scholarly journals Dynamics of cell transformation in culture and its significance for tumor development in animals

2017 ◽  
Vol 114 (46) ◽  
pp. 12237-12242 ◽  
Author(s):  
Harry Rubin
Keyword(s):  
Cell Transformation ◽  
Calf Serum ◽  
Tumor Development ◽  
Basal Medium ◽  
Saturation Density ◽  
Neoplastic Progression ◽  
First Response ◽  
Ras Oncogenes ◽  
Nih 3T3 ◽  
Do So

NIH 3T3 cells grown in conventional Dulbecco’s modification of Eagle’s basal medium (DME) produce no transformed foci when grown to confluence in 10% calf serum (CS). A few cultures were transformed by ras oncogenes when transfected with DNA from neoplastic cells, but they failed to do so in 80 to 90% of the transfections. However, when they were grown in a medium [molecular, cellular, and developmental biology 402 (MCDB 402)] optimized for their clonal growth in minimal serum, they produced transformed foci without transfection in 10% CS, but not in 2% CS. The first response to growth in MCDB 402 in 2% CS in successive rounds of contact inhibition was uniform increases in saturation density of the population. This was followed by the appearance of transformed foci. A systematic study was made of the dynamics of neoplastic progression in various concentrations of CS in a single round of confluence at 2 and 3 wk, followed by three sequential rounds of confluence in 2% CS for 2 wk. There was a linear relationship between CS concentration and saturation density in the first-round cultures and continuing differences in subsequent cultures. The hyperplastic field of normal-looking cells surrounding transformed foci became increasingly permissive for transformation with serial culture. The dynamics show that epigenetic selection is the major driving force of neoplastic development. Cells from dense foci produced malignant fibrosarcomas in mice, thereby exhibiting a positive relationship between transformation in culture and the development of tumors.

Turbomolecular Pumped Electron Microscopy of Rubella Virus (In BHK Celis)

1968 ◽  
Vol 26 ◽  
pp. 204-205
Author(s):  
A. B. Taylor ◽  
G. C. Cole ◽  
M. A. Holcomb ◽  
C. A. Baechler
Keyword(s):  
Electron Microscopy ◽  
Rubella Virus ◽  
Phosphate Buffer ◽  
Fetal Calf Serum ◽  
Calf Serum ◽  
Basal Medium ◽  
Kidney Cells ◽  
Baby Hamster Kidney ◽  
Input Multiplicity ◽  
Baby Hamster Kidney Cells

An aliquot from a continuous fermenter culture of baby hamster kidney cells (BHK-21 Clone PD-4) (Wistar) maintained in Ca free Eagle's Basal Medium containing 2% Kaolin adsorbed fetal calf serum was planted in spinner flasks at 300,000 cells per ml, total volume 600 ml. After equilibration for one day at 35°C to insure that cells were in log phase, the culture was infected with the M-33-AGMK25 BHK-219 strain of rubella at an input multiplicity of about 6 TCID50 per cell. The virus was identified with specific rubella antiserum.Preliminary experiments had shown that such cultures would reach a peak or plateau HA titer of approximately 1:64, 24 hrs after inoculation and would continue to yield virus for 6 to 12 days. One hundred ml aliquot harvests were withdrawn daily and the culture was returned to volume with growth medium and incubation continued. The harvested cells were spun down rapidly at 2500 rpm per 15 mins., fixed in 3.7% gluteraldehyde in Ca free phosphate buffer saline, and post fixed in osmium tetraoxide. After dehydration, the cells were embedded in Epon 812 and cured approximately 20 hrs at 60°C.

