title: Nimotuzumab enhances temozolomide-induced growth suppression of glioma cells expressing mutant EGFR in vivo.
abstract: A mutant form of epidermal growth factor receptor (EGFR), EGFRvIII, is common in glioblastoma (GBM) and confers enhanced tumorigenic activity and drug resistance. Nimotuzumab, an anti-EGFR antibody, has shown preclinical and clinical activity to GBM, but its specific activity against EGFRvIII has not been fully investigated. Human glioma U87MG or LNZ308 cells overexpressing either wild-type (wt) EGFR or EGFRvIII were treated with nimotuzumab, temozolomide, or both. Expression and phosphorylation status of molecules were determined by Western blot analysis. Methylation status of promoter region of O(6) -methylguanine-DNA methyltransferase (MGMT) was detected by methylation-specific PCR. Antitumor activity was tested using nude mice bearing either subcutaneous or intracerebral xenografts along with analyses of EGFR phosphorylation status, proliferation, apoptosis, and vessel density. Nimotuzumab treatment resulted in reduction of EGFRvIII tyrosine phosphorylation with a decrease in Akt phosphorylation that was greater than that of wtEGFR. Correspondingly, antitumor effects, growth suppression and survival elongation, were more significant in mice bearing either subcutaneous or intracerebral tumor expressing EGFRvIII than in those expressing wtEGFR. These effects were markedly increased when temozolomide was combined with nimotuzumab. The post-treatment recurrent brain tumors exhibited a decrease in expression of the mismatch repair (MMR) proteins, MSH6 and MLH1, but their methylated MGMT status did not changed. Nimotuzumab has in vivo antitumor activity against GBM, especially those expressing EGFRvIII, when combined with temozolomide. This could provide a basis for preselection of patients with GBM by EGFR status who might benefit from the nimotuzumab and temozolomide combination therapy.
authors.affiliation: Department of Neurosurgery, Kugayama Hospital, 2-14-20 Kitakarasuyama, Setagaya, Tokyo, 157-0061, Japan.|Department of Neurosurgery, Kyorin University Faculty of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo, 181-8611, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Nitta
authors.affiliation: Department of Neurosurgery, Kyorin University Faculty of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo, 181-8611, Japan.
authors.forename: Saki
authors.initials: S
authors.lastname: Shimizu
authors.affiliation: Department of Pathology, Kyorin University Faculty of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo, 181-8611, Japan.|Department of Anatomic Pathology, Tokyo Medical University, 6-7-1 Nishi-Shinjuku, Shinjuku, Tokyo, 160-0023, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Shishido-Hara
authors.affiliation: Department of Neurosurgery, Kyorin University Faculty of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo, 181-8611, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Suzuki
authors.affiliation: Department of Neurosurgery, Kyorin University Faculty of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo, 181-8611, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Shiokawa
authors.affiliation: Department of Neurosurgery, Kyorin University Faculty of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo, 181-8611, Japan.
authors.forename: Motoo
authors.initials: M
authors.lastname: Nagane
mesh_terms: D000818:Animals; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage* / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000494:pharmacology; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D019175:DNA Methylation / Q000187:drug effects; D015254:DNA Modification Methylases / Q000235:genetics; D045643:DNA Repair Enzymes / Q000235:genetics; D003606:Dacarbazine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D004357:Drug Synergism; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D005910:Glioma / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D051379:Mice; D009154:Mutation; D015398:Signal Transduction / Q000187:drug effects; D000077204:Temozolomide; D025521:Tumor Suppressor Proteins / Q000235:genetics; D023041:Xenograft Model Antitumor Assays
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D025521:Tumor Suppressor Proteins; C501466:nimotuzumab; D003606:Dacarbazine; D015254:DNA Modification Methylases; C515491:MGMT protein, human; C512478:EGFR protein, human; D066246:ErbB Receptors; D045643:DNA Repair Enzymes; D000077204:Temozolomide
keywords: Drug resistance; EGFRvIII; MSH6; glioblastoma; nimotuzumab; temozolomide