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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Blotting, Southern, Blotting, Western, Carcinoma, Squamous Cell, DNA Primers, Disease Progression, Fluorescent Antibody Technique, Head and Neck Neoplasms, Humans, Hyaluronan Receptors, Protein Isoforms, Reverse Transcriptase Polymerase Chain Reaction, Tumor Cells, Cultured.
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Is a novel CD44 v3 isoform involved in head and neck squamous cell carcinoma progression? Context: CD44 comprises a family of isoforms involved in tumorigenesis. Here we investigate the role of CD44 isoforms in head and neck squamous cell carcinoma (HNSCC) progression. HNSCC specimens underwent reverse transcriptase-polymerase chain reaction (RT-PCR) followed by Southern blot analysis. After surface biotinylation, FaDu (hypopharyngeal HNSCC) and CD44v3-transfected COS-7 cells were CD44 antibody-precipitated and compared by Western blot analysis. FaDu cells underwent double immunofluorescence staining and growth assays. Southern blot analysis suggested differential CD44v3 isoform expression in tumor and normal tissue. Cloning and sequencing revealed 2 novel CD44v isoforms. Western blot analysis suggested CD44v3 expression in COS-7 transfectants and FaDu. Double immunofluorescence staining revealed co-localization of CD44v3 and actin in FaDu projections. Anti-CD44v3 antibody decreased FaDu growth.
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HNSCC tissue and FaDu appear to express CD44v3 isoforms. These isoforms may promote tumorigenesis. Final Decision: yes