An Inhibitor Present in Calf Serum Which Prevents Growth of BHK21 Cells in Suspension Culture

1972 ◽  
Vol 10 (1) ◽  
pp. 137-152
Author(s):  
H. OTSUKA
Keyword(s):  
Suspension Culture ◽  
Calf Serum ◽  
Soft Agar ◽  
Transformed Cells ◽  
Ammonium Sulphate Precipitation ◽  
Serum Inhibitor ◽  
Swine Serum ◽  
Rna And Dna Synthesis ◽  
Rna And Dna ◽  
Do So

BHK21 cells do not form colonies in soft agar suspension culture in the presence of calf serum; but if swine serum is used instead they do so. In methylcellulose suspension culture supplemented with calf serum the cells synthesize very little RNA or DNA, but if swine serum is used there is a marked increase of syntheses. Calf serum was found to contain an inhibitor which prevents the induction, but not the continuation, of RNA and DNA synthesis in BHK21 cells. In contrast the growth of polyoma-virus-transformed cells is not affected by this serum inhibitor which has been partially purified from calf serum by ammonium sulphate precipitation followed by Sephadex G-200 column chromatography.

scholarly journals Autophagy in Viral Development and Progression of Cancer

2021 ◽  
Vol 11 ◽  
Author(s):  
Alejandra Suares ◽  
María Victoria Medina ◽  
Omar Coso
Keyword(s):  
Cell Fate ◽  
Cell Transformation ◽  
Tumor Development ◽  
Lysosomal Hydrolases ◽  
Subsequent Degradation ◽  
Cellular Context ◽  
Tumor Transformation ◽  
Proliferation And Metastasis ◽  
Viral Development ◽  
Catabolic Process

Autophagy is a complex degradative process by which eukaryotic cells capture cytoplasmic components for subsequent degradation through lysosomal hydrolases. Although this catabolic process can be triggered by a great variety of stimuli, action in cells varies according to cellular context. Autophagy has been previously linked to disease development modulation, including cancer. Autophagy helps suppress cancer cell advancement in tumor transformation early stages, while promoting proliferation and metastasis in advanced settings. Oncoviruses are a particular type of virus that directly contribute to cell transformation and tumor development. Extensive molecular studies have revealed complex ways in which autophagy can suppress or improve oncovirus fitness while still regulating viral replication and determining host cell fate. This review includes recent advances in autophagic cellular function and emphasizes its antagonistic role in cancer cells.

Activation of c-myc and c-K-ras oncogenes in primary rat tumors induced by ionizing radiation

1987 ◽  
Vol 7 (2) ◽  
pp. 932-935
Author(s):  
M J Sawey ◽  
A T Hood ◽  
F J Burns ◽  
S J Garte
Keyword(s):  
Ionizing Radiation ◽  
Tissue Specificity ◽  
3T3 Cells ◽  
Rat Skin ◽  
Oncogene Activation ◽  
Myc Gene ◽  
Ras Oncogenes ◽  
Restriction Polymorphisms ◽  
Rat Tumors ◽  
Nih 3T3

An activated K-ras oncogene was detected by transfection in NIH 3T3 cells and by Southern blot analysis in 6 of 12 rat skin tumors induced by ionizing radiation. The DNA from 10 of the 12 tumors also showed c-myc gene amplification and restriction polymorphisms. Evidence for tissue specificity was observed in patterns of oncogene activation, with each of three clear cell carcinomas exhibiting activation of both c-myc and K-ras oncogenes.

Morphological Differentiation of Astroglial Progenitor Cells from Egf-Responsive Neurospheres in Response to Fetal Calf Serum, Basic Fibroblast Growth Factor, and Retinol

1996 ◽  
Vol 5 (2) ◽  
pp. 179-189 ◽  
Author(s):  
Yung H. Chiang ◽  
Vincenzo Silani ◽  
Feng C. Zhou
Keyword(s):  
Stem Cells ◽  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Progenitor Cells ◽  
Basic Fibroblast Growth Factor ◽  
Calf Serum ◽  
Basal Medium ◽  
Morphological Differentiation ◽  
Fibroblast Growth ◽  
Brain Areas

