ono-8711 and Liver-Neoplasms

To investigate the effects of (-)-epigallocatechin-3-gallate (EGCG), an active compound in green tea, on prostaglandin E(2) (PGE(2))-induced proliferation and migration, and the expression of prostanoid EP(1) receptors in hepatocellular carcinoma (HCC) cells.. HCC cell line HepG2, human hepatoma cell lines MHCC-97L, MHCC-97H and human hepatocyte cell line L02 were used. Cell viability was analyzed using MTT assay. PGE(2) production was determined with immunoassay. Wound healing assay and transwell filter assay were employed to assess the extent of HCC cell migration. The expression of EP(1) receptor and Gq protein were examined using Western blot assay.. PGE(2) (4-40000 nmol/L) or the EP(1) receptor agonist ONO-DI-004 (400-4000 nmol/L) increased the viability and migration of HepG2 cells in concentration-dependent manners. EGCG (100 μg/mL) significantly inhibited the viability and migration of HepG2 cells induced by PGE(2) or ONO-DI-004. HepG2 cells secreted an abundant amount of PGE(2) into the medium, and EGCG (100 μg/mL) significantly inhibited the PGE(2)production and EP(1) receptor expression in HepG2 cells. EGCG (100 μg/mL) also inhibited the viability of MHCC-97L cells, but not that of MHCC-97H cells. Both EGCG (100 μg/mL) and EP(1) receptor antagonist ONO-8711 inhibited PGE(2) 4 μmol/L and ONO-DI-004 400 nmol/L-induced growth and migration of HepG2 cells. Both EGCG (100 μg/mL) and ONO-8711 210 nmol/L inhibited PGE(2)- and ONO-DI-004-induced EP(1) expression. EGCG and ONO-8711 had synergistic effects in inhibiting EP(1) receptor expression. PGE(2), ONO-DI-004, ONO-8711, and EGCG had no effects on Gq expression in HepG2 cells, respectively.. These findings suggest that the anti-HCC effects of EGCG might be mediated, at least partially, through the suppressing EP(1) receptor expression and PGE(2) production.

Topics: Alprostadil; Antineoplastic Agents, Phytogenic; Blotting, Western; Bridged Bicyclo Compounds; Caproates; Carcinoma, Hepatocellular; Catechin; Cell Movement; Cell Proliferation; Cell Survival; Dinoprostone; Dose-Response Relationship, Drug; GTP-Binding Protein alpha Subunits, Gq-G11; Hep G2 Cells; Humans; Immunoassay; Liver Neoplasms; Neoplasm Invasiveness; Receptors, Prostaglandin E, EP1 Subtype; Time Factors

Recent evidence indicates that cyclooxygenase-2 (COX-2) and epidermal growth factor receptor (EGFR) are involved in hepatocarcinogenesis. This study was designed to evaluate the possible interaction between the COX-2 and EGFR signaling pathways in human hepatocellular carcinoma (HCC) cells. Immunohistochemical analysis using serial sections of human HCC tissues revealed positive correlation between COX-2 and EGFR in HCC cells (P < 0.01). Overexpression of COX-2 in cultured HCC cells (Hep3B) or treatment with PGE(2) or the selective EP(1) receptor agonist, ONO-DI-004, increased EGFR phosphorylation and tumor cell invasion. The PGE(2)-induced EGFR phosphorylation and cell invasiveness were blocked by the EP(1) receptor siRNA or antagonist ONO-8711 and by two EGFR tyrosine kinase inhibitors, AG1478 and PD153035. The EP(1)-induced EGFR transactivation and cell invasion involves c-Src, in light of the presence of native binding complex of EP(1)/Src/EGFR and the inhibition of PGE(2)-induced EGFR phosphorylation and cell invasion by the Src siRNA and the Src inhibitor, PP2. Further, overexpression of COX-2 or treatment with PGE(2) also induced phosphorylation of c-Met, another receptor tyrosine kinase critical for HCC cell invasion. Moreover, activation of EGFR by EGF increased COX-2 promoter activity and protein expression in Hep3B and Huh-7 cells, whereas blocking PGE(2) synthesis or EP(1) attenuated EGFR phosphorylation induced by EGF, suggesting that the COX-2/PGE(2)/EP(1) pathway also modulate the activation of EGFR by its cognate ligand. These findings disclose a cross-talk between the COX-2/PGE(2)/EP(1) and EGFR/c-Met signaling pathways that coordinately regulate human HCC cell invasion.

Topics: Alprostadil; Bridged Bicyclo Compounds; Caproates; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Movement; CSK Tyrosine-Protein Kinase; Cyclooxygenase 2; Dinoprostone; Enzyme Activation; ErbB Receptors; Gene Expression; Humans; Liver Neoplasms; Membrane Proteins; Neoplasm Invasiveness; Phosphorylation; Protein Binding; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-met; Receptors, Prostaglandin; Receptors, Prostaglandin E; Receptors, Prostaglandin E, EP1 Subtype; RNA Interference; RNA, Small Interfering; src-Family Kinases; Transfection