RNA interference-mediated simultaneous down-regulation of urokinase-type plasminogen activator receptor and cathepsin B induces caspase-8-mediated apoptosis in SNB19 human glioma cells.
The invasive character of gliomas depends on proteolytic cleavage of the surrounding extracellular matrix. Cathepsin B and urokinase-type plasminogen activator receptor (uPAR) together are known to be overexpressed in gliomas and, as such, are attractive targets for gene therapy. In the present study, we used plasmid constructs to induce the RNA interference (RNAi)-mediated down-regulation of uPAR and cathepsin B in SNB19 human glioma cells. We observed that the simultaneous down-regulation of uPAR and cathepsin B induces the up-regulation of proapoptotic genes and initiates a collapse in mitochondrial Deltapsi. Cathepsin B and uPAR down-regulated cells showed increases in the expression of activated caspase-8 and DFF40/caspase-activated DNase. Nuclear translocation of AIF and Fas ligand translocation to the cell membrane were also observed. Ki67 and X-linked inhibitor of apoptosis protein levels decreased, thereby indicating apoptosis. These results suggest the involvement of uPAR-cathepsin B complex on the cell surface and its role in maintaining the viability of SNB19 glioma cells. In conclusion, RNAi-mediated down-regulation of uPAR and cathepsin B initiates a partial extrinsic apoptotic cascade accompanied by the nuclear translocation of AIF. Our study shows the potential of RNAi-mediated down-regulation of uPAR and cathepsin B in developing new therapeutics for gliomas.
Gondi
Christopher S
CS
Program of Cancer Biology, Department of Biomedical and Therapeutic Sciences, University of Illinois College of Medicine at Peoria, One Illini Drive, Peoria, IL 61605, USA.
Kandhukuri
Neelima
N
Kondraganti
Shakuntala
S
Gujrati
Meena
M
Olivero
William C
WC
Dinh
Dzung H
DH
Rao
Jasti S
JS
D017209:Apoptosis / Q000235:genetics*; D051033:Apoptosis Inducing Factor / Q000235:genetics / Q000378:metabolism; D053181:Caspase 8 / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D002401:Cathepsin B / Q000096:biosynthesis / Q000235:genetics*; D048708:Cell Growth Processes / Q000235:genetics; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D015536:Down-Regulation; D053222:Fas Ligand Protein / Q000235:genetics / Q000378:metabolism; D016193:G1 Phase / Q000235:genetics; D015316:Genetic Therapy / Q000379:methods*; D005910:Glioma / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000235:genetics; D010718:Phosphatidylserines / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D034622:RNA Interference; D011956:Receptors, Cell Surface / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D055293:Receptors, Urokinase Plasminogen Activator; D014162:Transfection
C494829:AIFM1 protein, human; D051033:Apoptosis Inducing Factor; D053222:Fas Ligand Protein; C524898:PLAUR protein, human; D010718:Phosphatidylserines; D011956:Receptors, Cell Surface; D055293:Receptors, Urokinase Plasminogen Activator; D053181:Caspase 8; D002401:Cathepsin B