Expression and localization profile of tenascin in squamous cell carcinomas of the head and neck

Tenascin is a glycoprotein of the extracellular matrix and is mainly expres sed in association with a high proliferative and migratory activity. This c haracteristic has made it a successfully used target molecule in the treatm ent of glioblastoma. An application of anti-tenascin therapy concept in squ amous cell carcinomas of the head and neck (HNSCC) mainly depends on the ex pression pattern of tenascin ina tumor type. In the present study, we analy zed the messenger (m) RNA and protein expression of tenascin in HNSCC tumor s when compared to normal mucosa and determined its cellular localization a nd correlation with various clinical parameters, including tumor staging. I n native tissue tenascin protein was localized in the entire extracellular matrix surrounding the tumor. Normal mucosa showed only a weak and interrup ted basement membrane staining, in situ hybridization revealed a very faint tenascin mRNA signal in basal cells of normal mucosa and a strong signal i n tumor cells. This tumor cell specific expression of tenascin was confirme d at the protein level in HNSCC cultures. However, there was no correlation of tenascin expression with tumor staging or tumor cell proliferation. Our data clearly show that tenascin is selectively expressed in HNSCC and ther efore could be useful fora therapeutic intervention in these tumors.