The Expression And Significance Of PTEN, S-phase Kinase-associated Protein2 And P27^Kip1 In Gastrointestinal Stromal Tumors

Objective:To investigate the expression of PTEN,Skp2 and p27^Kip1 in gastrointestinal stromal tumors(GIST) and to explore the role of all these expression in the occurrence and development of GIST.Methods:Clinicopathologic features and immunohistochemical expression of PTEN,Skp2 and p27^Kip1 were studied in 48 patients with GIST and 8 normal persons.Results:1.There were no obvious difference of the expression of PTEN,Skp2 and p27^Kip1 between the normal group and low risk group(P＞0.05),but their expression in the former two groups were significantly difference with high risk group(P＜0.05).2.Tumor with larger size and more mitotic index,have the higher expression of Skp2 and the lower p27^Kip1 expressions.The more mitotic index was,the lower PTEN expression.3.Expression levels of PTEN and p27^Kip1 were lower in high risk GIST compared with low risk GIST,whereas expression levels of Skp2 were significantly higher in high risk GIST but lower in low risk GIST.No correlation was found between the expression levels of PTEN and p27^Kip1,both of which were inversely related to Skp2 levels(r=-0.332,P＜0.05;r=-0.599,P＜0.01).Conclusions:The tumor suppressor genes PTEN and p27^Kip1 may play an important role in suppression of the occurrence of GIST.The expression levels of Skp2 and p27^Kip1 may be associated with the size and mitotic index of GIST;the expression levels of PTEN may be associated with the mitotic index of GIST.The overexpressing of Skp2,inactivation of PTEN and p27^Kip1 maybe a middle or later event in the development of GIST,and the three genes may be in cooperation with each other in the process.Detecting these three genes simultaneously in GIST may reflect the patient prognosis. KEY WORDS gastrointestinal stromal tumors,PTEN,S-phase kinase-associated protein2,p27^Kip1,immunohistochemistry...