Efficient reversion of simian sarcoma virus-transformation and inhibition of growth factor-induced mitogenesis by suramin.

Betsholtz, Christer; Johnsson, Ann; Heldin, Carl Henrik; Westermark, Bengt

doi:10.1073/pnas.83.17.6440

Cited by 232 publications

(113 citation statements)

References 30 publications

Supporting

Mentioning

104

Contrasting

Order By: Relevance

“…Ras-transformed V12H10 and K61N10 cells were therefore assayed for their ability to proliferate in the absence of serum for 48 h. The expression of either activated Ha-ras or N-ras resulted in serum-independent growth, with cells proliferating at a rate slightly lower than that observed in the presence of 10% FCS (data not shown). In order to assess the impact of a potential autocrine growth factor mechanism mediating Ras-dependent, serum-independent proliferation, cells were incubated in serum-free DMEM in the presence of increasing concentrations of the growth factor antagonist, suramin (Betsholtz et al, 1986;Kehinde et al, 1995). Suramin blocks the interaction between growth factors and their cognate receptors and its e ects are readily reversible.…”

Section: Expression Of Activated Ras In C3h10t1/2 ®Broblastsmentioning

confidence: 99%

Ha-ras and N-ras regulate MAPK activity by distinct mechanisms in vivo

Hamilton

Wolfman

1998

Oncogene

View full text Add to dashboard Cite

The Ras GTPases function as molecular switches, regulating a multiplicity of biological events. However the contribution, if any, of a speci®c c-Ras isoform (Ha-, N-, or Ki-ras A or B) in the regulation of a given biological or biochemical process, is unknown. Murine C3H10T1/2 ®broblasts transformed with activated (G12V)Ha-ras or (Q61K)N-ras proliferate in serum-free media and have constitutive MAPK activity. The growth factor antagonist, suramin, inhibited the serum-independent proliferation of Ha-ras transformed ®broblasts, but not the serum-independent proliferation of N-ras transformed cells. The inhibition of cell proliferation was concomitant with the abrogation of the constitutive MAPK activity in the Ha-ras transformed ®broblasts. Analysis of the Ras-signalling complexes in immunoprecipitates from Ha-ras transformed cells revealed that Raf-1 co-immunoprecipitated with endogenous c-N-ras but not (G12V)Ha-ras. Pretreatment with suramin resulted in the loss of Raf-1 from c-N-ras immunoprecipitates. A c-N-ras antisense oligonucleotide, which down-regulated c-N-ras protein levels, abrogated the constitutive MAPK activity and serum-independent proliferation of (G12V)Ha-ras transformed cells. The data suggest that Raf-1 has a higher a nity for N-ras then Ha-ras in vivo, and c-N-ras function is required for the serum-independent proliferation of Ha-ras transformed cells.

show abstract

Section: Expression Of Activated Ras In C3h10t1/2 ®Broblastsmentioning

confidence: 99%

Ha-ras and N-ras regulate MAPK activity by distinct mechanisms in vivo

Hamilton

Wolfman

1998

Oncogene

View full text Add to dashboard Cite

show abstract

“…The data is representative of two independent experiments. cated that the serum-independent proliferation of V12H10 cells was sensitive to the actions of suramin (15), a nonspecific growth factor antagonist (13,14). This observation implied that the serum-independent proliferation of V12H10 cells was regulated by an autocrine growth factor(s).…”

Section: Fig 2 a Egfr Inhibitors Block Mapk Activation By V12h10:cmmentioning

confidence: 99%

“…We recently reported that mouse fibroblasts transformed by the minimal expression of activated (G12V)Ha-Ras (V12H10 cells) were unable to proliferate in serum-free medium in the presence of suramin, a growth factor antagonist (13)(14)(15). The constitutive MAPK activity in these cells was completely abrogated by the addition of suramin.…”

mentioning

confidence: 99%

Oncogenic Ha-Ras-dependent Mitogen-activated Protein Kinase Activity Requires Signaling Through the Epidermal Growth Factor Receptor

