Résumé
Objective: To investigate the changes of the small G protein RhoB expression in scalded rat livers and heat-stressed human prostate cancer cell line PC-3, so as to discuss the influence of heat stress on expression of RhoB in vitro and in vivo. Methods: Third degree burns of 30% total body surface area (TBSA) model was established with SD rats on the back. The expression of RhoB mRNA and protein in the liver was determined by RT-PCR and Western blot 2 h, 4 h, 8 h and 16 h (n=6) after scalding; the liver tissues of normal rats were taken as control (n=6). PC-3 cells were allowed to recover for 0.5 h, 1 h, 2 h, 4 h and 8 h in a cellular heat stress model and the expression of RhoB in mRNA and protein were determined by RT-PCR and Western blot, respectively; untreated PC-3 cells were taken as control. Results: The expression of RhoB mRNA in the livers peaked 4 h after scalding, being about 3.2 folds that of the control group (P<0.01); the expression began to decline 8 h after scalding. The expression of RhoB protein peaked 8 h after scalding, significantly higher than that of the control (P<0.01). RhoB mRNA level began to increase 2 h after heat stress treatment and peaked at 4 h, being about 2. 8 folds that of the control (P<0.01). The expression of RhoB protein reached its maximum at 8 h after heat stress treatment (P<0.01). Conclusion: Heat stress can up-regulate the expression of RhoB mRNA and protein in vivo and in vitro.