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. 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. 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.

Kinetic parameters of hexose transport in hybrids between malignant and nonmalignant cells

1983 ◽  
Vol 62 (1) ◽  
pp. 49-80
Author(s):  
M.K. White ◽  
M.E. Bramwell ◽  
H. Harris
Keyword(s):  
Kinetic Parameters ◽  
Malignant Cell ◽  
Hexose Transport ◽  
Hybrid Cells ◽  
Michaelis Constant ◽  
Independent Measurement ◽  
The Difference ◽  
Hexose Uptake ◽  
Derivatives Of

Matched pairs of isogeneic hybrid cells, in which one member of the pair was malignant and the other not, were used to examine the linkage between malignancy and functional alterations in hexose transport. The kinetic parameters of uptake of 2-deoxy-D-glucose were measured in a range of such hybrids, both human and murine. Some other malignant cell lines were also examined and were compared with non-tumorigenic derivatives of tumour cells selected by exposure to the lectin, wheat-germ agglutinin. In every case, malignancy, as defined by the ability of cells to grow progressively in vivo, was found to be linked to a decrease in the Michaelis constant of hexose uptake. Independent measurement of the transport and phosphorylation reactions involved in hexose uptake revealed that this decrease was determined by the membrane transport system. The difference in Michaelis constant between malignant and non-malignant cells was observed with 3-O-methylglucose, a hexose that is transported into the cell but not further metabolized. The activity of hexokinase in cell homogenates was higher than the level that would be required to cope with transport and showed no correlation with tumorigenicity. Measurement of the uptake of D-glucose itself, by a rapid filtration centrifugation method, gave results similar to those obtained with 2-deoxy-D-glucose.

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.

The development of a computational machine learning tool to decipher malignant cell gene expression from complex tumor tissue.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e15050-e15050
Author(s):  
Maksim Chelushkin ◽  
Valentina Beliaeva ◽  
Aleksandr Zaitsev ◽  
Boris Shpak ◽  
Krystle Nomie ◽  
...  
Keyword(s):  
Gene Expression ◽  
Correlation Coefficient ◽  
Cell Lines ◽  
Cancer Cell ◽  
Tumor Tissue ◽  
Malignant Cell ◽  
Cancer Cell Lines ◽  
Malignant Cells ◽  
Cell Expression

e15050 Background: Complex tumor tissue is composed of malignant cells and diverse tumor microenvironment (TME) cellular populations. Depending on the cancer type, the percentage of malignant cells present in tumor tissue varies, with percentages sometimes below 10%. TME cellular transcripts may comprise the majority of the total transcripts in a tumor, potentially resulting in biases during biomarker development and for clinical decision-making. However, TME gene expression can be subtracted from total tumor gene expression, resulting in only malignant cell expression. Methods: A computational tool was developed for the “subtraction” of TME-specific gene expression from total gene expression in an array of solid tumors, producing in silico “purified'' malignant cell gene expression. To extract the malignant cell RNA expression values, a machine learning model was trained on an artificial transcriptome dataset created from different solid tumor cancer cell lines with the addition of various TME cellular proportions. The artificial transcriptomes, both training and test, were composed of 7,114 samples of purified TME cell types and 3,143 cancer cell lines. The final model relied on the following three major parameters: 1) RNA percentages of deconvolved TME cell types; 2) the weighted sum of the average expression of a malignant cell target gene produced by different TME cell populations where the RNA percentages (weights in the weighted sum) of the TME cell populations were predicted by deconvolution; and 3) a set of genes expressed predominantly in the TME. To experimentally validate the computational model, different proportions of COLO829 (cutaneous melanoma), MCF-7 (invasive ductal carcinoma), and K562 (chronic myeloid leukemia) cell lines were mixed in vitro with PBMCs, creating controlled representations of tumor tissue, and RNA was extracted and sequenced. Gene expression was quantified and analyzed with the computational model, with comparisons to pure cancer cell line expression. Results: The expression of at least 120 clinically relevant biomarkers was reconstructed by applying the model to artificial transcriptomes in which the percentage of malignant cells varied from 10% to 90%. The concordance correlation coefficient between pure cancer cell lines and the extracted malignant cell expression increased on average from 0.75 to 0.9 compared to unprocessed data (e.g., PTEN from 0.2 to 0.88, RB1 from 0.57 to 0.89, ERBB2 from 0.83 to 0.99). In vitro validation showed that the tool improved the concordance correlation coefficient and mean absolute error (MAE) for many tumor biomarkers. For example, the PTEN correlation coefficient increased by 0.33 and its MAE was reduced 3-fold. Conclusions: This novel computational tool can aid in treatment decision-making based on malignant cell expression, promoting the use of gene expression for personalized therapeutics.

