scholarly journals Intracellular ionic changes in normal and transformed human fibroblasts after extracellular Ca2+ deprivation

1981 ◽  
Vol 194 (3) ◽  
pp. 707-711 ◽  
Author(s):  
B J Hazelton ◽  
J T Tupper
Keyword(s):  
Growth Response ◽  
Human Fibroblasts ◽  
Growth Arrest ◽  
Fold Increase ◽  
Transformed Cells ◽  
Transformed Cell ◽  
Permeability Changes ◽  
Na Efflux ◽  
Ionic Changes ◽  
G0 Phase

The lowering of extracellular Ca2+ concentration in the growth medium reversibly blocks normal, but not SV40-transformed WI38 diploid fibroblasts in the early G1/G0 phase of the cell cycle. This growth response is characterized by specific changes in ionic content and transport. Ca2+ deprivation (0.03 mM) has little effect on the K+ content of either normal or transformed cells. Na+ content, however, is increased nearly 2-fold in the normal cells. This increase is presumably due to a 3-fold increase in unidirectional Na+ influx in Ca2+-deprived cells. The increased intracellular Na+ also gives rise to a nearly 3-fold enhancement of the active (ouabain-sensitive) Na+ efflux. Ca2+ deprivation causes only slight increases in Na+ influx, ouabain-sensitive Na+ efflux and intracellular Na+ in the transformed cell. In contrast, the transformed cells lose nearly 60% of their intracellular Ca2+ on deprivation, whereas normal WI38 cells lose only 10%. The data suggest that the growth arrest exhibited by the normal cell but not the transformed cell may be related to different membrane-transport and permeability changes in response to Ca2+ deprivation.

scholarly journals Fibronectin expression is determined by the genotype of the transformed parental cells in heterokaryons between normal and transformed fibroblasts.

1979 ◽  
Vol 80 (1) ◽  
pp. 118-127 ◽  
Author(s):  
P Laurila ◽  
J Wartiovaara ◽  
S Stenman
Keyword(s):  
Cell Surface ◽  
Minimal Surface ◽  
Human Fibroblasts ◽  
Transformed Cells ◽  
Transformed Cell ◽  
Gene Dose ◽  
Fibronectin Expression ◽  
A Cell ◽  
Dose Dependent ◽  
Was Gene

The expression of fibronectin, a cell surface-associated transformation-sensitive glycoprotein, was studied in hetero- and homokaryons of normal and SV40-transformed human fibroblasts. In immunofluorescence, fibroblast homokaryons had an intense surface-associated and intracelluar fibronectin fluorescence similar to that of normal fibroblasts. Transformed cells and their homokaryons had a minimal surface-associated and a weak intracellular fibronectin fluorescence. In heterokaryons formed between transformed and normal fibroblasts, the expression of fibronectin fell within 24 h to the level of the transformed cell homokaryons. The change was detectable already at 3 h after fusion and was gene-dose dependent. These results show that the transformed genotype determines fibronectin expression in the heterokaryons.

GROWTH DEPENDENT 2-DEOXY-D-GLUCOSE UPTAKE IN TRANSFORMED AND NORMAL MOUSE CELLS

1974 ◽  
Vol 16 (4) ◽  
pp. 823-830 ◽  
Author(s):  
Patricia A. Martin-De Leon ◽  
Barid B. Mukherjee
Keyword(s):  
Fold Increase ◽  
Lung Fibroblasts ◽  
Transformed Cells ◽  
Embryonic Cells ◽  
Transformed Cell ◽  
Serum Stimulation ◽  
Dependent Inhibition ◽  
Sarcoma Virus ◽  
Cell Densities ◽  
Transformed Cell Lines

The rates of uptake of 2-deoxyglucose were studied in a) 15-day BALB/c and AKR embryonic cells, b) adult BALB/c lung fibroblasts and c) virally-transformed cell lines derived from a clone of BALB/c cells. At high cell densities in confluent cultures of non-transformed cells the rates of uptake were three to seven times lower than those in transformed cells at the equivalent densities. Both non-transformed and virally-transformed cell cultures showed density-dependent inhibition of 2-deoxyglucose uptake. However, inhibition was only slight in SV40 (SVT2) and Kirsten sarcoma virus-transformed (K-A31) cells in which uptake rates decreased 2.3– and 2.5– fold respectively during a 12-fold increase in cell densities. For an almost similar increase in cell density, in unestablished adult embryonic BALB/c fibroblasts, the rate of uptake decreased 8-fold. Incorporation of H3-thymidine (an indication of growth rate) occurred at a higher rate in transformed than in contact-inhibited cells. Two hours after serum stimulation of contact-inhibited AKR cells there was approximately 50% increase in the rate of 2-deoxyglucose uptake. The results confirm previous findings that the increased uptake of 2-deoxyglucose by virally-transformed cells may be due to their growth and division and not necessarily to the direct expression of the viral genome.

