tool for the selection of cells with a suppressed phenotype, we used the H-1 parvovirus that preferentially kills various neoplastic cells. From the human K562 leukemia cells, we isolated a clone, KS, that is resistant to the cytopathic effect of the H-1 virus and displays a suppressed malignant phenotype. The suppressed malignancy and the cellular resistance to H-1 killing appear to depend on the activity of wild-type p53. Whereas the KS cells express wild-type p53, the protein is undetectable in the parental K562 cells. Experiments with p53 mutants suggest that wild-type p53, in its functionally intact state, contributes to the resistance against the cytopathic effect of H-1 parvovirus., Journal Article, Research Support, Non-U.S. Gov't, SCOPUS: ar.j, info:eu-repo/semantics/published

A model system is proposed to investigate, at the molecular level, the pathways of tumor suppression. As a tool for the selection of cells with a suppressed phenotype, we used the H-1 parvovirus that preferentially kills various neoplastic cells. From the human K562 leukemia cells, we isolated a clone, KS, that is resistant to the cytopathic effect of the H-1 virus and displays a suppressed malignant phenotype. The suppressed malignancy and the cellular resistance to H-1 killing appear to depend on the activity of wild-type p53. Whereas the KS cells express wild-type p53, the protein is undetectable in the parental K562 cells. Experiments with p53 mutants suggest that wild-type p53, in its functionally intact state, contributes to the resistance against the cytopathic effect of H-1 parvovirus., Journal Article, Research Support, Non-U.S. Gov't, SCOPUS: ar.j, info:eu-repo/semantics/published

A putative tumor-suppressor gene (wt1) located at chromosome 11p13 and involved in Wilms' tumor development has recently been identified as a zinc finger polypeptide-encoding gene. The purpose of this study was to characterize the protein encoded by the human wt1 gene. The region spanning the entire zinc finger domain was amplified by polymerase chain reaction (PCR) and subcloned in the pATH 3 expression vector. Polyclonal antibodies against the fused TrpE-WT protein were raised. These antibodies immunoprecipitated a 49- to 51-kDa protein from hematopoietic tumor cells labeled in vivo with [35S]methionine. Subcellular fractionation and immunohistochemistry followed by confocal microscopy indicated that the Wilms' tumor gene product (WT1) is mainly localized within the nucleus., SCOPUS: ar.j, info:eu-repo/semantics/published

A putative tumor-suppressor gene (wt1) located at chromosome 11p13 and involved in Wilms' tumor development has recently been identified as a zinc finger polypeptide-encoding gene. The purpose of this study was to characterize the protein encoded by the human wt1 gene. The region spanning the entire zinc finger domain was amplified by polymerase chain reaction (PCR) and subcloned in the pATH 3 expression vector. Polyclonal antibodies against the fused TrpE-WT protein were raised. These antibodies immunoprecipitated a 49- to 51-kDa protein from hematopoietic tumor cells labeled in vivo with [35S]methionine. Subcellular fractionation and immunohistochemistry followed by confocal microscopy indicated that the Wilms' tumor gene product (WT1) is mainly localized within the nucleus., SCOPUS: ar.j, info:eu-repo/semantics/published

We measured the human pim-1 protooncogene (PIM) expression during fetal development and in hematopoietic malignancies. Our data indicate that during human fetal hematopoiesis the 33-kDa pim product, p33pim, is highly expressed in the liver and spleen. In contrast, at the adult stage it is only slightly expressed in circulating granulocytes. Out of 70 hematopoietic malignancies analyzed, 51 patients and 19 cell lines, p33pim was overexpressed in ~30% of the samples, particularly in myeloid and lymphoid acute leukemias. This overexpression was unrelated to any stage of cellular differentiation and was not due to gene rearrangement or amplification. These results imply a physiological role of the pim-1 protooncogene during hematopoietic development and a deregulation in various leukemias., SCOPUS: ar.j, info:eu-repo/semantics/published

Human chronic myelogenous leukemia is characterized by a reciprocal translocation between chromosomes 9 and 22. This results in the transfer of the c-abl protooncogene from chromosome 9 into the bcr gene on chromosome 2. The purpose of this study was to characterize the bcr and related gene products. Antibodies were raised against a fused trpE-bcr protein induced in a bacterial expression vector. Immunoprecipitation with the monoclonal and polyclonal antibodies of metabolically [35S]methionine labeled leukemic cell lines shows a 210, 160 and 130 Kda protein in Philadelphia positive cells containing the bcr-abl fused transcript. Only the 160 and 130 Kda were present in the Philadelphia negative cells. In vitro kinase assay shows that the 130 Kda protein is a phosphoprotein mainly phosphorylated on serine. Partial proteolysis indicates that the p210 and p130 share common domains. In subcellular fractionation experiments, the p130 is colocalized with the p210 bcr-abl in the cytoplasmic fraction. Together with the mapping of 4 distinct bcr related loci our data suggest that the 130 Kda phosphoprotein belongs to a wider family of bcr related gene products., SCOPUS: ar.j, info:eu-repo/semantics/published

