Expression And Significance Of ILK, PI3K And PTEN Protein In Pathologic Scar Tissue

ObjectivePathological scars include hypertrophic scar (HS) and keloid (K).It is caused by excessive proliferation and abnormal accumulation of fibroblasts in the extracellular matrix, the most important reason may be uncontrolled proliferation of fibroblast and its apoptosis.Integrin-linked kinase (ILK) is a Ser/Thr protein kinase. It can be activated by P13K and down-transmit extracellular signals by phosphorating downstream substrate protein kinase B (PKB), then regulate the cell growth,cell differentiation,apoptosis, cell cycle and cell adhesion and play an important role in the matrix accumulation, development of tumor and fibrotic diseases.The PTEN,which can dephosphorate specifically 3,4,5-triphosphate, phosphatidylinositol (phosphatidylinositol3,4,5-triphosphate, PIP3) to antagonise PI3K/ILK/AKT pathway, regulate cell growth, proliferation, migration, differentiation and many other effects.Many people have researched the relationship between ILK and tumor in recent years. Some studies have shown that it can be through the activation of PTEN/PI3K/ILK/PKB signaling pathway to accelerate tumor cell proliferation and differentiation. Little studies have been done in pathological scars.This particular research is to study the expression of ILK, PI3K, PTEN and their relations in 40 patients with pathological scars.Effective method for early prevention of pathologic scars and providing theoretical basis for gene therapy has been found.Materials and methods40 cases of pathologic scars were taken as the experimental group from the period of 2007-2009.The pathologic scars were all from prominent surfaces and obtained from chest, back, perineum and ears.20 cases which were of normotrophic type had no flare or itch and were soft and flat. They were all obtained from cleft lip and external injury patients.20 cases of normal skin form residual full thickness skin grafts or cosmetic surgery were chosen as control group.The S-P immunohistochemical technique was used to detect the expression of ILK, PI3K and PTEN in the development of pathologic scars.The statistics data were processed by SPSS13.0, using Chi-square test and Dependability analysis.The standard deviation is 0.05.Results1 The positive expression of ILK was mainly localized in the cytoplasm of fibroblasts. The positive rates in pathologic scars were 67.50%(27/40), and 25.00%(5/20) in non-pathological scar,15.00%(3/20) in normal skin. There was a statistical significance between the pathologic scars and normotrophic scars or normal skin (p <0.0167).There was no statistical significance between normotrophic scars and normal skin (p>0.0167).2 In pathologic scars group, PI3K protein was mainly expressed in the cytoplasm of fibroblasts.The positive rates of PI3K were 70.00%(28/40),35.00%(7/20),25.00% (5/20),respectively in pathologic scars, normotrophic scars and normal skins. There was a statistical significance between the Pathologic scars and the other two groups in the expression of PI3K (p<0.0167).There was no statistical significance between normotrophic scars and normal skin (p>0.0167).3 The positive expression of PTEN was mainly localized in the nucleus of epidermal cells and part of blood vessel endothelial cell.The positive rates of PTEN were 25.00%(10/40),70.00%(14/20),95.00%(19/20),respectively in pathologic scars, normotrophic scars and normal skins. There was a statistical significance between the pathologic scars and the other two groups in the expression of PTEN (p<0.0167). There was no statistical significance between normotrophic scars and normal skin (p>0.0167).4 Corelativity analysis showed the expression of ILK and PI3K was negatively co related with PTEN (p<0.05),the expression of ILK was positively correlated with PI3K (p<0.05).Conclusions1 The high expression of ILK in the fibroblast of pathologic scar indicated that they may be in the promotion of fibroblast proliferation and protect the fibroblast from apoptosis, which involved in the formation of pathological scars.2 PI3K, as an important signal factor of PI3K/PTEN/ILK signaling pathway, plays a great role in the formation of pathological scars together with ILK.3 PTEN may inhibit the expression of ILK and play a prohibitive role in pathologic scar formation in the signaling pathway of PI3K/ILK/PKB.4 ILK, PI3K and PTEN protein might be involved in the formation of pathologic scar through the activation of PTEN/PI3K/ILK/PKB signaling pathway to accelerate fibroblast proliferation. PI3K and ILK proteins may cooperate to promote the progress of pathologic scar.