OBJECTIVETo study the relation of the mRNA and protein expression of Cyclin A and p21cip1 in different stages hypertrophic scar fibroblast (FB) with its cell cycle, so as to provide theoretical evidence for intervention therapy of cell cycle gene being used in hypertrophic scar.

METHODSThe hypertrophic scar samples at different stages (the third month, the sixth month, the twelfth month, the twenty-fourth month) in 32 cases and the normal skin samples in 8 cases were used in this study. The expression of Cyclin A, p21cip1 mRNA and protein was detected by quantitative real-time PCR and Western Blot. And at the same time, the flow cytometer was used to detect the fibroblastic cell life cycle.

RESULTS1) The expression of Cyclin A mRNA and protein in the third month group, the sixth month group, the twelfth month group, the twenty-fourth month group were 19.34 +/- 2.41, 0.99 +/- 0.11; 19.30 +/- 1.42, 0.96 +/- 0.09; 10.73 +/- 2.93, 0.66 +/- 0.58; 9.29 +/- 0.97, 0.65 +/- 0.14, respectively. And in corresponding stages, the expression of p21cip1 mRNA and protein were 2.80 +/- 0.69, 0.35 +/- 0.07; 4.95 +/- 1.82, 0.44 +/- 0.07; 9.98 +/- 1.19, 0.56 +/- 0.06; 10.25 +/- 1.46, 0.59 +/- 0.06, respectively. The expression intensity of Cyclin A mRNA and protein was no significantly different between the third month group and the sixth month group (P > 0. 05), but it was higher respectively than that in the twelfth month group, the twenty-fourth month group and normal group (P < 0.05). And the expression intensity was no different between the above three groups (P > 0.05). The expression intensity of P21cip1 mRNA and protein in the third month group was lower than that in the sixth month group, but that in the above two groups was lower respectively than that in the twelfth month group, the twenty-fourth month group and normal group (P < 0.05). And the expression intensity had no difference between the three later stage groups (P > 0.05). 2) Most FB were in S and G2/M stage (cycle) in 3rd month, 6th month group. And most FB were in G0/G1 stage (cycle) in 12th month, 24th month group and normal group.

CONCLUSIONSThe expression of mRNA and protein of Cyclin A in hypertrophic scar changes from high level to low level as the hypertrophic scar develops, while the expression of P21cip1 changes from low level to high level. The mRNA and protein expression of Cyclin A and p21cip1 respectively are basically corresponded to different stages of hypertrophic scar. The distribution of cell life cycle of fibroblastic are also corresponded to the expression intensity of Cyclin A and p21cip1 in different stages hypertrophic scar. An early stage intervention to the two gene can be effective to prevent from the genesis and development of hypertrophic scar.