Procurement of multipotential neuroglial stem cells is possible with the addition of epidermal growth factor (EGF). Stem cells will differentiate into neurons and glia upon the removal of EGF from the culture medium. We have previously characterized the neuronal differentiation of stem cells derived from long-term cultured nonpassage neurospheres. In the current study, we (1) characterize the morphological differentiation of the astroglial progenitor cell from 3-mo-old neurospheres, (2) examine whether the astroglial progenitor cells from neurospheres of different brain areas exhibit different differentiation responses to the same exogenous signals, and (3) test the effects of basic fibroblast growth factor (bFGF) and retinol on differentiation. Cerebral cortex, striatum, and mesencephalon cells were obtained from Embryonic Day 14 (E-14) rat fetuses and were dissociated for the procurement of neurospheres in chemically defined medium supplemented with EGF. After 3 mo in culture, the neurospheres, derived from each of the three brain areas, were subcultured into three groups on chamber slides: (1) basal medium, (2) the basal medium plus 20 ng/mL bFGF, and (3) the basal medium plus 10 μM retinol. Phenotypic expression of astroglial cells was examined after 14 days subculture. Our findings indicate that the 3-mo-old cultured nonpassage neurospheres contained numerous multipotential stem cells that stained positive with nestin, and that environmental factors played an important role in influencing the differentiation of astroglial progenitor cells. As detected by glial fibrillary acid protein (GFAP), astroglial progenitor cells turned into protoplasmic astrocytes in the FCS-containing basal medium, fibrous astrocytes in the presence of bFGF, and spindle-shaped astrocytes in the presence of retinol. There were no noticeable differences in differentiation among astroglial progenitor cells of the various brain region-derived neurospheres in any of the three medium conditions. Peculiar varicosity-and growth cone-like structures on the long slender GFAP-positive processes suggest that neuroblasts and glioblast may share common morphologies, features, or common progenitor cells during initial differentiation in vitro.

scholarly journals HIC1 and RassF1A Methylation Attenuates Tubulin Expression and Cell Stiffness in Cancer

2018 ◽  
Vol 19 (10) ◽  
pp. 2884 ◽  
Author(s):  
Chih-Cheng Chen ◽  
Bo-Ching He ◽  
Yao-Li Chen ◽  
Kuan-Der Lee ◽  
Chun-Hsin Tung ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Cultured Cells ◽  
Cell Transformation ◽  
Tumor Development ◽  
Cellular Transformation ◽  
Cell Stiffness ◽  
Physiological Status ◽  
Rassf1a Methylation ◽  
Potential Biomarker

Cell stiffness is a potential biomarker for monitoring cellular transformation, metastasis, and drug resistance development. Environmental factors relayed into the cell may result in formation of inheritable markers (e.g., DNA methylation), which provide selectable advantages (e.g., tumor development-favoring changes in cell stiffness). We previously demonstrated that targeted methylation of two tumor suppressor genes, hypermethylated in cancer 1 (HIC1) and Ras-association domain family member 1A (RassF1A), transformed mesenchymal stem cells (MSCs). Here, transformation-associated cytoskeleton and cell stiffness changes were evaluated. Atomic force microscopy (AFM) was used to detect cell stiffness, and immunostaining was used to measure cytoskeleton expression and distribution in cultured cells as well as in vivo. HIC1 and RassF1A methylation (me_HR)-transformed MSCs developed into tumors that clonally expanded in vivo. In me_HR-transformed MSCs, cell stiffness was lost, tubulin expression decreased, and F-actin was disorganized; DNA methylation inhibitor treatment suppressed their tumor progression, but did not fully restore their F-actin organization and stiffness. Thus, me_HR-induced cell transformation was accompanied by the loss of cellular stiffness, suggesting that somatic epigenetic changes provide inheritable selection markers during tumor propagation, but inhibition of oncogenic aberrant DNA methylation cannot restore cellular stiffness fully. Therefore, cell stiffness is a candidate biomarker for cells’ physiological status.

scholarly journals Identification of a new common provirus integration site in gross passage A murine leukemia virus-induced mouse thymoma DNA.

