MiR-20a promotes lung tumorigenesis by targeting RUNX3 via TGF-ß signaling pathway.

MiR-20a shows a significant role in the development of various human tumors. However, its specific biological function in non-small-cell lung cancer (NSCLC) is still not clear. qRT-PCR was applied for detecting miR-20a expression. The analysis of cell growth and apoptosis were performed by MTT, xenograft models, Western blot assays. Dual luciferase reporter, Western blotting and qRT-PCR were carried out to verify the potential target of miR-20a. In NSCLC tissues and cells, miR-20a was highly expressed and RUNX3 was lowly expressed. Moreover, up-regulation of miR-20a expression promoted NSCLC cell proliferation, invasion and migration, while low-expression of miR-20a showed the converse case on cell proliferation, invasion and migration. RUNX3 was verified as the direct target of miR-20a and it could overturn its biological function in NSCLC cells. Moreover, miR-20a negatively regulated RUNX3 expression. Mechanistically, increasing miR-20a expression inhibited RUNX3 expression and then activated the TGF-ß signaling pathway. Taken together, our results demonstrated that re-expression of miR-20a promoted lung tumorigenesis by down-regulation of RUNX3 and facilitating the activation of TGF-ß signaling pathway.

microRNA-23B inhibits non-small cell lung cancer proliferation, invasion and migration via downregulation of RUNX2 and inhibition of Wnt/Β-catenin signaling pathway.

Non-small cell lung cancer (NSCLC) accounts for about 85% of all lung cancer cases. MicroRNAs (miRNAs/miRs) have been reported to play significant roles in the progression of human tumors, however, the expression and biological role of miR-23b in NSCLC remains elusive. Underexpression of miR-23b was detected in NSCLC tissues in comparison with the matched para-carcinoma tissues. The clinical value of miR-23b was analyzed, and the findings showed that miR-23b expression was negatively correlated with poor overall survival and malignant clinicopathologic characteristics of NSCLC patients. Furthermore, functional assays demonstrated that overexpression of miR-23b inhibited NSCLC cell viability, invasion and migration. Luciferase reporter assay and qRT-PCR revealed that RUNX2 was a functional target of miR-23b. The elevated expression of RUNX2 was positively correlated with overall survival of NSCLC patients. Additionally, Western blot analysis indicated that EMT and Wnt/ß-catenin pathways were blocked by the upregulation of miR-23b. Taken together, these data demonstrated that dysregulation of miR-23b/RUNX2 signal may be a novel therapeutic target for the treatment of NSCLC.

LINC00460 promotes proliferation and inhibits apoptosis of non-small cell lung cancer cells through targeted regulation of miR-539.

OBJECTIVE: To explore the effects of long intergenic non-coding ribonucleic acid 00460 (LINC00460) on the proliferation and apoptosis of non-small cell lung cancer (NSCLC) cells. MATERIALS AND METHODS: In this study, the expression of LINC00460 in lung cancer tissues and its prognostic potential in NSCLC patients were analyzed using the Gene Expression Profiling Interactive Analysis (GEPIA) website and the Cancer Genome Atlas (TCGA) database. Then, the influences of silenced LINC00460 on proliferation and apoptosis in A549 cells were observed via methyl thiazolyl tetrazolium (MTT) assay, colony formation assay, and flow cytometry in vitro. Moreover, Dual-Luciferase reporter assay and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) were performed to detect the targeting relationship between LINC00460 and micro RNA (miR)-539. The biological role of the LINC00460/miR-539 axis in the proliferation of A549 cells was examined using MTT assay. RESULTS: It was found that the expression level of LINC00460 was significantly upregulated in NSCLC tissues and cell lines, and particularly negatively correlated with the overall survival (OS). According to the in vitro experimental results, LINC00460 knockdown inhibited the proliferation of A549 cells, but promoted their apoptosis. Dual-Luciferase reporter assay results revealed that miR-539 was directly targeted by LINC00460 and involved in the LINC00460-mediated proliferation of A549 cells. CONCLUSIONS: LINC00460 is overexpressed in NSCLC tissues and can promote the growth of NSCLC cells by targeting miR-539.

TAp63alpha indirectly regulates a cutaneous HPV promoter through complex formation with Jun family members.

The p63alpha isoforms of the p53 family have been demonstrated to play a crucial role in the development and differentiation of the skin. We show that expression of the TAp63alpha isoform leads to an upregulation of the cutaneous papillomavirus HPV 20 promoter, which is increased at least three-fold when c-Jun is co-expressed, in contrast to a minimal increase in activity in the presence of c-Jun alone. Co-expression of TAp63alpha with JunB or JunD, respectively, and in combination, leads to a reduction in the viral promoter activation measured by the expression of TAp63alpha alone. JunB and JunD also inhibits the additive effect exerted on the TAp63alpha activation by c-Jun. Co-immunoprecipitation assays demonstrate a complex formation of c-Jun, JunB and JunD with TAp63alpha through the SAM domain mediating protein-protein interactions, which is characteristic for p63alpha. Co-expression of p53 mutant R248W not only downregulates the differential modulation of the viral promoter by TAp63alpha alone and in the presence of the Jun family members, but leads to a reduction in the protein levels of the overexpressed c-Jun, JunB, JunD, as well as TAp63alpha. This model system provides insight into yet unknown pathways through which TAp63alpha and Jun may cooperate in the pathogenesis of HPV associated cutaneous lesions.