Expression of αv Integrin Family in Gastric Carcinomas: Increased αvβ6 is Associated with Lymph Node Metastasis
To investigate the alterations as to integrin expression in human gastric carcinomas, we analyzed the av subunit and 5 types of β subunits using reverse transcription-polymerase chain reaction (RT-PCR) and competitive RT-PCR. The incidence of αv, β6 and β8 expression was significantly higher in carcinoma tissues than in non-neoplastic gastric mucosal tissues (NGMTs). Out of 18 carcinoma cases with coexpression of αv and β6 subunits, which was demonstrated by RT-PCR, 17 cases (94%) showed lymph node metastasis (p = 0.0033). This tendency was confirmed by immunohistochemistry; most cases (23/28, 82%) in which αvβ6 integrin was immunohistochemically detected showed lymph node metastasis (p = 0.0193). RT-PCR and immunohistochemical studies showed that gastric carcinoma tissues expressed β5 subunit in all cases. Furthermore, in a quantitative analysis using competitive RT-PCR, the mean level of β5 expression was approximately 140 times higher in gastric carcinomas than in NGMTs. Most gastric carcinoma cases (27/38, 71%) were immunohistochemically positive for β8 subunit. These findings suggest that some members of the αv integrin family (αvβ5, αvβ6, αvβ8) are up-regulated, and that αvβ6 integrin may be involved in the lymphatic metastasis of gastric carcinomas.
Document Type: Original Article
Affiliations: 1: Department of Molecular and Cellular Pathology, Kanazawa University, Kanazawa, Japan 2: Department of Molecular Genetics of Cardiovascular Disorders, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan 3: Division of Diagnostic Molecular Oncology, Cancer Research Institute, Kanazawa University, Kanazawa, Japan
Publication date: April 1, 2003