title: Beta class II tubulin predominates in normal and tumor breast tissues.
abstract: BACKGROUND
  Antimitotic chemotherapeutic agents target tubulin, the major protein in mitotic spindles. Tubulin isotype composition is thought to be both diagnostic of tumor progression and a determinant of the cellular response to chemotherapy. This implies that there is a difference in isotype composition between normal and tumor tissues.
  
  
  METHODS
  To determine whether such a difference occurs in breast tissues, total tubulin was fractionated from lysates of paired normal and tumor breast tissues, and the amounts of beta-tubulin classes I + IV, II, and III were measured by competitive enzyme-linked immunosorbent assay (ELISA). Only primary tumor tissues, before chemotherapy, were examined. Her2/neu protein amplification occurs in about 30% of breast tumors and is considered a marker for poor prognosis. To gain insight into whether tubulin isotype levels might be correlated with prognosis, ELISAs were used to quantify Her2/neu protein levels in these tissues.
  
  
  RESULTS
  Beta-tubulin isotype distributions in normal and tumor breast tissues were similar. The most abundant beta-tubulin isotypes in these tissues were beta-tubulin classes II and I + IV. Her2/neu levels in tumor tissues were 5-30-fold those in normal tissues, although there was no correlation between the Her2/neu biomarker and tubulin isotype levels.
  
  
  CONCLUSIONS
  These results suggest that tubulin isotype levels, alone or in combination with Her2/neu protein levels, might not be diagnostic of tumorigenesis in breast cancer. However, the presence of a broad distribution of these tubulin isotypes (for example, 40-75% beta-tubulin class II) in breast tissue, in conjunction with other factors, might still be relevant to disease progression and cellular response to antimitotic drugs.
authors.affiliation: School of Medicine, University of Mississippi Medical Center, Jackson, Mississippi, USA.
authors.forename: James H
authors.initials: JH
authors.lastname: Dozier
authors.forename: Laree
authors.initials: L
authors.lastname: Hiser
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Davis
authors.forename: Nancy Stubbs
authors.initials: NS
authors.lastname: Thomas
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Tucci
authors.forename: Hamed A
authors.initials: HA
authors.lastname: Benghuzzi
authors.forename: Anthony
authors.initials: A
authors.lastname: Frankfurter
authors.forename: John J
authors.initials: JJ
authors.lastname: Correia
authors.forename: Sharon
authors.initials: S
authors.lastname: Lobert
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism; D001940:Breast / Q000737:chemistry*; D001943:Breast Neoplasms / Q000737:chemistry* / Q000473:pathology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D020033:Protein Isoforms / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012334:RNA, Neoplasm / Q000378:metabolism; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013552:Swine; D014404:Tubulin / Q000096:biosynthesis / Q000378:metabolism*; D014407:Tumor Cells, Cultured
chemical_list: D020033:Protein Isoforms; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D018719:Erb-b2 Receptor Tyrosine Kinases; D014404:Tubulin