RESUMO
BACKGROUND: Long noncoding RNA colon cancer-associated transcript 1 (LncRNA CCAT1) is highly expressed in gastric cancer tissues and plays a role in autophagy. However, the underlying mechanism still needs to be further clarified. OBJECTIVE: To study the role of LncRNA CCAT1 in regulating autophagy of gastric cancer cells, analyze its downstream targets, and elucidate the mechanism. METHODS: qPCR detected the expression of LncRNA CCAT1 in gastric cancer cells. The proliferation, migration, and invasion ability of LncRNA CCAT1 and the expression level of autophagy-related proteins in gastric cancer cells were detected. Bioinformatics method predicted the downstream targets of LncRNA CCAT1, and they were verified by dual-luciferase assay. The relationship between LncRNA CCAT1, miR-140, and ATG5 was verified by co-transfection, and the expression levels of ATG5 and ATG5-ATG12 complex proteins were detected. Finally, the role of LncRNA CCAT1 in vivo was confirmed by gastric cancer transplantation model. RESULTS: LncRNA CCAT1 was highly expressed in gastric cancer cells. LncRNA CCAT1 can promote the proliferation, migration, invasion, and autophagy activity of gastric cancer cells. LncRNA CCAT1 can bind to miR-140-3p and regulate its expression, while miR-140-3p further regulates the expression of ATG5. Overexpression of LncRNA CCAT1 can promote tumor growth in nude mice. After LncRNA CCAT1 silencing, the positive expression rate of ATG5 in nude mice was low. CONCLUSION: LncRNA CCAT1 may inhibit the expression of miR-140-3p by sponge adsorption, thus weakening its inhibitory effect on ATG5. Eventually, gastric cancer cells were more prone to autophagy under the pressure of stress.
Assuntos
Neoplasias do Colo , MicroRNAs , RNA Longo não Codificante , Neoplasias Gástricas , Animais , Autofagia/genética , Proteína 5 Relacionada à Autofagia/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Neoplasias do Colo/genética , Regulação Neoplásica da Expressão Gênica , Camundongos , Camundongos Nus , MicroRNAs/genética , RNA Longo não Codificante/genética , Neoplasias Gástricas/patologiaRESUMO
Several Chinese herbs, namely, Pu-Gong-Ying, Gan-Cao, Chai-Hu, Mu-Xiang, Gua-Lou and Huang-Yao-Zi, are frequently used in complex traditional Chinese medicing formulas for breast hyperplasia and breast tumor therapy. The pharmacological effects of these Chinese herbs are all described as 'clearing heat-toxin and resolving masses' in traditional use. However, the chemical profiles of anti-breast cancer constituents in these herbs has not been investigated so far. In this study, a bioactivity-oriented screening platform, which was based on a human breast cancer MCF-7 cellular model, semi-preparative high performance liquid chromatography coupled with ultraviolet spectrophotometry and ultraperformance liquid chromatography coupled to quadrupole-time-of-flight mass spectrometer, was developed to rapidly screen the six Chinese herbs. Two potential anti-breast cancer compounds, which were costunolide (Cos) and dehydrocostus lactone (Dehy), were identified in Mu-Xiang. Combination of the two compounds showed a synergism on inhibiting the proliferation of MCF-7 cells in vitro, which exhibits a potential application prospect for breast cancer therapy. This bioactivity-oriented screening strategy is rapid, economical, reliable and specific for screening potential anti-breast cancer compounds in traditional Chinese medicines.