Identification of an imprinted gene, Meg3/Gtl2 and its human homologue MEG3, first mapped on mouse distal chromosome 12 and human chromosome 14q

Human Long Noncoding RNA Regulation of Stem Cell Potency and Differentiation

Because of their capability of differentiation into lineage-specific cells, stem cells are an attractive therapeutic modality in regenerative medicine. To develop an effective stem cell-based therapeutic strategy with predictable results, deeper understanding of the underlying molecular mechanisms of stem cell differentiation and/or pluripotency maintenance is required. Thus, reviewing the key factors involved in the transcriptional and epigenetic regulation of stem cell differentiation and maintenance is important. Accumulating data indicate that long noncoding RNAs (lncRNAs) mediate numerous biological processes, including stem cell differentiation and maintenance. Here, we review recent findings on the human lncRNA regulation of stem cell potency and differentiation. Although the clinical implication of these lncRNAs is only beginning to be elucidated, it is anticipated that lncRNAs will become important therapeutic targets in the near future.

Long Noncoding RNAs as Diagnostic and Therapeutic Targets in Type 2 Diabetes and Related Complications

Protein-coding genes represent only a small fraction of the human genome. In the past, the majority of the genomic sequence has been considered transcriptionally silent, but recent large-scale studies have uncovered an array of functionally significant elements, including non-protein-coding transcripts, within these noncoding regions of the human genome. Long noncoding RNAs (lncRNAs), a class of noncoding transcripts with lengths >200 nucleotides, are pervasively transcribed in the genome and function as signals, decoys, guides, or scaffolds to regulate gene expression. More than 200 diseases have been associated with dysregulated or dysfunctional lncRNAs, and new associations continue to accumulate in the literature. The role of lncRNAs in the pathogenesis of type 2 diabetes mellitus and related complications has only recently been recognized, but there is already evidence for their involvement in many of the pathophysiological mechanisms underlying the disease. In this review, we summarize the current knowledge of the functions and underlying mechanisms of lncRNA activity with a focus on type 2 diabetes mellitus and related renal and retinal complications of the disease. We also discuss the potential of lncRNAs to serve as therapeutic targets for drug development and diagnostic markers for clinical applications in the management of diabetes.

Inhibition of the Cardiac Fibroblast–Enriched lncRNA Meg3 Prevents Cardiac Fibrosis and Diastolic Dysfunction

Rationale:

Cardiac fibroblasts (CFs) drive extracellular matrix remodeling after pressure overload, leading to fibrosis and diastolic dysfunction. Recent studies described the role of long noncoding RNAs (lncRNAs) in cardiac pathologies. Nevertheless, detailed reports on lncRNAs regulating CF biology and describing their implication in cardiac remodeling are still missing.

Objective:

Here, we aimed at characterizing lncRNA expression in murine CFs after chronic pressure overload to identify CF-enriched lncRNAs and investigate their function and contribution to cardiac fibrosis and diastolic dysfunction.

Methods and Results:

Global lncRNA profiling identified several dysregulated transcripts. Among them, the lncRNA maternally expressed gene 3 ( Meg3 ) was found to be mostly expressed by CFs and to undergo transcriptional downregulation during late cardiac remodeling. In vitro, Meg3 regulated the production of matrix metalloproteinase-2 (MMP-2). GapmeR-mediated silencing of Meg3 in CFs resulted in the downregulation of Mmp -2 transcription, which, in turn, was dependent on P53 activity both in the absence and in the presence of transforming growth factor-β I. Chromatin immunoprecipitation showed that further induction of Mmp -2 expression by transforming growth factor-β I was blocked by Meg3 silencing through the inhibition of P53 binding on the Mmp-2 promoter. Consistently, inhibition of Meg3 in vivo after transverse aortic constriction prevented cardiac MMP-2 induction, leading to decreased cardiac fibrosis and improved diastolic performance.

Conclusions:

Collectively, our findings uncover a critical role for Meg3 in the regulation of MMP-2 production by CFs in vitro and in vivo, identifying a new player in the development of cardiac fibrosis and potential new target for the prevention of cardiac remodeling.

Epigenome Aberrations: Emerging Driving Factors of the Clear Cell Renal Cell Carcinoma

Clear cell renal cell carcinoma (ccRCC), the most common form of Kidney cancer, is characterized by frequent mutations of the von Hippel-Lindau (VHL) tumor suppressor gene in ~85% of sporadic cases. Loss of pVHL function affects multiple cellular processes, among which the activation of hypoxia inducible factor (HIF) pathway is the best-known function. Constitutive activation of HIF signaling in turn activates hundreds of genes involved in numerous oncogenic pathways, which contribute to the development or progression of ccRCC. Although VHL mutations are considered as drivers of ccRCC, they are not sufficient to cause the disease. Recent genome-wide sequencing studies of ccRCC have revealed that mutations of genes coding for epigenome modifiers and chromatin remodelers, including PBRM1, SETD2 and BAP1, are the most common somatic genetic abnormalities after VHL mutations in these tumors. Moreover, recent research has shed light on the extent of abnormal epigenome alterations in ccRCC tumors, including aberrant DNA methylation patterns, abnormal histone modifications and deregulated expression of non-coding RNAs. In this review, we discuss the epigenetic modifiers that are commonly mutated in ccRCC, and our growing knowledge of the cellular processes that are impacted by them. Furthermore, we explore new avenues for developing therapeutic approaches based on our knowledge of epigenome aberrations of ccRCC.

Potential applications of MEG3 in cancer diagnosis and prognosis

LncRNAs are emerging as integral functional and regulatory components of normal biological activities and are now considered as critically involved in the development of different diseases including cancer. In this review, we summarized recent findings on maternally expressed gene 3 (MEG3), a noncoding lncRNA, locates in the imprinted DLK1–MEG3 locus on human chromosome 14q32.3 region. MEG3 is expressed in normal tissues but is either lost or decreased in many human tumors and tumor derived cell lines. Studies have demonstrated that MEG3 is associated with cancer initiation, progression, metastasis and chemo-resistance. MEG3 may affect the activities of TP53, MDM2, GDF15, RB1 and some other key cell cycle regulators. In addition, the level of MEG3 showed good correlation with cancer clinicopathological grade. In summary, MEGs is an RNA-based tumor suppressor and is involved in the etiology, progression, and chemosensitivity of cancers. The alteration of MEG3 levels in various cancers suggested the possibility of using MEG3 level for cancer diagnosis and prognosis.

