RESUMO
Astrocyte elevated gene-1 (AEG-1) plays a critical role in the development, progression, and metastasis of a variety of cancers, including non-small-cell lung cancer (NSCLC). The objective of the current study is to unravel the upstream signaling of AEG-1. A cohort of 28 NSCLC tissues and 30 normal tissues were collected. Quantitative reverse transcription-polymerase chain reaction and Western blotting were used to examine AEG-1, migration, and invasion related markers in NSCLC cells. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay coupled with colony formation assay were conducted to monitor cell growth. Transwell assay was performed to determine cell migration and invasion. Apoptotic cells were detected by costaining with Annexin-V-fluorescein isothiocyanate and propidium iodide. Immunofluorescent staining was used to observe the levels of migration and invasion related markers. Xenograft models were used to investigate tumor formation in vivo. Dual-luciferase reporter assay and RNA immunoprecipitation were carried out to determine the interaction between circMTDH.4 and miR-630, as well as the associated between miR-630 and AEG-1. AEG-1 was highly expressed in NSCLC tissues and cell lines. Silencing of AEG-1 inhibited cell proliferation, migration, invasion, and chemoresistance/radioresistance in NCI-H1650 and A549 cells. circMTDH.4 regulated AEG-1 expression via sponging miR-630. Knockdown of circMTDH.4 and/or overexpression of miR-630 inhibited chemoresistance and radioresistance in NSCLC cells, whereas overexpression of AEG-1 or knockdown of miR-630 exerted rescue effects. circMTDH.4/miR-630/AEG-1 axis is responsible for chemoresistance and radioresistance in NSCLC cells.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/genética , Proteínas de Membrana/genética , MicroRNAs/genética , RNA Circular/genética , Proteínas de Ligação a RNA/genética , Células A549 , Animais , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/terapia , Linhagem Celular Tumoral , Quimiorradioterapia , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/terapia , Camundongos Endogâmicos BALB C , Camundongos Nus , Invasividade Neoplásica , Interferência de RNA , Tolerância a Radiação/genética , Transplante HeterólogoRESUMO
We aimed to investigate the influence of radiation on hypoxia-treated breast cancers cells and its underlying mechanism. We mimicked the hypoxic response in MCF-7 cells by the treatment of CoCl2. Meanwhile, hypoxic MCF-7 cells induced by CoCl2 or untreated MCF-7 cells were treated with or without radiation, and then treated with or without hypoxia inducible factors-1α (HIF-1α) inhibitor. Subsequently, glucose update and lactate release rate were determined by commercial kits, as well as the expressions of HIF-1α and the glucose metabolic pathway related genes, including fructose biphoshatase 1 (FBP1), glucose transporter 1 (GLUT1), lactate dehydrogenase A (LDHA), hexokinase 2 (HK2), and isocitrate dehydrogenase 2 (IDH20) were detected by western blotting and/or RT-PCR. The results showed that glucose uptake rate and lactate release rate were increased in cells under hypoxia and/or radiation condition compared with untreated cells (p < 0.05), while the addition of HIF-1α inhibitor decreased these rates in hypoxia + radiation treated cells (p < 0.05). In addition, compared with untreated cells, the mRNA and protein levels of HIF-1α were significantly increased under hypoxia and radiation condition (p < 0.05), while which decreased after the addition of HIF-1α inhibitor (p < 0.05). Similar content changing trends (all p < 0.05) were observed in FBP1, IDH2, GLUT1, and LDHA but not HK2. In conclusion, the combination of radiation and hypoxia could promote the glucose metabolism. Furthermore, HIF-1α might inhibit the promoting effect of radiation on glycolysis in hypoxic MCF-7 cells by regulating the glucose metabolic pathway.