Analysis of invasion-metastasis in pancreatic cancer: Correlation between the expression and arrangement of tight junction protein-2 and cell dissociation in pancreatic cancer cells.

High frequency of invasion and metastasis is one of the key characteristics of pancreatic cancer. In our recent study, tight junction protein-2 (Tjp-2) was identified as a differentially expressed gene related to invasion-metastasis in highly (PC-1.0) and weakly (PC-1) invasive and metastatic pancreatic cancer cells by cDNA microarray analysis. Changes in the structure and function of tight junctions are correlated with carcinogenesis and tumour development. In this study, RT-PCR, Western blotting and immunocytochemistry were used to study the correlation between the expression and localisation of Tjp-2 and cell dissociation in pancreatic cancer. Tjp-2 mRNA and protein were differentially expressed in PC-1.0 and PC-1 cells. Furthermore, the addition of dissociation factor (DF) or U0126 (a MEK inhibitor) significantly induced changes in the mRNA expression and protein intracellular localisation of Tjp-2, and in the simultaneous cell dissociation of PC-1.0 and PC-1 cells. However, protein expression of Tjp-2 was not affected by DF or U0126 treatment. The current results indicate that Tjp-2 is involved in the regulation of cell dissociation in pancreatic cancer cells through changes in gene expression and intracellular localisation. Tjp-2 may serve as a new target for molecular therapies that prevent the invasion and metastasis of pancreatic cancer.