RESUMO
Asthma is an inflammatory disease associated with variable airflow obstruction and airway inflammation. This study aimed to explore the role and mechanism of extracellular adenosine diphosphate (ADP) in the occurrence of airway inflammation in asthma. The expression of ADP in broncho-alveolar lavage fluid (BALF) of asthmatic patients was determined by enzyme linked immunosorbent assay (ELISA) and the expression of P2Y1 receptor in lung tissues was determined by reverse transcription-quantitative polymerase chain reaction. Asthmatic mouse model was induced using ovalbumin and the mice were treated with ADP to assess its effects on the airway inflammation and infiltration of mast cells (MCs). Additionally, alveolar epithelial cells were stimulated with ADP, and the levels of interleukin-13 (IL-13) and C-X-C motif chemokine ligand 10 (CXCL10) were measured by ELISA. We finally analyzed involvement of NF-κB signaling pathway in the release of CXCL10 in ADP-stimulated alveolar epithelial cells. The extracellular ADP was enriched in BALF of asthmatic patients, and P2Y1 receptor is highly expressed in lung tissues of asthmatic patients. In the OVA-induced asthma model, extracellular ADP aggravated airway inflammation and induced MC infiltration. Furthermore, ADP stimulated alveolar epithelial cells to secrete chemokine CXCL10 by activating P2Y1 receptor, whereby promoting asthma airway inflammation. Additionally, ADP activated the NF-κB signaling pathway to promote CXCL10 release. As a "danger signal" extracellular ADP could trigger and maintain airway inflammation in asthma by activating P2Y1 receptor. This study highlights the extracellular ADP as a promising anti-inflammatory target for the treatment of asthma.
RESUMO
The aim of the present study was to determine the effect of the long noncoding RNA (lncRNA) bladder cancerassociated transcript 1 (BLACAT1) in chemoresistance of nonsmall cell lung cancer (NSCLC) cells. Expression of lncRNA BLACAT1, microRNA (miR)17, autophagyrelated protein 7 (ATG7), multidrugresistance protein 1 (MRP1), and the autophagyassociated proteins light chain 3 (LC3)II/LC3I and Beclin 1 were detected using the reverse transcriptionquantitative polymerase chain reaction and western blot analysis. Cell viability was determined using an MTT assay. The interaction between BLACAT1 and miR17 was determined using RNA immunoprecipitation and RNA pulldown assays. A cisplatin (DDP)resistant NSCLC cell A549/DDP xenograft model in nude mice was established to investigate the effect of BLACAT1 on the chemoresistance of NSCLC cells. Compared with in DDPsensitive NSCLC cells, expression of BLACAT1, ATG7, MRP1, LC3II/LC3I and Beclin 1 was significantly upregulated in DDPresistant NSCLC cells, whereas miR17 was downregulated in DDPresistant NSCLC cells. Short interfering RNA against BLACAT1 decreased the viability of DDPresistant NSCLC cells. In addition, BLACAT1 interacted with miR17, and negatively regulated miR17. BLACAT1 promoted ATG7 expression through miR17, and facilitated autophagy and promoted chemoresistance of NSCLC cells through miR17/ATG7. Finally, in vivo experiments indicated that inhibition of BLACAT1 ameliorated the chemoresistance of NSCLC. BLACAT1 was upregulated in DDPresistant NSCLC cells, and promoted autophagy and chemoresistance of NSCLC cells through the miR17/ATG7 signaling pathway.
Assuntos
Proteína 7 Relacionada à Autofagia/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Resistencia a Medicamentos Antineoplásicos , Neoplasias Pulmonares/genética , MicroRNAs/genética , RNA Longo não Codificante/genética , Células A549 , Animais , Autofagia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Cisplatino/uso terapêutico , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Camundongos , Transplante de Neoplasias , Transdução de SinaisRESUMO
MicroRNAs (miRNA) play an important role in tumorigenesis, proliferation, and differentiation. Altered miRNA expression in cancer indicates that miRNAs can function as tumor suppressors or oncogenes. MiR-449c downregulation in non-small cell lung cancer (NSCLC) compared with normal lung tissues was investigated in this study. NSCLC cell proliferation and invasion assays indicate that transfection of miR-449c expression plasmid inhibits the proliferation and invasion ability of NCI-H23 and NCI-H838 cells. In addition, miR-449c overexpression could suppress tumor growth in vivo. Morever, c-Myc was identified as a direct target gene of miR-449c. These findings clearly suggest that miR-449c downregulation and c-Myc amplification may be involved in the development of NSCLC.