title: Humanized chondroitinase ABC sensitizes glioblastoma cells to temozolomide.
abstract: BACKGROUND
  Malignant gliomas (glioblastomas; GBMs) are extremely aggressive and have a median survival of approximately 15 months. Current treatment modalities, which include surgical resection, radiation and chemotherapy, have done little to prolong the lives of GBM patients. Chondroitin sulfate proteoglycans (CSPG) are critical for cell-cell and cell-extracellular matrix (ECM) interactions and are implicated in glioma growth and invasion. Chondroitinase (Chase) ABC is a bacterial enzyme that cleaves chondroitin sulfate disaccharide chains from CSPGs in the tumor ECM. Wild-type Chase ABC has limited stability and/or activity in mammalian cells; therefore, we created a mutant humanized version (Chase M) with enhanced function in mammalian cells.
  
  
  METHODS
  We hypothesized that disruption of cell-cell and cell-ECM interactions by ChaseM and temozolomide (TMZ) will enhance the chemotherapeutic availability and sensitivity of glioma cells.
  
  
  RESULTS
  Utilizing primary patient-derived neurospheres, we found that ChaseM decreases glioma neurosphere aggregation in vitro. Furthermore, an oncolytic HSV-1 virus expressing secreted ChaseM (OV-ChaseM) enhanced viral spread and glioma cell killing compared to OV-Control, in vitro. OV-ChaseM plus TMZ combinatorial treatment resulted in a significant synergistic enhancement of glioma cell killing accompanied by an increase in apoptotic cell death. Intracellular flow cytometric analysis revealed a significant reduction in the phosphorylation of the pro-survival AKT protein following OV-ChaseM plus TMZ treatment. Lastly, in nude mice bearing intracranial GBM30 glioma xenografts, intratumoral OV-ChaseM plus TMZ (10 mg/kg by oral gavage) combination therapy resulted in a significant (p < 0.02) enhancement of survival compared to each individual treatment alone.
  
  
  CONCLUSIONS
  These data reveal that OV-ChaseM enhances glioma cell viral susceptibility and sensitivity to TMZ.
authors.affiliation: Department of Neurological Surgery, The Ohio State University Comprehensive Cancer Center, The James Cancer Hospital, and Solove Research Institute, Columbus, OH, USA.
authors.forename: Alena Cristina
authors.initials: AC
authors.lastname: Jaime-Ramirez
authors.affiliation: Department of Neurological Surgery, The Ohio State University Comprehensive Cancer Center, The James Cancer Hospital, and Solove Research Institute, Columbus, OH, USA.
authors.forename: Nina
authors.initials: N
authors.lastname: Dmitrieva
authors.affiliation: Department of Neurological Surgery, The Ohio State University Comprehensive Cancer Center, The James Cancer Hospital, and Solove Research Institute, Columbus, OH, USA.
authors.forename: Ji Young
authors.initials: JY
authors.lastname: Yoo
authors.affiliation: Department of Neurological Surgery, The Ohio State University Comprehensive Cancer Center, The James Cancer Hospital, and Solove Research Institute, Columbus, OH, USA.
authors.forename: Yeshavanth
authors.initials: Y
authors.lastname: Banasavadi-Siddegowda
authors.affiliation: Center for Biostatistics Biomedical Informatics Department, The Ohio State University Comprehensive Cancer Center, The James Cancer Hospital, and Solove Research Institute, Columbus, OH, USA.
authors.forename: Jianying
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Neuroscience Graduate Program and The Medical Scientist Training Program, The Ohio State University Comprehensive Cancer Center, The James Cancer Hospital, and Solove Research Institute, Columbus, OH, USA.
authors.forename: Theresa
authors.initials: T
authors.lastname: Relation
authors.affiliation: Department of Neurological Surgery, The Ohio State University Comprehensive Cancer Center, The James Cancer Hospital, and Solove Research Institute, Columbus, OH, USA.
authors.forename: Chelsea
authors.initials: C
authors.lastname: Bolyard
authors.affiliation: Department of Neurological Surgery, The Ohio State University Comprehensive Cancer Center, The James Cancer Hospital, and Solove Research Institute, Columbus, OH, USA.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Wojton
authors.affiliation: Department of Neurological Surgery, The Ohio State University Comprehensive Cancer Center, The James Cancer Hospital, and Solove Research Institute, Columbus, OH, USA.
authors.forename: Balveen
authors.initials: B
authors.lastname: Kaur
mesh_terms: D000483:Alleles; D019943:Amino Acid Substitution; D000818:Animals; D018906:Antineoplastic Agents, Alkylating / Q000494:pharmacology*; D017209:Apoptosis / Q000235:genetics; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000235:genetics; D002522:Chlorocebus aethiops; D019765:Chondroitin ABC Lyase / Q000235:genetics* / Q000378:metabolism; D003606:Dacarbazine / Q000031:analogs & derivatives* / Q000494:pharmacology; D004195:Disease Models, Animal; D019008:Drug Resistance, Neoplasm / Q000187:drug effects* / Q000235:genetics*; D004789:Enzyme Activation; D015870:Gene Expression; D005822:Genetic Vectors / Q000235:genetics; D005909:Glioblastoma / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D018259:Herpesvirus 1, Human / Q000235:genetics; D006801:Humans; D051379:Mice; D009154:Mutation; D050130:Oncolytic Virotherapy; D000077204:Temozolomide; D014161:Transduction, Genetic; D016896:Treatment Outcome; D047368:Tumor Burden; D014407:Tumor Cells, Cultured; D014709:Vero Cells; D023041:Xenograft Model Antitumor Assays
chemical_list: D018906:Antineoplastic Agents, Alkylating; D003606:Dacarbazine; D019765:Chondroitin ABC Lyase; D000077204:Temozolomide
keywords: HSV; animal model; brain cancer; chemotherapy; gene delivery; oncolytic viruses; tumor biology