epidermal-growth-factor and Carcinoma--Lewis-Lung

Sphingosine-1-phosphate (S1P) regulates a wide array of biological functions. However, the role of S1P signaling in tumorigenesis remains to be elucidated. In this study, we show that S1P receptor subtype 3 (S1P₃) is markedly up-regulated in a subset of lung adenocarcinoma cells compared to normal lung epithelial cells. Specific knockdown of S1P₃ receptors inhibits proliferation and anchorage-independent growth of lung adenocarcinoma cells. Mechanistically, we demonstrate that S1P₃ signaling increases epidermal growth factor receptor (EGFR) expression via the Rho kinase (ROCK) pathway in lung adenocarcinoma cells. Nuclear run-off analysis indicates that S1P/S1P₃ signaling transcriptionally increases EGFR expression. Knockdown of S1P₃ receptors diminishes the S1P-stimulated EGFR expression in lung adenocarcinoma cells. Moreover, S1P treatment greatly enhances EGF-stimulated colony formation, proliferation and invasion of lung adenocarcinoma cells. Together, these results suggest that the enhanced S1P₃-EGFR signaling axis may contribute to the tumorigenesis or progression of lung adenocarcinomas.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Animals; Carcinoma, Lewis Lung; Cell Line, Tumor; Cell Movement; Cell Proliferation; Epidermal Growth Factor; ErbB Receptors; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Humans; Lung Neoplasms; Lysophospholipids; Mice; Neoplasm Invasiveness; Receptors, Lysosphingolipid; rho-Associated Kinases; RNA Interference; RNA, Messenger; Signal Transduction; Sphingosine; Sphingosine-1-Phosphate Receptors; Time Factors; Transcriptional Activation; Transfection; Up-Regulation

ATP, which has an important proinflammatory action as danger signal, induces the semimaturation of dendritic cells (DCs) that can be associated with immune tolerance. We identified epidermal growth factor receptor ligands as target genes of ATPγS, a slowly hydrolyzed ATP derivative, by a gene profiling approach in DCs. Amphiregulin was the most highly up-regulated gene in response to ATPγS. Human monocyte-derived DCs and mouse bone marrow-derived DCs released amphiregulin (AREG) after purinergic receptor activation, with a contribution of P2Y(11) and A(2B) receptor, respectively. Supernatants of LPS+ATPγS-stimulated DCs induced smooth muscle cell and Lewis Lung Carcinoma (LLC) cell growth in vitro. The coinjection of LPS+ATPγS-stimulated DCs or their supernatants with LLC cells increased tumor weight in mice compared with LPS-treated DCs. The preincubation of LPS+ATPγS-treated DC supernatants with an anti-AREG blocking antibody inhibited their positive effect on smooth muscle cell density and tumor growth. The present study demonstrates for the first time that DCs can be a source of AREG. ATP released from tumor cells might exert a tumorigenic action by stimulating the secretion of AREG from DCs. Antagonists of purinergic receptors expressed on DCs and anti-AREG blocking antibodies could have a therapeutic potential as antitumor agents.

Topics: Adenosine Triphosphate; Amphiregulin; Animals; Bone Marrow Cells; Carcinoma, Lewis Lung; Cell Line, Tumor; Cell Proliferation; Dendritic Cells; EGF Family of Proteins; Epidermal Growth Factor; Gene Expression Regulation, Neoplastic; Glycoproteins; Humans; Intercellular Signaling Peptides and Proteins; Lipopolysaccharides; Male; Mice; Mice, Inbred C57BL; Monocytes; Myocytes, Smooth Muscle; Up-Regulation

The exact role of a disintegrin and metalloproteinase with thrombospondin motifs-1 (ADAMTS-1) and the underlying mechanism of its involvement in tumor metastasis have not been established. We have now demonstrated that overexpression of ADAMTS-1 promotes pulmonary metastasis of TA3 mammary carcinoma and Lewis lung carcinoma cells and that a proteinase-dead mutant of ADAMTS-1 (ADAMTS-1E/Q) inhibits their metastasis, indicating that the prometastatic activity of ADAMTS-1 requires its metalloproteinase activity. Overexpression of ADAMTS-1 in these cells promoted tumor angiogenesis and invasion, shedding of the transmembrane precursors of heparin-binding epidermal growth factor (EGF) and amphiregulin (AR), and activation of the EGF receptor and ErbB-2, while overexpression of ADAMTS-1E/Q inhibited these events. Furthermore, we found that ADAMTS-1 undergoes auto-proteolytic cleavage to generate the NH(2)- and COOH-terminal cleavage fragments containing at least one thrombospondin-type-I-like motif and that overexpression of the NH(2)-terminal ADAMTS-1 fragment and the COOH-terminal ADAMTS-1 fragment can inhibit pulmonary tumor metastasis. These fragments also inhibited Erk1/2 kinase activation induced by soluble heparin-binding EGF and AR. Taken together, our results suggest that the proteolytic status of ADAMTS-1 determines its effect on tumor metastasis, and that the ADAMTS-1E/Q and the ADAMTS-1 fragments likely inhibit tumor metastasis by negatively regulating the availability and activity of soluble heparin-binding EGF and AR.

Topics: ADAM Proteins; ADAMTS1 Protein; Amino Acid Sequence; Amphiregulin; Animals; Apoptosis; Carcinoma, Lewis Lung; Cell Proliferation; Collagen; Drug Combinations; EGF Family of Proteins; Epidermal Growth Factor; ErbB Receptors; Female; Glycoproteins; Heparin-binding EGF-like Growth Factor; Humans; Intercellular Signaling Peptides and Proteins; Laminin; Lung Neoplasms; Mammary Neoplasms, Experimental; Mice; Mice, Inbred C57BL; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Molecular Sequence Data; Neoplasm Invasiveness; Neovascularization, Pathologic; Proteoglycans; Receptor, ErbB-2; Sequence Deletion; Sequence Homology, Amino Acid; Signal Transduction