lincRNA HOTAIR as a novel promoter of cancer progression

The Role of lncRNAs in the Stem Phenotype of Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma is one of the deadliest tumors. This neoplasia is characterized by an important cellular and phenotypic heterogeneity. In particular, it has been shown that at least two subtypes can be found: basal-like, which presents stem-like properties, and classical. Cancer stem cells have been isolated and characterized from these tumors, showing their dependance on general and tissue-specific stem transcription factors and signaling pathways. Nevertheless, little is known about their tissue microenvironment and cell non-autonomous regulators, such as long-non-coding RNAs. (lncRNAs). In this review, we summarize the current knowledge about the positive and negative effects of lncRNAs in the stemness phenotype of pancreatic ductal adenocarcinoma cancer (PDAC).

Comprehensive analysis of ceRNA network related to lincRNA in glioblastoma and prediction of clinical prognosis

BACKGROUND

Long intergenic non-coding RNAs (lincRNAs) are capable of regulating several tumours, while competitive endogenous RNA (ceRNA) networks are of great significance in revealing the biological mechanism of tumours. Here, we aimed to study the ceRNA network of lincRNA in glioblastoma (GBM).

METHODS

We obtained GBM and normal brain tissue samples from TCGA, GTEx, and GEO databases, and performed weighted gene co-expression network analysis and differential expression analysis on all lincRNA and mRNA data. Subsequently, we predicted the interaction between lincRNAs, miRNAs, and target mRNAs. Univariate and multivariate Cox regression analyses were performed on the mRNAs using CGGA data, and a Cox proportional hazards regression model was constructed. The ceRNA network was further screened by the DEmiRNA and mRNA of Cox model.

RESULTS

A prognostic prediction model was constructed for patients with GBM. We assembled a ceRNA network consisting of 18 lincRNAs, 6 miRNAs, and 8 mRNAs. Gene Set Enrichment Analysis was carried out on four lincRNAs with obvious differential expressions and relatively few studies in GBM.

CONCLUSION

We identified four lincRNAs that have research value for GBM and obtained the ceRNA network. Our research is expected to facilitate in-depth understanding and study of the molecular mechanism of GBM, and provide new insights into targeted therapy and prognosis of the tumour.

Non-coding RNAs: the new central dogma of cancer biology

The central dogma of molecular biology states that the functions of RNA revolve around protein translation. Until the last decade, most researches were geared towards characterization of RNAs as intermediaries in protein translation, namely, messenger RNAs (mRNAs) as temporary copies of genetic information, ribosomal RNAs (rRNAs) as a main component of ribosome, or translators of codon sequence (tRNAs). The statistical reality, however, is that these processes account for less than 2% of the genome, and insufficiently explain the functionality of 98% of transcribed RNAs. Recent discoveries have unveiled thousands of unique non-coding RNAs (ncRNAs) and shifted the perception of them from being "junk" transcriptional products to "yet to be elucidated"-and potentially monumentally important-RNAs. Most ncRNAs are now known as key regulators in various networks in which they could lead to specific cellular responses and fates. In major cancers, ncRNAs have been identified as both oncogenic drivers and tumor suppressors, indicating a complex regulatory network among these ncRNAs. Herein, we provide a comprehensive review of the various ncRNAs and their functional roles in cancer, and the pre-clinical and clinical development of ncRNA-based therapeutics. A deeper understanding of ncRNAs could facilitate better design of personalized therapeutics.

lncRNA-uc003opf.1 rs11752942 A>G polymorphism decreases neuroblastoma risk in Chinese children

Recent studies have revealed that long non-coding RNAs (lncRNAs) play critical roles in the tumorigenesis and proliferation of human cancer. Several polymorphisms of lncRNAs have been found to be involved in the risk of neuroblastoma (NB). However, studies on the relationship between polymorphisms in lncRNA exons and NB are infrequent. We evaluated the association between rs11752942 A > G polymorphism in lnc-RNA-uc003opf.1 exon and neuroblastoma susceptibility by performing a hospital-based study with 275 patients and 531 controls. Odds ratios (ORs) and 95% confidence intervals (CIs) assessed by using logistic regression models were used to determine the strength of the association. We found that the rs11752942 G allele is significantly associated with decreased neuroblastoma risk (AG vs. AA: adjusted OR = 0.72, 95% CI = 0.53-0.98, P = 0.038; and AG/GG vs. AA: adjusted OR = 0.74, 95% CI = 0.55-0.99, P = 0.045) after adjusting for age and gender. This association was more prominent in females, subjects with tumor in the mediastinum or early-stage. Furthermore, the expression quantitative trait locus analysis indicated that rs11752942 G was associated with decreased expression of its neighboring gene LRFN2 mRNA. These results indicate that lncRNA-uc003opf.1 may be a novel potentially functional lncRNA that may be used as a predictive marker, for it might contribute to decreased neuroblastoma risk.

