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Background/aims 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. Methods 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. Results 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. Conclusion 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.

Dysregulated long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) play key roles in the development of human cancers. The lncRNA plasmacytoma variant translocation 1 (PVT1) is reported to be an oncogene in a variety of cancers. However, the roles of PVT1-5 and its related miRNAs in lung cancer are poorly understood. In this study, we found that PVT1-5 expression was significantly increased in lung cancer tissues and cell lines. By using biotin-labeled lncRNA-PVT1-5 probe for miRNA in vivo precipitation (miRIP) in lung cancer cells and dual-luciferase reporterassays, we identified that miR-126 was associated with lncRNA-PVT1-5. Furthermore, knockdown of lncRNA-PVT1-5 in cells could down-regulate the expression of SLC7A5, the target of oncogenic miR-126, resulting in the cell proliferation. Conversely, inhibiting the expression of miR-126 markedly increased the expression of SLC7A5 and alleviated cell proliferation inhibition. Thus, our results indicated that lncRNA-PVT1-5 may function as a competing endogenous RNA (ceRNA) for miR-126 to promote cell proliferation by regulating the miR-126/SLC7A5 pathway, suggesting that lncRNA-PVT1-5 plays a crucial role in lung cancer progression and lncRNA-PVT1-5/miR-126/SLC7A5 regulatory network may shed light on tumorigenesis in lung cancer.

// Fei Xie 1, * , Xudong Xiang 2, * , Qionglin Huang 1, * , Pengzhan Ran 1 , Yuncang Yuan 1 , Qian Li 1 , Guoxiang Qi 1 , Xiaopeng Guo 1 , Chunjie Xiao 1, ** , Shangyong Zheng 1, ** 1 School of Medicine, Yunnan University, Kunming, Yunnan 650091, P.R. China 2 Department of Thoracic Surgery, The Third Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650118, P.R. China * These authors have contributed equally to this work ** These two authors are co-corresponding authors Correspondence to: Chunjie Xiao, email: chjxiao@ynu.edu.cn Shangyong Zheng, email: shangyong@ynu.edu.cn Keywords: long non-coding RNA, lncRNA-BCAT1, β-catenin, tumor suppressor, colorectal cancer Received: September 23, 2016 Accepted: December 27, 2016 Published: February 17, 2017 ABSTRACT β-catenin plays a major role in tumor development and progression. The present study found that β-catenin was upregulated in 30 samples of colorectal cancer (CRC) tissue as compared to adjacent non-tumor tissues. Analysis of long non-coding RNA (lncRNA) expression profiles using the GSE18560 and GSE44097 datasets, which were generated via the Affymetrix plus 2.0 microarray platform and downloaded from the GEO database, revealed 20 differentially expressed lncRNAs following β-catenin knockdown. We focused on AK091631, a novel lncRNA, which we named lncRNA-β-catenin associated transcript 1 (LncRNA-BCAT1). lncRNA-BCAT1 expression was decreased in CRC tissues, and was negatively associated with β-catenin in both CRC tissues and cell lines. lncRNA-BCAT1 overexpression suppressed CRC cell growth and invasion by downregulating cyclin D1, c-Myc, and MMP-2. These results suggest that lncRNA-BCAT1 overexpression inhibits CRC cell growth and invasion via Wnt/β-catenin pathway blockade, and that lncRNA-BCAT1 is repressed by Wnt/β-catenin signaling. This evidence suggests that lncRNA-BCAT1 is a tumor suppressor and that lncRNA-BCAT1 may be an effective prognostic biomarker in CRC.

The eyes absent homologue 2 (EYA2) is a dual-functional transcription factor/phosphatase that plays a critical role in neoplasia. The precise effects of EYA2 remain elusive in non-small cell lung cancer (NSCLC). In the present study, we examined EYA2 expression in NSCLC cell lines and a normal pulmonary epithelial cell line. We found that EYA2 was aberrantly upregulated in the lung adenocarcinoma cells. Therefore, we studied the methylation status of the eya2 gene in a lung adenocarcinoma cell line, a normal pulmonary epithelial cell line and lung adenocarcinoma tissues. Furthermore, the eya2 gene was knocked down in lung adenocarcinoma cells via RNA interference to investigate the regulatory role of EYA2; specifically, cell proliferation, cell cycle distribution, apoptosis, migration and invasive capacities were assessed in tje EYA2‑knockdown cancer cells. The results showed that the aberrant hypomethylation and overexpression of the eya2 gene were associated with lung adenocarcinoma oncogenesis. In addition, inhibition of EYA2 expression suppressed tumour cell growth by altering the proliferation, cell cycle distribution, apoptosis, migration and invasive capacities of the cells. These findings demonstrated that EYA2 functions as a stimulant in lung adenocarcinoma pathogenesis and may facilitate the development of novel diagnostic targets and therapy strategies for lung adenocarcinoma.