ABSTRACT
Lysophosphatidic acid (LPA) is a bioactive phospholipids and involves in various cellular events, including tumor cell migration. In the present study, we investigated LPA receptor and its transactivation to EGFR for cyclooxygenase-2 (COX-2) expression and cell migration in CAOV-3 ovarian cancer cells. LPA induced COX-2 expression in a dose-dependent manner, and pretreatment of the cells with pharmacological inhibitors of Gi (pertussis toxin), Src (PP2), EGF receptor (EGFR) (AG1478), ERK (PD98059) significantly inhibited LPA- induced COX-2 expression. Consistent to these results, transfection of the cells with selective Src siRNA attenuated COX-2 expression by LPA. LPA stimulated CAOV-3 cell migration that was abrogated by pharmacological inhibitors and antibody of EP2. Higher expression of LPA2 mRNA was observed in CAOV-3 cells, and transfection of the cells with a selective LPA2 siRNA significantly inhibited LPA-induced activation of EGFR and ERK, as well as COX-2 expression. Importantly, LPA2 siRNA also blocked LPA-induced ovarian cancer cell migration. Collectively, our results clearly show the significance of LPA2 and Gi/Src pathway for LPA-induced COX-2 expression and cell migration that could be a promising drug target for ovarian cancer cell metastasis.
Subject(s)
Female , Humans , Butadienes/pharmacology , Cell Line, Tumor , Cell Movement/drug effects , Cyclooxygenase 2/biosynthesis , Extracellular Signal-Regulated MAP Kinases/antagonists & inhibitors , Flavonoids/pharmacology , GTP-Binding Protein alpha Subunits, Gi-Go/antagonists & inhibitors , Lysophospholipids/pharmacology , Nitriles/pharmacology , Ovarian Neoplasms/metabolism , Pertussis Toxin/pharmacology , Protein-Tyrosine Kinases/antagonists & inhibitors , Proto-Oncogene Proteins/antagonists & inhibitors , Pyrimidines/pharmacology , ErbB Receptors/antagonists & inhibitors , Receptors, Lysophosphatidic Acid/metabolism , Receptors, Prostaglandin E/metabolism , Signal Transduction , Transcriptional Activation , Tyrphostins/pharmacologyABSTRACT
(...) Com o objetivo de abordar tais vias parasito, estudamos bioquimicamente e citoquimicamente a atividade fosfatase ácida. Parasitos tratados com os três inibidores po 1h e 24h apresetaram atividade fosfatase ácida secretada significativametne dimunuída. com a finalidade de estudar as vias de sinalização do parasito na interação com a célula hospedeira, promastigotas pré-tratados com os antagonistas foram incubados com macrófagos peritoneais. Observamos que estaurosporina 1μM inibiu, de forma significativa, a internalização e a sobrevivência intracelular dos parasitos. Nossos dados sugerem que inibidores de proteína cinases podem exercer efeitos na morfologia, infectividade e proliferação de Leishmania, bloqueando o ciclo celular desses parasitos.
Subject(s)
Phosphorylation , In Vitro Techniques , Enzyme Inhibitors/metabolism , Leishmania mexicana/enzymology , Protein Kinase C/physiology , Blotting, Western , Electrophoresis, Polyacrylamide Gel , Staurosporine/pharmacology , Genistein/pharmacology , Microscopy, Electron, Transmission , Phosphorylation , Host-Parasite Interactions , Tyrphostins/pharmacologyABSTRACT
1) A beta agonist stimulated Na+ transport and decreased the intracellular Cl concentration ([Cl]c) associated with cell shrinkage via an increase in cytosolic cAMP level by activating adenylate cyclase in rat fetal distal lung epithelial (FDLE) cells. 2) Lowering [Cl-]c activated a 28-pS nonselective cation (NSC) channel by elongating the open time of the channel. 3) cAMP signals were converted to a protein tyrosine kinase (PTK)-mediated signal. 4) The PTK-mediated signal was involved in the cAMP-stimulated Na+ transport in rat FDLE cells.