ObjectiveTo investigate the expressions ofβ-catenin and glycogen synthase kinase 3 beta(GSK-3β) proteins in the gastric carcinomas and to elucidate their clinical significance.Methods The expressions of β-catenin and GSK3-β proteins were analyzed with immunohistochemistry staining of gastric tissue array in the normal gastric mucosa (n =48),paracancerous tissues ( n =24),and primary cancer tissues ( n =48).ResultsThe positive expression rate ofβ-catenin and GSK-3β in gastric carcinomas was 66.7％ and 35.4％,respectively,and β-catenin protein expression in carcinomas was higher than normal and paracancerous tissues ( x2 =65.455,P ＜ 0.05 ).The expression of β-catenin was correlated with cell differential degree,pTNM stage,histological type,lymph node memtastasis,and nerve invasion,respectively ( x2 =4.713,8.242,13.662,11.658,4.550,P ＜ 0.05 or P ＜ 0.01 ).The positive expression rate of GSK3βin carcinomas was lower than normal and paracancerous tissues ( x2 =26.968,P ＜ 0.05).The expression of GSK-3β was correlated with cell differential degree,histological type,and lymph node metastasis,respectively (x2 =3.868,9.665,9.872,P ＜ 0.05 or P ＜ 0.01 ).The expression of β-catenin was negatively correlated with the expression of GSK-3βprotein in the gastric carcinoma tissues ( r =-0.493,P =0.001 ).ConclusionsGSK3-β and β-catenin might play important roles in the progression,differentiation,infiltration,lymph node metastasis of gastric carcinoma,and might be the indicators for diagnosis of a gastric carcinoma.

Objective It was designed to investigate the relationship between the productions of p16 and Rb genes expression and gastric carcinogenesis and evaluate the correlation between the expression of p16 and Rb genes in gastric carcinoma.Methods The expression of P16 and Rb proteins was examined in gastric carcinoma and precancerous lesion and normal gastric mucosa by streptavidin-peroxidase immunohistochemical method (S-P).Results The positive rates of P16 and Rb proteins expression showed as below: There were 96 25%(77/80) and 98 75%(79/80) in normal gastric mucosa, 92 00%(46/50) and 80 00%(40/50) in atypical hyperplasia gastric mucosa and 47 54%(58/122) and 59 84%(73/122) in gastric carcinoma respectively. The positive rates of P16 and Rb proteins expression in gastric carcinoma were significantly lower than that in normal gastric mucosa and atypical hyperplasia gastric mucosa (P

Objective To establish two-dimensional electrophoresis profiles with high resolution and reproducibility from human gastric carcinoma and paired normal gastric mucosa tissues and to analyse the differential expression proteins between the two types of the tissues. Methods The total proteins of gastric carcinoma and paired normal gastric mucosa tissues were seperated by immobilized pH gradient-based two-dimensional gel electrophoresis (2-DE).After silver staining, the differential expression proteins were analyzed by using Imaging Master 2D analysis software. Results ⑴Average protein spots were 1049?67, 1097?73 in gastric carcinoma and paired normal gastric mucosa respectively,the matched spots were 835?48, 953?56 in both the two types of tissues respectively, and the average matching rate was 79.6%, 86.7% respectively. ⑵A total of 769?45 protein spots were matched between the electrophoretic maps of 5 gastric carcinoma and paired normal gastric mucosa tissues. The 81 differential protein spots were identified between the two types of the tissues. 17 protein spots were expressed only in the gastric carcinoma and 24 protein spots were expressed only in the normal gastric mucosa. The expression levels of 26 protein spots in the gastric carcinoma were higher than those in the normal gastric mucosa, and the expression levels of 14 protein spots in the gastric carcinoma were lower than those in the normal gastric mucosa. Conclusion In this study, the well-resolved,reproducible 2-DE patterns of gastric carcinoma and paired normal gastric mucosa tissues were established and some differential proteins between the two types of tissues were found. These data will be helpful to further screen specific biomarkers of gastric carcinoma.

Objective:To investigate the effect of exogenous extopic fragile hisdidine triad (FHIT) gene on the apoptosis of gastric cancer cells induced by octreotide and elucidate the underlying mechanism. Methods: Human gastric cancer cell line MGC-803, which was loss of FHIT gene, was transfected with plasmid pRcCMV-FHIT and pRcCMV via lipofectamine mediation. After transfection, Western blotting was used to analyse the expression of FHIT protein in positive cells screened out by G418. The cells were treated with octreotide 10~(-10), 10~(-9), 10~(-8), 10-7, and 10~(-6) mol/L for 24, 48 and 72 h. Cell proliferation was evaluated by MTT assay and apoptosis by flow cytometry. The expression of bcl-2 and bax protein was detected with Western blotting.Results:FHIT protein expression was detected in MGC-803 gastric cancer cells after FHIT gene transfection. After treatment with octreotide 10~(-8) mol/L for 48 h, the apoptotic rate of MGC-803 cells transfected with FHIT gene was (26.777±1.702)%, significantly higher than that in empty vector group and untransfected group [(13.800±0.511)% vs (12.634±0.479)%, F=245.789, P<0.05]. The expression of bcl-2 protein was decreased while the expression of bax protein was increased in FHIT gene transfection group after octreotide treatment. Conclusion:The exogenous FHIT gene and octreotide had strong synergistic effects on apoptosis of MGC-803 cell lines, and their action mechanism may be related to the alteration of the expression of apoptosis-related proteins of bcl-2 family.

