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MINI 34 - RNA and miRNA (ID 162)
- Event: WCLC 2015
- Type: Mini Oral
- Track: Biology, Pathology, and Molecular Testing
- Presentations: 1
MINI34.08 - MiR-33B Inhibit EMT Through Wnt/β-Catenin/ZEB1 Pathway in Lung Adenocarcinoma (ID 236)
18:30 - 20:00 | Author(s): J.J. Qu
Lung adenocarcinoma is one of the main pathological tissue types of lung small cell lung cancer (NSCLC). Tumor metastases are responsible for approximately 90% of lung adenocarcinoma-related death. The epithelial–mesenchymal transition (EMT) is regarded as a critical event during tumor metastasis. From our previous study, we found miR-33b might be involved in the EMT process of lung adenocarcinoma. However, the specific mechanism of miR-33b regulating EMT has not been established.
Quantitative real time-PCR (qRT-PCR), in situ hybridization and immunohistochemistry were used to investigate expression of miR-33b and ZEB1 in paired lung adenocarcinoma tissues. MiR-33b target gene ZEB1 was investigated using luciferase reporter gene assays. Western blot, qRT-PCR, immunofluorescence were used to compare the expression levels of ZEB1, E-cad, Vim and β-catenin in A549 cells which were transfected miR-33b or miR-NC, anti-miR-33b or anti-miR-NC and in vivo. MTT was used to analysis growth curves of transfected cells with miR-33b or miR-NC, anti-miR-33b or anti-miR-NC, siRNA-NC or siRNA -ZEB1, siRNA-NC or siRNA-β-catenin. The transfected cells were subjected to Transwell migration and invasion assays.
Mean miR-33b levels were significantly lower in lung adenocarcinoma tissues compared with matched non-cancerous tissues (0.024± 0.028 vs 0.063 ± 0.074, P < 0.0001). The level of miR-33b in NSCLC was strongly correlated with lymph node metastasis (P < 0.0001). ZEB1 levels were significantly higher in lung adenocarcinoma tissues compared with matched non-cancerous tissues (0.447± 0.371vs0.084 ± 0.112, P <0.0001). The level of miR-33b in lung adenocarcinoma was negative correlated with ZEB1 (P < 0.0001,r=-0.6077). MiR-33b significantly inhibited EMT in lung adenocarcinoma metastasis in vitro and vivo (P < 0.05).MiR-33b directly targets the ZEB13[']UTR(P < 0.01).β-catenin was down regulation by overexpression of miR-33b (P < 0.01). MiR-33b overexpression and ZEB1 inhibition suppressed lung adenocarcinoma migration and invasion in vitro (P < 0.01).
On the basis of our results, we propose that miR-33b suppress EMT in lung adenocarcinoma through direct targeting of ZEB1 in vitro and in vivo. Moreover, we found that Wnt/β-catenin/ZEB1 pathway regulated by miR-33b might involved in lung adenocarcinoma EMT. These findings provide new insights into the molecular functions of miR-33b as well asthe role of ZEB1 in lung adenocarcinoma metastasis.