Overexpression of Long Non-Coding RNA MEG3 Inhibits Proliferation of Hepatocellular Carcinoma Huh7 Cells via Negative Modulation of miRNA-664

Evidence is accumulating that long non-coding RNAs (lncRNAs) are involved in human tumorigenesis and dysregulated in many cancers, including hepatocellular carcinoma (HCC). Because lncRNAs can regulate essential pathways that contribute to tumor initiation and progression with their tissue specificity, lncRNAs are valuable biomarkers and therapeutic targets. Maternally expressed gene 3 (MEG3) is a lncRNA overexpressed in HCC cells that inhibits HCC progression, however, the mechanism remains largely unknown. Recently, a novel regulatory mechanism has been proposed in which RNAs can cross-talk with each other via competing for shared microRNAs (miRNAs). The proposed competitive endogenous RNAs could mediate the bioavailability of miRNAs on their targets, thus imposing another level of post-transcriptional regulation. In the current study, we demonstrated that MEG3 is down-regulated in HCC tissues. MEG3 over-expression imposes another level of post-transcriptional regulation, whereas MEG3 overexpression increase the expression of the miR-664 target gene, ADH4, through competitive "sponging" miR-664. In addition, NF-κB may affect transcription of MEG3 by directly binding to the promoter region. Our data revealed that NF-κB may affect the transcript of MEG3. MEG3 overexpression inhibited the proliferation of HCC cells, at least in part by affecting miR-664mediated regulation of ADH4. Together, these results suggest that MEG3 is a suppressor of tumor which acts in part through "sponging" miR-664. J. Cell. Biochem. 118: 3713-3721, 2017. © 2017 Wiley Periodicals, Inc.

DLK1-DIO3 imprinted locus deregulation in development, respiratory disease, and cancer

INTRODUCTION

The imprinted DLK1-DIO3 locus at 14q32.1-32.31 holds biological significance in fetal development, whereby imprinting errors are causal to developmental disorders. Emerging evidence has implicated this locus in other diseases including cancer, highlighting the biological parallels between fetal organ and tumour development. Areas covered: Controlled regulation of gene expression from the imprinted DLK1-DIO3 locus at 14q32.1-32.31 is crucial for proper fetal development. Deregulation of locus gene expression due to imprinting errors has been mechanistically linked to the developmental disorders Kagami-Ogata Syndrome and Temple Syndrome. In adult tissues, deregulation of locus genes has been associated with multiple malignancies although the causal genetic mechanisms remain largely uncharacterised. Here, we summarize the genetic mechanisms underlying the developmental disorders that arise as a result of improper locus imprinting and the resulting developmental phenotypes, emphasizing both the coding and noncoding components of the locus. We further highlight biological parallels common to both fetal development and disease, with a specific focus on lung development, respiratory disease, and lung cancer. Expert commentary: Many commonalities between respiratory and developmental defects have emerged with respect to the 14q32 locus, emphasizing the importance of studying the effects of imprinting on gene regulation patterns at this locus in both biological settings.

MEG3 is a prognostic factor for CRC and promotes chemosensitivity by enhancing oxaliplatin-induced cell apoptosis

A major reason for the failure of advanced colorectal cancer (CRC) treatment is the occurrence of chemoresistance to oxaliplatin-based chemotherapy. Recently, studies have shown that long non-coding RNAs (lncRNAs) play an important role in drug resistance. Using HiSeq sequencing methods, we identified that lncRNAs show differential expression levels in oxaliplatin-resistant (OxR) and non-resistant CRC patients. RT-qPCR was then performed in tissues and serum samples, and lncRNA MEG3 was verified to be downregulated in non-responding patients and to have considerable discriminating potential to identify responding patients from non-responding patients. Moreover, decreased serum MEG3 expression was associated with poor chemoresponse and low survival rate in CRC patients receiving oxaliplatin treatment. Subsequently, OxR cell lines were established, and MEG3 was significantly downregulated in HT29 OxR and SW480 OxR cells. In addition, overexpression of MEG3 with pMEG3 reversed oxaliplatin resistance in both CRC cell lines. Flow cytometric apoptosis analysis indicated that MEG3 promoted CRC cell apoptosis. More importantly, MEG3 enhanced oxaliplatin‑induced cell cytotoxicity in CRC. In conclusion, our integrated approach demonstrated that decreased expression of lncRNA MEG3 in CRC confers potent poor therapeutic efficacy, and that MEG3 promotes chemosensitivity by enhancing oxaliplatin-induced cell apoptosis. Thus, overexpression of MEG3 may be a future direction by which to develop a novel therapeutic strategy to overcome oxaliplatin resistance of CRC patients.

Long Noncoding RNA and Cancer: A New Paradigm

In addition to mutations or aberrant expression in the protein-coding genes, mutations and misregulation of noncoding RNAs, in particular long noncoding RNAs (lncRNA), appear to play major roles in cancer. Genome-wide association studies of tumor samples have identified a large number of lncRNAs associated with various types of cancer. Alterations in lncRNA expression and their mutations promote tumorigenesis and metastasis. LncRNAs may exhibit tumor-suppressive and -promoting (oncogenic) functions. Because of their genome-wide expression patterns in a variety of tissues and their tissue-specific expression characteristics, lncRNAs hold strong promise as novel biomarkers and therapeutic targets for cancer. In this article, we have reviewed the emerging functions and association of lncRNAs in different types of cancer and discussed their potential implications in cancer diagnosis and therapy. Cancer Res; 77(15); 3965-81. ©2017 AACR.

LncRNA as a Therapeutic Target for Angiogenesis

BACKGROUND

Out of 3 billion base pairs in human genome only ~2% code for proteins; and out of 180,000 transcripts in human cells, about 20,000 code for protein, remaining 160,000 are non-coding transcripts. Most of these transcripts are more than 200 base pairs and constitute a group of long non-coding RNA (lncRNA). Many of the lncRNA have its own promoter, and are well conserved in mammals. Accumulating evidence indicates that lncRNAs act as molecular switches in cellular differentiation, movement, apoptosis, and in the reprogramming of cell states by altering gene expression patterns. However, the role of this important group of molecules in angiogenesis is not well understood. Angiogenesis is a complex process and depends on precise regulation of gene expression.

