title: Metabolic targeting of lactate efflux by malignant glioma inhibits invasiveness and induces necrosis: an in vivo study.
abstract: Glioblastoma multiforme (GBM) are the most malignant among brain tumors. They are frequently refractory to chemotherapy and radiotherapy with mean patient survival of approximately 6 months, despite surgical intervention. The highly glycolytic nature of glioblastomas describes their propensity to metabolize glucose to lactic acid at an elevated rate. To survive, GBMs efflux lactic acid to the tumor microenvironment through transmembrane transporters denoted monocarboxylate transporters (MCTs). We hypothesized that inhibition of MCT function would impair the glycolytic metabolism and affect both glioma invasiveness and survival. We examined the effect on invasiveness with α-cyano-4-hydroxy-cinnamic acid (ACCA, 4CIN, CHCA), a small-molecule inhibitor of lactate transport, through Matrigel-based and organotypic (brain) slice culture invasive assays using U87-MG and U251-MG glioma cells. We then conducted studies in immunodeficient rats by stereotaxic intracranial implantation of the glioma cells followed by programmed orthotopic application of ACCA through osmotic pumps. Effect on the implanted tumor was monitored by small-animal magnetic resonance imaging. Our assays indicated that glioma invasion was markedly impaired when lactate efflux was inhibited. Convection-enhanced delivery of inhibitor to the tumor bed caused tumor necrosis, with 50% of the animals surviving beyond the experimental end points (3 months after inhibitor exhaustion). Most importantly, control animals did not display any adverse neurologic effects during orthotopic administration of ACCA to brain through programmed delivery. These results indicate the clinical potential of targeting lactate efflux in glioma through delivery of small-molecule inhibitors of MCTs either to the tumor bed or to the postsurgical resection cavity.
authors.affiliation: Department of Neurological Surgery, Wayne State University School of Medicine, Detroit, MI 48201, USA.
authors.forename: Chaim B
authors.initials: CB
authors.lastname: Colen
authors.forename: Yimin
authors.initials: Y
authors.lastname: Shen
authors.forename: Farhad
authors.initials: F
authors.lastname: Ghoddoussi
authors.forename: Pingyang
authors.initials: P
authors.lastname: Yu
authors.forename: Todd B
authors.initials: TB
authors.lastname: Francis
authors.forename: Brandon J
authors.initials: BJ
authors.lastname: Koch
authors.forename: Michael D
authors.initials: MD
authors.lastname: Monterey
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Galloway
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Sloan
authors.forename: Saroj P
authors.initials: SP
authors.lastname: Mathupala
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001692:Biological Transport / Q000187:drug effects; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D003373:Coumaric Acids / Q000627:therapeutic use*; D004195:Disease Models, Animal; D015536:Down-Regulation / Q000187:drug effects; D005910:Glioma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D019344:Lactic Acid / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008297:Male; D058990:Molecular Targeted Therapy; D009336:Necrosis / Q000378:metabolism; D009361:Neoplasm Invasiveness; D051381:Rats; D011923:Rats, Nude; D014183:Transplantation, Heterologous; D015854:Up-Regulation; D023041:Xenograft Model Antitumor Assays
chemical_list: D000970:Antineoplastic Agents; D003373:Coumaric Acids; C007175:alpha-cyano-4-hydroxycinnamate; D019344:Lactic Acid