RESUMO
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.
Assuntos
Feminino , Humanos , Butadienos/farmacologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Ciclo-Oxigenase 2/biossíntese , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , Flavonoides/farmacologia , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/antagonistas & inibidores , Lisofosfolipídeos/farmacologia , Nitrilas/farmacologia , Neoplasias Ovarianas/metabolismo , Toxina Pertussis/farmacologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Pirimidinas/farmacologia , Receptores ErbB/antagonistas & inibidores , Receptores de Ácidos Lisofosfatídicos/metabolismo , Receptores de Prostaglandina E/metabolismo , Transdução de Sinais , Ativação Transcricional , Tirfostinas/farmacologiaRESUMO
(...) 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.
Assuntos
Fosforilação , Técnicas In Vitro , Inibidores Enzimáticos/metabolismo , Leishmania mexicana/enzimologia , Proteína Quinase C/fisiologia , Western Blotting , Eletroforese em Gel de Poliacrilamida , Estaurosporina/farmacologia , Genisteína/farmacologia , Microscopia Eletrônica de Transmissão , Fosforilação , Interações Hospedeiro-Parasita , Tirfostinas/farmacologiaRESUMO
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.