MATERIALS AND METHODS Patients From January 2005 through December 2009, 134 patients were initially diagnosed as having mesenchymal gastrointestinal inhibitor Trichostatin A tumors at Jilin University First Hospital. Thirty-three patients were excluded from the study due to recurred tumors or the tumors being partially resected. Thus, 101 patients underwent successful surgical operations for complete resection of tumors. Following the surgery, patients with high-risk and intermediate risk were treated with imatinib (Glivec?, Novartis Pharmaceuticals, Basel, Switzerland) at a dose of 400 mg/d for 3 years. No imatinib treatment was given before the surgery. Five cases were lost to follow-up. Ninety-six patients were retrospectively evaluated in the study.
Informed consents were obtained from all patients and the study was approved by the local human ethical committee of Jilin University First Hospital. Original hematoxylin and eosin-stained sections were reviewed in each case by two pathologists (Jin MS and Wang YP) according to GIST characteristics described by Miettinen[14]. All tumors from 96 patients were confirmed to be GISTs based on a combination of histological evaluations (highly cellular spindles/epithelioids/mixed cell tumors), and c-kit, DOG1, CD34 positive staining. The clinical information regarding the patients is summarized in Table Table11. Table 1 Clinicopathological features of 96 patients with gastrointestinal stromal tumor Immunohistochemical analysis Histological sections (4 ��m) of 10% formalin-fixed, paraffin-embedded material were used for immunohistochemical staining.
Prior to a primary antibody staining, the slide was pretreated with citric acid or ethylenediaminetetraacetic acid buffer in a pressure cooker for antigen retrieval. Endogenous peroxidase activity was quenched by 3% H2O2 blocking reagent for 10 min. The Batimastat slide was incubated with a primary antibody at 4 ��C overnight, and then immunostained with the avidin-biotin peroxidase complex (DAKO, CA). Finally, the slide was stained with diaminobenzidine according to the manufacturer��s protocol (DAKO, CA). The slide was rinsed three times with phosphate buffered saline after each step of staining. The sections were stained with primary antibodies against c-kit (Clone: YR145, dilution: 1/50, Cell Marque Corporation, CA), CD34 (QBEnd/10, dilution: 1/100, Neomarkers, CA), Ki-67 (MIB-1, dilution: 1/100, DAKO, Carpinteria, CA), DOG1 (SP31, dilution: 1/100, Spring Bioscience, Pleasanton), SMA (IA4, dilution: 1/200, Cell Marque Corporation, CA), p27 (1B4, dilution: 1/20, Novocastra), p53 (SP5, dilution: 1/100, Zymed Laboratories, San Francisco), S-100 (6E6, dilution: 1/100, Neomarkers, CA), Desmin (D33, dilution:1/50, Cell Marque Corporation, CA), EGFR (EGFR.