Hamilton

Wolfman

1998

Journal of Biological Chemistry

View full text Add to dashboard Cite

C3H10T1/2 fibroblasts transformed by the minimal expression of oncogenic Ha-Ras (V12H10 cells) or N-Ras (K61N10 cells) have constitutive mitogen-activated protein kinase (MAPK) activity and proliferate in serumfree medium. The constitutive MAPK activity and serum-independent proliferation of V12H10 cells are sensitive to the growth factor antagonist, suramin (Hamilton, M., and Wolfman, A. (1998) Oncogene 16, 1417-1428), suggesting that Ha-Ras-mediated regulation of the MAPK cascade is dependent upon the action of an autocrine factor. Serum-free medium conditioned by V12H10 cells contains an activity that stimulates MAPK activity in quiescent fibroblasts. This MAPK stimulatory activity could be specifically blocked by the epidermal growth factor receptor (EGFR) inhibitors, PD153035 and PD158780. These inhibitors also blocked the serumindependent proliferation of V12H10 cells. Immunodepletion of conditioned medium with antibodies to transforming growth factor ␣ and EGF significantly inhibited its ability to stimulate MAPK activity. Stable transfection of EGFR-negative NR6 and EGFR-positive Swiss3T3 cells with oncogenic (G12V)Ha-Ras demonstrated that only the Ha-Ras-transfected Swiss 3T3 cells possessed constitutive MAPK activity, and this activity was sensitive to PD153035. These data suggest that autocrine activation of the EGFR is required for the regulation of the MAPK cascade in cells minimally expressing oncogenic Ha-Ras.The Ras GTPases are critical transducers of signals that are initiated from plasma membrane receptor tyrosine kinases and terminate in the nucleus as changes in gene expression. The c-Ras 1 proteins are implicated in the regulation of multiple biological processes as diverse as cell proliferation, migration, and differentiation. In most instances, the expression of mutated, oncogenic forms of Ras results in cell transformation. The loss of normal growth control may result in the acquisition of anchorage-independent growth and a diminished requirement for exogenous serum or growth factors (1) and are intimately related to the ability of Ras to stimulate the MAPK cascade, a critical component of the proliferative response (2-6). Deregulated cell proliferation is thought to be one consequence of activated Ras signaling directly and persistently through the Raf kinases, upstream mediators of the MAPK cascade. Ras transformation can also be accompanied by the synthesis and secretion of various growth factors, including interleukin 1␣, interleukin 6 (7), TGF-␣ (8 -10), vascular endothelial growth factor (VEGF) (11), and heparin-binding EGF (HB-EGF) (12). The production of autocrine growth factors may therefore be a potentially significant mechanism contributing to the ability of activated Ras proteins to undermine the processes that regulate normal cell proliferation.We recently reported that mouse fibroblasts transformed by the minimal expression of activated (G12V)Ha-Ras (V12H10 cells) were unable to proliferate in serum-free medium in the presence of suramin, a growth factor antagonist (13-15). ...

show abstract

“…Its use in acquired immunodeficiency syndrome was based on its potential inhibition of retroviral reverse transcriptase (9) and on its ability to decrease the binding of human immunodeficiency virus to T cells (10). The polysulfate is thought to exert its anti-tumoral action by impairing the binding of growth factors to the surface receptors of malignant cells (11,12) and by inhibiting angiogenesis (13). It may also have anti-invasive properties, due to the inhibition of heparanases (1).…”

mentioning

confidence: 99%

Inhibition of Neutrophil Serine Proteinases by Suramin

Cadène

Duranton

North

et al. 1997

Journal of Biological Chemistry

View full text Add to dashboard Cite

Suramin, a hexasulfonated naphtylurea recently used as an anti-tumor drug, is a potent inhibitor of human neutrophil elastase, cathepsin G, and proteinase 3. The complexes it forms with these enzymes are partially active on synthetic substrates, but full inhibition takes place when elastase activity is measured with fibrous elastin or when cathepsin G activity is measured using platelet aggregation. One molecule of elastase binds four molecules of suramin with a K i of 2 ؋ 10 ؊7 M as determined by enzyme inhibition or intrinsic fluorescence enhancement of suramin. The binding curves show no sign of cooperativity or anticooperativity. The K i for the complexes with cathepsin G and proteinase 3 are 8 ؋ 10 ؊8 and 5 ؋ 10 ؊7 M, respectively. Ionic strength increases the K i of the elastase-suramin complex in a way that suggests that four of the six sulfonate groups of suramin form ionic interactions with basic residues of the enzyme and that at saturation almost all arginines of elastase form salt bridges with suramin. The neutrophil proteinase-inhibitory activity of suramin might be used to prevent tissue destruction and thrombus formation in diseases where massive infiltration and activation of neutrophils take place.

show abstract

Efficient reversion of simian sarcoma virus-transformation and inhibition of growth factor-induced mitogenesis by suramin.

Cited by 232 publications

References 30 publications

Ha-ras and N-ras regulate MAPK activity by distinct mechanisms in vivo

Ha-ras and N-ras regulate MAPK activity by distinct mechanisms in vivo

Oncogenic Ha-Ras-dependent Mitogen-activated Protein Kinase Activity Requires Signaling Through the Epidermal Growth Factor Receptor

Inhibition of Neutrophil Serine Proteinases by Suramin

Contact Info

Product

Resources

About