CONCLUSION

Dysregulation of transcription during this process may lead to several diseases including various cancers. As angiogenesis is an important process in cancer pathogenesis and treatment, lncRNA may be playing an important role in angiogenesis. In support of this, lncRNA microvascular invasion in hepatocellular carcinoma (MVIH) has been shown to activate angiogenesis. Furthermore, lncRNA-Meg3-knockout mouse showed increased expression of vascular endothelial growth factor pathway genes and increased cortical microvessel density. Overall, there is strong evidence that lncRNA is an important class of regulatory molecule, and a number of studies have demonstrated that these can be targeted to change cellular physiology and functions. In this review, we have attempted to summarize these studies and elucidate the potential of this novel regulatory molecule as a therapeutic target.

LncRNA MEG3 downregulation mediated by DNMT3b contributes to nickel malignant transformation of human bronchial epithelial cells via modulating PHLPP1 transcription and HIF-1α translation

Long noncoding RNAs (lncRNAs) are emerging as key factors in various fundamental cellular biological processes, and many of them are likely to have functional roles in tumorigenesis. Maternally expressed gene 3 (MEG3) is an imprinted gene located at 14q32 that encodes a lncRNA, and the decreased MEG3 expression has been reported in multiple cancer tissues. However, nothing is known about the alteration and role of MEG3 in environmental carcinogen-induced lung tumorigenesis. Our present study, for the first time to the best of our knowledge, discovered that environmental carcinogen nickel exposure led to MEG3 downregulation, consequently initiating c-Jun-mediated PHLPP1 transcriptional inhibition and hypoxia-inducible factor-1α (HIF-1α) protein translation upregulation, in turn resulting in malignant transformation of human bronchial epithelial cells. Mechanistically, MEG3 downregulation was attributed to nickel-induced promoter hypermethylation via elevating DNMT3b expression, whereas PHLPP1 transcriptional inhibition was due to the decreasing interaction of MEG3 with its inhibitory transcription factor c-Jun. Moreover, HIF-1α protein translation was upregulated via activating the Akt/p70S6K/S6 axis resultant from PHLPP1 inhibition in nickel responses. Collectively, we uncover that nickel exposure results in DNMT3b induction and MEG3 promoter hypermethylation and expression inhibition, further reduces its binding to c-Jun and in turn increasing c-Jun inhibition of PHLPP1 transcription, leading to the Akt/p70S6K/S6 axis activation, and HIF-1α protein translation, as well as malignant transformation of human bronchial epithelial cells. Our studies provide a significant insight into understanding the alteration and role of MEG3 in nickel-induced lung tumorigenesis.

Microarray expression profiling of long non-coding RNAs in epithelial ovarian cancer

Although numerous long non-coding RNAs (lncRNAs) have been identified to be important in human cancer, their potential regulatory roles in epithelial tumorigenesis and tumor progression in ovarian cancer remain unclear. The purpose of the present study was to investigate lncRNAs that were differentially expressed (DE) in epithelial ovarian cancer and to explore their potential functions. The lncRNA profiles in five pairs of human epithelial ovarian cancer tissues and their adjacent normal tissues were described using microarrays. The results of the microarray analysis revealed that 672 upregulated and 549 downregulated (fold-change ≥2.0) lncRNAs were DE between the cancerous and normal tissues. Reverse transcription-quantitative polymerase chain reaction was used to validate the microarray results using four upregulated (RP11-1C1.7, XLOC_003286, growth arrest-specific 5 and ZNF295-AS1) and four downregulated (protein tyrosine kinase 7, maternally expressed gene 3, AC079776.2 and ribosomal protein lateral stalk subunit P0 pseudogene 2) lncRNAs. Furthermore, gene ontology and pathway analyses were used to carry out functional analyses of the candidate genes of DE lncRNAs. The results identified lncRNAs with significantly altered expression profiles in human epithelial ovarian cancer cells compared with those in adjacent normal cells. These data offer new insights into the occurrence and development of epithelial ovarian cancer, and these lncRNAs may provide novel molecular biomarkers for further research on epithelial ovarian cancer.

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.

microRNA-22 can regulate expression of the long non-coding RNA MEG3 in acute myeloid leukemia

Aim

Acute myeloid leukemia (AML) is the most common blood tumor with poor prognosis. At present, the research found that the pathogenesis of AML is related to many factors, such as recurrent somatic mutations and gene expression and epigenetic changes, however, the molecular mechanism of AML is still unclear. Long non-coding RNA MEG3 is a newly found tumor suppressor and plays a very important role in the regulation of a variety of tumor formation and progression. Studies found that the MEG3 expression was significantly decreased in AML. However, to date, it is not clear the cause of its abnormal expression. Therefore, the molecular mechanism of AML is urgently needed to study the molecular mechanism of AML.

Methods

The different expression level of MEG3, TET2, miR-22-3p, miR-22-5p in AML was detected by real-time quantification PCR. MEG3, TET2, miR-22-3p, miR-22-3p expression cell pools in K562 cells was used to interfering and TET2, MEG3 TET2, relations with miR-22-3p, miR-22-5p. The effect of AML cell on proliferation was evaluated by TET2 lower expression.

Results

1. The lower expression of MEG3 and TET2 in AML cell lines was detected by RT-qPCR. 2. The stable MEG3, TET2 overexpression cell pools in K562 cells was successful established. 3. After transfection, MTT assay revealed that cell growth was significantly increased in AML cell lines transfected with TET2 compared with controls.

Conclusions

Our findings suggested that MEG3 is significantly down regulated in AML cell lines.

