miR-101-3p sensitizes lung adenocarcinoma cells to irradiation via targeting BIRC5.

Lung adenocarcinoma (LUAD) has been considered as the most common cause of cancer-associated mortality. Radiotherapy resistance is one of the main reasons for LUAD treatment failure. The microRNA (miR)-101-3p has been previously reported to function as a tumor suppressor in several types of cancer, including LUAD. The present study aimed to explore the role and mechanism of miR-101-3p on radioresistance of lung adenocarcinoma cells through bioinformatics analysis and biological experiments. Based on the analysis of Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) data, it was demonstrated that the expression of miR-101-3p was low in LUAD tissues compared with normal lung tissues and was associated with poor prognosis of patients with LUAD. The results of the CCK-8 assay, colony formation assay, immunofluorescence staining, caspase-3 activity assay and western blotting demonstrated that miR-101-3p overexpression sensitized LUAD cells to ionizing radiation by decreasing the abilities of LUAD cell proliferation, colony formation, DNA damage repair and increasing caspase-3 activity and apoptosis of LUAD cells following ionizing radiation. Furthermore, according to bioinformatics analysis and luciferase assay, baculoviral IAP repeat containing 5 (BIRC5) was identified as a direct target of miR-101-3p. Increased BIRC5 expression reversed the miR-101-3p-mediated increase in LUAD cell radiotherapy sensitivity. Taken together, the results of the present study demonstrated that miR-101-3p may be considered as a potential target that can enhance LUAD cell sensitivity to radiotherapy, which may provide a new strategy to improve therapy in patients with LUAD.

Meng X ，Sun Y ，Liu S ，Mu Y ... -  《-》

The LncRNA NEAT1 Accelerates Lung Adenocarcinoma Deterioration and Binds to Mir-193a-3p as a Competitive Endogenous RNA.

Long noncoding RNAs (lncRNAs) contribute to the development of multiple malignant tumors. Here, we focused on the biological function and underlying molecular mechanism of an lncRNA, nuclear-enriched abundant transcript 1 (NEAT1), in lung adenocarcinoma (LUAD). In vitro experiments were conducted to determine the biological effects of NEAT1 in LUAD cells. A luciferase activity reporter assay was performed to corroborate the interaction between NEAT1 and miR-193a-3p. Data from Gene Expression Omnibus (GEO), Oncomine, The Cancer Genome Atlas (TCGA), and our in-house reverse transcription quantitative PCR (RT-qPCR) were combined to examine the expression of NEAT1 and miR-193a-3p in LUAD. To further explore the regulatory mechanism of NEAT1, we searched for putative target genes of miR-193a-3p from 12 online prediction databases and determined genes positively correlated with NEAT1 as candidate targets. Furthermore, we analyzed the expression of these selected genes using data from TCGA. In vitro experiments showed that knockdown of NEAT1 in LUAD cells markedly restrained cell proliferation, invasion, and migration and stimulated cell apoptosis. The dual-luciferase reporter assay demonstrated that miR-193a-3p directly targeted NEAT1 at its 3'-UTR. We then detected NEAT1 and miR-193a-3p in LUAD cells and normal lung epithelial cells and discovered high expression of NEAT1 and low expression of miR-193a-3p in LUAD cell lines. Simultaneously, the pooled results from the GEO, Oncomine, TCGA, and in-house RT-qPCR showed that the NEAT1 expression increased while the miR-193a-3p expression decreased in LUAD tissues versus normal lung tissues. Furthermore, the USF1 gene was not only upregulated in LUAD, but also positively correlated with NEAT1, suggesting that NEAT1 may function as a ceRNA to sponge miR-193a-3p and abrogate the inhibitory effect of miR-193a-3p on USF1. Our findings indicate that NEAT1 plays important roles in the occurrence and progression of LUAD. It may exert its role by acting as a ceRNA to regulate miR-193a-3p.

Xiong DD ，Li ZY ，Liang L ，He RQ ，Ma FC ，Luo DZ ，Hu XH ，Chen G ... -  《-》

Long noncoding RNA FBXL19-AS1 induces tumor growth and metastasis by sponging miR-203a-3p in lung adenocarcinoma.

