Studies on the surface properties of hybrid cells. I. Sialyl-transferase activity in homogenates of malignant and non-malignant cells

1980 ◽  
Vol 46 (1) ◽  
pp. 187-201
Author(s):  
M.A. Atkinson ◽  
M.E. Bramwell
Keyword(s):  
Tissue Culture ◽  
Sialic Acid ◽  
Elevated Level ◽  
Malignant Cell ◽  
Cell Populations ◽  
Transferase Activity ◽  
Malignant Cells ◽  
Hybrid Cells ◽  
Cell Homogenate ◽  
Wide Range

We report here a method for the assay of the sialyl-transferase activity in crude homogenates of a wide range of cell lines growing in tissue culture. Our results indicate that particulate preparations from both malignant and non-malignant cells show a Km of 0.25 mM towards CMP-sialic acid in the presence of an excess of glycoprotein acceptor. There appear to be increased amounts of the enzyme associated with the preparations from malignant sources which are reflected in an increase in the apparent Vmax of these. The elevated level of sialyl-transferase activity seen in the malignant cell populations is, paradoxically, associated with a decrease in the amount of bound sialic acid associated with both the whole cell homogenate preparations and the surface of these cells.

Studies on the surface properties of hybrid cells. II. Sialyl-transferase activity on the surface of malignant and non-malignant cells

1980 ◽  
Vol 46 (1) ◽  
pp. 203-220
Author(s):  
M.A. Atkinson ◽  
M.E. Bramwell
Keyword(s):  
Surface Properties ◽  
Surface Activity ◽  
Cell Lines ◽  
Plasma Membranes ◽  
Malignant Cell ◽  
Transferase Activity ◽  
Malignant Cells ◽  
Hybrid Cells ◽  
Wide Range ◽  
The Difference

A measurable surface activity of sialyl-transferase is demonstrated by a number of different methods to exist on the plasma membranes of both malignant and non-malignant cells. The amount of enzyme present on the surface of malignant cells is found to be higher than that on the non-malignant ones in a wide range of malignant and non-malignant cell lines. It is proposed that the difference in apparent activity results in part from the presence of incomplete glycoproteins in the surface membranes of the malignant cells and in part from an increased rate of membrane synthesis in these cells.

Studies on the surface properties of hybrid cells. III. A membrane glycoprotein found on the surface of a wide range of malignant cells

1981 ◽  
Vol 48 (1) ◽  
pp. 147-170
Author(s):  
M.A. Atkinson ◽  
M.E. Bramwell
Keyword(s):  
Sialic Acid ◽  
Molecular Mass ◽  
Surface Properties ◽  
Apparent Molecular Mass ◽  
Membrane Glycoprotein ◽  
Malignant Cells ◽  
Hybrid Cells ◽  
Wide Range

We report here the presence of a glycoprotein of apparent molecular mass 90000 daltons on the surface of membranes of malignant cells, which is absent or very much reduced on the surface of non-malignant cells. This glycoprotein is rich in sialic acid and appears to be sensitive to the concentration of cAMP under certain conditions. Analysis of the labelled sugars present in the glycoproteins of cells metabolically labelled with [14C]glucosamine suggests that all the enzymes necessary for the conversion of the tracer precursor into the sugars normally found to be labelled are present in both the malignant and the non-malignant cells.

The Analysis of Malignancy by Cell Fusion

1971 ◽  
Vol 8 (3) ◽  
pp. 659-672
Author(s):  
G. KLEIN ◽  
U. BREGULA ◽  
F. WIENER ◽  
H. HARRIS
Keyword(s):  
Cell Line ◽  
Tumour Cell ◽  
Malignant Cell ◽  
Hybrid Cells ◽  
Metabolic Defects ◽  
L Cell ◽  
Wide Range ◽  
Derivatives Of ◽  
Selection Of

A wide range of different kinds of malignant cell were fused with certain derivatives of the L cell line and the ability of the resulting hybrid cells to grow progressively in vivo was examined. In all cases the highly malignant character of the tumour cells was suppressed by fusion with the L cell derivatives, whether or not these had metabolic defects that facilitated selection of the hybrid cells. So long as the hybrid cells retained the complete chromosome complements of the two parent cells, their ability to grow progressively in vivo was very limited, for tumours composed of such unreduced hybrids were not found. However, when they lost certain specific, but as yet unidentified, chromosomes, the hybrid cells regained the ability to grow progressively in vivo and gave rise to a tumour. These findings thus indicated that the L cell derivatives contributed something to the hybrid that suppressed the malignancy of the tumour cell, and that this contribution was lost when certain specific chromosomes were eliminated.

