The Analysis of Malignancy by Cell Fusion

1971 ◽  
Vol 8 (3) ◽  
pp. 681-692
Author(s):  
F. WIENER ◽  
G. KLEIN ◽  
H. HARRIS
Keyword(s):  
Tumour Cells ◽  
Hybrid Cells ◽  
Recessive Character ◽  
Parental Chromosome ◽  
Diploid Fibroblasts ◽  
Progressive Loss ◽  
L Cell ◽  
Very High

Diploid fibroblasts were fused with cells of two highly malignant near euploid tumours, a sarcoma induced by polyoma virus and a spontaneous carcinoma; the resulting hybrid cells were tested for their ability to grow progressively in vivo. In the case of the sarcoma/fibroblast hybrids, 15 clonal populations, each derived from a separate primary fusion, were examined. Most of these populations already showed substantial losses of chromosomes by the time enough cells had been generated to permit chromosomal analysis; but a few clones were isolated with chromosomal constitutions approximating to the sum of the 2 parental chromosome sets. Those clones that had undergone substantial chromosomal losses were highly tumorigenic, but some of the clones that contained the complete, or almost complete, chromosome sets of both parent cells, showed a greatly reduced take incidence. Initially these clones produced very few tumours, but the take incidence rose as continued cultivation of the cells in vitro resulted in progressive loss of chromosomes. In the case of the carcinoma/fibroblast hybrids, clonal populations with very high chromosome numbers were selected for special study. These were also found to have a very low take incidence, comparable to that of the hybrids formed by the fusion of the tumour cells with L cell derivatives. None of the tumours produced by the injection of either the sarcoma/fibroblast or carcinoma/fibroblast hybrids were composed of cells containing chromosome complements corresponding to the sum of the 2 parental chromosome sets; all the tumours were formed by selective overgrowth of cells from which some chromosomes had been eliminated. These results indicate that the malignancy of the tumour cells can be suppressed by diploid fibroblasts as well as by the L cell derivatives, but that the rapid chromosome losses characteristic of hybrids between these tumour cells and diploid fibroblasts generate malignant segregants with much greater frequency. In the range of material examined in the present experiments malignancy thus behaves as if it were a recessive character.

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 Epigenetics changes caused by the fusion of human embryonic stem cell and ovarian cancer cells

2016 ◽  
Vol 36 (5) ◽  
Author(s):  
Ke He ◽  
Hu Qu ◽  
Li-Nan Xu ◽  
Jun Gao ◽  
Fu-Yi Cheng ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Stem Cells ◽  
Cancer Cells ◽  
Human Embryonic Stem Cells ◽  
Embryonic Stem ◽  
Tumour Cells ◽  
Ovarian Cancer Cells ◽  
Hybrid Cells

To observe the effect of gene expression and tumorigenicity in hybrid cells of human embryonic stem cells (hESCs) and ovarian cancer cells in vitro and in vivo using a mouse model, and to determine its feasibility in reprogramming tumour cells growth and apoptosis, for a potential exploration of the role of hESCs and tumour cells fusion in the management of ovarian cancer. Stable transgenic hESCs (H1) and ovarian cancer cell line OVCAR-3 were established before fusion, and cell fusion system was established to analyse the related indicators. PTEN expression in HO-H1 cells was higher than those in the parental stem cells and lower than those in parental tumour cells; the growth of OV-H1 (RFP+GFP) hybrid cells with double fluorescence expressions were obviously slower than that of human embryonic stem cells and OVCAR-3 ovarian cancer cells. The apoptosis signal of the OV-H1 hybrid cells was significantly higher than that of the hESCs and OVCAR-3 ovarian cancer cells. In vivo results showed that compared with 7 days, 28 days and 35 days after inoculation of OV-H1 hybrid cells; also, apoptotic cell detection indicated that much stronger apoptotic signal was found in OV-H1 hybrid cells inoculated mouse. The hESCs can inhibit the growth of OVCAR-3 cells in vitro by suppressing p53 and PTEN expression to suppress the growth of tumour that may be achieved by inducing apoptosis of OVCAR-3 cells. The change of epigenetics after fusion of ovarian cancer cells and hESCs may become a novel direction for treatment of ovarian cancer.

