Expression of the laminin gamma 2 chain in pancreatic adenocarcinoma.

Forty-two pancreatic adenocarcinomas were investigated immunohistochemically and by in situ hybridization for the expression of the laminin gamma 2 chain. In 41 cases, intracytoplasmic immunoreactivity for the gamma 2 chain was seen. Positive tumour cells were located especially at the epithelial-stromal interface of the tumour cell islands. In 22 cases, diffuse laminin gamma 2 chain immunoreactivity could also be seen in stroma and in seven cases, occasional positivity was detected in the neoplastic basement membranes. Signals for laminin gamma 2 chain mRNA in tumour cells displayed a distribution similar to that observed on immunohistochemistry. There were significantly more cases with less than 20 per cent of laminin gamma 2 chain-positive tumour cells in tumours extending to peripancreatic tissues and/or tumours with regional or distant metastases (p = 0.029). A corresponding statistical significance could also be noted in the mRNA level (P = 0.025). The results show that pancreatic adenocarcinomas display a high activity of laminin gamma 2 chain synthesis. Tumours with a strong laminin gamma 2 chain synthesis show a lower invasive and metastatic potential than tumours with a weak or moderate laminin gamma 2 chain expression.