Significance Of ZO-1 Different Domains In The Gastric Carcinoma

[Background and objective] Gastric cancer is one of the most common malignancies worldwide. China is one of the highest incidence regions. ZO-1 gene was identified which was related to carcinogenesis and progression. Our laboratory early RT-PCR results show that ZO-1α+ mRNA is equal in cancer and normal tissue of GC,but immunohistochemical study has found that the change of ZO-1 protein localization is involved in gastric carcinoma advancing,that showed aberrant expression of ZO-1 from membranous expression changed to cytoplasmic expression. ZO-1 contains three PDZ domains,a SH3 domain,a GUK domain,a ABR domain,a ZU5 domain and a alpha motif. To further investigate the role of ZO-1 different domains in advanced gastric carcinoma,we choose ZO-1(α-pan)(It is raised against PDZ3 domain,SH3 domain,GUK domain and alpha motif),ZO-1(α+)(It is raised against alpha motif),ZO-1(α-)(It is raised against ten residues at the splice junction ) and ZO-1 ( H-300 )( It is raised against ZU5 domain).Immunohistochemical staining with them to study relationship between expression of ZO-1 different domains and the function of ZO-1 different domains in GC.[Methods] 199 cases of archival paraffin-embedded gastric cancer tissues from the First Affiliated Hospital of Fujian Medical University from November 2008 to June 2009. Selecting five representative sites to make tissue microarray, which contain normal gastric mucosa, cancer tissue of mucosa layer, the central area of carcinoma, invasive front of carcinoma and metastatic area of lymph node. Immunohistochemistry was performed to detect the expression of ZO-1(α?pan),ZO-1(α+),ZO-1(α-)and ZO-1(ZU5).[Results]1. In contrast to adjaeent noneoplastic mucosa, most adenocarcinoma showed aberrant expression of ZO-1(α-pan), ZO-1(α+)and ZO-1(ZU5)which away from membrane and locate in cytoplasm or negtive. 2. The aberrant expression of ZO-1(α-pan), ZO-1(α+)and ZO-1(ZU5)in the central area of carcinoma more than which in mucosa layer and less than invasive front of carcinoma,which in metastatic area of lymph node less than in the invasive front of carcinoma.3. The aberrant expression of ZO-1(α-pan), ZO-1(α+)and ZO-1(ZU5)in advanced gastric carcinoma more severe than in early gastric carcinoma.4. The aberrant expression of ZO-1(α-pan), ZO-1(α+)and ZO-1(ZU5)was significant different involve Lauren classification. ZO-1(ZU5)was significant different involve age.5. Analyzing the expression level of ZO-1(α-pan), ZO-1(α+)and ZO-1(ZU5)in the cancer tissue of mucosa layer find significant difference between ZO-1(α+)and ZO-1(ZU5),and also between ZO-1(α-pan)and ZO-1(ZU5).6. Analyzing the expression level of ZO-1(α-pan), ZO-1(α+)and ZO-1(ZU5)in the central area of advanced gastric carcinoma find significant difference between ZO-1(α-pan)and ZO-1(ZU5).7. Analyzing expression level of ZO-1(α-pan), ZO-1(α+)and ZO-1(ZU5) in the metastatic area of lymph node find significant difference between ZO-1(α+)and ZO-1(ZU5),and also between ZO-1(α-pan)and ZO-1(ZU5).8. The expression level of ZO-1(α-pan), ZO-1(α+)and ZO-1(ZU5)have no obvious correlation in the normal gastric mucosa,but which have obvious correlation in gastric cancer tissues.9. Pre-test using a variety of kits to detect ZO-1(α-)which from guinea pig,but all in vain,so we cancel the immunohistochemistry of it.[Conclusions]1. Most adenocarcinoma in mucosa layer showed aberrant expression of ZO-1(α-pan), ZO-1(α+)and ZO-1(ZU5)which away from membrane and locate in cytoplasm or negtive, which suggest that ZO-1 PDZ3 domain,GUK domain,SH3 domain, ZU5 domain and alpha motif might be involved in the incidence of gastric cancer.2. The aberrant expression of ZO-1(α-pan), ZO-1(α+)and ZO-1(ZU5),which in the central area of carcinoma more than which in cancer tissue of mucosa layer and less than the invasive front of carcinoma, which suggest that ZO-1 PDZ3 domain,GUK domain, SH3 domain, ZU5 domain and alpha motif might be involved in EMT.3. The aberrant expression of ZO-1(α-pan), ZO-1(α+)and ZO-1(ZU5), which in metastatic area of lymph node less than in the invasive front of carcinoma, which suggest that ZO-1 PDZ3 domain,GUK domain, SH3 domain, ZU5 domain and alpha motif might be involved in MET.4. The aberrant expression of ZO-1(α-pan), ZO-1(α+)and ZO-1(ZU5)in advanced gastric carcinoma more severe than in early gastric carcinoma, which suggest that ZO-1 PDZ3 domain,GUK domain, SH3 domain, ZU5 domain and alpha motif might be involved in gastric cancer advancing.5. The aberrant expression of ZO-1(α-pan), ZO-1(α+)and ZO-1(ZU5)was significant different involve Lauren classification,which suggest that ZO-1 PDZ3 domain,GUK domain, SH3 domain, ZU5 domain and alpha motif is involved in maintaining of GC phenotype.6. Significant difference between ZO-1(α+)and ZO-1(ZU5) and between ZO-1(α-pan)and ZO-1(ZU5) in cancer tissue of mucosa layer and metastatic area of lymph node, which suggest there have disruption between ZU5 domain and alpha motif.7. Significant difference between ZO-1(α-pan)and ZO-1(ZU5) in the central area of the carcinoma, which suggest there have disruption between PDZ3 domain and ZU5 domain.