Epigenetic analysis of bovine parthenogenetic embryonic fibroblasts

Although more than 100 imprinted genes have already been identified in the mouse and human genomes, little is known about genomic imprinting in cattle. For a better understanding of these genes in cattle, parthenogenetically activated bovine blastocysts were transferred to recipient cows to obtain parthenotes, and fibroblasts derived from a Day 40 (Day 0 being the day of parthenogenetic activation) parthenogenetic embryo (BpEFs) were successfully obtained. Bovine embryonic fibroblasts (BEFs) were also isolated from a normal fertilized embryo obtained from an artificially inseminated cow. The expression of imprinted genes was analyzed by RT-PCR. Paternally expressed genes (PEGs) in mouse (viz., IGF2, PEG3, ZAC1, NDN, DLK1, SGCE, and PEG10) were expressed in BEFs, but not in BpEFs, suggesting that these genes are also imprinted in cattle. However, other PEGs in mouse (viz., IMPACT, MAGEL2, SNRPN, and PEG1/MEST) were expressed in both BEFs and BpEFs. These genes may not be imprinted in BEFs. The expression of seven maternally expressed genes in mouse was also analyzed, and only CDKN1C was not expressed in BpEFs. The DNA methylation patterns of repetitive elements (Satellite I, Satellite II, alpha-satellite, and Art2) were not different between the BEFs and BpEFs; however, the differentially methylated region (DMR) of paternally methylated H19 was hypomethylated, whereas those of maternally methylated PEG3 and PEG10 were hypermethylated in BpEFs, as expected. The methylation of the SNRPN DMR was not different between the BEFs and BpEFs, in accordance with the SNRPN expression levels in both cell types. The XIST gene, which is essential for X chromosome inactivation in females, was expressed in BpEFs, whereas its DMR was half-methylated, suggesting that X chromosome inactivation is normal in these cells. Microarray analysis was also applied to identify novel PEGs that should be expressed only in BEFs but not in BpEFs. More than 300 PEG candidate genes, including IGF2, PEG3, and PEG10, were obtained. These results illustrate the epigenetic characteristic of bovine parthenogenetic embryos and contribute to the identification of novel imprinted genes in cattle.

Long non-coding RNA MEG3 induces cell apoptosis in esophageal cancer through endoplasmic reticulum stress

Long non-coding RNAs (lncRNAs) play important roles in diverse biological processes, such as cell growth, apoptosis and migration. Although downregulation of lncRNA MEG3 has been identified in several cancers, little is known about its role in esophageal squamous cell carcinoma (ESCC). The aim of the present study was to detect MEG3 expression in clinical ESCC tissues, investigate its biological functions and the endoplasmic reticulum (ER) stress-relative mechanism. MEG3 expression levels were detected by qRT-PCR in both tumor tissues and adjacent non-tumor tissues from 28 ESCC patients. PcDNA3.1-MEG3 recombinant plasmids were constructed and transfected to EC109 cells. Cell growth was analyzed by CCK-8 assay. Cell apoptosis was analyzed by fluorescence microscope and Annexin V/PI assay. The protein expression was determined by western blot analysis. The results showed that MEG3 decreased significantly in ESCC tissues relative to adjacent normal tissues. PcDNA3.1-MEG3 plasmids were successfully constructed and the expression level of MEG3 significantly increased after MEG3 transfection to EC109 cells. Ectopic expression of MEG3 inhibited EC109 cell proliferation and induced apoptosis in vitro. MEG3 overexpression increased the expression of ER stress‑related proteins (GRP78, IRE1, PERK, ATF6, CHOP and cleaved‑caspase-3). Our results first demonstrate that MEG3 is downregulated in ESCC tissues. MEG3 was able to inhibit cell growth and induced apoptosis in EC109 cells, most probably via activation of the ER stress pathway.

LncRNAs: macromolecules with big roles in neurobiology and neurological diseases

Long noncoding RNAs (lncRNAs) are recently defined as thousands of RNA molecules longer than 200 nucleotides and lacking an appreciable open reading frame in mammals. Although lncRNAs lack protein-coding function, they play critical roles in the regulation of almost all the protein-coding genes in a cell at various stages including chromatin modification, transcription and post-transcriptional processing. It is thus not surprising that lncRNAs may be the crucial regulators in the normal development, physiology and pathology. LncRNAs in neuroscience is a novel research field. Interestingly, recent studies have demonstrated that many lncRNAs are highly expressed in brain and their dysregulations occur in neurological disorders. In this review, we describe the current understanding of lncRNAs in neurobiology and neurological diseases including cerebral injury. LncRNAs could be novel biomarkers and could be potential new targets for new drugs for many neurological diseases in the future, although the related studies are still at in the early stages.

Epigenetics of Huntington's Disease

Huntington's disease (HD) is a genetic, fatal autosomal dominant neurodegenerative disorder typically occurring in midlife with symptoms ranging from chorea, to dementia, to personality disturbances (Philos Trans R Soc Lond Ser B Biol Sci 354:957-961, 1999). HD is inherited in a dominant fashion, and the underlying mutation in all cases is a CAG trinucleotide repeat expansion within exon 1 of the HD gene (Cell 72:971-983, 1993). The expanded CAG repeat, translated into a lengthened glutamine tract at the amino terminus of the huntingtin protein, affects its structural properties and functional activities. The effects are pleiotropic, as huntingtin is broadly expressed in different cellular compartments (i.e., cytosol, nucleus, mitochondria) as well as in all cell types of the body at all developmental stages, such that HD pathogenesis likely starts at conception and is a lifelong process (Front Neurosci 9:509, 2015). The rate-limiting mechanism(s) of neurodegeneration in HD still remains elusive: many different processes are commonly disrupted in HD cell lines and animal models, as well as in HD patient cells (Eur J Neurosci 27:2803-2820, 2008); however, epigenetic-chromatin deregulation, as determined by the analysis of DNA methylation, histone modifications, and noncoding RNAs, has now become a prevailing feature. Thus, the overarching goal of this chapter is to discuss the current status of the literature, reviewing how an aberrant epigenetic landscape can contribute to altered gene expression and neuronal dysfunction in HD.

[Progress of Long Non-coding RNAs in Non-small Cell Lung Cancer]

Lung cancer related death is the most common cause of cancer death worldwide. Non-coding RNA has no protein coding capacity, but can play roles in a variety of biology. Long non-coding RNA (lncRNA) is at least 200 nt long. A variety of lncRNAs could promote or inhibit tumor development and progression in many tumors, including non-small cell lung cancer (NSCLC). Due to their fundamental role in regulating gene expression, they involve in biological mechanism of the tumor, and so they are expected to be new cancer biomarkers. In this review, we emphasized the roles of lncRNAs in NSCLC, and discuss them as diagnostic and prognostic markers and as therapeutic targets.

