title: Gene amplification of CCNE1, CCND1, and CDK6 in gastric cancers detected by multiplex ligation-dependent probe amplification and fluorescence in situ hybridization.
abstract: New and effective treatments for advanced gastric cancer are urgently needed. Cyclins E and D1 form a complex with cyclin-dependent kinase 2, 4, or 6 to regulate G1-S transition. The G1-S regulatory genes encoding cyclin E (CCNE1), cyclin D1 (CCND1), and CDK6 (CDK6) are frequently amplified in gastric cancer and may therefore influence molecularly targeted therapies against ERBB2 or EGFR when coamplified. A total of 179 formalin-fixed and paraffin-embedded gastric cancer specimens were examined for these gene amplifications by multiplex ligation-dependent probe amplification and fluorescence in situ hybridization. Amplification of at least 1 G1-S regulatory gene was found in 35 tumors (CCNE1 amplification, 15% of samples; CCND1, 6%; CDK6, 1%). In 13 of the 35 tumors, dual-color fluorescence in situ hybridization identified coamplification of the G1-S regulatory genes with ERBB2, EGFR, and/or KRAS in single cancer nuclei. The observation that cells with G1-S regulatory gene amplification contained clonal subpopulations with coamplification of ERBB2, EGFR, or KRAS in 5 early and 3 advanced cancers suggests that amplification of the G1-S regulatory genes represents an early event, which precedes ERBB2, EGFR, or KRAS amplification. Amplified CCNE1, CCND1, and CDK6 in advanced gastric cancer may be potentially useful as direct targets for molecular therapy or for combination therapy with ERBB2 or EGFR inhibitors. Multiplex ligation-dependent probe amplification could be a useful tool for identification of patients who would benefit from such therapies.
authors.affiliation: Department of Molecular and Cellular Pathology, Graduate School of Medical Science, Kanazawa University, Ishikawa 920-8641, Japan; Pathology Section, University Hospital, Kanazawa University, Ishikawa 920-8641, Japan. Electronic address: aooi@med.kanazawa-u.ac.jp.
authors.forename: Akishi
authors.initials: A
authors.lastname: Ooi
authors.affiliation: Department of Molecular and Cellular Pathology, Graduate School of Medical Science, Kanazawa University, Ishikawa 920-8641, Japan. Electronic address: takeruoyama@staff.kanazawa-u.ac.jp.
authors.forename: Takeru
authors.initials: T
authors.lastname: Oyama
authors.affiliation: Department of Molecular and Cellular Pathology, Graduate School of Medical Science, Kanazawa University, Ishikawa 920-8641, Japan. Electronic address: rnakamura@sraff.kanazawa-u.ac.jp.
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Nakamura
authors.affiliation: Department of Molecular and Cellular Pathology, Graduate School of Medical Science, Kanazawa University, Ishikawa 920-8641, Japan. Electronic address: ryosuket_tajiri@yahoo.co.jp.
authors.forename: Ryousuke
authors.initials: R
authors.lastname: Tajiri
authors.affiliation: Pathology Section, University Hospital, Kanazawa University, Ishikawa 920-8641, Japan. Electronic address: h-ikeda@med.kanazawa-u.ac.jp.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Ikeda
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Medical Science, Kanazawa University, Ishikawa 920-8641, Japan. Electronic address: fushida@staff.kanazawa-u.ac.jp.
authors.forename: Sachio
authors.initials: S
authors.lastname: Fushida
authors.affiliation: Department of Pathology, Saitama Medical Center, Jichi Medical University, Saitama 330-8503, Japan. Electronic address: ydobashi@omiya.jichi.ac.jp.
authors.forename: Yoh
authors.initials: Y
authors.lastname: Dobashi
mesh_terms: D000230:Adenocarcinoma / Q000201:enzymology / Q000235:genetics* / Q000473:pathology / Q000628:therapy; D014408:Biomarkers, Tumor / Q000235:genetics*; D001706:Biopsy; D059447:Cell Cycle Checkpoints; D049109:Cell Proliferation; D019938:Cyclin D1 / Q000235:genetics*; D019927:Cyclin E / Q000235:genetics*; D051361:Cyclin-Dependent Kinase 6 / Q000235:genetics*; D056915:DNA Copy Number Variations; D004252:DNA Mutational Analysis; D066246:ErbB Receptors / Q000235:genetics; D005784:Gene Amplification; D018628:Gene Dosage; D020022:Genetic Predisposition to Disease; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D060885:Multiplex Polymerase Chain Reaction; D009154:Mutation; D015513:Oncogene Proteins / Q000235:genetics*; D010641:Phenotype; D011237:Predictive Value of Tests; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics; D013274:Stomach Neoplasms / Q000201:enzymology / Q000235:genetics* / Q000473:pathology / Q000628:therapy
chemical_list: D014408:Biomarkers, Tumor; D019938:Cyclin D1; D019927:Cyclin E; D051361:Cyclin-Dependent Kinase 6; D066246:ErbB Receptors; D015513:Oncogene Proteins; D016283:Proto-Oncogene Proteins p21(ras); D018719:Erb-b2 Receptor Tyrosine Kinases; C530104:CCND1 protein, human; C475820:CCNE1 protein, human; C117307:KRAS protein, human; C512478:EGFR protein, human; C508053:ERBB2 protein, human; C495911:CDK6 protein, human
keywords: Cell cycle checkpoints; Gastric cancer; Gene amplification; In situ hybridization; Multiplex polymerase chain reaction