Genetic Variants of HOTAIR Associated With Colorectal Cancer Susceptibility and Mortality

In colorectal carcinogenesis, the unique molecular and genetic changes that occur within cells result in specific CRC phenotypes. The involvement of the long non-coding RNA, HOTAIR, in cancer development, progression, and metastasis is well-established. Various studies have reported on the contribution of HOTAIR to cancer pathogenesis. Therefore, we selected four HOTAIR polymorphisms (rs7958904G>C, rs1899663G>T, rs4759314A>G, and rs920778T>C) to evaluate the association of each variant with CRC prevalence and prognosis. We conducted a case–control study of 850 individuals to identify the genotype frequencies of each polymorphism. The study population included 450 CRC patients and 400 control individuals that were randomly selected following a health screening. Notably, rs7958904 and rs1899663, their hetero genotype, and the dominant model were significantly different when compared to the healthy control group (rs7958904; AOR = 1.392, 95% CI = 1.052–1.843, P = 0.021). To evaluate the effect of HOTAIR polymorphisms on the survival rate, we analyzed patient mortality and relapse occurrence within 3 and 5 years with Cox-regression analysis. The rs7958904 CC polymorphism mortality rate was significantly higher than the GG polymorphism mortality rate (adjusted HR = 2.995, 95% CI = 1.189–7.542, P = 0.021). In addition, the rs920778 CC genotype was significantly different than the TT genotype (adjusted HR = 3.639, 95% CI = 1.435–9.230, P = 0.007). In addition, this study confirmed that genetic variants of HOTAIR alter the mRNA expression level (P < 0.01). We suggest that HOTAIR rs7958904G>C which is associated with CRC prevalence and mortality is a potential biomarker for CRC. The association between HOTAIR gene polymorphisms and CRC prevalence were reported for the first time.

The rs12826786 in HOTAIR lncRNA Is Associated with Risk of Autism Spectrum Disorder

Autism spectrum disorder (ASD) encompasses a group of neurodevelopmental disorders with complex pattern of inheritance. Several single nucleotide polymorphisms (SNPs) within coding or non-coding regions of genome have been associated with risk of this disorder. In the current study, we genotyped rs12826786, rs1899663, and rs4759314 SNPs within HOX transcript antisense RNA (HOTAIR) in 427 ASD cases and 430 normally developed children. The rs12826786 was associated with ASD in allelic (T vs. C: OR (95% CI) = 1.29 (1.07-1.57), adjusted P value = 0.03) and recessive (TT vs. TC + CC: OR (95% CI) = 1.60 (1.10-2.32), adjusted P value = 0.04) models. However, the other SNPs were not associated with ASD in any inheritance model. No estimated haplotype within HOTAIR was associated with risk of ASD in the assessed population. Based on the results of the current investigation, the rs12826786 can be regarded as a risk locus for ASD in Iranian population.

Exploring the mechanisms behind long noncoding RNAs and cancer

Over the past decade, long noncoding RNAs (lncRNAs) have been identified as significant players in gene regulation. They are often differentially expressed and widely-associated with a majority of cancer types. The aberrant expression of these transcripts has been linked to tumorigenesis, metastasis, cancer stage progression and patient survival. Despite their apparent link to cancer, it has been challenging to gain a mechanistic understanding of how they contribute to cancer, partially due the difficulty in discriminating functional RNAs from other noncoding transcription events. However, there are several well-studied lncRNAs where specific mechanisms have been more clearly defined, leading to new discoveries into how these RNAs function. One major observation that has come to light is the context-dependence of lncRNA mechanisms, where they often have unique function in specific cell types and environment. Here, we review the molecular mechanisms of lncRNAs with a focus on cancer pathways, illustrating a few informative examples. Together, this type of detailed insight will lead to a greater understanding of the potential for the application of lncRNAs as targets of cancer therapies and diagnostics.