Hotair facilitates hepatic stellate cells activation and fibrogenesis in the liver

Long non-coding RNAs (lncRNAs) are increasingly recognized as major players in regulating various biological processes. LncRNA HOX transcript antisense RNA (Hotair) has been extensively studied in cancer. However, the role of Hotair in liver fibrosis remains unknown. Here we observed that Hotair expression was significantly increased in CCl₄-induced mouse liver fibrosis models, human fibrotic livers and activated hepatic stellate cells (HSCs) by TGF-β1 stimulation. Enforced expression of Hotair in LX-2 cells promoted cell proliferation and activation while inhibition of its expression had an opposite effect. Furthermore, we found that Hotair may act as an endogenous 'sponge' of miR-148b, which regulates expression of the DNMT1/MEG3/p53 pathways in HSCs. Intriguingly, Hotair enhanced polycomb repressive complex 2 (PRC2) occupancy and histone H3K27me3 repressive marks, specifically at the MEG3 promoter region. Finally, we found that Hotair forms an RNA/DNA hybrid and recruits PRC2 to MEG3 promoter. These data suggest that Hotair inhibition may represent a promising therapeutic option for suppressing liver fibrosis.

Downregulation of long non-coding RNA MEG3 in nasopharyngeal carcinoma

In our previous whole-transcriptome sequencing analysis, downregulation of a long non-coding RNA, maternally expressed gene 3 (MEG3), was identified in NPC samples. This finding suggests the possible role of MEG3 as a tumor suppressor in this distinctive disease. In the present study, two MEG3 variants, AF119863 (MEG3-AF) and BX247998 (MEG3-BX), were found abundantly expressed in a normal nasopharyngeal epithelial cell line, NP69. Significant downregulation of MEG3-AF was further verified in a panel of NPC samples including xenografts and primary biopsies. MEG3 is an imprinted gene located within chromosome 14q32, a common deleted region in NPC. Both DNA copy number loss and aberrant promoter methylation contributed to MEG3 inactivation. Interestingly, MEG3 expression could successfully be rescued by the treatment of a demethylation agent. Besides, ectopic expression of MEG3 in NPC cell lines resulted in considerable repression of in vitro anchorage-independent growth and in vivo tumorigenicity, in addition to significant inhibition in cell proliferation, colony formation, and induction of cell cycle arrest. Finally, we revealed the association between MEG3 activity and the p53 signaling cascade. Our findings characterize MEG3 as a tumor suppressive long non-coding RNA in NPC and encourage the development of precise long non-coding RNA-targeted epigenetic therapy against this malignancy. © 2016 Wiley Periodicals, Inc.

Involvement of endoplasmic reticulum stress and p53 in lncRNA MEG3-induced human hepatoma HepG2 cell apoptosis

Long non-coding RNAs (lncRNAs) play important roles in diverse biological processes. Although downregulation of lncRNA maternally expressed gene 3 (MEG3) has been identified in several types of cancers, little is known concerning its biological role and regulatory mechanism in hepatoma. Our previous studies demonstrated that MEG3 induces apoptosis in a p53-dependent manner. The aim of the present study was to determine whether endoplasmic reticulum (ER) stress is involved in MEG3‑induced apoptosis. Recombinant lentiviral vectors containing MEG3 (Lv‑MEG3) were constructed and transfected into HepG2 cells. A 3‑(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, RT‑PCR, flow cytometry, western blot analysis, immunofluorescence and immunohistochemistry were applied. Transfected HepG2 cells were also transplanted into nude mice, and the tumor growth curves were determined. The results showed that the recombinant lentivirus of MEG3 was transfected successfully into the HepG2 cells and the expression level of MEG3 was significantly increased. Ectopic expression of MEG3 inhibited HepG2 cell proliferation in vitro and in vivo, and also induced apoptosis. Ectopic expression of MEG3 increased ER stress‑related proteins 78‑kDa glucose‑regulated protein (GRP78), inositol‑requiring enzyme 1 (IRE1), RNA‑dependent protein kinase‑like ER kinase (PERK), activating transcription factor 6 (ATF6), C/EBP homologous protein (CHOP), caspase‑3, as well as p53 and NF‑κB expression accompanied by NF‑κB translocation from the cytoplasm to the nucleus. Furthermore, inhibition of NF‑κB with Bay11‑7082 decreased p53 expression in the MEG3‑transfected cells. These results indicate that MEG3 inhibits cell proliferation and induces apoptosis, partially via the activation of the ER stress and p53 pathway, in which NF‑κB signaling is required for p53 activation in ER stress.

Long noncoding RNA ZNFX1-AS1 suppresses growth of hepatocellular carcinoma cells by regulating the methylation of miR-9

Many long noncoding RNAs have been reported to play pivotal roles in cancer biology. Among them, the long noncoding RNA ZNFX1-AS1 has been confirmed to function in breast cancer progression, but the role of ZNFX1-AS1 in hepatocellular carcinoma (HCC) growth and the related molecular mechanisms still remains unknown. In the present study, we first identified the expression of ZNFX1-AS1 in HCC patients' specimens and HCC cell lines through quantitative reverse transcription polymerase chain reaction. Next, the effects of ZNFX1-AS1 on HCC cell growth and apoptosis were analyzed. MTT assay was used to measure the cell numbers, and fluorescence-activated cell sorting analysis was performed to evaluate cell apoptosis. Finally, the relationship between ZNFX1-AS1 and miR-9 in HCC was studied. Our results suggest that ZNFX1-AS1 was markedly downregulated in HCC samples and cell lines. Overexpression of ZNFX1-AS1 inhibited the cell proliferation and colony formation in HCC cell lines and also induced HCC cell apoptosis. Additionally, miR-9 was lowly expressed in HCC tissues and positively correlated with ZNFX1-AS1 expression. Meanwhile, significant upregulation of miR-9 and downregulation of the methylation of miR-9 promoter CpG island were observed when ZNFX1-AS1 was overexpressed. In summary, our results indicate that ZNFX1-AS1 plays a vital role in HCC progression via regulating the methylation of miR-9 and may be a potential tumor suppressor.