Objective This study aimed to investigate the expression of Cyclin E protein in the progress of occurrence and development of gastric cancer and lymphonode metastatic cancer.Methods The expression of Cyclin E protein analyzed by immunohistochemistry in gastric tissue array included of normal gastric mucosa,cancer side tissues,atypical hyperplasia tissues,primary cancer tissues and lymphonode metastatic cancer tissues.Results The positive expression rate of Cyclin E protein was 14.3％,20.0％,34.7％,85.1％ and 82.9％ in normal gastric mucosa,atypical hyperplasia tissue,carcinoma side tissue,primary cancer and lymphonode metastatic cancer,respectively.Compared with normal gastric mucosa and carcinoma side tissues and atypical hyperplasia tissues,the Cyclin E protein in primary cancer and lymphonode metastatic carcinoma tissues was over-expression ( P ＜ 0.01 ).Conclusions The Cyclin E protein was a possible molecular marker that can be used to diagnosis gastric cancer and lymphaden metastasis cancer.

Background and purpose:As a new candidate tumor suppressor gene, p33ING1b has many biological functions. This study was done to investigate its role in the regulation of the proliferation of human colon cancer cell line SW480. Methods:The pcDNA3.1(+)/p33ING1b/SW480 cells were identified by Western blot and S-P immunohistochemical method. In order to elucidate the effect of expression of exogenous p33ING1b gene on the colorectal cancer cell SW480, the proliferation rates were analyzed by growth curves and colony formation assay in soft agar for cells including SW480, pcDNA3.1(+)/p33ING1b/SW480 and pcDNA3.1(+)/SW480. At same time, the apoptotic rate of cells and the cell cycle analysis were also tested by flow cytometry.Furthermore,using western blot analysis,we detected the expression level of the protein p53, p21WAF1,Bax and Bcl-2 in those three group cells, which initially indicate the molecule mechanism of inducing apoptosis by gene p33ING1b. Results:The cell growth rates of SW480 cells transfected with pcDNA3.1 (+)/p33ING1b were slower than those transfected with pcDNA3.1(+) or untransfected.The colony formation efficiency of pcDNA3.1(+)/p33ING1b/SW480 were decreased and the apoptotic rates were increased compared with pcDNA3.1(+)/SW480 and SW480(P0.05). Conclusion:After overexpression of exogenous p33ING1b protein in SW480 cell, there were inhibition of the proliferation rate and induction of apoptosis, the molecular mechanism might be associated with up- regulated expression of Bax and down-regulated expression of Bcl-2 by p33ING1b gene.

STGC3, a novel tumor related gene, was cloned recently. The previous studies indicated that STGC3 can inhibit the proliferation of CNE2 cell line in vitro. To examine the effect of STGC3 on the tumorigenicity of CNE2 cell line and explore its mechanism in nude mice. The Tet/pTRE/CNE2-STGC3 cell line was planted under the front leg skin of nude mice and induced by doxycycline (Dox). The mRNA and protein level of STGC3 in transplanted tumor tissues were detected with RT-PCR and Western Blotting. The apoptosis ratio of the tumor cell was analyzed with flow cytometry. STGC3, Bcl-2 and Bax proteins were examined by immunohistochemistry method. The results indicated that high level of STGC3 expression can inhibit tumorigenicity of CNE2 cell line in nude mice. Tumor grew slowly, later and smaller. Cell apoptotic percentage increased. Bcl-2 protein expression was down-regulated and Bax protein expression was up-regulated in Tet/pTRE/CNE2-STGC3 cell line (P

In an attampt to establish the functional expression of STGC3 with doxycycline (Dox) induced Tet-onregulating system in human nasopharyngeal carcinoma cell line CNE2, an ideal experimental platform wasprovided for further studies of STGC3. pTet-on regulating plasmid was transfected into CNE2, and stableexpression of Tet-on was established in CNE2 through G418 select. Then the response plasmid of recombinantpTRE-STGC3 was steadily transfected into positive CNE2/Tet-on cells with hygromycin screen. Dox was used toinduce the expression of STGC3 and a cell clone sensitive to Dox was selected. The best-induced concentrationwas determined with different concentration of Dox induction. Growth curves, clone formation rate and cell cycledistribution were detected after STGC3 gene up-regulated expression with Dox induction. The growth capacity andclone formation potential of CNE2/Tet /pTRE-STGC3 was significantly suppressed, compared with the controls(P

Aim To investigate the arrest effect of diallyl disulfide(DADS) in the cell cycle of human nasopharyngeal carcinoma SW480 cell line and its molecular mechanism.Mothdes The growth inhibition effect of DADS of different concentrations on SW480 cell line was measured by MTT assay and cell counting.Phase distribution of cell cycle was analyzed by flow cytometry.Expression of Ubiquitin and FKBP was determined by Western blot.Results The MTT assay showed that DADS inhibited growth of SW480 cells significantly in a dose-dependent manner.Adding 25,35,50 and 70 mg?L-1 DADS for 48 hours,SW480 cell growth was suppressed by 18.67%,33.02%,49.12% and 66.86%,respectively.There were significant differences between the treated and controlled cases(P