E (DAB) (K4007, Dako Corporation, CA, and U.S.A) was employed. The sections were deparaffinized in xylene, microwaved in 10 mM citrate buffer pH 6.0 to unmask the epitopes, and treated with 0.3 hydrogen peroxidase (H2O2) for 5 min to block endogenous peroxidase. The Notch1 (d1E11) XPTM Rabbit mAb (Cell Signaling, UK) and HES1 mouse monoclonal antibody (ab87395, Abcam, UK) were used in this immunohistochemistry according to the venders’ instructions. After rinsed with DAKO wash buffer the sections were incubated with hydrogen peroxide for 5 minutes, and then incubated with primary antibody for 30 GDC-0032 RG-7604 manufacturer minutes at room temperature. After another rinse with DAKO wash buffer, mouse/rabbit EnVision FLEX+Linker reagent was added and samples were incubated for 15 minutes at room temperature, followed by incubation with EnVision FLEX+HRP for 30 minutes at room temperature. The sections were rinsed, color reaction developed with DAB reagent, counterstained in hematoxylin for 20 seconds, dehydrated, and mounted under glass cover slips in preparation for evaluation under microscopy. Immunostaining was scored. Only immunoreactive intensity was considered since tumor cells, if were positive, were rather homogeneously stained. The tumors were scored as negative if no positive tumor cells were observed, and 1 was scored if the tumor cells were weakly immunoreactive, 2 was scored if the tumor cells were moderately positive and 3 was scored if the tumor cells were strongly positive.Statistical analysesThe associations between expression of studied factors and clinicopathological variables were evaluated by the Person x2 test. The Kaplan -Meier method and the log -rank test were employed to estimate and compare survival rate. For growth rate or inhibition rate analyses Student-t test was applied. All calculation was performed by usage of the SPSS 16.0 statistical software package (SPSS, Chicago, IL), and p#0.05 was considered as statistical significance.Patients and materialsIn total, one hundred and fifty-seven patients, 95 men and 62 women, who underwent potentially curative surgery with diagnosis of esophageal squamous cell carcinoma during the period of 1989?1994 at the Anyang Tumor Hospital, Henan, China, were enrolled in this retrospective study. The one hundred and fiftyseven surgically-removed specimens were routinely fixed in formalin, processed and embedded in paraffin block for diagnosis and research use. In additional, 10 normal specimens adjacent to tumor were also included in this study. This project was approved by Anyang Hygiene Bureau and Anyang Tumor Hospital for the Sino-Norwegian collaboration project [25]. All the patients gave written consensus for this research application and all the written consents were filed in Anyang Tumor Hospital, Henan, china.Results Expression of Notch family in the cell linesQuantitative RT-PCR analyses revealed rather equal amount of Notch2 in the four cell lines. Although Notch4 RNA expression in two cancer cell lines was slightly higher than the Het-1A cell line, the KYSE70 cell line expressed lower level of Notch4, and in general the Nocth4 expression in these four cell lines was low. Higher levels of both Notch1 and Notch3 RNA expression in the cancer cell lines than that in the Het-1A cell line were repeatedly verified (Figure 1A). Equal Notch2 expression and weak Notch4 expression in these four cell lines did not encourage further analyses of these two factors. Due to the fact that Notch3 was rather cle.E (DAB) (K4007, Dako Corporation, CA, and U.S.A) was employed. The sections were deparaffinized in xylene, microwaved in 10 mM citrate buffer pH 6.0 to unmask the epitopes, and treated with 0.3 hydrogen peroxidase (H2O2) for 5 min to block endogenous peroxidase. The Notch1 (d1E11) XPTM Rabbit mAb (Cell Signaling, UK) and HES1 mouse monoclonal antibody (ab87395, Abcam, UK) were used in this immunohistochemistry according to the venders’ instructions. After rinsed with DAKO wash buffer the sections were incubated with hydrogen peroxide for 5 minutes, and then incubated with primary antibody for 30 minutes at room temperature. After another rinse with DAKO wash buffer, mouse/rabbit EnVision FLEX+Linker reagent was added and samples were incubated for 15 minutes at room temperature, followed by incubation with EnVision FLEX+HRP for 30 minutes at room temperature. The sections were rinsed, color reaction developed with DAB reagent, counterstained in hematoxylin for 20 seconds, dehydrated, and mounted under glass cover slips in preparation for evaluation under microscopy. Immunostaining was scored. Only immunoreactive intensity was considered since tumor cells, if were positive, were rather homogeneously stained. The tumors were scored as negative if no positive tumor cells were observed, and 1 was scored if the tumor cells were weakly immunoreactive, 2 was scored if the tumor cells were moderately positive and 3 was scored if the tumor cells were strongly positive.Statistical analysesThe associations between expression of studied factors and clinicopathological variables were evaluated by the Person x2 test. The Kaplan -Meier method and the log -rank test were employed to estimate and compare survival rate. For growth rate or inhibition rate analyses Student-t test was applied. All calculation was performed by usage of the SPSS 16.0 statistical software package (SPSS, Chicago, IL), and p#0.05 was considered as statistical significance.Patients and materialsIn total, one hundred and fifty-seven patients, 95 men and 62 women, who underwent potentially curative surgery with diagnosis of esophageal squamous cell carcinoma during the period of 1989?1994 at the Anyang Tumor Hospital, Henan, China, were enrolled in this retrospective study. The one hundred and fiftyseven surgically-removed specimens were routinely fixed in formalin, processed and embedded in paraffin block for diagnosis and research use. In additional, 10 normal specimens adjacent to tumor were also included in this study. This project was approved by Anyang Hygiene Bureau and Anyang Tumor Hospital for the Sino-Norwegian collaboration project [25]. All the patients gave written consensus for this research application and all the written consents were filed in Anyang Tumor Hospital, Henan, china.Results Expression of Notch family in the cell linesQuantitative RT-PCR analyses revealed rather equal amount of Notch2 in the four cell lines. Although Notch4 RNA expression in two cancer cell lines was slightly higher than the Het-1A cell line, the KYSE70 cell line expressed lower level of Notch4, and in general the Nocth4 expression in these four cell lines was low. Higher levels of both Notch1 and Notch3 RNA expression in the cancer cell lines than that in the Het-1A cell line were repeatedly verified (Figure 1A). Equal Notch2 expression and weak Notch4 expression in these four cell lines did not encourage further analyses of these two factors. Due to the fact that Notch3 was rather cle.