Long Noncoding RNAs in Lung Cancer

Despite great progress in research and treatment options, lung cancer remains the leading cause of cancer-related deaths worldwide. Oncogenic driver mutations in protein-encoding genes were defined and allow for personalized therapies based on genetic diagnoses. Nonetheless, diagnosis of lung cancer mostly occurs at late stages, and chronic treatment is followed by a fast onset of chemoresistance. Hence, there is an urgent need for reliable biomarkers and alternative treatment options. With the era of whole genome and transcriptome sequencing technologies, long noncoding RNAs emerged as a novel class of versatile, functional RNA molecules. Although for most of them the mechanism of action remains to be defined, accumulating evidence confirms their involvement in various aspects of lung tumorigenesis. They are functional on the epigenetic, transcriptional, and posttranscriptional level and are regulators of pathophysiological key pathways including cell growth, apoptosis, and metastasis. Long noncoding RNAs are gaining increasing attention as potential biomarkers and a novel class of druggable molecules. It has become clear that we are only beginning to understand the complexity of tumorigenic processes. The clinical integration of long noncoding RNAs in terms of prognostic and predictive biomarker signatures and additional cancer targets could provide a chance to increase the therapeutic benefit. Here, we review the current knowledge about the expression, regulation, biological function, and clinical relevance of long noncoding RNAs in lung cancer.

Current Insights into Long Non-Coding RNAs in Renal Cell Carcinoma

Renal cell carcinoma (RCC) represents a deadly disease with rising mortality despite intensive therapeutic efforts. It comprises several subtypes in terms of distinct histopathological features and different clinical presentations. Long non-coding RNAs (lncRNAs) are non-protein-coding transcripts in the genome which vary in expression levels and length and perform diverse functions. They are involved in the inititation, evolution and progression of primary cancer, as well as in the development and spread of metastases. Recently, several lncRNAs were described in RCC. This review emphasises the rising importance of lncRNAs in RCC. Moreover, it provides an outlook on their therapeutic potential in the future.

Single-cell analysis of long non-coding RNAs in the developing human neocortex

Background

Long non-coding RNAs (lncRNAs) comprise a diverse class of transcripts that can regulate molecular and cellular processes in brain development and disease. LncRNAs exhibit cell type- and tissue-specific expression, but little is known about the expression and function of lncRNAs in the developing human brain. Furthermore, it has been unclear whether lncRNAs are highly expressed in subsets of cells within tissues, despite appearing lowly expressed in bulk populations.

Results

We use strand-specific RNA-seq to deeply profile lncRNAs from polyadenylated and total RNA obtained from human neocortex at different stages of development, and we apply this reference to analyze the transcriptomes of single cells. While lncRNAs are generally detected at low levels in bulk tissues, single-cell transcriptomics of hundreds of neocortex cells reveal that many lncRNAs are abundantly expressed in individual cells and are cell type-specific. Notably, LOC646329 is a lncRNA enriched in single radial glia cells but is detected at low abundance in tissues. CRISPRi knockdown of LOC646329 indicates that this lncRNA regulates cell proliferation.

Conclusion

The discrete and abundant expression of lncRNAs among individual cells has important implications for both their biological function and utility for distinguishing neural cell types.

Electronic supplementary material

The online version of this article (doi:10.1186/s13059-016-0932-1) contains supplementary material, which is available to authorized users.

Novel Insights into the Role of Long Noncoding RNA in Ocular Diseases

Recent advances have suggested that long noncoding RNAs (lncRNAs) are differentially expressed in ocular tissues and play a critical role in the pathogenesis of different types of eye diseases. Here, we summarize the functions and mechanisms of known aberrantly-expressed lncRNAs and present a brief overview of relevant reports about lncRNAs in such ocular diseases as glaucoma, proliferative vitreoretinopathy (PVR), diabeticretinopathy (DR), and ocular tumors. We intend to highlight comprehensive studies that provide detailed data about the mechanisms of lncRNAs, their applications as diagnostic or prognostic biomarkers, and their potential therapeutic targets. Although our understanding of lncRNAs is still in its infancy, these examples may provide helpful insights into the methods by which lncRNAs interfere with ocular diseases.

Long noncoding RNAs in aging and age-related diseases

Aging is the universal, intrinsic, genetically-controlled, evolutionarily-conserved and time-dependent intricate biological process characterised by the cumulative decline in the physiological functions and their coordination in an organism after the attainment of adulthood resulting in the imbalance of neurological, immunological and metabolic functions of the body. Various biological processes and mechanisms along with altered levels of mRNAs and proteins have been reported to be involved in the progression of aging. It is one of the major risk factors in the patho-physiology of various diseases and disorders. Recently, the discovery of pervasive transcription of a vast pool of heterogeneous regulatory noncoding RNAs (ncRNAs), including small ncRNAs (sncRNAs) and long ncRNAs (lncRNAs), in the mammalian genome have provided an alternative way to study and explore the missing links in the aging process, its mechanism(s) and related diseases in a whole new dimension. The involvement of small noncoding RNAs in aging and age-related diseases have been extensively studied and recently reviewed. However, lncRNAs, whose function is far less explored in relation to aging, have emerged as a class of major regulators of genomic functions. Here, we have described some examples of known as well as novel lncRNAs that have been implicated in the progression of the aging process and age-related diseases. This may further stimulate research on noncoding RNAs and the aging process.

Molecular Plasticity of Male and Female Murine Gonadotropes Revealed by mRNA Sequencing

Gonadotropes in the anterior pituitary gland are of particular importance within the hypothalamic-pituitary-gonadal axis because they provide a means of communication and thus a functional link between the brain and the gonads. Recent results indicate that female gonadotropes may be organized in the form of a network that shows plasticity and adapts to the altered endocrine conditions of different physiological states. However, little is known about functional changes on the molecular level within gonadotropes during these different conditions. In this study we capitalize on a binary genetic strategy in order to fluorescently label murine gonadotrope cells. Using this mouse model allows to produce an enriched gonadotrope population using fluorescence activated cell sorting to perform mRNA sequencing. By using this strategy, we analyze and compare the expression profile of murine gonadotropes in different genders and developmental and hormonal stages. We find that gonadotropes taken from juvenile males and females, from cycling females at diestrus and at proestrus, from lactating females, and from adult males each have unique gene expression patterns with approximately 100 to approximately 500 genes expressed only in one particular stage. We also demonstrate extensive gene-expression profile changes with up to approximately 2200 differentially expressed genes when comparing female and male development, juveniles and adults, and cycling females. Differentially expressed genes were significantly enriched in the GnRH signaling, calcium signaling, and MAPK signaling pathways by Kyoto Encyclopedia of Genes and Genomes analysis. Our data provide an unprecedented molecular view of the primary gonadotropes and reveal a high degree of molecular plasticity within the gonadotrope population.