Lactoferrin (LF) has been recently proposed as a physiologic regulator of the granulocyte monocyte progenitor (CFU-GM). This glycoprotein, when saturated with iron, has been said to limit CFU-GM growth by decreasing production and release of colony stimulating activity (CSA) by monocytes and macrophages. Human milk LF saturated with iron, at concentrations ranging from 10(-18) to 10(-8) M was added either to endogenously stimulated bone marrow cells or to mononucleated cells used as feeder layers for adherent cell-depleted marrow. Irrespective of the concentration of LF within the culture system used, no significant inhibition of CFU-GM growth was observed. Moreover, the CFU-GM stimulating activity of medium conditioned by a 4-day incubation of 1 X 10(6) mononucleated blood cells in the presence or in the absence of LF was the same. Various possible explanations for not confirming the reported inhibiting activity of iron saturated LF were explored: 1) masking inhibition of the system by prostaglandin E2 (PGE2), 2) masking inhibition of the system by bovine LF still detectable in the fetal calf serum after heating, 3) preinhibition of the system by leukemic-associated inhibitory activity (LIA) possibly present in the culture system, 4) the iron and calcium content of the culture medium used, 5) the fixation of LF to plastic compounds, 6) the source of the human LF used, 7) the marrow cell separation methods used. None of these factors was shown to play a role in vitro in the activity of LF and thus no evidence was found for a significant role of LF in the regulation of CSA production by monocytes. Peripheral blood human monocytes isolated by elutriation and incubated in albumin free medium in the presence of either 125I-LF or colloidal gold-labeled LF showed no LF binding., Comparative Study, Journal Article, Research Support, Non-U.S. Gov't, info:eu-repo/semantics/published

A 59-year-old woman, after complete recovery from an episode of drug-induced agranulocytosis, was found to sustain a chronic absence of recognizable mature and immature eosinophils in blood and bone marrow during a follow-up period of 8 years. Her bone marrow and peripheral blood cells cultured in vitro were able to produce normal numbers of eosinophil colonies. The present disorder was thus not caused by a lack of EO-CFU-C, nor by a defect in EO-CSA, nor by an immunologically mediated mechanism acting on mature or immature eosinophils or on EO-CSA producing cells. It is suggested that the marrow was not able to differentiate normally along the eosinophil pathway, possibly owing to a microenvironmental defect or, less likely, an intrinsic stem cell defect., Case Reports, Journal Article, Research Support, Non-U.S. Gov't, SCOPUS: ar.j, FLWNA, info:eu-repo/semantics/published

A patient with Mediterranean spotted fever presented an initial history of enteritis, pyrexia, and rash. He subsequently developed shock, multiple organ failure, thrombocytopenia, hypocalcemia with hypercalcitoninemia, and a euthyroid sick syndrome., Case Reports, Journal Article, SCOPUS: ar.j, SCOPUS: ar.j, info:eu-repo/semantics/published

A patient with Mediterranean spotted fever presented an initial history of enteritis, pyrexia, and rash. He subsequently developed shock, multiple organ failure, thrombocytopenia, hypocalcemia with hypercalcitoninemia, and a euthyroid sick syndrome., Case Reports, Journal Article, SCOPUS: ar.j, SCOPUS: ar.j, info:eu-repo/semantics/published

Lactoferrin (LF) has been recently proposed as a physiologic regulator of the granulocyte monocyte progenitor (CFU-GM). This glycoprotein, when saturated with iron, has been said to limit CFU-GM growth by decreasing production and release of colony stimulating activity (CSA) by monocytes and macrophages. Human milk LF saturated with iron, at concentrations ranging from 10(-18) to 10(-8) M was added either to endogenously stimulated bone marrow cells or to mononucleated cells used as feeder layers for adherent cell-depleted marrow. Irrespective of the concentration of LF within the culture system used, no significant inhibition of CFU-GM growth was observed. Moreover, the CFU-GM stimulating activity of medium conditioned by a 4-day incubation of 1 X 10(6) mononucleated blood cells in the presence or in the absence of LF was the same. Various possible explanations for not confirming the reported inhibiting activity of iron saturated LF were explored: 1) masking inhibition of the system by prostaglandin E2 (PGE2), 2) masking inhibition of the system by bovine LF still detectable in the fetal calf serum after heating, 3) preinhibition of the system by leukemic-associated inhibitory activity (LIA) possibly present in the culture system, 4) the iron and calcium content of the culture medium used, 5) the fixation of LF to plastic compounds, 6) the source of the human LF used, 7) the marrow cell separation methods used. None of these factors was shown to play a role in vitro in the activity of LF and thus no evidence was found for a significant role of LF in the regulation of CSA production by monocytes. Peripheral blood human monocytes isolated by elutriation and incubated in albumin free medium in the presence of either 125I-LF or colloidal gold-labeled LF showed no LF binding., Comparative Study, Journal Article, Research Support, Non-U.S. Gov't, info:eu-repo/semantics/published

