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Biomedical subjects

N Rosen

Publications and source records attributed to N Rosen.

At least 109 records · Page 6Linked to original sources
PubMed1987

Growth regulation of human breast carcinoma occurs through regulated growth factor secretion.

We describe studies on human breast cancer in which it is shown that specific growth factors (IGF-I, TGF alpha, PDGF) are secreted by human breast cancer cells and likely to be involved in tumor growth and progression. These activities are regulated by estradiol in hormone-dependent breast cancer and secreted constitutively by hormone-independent cells. These growth factor activities can induce the growth of hormone-dependent cells in vivo in athymic nude mice. Hormone-dependent breast cancer cells also secrete TGF beta, a growth-inhibitory substance, when treated with antiestrogens. TGF beta functions as a negative autocrine growth regulator and is responsible for some of the growth-inhibitory effects of antiestrogens.

Animals↗
PubMed1987

Analysis of pp60c-src tyrosine kinase activity and phosphotyrosyl phosphatase activity in human colon carcinoma and normal human colon mucosal cells.

We have compared the level of phosphotyrosyl phosphatase activity in lysates from normal human colon mucosal cells and human colon carcinoma cells and analyzed the effect of incubating these cells with sodium orthovanadate, an inhibitor of phosphotyrosyl phosphatase activity, on the relative abundance of acid-stable phosphotyrosine and on in vitro protein kinase activity of pp60c-src. Additionally, we compared the effect of lysing these cells in buffer containing only nonionic detergents with RIPA buffer, which contains both sodium dodecyl sulfate and deoxycholate, on the in vitro kinase activity of pp60c-src. Our results show that the level of detectable phosphotyrosyl phosphatase activity in lysates derived from normal colon cells and colon carcinoma cells is very similar. Additionally, the abundance of acid-stable phosphotyrosine in these cells cultured in the absence or presence of vanadate is not significantly different. However, incubation of these cells with vanadate significantly stimulates the activity of pp60c-src derived from the normal colon cells in immune-complex kinase assays, while having no detectable effect on the activity of pp60c-src from the colon tumor cells. The in vitro protein kinase activity of pp60c-src derived from RIPA buffer lysates of colon carcinoma cells was found to be elevated five- to sevenfold when compared with pp60c-src from these same cells lysed in buffer containing only Nonidet-P 40 as a detergent. The type of lysis buffer did not effect the activity of pp60c-src from normal colon mucosal cells. These results provide additional evidence that the activity of pp60c-src may be regulated differently in colon carcinoma and normal colon mucosal cells.

Adenocarcinoma↗
PubMed1987

Philadelphia chromosome positive essential thrombocythemia evolving into lymphoid blast crisis.

The Philadelphia chromosome with the classic translocation t(9;22) was detected in all metaphases of a patient with essential thrombocythemia who presented without hematologic signs of chronic myeloid leukemia (CML). After 12 months of treatment with hydroxyurea followed by 6 months of busulfan, the disease transformed into lymphoid blast crisis with the immunophenotype of pre-pre-B cells frequently seen in lymphoid blast crisis of CML. This progression was not associated with karyotypic evolution because lymphoblasts contained only the Philadelphia chromosome. Further clinical course in this patient confirmed the development of a Philadelphia chromosome positive stem cell with predominantly megakaryocytic committment through partially megakaryocytic/lymphoid differentiation to purely lymphoid committment, a previously unreported transformation.

Adult↗
PubMed1987

Sirenomelia in a twelve weeks abortus.

The anatomical findings of sirenomelia in a 12-weeks aborted embryo are reported. The occurrence of sirenomelia in material from spontaneous abortions is discussed.

Abnormalities, Multiple↗
PubMed1987

Activation of pp60c-src protein kinase activity in human colon carcinoma.

