title: Inhibition of Y-box binding protein-1 slows the growth of glioblastoma multiforme and sensitizes to temozolomide independent O6-methylguanine-DNA methyltransferase.
abstract: Glioblastoma multiforme (GBM) is an aggressive type of brain tumor where <3% of newly diagnosed cases in the patients will survive >5 years. In adults, GBM is the most common type of brain tumor. It is rarer in children, where it constitutes approximately 15% of all brain tumors diagnosed. These tumors are often invasive, making surgical resection difficult. Further, they can be refractory to current therapies such as temozolomide. The current dogma is that temozolomide resistance rests on the expression of O6-methylguanine-DNA methyltransferase (MGMT) because it cleaves methylated DNA adducts formed by the drug. Our laboratory recently reported that another drug resistance gene known as the Y-box binding protein-1 (YB-1) is highly expressed in primary GBM but not in normal brain tissues based on the evaluation of primary tumors. We therefore questioned whether GBM depend on YB-1 for growth and/or response to temozolomide. Herein, we report that YB-1 inhibition reduced tumor cell invasion and growth in monolayer as well as in soft agar. Moreover, blocking this protein ultimately delayed tumor onset in mice. Importantly, inhibiting YB-1 enhanced temozolomide sensitivity in a manner that was independent of MGMT in models of adult and pediatric GBM. In conclusion, inhibiting YB-1 may be a novel way to improve the treatment of GBM.
authors.affiliation: Department of Pediatrics, Child and Family Research Institute, University of British Columbia, 950 West 28th Avenue, Vancouver, British Columbia, Canada V5Z 4H4.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Gao
authors.forename: Abbas
authors.initials: A
authors.lastname: Fotovati
authors.forename: Cathy
authors.initials: C
authors.lastname: Lee
authors.forename: Michelle
authors.initials: M
authors.lastname: Wang
authors.forename: Gilbert
authors.initials: G
authors.lastname: Cote
authors.forename: Emma
authors.initials: E
authors.lastname: Guns
authors.forename: Brian
authors.initials: B
authors.lastname: Toyota
authors.forename: Damien
authors.initials: D
authors.lastname: Faury
authors.forename: Nada
authors.initials: N
authors.lastname: Jabado
authors.forename: Sandra E
authors.initials: SE
authors.lastname: Dunn
mesh_terms: D000328:Adult; D000818:Animals; D018906:Antineoplastic Agents, Alkylating / Q000494:pharmacology; D001932:Brain Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000473:pathology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002648:Child; D016000:Cluster Analysis; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D003606:Dacarbazine / Q000031:analogs & derivatives* / Q000494:pharmacology; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D005909:Glioblastoma / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D006801:Humans; D015151:Immunoblotting; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009374:Neoplasms, Experimental / Q000188:drug therapy / Q000235:genetics / Q000473:pathology; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D019853:O(6)-Methylguanine-DNA Methyltransferase / Q000378:metabolism; D034622:RNA Interference; D000077204:Temozolomide; D014183:Transplantation, Heterologous; D047368:Tumor Burden / Q000187:drug effects; D051840:Y-Box-Binding Protein 1
chemical_list: D018906:Antineoplastic Agents, Alkylating; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D051840:Y-Box-Binding Protein 1; C070856:YBX1 protein, human; D003606:Dacarbazine; D019853:O(6)-Methylguanine-DNA Methyltransferase; D000077204:Temozolomide