Related Experiment Videos
A role for Ras in v-Crk transformation
1Laboratory of Molecular Oncology, Rockefeller University, New York, New York 10021, USA.
Cell Growth & Differentiation : the Molecular Biology Journal of the American Association for Cancer Research
|November 1, 1996
Summary
The v-Crk oncogene transforms cells by interacting with Ras signaling pathways. Inhibiting Ras function reverts v-Crk-induced cell transformation, suggesting Ras is crucial for this oncogene
Area of Science:
- Oncogenes and Signal Transduction
- Cellular Transformation Mechanisms
- Ras Signaling Pathways
Background:
- The v-Crk oncogene, derived from CT10 avian sarcoma virus, encodes an adaptor protein.
- v-Crk's Src homology 3 domain binds Ras guanine nucleotide exchange factors, including Sos and C3G.
- Cellular Ras contribution to v-Crk signaling was previously unevaluated.
Purpose of the Study:
- To investigate the role of cellular Ras in v-Crk-mediated cell transformation.
- To determine if Ras signaling is essential for the transformed phenotype induced by v-Crk.
Main Methods:
- Stable expression of the v-crk oncogene in NIH-3T3 cell lines.
- Treatment with a farnesylation inhibitor to block Ras function.
- Coexpression of dominant-negative Ras to inhibit Ras signaling.
- Assessment of cell morphology and colony formation in soft agar.
- Analysis of Erk (extracellular signal-regulated kinase) activity.
Main Results:
- v-Crk expression in NIH-3T3 cells induced a transformed phenotype.
- Farnesylation inhibition and dominant-negative Ras expression led to morphological reversion.
- Dominant-negative Ras inhibited colony formation without altering tyrosine phosphorylation.
- v-Crk-transformed NIH-3T3 cells showed no significant elevation in basal Erk activity.
Conclusions:
- v-Crk oncogene transformation of NIH-3T3 cells is dependent on Ras function.
- v-Crk may employ Ras effectors other than Erk to maintain the transformed phenotype.
- Ras signaling is a critical component in v-Crk-induced cellular transformation.