The Analysis of Malignancy by Cell Fusion

1973 ◽  
Vol 12 (1) ◽  
pp. 253-261
Author(s):  
F. WIENER ◽  
G. KLEIN ◽  
H. HARRIS
Keyword(s):  
Tumour Cell ◽  
Tumour Cells ◽  
Hybrid Cells ◽  
Wild Type ◽  
Malignant Phenotype ◽  
L Cell ◽  
Progressive Growth ◽  
Mouse Tumour ◽  
Derivatives Of

Previous experiments showed that when a range of different highly malignant mouse tumour cells were fused with L cell derivatives of low tumorigenicity, the resulting hybrid cells, so long as they retained something close to the complete chromosome sets of both parent cells, had little or no ability to grow progressively in vivo. Tumours arising from the injection of such hybrids were produced not by progressive growth of the cells injected, but by selective overgrowth of cells from which certain specific, but as yet unidentified, chromosomes had been eliminated. In the present experiments the same malignant mouse tumour cells were fused with a highly malignant L cell derivative selected from the wild type cell population by passage through the animal. In all cases the resulting hybrid cells were found to be highly malignant; and the chromosome constitutions of the tumours arising from the injection of these hybrids were not significantly different from those of the cells injected. These findings confirm the interpretation given to the previous work; the L cell derivatives of low tumorigenicity contribute to the hybrid cells some factor, linked to specific chromosomes, that suppresses the malignant character of the tumour cell, and this suppression is removed, with consequent reappearance of the malignant phenotype, when certain chromosomes are eliminated.

The suppression of malignancy by terminal differentiation: evidence from hybrids between tumour cells and keratinocytes

1987 ◽  
Vol 87 (3) ◽  
pp. 383-388
Author(s):  
H. Harris ◽  
M.E. Bramwell
Keyword(s):  
Terminal Differentiation ◽  
Human Keratinocytes ◽  
Tumour Cells ◽  
Human Cells ◽  
Hybrid Cells ◽  
Progressive Growth ◽  
Cultivation In Vitro

When malignant human cells are crossed with diploid human keratinocytes, malignancy, as defined by progressive growth in vivo, is suppressed so long as the hybrid cells continue to produce involucrin, a protein that characterizes terminal differentiation in the keratinocyte. When, on continued cultivation in vitro, the cells lose the ability to produce involucrin, they reacquire the ability to grow progressively in the animal.

Effects of Heparin Oligosaccharides with High Affinity for Antithrombin III in Experimental Venous Thrombosis

1982 ◽  
Vol 47 (03) ◽  
pp. 244-248 ◽  
Author(s):  
D P Thomas ◽  
Rosemary E Merton ◽  
T W Barrowcliffe ◽  
L Thunberg ◽  
U Lindahl
Keyword(s):  
Antithrombin Iii ◽  
Specific Activity ◽  
High Specific Activity ◽  
Factor Xa ◽  
Blood Levels ◽  
Thrombin Time ◽  
High Affinity ◽  
Very High

SummaryThe in vitro and in vivo characteristics of two oligosaccharide heparin fragments have been compared to those of unfractionated mucosal heparin. A decasaccharide fragment had essentially no activity by APTT or calcium thrombin time assays in vitro, but possessed very high specific activity by anti-Factor Xa assays. When injected into rabbits at doses of up to 80 ¼g/kg, this fragment was relatively ineffective in impairing stasis thrombosis despite producing high blood levels by anti-Xa assays. A 16-18 monosaccharide fragment had even higher specific activity (almost 2000 iu/mg) by chromogenic substrate anti-Xa assay, with minimal activity by APTT. When injected in vivo, this fragment gave low blood levels by APTT, very high anti-Xa levels, and was more effective in preventing thrombosis than the decasaccharide fragment. However, in comparison with unfractionated heparin, the 16-18 monosaccharide fragment was only partially effective in preventing thrombosis, despite producing much higher blood levels by anti-Xa assays.It is concluded that the high-affinity binding of a heparin fragment to antithrombin III does not by itself impair venous thrombogenesis, and that the anti-Factor Xa activity of heparin is only a partial expression of its therapeutic potential.

