RESUMO
PURPOSE: To study the expression of insulin-like growth factor binding proteins (IGFBPs) in paclitaxel-treated gastric cancer SGC-7901 cells, and to further investigate underlying mechanisms. MATERIALS AND METHODS: Real time PCR and Western blot assays were applied to detect the mRNA and protein expression of IGFBP-2, -3 and -5 after paclitaxel (10 nM) treatment of SGC-7901 cells. In addition IGFBP-3 expression was silenced by RNA interference to determine effects. Cell viability was determined by MTT assay. Cell cycling and apoptosis were assessed by flow cytometry. RESULTS: Compared to the control group, only IGFBP-3 expression was elevated significantly after paclitaxel (10 nM) treatment (p<0.05). Paclitaxel treatment caused cell cycle arrest and apoptosis via downregulating Bcl-2 expression. However, the effect could be abrogated by IGFBP-3 silencing. CONCLUSIONS: IGFBP-3 exhibits anti-apoptotic effects on paclitaxel-treated SGC-7901 cells via elevating Bcl-2 expression.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose/genética , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Paclitaxel/farmacologia , Neoplasias Gástricas/tratamento farmacológico , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Humanos , Proteína 2 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/biossíntese , Proteína 5 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Interferência de RNA , RNA Mensageiro/biossíntese , RNA Interferente Pequeno , Neoplasias Gástricas/patologia , Moduladores de Tubulina/farmacologiaRESUMO
AIM: To investigate effects of sulforaphane on the BIU87 cell line and underlying mechanisms involving IGFBP-3. METHODS: Both BIU87 and IGFBP-3-silenced BIU87 cells were treated with sulforaphane. Cell proliferation was detected by MTT assay. Cell cycle and apoptosis were determined via flow cytometry. Quantitative polymerase chain reaction and Western blotting were applied to analyze the expression of IGFBP-3 and NF-κB at both mRNA and protein levels. RESULTS: Sulforaphane (80 µM) treatment could inhibit cell proliferation, inducing apoptosis and cell cycle arrest at G2/M phase. All these effects could be antagonized by IGFBP-3 silencing. Furthermore, sulforaphane (80 µM) could down-regulate NF-κB expression while elevating that of IGFBP-3. CONCLUSIONS: Sulforaphane could suppress the proliferation of BIU87 cells via enhancing IGFBP-3 expression, which negatively regulating the NF-κB signaling pathway.