Brief Summary: RATIONALE: Studying proteins in head and neck cancer cells in the laboratory may help doctors learn more about changes that occur in DNA and identify biomarkers related to cancer. PURPOSE: This laboratory study is looking at proteins in head and neck cancer cells.

Detailed Description: OBJECTIVES: * Define the function and mechanism of LZAP in regulating ARF. * Determine the mechanism and biological consequences of LZAP inhibition of NF-κB. * Determine if LZAP has tumor suppressor activity by conditional targeting of LZAP in mice. OUTLINE: Using molecular laboratory techniques, this study examines the biochemical mechanisms by which LZAP activates transcriptional, tumor suppressive activity (both p53-dependent and p53-independent) of ARF and inhibits transcriptional, tumorigenic activity of NF-kB. LZAP regulation of newly identified ARF activities, such as S-phase delay and ARF-mediated B23 degradation are also evaluated. LZAP's tumor suppressive activity is assessed in vivo using a conditional knockout vector to target LZAP in mice and to observe for spontaneous and induced tumor formation. Laboratory analyses used to determine study endpoints include standard recombinant DNA, recombinant protein expression and purification, cell culture and transfection, cell labeling, reporter assays, flow cytometry, yeast-two hybrid, immunoprecipitation, immunoblotting, immunofluorescence, TUNEL assay, ELISA assay, Southern blotting, and protein and gene expression.