scholarly journals Expression and Characterization of the Flocculin Flo11/Muc1, a Saccharomyces cerevisiae Mannoprotein with Homotypic Properties of Adhesion

2007 ◽  
Vol 6 (12) ◽  
pp. 2214-2221 ◽  
Author(s):  
Lois M. Douglas ◽  
Li Li ◽  
Yang Yang ◽  
A. M. Dranginis
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Biofilm Formation ◽  
In Vitro System ◽  
Glycosylphosphatidylinositol Anchor ◽  
Fungal Adhesion ◽  
Very High ◽  
Molecular Weight Form

ABSTRACT The Flo11/Muc1 flocculin has diverse phenotypic effects. Saccharomyces cerevisiae cells of strain background Σ1278b require Flo11p to form pseudohyphae, invade agar, adhere to plastic, and develop biofilms, but they do not flocculate. We show that S. cerevisiae var. diastaticus strains, on the other hand, exhibit Flo11-dependent flocculation and biofilm formation but do not invade agar or form pseudohyphae. In order to study the nature of the Flo11p proteins produced by these two types of strains, we examined secreted Flo11p, encoded by a plasmid-borne gene, in which the glycosylphosphatidylinositol anchor sequences had been replaced by a histidine tag. A protein of approximately 196 kDa was secreted from both strains, which upon purification and concentration, aggregated into a form with a very high molecular mass. When secreted Flo11p was covalently attached to microscopic beads, it conferred the ability to specifically bind to S. cerevisiae var. diastaticus cells, which flocculate, but not to Σ1278b cells, which do not flocculate. This was true for the 196-kDa form as well as the high-molecular-weight form of Flo11p, regardless of the strain source. The coated beads bound to S. cerevisiae var. diastaticus cells expressing FLO11 and failed to bind to cells with a deletion of FLO11, demonstrating a homotypic adhesive mechanism. Flo11p was shown to be a mannoprotein. Bead-to-cell adhesion was inhibited by mannose, which also inhibits Flo11-dependent flocculation in vivo, further suggesting that this in vitro system is a useful model for the study of fungal adhesion.

Mode of action of amphotericin B on chick embryo fibroblasts and on mouse Ehrlich tumour cells: a cytological and cytochemical analysis

1975 ◽  
Vol 18 (3) ◽  
pp. 441-451
Author(s):  
F. De Paermentier ◽  
R. Bassleer ◽  
A. Lepoint ◽  
C. Desaive ◽  
G. Goessens ◽  
...  
Keyword(s):  
Chick Embryo ◽  
Amphotericin B ◽  
Tumour Cells ◽  
Total Protein Content ◽  
Cell Multiplication ◽  
Cytochemical Analysis ◽  
Ehrlich Ascites ◽  
Embryo Fibroblasts

Chick embryo fibroblasts cultivated in vitro and Ehrlich ascites tumor cells (in vivo or in vitro) have been treated with amphotericin B. Cell multiplication is strongly inhibited. Large clear zones appear in the fibroblast nucleoi (phase-contrast and electron-microscope observations). Many treated fibroblasts and tumour cells have a high DNA content (pre-mitotic or polyploid level; measurements by cytophotometry). However, the RNA content (cytophotometry) and the total protein content (cytophotometry and micro-interferometry) are relatively low in the tumour cells. As shown by autoradiography, DNA synthesis is active but RNA synthesis and, in some cases, protein synthesis are inhibited. Due to this unbalanced growth, the cells cannot divide.