scholarly journals Design, Synthesis, and Cytotoxicity Assessment of [64Cu]Cu-NOTA-Terpyridine Platinum Conjugate: A Novel Chemoradiotherapeutic Agent with Flexible Linker

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2154
Author(s):  
Meysam Khosravifarsani ◽  
Samia Ait-Mohand ◽  
Benoit Paquette ◽  
Léon Sanche ◽  
Brigitte Guérin
Keyword(s):  
Colorectal Cancer ◽  
Cancer Cells ◽  
Human Fibroblasts ◽  
Fold Increase ◽  
Radiation Energy ◽  
Design Synthesis ◽  
Quadruplex Dna ◽  
Low Energy Electrons ◽  
Normal Human

Maximum benefits of chemoradiation therapy with platinum-based compounds are expected if the radiation and the drug are localized simultaneously in cancer cells. To optimize this concomitant effect, we developed the novel chemoradiotherapeutic agent [64Cu]Cu-NOTA-C3-TP by conjugating, via a short flexible alkyl chain spacer (C3), a terpyridine platinum (TP) moiety to a NOTA chelator complexed with copper-64 (64Cu). The decay of 64Cu produces numerous low-energy electrons, enabling the 64Cu-conjugate to deliver radiation energy close to TP, which intercalates into G-quadruplex DNA. Accordingly, the in vitro internalization kinetic and the cytotoxic activity of [64Cu]Cu-NOTA-C3-TP and its derivatives were investigated with colorectal cancer (HCT116) and normal human fibroblast (GM05757) cells. Radiolabeling by 64Cu results in a >55,000-fold increase of cytotoxic potential relative to [NatCu]Cu-NOTA-C3-TP at 72 h post administration, indicating a large additive effect between 64Cu and the TP drug. The internalization and nucleus accumulation of [64Cu]Cu-NOTA-C3-TP in the HCT116 cells were, respectively, 3.1 and 6.0 times higher than that for GM05757 normal human fibroblasts, which is supportive of the higher efficiency of the [64Cu]Cu-NOTA-C3-TP for HCT116 cancer cells. This work presents the first proof-of-concept study showing the potential use of the [64Cu]Cu-NOTA-C3-TP conjugate as a targeted chemoradiotherapeutic agent to treat colorectal cancer.

Genomic and metabolomic analysis of step-wise malignant transformation in human skin fibroblasts

2019 ◽  
Vol 41 (5) ◽  
pp. 656-665
Author(s):  
Anastasia Kariagina ◽  
Sophia Y Lunt ◽  
J Justin McCormick
Keyword(s):  
Malignant Transformation ◽  
Human Fibroblasts ◽  
Glucose Consumption ◽  
Tca Cycle ◽  
Transformed Cells ◽  
Aminooxyacetic Acid ◽  
Malignant Cells ◽  
The Impact

Abstract Metabolic changes accompanying a step-wise malignant transformation was investigated using a syngeneic lineage of human fibroblasts. Cell immortalization was associated with minor alterations in metabolism. Consecutive loss of cell cycle inhibition in immortalized cells resulted in increased levels of oxidative phosphorylation (OXPHOS). Overexpression of the H-Ras oncoprotein produced cells forming sarcomas in athymic mice. These transformed cells exhibited increased glucose consumption, glycolysis and a further increase in OXPHOS. Because of the markedly increased OXPHOS in transformed cells, the impact of a transaminase inhibitor, aminooxyacetic acid (AOA), which decreases glutamine influx to the tricarboxylic acid (TCA) cycle, was tested. Indeed, AOA significantly decreased proliferation of malignantly transformed fibroblasts and fibrosarcoma-derived cells in vitro and in vivo. AOA also decreased proliferation of cells susceptible to malignant transformation. Metabolomic studies in normal and transformed cells indicated that, in addition to the anticipated effect on the TCA cycle, AOA decreased production of nucleotides adenosine triphosphate (ATP) and uridine monophosphate. Exogenous nucleotides partially rescued decreased proliferation of the malignant cells treated with AOA. Our data indicate that AOA blocks several metabolic pathways essential for growth of malignant cells. Therefore, OXPHOS may provide important therapeutic targets for treatment of sarcoma.

scholarly journals Hyaluronate synthetase inhibition by normal and transformed human fibroblasts during growth reduction

1987 ◽  
Vol 104 (4) ◽  
pp. 1105-1115 ◽  
Author(s):  
K Matuoka ◽  
M Namba ◽  
Y Mitsui
Keyword(s):  
Cell Proliferation ◽  
Cell Density ◽  
Human Fibroblasts ◽  
Transformed Cells ◽  
Synthetase Activity ◽  
Intact Cells ◽  
Free System ◽  
Glycosaminoglycan Synthesis ◽  
Cell Free System ◽  
A Cell