1987 ◽  
Vol 7 (1) ◽  
pp. 512-522 ◽  
Author(s):  
R Villemur ◽  
Y Monczak ◽  
E Rassart ◽  
C Kozak ◽  
P Jolicoeur
Keyword(s):  
T Cell ◽  
Murine Leukemia Virus ◽  
Cell Transformation ◽  
Integration Site ◽  
Leukemia Virus ◽  
Tumor Development ◽  
Mouse Strains ◽  
Mouse Tumor ◽  
Provirus Integration ◽  
Murine Leukemia

The Gross passage A murine leukemia virus (MuLV) induced T-cell leukemia of clonal (or oligoclonal) origin in inoculated mice. To study the role of the integrated proviruses in these tumor cells, we cloned several newly integrated proviruses (with their flanking cellular sequences) from a single tumor in procaryotic vectors. With each of the five clones obtained, a probe was prepared from the cellular sequences flanking the provirus. With one such probe (SS8), we screened several Gross passage A MuLV-induced SIM.S mouse tumor DNAs and found that, in 11 of 40 tumors, a provirus was integrated into a common region designated Gin-1. A 26-kilobase-pair sequence of Gin-1 was cloned from two lambda libraries, and a restriction map was derived. All proviruses were integrated as a cluster in the same orientation within a 5-kilobase-pair region of Gin-1, and most of them had a recombinant structure of the mink cell focus-forming virus type. The frequency of Gin-1 occupancy by provirus was much lower in thymoma induced by other strains of MuLV in other mouse strains. Using somatic-cell hybrid DNAs, we mapped Gin-1 on mouse chromosome 19. Gin-1 was not homologous to 16 known oncogenes and was distinct from the other common regions for provirus integration previously described. Therefore, Gin-1 appears to represent a new common provirus integration region. The integration of a provirus within Gin-1 might be an important event leading to T-cell transformation, and the Gin-1 region might harbor sequences which are involved in tumor development.

KSHV-GPCR and CXCR2 Transforming Capacity and Angiogenic Responses Are Mediated through a JAK2-STAT3 Dependent Pathway.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4347-4347
Author(s):  
Meike Burger ◽  
Tanja Hartmann ◽  
Jan A. Burger ◽  
Ingrid U. Schraufstatter
Keyword(s):  
Kaposi's Sarcoma ◽  
Cell Transformation ◽  
Kaposi’S Sarcoma ◽  
Fiber Formation ◽  
Actin Stress Fiber ◽  
3T3 Cells ◽  
Focus Formation ◽  
Nih 3T3 ◽  
Dependent Pathway ◽  
Nih 3T3 Cells

Abstract The Kaposi’s sarcoma herpesvirus encodes a G-protein-coupled chemokine receptor termed KSHV-GPCR. Expression of this constitutively active GPCR leads to cell transformation and vascular overgrowth characteristic of Kaposi’s sarcoma. Previously, we have shown that CXCR2, the closest human homologue, is similarly able to transform cells if continously stimulated or constitutively activated by amino acid exchange D138V of the DRY sequence. Here, we demonstrate that STAT3 activation is a prerequisite for transformation in KSHV-GPCR and CXCR2 transfected NIH 3T3 cells. In KSHV-GPCR and D138V transfected cells, STAT-3 is constitutively phosphorylated on Tyr705. In CXCR2 transfected NIH 3T3 cells and human microvascular endothelial cells (HMEC), which express the CXCR2 constitutively, STAT3 is phosphorylated upon stimulation with IL-8 (CXCL8). Focus formation in NIH 3T3 cells transfected with the KSHV-GPCR, CXCR2, or the D138V mutant, was blocked by the specific JAK2 inhibitor AG490. Typical functions of the CXCR2 including actin stress fiber formation, haptotaxis, and the angiogenic response in HMEC shown by tube formation in Matrigel were blocked by AG490. These data suggest that the transforming capacity and migratory responses that are involved in tumor development, metastasis and angiogenesis in KSHV or CXCR2-expressing cells is at least partially mediated through a JAK2-STAT3 dependent pathway.

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