Establishment of inflammatory and malignant tumor disease model mice based on abnormalities in adhesiveness of immune cells and its clinical application.

点击翻译按钮获取中文摘要

In this study we found that in mouse pro-B cell line, BAF-B03 cells, an active form of H-Ras activates α_4 and α_6 integrins, thereby enhancing cell adhesiveness to fibronectin and laminin. It was also found that functional cooperation of an active form of H-Ras and c-Myc results in the activation of α_4 integrin, the induction of VCAM-1, a counter-receptor for VLA-4 (α_4β_1), and in the down-regulation of α_6a integrin, leading to homophilic cell aggregation and to a loss of cell adhesiveness to laminin. Furthermore, it was shown that BAF-B03 cells constitutively expressing an active form of H-Ras and c-Myc form tumor and exhibit invasion and metastasis when injected into nude mice. Loss of laminin binding of BAF-B03 cells expressing active H-Ras and c-Myc may contribute to infiltration of tumor cells from primary nodules. It would be of interest to examine whether or not functional cooperation of H-Ras and c-Myc in regulating the expression and/or activity of cell adhesion molecules is cell-type specific. In this study, we also showed that synovial cells from patients of Rheumatoid Arthritis (RA) can be separated into two functionally distinct subsets on the basis of the expression levels of ICAM-1. ICAM-1-positive cells exhibit cell cycle arrest and undergo apoptosis, while ICAM-1-negative cells proliferate efficiently and continuously. It is assumed that ICAM-1-negative synovial cells in RA patients can be an important therapeutic target.