Expression Of Survivin Gene And Its Relationship With Expression Of C-myc, P27～(kip1) Proteins In Pathologic Scar

Pathologic scar is a particular fibro-metabolic disease of derma in human being which is characterized by excessive proliferation of fibroblasts and accumulation of collagen together with other extracellular matrix resulting from wound, infection, and burns etc. It includes hypertrophic scar and keloid that both are similar in histology. It's clinical characteristic involve dysaesthesia, tumor-like growth and a certain extent functional impediment etc. The pathogeny and formative mechanism of pathologic scar are very complication and the therapy is a medical difficult problem for surgery. So to investigate the mechanism of formation in pathologic scar is still a groping focus in the field of plastic surgery at present. Along with the development of cellular biology and molecular biology and it gets involved in the scar formation realm, studying to the formation of pathologic scar and the relativities to oncogene, cytokine ,and apoptosis are developed in the all new path. The turbulence of proliferation or apoptosis of fibroblasts, unbalance of synthesis or degradation of collagen, a great deal of creation of cytokines and the affinity among the above three factors constituted the biological foundation of pathologic scar. The disorder of regulation of proliferation or apoptosis of fibroblasts is considered as an important causation to the mechanism of formation in pathologic scar. Many genes, which contribute to the regulation of proliferation and apoptosis of fibroblasts, to the synthesis and degradation of collagen, are cloned one after the other. Function of the genes are clarified gradually also. The research about expression of proto-oncogenes, anti-oncogenes and the relational genes of apoptosis in pathologic scars will establish a scientific academic base to understand the mechanism of formation.The Survivin gene can restrain cell apoptosis, promote cell proliferation, and participate blood vessel formation. It operate confluent dot of every apoptosis routh and strongly restrain cell apoptosis of inducement over expression of Caspase 3 or Caspase 7. The effect of c-myc gene is germane with cell division, proliferation, differentiation, apoptosis. c-myc oncogene is activated in pathologic scar, which may contribute to proliferation differentiation and apoptosis of fibroblasts, to synthesis and degradation of collagen and to regulation of cytokines. p27 has been found associated with the G₁ cell cycle period and appears to play a major role in the regulation of CDK complex activity in this phase of the cell cycle. It can restrain the activity of cyclinE-CDK2 and cyclinD-CDK4 complex, thus controling the cell proliferation. Over expression of p27 in mammalian cells induces a G1 block of the cell cycle. From the above we can find that Survivin, c-myc, and p27 genes relate with the regulation of cell apoptosis and proliferation of fibroblasts. But their expression, significance or interrelation are still not clear in pathologic scar. So we adopt in situ hybridization, immunohistochemical methods (SP technique) to detect separately Survivin mRNA, c-myc protein, p27klplprotein in 40 pathologic scar cases, 20 normotrophic scar cases, 20 normal skin cases. The ralationship between the expression of Survivin mRNA and c-myc protein or p27kipl protein in 40 pathologic scar cases were also analyzed. The study may reveal the correlation between the expression of key oncogenes playing major roles in tumorigenic process and abnormal scarring. It will provide theoretic base for preventing and treating pathologic scar in the new way.Materials and methods:The tissues of pathologic scar and normotrophic scar were obtained from the patient who were underwent plastic surgery in the first affiliated hospital of zheng zhou university etc. The tissues were collected from face, neck, chest, and limbs etc. The normal skin tissues were acquired in the operation of skin transplantation. The tissues were collected from limbs, abdomen, and back etc. All the tissues were required to accord with the principles: particular case history and feedback record; therapy out of radiation, laser, or immunity; the pathologic confirmation. The number of pathologic scar, normotrophic scar, and normal skin tissues are 40, 20, and 20 .Thesitu hybridization and immunohistochemical methods (SP technique) were used to detect the function and expression of Survivin mRNA, c-myc protein, and p27kipl protein in pathologic scar, normotrophic scar, and normal skin cases. The relationship between the expression of Survivin mRNA and c-myc protein or p27kipl protein in pathologic scar cases were also systematically analyzed. The statistical analysis were executed by SPSS 11.0 software. P values less than 0.05 are considered significant. Results:l.The expression of Survivin mRNA in pathologic scar, normotrophic scar and normal skin tissuesThe positive expression of Survivin mRNA were mainly localized in the cytoplasm. In pathologic scar, the positive signal were mostly concentrated in the fibroblast of collagen knur or swirl configuration and other positive signal lied in parts of the blood vessel endodermis cells and fundus cells. The positive rate in the pathologic scar tissues was 67.50% (27/40) ,and 40.00% (8/20X 20.00% (4/20) in normotrophic scar and normal skin tissues respectively. Compare with normotrophic scar and normal skin cases, the expression of Survivin mRNA were significant difference in pathologic scar cases (P<0.05) .But there were no significant difference in the expression of Survivin mRNA between the normotrophic scar and normal skin cases(P>0.05) .2. The expression of c-myc protein in pathologic scar, normotrophic scar and normal skin tissuesIn normal skin tissues, the positive expression were mainly localized in the cytoplasm or karyon of epidermal fundus cells and blood vessel endodermis cells. The positive expression were also localized in the cytoplasm or nuclei of most fibroblast besides this in the pathologic scar tissues. The positive rate in the pathologic scar tissues was 72.50% (29/40) ,and 45.00% (9/20X 35.00% (7/20) in normotrophic scar and normal skin tissues respectively. Compare with normotrophic scar and normal skin cases, the expression of c-myc protein were significant difference in pathologic scar cases (P<0.05) .But there were no significant difference in the expression of c-myc protein between the normotrophic scar and normal skin cases (P >0.05) .3. The expression of p27kipl protein in pathologic scar, normotrophic scar and normal skin tissuesIn normal skin tissues, the positive expression were localized in the karyon or cytoplasm of great mass of fibroblasts n most epidermal cells and blood vessel endodermis cells. The positive rate reached 90.00% (18/20) in normal skins group. There were a sharp fall in pathologic scars group, the positive rate was 55.00% (22/40) . Compare with normotrophic scar and normal skin cases, the expression of p27kipl protein were significant difference in pathologic scar cases (P<0.05) .But there were no significant difference in the expression of p27kipl protein between the normotrophic scar and normal skin cases (P>0.05) .4. The correlation analyse of the expression of Survivin mRNA, c-myc protein, and p27kipl proteinThe results of analysis of correlation of the expression in the pathologic scars group indicate that Survivin has significant correlation with expression of c-myc and c-myc has correlation with expression of p27 (P<0.05) , but Survivin has no significant correlation with expression of p27 (P>0.05) . Conclusions:1. The up-regulation of Survivin mRNA in the pathologic scar suggests that the Survivin gene may inhibit the apoptosis of fibroblasts and blood vessel endodermis cells. The Survivin gene may correlate with the formative mechanism of pathologic scars.2. c-myc oncogenes are activated in pathologic scar, which may contribute to proliferation > differentiation and apoptosis of fibroblasts and may participate in the regulation of cytokines. This may induce the formation of scars.3. The expression of p27 may be a essential factor which control the proliferation of fibroblasts in normal skin. The low expression of p27 protein may change the regulation of CDK complex activity and result in the abnormal proliferation of fibroblasts in the pathologic scars.4. The expression of Survivin and c-myc might play synergetic roles in the process of forming of pathologic scar. The expression of Survivin and p27 might have no synergetic function in the different restrictive spot of the cell cycle. The transcriptionof the p27 gene may be inhibited by c-myc gene.