RESUMO
The acquisition of metastasis potential is a critical point for malignant tumors. Melanoma differentiation associated gene-7/interleukin-24 (mda-7/IL-24) is a potential tumor suppress gene and frequently down-regulated in malignant tumors. It has been implicated that overexpression of MDA-7 led to proliferation inhibition in many types of human tumor. Invasion is an important process which is potential to promote tumor metastasis. However, the role and potential molecular mechanism of mda-7/IL-24 to inhibit the invasion of human melanoma cancer is not fully clear. In this report, we identified a solid role for mda-7/IL-24 in invasion inhibition of human melanoma cancer LiBr cells, including decreasing of adhesion and invasion in vitro, blocking cell cycle, down-regulating the expression of ICAM-1, MMP-2/9, CDK1, the phosphorylation of ERK and Akt, NF-kappaB and AP-1 transcription activity. Meanwhile, there was an increased expression of PTEN in mda-7/IL-24 over-expression LiBr cells. Our results demonstrated that mda-7/IL-24 is a potential invasion suppress gene, which inhibits the invasion of LiBr cells by the down-regulation of ICAM-1, MMP-2/9, PTEN, and CDK1 expression. The molecular pathways involved were the MAPK/ERK, PI3K-Akt, NF-kappaB, and AP-1. These findings suggest that mda-7/IL-24 may be used as a possible therapeutic strategy for human melanoma cancer.
Assuntos
Humanos , Proteína Quinase CDC2/genética , Linhagem Celular Tumoral , Movimento Celular , Regulação para Baixo , Pontos de Checagem da Fase G2 do Ciclo Celular , Molécula 1 de Adesão Intercelular/genética , Interleucinas/genética , Pontos de Checagem da Fase M do Ciclo Celular , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 9 da Matriz/genética , Melanoma/metabolismo , NF-kappa B/genética , PTEN Fosfo-Hidrolase/genética , Fosforilação , Proteínas Proto-Oncogênicas c-akt/genética , Fator de Transcrição AP-1/genética , Regulação para CimaRESUMO
<p><b>OBJECTIVE</b>To investigate the antiinflammatory activities of aqueous extract of Occimum gratissmium (OGE) with emphasis on expression of proinflammatory cytokines in Lipopolysaccharide (LPS)-stimulated epithelial cell BEAS-2B.</p><p><b>METHODS</b>Effects of OGE on cell viability were determined by MTT assay. mRNA expression were analyzed by and reverse transcription polymerase chain reaction (RT-PCR) and quantitative real-time PCR. Activation of kinase cascades was investigated by immunoblot. Intracellular reactive oxygen species (ROS) was analyzed by flow cytometry.</p><p><b>RESULTS</b>OGE (<200 μg/mL) treatment or pretreatment and following LPS exposure slightly affected viability of BEAS-2B cells. Increase of interleukin (IL)-6 and IL-8 and the elevated level of intracellular ROS in LPS-stimulated BEAS-2B cells were diminished by OGE pretreatment in a dose-dependent manner. OGE suppressed inflammatory response-associated mitogen-activated protein kinases (MAPKs) and Akt activation. Additionally, OGE pretreatment increased level of cellular inhibitor of κBα (IκBα) and inhibited nuclear translocation of nuclear factor kappa B (NF-κB).</p><p><b>CONCLUSION</b>These findings indicate that significant suppression of IL-6 and IL-8 expressions in LPS-stimulated BEAS-2B cells by OGE may be attributed to inhibiting activation of MAPKs and Akt and consequently suppressing nuclear translocation of NF-κB.</p>