title: Automatic recognition of topic-classified relations between prostate cancer and genes using MEDLINE abstracts.
abstract: BACKGROUND
  Automatic recognition of relations between a specific disease term and its relevant genes or protein terms is an important practice of bioinformatics. Considering the utility of the results of this approach, we identified prostate cancer and gene terms with the ID tags of public biomedical databases. Moreover, considering that genetics experts will use our results, we classified them based on six topics that can be used to analyze the type of prostate cancers, genes, and their relations.
  
  
  METHODS
  We developed a maximum entropy-based named entity recognizer and a relation recognizer and applied them to a corpus-based approach. We collected prostate cancer-related abstracts from MEDLINE, and constructed an annotated corpus of gene and prostate cancer relations based on six topics by biologists. We used it to train the maximum entropy-based named entity recognizer and relation recognizer.
  
  
  RESULTS
  Topic-classified relation recognition achieved 92.1% precision for the relation (an increase of 11.0% from that obtained in a baseline experiment). For all topics, the precision was between 67.6 and 88.1%.
  
  
  CONCLUSIONS
  A series of experimental results revealed two important findings: a carefully designed relation recognition system using named entity recognition can improve the performance of relation recognition, and topic-classified relation recognition can be effectively addressed through a corpus-based approach using manual annotation and machine learning techniques.
authors.affiliation: Department of Computer Science, Graduate School of Information Science and Technology, The University of Tokyo, Tokyo, Japan. chun@is.s.u-tokyo.ac.jp
authors.forename: Hong-Woo
authors.initials: HW
authors.lastname: Chun
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Tsuruoka
authors.forename: Jin-Dong
authors.initials: JD
authors.lastname: Kim
authors.forename: Rie
authors.initials: R
authors.lastname: Shiba
authors.forename: Naoki
authors.initials: N
authors.lastname: Nagata
authors.forename: Teruyoshi
authors.initials: T
authors.lastname: Hishiki
authors.forename: Jun'ichi
authors.initials: J
authors.lastname: Tsujii
mesh_terms: D000043:Abstracting and Indexing / Q000379:methods*; D000465:Algorithms; D001185:Artificial Intelligence; D016208:Databases, Factual; D005796:Genes / Q000235:genetics; D006801:Humans; D016247:Information Storage and Retrieval / Q000379:methods*; D016239:MEDLINE; D008297:Male; D009323:Natural Language Processing; D009363:Neoplasm Proteins / Q000145:classification* / Q000235:genetics; D010506:Periodicals as Topic; D011471:Prostatic Neoplasms / Q000145:classification* / Q000235:genetics; D012660:Semantics; D012984:Software; D009626:Terminology as Topic; D018875:Vocabulary, Controlled
chemical_list: D009363:Neoplasm Proteins