| Background: Gastrointestinal stromal tumors (GISTs) are the most commonmesenchymal neoplasms of the digestive tract, but their pathogenesis isnot distinct and there is no special morphologic criterion to predict thebiologic behavior of GISTs. There is no unanimous standard to regularizemalignant degree of GISTs.Objective: P16, Mdm2, E2F1 and RB are cell cycle regulation proteins.Our aim is to find useful index of predicting malignant potential bymeasuring the expression of P16, Mdm2, E2F1 and RB in GISTs.Method: Forty patients with gastrointestinal stromal tumors were studied.Seven of them were taken from endoscopic resection, thirty three were takenfrom operation. HE and immunohischemical staining were carried out in allsamples. Thirty one patients were followed up for 6～35 months. The tumorscan be classified into benign, interface and malignant groups based on tumorsize, mitotic count, necrosis and infiltration. The expression of P16, Mdm2,E2F1 and RB in three groups were measured by immunohischemical staining.Determining positive result: there are palmpellets in positive cells. Halfwayquantitative analysis was carried out according to Fromowitz method. Negativeand positive controls were established.Result: The positive rate of the expression of P16, Mdm2, E2F1 and RBin GISTs are 57.5%, 40%, 60%, and 45%.The expression of E2F1 wassignificantly higher in malignant GISTs, but that of P16 was significantlyhigher in benign GISTs. The expression of Rb was more common in malignantGISTs, Mdm2 was more common in benign, but the differences were not significant in the three groups. The expression of pl6 in the GISTs withrecurring and metastasis are significantly lower. The expression of p16was significantly related with mitotic count and the expression of E2F1.Conclution:1,The expression of P16, Mdm2, E2F1 and RB are important to predictthe prognosis of GISTs. P16 and E2F1 of them are more valuable.2,The low expression of p16 and the high expression of E2F1 meansthe higher malignant degree of GISTs. The low expression of p16 isassociated with higher recurring, metastasis and death rate in GISTs. |
