Lung Cancer 85 (2014) 110–115 Contents lists available at ScienceDirect Lung Cancer jou rnal h om epa ge: www.elsevier.com/locate/lungcan Review Analysis of lncRNA expression profiles in non-small cell lung cancers (NSCLC) and their clinical subtypes  Jingcheng Yang a,1 , Jinyuan Lin a,1 , Tianxiao Liu a,1 , Ting Chen b , Shangling Pan c , Weiqiang Huang a,* , Shikang Li a,* a Department of Thoracic and Cardiovascular Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, China b Department of Management Information System, College of Computer and Information Engineering, Guangxi Teachers Education University, Nanning, China c Department of Pathophysiology, Guangxi Medical University, Nanning, China a r t i c l e i n f o Article history: Received 30 January 2014 Received in revised form 4 April 2014 Accepted 11 May 2014 Keywords: Non-small cell lung cancer Biomarker lncRNA Expression profiling Adenocarcinoma Squamous cell carcinoma a b s t r a c t Lung cancer is one of the most common human cancers worldwide. Among all lung cancer cases, non- small cell lung cancer (NSCLC) accounts for approximately 85%. Long non-coding RNAs (lncRNAs) are non-protein-coding transcripts that have been shown to play important roles in tumourigenesis and tumor progression. To reveal novel tumor-related lncRNAs in NSCLC and their associations with clinical subtypes, we herein identified 2935 probe sets mapped to lncRNAs on Affymetrix HG-U133 Plus 2.0 array with an lncRNA classification pipeline. We found 47 lncRNAs differentially expressed between normal lung tissues and tumor samples and 19 lncRNAs differed in expression between SCC and AC, two subtypes of NSCLC, after analyses of the gene expression profiles of five datasets downloaded from the gene expression omnibus (GEO) with a leave one dataset out validation process. The different lncRNA expression profiles between NSCLC and normal tissue and between the subtypes of NSCLC may have potential implications in the pathogenesis of this cancer. lncRNAs screening may be beneficial in the diagnosis, subclassification, and the personalized treatment of NSCLC. © 2014 Elsevier Ireland Ltd. All rights reserved. 1. Introduction lncRNA (long non-coding RNA) is an RNA molecule that is longer than 200 nucleotides which is not translated into a protein [1]. Many identified lncRNAs are transcribed by RNA polymerase II (RNA pol II). They mainly locate within nucleus or cytosolic compartment [2]. lncRNAs can be further subcategorized into the following locus biotypes based on their location with respect to protein-coding genes: (1) sense, (2) antisense, (3) bidirectional, (4) intronic, and (5) intergenic [3]. They regulate gene expression through epigenetic regulation, splicing, imprinting, transcriptional regulation and subcellular transport [4]. Over the last few decades, researches have been focusing on the role of protein-coding genes  Disclaimers: The authors take full responsibility for the content of this publica- tion, confirming that it reflects their viewpoint and medical expertise. * Corresponding authors at: Department of Thoracic and Cardiovascular Surgery, The First Affiliated Hospital of Guangxi Medical University, 6 Shuangyong Road, Nan- ning 530021, Guangxi Zhuang Autonomous Region, China. Tel.: +86 13397705186; fax: +86 771 5352775. E-mail address: shikangli@hotmail.com (S. Li). 1 These authors contributed equally. in the pathogenesis of cancer [5], paying less attention to the possi- ble effects of lncRNAs. However, in recent years emerging evidence indicate that lncRNAs are dysregulated and play important roles in tumourigenesis and tumor progression [6]. Some of the regula- tory mechanisms of lncRNAs have been elucidated. For example, HOTAIR, an lncRNA locates in the HOXC locus on 12q13.13, was firstly described as having a fundamental role in human breast can- cer [7]. It binds to PRC2, silencing a portion of the HOXD locus, inducing H3 lysine 27 trimethylation, then remodeling the gene expression pattern of breast epithelial cells as does in embryonic fibroblasts [4,8]. lncRNA expression profiles are also altered in other types of cancers, including human prostate cancer, renal carcinoma, ovarian cancer, and human lung adenocarcinoma, raising the possi- bility that lncRNAs may become a promising diagnostic biomarker [9]. Lung cancer is one of the most common human cancers world- wide with considerable high morbility and mortality [10,11]. Among all lung cancer cases, non-small-cell lung cancer (NSCLC) accounts for approximately 85% [12] whose most effective ther- apy is complete lung resection plus appropriate chemotherapeutic strategy [13]. Nevertheless, several studies have observed different therapeutic responses due to specific cell types of NSCLC [14]. This http://dx.doi.org/10.1016/j.lungcan.2014.05.011 0169-5002/© 2014 Elsevier Ireland Ltd. All rights reserved.