title: Oncogenic role of p53 is suppressed by si-RNA bicistronic construct of uPA, uPAR and cathepsin-B in meningiomas both in vitro and in vivo.
abstract: Meningiomas are the most commonly occurring intracranial tumors and account for approximately 15-20% of central nervous system tumors. Patients whose tumors recur after surgery and radiation therapy have limited therapeutic options. It has also been reported recently that radiation triggers DNA repair, cell survival and cell proliferation, and reduces apoptosis via the induction of cellular protective mechanisms. Earlier studies have reported that proteases such as uPA, uPAR and cathepsin B play important roles in tumor progression. In the present study, we attempted to determine the effectiveness of two bicistronic siRNA constructs pUC (uPAR/cathepsin B) and pU2 (uPA/uPAR) either alone or in combination with radiation, both in in vitro and in vivo models. Transfection of a plasmid vector expressing double-stranded RNA for uPA, uPAR and cathepsin B significantly induced the sub-G0-G1 cell population by the mitochondrial intrinsic apoptotic pathway. Results showed that pUC efficiently enhanced sub-G0-G1 phases compared to pU2 and was more effective. Interestingly, we observed that in IOMM-Lee cell lines, combined treatment of radiation with pUC and pU2 is more effective in comparison to SF-3061 and MN cell lines. We showed that apoptosis caused by these bicistronic constructs involves Bcl-2, Bcl-xL, p53 inactivation, cytochrome c release from mitochondria and caspase-9 activation, followed by the activation of caspase-3. We also determined that apoptosis caused by pUC and pU2 involves a mechanism which includes inactivation of p53 by its translocation from nucleus to cytoplasm as confirmed by immunofluorescence, which shows the oncogenic potential of p53 in meningiomas. However, the simultaneous RNAi-mediated targeting of uPAR and cathepsin B (pUC), in combination with irradiation, has greater potential application for the treatment of human meningioma in comparison to pU2 by decreasing p53 expression both in vitro and in vivo.
authors.affiliation: Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, IL 61605 , USA.
authors.forename: Reshu
authors.initials: R
authors.lastname: Gupta
authors.forename: Venkateswara
authors.initials: V
authors.lastname: Rao Gogineni
authors.forename: Arun Kumar
authors.initials: AK
authors.lastname: Nalla
authors.forename: Chandramu
authors.initials: C
authors.lastname: Chetty
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Klopfenstein
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Tsung
authors.forename: Sanjeeva
authors.initials: S
authors.lastname: Mohanam
authors.forename: Jasti S
authors.initials: JS
authors.lastname: Rao
mesh_terms: D000818:Animals; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D020169:Caspases / Q000378:metabolism; D002401:Cathepsin B / Q000235:genetics* / Q000378:metabolism; D045744:Cell Line, Tumor; D015536:Down-Regulation; D004789:Enzyme Activation; D005260:Female; D006801:Humans; D008577:Meningeal Neoplasms / Q000378:metabolism* / Q000473:pathology; D008579:Meningioma / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics*; D055293:Receptors, Urokinase Plasminogen Activator / Q000235:genetics* / Q000378:metabolism; D014183:Transplantation, Heterologous; D047368:Tumor Burden; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*; D014568:Urokinase-Type Plasminogen Activator / Q000235:genetics* / Q000378:metabolism
chemical_list: D051017:Apoptosis Regulatory Proteins; D034741:RNA, Small Interfering; D055293:Receptors, Urokinase Plasminogen Activator; D016159:Tumor Suppressor Protein p53; D014568:Urokinase-Type Plasminogen Activator; D020169:Caspases; C533912:CTSB protein, human; D002401:Cathepsin B