Related Experiment Videos
Transformation by the oncogene v-fms: the effects of castanospermine on transformation-related parameters
E J Nichols1, R Manger, S I Hakomori
1Fred Hutchinson Cancer Research Center, Division of Basic Sciences, Seattle, Washington 98104.
Abstract:
The effects of castanospermine on various parameters associated with transformation were examined in cells expressing the viral oncogene v-fms. Fischer rat embryo (FRE) cells transformed by the oncogene v-fms and grown in the presence of castanospermine reverted to a more normal cell morphology and accumulated fms protein within the endoplasmic reticulum. Treated cells attained contact inhibition of cell growth at a much lower cell density compared to the untreated controls. No effect of castanospermine on cell growth was observed for FRE cells transformed by a different oncogene v-fgr. Castanospermine-treated SM-FRE (v-fms transformed) cells reexpressed extracellular matrix fibronectin and exhibited an extensive actin-containing cytoskeleton similar to that of normal nontransformed FRE cells. Castanospermine treatment of SM-FRE cells resulted in a sixfold decrease in [3H]deoxyglucose uptake compared to that of the nonreverted SM-FRE cells. Again, no effect was observed in FRE cells transformed by the oncogene v-fgr (GR-FRE). These results further characterize the reversion caused by castanospermine and indicate that cell surface expression coordinately controls anchorage independent growth, cell morphology, contact inhibition of growth, and hexose uptake.
Insights
Castanospermine treatment reverted v-fms transformed cells to a normal phenotype, restoring cell morphology and growth control. This suggests castanospermine influences cell surface expression, affecting key transformation parameters.
Area of Science:
- Cell Biology
- Biochemistry
- Molecular Oncology
Background:
- Viral oncogenes drive cellular transformation, leading to aberrant cell growth and morphology.
- Castanospermine is an alkaloid known to affect glycoprotein processing.
Purpose of the Study:
- To investigate the effects of castanospermine on v-fms-transformed Fischer rat embryo (FRE) cells.
- To determine if castanospermine-induced reversion is specific to the v-fms oncogene.
Main Methods:
- Treatment of v-fms and v-fgr transformed FRE cells with castanospermine.
- Analysis of cell morphology, fms protein localization, and fibronectin expression.
- Assessment of cell growth, contact inhibition, and hexose uptake.
Main Results:
- Castanospermine treatment induced reversion to normal morphology in v-fms transformed cells, with fms protein accumulation in the endoplasmic reticulum.
- Reverted cells exhibited restored contact inhibition, fibronectin expression, and actin cytoskeleton.
- Castanospermine significantly decreased [3H]deoxyglucose uptake in reverted cells, with no effect on v-fgr transformed cells.
Conclusions:
- Castanospermine induces reversion of v-fms transformed cells, characterized by altered cell morphology and restored growth control.
- The effects of castanospermine are specific to v-fms transformation, highlighting its role in modulating specific oncogenic pathways.
- Cell surface expression appears to be a key regulator of anchorage-independent growth, morphology, contact inhibition, and hexose uptake.