The Analysis of Malignancy by Cell Fusion

1974 ◽  
Vol 16 (1) ◽  
pp. 189-198
Author(s):  
F. WIENER ◽  
G. KLEIN ◽  
H. HARRIS
Keyword(s):  
Cell Fusion ◽  
Tumour Cells ◽  
Complementation Analysis ◽  
Malignant Cells ◽  
Hybrid Cells ◽  
Malignant Phenotype ◽  
Recessive Character ◽  
Parental Chromosome ◽  
Wide Range

Previous studies with a variety of transplantable mouse tumours showed that in hybrids between malignant and non-malignant cells, malignancy behaved as a recessive character: the hybrid cells, so long as they retained something close to the complete parental chromosome sets, had little or no ability to grow progressively in vivo. In the experiments we now describe the heritable lesions determining the malignant phenotype were further explored by complementation analysis in which the various tumour cells were fused with each other. Forty-two clonal populations derived from twelve crosses between different kinds of tumour cells were examined. Only one cross generated hybrid cells with reduced tumorigenicity: in all other cases the hybrid cells formed were highly malignant. It thus appears that, in a wide range of different tumours, the lesions determining the malignant phenotype, although recessive, fail to complement each other.

scholarly journals Suppression of malignancy in hybrid cells: the mechanism

1985 ◽  
Vol 79 (1) ◽  
pp. 83-94 ◽  
Author(s):  
H. Harris
Keyword(s):  
Extracellular Matrix ◽  
Terminal Differentiation ◽  
Parent Cell ◽  
Malignant Cells ◽  
Hybrid Cells ◽  
Malignant Phenotype ◽  
Diploid Parent ◽  
Wide Range ◽  
Secondary Consequence

When malignant cells, defined by their ability to grow progressively in genetically compatible hosts, are fused with diploid fibroblasts of the same species, the resulting hybrid cells, so long as they retain certain specific chromosomes donated by the diploid parent cell, are non-malignant. When these particular chromosomes are eliminated from the hybrid, the malignant phenotype reappears, and the segregant cell is again able to grow progressively in vivo. In the present experiments the histological character of the lesions produced by the inoculation of crosses between malignant and non-malignant cells was examined. It was found, in a wide range of material, and without exception, that where one or other of the parent cells in the cross was of fibroblastic lineage, malignancy was suppressed when the hybrid cells produced a collagenous extracellular matrix in vivo; and it reappeared when genetic segregants were produced that had lost the ability to produce this matrix. These results are interpreted in terms of a general model in which it is proposed that the progressive multiplication of malignant cells in vivo is a secondary consequence of a genetically stable impairment of terminal differentiation.

scholarly journals The electrophoretic mobility of normal and leukaemic cells of mice

1968 ◽  
Vol 107 (4) ◽  
pp. 549-557 ◽  
Author(s):  
G. M. W. Cook ◽  
W. Jacobson
Keyword(s):  
Sialic Acid ◽  
Malignant Cell ◽  
Carboxyl Group ◽  
Malignant Cells ◽  
Acidic Group ◽  
Before And After ◽  
Leukaemic Cells ◽  
Lymph Node Cells ◽  
The Difference ◽  
The Stability

1. The pH–mobility relationships for saline-washed cells from a mouse strain of acute lymphoblastic leukaemia were examined before and after treatment with lower aldehydes, diazomethane and neuraminidase (EC 3.2.1.18). 2. The content of sialic acid released into the supernatant fluid of neuraminidase-treated cells was measured. 3. The stability of the charge-determining structures to temporary changes in environment (pH and ionic strength) was established. 4. Similar measurements were made on lymph-node cells obtained from non-leukaemic mice (a resistant and a leukaemia-susceptible strain were examined). 5. It is deduced that both the malignant and the non-malignant cell possess two dissociable acid functions at the cell surface, a carboxyl group of sialic acid and another acidic group(s), probably carboxyl, of pK 3·0–4·5. The malignant cells, however, have a basic dissociable function not present in the non-malignant types. 6. Suggestions are made as to how the difference in surface chemistry may be related to the problem of malignancy.