Noncoding Rnas Emerging as Novel Biomarkers in Pancreatic Cancer

Noncoding RNAs play important regulatory roles in diverse biological processes and their misregulation might lead to different diseases, including cancer. Previous studies have reported the evolving role of miRNAs as new potential biomarkers in cancer diagnosis, prognosis, as well as predictive biomarkers of chemotherapy response or therapeutic targets. In this review, we outline the involvement of noncoding RNA in pancreatic cancer, providing an overview of known miRNAs in its diagnosis, prognosis and chemoresistance. In addition, we discuss the influence of non-coding RNAs in the metastatic behavior of pancreatic cancer, as well as the role of diet in epigenetic regulation of non-coding RNAs in cancer, which can, in turn, lead the development of new prevention's techniques or novel targets for cancer therapy.

HOTAIR Long Non-coding RNA: Characterizing the Locus Features by the In Silico Approaches

HOTAIR is an lncRNA that has been known to have an oncogenic role in different cancers. There is limited knowledge of genetic and epigenetic elements and their interactions for the gene encoding HOTAIR. Therefore, understanding the molecular mechanism and its regulation remains to be challenging. We used different in silico analyses to find genetic and epigenetic elements of HOTAIR gene to gain insight into its regulation. We reported different regulatory elements including canonical promoters, transcription start sites, CpGIs as well as epigenetic marks that are potentially involved in the regulation of HOTAIR gene expression. We identified repeat sequences and single nucleotide polymorphisms that are located within or next to the CpGIs of HOTAIR. Our analyses may help to find potential interactions between genetic and epigenetic elements of HOTAIR gene in the human tissues and show opportunities and limitations for researches on HOTAIR gene in future studies.

Deep Illumina sequencing reveals differential expression of long non-coding RNAs in hyperoxia induced bronchopulmonary dysplasia in a rat model

BACKGROUND

Bronchopulmonary dysplasia (BPD) in premature infants is a predominantly secondary occurrence to intrauterine inflammation/infection and postpartum mechanical ventilation; The purpose of this study is to explore the biological roles of lincRNA in the pathogenesis of BPD.

METHODS

Newborn rats were randomly assigned to hyperoxia (85% O2) or the control group: the normoxia group (21% O2). Lung tissues were collected on days 1-14. The BPD animal model was validated using HE staining, Masson staining, and real-time RT-PCR. Deep Illumina sequencing was used to reveal the differential expression of long non-coding RNAs in hyperoxia bronchopulmonary dysplasia rat models. KEGG and GO functions were predicted. Nine possible BPD-related target lincRNAs were verified by RTq-PCR.

RESULTS

The histopathologic changes in lung tissues manifested as hyperaemia, edema, hemorrhage, and inflammation cell infiltration after continuous exposure to hyperoxia for 3 days, and became aggravated after 7 days of hyperoxic exposure. The above lung tissue inflammatory manifestations were alleviated and taken over by pulmonary interstitia hyperplasia and fibrocyte proliferation after 14 days of hyperoxic exposure. The expressions of lincRNA differed between the hyperoxia bronchopulmonary dysplasia model group and the normoxia group. 1175 different lincRNAs were detected in the hyperoxia group and the normoxia group, of which 544 were up-regulated and 631 were down-regulated. 673 moleculars related to GO functions were enriched, including cell location and biological process. Pathway enrichment analysis showed that lincRNA was involved in 257 KEGG pathways. 9 lincRNA were validated in the sample, and the difference was statistically significant.

CONCLUSION

LincRNAs were identified differently between the BPD model and the normoxia group. Many target genes were involved in the developmental process, including cell component biogenesis, biological regulation, transcription regulator, and translation regulator. The BPD might be caused by the activation of the pathways of the EMC-receptor interaction, cytokine-cytokine receptor interaction, cell cycle, and cell adhesion molecules. The present study provides new insight into the pathogenesis mechanism of BPD.