The tyrosine-specific protein kinase activity of pp60c-src molecules obtained from human colon carcinoma tissues and tumor-derived cell lines was found to be elevated over that from normal colon tissues or cultures of normal colon mucosal cells. The elevated pp60c-src protein kinase activity in tumor tissues and in cultured colon carcinoma cells does not appear to result solely from an increase in the abundance of the c-src-encoded protein, suggesting that the specific activity of the pp60c-src tyrosine phosphotransferase is enhanced. These results raise the possibility that activation of the pp60c-src protein kinase may contribute to the genesis of human colon tumors.

Cell Line↗
PubMed1987

Fatal aplastic anemia in a child with Down's syndrome.

An infant with Down's syndrome developed severe persistent neutropenia at the age of 9 months and fluctuating anemia and thrombocytopenia at one year of age which terminated as full-blown aplastic anemia at 26 months of age. Immunological evaluation revealed increased peripheral and bone marrow lymphocytes and impaired blood OKT4: OKT8 ratio. Bone marrow granulocyte-macrophage colony forming cells (GM-CFC) were markedly increased, while peripheral blood mononuclear cells (PBMN) produced normal numbers of colonies. The patient's PBMN and serum were both somewhat inhibitory to normal bone marrow derived GM-CFC, suggesting the existence of a suppressor activity both in his serum and PBMN. This unusual course of aplastic anemia and the abnormalities in T-cells and hematopoiesis in Down's syndrome are discussed.

Anemia, Aplastic↗
PubMed1987

Analysis of pp60c-src in human colon carcinoma and normal human colon mucosal cells.

The tyrosine-specific protein kinase activity of pp60c-src molecules obtained from RIPA buffer lysates of human colon tumor-derived cell lines is elevated over that found in lysates from normal human colon mucosa cells. The elevation of pp60c-src kinase activity in the lysates of the cultured colon tumor cells does not appear to be the result of pp60c-src overexpression suggesting that the specific activity of the pp60c-src phosphotransferase may be enhanced. Cell-free translation of c-src mRNA from colon tumor cells and normal colon mucosa cells yielded pp60c-src molecules with similar levels of in vitro protein kinase activity suggesting that pp60c-src kinase activity in these cells may be regulated differently at a post-translational level. Analysis of pp60c-src molecules from normal colon and colon carcinoma cells revealed that they possessed indistinguishable sites and quantities of phosphorylated serine and tyrosine residues and were not detectably complexed with other cellular proteins. The activation of pp60c-src kinase activity in the colon tumor cells is associated with an apparent increase in the turnover rate of tyrosine-phosphates within the carboxyl terminal portion of the pp60c-src molecules from these tumor derived cell lines.

Colon↗
PubMed1987

Analysis of the c-src gene product structure, abundance, and protein kinase activity in human neuroblastoma and glioblastoma cells.

We have compared in different human neuroblastoma cell lines and human glioblastoma cells the expression level, structure, and tyrosine-specific protein kinase activity of pp60c-src. Our results show that not all human neuroblastoma cell lines express pp60c-src molecules with amino-terminal structural alterations. In neuroblastoma cells which possess pp60c-src with altered gel migration, the diminished polyacrylamide gel mobility of pp60c-src was found not to be dependent upon amino-terminal phosphorylations since extensive treatment of these molecules with phosphatase did not significantly change their gel migration properties. Similar differences in gel migration were observed when RNA from the various neuroblastoma and glioblastoma cells was translated in vitro using either rabbit reticulocyte or wheat germ lysates. White the level of c-src mRNA in the different cells analyzed was found to be similar, the abundance of pp60c-src in these same cells was found to vary by as much as 12-fold. This suggests that the abundance of pp60c-src in human neuroendocrine tumors is regulated through post-transcriptional and/or post-translational events which may be related to the stage of neuronal differentiation of the cells. Based upon determination of pp60c-src abundance by immunoblot analysis, we demonstrate that pp60c-src molecules derived from human neuroblastoma and glioblastoma cells have very similar in vitro protein kinase activities.

Antibodies, Monoclonal↗
PubMed1987

Sjögren's syndrome: severe upper airways obstruction due to primary malignant tracheal lymphoma developing during successful treatment of lymphocytic interstitial pneumonitis.