Biochemical Methods To Investigate lncRNA and the Influence of lncRNA:Protein Complexes on Chromatin

Long noncoding RNAs (lncRNAs), defined as nontranslated transcripts greater than 200 nucleotides in length, are often differentially expressed throughout developmental stages, tissue types, and disease states. The identification, visualization, and suppression/overexpression of these sequences have revealed impacts on a wide range of biological processes, including epigenetic regulation. Biochemical investigations on select systems have revealed striking insight into the biological roles of lncRNAs and lncRNA:protein complexes, which in turn prompt even more unanswered questions. To begin, multiple protein- and RNA-centric technologies have been employed to isolate lncRNA:protein and lncRNA:chromatin complexes. LncRNA interactions with the multi-subunit protein complex PRC2, which acts as a transcriptional silencer, represent some of the few cases where the binding affinity, selectivity, and activity of a lncRNA:protein complex have been investigated. At the same time, recent reports of full-length lncRNA secondary structures suggest the formation of complex structures with multiple independent folding domains and pave the way for more detailed structural investigations and predictions of lncRNA three-dimensional structure. This review will provide an overview of the methods and progress made to date as well as highlight new methods that promise to further inform the molecular recognition, specificity, and function of lncRNAs.

The mechanism of adenosine-mediated activation of lncRNA MEG3 and its antitumor effects in human hepatoma cells

Long non-coding RNA MEG3 is suggested to function as a tumor suppressor. However, the activation mechanism of MEG3 is still not well understood and data are not available on its role under adenosine-induced apoptosis. In this study, HepG2 cells were treated with adenosine or 5-Aza‑cdR. Methylation status of MEG3 promoter was detected by methylation specific PCR (MSP) and MEG3 expression was determined by qRT-PCR. PcDNA3.1-MEG3 recombinant plasmid was constructed and transfected to hepatoma HepG2 and Huh7 cells. Cell growth, morphological changes, cell-cycle distribution and apoptosis were analyzed by MTT assay, fluorescence microscopy and flow cytometry. The mRNA and protein expression levels were detected by qRT-PCR and western blot analysis. MEG3 binding proteins were screened by the improved MS2 biotin tagged RNA affinity purification method. The co-expression network of MEG3 was generated by GO analysis and ILF3 was identified as MEG3 binding protein by RNA pulldown and western blot analysis. Both adenosine and 5-Aza-CdR increased MEG3 mRNA expression and the CpG island of MEG3 gene in HepG2 cells was typical hypermethylation. Ectopic expression of MEG3 inhibited hepatoma cell growth in a time-dependent manner, resulted in cell cycle arrest and induced apoptosis. Ectopic expression of MEG3 increased p53, caspase-3 mRNA and protein levels, decreased MDM2 and cyclin D1 mRNA and protein levels, as well as ILF3 protein expression in HepG2 cells. These findings are the first to identify that adenosine increases MEG3 expression by inhibition of DNA methylation and its antitumor effects is involved in MEG3 activation. ILF3 may participate in the anticancer regulation of MEG3 by interacting with MEG3.

Role of long noncoding RNAs in malignant disease (Review)

Long noncoding RNAs (lncRNAs) are endogenous transcribed RNA molecules without protein-coding potential, ranging between 200 and 100,000 nt in length. LncRNAs regulate the expression of specific genes in several ways, including guiding chromatin-remodeling, and affecting splicing, transcription or translation. The mutations and dysregulation of lncRNAs have been found to be important in various human diseases, but particularly in human cancer. Previous studies have demonstrated that changes to lncRNAs are closely associated with tumorigenesis, metastasis, prognosis and diagnosis. The current review aims to present a brief overview of the associated reports of lncRNAs in malignant neoplasms, including breast cancer, prostate cancer and hematological malignancies. LncRNAs may be evaluated as novel markers in disease diagnosis, and as prospective therapeutic targets for the prevention and treatment of human diseases.

Tumor suppression by MEG3 lncRNA in a human pituitary tumor derived cell line

Human clinically non-functioning pituitary adenomas (NFAs) account for approximately 40% of diagnosed pituitary tumors. Epigenetic mutations in tumor suppressive genes play an important role in NFA development. Maternally expressed gene 3 (MEG3) is a long non-coding RNA (lncRNA) and we hypothesized that it is a candidate tumor suppressor whose epigenetic silencing is specifically linked to NFA development. In this study, we introduced MEG3 expression into PDFS cells, derived from a human NFA, using both inducible and constitutively active expression systems. MEG3 expression significantly suppressed xenograft tumor growth in vivo in nude mice. When induced in culture, MEG3 caused cell cycle arrest at the G1 phase. In addition, inactivation of p53 completely abolished tumor suppression by MEG3, indicating that MEG3 tumor suppression is mediated by p53. In conclusion, our data support the hypothesis that MEG3 is a lncRNA tumor suppressor in the pituitary and its inactivation contributes to NFA development.

Long Noncoding RNA MEG3 Interacts with p53 Protein and Regulates Partial p53 Target Genes in Hepatoma Cells

Maternally Expressed Gene 3 (MEG3) encodes a lncRNA which is suggested to function as a tumor suppressor. Previous studies suggested that MEG3 functioned through activation of p53, however, the functional properties of MEG3 remain obscure and their relevance to human diseases is under continuous investigation. Here, we try to illuminate the relationship of MEG3 and p53, and the consequence in hepatoma cells. We find that transfection of expression construct of MEG3 enhances stability and transcriptional activity of p53. Deletion analysis of MEG3 confirms that full length and intact structure of MEG3 are critical for it to activate p53-mediated transactivation. Interestingly, our results demonstrate for the first time that MEG3 can interact with p53 DNA binding domain and various p53 target genes are deregulated after overexpression of MEG3 in hepatoma cells. Furthermore, results of qRT-PCR have shown that MEG3 RNA is lost or reduced in the majority of HCC samples compared with adjacent non-tumorous samples. Ectopic expression of MEG3 in hepatoma cells significantly inhibits proliferation and induces apoptosis. In conclusion, our data demonstrates that MEG3 functions as a tumor suppressor in hepatoma cells through interacting with p53 protein to activate p53-mediated transcriptional activity and influence the expression of partial p53 target genes.

