IN-VITRO INHIBITION OF HUMAN GLIOBLASTOMA CELL-LINE INVASIVENESS BY ANTISENSE UPA RECEPTOR

The cell surface urokinase-type plasminogen activator receptor (uPAR) has been shown to be a key molecule in regulating plasminogen-mediated extracellular proteolysis, To investigate the role of uPAR in invasio n of brain tumors, human glioblastoma cell line SNB19 was stably trans fected with a vector capable of expressing an antisense transcript com plementary to the 300 base pair of the 5' end of the uPAR mRNA, Parent al and stably transfected (vector, sense, and antisense) cell lines we re analysed for uPAR mRNA transcript by Northern blot analysis, and re ceptor protein levels were measured by radioreceptor assays and Wester n blotting. Significant reduction of uPAR sites was observed in the an tisense transfected cell lines, The levels of uPAR mRNA were significa ntly decreased in antisense clones compared to control, vector and sen se clones, The invasive potential of the cell lines in vitro was measu red by Matrigel invasion assay and migration of cells from spheroids t o monolayers. The antisense transfected cells showed a markedly lower level of invasion and migration than the controls, The antisense clone s were more adhesive to the ECM components compared to parental, vecto r and sense clones, All transfected (vector, sense and antisense) clon es and parental cells produced similar levels of uPA activity without any significant difference however, MMP-2 activity was decreased in an tisense clones compared to controls, These results demonstrate that uP AR expression is critical for the invasiveness of human gliomas and do wn regulation of uPAR expression may be a feasible approach to decreas e invasiveness.