Induction of a novel isoform of the lncRNA HOTAIR in Claudin-low breast cancer cells attached to extracellular matrix

Elevated overexpression of the lncRNA HOTAIR mediates invasion and metastasis in breast cancer. In an apparent paradox, we observed low expression of HOTAIR in the invasive Claudin‐low MDA‐MB‐231 and Hs578T cells in two‐dimensional culture (2D). However, HOTAIR expression exhibited robust induction in laminin‐rich extracellular matrix‐based three‐dimensional organotypic culture (lrECM 3D) over that in 2D culture. Induction of HOTAIR required intact ECM signaling, namely integrin α2 and SRC kinase activity. Moreover, invasive growth was suppressed by HOTAIR‐specific siRNA. Induction of HOTAIR in lrECM 3D culture resulted from the activation of a novel isoform of HOTAIR (HOTAIR‐N) whose transcription is started from the first intron of the HOXC11 gene. The HOTAIR‐N promoter exhibited increased trimethylation of histone H3 lysine 4, a histone marker of active transcription, and binding of BRD4, a reader of transcriptionally active histone markers. Inhibition of BRD4 substantially reduced the expression of HOTAIR in lrECM 3D culture. In summary, our results indicate that HOTAIR expression is activated by BRD4 binding to a novel HOTAIR‐N promoter in Claudin‐low breast cancer cells that are attached to ECM. Induction of HOTAIR is required for invasive growth of Claudin‐low breast cancer cells in lrECM 3D culture.

RNA sequencing identifies novel non-coding RNA and exon-specific effects associated with cigarette smoking

BACKGROUND

Cigarette smoking is the leading modifiable risk factor for disease and death worldwide. Previous studies quantifying gene-level expression have documented the effect of smoking on mRNA levels. Using RNA sequencing, it is possible to analyze the impact of smoking on complex regulatory phenomena (e.g. alternative splicing, differential isoform usage) leading to a more detailed understanding of the biology underlying smoking-related disease.

METHODS

We used whole-blood RNA sequencing to describe gene and exon-level expression differences between 229 current and 286 former smokers in the COPDGene study. We performed differential gene expression and differential exon usage analyses using the voom/limma and DEXseq R packages. Samples from current and former smokers were compared while controlling for age, gender, race, lifetime smoke exposure, cell counts, and technical covariates.

RESULTS

At an adjusted p-value <0.05, 171 genes were differentially expressed between current and former smokers. Differentially expressed genes included 7 long non-coding RNAs that have not been previously associated with smoking: LINC00599, LINC01362, LINC00824, LINC01624, RP11-563D10.1, RP11-98G13.1, AC004791.2. Secondary analysis of acute smoking (having smoked within 2-h) revealed 5 of the 171 smoking genes demonstrated an acute response above the baseline effect of chronic smoking. Exon-level analyses identified 9 exons from 8 genes with significant differential usage by smoking status, suggesting smoking-induced changes in isoform expression.

CONCLUSIONS

Transcriptomic changes at the gene and exon levels from whole blood can refine our understanding of the molecular mechanisms underlying the response to smoking.

Long intergenic non-coding RNA GALMD3 in chicken Marek's disease

Long intergenic non-coding RNAs (lincRNAs) are transcribed from non-coding DNA sequences. Studies have revealed that aberrant expressions of lincRNAs are associated with various types of cancers and neurological disorders. Marek's disease (MD) is a highly contagious T-cell lymphoid neoplasia of chicken induced by Marek's disease virus (MDV). In this study, we first identified and validated linc-GALMD3 highly expressed in MDV-infected CD4+ T cells by RNA-Seq and qRT-PCR. By RNA-Seq analysis in MDCC-MSB1 cells after loss of function of linc-GALMD3 by shRNA, we found that linc-GALMD3 could positively cis-regulate its downstream gga-miR-223 gene expression. In contrast, it could trans-regulate the 748 differentially expressed genes (FDR < 0.01) that were mainly enriched into mitochondrial structure and cell cycle processes using GO analysis. Of these, the most significantly expressed gene EPYC might cause iris lesion in MD. The other eight genes, NDUFA4, NDUFB6, NDUFV1, NDUFS8, SDHB, UQCRC1, UQCRC2, and COX7A2, actively participated in oxidative phosphorylation in mitochondrial dysfunction and cell death. Most importantly, we found that the MDV replication was repressed when linc-GALMD3 was knocked down in CEF cells. Our results suggested that linc-GALMD3 might be a critical regulator in chicken MD and could be used as a candidate-promising mark for MD prevention, diagnosis, and treatment.