To establish the relation of glycosaminoglycan synthesis to cell proliferation, we investigated the synthesis of individual glycosaminoglycan species by intact cells and in a cell-free system, using normal and transformed human fibroblasts under differing culture conditions. Reducing serum concentration brought about a marked decline in the synthesis of hyaluronate (HA) as well as cell proliferation on both normal and transformed cells. Both HA synthesis and proliferation decreased with increasing cell densities markedly (in inverse proportion to cell density) in normal cells but gradually in transformed cells. This noticeable congruity of the changes in HA synthesis and proliferation indicates that the change in HA synthesis is related primarily to cell proliferation rather than to cell density or cellular transformation. Examination of HA synthesis in a cell-free system demonstrated that the activity of HA synthetase also fluctuated in conjunction with cell proliferation. Furthermore, growth-reduced cells (except crowded transformed cells) inhibited cell-free HA synthesis and this inhibition was induced coincidentally with a decrease in both HA synthetase activity and proliferation. These findings suggest that the change in HA synthesis is significant in the regulation of cell proliferation.

scholarly journals Human Papillomavirus E6 Proteins Mediate Resistance to Interferon-Induced Growth Arrest through Inhibition of p53 Acetylation

2007 ◽  
Vol 81 (23) ◽  
pp. 12740-12747 ◽  
Author(s):  
Christy Hebner ◽  
Melanie Beglin ◽  
Laimonis A. Laimins
Keyword(s):  
Human Papillomavirus ◽  
Human Fibroblasts ◽  
Antiviral Agents ◽  
Growth Arrest ◽  
Physiological Role ◽  
Human Keratinocytes ◽  
Hpv E6 ◽  
E6 And E7 ◽  
E7 Proteins ◽  
Mutant Forms

ABSTRACT The high-risk human papillomavirus (HPV) E6 and E7 proteins act cooperatively to mediate multiple activities in viral pathogenesis. For instance, E7 acts to increase p53 levels while E6 accelerates its rate of turnover through the binding of the cellular ubiquitin ligase E6AP. Interferons are important antiviral agents that modulate both the initial and persistent phases of viral infection. The expression of HPV type 16 E7 was found to sensitize keratinocytes to the growth-inhibitory effects of interferon, while coexpression of E6 abrogates this inhibition. Treatment of E7-expressing cells with interferon ultimately resulted in cellular senescence through a process that is dependent upon acetylation of p53 by p300/CBP at lysine 382. Cells expressing mutant forms of E6 that are unable to bind p300/CBP or bind p53 failed to block acetylation of p53 at lysine 382 and were sensitive to growth arrest by interferon. In contrast, mutant forms of E6 that are unable to bind E6AP remain resistant to the effects of interferon, demonstrating that the absolute levels of p53 are not the major determinants of this activity. Finally, p53 acetylation at lysine 382 was found not to be an essential determinant of other types of senescence such as that induced by overexpression of Ras in human fibroblasts. This study identifies an important physiological role for E6 binding to p300/CBP in blocking growth arrest of human keratinocytes in the presence of interferon and so contributes to the persistence of HPV-infected cells.

scholarly journals Isolation of cellular genes differentially expressed in mouse NIH 3T3 cells and a simian virus 40-transformed derivative: growth-specific expression of VL30 genes.

1985 ◽  
Vol 5 (10) ◽  
pp. 2590-2598 ◽  
Author(s):  
K Singh ◽  
S Saragosti ◽  
M Botchan
Keyword(s):  
Cell Lines ◽  
Simian Virus 40 ◽  
Mouse Cell ◽  
Simian Virus ◽  
Differentially Expressed ◽  
Transformed Cells ◽  
3T3 Cells ◽  
Transformed Cell ◽  
Nih 3T3 ◽  
Nih 3T3 Cells

We constructed and screened a cDNA library made from simian virus 40 (SV40)-transformed NIH 3T3 cells, and we isolated cDNAs representing genes that are differentially expressed between the parental cell and its SV40-transformed derivative. We found only a small number of cDNAs representing such genes. Two isolated cDNA clones represented RNAs expressed at elevated levels in the transformed cell line in a manner relatively independent of growth conditions. The expression of two other cDNAs was growth specific because transformed cells and nonconfluent parental cells contained higher levels of the homologous RNAs than did confluent, contact-inhibited parental cells. Another cDNA was well expressed in confluent parental and confluent transformed cells, but not in nonconfluent cells. The expression of some of these cDNAs varied strikingly in different mouse cell lines. Thus the genotype or histories of different cell lines can also affect the expression of certain genes. Interestingly, the only cDNA isolated that was expressed exclusively in the transformed cell was from an SV40 message. We focused on a growth-specific cDNA which we show is derived from a mouse endogenous retrovirus-like family called VL30. We sequenced the 3' long terminal repeat (LTR) of this transcriptionally active VL30 gene. This LTR has good homology with other VL30 LTR sequences, but differences occur, particularly upstream of the VL30 promoter. We found that VL30 gene expression varied in different mouse cell lines such that C3H cell lines had very low levels of VL30 transcripts relative to NIH 3T3 cell lines. However, Southern analysis showed that both cell lines had about the same number of VL30 genes homologous to our probe and that the position of the majority of these genes was conserved. We discuss possible explanations for this difference in VL30 expression.

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