Reliable detection of p53 aberrations in squamous cell carcinomas of the head and neck requires transcript analysis of the entire coding region.
BACKGROUND
Aberrations of the p53 tumor suppressor gene are common events in squamous cell carcinomas of the head and neck (SCCHN). However, reported frequencies range considerably, and the predictive value of aberrant p53 is continuing to be an issue of controversy. These inconsistencies are possibly caused by methodical limitations.


METHODS
In cell lines established from 23 SCCHN, we performed sequence analysis of p53 mRNA and genomic DNA, as well as protein detection using immunohistochemistry and Western blotting.


RESULTS
Of the 23 SCCHN, 21 (91%) tumors have aberrant or no p53, including four aberrations (19%) located outside the usually examined exons 5 to 9. A second allele is present in 11, and the respective transcript in 4 tumors. Expression of protein could be detected in only 12 of the 21 p53 aberrant tumors (57%).


CONCLUSIONS
Depending on the methodical approach applied, a considerable number of SCCHN may be misclassified regarding their p53 status.
Hauser
Ulrich
U
Department of Otorhinolaryngology, Head & Neck Surgery, Heinrich-Heine-University, Moorenstrasse 5, D-40225 Düsseldorf, Germany.
Balz
Vera
V
Carey
Thomas E
TE
Grénman
Reidar
R
Van Lierop
Anke
A
Scheckenbach
Kathrin
K
Bier
Henning
H
D015153:Blotting, Western; D002294:Carcinoma, Squamous Cell / Q000235:genetics*; D005629:Frozen Sections; D016158:Genes, p53 / Q000235:genetics*; D006258:Head and Neck Neoplasms / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D009154:Mutation; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017423:Sequence Analysis, RNA; D014158:Transcription, Genetic / Q000235:genetics; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000032:analysis / Q000235:genetics
D016159:Tumor Suppressor Protein p53