DIFFERENTIAL EXPRESSION OF LAMININ RECEPTORS IN HUMAN HEPATOCELLULAR-CARCINOMA

Background-Laminin receptors are involved in cell-extracellular matrix interactions in malignant cells that show invasion and metastasis. He patocellular carcinoma frequently shows early invasion into blood vess els, and intrahepatic and extrahepatic metastases. However, the role o f laminin receptors in hepatocellular carcinoma is unknown. Aims-To ex amine the expression of mRNA for laminin receptors and their isoforms in hepatocellular carcinoma. Methods-The expression of several laminin receptors, including al integrin, alpha 6 integrin and its isoforms a lpha 6A and alpha 6B, beta 1 integrin and its isoforms beta 1A and bet a 1B, and 32kD/67kDa laminin binding protein was examined in human hep atocellular carcinomas and non-cancerous liver tissues using the rever se transcription polymerase chain reaction. Results-alpha 6 Integrin, beta 1 integrin, and laminin binding protein showed notably increased expression in hepatocellular carcinoma, compared with non-cancerous li ver tissue, although the alpha 1 integrin did not show a significant c hange. Furthermore, beta 1B integrin, a splicing variant of beta 1 int egrin, was overexpressed in hepatocellular carcinoma while the PLA int egrin isoform did not show significant changes between hepatocellular carcinoma and surrounding non-cancerous liver tissue. Conclusions-The differential upregulation of laminin receptors and their splicing isof orms was shown in hepatocellular carcinoma, suggesting that certain la minin receptors and their isoforms may be involved in the development and progression of hepatocellular carcinoma.