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 anticancer agent PB-100, selectively active on malignant cells, inhibits multiplication of sixteen malignant cell lines, even multidrug resistant

2000 ◽  
Vol 23 (1) ◽  
pp. 29-33 ◽  
Author(s):  
Mirko Beljanski
Keyword(s):  
Cancer Cells ◽  
Tumor Cells ◽  
Cell Lines ◽  
Plant Extract ◽  
Normal Cell ◽  
Anticancer Agent ◽  
Malignant Cell ◽  
Multidrug Resistant ◽  
Cell Multiplication ◽  
Malignant Cells

The plant-derived anticancer agent PB-100 selectively destroys cancer cells, even when multidrug resistant; yet, it does not inhibit normal (non-malignant) cell multiplication. Testing of PB-100 on sixteen malignant cell lines, several multidrug resistant, as well as on five normal cell lines, confirmed our previous results. Flavopereirine and dihydroflavopereirine, the active principles of PB-100, were chemically synthesized and displayed the same selectivity for tumor cells as the purified plant extract, being active at even lower concentrations.

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.

scholarly journals Expression and hypoxia-responsiveness of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 4 in mammary gland malignant cell lines.

2005 ◽  
Vol 52 (4) ◽  
pp. 881-888 ◽  
Author(s):  
Oleksandr H Minchenko ◽  
Iryna L Opentanova ◽  
Tsutomu Ogura ◽  
Dmytro O Minchenko ◽  
Sergiy V Komisarenko ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mammary Gland ◽  
Cancer Cells ◽  
Cell Lines ◽  
Specific Inhibitor ◽  
T47d Cell ◽  
Malignant Cell ◽  
Malignant Cells ◽  
Protein Levels ◽  
Mammary Gland Cancer

Recently, we have shown that PFKFB4 gene which encodes the testis isoenzyme of PFKFB is also expressed in the prostate and hepatoma cancer cell lines. Here we have studied expression and hypoxic regulation of the testis isoenzyme of PFKFB4 in several malignant cell lines from a female organ--the mammary gland. Our studies clearly demonstrated that PFKFB4 mRNA is also expressed in mammary gland malignant cells (MCF-7 and T47D cell lines) in normoxic conditions and that hypoxia strongly induces it expression. To better understand the mechanism of hypoxic regulation of PFKFB4 gene expression, we used dimethyloxalylglycine, a specific inhibitor of HIF-1alpha hydroxylase enzymes, which strongly increases HIF-1alpha levels and mimics the effect of hypoxia. It was observed that PFKFB4 expression in the MCF7 and T47D cell lines was highly responsive to dimethyloxalylglycine, suggesting that the hypoxia responsiveness of PFKFB4 gene in these cell lines is regulated by HIF-1 proteins. Moreover, desferrioxamine and cobalt chloride, which mimic the effect of hypoxia by chelating or substituting for iron, had a similar stimulatory effect on the expression of PFKFB mRNA. In other mammary gland malignant cell lines (BT549, MDA-MB-468, and SKBR-3) hypoxia and hypoxia mimics also induced PFKFB4 mRNA, but to variable degrees. The hypoxic induction of PFKFB4 mRNA was equivalent to the expression of PFKFB3, Glut1, and VEGF, which are known HIF-1-dependent genes. Hypoxia and dimethyloxalylglycine increased the PFKFB4 protein levels in all cell lines studied except MDA-MB-468. Through site-specific mutagenesis in the 5'-flanking region of PFKFB4 gene the hypoxia response could be limited. Thus, this study provides evidence that PFKFB4 gene is also expressed in mammary gland cancer cells and strongly responds to hypoxia via an HIF-1alpha dependent mechanism. Moreover, the PFKFB4 and PFKFB3 gene expression in mammary gland cancer cells has also a significant role in the Warburg effect which is found in all malignant cells.

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