MiR-193a-3p is an Important Tumour Suppressor in Lung Cancer and Directly Targets KRAS.

MicroRNAs (miRNAs) have emerged as major regulators of tumour development and progression in non-small cell lung cancer (NSCLC). However, the role of miR-193a-3p in NSCLC is still unclear. Quantitative RT-PCR was used to detect miR-193a-3p expression levels in NSCLC tumour tissues. CCK8, EdU and cell migration assays were performed to analyse the biological functions of miR-193a-3p in NSCLC cells. Luciferase reporter assays were used to validate the bioinformatics-predicted target genes of miR-193a-3p. Western blotting and RNA/DNA interference carried out to evaluate the association between miR-193a-3p and KRAS. miR-193a-3p expression was decreased in the NSCLC tumour tissues. We investigated the biological effects of miR-193a-3p both in vivo and in vitro and found that enforced expression of miR-193a-3p inhibited tumour formation and suppressed cell proliferation and cell migration. KRAS was found to be a potential target of miR-193a-3p, and dual luciferase reporter assays showed that miR-193a-3p directly binds to the 3'-untranslated region (3'-UTR) of KRAS mRNA. In addition, we found that changing the expression of KRAS had the opposite results to those induced by miR-193a-3p in the NSCLC cells. Importantly, simultaneous overexpression of miR-193a-3p and KRAS could counteract the effects of both on cellular functions. These findings highlight an important role for miR-193a-3p as a tumour suppressor in NSCLC pathogenesis via the regulation of KRAS expression.

Fan Q ，Hu X ，Zhang H ，Wang S ，Zhang H ，You C ，Zhang CY ，Liang H ，Chen X ，Ba Y ... -  《-》

Downregulation of N-Acetylglucosaminyltransferase GCNT3 by miR-302b-3p Decreases Non-Small Cell Lung Cancer (NSCLC) Cell Proliferation, Migration and Invasion.

GCNT3 is a member of N-acetylglucosaminyltransferase family involved with mucin biosynthesis. GCNT3 aberrant expression is known to promote the progression of several human cancers. However, its role in tumorigenesis and the progression of non-small cell lung cancer (NSCLC) has not been well-characterized. Our study investigated the functional mechanisms of GCNT3 regulated by microRNAs (miRNAs) in NSCLC. The differential expression of mRNAs in NSCLC tissues and matched adjacent non-cancerous lung tissues from patients in Xuanwei, Yunnan province, China, was screened via mRNA microarray. The expression of GCNT3 and its correlation with NSCLC progression was measured in 92 paired tumor tissues and adjacent normal tissues. The functions of GCNT3 in NSCLC cells and its underlying mechanisms were measured using siRNA and GCNT3-expression vectors. The miRNA immunoprecipitation (miRIP) method was used to identify the miRNAs targeting GCNT3. The protein were measured using western blot assay, and the mRNAs were measured by quantitative real-time PCR (qRT-PCR) assay. Cell proliferation was measured using Cell Counting Kit-8 (CCK-8) and a colony forming assays; cell migration and invasion assays were performed using 24-well Transwell chambers with 8-μm pores filter, and analyses of the cell cycle and apoptosis were performed via flow cytometric analysis. The dual luciferase reporter assay was performed to confirm whether GCNT3 gene was a direct target of miR-302b-3p. GCNT3 was found to be highly expressed in both NSCLC tissues and cell lines, and higher expression correlated significantly with advanced tumor-node-metastasis (TNM) stage, positive lymph node metastasis, and poor overall survival. Knockdown of GCNT3 inhibited the proliferation, migration and invasion ability of NSCLC cells, while overexpression facilitated these activities. Further mechanistic experiments using miRIP and dual luciferase reporter assays revealed that GCNT3 was a direct target of miR-302b-3p. Low expression of miR-302b-3p was found in NSCLC cells and negatively correlated with GCNT3 levels, while miR-302b-3p overexpression inhibited the proliferation, migration and invasion of NSCLC cells. Co-transfection with miR-302b-3p and the expression vector of GCNT3 abrogated the effects of mir-302b-3p, confirming that miR-302b-3p inhibited NSCLC progression by targeting GCNT3. Western blotting revealed that E-cadherin, N-cadherin, vimentin, p-Erk and cyclin D1 were downstream molecules of miR-302b-3p/GCNT3 pathway. miR-302b-3p/GCNT3 axis regulated cell proliferation, migration, and invasion by activating the Erk signaling pathway and epithelial-mesenchymal transition (EMT), which was identified as a potential therapeutic target for NSCLC.

