Fig. 2. Upregulation of Rho GTPase protein expression by hypoxia in renal cell carcinoma. Caki-1 cells were exposed to 1% O₂ from 0 to 6 hours. Post-nuclear supernatants (20 µg of protein) were separated by SDS-PAGE and submitted to immunodetection using Cdc42, Rac1, RhoA, RhoGDI and RhoB antibodies (A). The expression of these Rho GTPases was quantified by densitometric analysis and expressed as means ± s.e.m. for three separate experiments relative to normoxic values (B). Significant differences (P<0.05) from normoxia are indicated by asterisks (*).