A 59-year-old woman, after complete recovery from an episode of drug-induced agranulocytosis, was found to sustain a chronic absence of recognizable mature and immature eosinophils in blood and bone marrow during a follow-up period of 8 years. Her bone marrow and peripheral blood cells cultured in vitro were able to produce normal numbers of eosinophil colonies. The present disorder was thus not caused by a lack of EO-CFU-C, nor by a defect in EO-CSA, nor by an immunologically mediated mechanism acting on mature or immature eosinophils or on EO-CSA producing cells. It is suggested that the marrow was not able to differentiate normally along the eosinophil pathway, possibly owing to a microenvironmental defect or, less likely, an intrinsic stem cell defect., Case Reports, Journal Article, Research Support, Non-U.S. Gov't, SCOPUS: ar.j, FLWNA, info:eu-repo/semantics/published

We measured the human pim-1 protooncogene (PIM) expression during fetal development and in hematopoietic malignancies. Our data indicate that during human fetal hematopoiesis the 33-kDa pim product, p33pim, is highly expressed in the liver and spleen. In contrast, at the adult stage it is only slightly expressed in circulating granulocytes. Out of 70 hematopoietic malignancies analyzed, 51 patients and 19 cell lines, p33pim was overexpressed in ~30% of the samples, particularly in myeloid and lymphoid acute leukemias. This overexpression was unrelated to any stage of cellular differentiation and was not due to gene rearrangement or amplification. These results imply a physiological role of the pim-1 protooncogene during hematopoietic development and a deregulation in various leukemias., SCOPUS: ar.j, info:eu-repo/semantics/published

Human chronic myelogenous leukemia is characterized by a reciprocal translocation between chromosomes 9 and 22. This results in the transfer of the c-abl protooncogene from chromosome 9 into the bcr gene on chromosome 2. The purpose of this study was to characterize the bcr and related gene products. Antibodies were raised against a fused trpE-bcr protein induced in a bacterial expression vector. Immunoprecipitation with the monoclonal and polyclonal antibodies of metabolically [35S]methionine labeled leukemic cell lines shows a 210, 160 and 130 Kda protein in Philadelphia positive cells containing the bcr-abl fused transcript. Only the 160 and 130 Kda were present in the Philadelphia negative cells. In vitro kinase assay shows that the 130 Kda protein is a phosphoprotein mainly phosphorylated on serine. Partial proteolysis indicates that the p210 and p130 share common domains. In subcellular fractionation experiments, the p130 is colocalized with the p210 bcr-abl in the cytoplasmic fraction. Together with the mapping of 4 distinct bcr related loci our data suggest that the 130 Kda phosphoprotein belongs to a wider family of bcr related gene products., SCOPUS: ar.j, info:eu-repo/semantics/published

Monoclonal antibodies specific to human T lymphocyte receptors are currently being used to define the biochemical structure of these proteins as well as of functionally distinct cell subsets. Since one of the antibodies (OKT3) recognizing the T3 (CD3) receptor mimics vital physiological processes involved in the activation of the immune system and has been successfully used as a therapeutical agent, we invesigated one of the mechanisms underlying this antibody-receptor interaction. Our results show that after binding of OKT3, the complex (OKT3-T3) disappears rapidly from the cell surface. Using electron microscopy, we found that this down-regulation is due to the internalization of the complex. Parallel experiments performed on the T11 (CD2) and T4 (CD4)/AIDS retrovirus receptor indicate that the same mechanism applies for the down-regulation of those molecules. These data suggest that the T3, T11 and T4 receptors have a behavior comparable to other well characterized, hormonal and viral receptors; they provide information on the metabolization pathway of surface receptors and on the possible intracellular penetration of ligands like the HTLV-III/LAV agent in human T lymphocytes., SCOPUS: ar.j, FLWNA, info:eu-repo/semantics/published