Variations of EGF-R surface expression in squamous cell carcinomas of the head and neck region.

Background: It has been previously found that the epidermal growth factor receptor (EGF-R) is highly expressed in squamous cell carcinomas of the head and neck region (SCCHN) and that this expression correlates with malignant transformation and tumor development.

Materials And Methods: We examined 9 SCCHN cell lines and a control keratinocyte cell line for EGF-R expression, utilizing fluorescence-activated cell sorting (FACS) and Western blot analysis. Immuno-cytochemistry was performed to evaluate the receptor's cellular distribution.

Results: We found the EGF-R to be up-regulated in SCCHN. Surprisingly we did not see a clear correlation between tumor staging, grading or Stat3 signaling and EGF-R level but we observed up to three distinct EGF-R specific bands in our Western blots, implicating the presence of different protein isoforms.

Conclusion: Our data suggest that not only the amount but also the receptor function, including the presence of mutations, need to be considered in SCCHN malignancies.