Significance Of Golgi α- Mannosidase Ii, E-cadherin,galectin-3 Expression And Their Correlation In Human Gastric Carcinoma

Objective : To investigate the effect of Golgiα-mannosidase II(GMII)in tumorigenesis and progression of gastric cancer.Methods : 1. Immunohistochemistry SP method was used to detemine expression of GMII,E-cadherin,Galectin-3 in gastric carcinoma(n=65) and normal gastric mucosa (n=20). 2.Western blotting assay was used to detemine expression of GMII,E-cadherin in three gastric cancer cells BGC-823, SGC-7901, MKN-28 and normal gastric epithelial cell GES-1.3. RT-PCR assay was used to detemine the mRNA expression of GMII,E-cadherin in Above four cell.Results: 1. The positive rates of GMII,E-cadherin,Galectin-3 were 85%(55/65),40%(26/65),74%(48/65),respectively,in gastric cancer ;they were 50%(10/20),100%(20/20),40%(8/20),respectively,in normal gastric mucosa.GMII,E-cadherin, Galectin-3 expression were significantly dfferent between tissues from carcinoma and normal mucosa (P <0.05 ).GMII,E-cadherin expression were significantly related to poor differentiation ,deep invasion and lymph node metastasis.GMII expression had a negative correlation with E-cadherin (P<0.05 ),and no correlation with galectin-3(p>0.05).The expression of galectin-3 was markedly related to the depth of invasion,lymph node metastasis ,but not to tumor differentiation. 2.The results of Western blotting and RT-PCR assay suggest: The relative level of GMII protein and mRNA is significantly lower in normal gastric epithelial cells than the gastric cancer cells,and the lower degree of differentiation, the higher expression, the difference was statistically significant (p <0.05). On the contrary,E-cadherin expression was highest in normal gastric epithelial cell GES-1 and the weakest in poor differentiated cell BGC-823. GMII expression had a negative correlation with E-cadherin (P<0.05 ), the difference was statistically significant.Conclusion: The expression of GMII was significantly higher in gastric cancer tissues and cells than normal gastric mucosa, suggesting that GMII may play an important role in tumorigenesis and progression of gastric cancer. There was a significant negative correlation between GMII and E-cadherin ,suggesting that GMII may progress the development of gastric carcinoma through down-regulating expression of E-cadherin.