PHOSPHODIPEPTIDE ANALYSIS OF NONHISTONE NUCLEAR PROTEINS FROM NOVIKOFF HEPATOMA ASCITES CELLS

Dark field electron microscopy has been used for the study of the structure of individual macromolecules with a resolution to at least the 5Å level. The use of this technique has been extended to the investigation of structure of interacting molecules, particularly the interaction between DNA and fish protamine, a class of basic nuclear proteins of molecular weight 4,000 daltons.Protamine, which is synthesized during spermatogenesis, binds to chromatin, displaces the somatic histones and wraps up the DNA to fit into the small volume of the sperm head. It has been proposed that protamine, existing as an extended polypeptide, winds around the minor groove of the DNA double helix, with protamine's positively-charged arginines lining up with the negatively-charged phosphates of DNA. However, viewing protamine as an extended protein is inconsistent with the results obtained in our laboratory.

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Nuclear proteins in primary biliary cirrhosis as guardians against HCC development

Zeitschrift für Gastroenterologie ◽

10.1055/s-0032-1332068 ◽

2013 ◽

Vol 51 (01) ◽

Author(s):

C Hintemann ◽

K Straub ◽

S Biesterfeld ◽

PR Galle ◽

J Erthle ◽

...

Keyword(s):

Primary Biliary Cirrhosis ◽

Nuclear Proteins ◽

Biliary Cirrhosis

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Die Anämie bei malignen Tumorerkrankungen

Nuklearmedizin ◽

10.1055/s-0038-1629498 ◽

1989 ◽

Vol 28 (06) ◽

pp. 247-254

Author(s):

E. Aulbert

Keyword(s):

Malignant Tumors ◽

Gradient Centrifugation ◽

Tumor Resection ◽

Hemoglobin Concentration ◽

Limiting Factor ◽

Novikoff Hepatoma ◽

Tumor Mass ◽

Lysosomal Fraction ◽

Proliferation Activity ◽

Morris Hepatoma

The cellular uptake and lysosomal accumulation of 67Ga-labelled transferrin within tumors of different malignancy were examined using tissue fractionation and immunological techniques. As tumor models the slowly growing Morris hepatoma 5123C, the moderately growing Novikoff hepatoma and the fast and aggressive Yoshida hepatoma AH 130 were investigated. Isolation of subcellular fractions of tumor homogenates was performed by differential centrifugation and density-gradient centrifugation. The intracellular 67Gatransferrin was found to be highly concentrated within the purified lysosomes. The transferrin within the lysosomal fraction was identified by radial immunodiffusion technique using monospecific antiserum. The accumulation of 67Gatransferrin by the tumors resulted in a faster disappearance of 67Ga-transferrin from the blood. This loss of circulating 67Ga-transferrin correlated with the proliferation activity and the spread of the tumors. Since transferrin is indispensible for the utilization of iron by the heme-synthesizing red cell precursors, transferrin concentration in the blood is the limiting factor for the utilization of iron in hemoglobin synthesis. Thus, in a further series of experiments we investigated the development of anemia in tumor-bearing rats. With increasing tumor mass a progressive fall of hemoglobin concentration was found. The anemia was more severe in the faster growing Novikoff hepatoma than in the slowly growing Morris hepatoma. The most significant reduction of hemoglobin concentration was found in the very fast growing Yoshida hepatoma. After total tumor resection hemoglobin concentration and red blood cell count normalized completely within 6-8 weeks. We conclude from these data that the uptake of transferrin by the tumor cells results in a faster disappearance of transferrin from the blood. This loss of circulating transferrin correlates with tumor mass and proliferation activity and is one of the factors responsible for the anemia seen in patients with malignant tumors.

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Die Anämie bei malignen Tumorerkrankungen

Nuklearmedizin ◽

10.1055/s-0038-1629491 ◽

1989 ◽

Vol 28 (05) ◽

pp. 193-200 ◽

Cited By ~ 1

Author(s):

E. Aulbert

Keyword(s):

Cellular Uptake ◽

Tumor Tissue ◽

Malignant Tumors ◽

The Other ◽

Novikoff Hepatoma ◽

Cellular Accumulation ◽

Tumor Mass ◽

Proliferation Activity ◽

Morris Hepatoma ◽

Cellular Incorporation

Cellular uptake of 67Ga-labelled transferrin by the tumor tissue was studied in rats with tumors of different malignancy and different tumor mass using the slowly growing Morris hepatoma 5123C, the moderately growing Novikoff hepatoma and the very fast and aggressive Yoshida hepatoma AH130. The cellular accumulation of 67Ga-transferrin was found to correlate with the proliferation activity of the tumor. The 67Ga-transferrin concentration in the very fast growing Yoshida hepatoma was 4.8 times higher than the concentration in the slowly growing Morris hepatoma. The uptake of 67Ga-transferrin by the tumors resulted in a faster disappearance of circulating 67Ga-transferrin from the blood. The rate of disappearance correlated with the proliferation activity and the spread of the tumors. Using tumors of identical size the elimination of 67Ga-transferrin from the blood was much faster in the rats with Yoshida hepatoma than in those with the slowly growing Morris hepatoma. On the other hand, using tumors of different tumor size it could be demonstrated that the rate of disappearance of 67Ga-transferrin from the blood correlated directly with tumor mass. It is concluded that cellular incorporation of transferrin within the tumor cells results in a loss of circulating transferrin, which correlates with tumor mass and proliferation of tumor. This mechanism is supposed to be the cause for the hypotransferrinemia seen in patients with malignant tumors.

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GENE ACTIVATION IN MAMMARY CELLS

Acta Endocrinologica ◽

10.1530/acta.0.071s346 ◽

1972 ◽

Vol 71 (2_Suppla) ◽

pp. S346-S368 ◽

Cited By ~ 4

Author(s):

Roger W. Turkington ◽

Nobuyuki Kadohama

Keyword(s):

Cell Differentiation ◽

Gene Transcription ◽

Hormonal Regulation ◽

Gene Activation ◽

Milk Proteins ◽

Mouse Mammary Gland ◽

Nuclear Proteins ◽

Mammary Cells ◽

Alveolar Cells ◽

Mammary Cell

ABSTRACT Hormonal activation of gene transcription has been studied in a model system, the mouse mammary gland in organ culture. Transcriptive activity is stimulated in mammary stem cells by insulin, and in mammary alveolar cells by prolactin and insulin. Studies on the template requirement for expression of the genes for milk proteins demonstrate that DNA methylation has an obligatory dependence upon DNA synthesis, but is otherwise independent from hormonal regulation of mammary cell differentiation. Incorporation of 5-bromo-2′deoxyuridine into DNA selectively inhibits expression of the genes for specific milk proteins. Undifferentiated mammary cells activate the synthesis of specific acidic nuclear proteins when stimulated by insulin. Several of these induced acidic nuclear proteins are undetectable in unstimulated undifferentiated cells, but appear to be characteristic components of the nuclei of differentiated cells. These results indicate that mammary cell differentiation is associated with a change in acidic nuclear proteins, and they provide evidence to support the concept that acidic nuclear proteins may be involved in the regulation of gene transcription and of mammary cell differentiation.

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