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Background: Squamous cell carcinomas of the head and neck region (HNSCC) are among the most common malignancies in this area. The VX2 carcinoma of the New Zealand white rabbit metastasizes lymphatically as is the case in HNSCC and therefore, potentially, could be used as a model for HNSCC. Since the family of matrix-metalloproteinases (MMPs) is involved in the process of HNSCC invasion, the aim of this study was to investigate the expression level of MMPs and their specific inhibitors (TIMPs) in the VX2 carcinoma to evaluate if they also play a role in VX2 tumor invasion as observed in human HNSCC., Materials and Methods: The VX2 carcinoma was generated by tumor implantation in the rabbit's ear as previously described. Western blots were performed under standard conditions, utilizing antibodies against MMP-3, MMP-13, TIMP-2 and TIMP-3. Immunohistochemical staining was performed with the ABC-complex method., Results: A positive immunohistochemical signal could be detected for MMP-3, TIMP-2 and TIMP-3 with no significant signal for MMP-13. In the Western blots immunoreactive bands could be observed for MMP-3, MMP-13, TIMP-2 and TIMP-3., Conclusion: MMP-3, MMP-13, TIMP-2 and TIMP-3 were found to be expressed in VX2 carcinomas of the New Zealand white rabbits. The VX2 carcinoma therefore resembles HNSCC tumors not only in its metastatic behavior, but also regarding the expression of MMPs and TIMPs, which are the probable keyplayers during the event of invasion. These observations further underline the significance of the VX2 carcinoma as a model tumor of human HNSCC.

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.