The pivotal roles of long noncoding RNAs have been reported in various cancers. Recently, FBXL19-AS1 was proposed to be involved in tumor progression. However, its role in lung adenocarcinoma (LUAD) remains elusive. In this study, we observed that FBXL19-AS1 was significantly upregulated in LUAD tissues and high FBXL19-AS1 expression in LUAD was associated with a poor prognosis. Nevertheless, miR-203-3p showed the opposite effect. Moreover, cell viability and apoptosis analysis revealed that FBXL19-AS1 knockdown could arrest LUAD cells in G0/G1 phase and inhibit cell proliferation, migration and invasion in vitro and inhibited LUAD tumor progress in vivo. Mechanistically, we identified FBXL19-AS1 could act as a miR-203a-3p sponge using dual-luciferase reporter assay. In addition, we demonstrated that downregulation of miR-203a-3p reversed growth inhibition of LUAD cells caused by FBXL19-AS1 knockdown. Finally, FBXL19-AS1/miR-203a-3p axis was found to associate with baculoviral IAP repeat-containing protein 5.1-A-like (survivin), distal-less homeobox 5, E2F transcription factor 1, and zinc finger E-box binding homeobox 2 to regulate metastasis in LUAD cells. This study reveals a significance and mechanism of FBXL19-AS1 in LUAD proliferation and metastasis and offers a potential prognostic marker and a therapeutic target for patients with LUAD.

Wang L ，Zhang X ，Liu Y ，Xu S ... -  《-》

MicroRNA-147b promotes lung adenocarcinoma cell aggressiveness through negatively regulating microfibril-associated glycoprotein 4 (MFAP4) and affects prognosis of lung adenocarcinoma patients.

Lung adenocarcinoma (LUAD) is widely known as the leading cause of death in patients with lung cancer. Extensive evidence has determined that microRNAs (miRNAs) exert critical effects on various biological processes in tumorigenesis. microRNA-147b (miR-147b) has been reported to serve as an oncogenic molecule in colorectal cancer and hepatocellular carcinoma, however, its prognostic value and biological effect in LUAD remain rare. miR-147b and microfibril-associated glycoprotein 4 (MFAP4) data were collected from The Cancer Genome Atlas (TCGA) database to determine their expression levels in LUAD tissues. Kaplan-Meier method was used to plot the overall survival curves for the prognostic power of miR-147b and MFAP4 identification. Chi-square test was utilized to demonstrate the association between clinical characteristics and miR-147b or MFAP4 in LUAD. Luciferse reporter assay was implemented to identify the correlation between miR-147b and MFAP4. The mRNA and protein levels were detected by qRT-PCR and western blotting, respectively. To explore the effects of miR-147b and its potential mechanism in LUAD, cell counting kit 8 (CCK-8), colony formation and transwell assays were performed in LUAD cells with abnormal expression of miR-147b or/and MFAP4. Our results showed that miR-147b was up-regulated in LUAD tissues and cell lines, which induced poor outcome. Conversely, MFAP4, the putative target gene of miR-147b, was down-regulated in LUAD. The expression of MFAP4 in LUAD cells was negatively regulated by miR-147b. Results of experiments in vitro revealed that miR-147b could promote cell proliferation, colony formation, invasion and migration, while up-regulation of MFAP4 suppressed the impacts of miR-147b on cell malignant aggressiveness in A549 and Calu-3 cells. In conclusion, these findings determined that miR-147b contributed to the progression of LUAD via targeting MFAP4. Thus, understanding the potential mechanism of miR-147b/MFAP4 may improve the treatment of cancers, especially LUAD.

Feng YY ，Liu CH ，Xue Y ，Chen YY ，Wang YL ，Wu XZ ... -  《-》

Downregulated miR-144-3p contributes to progression of lung adenocarcinoma through elevating the expression of EZH2.

The intention of our study was to investigate the relationship between miR-144-3p and EZH2 as well as the effects of their interaction on cell propagation and invasiveness in lung adenocarcinoma (LUAD). The expression levels of miR-144-3p and EZH2 in LUAD tissues and normal tissues were determined by qRT-PCR. The dual-luciferase reporter assay was utilized to validate the targeting relationship between miR-144-3p and EZH2. MTT assay and colony formation assay were performed to evaluate the viability and propagation of LUAD cells, while the effects of miR-144-3p and EZH2 on LUAD cell invasiveness were confirmed by transwell assay. Protein expression levels of VEGFA, MMP2, and MMP9 were measured by Western blot. Furthermore, xenograft tumor models were established to verify the effects of miR-144-3p on tumor formation and EZH2, VEGFA, MMP2 and MMP9 expressions in vivo. miR-144-3P was downregulated in LUAD tissues, and overexpression of miR-144-3p inhibited propagation and invasiveness of LUAD cells. EZH2 was a target of miR-144-3p and was highly expressed in LUAD cells. Knockdown of EZH2 could suppress the propagation and invasion of LUAD cells. Increased miR-144-3p expression exerted an inhibitory effect on LUAD tumor formation in vivo. Overexpression of miR-144-3p impeded the propagation and invasiveness of LUAD cells by targeting EZH2.

Liu C ，Yang Z ，Deng Z ，Zhou Y ，Gong Q ，Zhao R ，Chen T ... -  《Cancer Medicine》