ABSTRACT
Objective: To study the expression of Fas, Fas ligand (FasL) and IFN ? in gastric cancer and its possible significance. Methods: Fifty eight gastric paraffin wax embedded cancer tissues and fifty three normal tissues adjacent gastric cancer were tested for the expression of Fas and FasL protein by immunohistochemistry and IFN ? mRNA by in situ hubridisation respectively. Results: The positive rate of Fas in cancer cells of gastric cancer tissues was significantly lower than that in gastric epithelial cells of the tissues adjacent cancer(19.0% and 64.2%, respectively; ? 2=23.46, P = 0.00). The positive rate of FasL in cancer cells of gastric cancer tissues was significantly higher than that in gastric epithelial cells of the tissues adjacent cancer(63.8% and 45.3%,respectively; ? 2=3.83, P =0.05). The positive rate of IFN ? in cancer cells of gastric cancer tissues was significantly lower than that in gastric epithelial cells of the tissues adjacent cancer(0.0% and 49.1%,respectively; ? 2=37.16, P =0.00). Conclusion: The Fas-FasL system was unbalanced, and the expression of IFN ? was low in gastric cancer cells in this study. These may be related to the carcinogenesis of gastric epithelial cells and might be responsible for the immune escape of these cells.
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Objective To investigate the role of loss of heterozygosity (LOH) of SMAD2 and its relationship with clinicopathological parameters of primary gastric carcinoma. Methods Fifty cases of primary gastric carcinoma were monitored by polymerase chain reaction -single strand conformation polymorphism (PCR- SSCP) and silver staining to detect SMAD2 LOH. Results The incidence of LOH was 40.0%(22/45) at D18S450 and 33.3%(16/48)at D18S460 . LOH occurred in SMAD2 was 55.1%(27/49).The rate of SMAD2 LOH was 72.0% (18/25) in primary gastric carcinoma with lymph node metastasis , which was significantly higher than that in without lymph node metastasis (P
ABSTRACT
Objective To determine the biological effect of p27 KIP1 on gastric carcinoma cells SGC7901. Methods The total length of p27 KIP1 cDNA was transfected into human gastric cancer cells SGC7901 by lipofectin transfection. Expression of p27 KIP1 in protein or mRNA level was examined by Western blotting and RNA dot blotting respectively. Effect of p27 KIP1 on cell growth was observed by trpan blue exclusion assay. Tumorigenicity test in nude mice was applied to assess the biological effect of p27 KIP1 in vitro. Results Expression of p27 KIP1 in protein or mRNA increased evidently in SGC7901 cells transfected with p27 KIP1 . The cell growth was reduced by 42% about 48h after the induction with Zn 2+ ,which was determined by cell viability assay. The tumorigenicity of nude mice was reduced evidently(P