A wide spectrum of respiratory tract involvement may be seen in Sjögren's syndrome, however, multiple manifestations in one patient are unusual. A 65-year-old woman with a 5-year history of Sjögren's syndrome presented with hoarseness and pulmonary infiltrates. Lymphocytic interstitial pneumonitis, tracheobronchitis with subglottic edema and obstructive small airways disease were initially documented. Dramatic radiographic improvement of the lymphocytic interstitial pneumonitis occurred during 14 months of corticosteroid therapy. However, a rare primary malignant lymphoma of the trachea developed and presented with steroid refractory, upper airways obstruction. Subsequent patient management and the dichotomous behavior of the lymphoid infiltrates are discussed.

Aged↗
PubMed1986

Analysis of pp60c-src protein kinase activity in human tumor cell lines and tissues.

We have evaluated the level of pp60c-src protein kinase activity in a variety of human tumor tissues and human tumor cell lines, and have estimated the abundance of the c-src protein in several of these tissues and cell lines. All cell lines derived from tumors of neuroectodermal origin that express a neural phenotype were found to possess c-src molecules with high levels of tyrosine-specific protein kinase activity. In contrast, cell lines derived from tumors of neuroectodermal origin that do not express neural characteristics, such as glioblastomas and melanomas, were found to have pp60c-src molecules with low levels of protein kinase activity. A similar pattern was observed when we analyzed the activity of c-src molecules extracted directly from corresponding tumor tissues. Analysis of human tumor cell lines derived from tissues other than those of neuroectodermal origin revealed that pp60c-src protein kinase activity was low in most cases. Exceptions to this observation were all rhabdomyosarcoma, osteogenic sarcoma, Ewing's sarcoma, and colon carcinoma lines tested. Comparison of pp60c-src kinase activity in normal skeletal muscle and rhabdomyosarcoma tissue and in normal breast tissue and breast adenocarcinoma tissue revealed that pp60c-src kinase activity was specifically elevated in the tumor tissues in both cases. However, the amount of pp60c-src protein in both normal and tumor tissues was found to be similar. These observations suggest that increases in the specific activity of the pp60c-src phosphotransferase in some rhabdomyosarcomas and breast carcinomas may be a characteristic acquired during the malignant transformation of the cells that is retained in cell lines established from these tumors.

Cell Line↗
PubMed1986

Increased N-myc expression following progressive growth of human neuroblastoma.

Many human neuroblastoma tumors and cells in culture contain amplified N-myc DNA and this is associated with tumor stage. We have analyzed pairs of neuroblastoma cell cultures derived from two patients at the time of diagnosis and after tumor progression following the initiation of therapy. Cell cultures derived after progression have increased expression of N-myc RNA. In one pair this increase is associated with increased N-myc DNA amplification; in the other, amplification decreases and activation of N-myc is most likely the result of a regulatory change. Analysis of the pattern of DNA amplification in these cell cultures demonstrates additional changes that might be associated with tumor progression.

Base Sequence↗
PubMed1985

Increased pp60c-src tyrosyl kinase activity in human neuroblastomas is associated with amino-terminal tyrosine phosphorylation of the src gene product.

We have observed a 20- to 40-fold increase in pp60c-src tyrosyl kinase activity in human neuroblastoma cell lines over that found in either human glioblastoma cells or human fibroblasts. The level of c-src gene transcripts and pp60c-src protein synthesis in the neuroblastoma cells was not significantly increased when compared to the levels found in glioblastoma cells. Approximately one-half of the pp60c-src molecules synthesized during a 4-hr [35S]methionine or [32P]orthophosphate labeling period in neuroblastoma cells were found to migrate more slowly on NaDodSO4/polyacrylamide gels than pp60c-src molecules labeled in glioblastoma cells. Peptide and phosphoamino acid analysis of the in vivo phosphorylated c-src molecules from these two cell types revealed that pp60c-src molecules from the neuroblastoma cells possess in the amino-terminal portion of the protein at least one unique tyrosine phosphorylation site not found in pp60c-src derived from glioblastoma cells.

Cell Line↗