An abnormal membrane glycoprotein associated with malignancy in a wide range of different tumours

1978 ◽  
Vol 201 (1142) ◽  
pp. 87-106 ◽  
Keyword(s):  
Tumour Cell ◽  
Cell Populations ◽  
Structural Abnormality ◽  
Membrane Glycoprotein ◽  
Malignant Cells ◽  
Wide Range

Malignancy, as measured by the ability of cells to grow progressively in vivo , is intimately linked to the presence of a structural abnormality in the polysaccharide moiety of one particular membrane glycoprotein. This abnormality is present in a wide range of different tumours; it co-segregates with malignancy in all crosses between malignant and non-malignant cells that have so far been tested; and it remains linked to malignancy in a stringent new test in which non-malignant variants are selected from tumour cell populations by the use of a lectin.

scholarly journals Alterations induced by glucose deprivation and tunicamycin in the kinetic parameters of hexose transport in hybrid cells

1984 ◽  
Vol 68 (1) ◽  
pp. 257-270
Author(s):  
M.K. White ◽  
M.E. Bramwell ◽  
H. Harris
Keyword(s):  
Maximum Velocity ◽  
Glucose Deprivation ◽  
Malignant Cell ◽  
Matched Pairs ◽  
Hexose Transport ◽  
Malignant Cells ◽  
Hybrid Cells ◽  
Membrane Glycoproteins ◽  
Michaelis Constant ◽  
Hexose Uptake

Matched pairs of malignant and non-malignant hybrid cells were compared in their response to glucose deprivation and to tunicamycin. Glucose deprivation induced an increase in the maximum velocity in the malignant cells, but not in the non-malignant cells. The Michaelis constant of hexose uptake was largely unchanged by glucose deprivation except in the case of one melanoma derivative, PG19 G-, which showed a large increase in Michaelis constant when deprived of glucose. Tunicamycin increased the Michaelis constant of hexose uptake in both malignant and non-malignant cell lines. It is therefore possible that the Michaelis constant of hexose uptake is affected by the extent of glycosylation of one or more of the cell membrane glycoproteins.

scholarly journals Sialic Acid—Modified Nanoparticles—New Approaches in the Glioma Management—Perspective Review

2021 ◽  
Vol 22 (14) ◽  
pp. 7494
Author(s):  
Przemyslaw Wielgat ◽  
Katarzyna Niemirowicz-Laskowska ◽  
Agnieszka Z. Wilczewska ◽  
Halina Car
Keyword(s):  
Sialic Acid ◽  
Clinical Observation ◽  
Malignant Cell ◽  
Cellular Heterogeneity ◽  
Molecular Processes ◽  
Management Perspective ◽  
Therapeutic Tools ◽  
And Function ◽  
Worse Prognosis

The cell surface is covered by a dense and complex network of glycans attached to the membrane proteins and lipids. In gliomas, the aberrant sialylation, as the final stage of glycosylation, is an important regulatory mechanism of malignant cell behavior and correlates with worse prognosis. Better understanding of the role of sialylation in cellular and molecular processes opens a new way in the development of therapeutic tools for human brain tumors. According to the recent clinical observation, the cellular heterogeneity, activity of brain cancer stem cells (BCSCs), immune evasion, and function of the blood–brain barrier (BBB) are attractive targets for new therapeutic strategies. In this review, we summarize the importance of sialic acid-modified nanoparticles in brain tumor progression.

DNA Content of Normal and Neoplastic Urothelial Cells

1980 ◽  
Vol 66 (4) ◽  
pp. 445-458 ◽  
Author(s):  
Mathilde E. Boon
Keyword(s):  
Dna Content ◽  
Cell Populations ◽  
Malignant Cells ◽  
Urothelial Cells ◽  
Chromatin Pattern ◽  
Normal Bladder ◽  
Well Differentiated ◽  
Dna Measurements ◽  
Combined Parameters ◽  
Umbrella Cells

In search for suitable parameters to detect neoplastic urothelial cells in Acriflavine-Feulgen-SITS stained specimen we compared the cytofluorometric DNA content with the morphology of normal urothelial cells (bladder scrapings) and neoplastic urothelial cells from grade 1, 2, 3 and 4 tumors. An individual normal urothelial cell could not be distinguished from a grade 1 tumor cell, neither morphologically nor fluorometrically. However, the shape of the histograms of DNA measurements of the cell populations of respectively normal bladder scrapings and grade 1 tumors differs. It is postulated that also morphometry of these cell populations may be of some aid to distinguish well-differentiated neoplastic cells from normal urothelial cells. Seventy-one percent of the morphologically malignant cells in the grade 2, 3 and 4 tumor samples could be identified by applying the combined parameters: high DNA content (> 5 C) and nuclear-cytoplasmic ratio (> 0.5) and all grade 2, 3 and 4 tumor samples contained cells which were objectively classified as malignant. Using the same parameters morphologically malignant cells could be distinguished from normal, polyploid umbrella cells, thus these malignant cells are detectable objectively without using chromatin pattern as parameter.

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