RESUMO
Gastric cancer (GC) is one of the leading causes of cancer death in the world. The role of histone deacetylase 4 (HDAC4) in specific cell and tissue types has been identified. However, its biological roles in the development of gastric cancer remain largely unexplored. Quantitative real time PCR (qRT-PCR) and western blot were used to analyze the expression of HDAC4 in the clinical samples. siRNA and overexpression of HDAC4 and siRNA p21 were used to study functional effects in a proliferation, a colony formation, a adenosine 5'-triphosphate (ATP) assay and reactive oxygen species(ROS) generation, cell cycle, cell apoptosis rates, and autophagy assays. HDAC4 was up-regulated in gastric cancer tissues and several gastric cancer cell lines. The proliferation, colony formation ability and ATP level were enhanced in HDAC4 overexpression SGC-7901 cells, but inhibited in HDAC4 knockdown SGC-7901 cells. HDAC4 knockdown led to G0/G1 phase cell arrest and caused apoptosis and ROS increase. Moreover, HDAC4 was found to inhibit p21 expression in gastric cancer SGC-7901 cells. p21 knockdown dramatically attenuated cell proliferation inhibition, cell cycle arrest, cell apoptosis promotion and autophagy up-regulation in HDAC4-siRNA SGC-7901 cells. We demonstrated that HDAC4 promotes gastric cancer cell progression mediated through the repression of p21. Our results provide an experimental basis for understanding the pro-tumor mechanism of HDAC4 as treatment for gastric cancer.
Assuntos
Inibidor de Quinase Dependente de Ciclina p21/genética , Regulação Neoplásica da Expressão Gênica , Histona Desacetilases/metabolismo , Proteínas Repressoras/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Trifosfato de Adenosina/metabolismo , Idoso , Apoptose/genética , Estudos de Casos e Controles , Pontos de Checagem do Ciclo Celular/genética , Linhagem Celular Tumoral , Proliferação de Células , Histona Desacetilases/genética , Humanos , Pessoa de Meia-Idade , Espécies Reativas de Oxigênio/metabolismo , Proteínas Repressoras/genética , Neoplasias Gástricas/patologia , Ensaio Tumoral de Célula-TroncoRESUMO
OBJECTIVE: To study the effect of acupuncture on tumor and its mechanism. METHODS: Liver cancer, gastric cancer and hypodermic tumor rat models were made by implantation of replicated Walker-256 cell strain. The 3 model rats were respectively divided into two groups at random, a model control group and an electroacupuncture group. The electroacupuncture groups were treated with electroacupuncture (EA) at "Zusanli" (ST 36), "Hegu" (LI 4) and "San-yinjiao" (SP 6), once each day, 15 min one session, for 15 days. The gross tumor volume and the tumor inhibitory rate, and the levels of humoral immunity index, including serum 1gG, IgM, IgA and C3, C4, and the levels of cellular immunity index, including CD4+, CD8+ and CD4+/CD8+ in the peripheral blood in each group were detected. RESULTS: The gross tumor volumes in the EA groups were significantly smaller than those in the model control group (P<0.01). The contents of IgG, IgM and C3 in the EA groups increased significantly compared with those in the model control group (P<0.05 or P<0.01). The contents of IgA and C4 in the EA groups did not significantly change (P>0.05). The content of CD4+ and CD4+/CD8+ in the EA groups are significantly higher than those in the model control group (P<0.05 or P<0.01). CONCLUSION: Acupuncture at "Zusanli" (ST 36), "Hegu" (LI 4) and "Sanyinjiao" (SP 6) can increase immune function and inhibit tumor growth in Walker-256 liver cancer, gastric cancer and hypodermic tumor rats.