Intersecting transcriptomic profiling technologies and long non-coding RNA function in lung adenocarcinoma: discovery, mechanisms, and therapeutic applications

Previously thought of as junk transcripts and pseudogene remnants, long non-coding RNAs (lncRNAs) have come into their own over the last decade as an essential component of cellular activity, regulating a plethora of functions within multicellular organisms. lncRNAs are now known to participate in development, cellular homeostasis, immunological processes, and the development of disease. With the advent of next generation sequencing technology, hundreds of thousands of lncRNAs have been identified. However, movement beyond mere discovery to the understanding of molecular processes has been stymied by the complicated genomic structure, tissue-restricted expression, and diverse regulatory roles lncRNAs play. In this review, we will focus on lncRNAs involved in lung cancer, the most common cause of cancer-related death in the United States and worldwide. We will summarize their various methods of discovery, provide consensus rankings of deregulated lncRNAs in lung cancer, and describe in detail the limited functional analysis that has been undertaken so far.

HOTAIR in Relation to Epithelial-Mesenchymal Transition and Cancer Stem Cells in Molecular Subtypes of Endometrial Cancer

Background

Endometrial cancer (EC) is a hormone-related disease, showing highly diverse features of ER/PR/HER2 status-based molecular subtypes. Long noncoding RNA (lncRNA) HOX antisense intergenic RNA (HOTAIR) has recently emerged as a key molecule in many cancers, triggering epithelial-mesenchymal transition (EMT)–mediated cancer stem cell (CSC) formation, but little is known about its significance in EC. Thus, we aimed to investigate the clinical significance of HOTAIR itself in different molecular subtypes of EC and possible links between HOTAIR, EMT and CSC-related markers.

Methods

The study group included 156 consecutive, stage I-IV EC patients treated between 2000 and 2010. ER, PR and HER2 protein expression were examined by immunohistochemistry (IHC) on tissue microarrays. RT-qPCR was used to analyze the expression levels of HOTAIR, EMT-related genes – SNAIL and SLUG – and the CSCs marker CD133.

Results

Molecular subtypes, defined as ER/PR+HER2+, ER/PR+HER2-, ER-PR-HER2+ and ER-PR-HER2-, occurred in 40.2%, 52.3%, 4.7% and 1.9% of cases, respectively. The expression of HOTAIR did not differ between the subtypes, but high HOTAIR expression correlated with shorter overall survival (p = 0.04) in the entire group. The expression levels of HOTAIR, SNAIL, SLUG and CD133 were similar in defined EC molecular subtypes.

Conclusions

Our data do not confirm the role of HOTAIR in EMT-mediated CSC formation in EC. Neither does the diversity of EC molecular subtypes influence these processes. But HOTAIR expression could serve as an independent prognostic factor in EC. The clinical importance of the above discoveries requires further studies.

Genetic variants of lncRNA HOTAIR and risk of epithelial ovarian cancer among Chinese women

Ovarian cancer is one of the common female malignant tumors globally. However, exactly mechanism of ovarian cancer remained unknown. HOTAIR, a lncRNA in the mammalian HOXC locus, has been fully explored for its genetic variants, expression level and carcinogenesis, development and progression of multiple cancers, except for ovarian cancer. In this study, we hypothesized that abnormal expression of HOTAIR and common variants of HOTAIR are associated with risk of Epithelial ovarian cancer (EOC). We first evaluated the HOTAIR levels in 100 paired tissues of EOC patients and corresponding normal tissues. Results showed that the expression level of HOTAIR in EOC tissues was significantly higher than that in corresponding normal tissues. Then the genotyping analyses of HOTAIR gene was conducted in a Chinese population. The results indicated that rs4759314 and rs7958904 were significantly associated with EOC susceptibility. For rs4759314, the difference between the G allele (as the reference) and the A allele was statistically significant (adjusted OR, 1.34; 95% CI: 1.08–1.65; P = 6.8 × 10⁻³). For rs7958904, C allele was associated a significantly decreased EOC risk when compared with G allele (OR: 0.77; 95% CI: 0.67–0.89; P = 4.2 × 10⁻⁴). The study identified that HOTAIR variants could be a useful biomarker for the predisposition to EOC and for the early diagnosis of the disease.

