A novel CD44 v3 isoform is involved in head and neck squamous cell carcinoma progression

OBJECTIVES: CD44 comprises a family of isoforms involved in tumorigenesis, Here we investigate the role of CD44 isoforms in head and neck squamous cel l carcinoma (HNSCC) progression. MATERIALS AND METHODS: HNSCC specimens underwent reverse transcriptase-poly merase chain reaction (RT-PCR) followed by Southern blot analysis. After su rface biotinylation, FaDu (hypopharyngeal HNSCC) and CD44v3-transfected COS -7 cells were CD44 antibody-precipitated and compared by Western blot analy sis. FaDu cells underwent double immunofluorescence staining and growth ass ays. RESULTS: Southern blot analysis suggested differential CD44v3 isoform expre ssion in tumor and normal tissue. Cloning and sequencing revealed 2 novel C D44v isoforms, Western blot analysis suggested CD44v3 expression in COS-7 t ransfectants and FaDu, Double immunofluorescence staining revealed colocali zation of CD44v3 and actin in FaDu projections, Anti-CD44v3 antibody decrea sed FaDu growth. CONCLUSION: HNSCC tissue and FaDu appear to express CD44v3 isoforms, These isoforms may promote tumorigenesis. CLINICAL SIGNIFICANCE: CD44v3 isoforms may be effective tumor markers and t argets for HNSCC therapy.