tosylphenylalanyl-chloromethyl-ketone and Neoplasm-Metastasis

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

Three synthetic irreversible enzyme inhibitors (75 microM di-iso-propylphosphorofluoridate (DFP), 310 microM N alpha-p-tosyl-L-lysine (TLCK) and 240 microM L-1-tosylamide-2-phenylethyl (TPCK) chloromethyl ketone), as well as the transition state analogue chymostatin, inhibit the development of Lewis lung adenocarcinoma (3LL) in C57 BI/6 mice, when 3LL cells are treated once and for a limited period (60 min) prior to grafting. These compounds demonstrate divergent protease specificity and, in the case of TLCK and TPCK, convergent reactivity toward the highly conserved protein kinase catalytic subunit. Using 200 microM chymostatin and low doses (25-40 microM) of the irreversible enzyme inhibitors, the antimetastatogenic effect is revealed to be specific, as primary tumor development is not affected. Although no direct experimental evidence can be forwarded, our results fit with the concept that the motile metastatogenic 3LL cells may constitute a phenotype which, in contrast to the resident cells from the primaries, responds to these enzyme inhibitors in a highly sensitive manner.

Topics: Affinity Labels; Animals; Female; Isoflurophate; Lung Neoplasms; Mice; Mice, Inbred C57BL; Neoplasm Metastasis; Neoplasm Transplantation; Protease Inhibitors; Protein Kinases; Tosyllysine Chloromethyl Ketone; Tosylphenylalanyl Chloromethyl Ketone