title: Evaluation of Her-2/neu gene status in osteosarcoma by fluorescence in situ hybridization and multiplex and monoplex polymerase chain reactions.
abstract: BACKGROUND
  Previous reports suggest that the human epidermal growth factor 2 (HER-2/neu) receptor may be overexpressed in osteosarcoma.
  
  
  OBJECTIVE
  To determine whether osteosarcomas have amplifications of the HER-2/neu gene.
  
  
  METHODS
  We studied a series of osteosarcomas by fluorescence in situ hybridization (FISH) and by 2 real-time polymerase chain reaction assays that measure the amount of HER-2/neu DNA relative to a control gene. The HER-2/ neu monoplex and multiplex assays were capable of identifying those cases of breast cancer that were known to overexpress HER-2/neu as assessed by FISH. We initially studied 21 cases of osteosarcoma by FISH analysis (using a technique that included a probe for chromosome 17), 11 of which had their HER-2/neu gene amplification status previously reported.
  
  
  RESULTS
  None of these osteosarcoma cases showed HER-2/neu amplification by our FISH analysis and subsequent quantitative (multiplex) polymerase chain reaction. Apparent expression of HER-2/neu protein was observed in several of the cases but the immunoreactivity was localized to the cytoplasm and was not membranous in character. An additional 35 osteosarcoma specimens were subjected to monoplex polymerase chain reaction analysis, and amplifiable DNA was recovered from 19 specimens (54%). None of these samples had HER-2/neu amplification by monoplex PCR analysis and only one case had membranous immunoreactivity graded as 1+.
  
  
  CONCLUSIONS
  Although a small subset of osteosarcomas had weak noncircumferential membranous immunoreactivity for HER-2/neu protein, no osteosarcomas demonstrated positive (2+ or 3+) immunoreactivity for HER-2/ neu protein and none showed HER-2/neu gene amplification by either FISH or polymerase chain reaction.
authors: Department of Pathology, University of Utah Health Sciences Center, Salt Lake City, UT 84132, USA.
authors: Carlynn
authors: C
authors: Willmore-Payne
authors: Joseph A
authors: JA
authors: Holden
authors: Holly
authors: H
authors: Zhou
authors: Dilip
authors: D
authors: Gupta
authors: Sharon
authors: S
authors: Hirschowitz
authors: Carl T
authors: CT
authors: Wittwer
authors: Lester J
authors: LJ
authors: Layfield