Li Q ，Ran P ，Zhang X ，Guo X ，Yuan Y ，Dong T ，Zhu B ，Zheng S ，Xiao C ... -  《-》

MiR-106b-5p Promotes Proliferation and Inhibits Apoptosis by Regulating BTG3 in Non-Small Cell Lung Cancer.

MicroRNAs have been validated to play a crucial role in tumorigenesis of non-small cell lung cancer (NSCLC). Although miR-106b-5p has been reported to play a vital role in various malignancies the physiological function of miR-106b-5p in NSCLC still remain unknown. In this study, we investigated the role of miR-106b-5p in NSCLC. Quantitative real-time polymerase chain reaction was conducted to estimate the expression of miR-106b-5p and BTG3 in both NSCLC tissues and cell lines. The effects of miR-106b-5p on proliferation were determined in vitro using CCK-8 proliferation assays, 5-ethynyl-2'-deoxyuridine (EdU) incorporation, colony formation assays and cell-cycle assays and the in vivo effects were evaluated by a mouse tumorigenicity model. Cell apoptosis and cell cycle was investigated by flow cytometric analysis in vitro. The molecular mechanism underlying the relevance between miR-106b-5p and BTG3 was confirmed by luciferase assay and western blot. In current study, we found a relatively higher miR-106b-5p and lower BTG3 expression in NSCLC specimens and cell lines. BTG3 was verified as a direct target of miR-106b-5p by luciferase assay. In vitro, over-expression of miR-106b-5p promoted proliferation and inhibited apoptosis by down-regulating BTG3 expression. In vivo, miR-106b-5p promoted xenograft tumor formation. Our findings revealed for the first time that miR-106b-5p plays a tumorigenesis role in NSCLC progression by down-regulating BTG3 expression, which may lead to a novel insight to the potential biomarker and novel therapeutic strategies for NSCLC patients.

Wei K ，Pan C ，Yao G ，Liu B ，Ma T ，Xia Y ，Jiang W ，Chen L ，Chen 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 ... -  《-》

miR-216b Post-Transcriptionally Downregulates Oncogene KRAS and Inhibits Cell Proliferation and Invasion in Clear Cell Renal Cell Carcinoma.

Increasing evidence has shown that miR-216b plays an important role in human cancer progression. However, little is known about the function of miR-216b in renal cell carcinoma. The expression levels of miR-216b in renal cell carcinoma tissues and cell lines were examined by qRT-PCR. The biological role of miR-216b in renal cell carcinoma proliferation and/or metastasis was examined in vitro and in vivo. The target of miR-216b was identified by a dual-luciferase reporter assay. The expression level of KRAS protein was measured by western blotting. The expression of miR-216b was downregulated in clear cell renal cell carcinoma (ccRCC) cell lines and specimens compared to the adjacent normal tissues. Furthermore, miR-216b can bind to the 3'untranslated region (UTR) of KRAS and inhibit the expression of KRAS through translational repression. The in vitro study revealed that miR-216b attenuated ccRCC cell proliferation and invasion. Furthermore, in vivo study also showed that miR-216b suppressed tumor growth. MiR-216b exerted its tumor suppressor function through inhibiting the KRAS-related MAPK/ERK and PI3K/AKT pathways. Our findings provide, for the first time, significant clues regarding the role of miR-216b as a tumor suppressor by targeting KRAS in ccRCC.

Wang Y ，Dong D ，Jiang S ，Zhang E ，Zheng W ，Mao L ，Li W ，Zhou J ，Fan L ，Cheng R ，Li Z ，Fang Z ，Gui Y ，Li X ... -  《-》