The extracellular matrix of hybrids between melanoma cells and normal fibroblasts

1988 ◽  
Vol 91 (2) ◽  
pp. 281-286
Author(s):  
M.C. Copeman ◽  
H. Harris
Keyword(s):  
Extracellular Matrix ◽  
Protease Activity ◽  
Malignant Tumour ◽  
Melanoma Cells ◽  
Chromosome Loss ◽  
Type I ◽  
Chromosome 4 ◽  
Hybrid Cells

It has been shown that when malignant tumour cells are fused with normal fibroblasts the suppression of malignancy in the hybrids is linked to their ability to produce a collagenous extracellular matrix in vivo. When, as a consequence of chromosome loss, segregants arise that reacquire malignancy, these do not produce any detectable matrix. In this paper we examine the main components of the extracellular matrix produced in vitro by hybrids between malignant mouse melanoma cells and normal mouse fibroblasts. Hybrids in which malignancy is suppressed synthesize about ten times as much type 1 procollagen as the malignant segregants derived from them; they also retain more fibronectin in the cell layer and release less protease activity into the medium. Malignant segregants more closely resemble the parental melanoma cells in producing fibronectin and mainly types IV and V procollagen. When hybrid cells in which malignancy is initially suppressed are grown continuously in vitro, the production of type I procollagen declines, and the production of type V procollagen and the release of protease activity into the medium increase. These changes, which are associated with the loss from the hybrid cells of both copies of the chromosome 4 derived from the parental fibroblast, predict the reacquisition of malignancy when the cells are inoculated into mice. It is possible that one gene or set of genes located on chromosome 4 determines both the execution of the fibroblast differentiation programme and the suppression of malignancy.

scholarly journals MicroRNA-1205 Regulation of FRYL in Prostate Cancer

2021 ◽  
Vol 9 ◽  
Author(s):  
Michelle Naidoo ◽  
Fayola Levine ◽  
Tamara Gillot ◽  
Akintunde T. Orunmuyi ◽  
E. Oluwabunmi Olapade-Olaopa ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Neuroendocrine Differentiation ◽  
Castration Resistant Prostate Cancer ◽  
Chromosomal Locus ◽  
Protein Coding ◽  
Castration Resistant ◽  
Dendritic Branching ◽  
Very High

High mortality rates of prostate cancer (PCa) are associated with metastatic castration-resistant prostate cancer (CRPC) due to the maintenance of androgen receptor (AR) signaling despite androgen deprivation therapies (ADTs). The 8q24 chromosomal locus is a region of very high PCa susceptibility that carries genetic variants associated with high risk of PCa incidence. This region also carries frequent amplifications of the PVT1 gene, a non-protein coding gene that encodes a cluster of microRNAs including, microRNA-1205 (miR-1205), which are largely understudied. Herein, we demonstrate that miR-1205 is underexpressed in PCa cells and tissues and suppresses CRPC tumors in vivo. To characterize the molecular pathway, we identified and validated fry-like (FRYL) as a direct molecular target of miR-1205 and observed its overexpression in PCa cells and tissues. FRYL is predicted to regulate dendritic branching, which led to the investigation of FRYL in neuroendocrine PCa (NEPC). Resistance toward ADT leads to the progression of treatment related NEPC often characterized by PCa neuroendocrine differentiation (NED), however, this mechanism is poorly understood. Underexpression of miR-1205 is observed when NED is induced in vitro and inhibition of miR-1205 leads to increased expression of NED markers. However, while FRYL is overexpressed during NED, FRYL knockdown did not reduce NED, therefore revealing that miR-1205 induces NED independently of FRYL.

The Analysis of Malignancy by Cell Fusion

1971 ◽  
Vol 8 (3) ◽  
pp. 673-680
Author(s):  
U. BREGULA ◽  
G. KLEIN ◽  
H. HARRIS
Keyword(s):  
Cell Fusion ◽  
Chromosomal Analysis ◽  
Cell Populations ◽  
Hybrid Cells ◽  
Parental Chromosome ◽  
Chromosomal Constitution ◽  
Diploid Fibroblasts ◽  
Ehrlich Ascites ◽  
Ehrlich Ascites Cells

When Ehrlich ascites cells were fused with diploid fibroblasts, isolated directly from the animal, the resulting hybrid cells regularly produced progressive tumours. However, an analysis of a range of clonal populations of these hybrid cells, each derived from a separate primary fusion, revealed that the chromosomal constitution of these cells was highly unstable; all cell populations were found to have already undergone substantial chromosome losses by the time enough cells were available to permit chromosomal analysis. Thus, although these hybrid cells were highly tumorigenic, the tumours arising from them were not composed of cells with complete parental chromosome sets, but of cells from which some chromosomes had been eliminated.

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