Expression of the long non-coding RNAs MEG3, HOTAIR, and MALAT-1 in non-functioning pituitary adenomas and their relationship to tumor behavior

PURPOSE

It is becoming evident that long non-coding RNAs (lncRNAs) participate in diverse biological processes via distinct mechanisms. Many lncRNAs have altered expression and likely to have functional roles in tumorigenesis. Although loss of maternally-expressed gene 3 (MEG3) expression has been detected in non-functioning pituitary adenomas (NFPAs), there are no published reports regarding the association between MEG3 expression and the invasive ability of NFPAs. Moreover, the roles of Hox transcript antisense intergenic RNA (HOTAIR) and metastasis-associated lung adenocarcinoma transcript 1 (MALAT-1) in NFPAs have not been examined. To investigate the role of MEG3, HOTAIR, and MALAT-1 in NFPA development and invasion.

METHODS

MEG3, HOTAIR, MALAT-1 and proliferating cell nuclear antigen (PCNA) were detected in 52 NFPA samples and seven normal human anterior pituitaries using real-time quantitative reverse transcription polymerase chain reaction.

RESULTS

MEG3 lncRNA levels gradually decreased whereas HOTAIR lncRNA levels gradually increased from normal anterior pituitaries to non-invasive NFPAs to invasive NFPAs. There was a significant association between MEG3 (P < 0.01) and HOTAIR (P < 0.05) expression and the biological behavior of the tumor. Furthermore, PCNA mRNA levels markedly increased in invasive NFPAs compared to non-invasive ones (P < 0.01). In addition, PCNA mRNA negatively correlated with MEG3 lncRNA levels (P < 0.05).

CONCLUSIONS

MEG3 and HOTAIR expression may correlate with NFPA development and invasion.

Paternal uniparental disomy chromosome 14-like syndrome due a maternal de novo 160 kb deletion at the 14q32.2 region not encompassing the IG- and the MEG3-DMRs: Patient report and genotype-phenotype correlation

The human chromosome 14q32 carries a cluster of imprinted genes which include the paternally expressed genes (PEGs) DLK1 and RTL1, as well as the maternally expressed genes (MEGs) MEG3, RTL1as, and MEG8. PEGs and MEGs expression at the 14q32.2-imprinted region are regulated by two differentially methylated regions (DMRs): the IG-DMR and the MEG3-DMR, which are respectively methylated on the paternal and unmethylated on the maternal chromosome 14 in most cells. Genetic and epigenetic abnormalities affecting these imprinted gene clusters result in two different phenotypes currently known as maternal upd(14) syndrome and paternal upd(14) syndrome. However, only few patients carrying a maternal deletion at the 14q32.2-imprinted critical region have been reported so far. Here we report on the first patient with a maternal de novo deletion of 160 kb at the 14q32.2 chromosome that does not involves the IG-DMR or the MEG3-DMR but elicits a full upd(14)pat syndrome's phenotype encompassing the three mentioned MEGs. By the analysis of this unique genotype-phenotype correlation, we further widen the spectrum of the congenital anomalies associated to this rare disorder and we propose that the paternally expressed imprinted RTL1 gene, as well as its maternally expressed RTL1as antisense transcript, may play a prominent causative role.

Identification of lncRNA MEG3 Binding Protein Using MS2-Tagged RNA Affinity Purification and Mass Spectrometry

Long noncoding RNAs (lncRNAs) are nonprotein coding transcripts longer than 200 nucleotides. Recently in mammals, thousands of long noncoding RNAs have been identified and studied as key molecular players in different biological processes with protein complexes. As a long noncoding RNA, maternally expressed gene 3 (MEG3) plays an important role in many cellular processes. However, the mechanism underlying MEG3 regulatory effects remains enigmatic. By using the specific interaction between MS2 coat protein and MS2 RNA hairpin, we developed a method (MS2-tagged RNA affinity purification and mass spectrometry (MTRAP-MS)) to identify proteins that interact with MEG3. Mass spectrometry and gene ontology (GO) analysis showed that MEG3 binding proteins possess nucleotide binding properties and take part in transport, translation, and other biological processes. In addition, interleukin enhancer binding factor 3 (ILF3) and poly(A) binding protein, cytoplasmic 3 (PABPC3) were validated for their interaction with MEG3. These findings indicate that the newly developed method can effectively enrich lncRNA binding proteins and provides a strong basis for studying MEG3 functions.

The Long Noncoding RNA MEG3 Contributes to Cisplatin Resistance of Human Lung Adenocarcinoma

Long noncoding RNAs (lncRNAs) have been identified as oncogenes or tumor suppressors that are involved in tumorigenesis and chemotherapy drug resistance. Maternally expressed gene 3 (MEG3) is an imprinted gene located at 14q32 that encodes an lncRNA, and decreased MEG3 expression plays an important role in multiple cancers. However, its biological role in the development of the chemoresistance phenotype of human lung adenocarcinoma (LAD) is unknown. This study aimed to observe the expression of MEG3 in LAD and to evaluate its biological role and clinical significance in the resistance of LAD cells to cisplatin. MEG3 expression was markedly decreased in cisplatin-resistant A549/DDP cells compared with parental A549 cells as shown by an lncRNA microarray. MEG3 overexpression in A549/DDP cells increased their chemosensitivity to cisplatin both in vitro and in vivo by inhibiting cell proliferation and inducing apoptosis. By contrast, MEG3 knockdown in A549 cells decreased the chemosensitivity. Moreover, MEG3 was decreased in cisplatin-insensitive LAD tissues while p53 protein levels were decreased and Bcl-xl protein levels increased. Furthermore, patients with lower levels of MEG3 expression showed worse responses to cisplatin-based chemotherapy. These findings demonstrate that MEG3 is significantly downregulated in LAD and partially regulates the cisplatin resistance of LAD cells through the control of p53 and Bcl-xl expression. Thus, MEG3 may represent a new marker of poor response to cisplatin and could be a potential therapeutic target for LAD chemotherapy.