Alteration of Integrins by Interleukin-1α in Human Pancreatic Cancer Cells

Abstract

Introduction Adhesion of tumor cells to extracellular matrix (ECM) proteins plays an important role in tumor invasion and metastasis. Aims To investigate the expression of integrins in human pancreatic cancer cell lines and its alteration by interleukin (IL)-1α to examine the mechanism of adhesion of metastatic human pancreatic cancer cells to ECM proteins. Methodology The expression of integrin subunits and their alteration by IL-1α were examined by flow-cytometric analysis and cellular enzyme-linked immunosorbent assay in three metastatic human pancreatic cancer cell lines (AsPC-1, BxPC-3, and SW1990) and two nonmetastatic cancer cell lines (PaCa-2 and PANC-1). In addition, assays of cancer cell adhesion to ECM proteins were performed to investigate if increased integrin expression actually affected the adhesive interaction between cancer cells and the putative integrin ECM ligands. Results The α 6 subunit expressed in metastatic cancer cells was enhanced by IL-1α. Metastatic cancer cells also showed preferential adherence to laminin compared with nonmetastatic cancer cells, and this was enhanced by IL-1α. Conclusion In pancreatic cancer, the enhancement of α 6 β 1 integrin by IL-1α through IL-1 receptor type I, as well as the expression of α 6 β 1 integrin, plays an important role in metastasis formation.