Expression characteristics of c-fos, c-myc and bFGF in early burn tissue.

OBJECTIVE: To investigate the sequence and characteristics of expression of proto-oncogenes, c-fos, c-myc and endogenous basic fibroblast growth factor (bFGF), in burn tissue from rats. METHODS: A partial thickness burn of 30% TBSA was created on the backs of Wistar rats. Immunohistochemistry was used to detect the expression of these proteins in normal and burned skin at 3 hours, 6 hours, 1 day, 3 days, 7 days and 14 days postburn. RESULTS: Expression of c-fos, c-myc and bFGF was induced by the burn, but these three proteins showed different expression levels in sequence and distribution. Expression of c-fos increased and peaked at 3 hours postburn. Stain positive granules were distributed mainly in the cytoplasm of basal cells and the nuclei of fibroblasts. The expression of bFGF protein increased at 6 hours and peaked at 1 day postburn; it was distributed in the cytoplasm of fibroblasts. c-myc protein peaked at 3 days postburn and was also distributed in the cytoplasm of fibroblasts. CONCLUSIONS: Thermal injury can induce c-fos, c-myc and bFGF expression and show phasic control and regional distribution. The phasic expression of these three proteins indicates that there maybe a regulatory relationship between proto-oncogenes and growth factors in early burn. This may play an important role in late tissue repair.