tosylphenylalanyl-chloromethyl-ketone and Carcinoma--Squamous-Cell

We reported previously that tumor cells isolated from metastases of the in vitro transformed squamous cell carcinoma line Pam 212 exhibit an elevation in constitutive production of proinflmmatory cytokines interleukin (IL)-1alpha, IL-6, granulocyte-macrophage colony-stimulating factor, and KC (the murine homologue of chemokine Gro-alpha). The basis for constitutive expression of these cytokines after tumor progression in vivo is unknown. Regulation of the expression of these proinflammatory cytokines involves transcription factor nuclear factor kappaB (NF-kappaB), which can be activated by cytokines such as tumor necrosis factor (TNF)-alpha. In this study, we compared the constitutive and TNF-alpha-induced expression of proinflammatory cytokines in parental Pam 212 and metastatic LY-2 and LY-8 cell lines and determined the relationship of cytokine expression to activation of NF-kappaB. We found that the metastatic cell lines exhibited an increase in constitutive and TNF-alpha-inducible expression of proinflammatory cytokines when compared with parental Pam 212 cells. The increased cytokine expression was associated with an increase in constitutive and TNF-alpha-inducible activation of NF-kappaB as demonstrated by electrophoretic mobility shift assay and luciferase-reporter gene assay. Constitutive nuclear localization of NF-kappaB p65 was observed in LY-2 and LY-8 cells in culture and in tumor specimens but rarely in Pam 212 cells, consistent with the constitutive activation of NF-kappaB in tumor cels after selection in vivo. Induction of NF-kappaB by TNF-alpha was inhibited by the addition of protease inhibitors calpain inhibitor I and N-tosyl-phechloromethyl ketone and antioxidant 1-pyrrolidinecarbodithioic acid, whereas constitutive activation of NF-kappaB and cytokine KC mRNA expression was inhibited by N-tosyl-phechloromethyl ketone alone. Overexpression of a human Ikappa(B)alpha dominant suppresser in Pam 212 cells inhibited TNF-alpha-induced NF-kappaB binding activity and KC expression. These data indicate that activation of NF-kappaB contributes to increased expression of proinflammatory cytokines during metastatic tumor progression of squamous cell carcinoma, and that distinct mechanisms may be involved in the regulation of constitutive and TNF-alpha-induced activation of NF-kappaB in squamous cell carcinoma.

Topics: Animals; Carcinoma, Squamous Cell; Cell Nucleus; Cytokines; Cytoplasm; DNA-Binding Proteins; Gene Expression Regulation, Neoplastic; Genes, Reporter; Granulocyte-Macrophage Colony-Stimulating Factor; Humans; I-kappa B Proteins; Inflammation; Interleukin-1; Interleukin-6; Mice; Mice, Inbred BALB C; Neoplasm Metastasis; Neoplasm Proteins; Neoplasm Transplantation; NF-kappa B; NF-KappaB Inhibitor alpha; Promoter Regions, Genetic; Protease Inhibitors; Pyrrolidines; Recombinant Fusion Proteins; Selection, Genetic; Thiocarbamates; Tosylphenylalanyl Chloromethyl Ketone; Transcription Factor RelA; Transplantation, Heterologous; Tumor Cells, Cultured; Tumor Necrosis Factor-alpha

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Carcinogens; Carcinoma, Squamous Cell; Cell Transformation, Neoplastic; Cocarcinogenesis; Croton Oil; Fluocinolone Acetonide; Mice; Mice, Inbred Strains; Papilloma; Skin; Skin Neoplasms; Tetradecanoylphorbol Acetate; Tosylphenylalanyl Chloromethyl Ketone; Tretinoin

Topics: Amino Acids; Canavanine; Carcinoma, Squamous Cell; Cell Line; Cycloheximide; Macromolecular Substances; Molecular Weight; Peptide Biosynthesis; Protein Biosynthesis; Simplexvirus; Tosyllysine Chloromethyl Ketone; Tosylphenylalanyl Chloromethyl Ketone; Viral Proteins