Non-coding yet non-trivial: a review on the computational genomics of lincRNAs

Long intergenic non-coding RNAs (lincRNAs) represent one of the most mysterious RNA species encoded by the human genome. Thanks to next generation sequencing (NGS) technology and its applications, we have recently witnessed a surge in non-coding RNA research, including lincRNA research. Here, we summarize the recent advancement in genomics studies of lincRNAs. We review the emerging characteristics of lincRNAs, the experimental and computational approaches to identify lincRNAs, their known mechanisms of regulation, the computational methods and resources for lincRNA functional predictions, and discuss the challenges to understanding lincRNA comprehensively.

A functional HOTAIR rs12826786 C>T polymorphism is associated with breast cancer susceptibility and poor clinicopathological characteristics in a Turkish population: a hospital-based case-control study

Hox transcript antisense intergenic RNA (HOTAIR), a long non-coding RNA (lncRNA), is pervasively overexpressed and correlated with tumor invasion, progression, metastasis, and poor prognosis in various human cancers including breast cancer (BC) that plays a role as an oncogenic molecule. A common functional single-nucleotide polymorphism (SNP) (rs12826786 C>T) at the HOTAIR promoter has been reported to influence HOTAIR expression and gastric adenocarcinoma susceptibility, but relation of HOTAIR rs12826786 C>T polymorphism with BC susceptibility and clinicopathological characteristics has yet to be reported. To explore the association of the HOTAIR rs12826786 C>T polymorphism with the risk of BC in a Turkish population, a hospital-based case-control study was carried out consisting of 123 BC patients and 122 age-matched healthy controls. HOTAIR rs12826786 C>T polymorphism was determined by real-time polymerase chain reaction (PCR) using TaqMan assay. We found that women carrying TT genotype of HOTAIR rs12826786 C>T polymorphism had an increased risk of developing BC in both codominant (odds ratio (OR) = 2.24, 95 % confidence interval (CI) 1.05-4.81, P = 0.02) and recessive (OR = 2.49, 95 % CI 1.25-4.97, P = 0.008) inheritance models. Moreover, TT genotype of HOTAIR rs12826786 C>T polymorphism was significantly related with multiple clinicopathological characteristics concerned with worse BC progression such as advanced TNM stage (III and IV), larger tumor size (T3 and T4), and distant metastasis (M1), as well as poor histological grade (III) (P < 0.05). Because of our results put forward for the first time that TT genotype of HOTAIR rs12826786 C>T polymorphism might play crucial roles in genetic susceptibility and poor prognosis for BC in Turkish population, further independent studies are needed to confirm our results in a larger series, as well as in patients of distinct populations.

Next-Generation Sequencing Approaches in Cancer: Where Have They Brought Us and Where Will They Take Us?

Next-generation sequencing (NGS) technologies and data have revolutionized cancer research and are increasingly being deployed to guide clinicians in treatment decision-making. NGS technologies have allowed us to take an “omics” approach to cancer in order to reveal genomic, transcriptomic, and epigenomic landscapes of individual malignancies. Integrative multi-platform analyses are increasingly used in large-scale projects that aim to fully characterize individual tumours as well as general cancer types and subtypes. In this review, we examine how NGS technologies in particular have contributed to “omics” approaches in cancer research, allowing for large-scale integrative analyses that consider hundreds of tumour samples. These types of studies have provided us with an unprecedented wealth of information, providing the background knowledge needed to make small-scale (including “N of 1”) studies informative and relevant. We also take a look at emerging opportunities provided by NGS and state-of-the-art third-generation sequencing technologies, particularly in the context of translational research. Cancer research and care are currently poised to experience significant progress catalyzed by accessible sequencing technologies that will benefit both clinical- and research-based efforts.

Functions of lncRNA HOTAIR in lung cancer

Long non-coding RNAs (lncRNAs) govern fundamental biochemical and cellular processes. lncRNA HOX transcript antisense RNA (HOTAIR) represses gene expression through recruitment of chromatin modifiers. The expression of HOTAIR is elevated in lung cancer and correlates with metastasis and poor prognosis. Moreover, HOTAIR promotes proliferation, survival, invasion, metastasis, and drug resistance in lung cancer cells. Here we review the molecular mechanisms underlying HOTAIR-mediated aggressive phenotypes of lung cancer. We also discuss HOTAIR’s potential in diagnosis and treatment of lung cancer, as well as the challenges of exploiting HOTAIR for intervention of lung cancer.