Microarray expression profile analysis of long non-coding RNAs in pancreatic ductal adenocarcinoma

Long Noncoding RNAs in Gastrointestinal Cancer: Tumor Suppression Versus Tumor Promotion

Approximately 80% of the human genome harbors biochemical marks of active transcription that its majority transcribes to noncoding RNAs, namely long noncoding RNAs (lncRNAs). LncRNAs are heterogeneous RNA transcripts that regulate critical biological processes such as cell survival and death. They involve in the progression of different cancers by affecting transcriptional and post-transcriptional modifications as well as epigenetic control of numerous tumor suppressors and oncogenes. Recent findings show that aberrant expression of lncRNAs is associated with tumor initiation, progression, invasion, and overall survival of patients with gastrointestinal (GI) cancers. Some lncRNAs play as tumor suppressors in all GI cancers, but others play as tumor promoters. However, some other lncRNAs might function as a tumor suppressor in one GI cancer, but as a tumor promoter in another GI cancer type. This fact highlights possible context dependency of the expression patterns and roles of at least some lncRNAs in GI cancer development and progression. Here, we review the functional relation of lncRNAs involved in the development and progression of GI cancer by focusing on their roles as tumor suppressor and tumor promoter genes.

Identification of long non-coding RNA SCARNA9L as a novel molecular target for colorectal cancer

The aim of the present study was to analyze the microarray data of human colorectal cancer (CRC) tissues and identify novel therapeutic targets for CRC. Microarray analysis from the GSE73360 and GSE84984 datasets was performed to identify novel long non-coding RNAs (lncRNAs) that were differentially expressed in human CRC tissues. Additionally, small interfering RNAs were used to deplete the expression of the indicated lncRNAs in cells. Colony-formation, wound-closure, and transwell assays were performed on CRC cells to assess their proliferation and migration capacities. Through microarray analysis, SCARNA9L, SLMO2-ATP5E and LOC100132062 were identified as differentially expressed lncRNAs in CRC tissues. The present study demonstrated that the ablation of SCARNA9L inhibited cell proliferation and arrested the cell cycle of SW480 and SW620 CRC cells. Additionally, depletion of SCARNA9L restrained the migration of CRC cells in vitro. Overall, the present study investigated the potential involvement of SCARNA9L in CRC and suggests SCARNA9L as a potential biomarker.

The HOTAIRM1/miR-107/TDG axis regulates papillary thyroid cancer cell proliferation and invasion

The long noncoding RNA (lncRNA), HOX antisense intergenic RNA myeloid 1 (HOTAIRM1), has been shown to act as a tumor suppressor in various human cancers. However, the overall biological roles and clinical significance of HOTAIRM1 in papillary thyroid cancer (PTC) have not been investigated. In this study, we used quantitative reverse transcription PCR (qRT-PCR) to show that HOTAIRM1 was significantly downregulated in PTC tissues and low HOTAIRM1 expression levels were associated with lymph node metastasis and advanced TNM stage. We performed Cell Counting Kit-8, plate colony-formation, flow cytometric apoptosis, transwell, and scratch wound healing assays. Overexpression of HOTAIRM1 was found to inhibit PTC cell proliferation, invasion, and migration in vitro. Additionally, we identified miR-107 as a target of HOTAIRM1 using online bioinformatics tools. Dual-luciferase reporter gene and RNA immunoprecipitation assays were used to confirm that HOTAIRM1 acted as a competing endogenous RNA of miR-107. Furthermore, enhancement of miR-107 could potentially reverse the effects of HOTAIRM1 overexpression in vitro. Inhibition of miR-107 suppressed PTC cell proliferation, invasion, and migration in vitro. HOTAIRM1 overexpression and miR-107 inhibition impaired tumorigenesis in vivo in mouse xenografts. Bioinformatics prediction and a dual-luciferase reporter gene assay demonstrated the binding between miR-107 and the 3'-untranslated region of TDG. The results of qRT-PCR and western blotting assays suggested that HOTAIRM1 could regulate the expression of TDG in an miR-107-meditated manner. In conclusion, we validated HOTAIRM1 as a novel tumor-suppressor lncRNA in PTC and proposed that the HOTAIRM1/miR-107/TDG axis may serve as a therapeutic target for PTC.

Long Noncoding RNA HOTAIRM1 Maintains Tumorigenicity of Glioblastoma Stem-Like Cells Through Regulation of HOX Gene Expression

Noncoding RNAs regulate transcription of gene expression and play an important role in the pathogenesis of glioblastomas. These tumors are heterogeneous with some glioma stem cells (GSCs) that are highly tumorigenic subpopulations of cells contributing to recurrence and treatment resistance. In this study, GSCs were established by neurosphere cultures of primary glioblastoma cells and validated by the expression of GSC marker CD133. The expression of the long noncoding RNA HOTAIRM1 was detected using real-time quantitative reverse transcription PCR (qRT-PCR). The role of HOTAIRM1 in the proliferation, apoptosis, stemness, and tumorigenicity of GSCs was investigated by soft agar colony formation, flow cytometry, TUNEL analysis, sphere formation, and in vivo xenograft models through silencing of HOTAIRM1. The expression of HOTAIRM1 and the neighboring HOX genes were analyzed by qRT-PCR in different grades of gliomas and nontumor tissues. We found that HOTAIRM1 is significantly elevated in GSCs. The silencing of HOTAIRM1 significantly impairs the proliferation, apoptosis, self-renewal, tumorigenesis of GSCs. In addition, HOTAIRM1 is significantly upregulated in gliomas and associated with tumor grade and patient survival. HOTAIRM1 neighboring genes, HOXA1, HOXA2, and HOXA3, are also significantly upregulated in gliomas and correlate with the expression of HOTAIRM1. Among them, HOXA2 and HOXA3 were identified as being upregulated in GSCs and contributed to the self-renewal of these stem cells. Taken together, our results demonstrate that HOTAIRM1 plays a critical role in the self-renewal of GSCs. These data also suggest that overexpression of HOTAIRM1 can be a negative prognostic factor for patient survival in malignant glioma and may be a promising potential therapeutic target.

HOTAIRM1 lncRNA is downregulated in clear cell renal cell carcinoma and inhibits the hypoxia pathway

HOXA Transcript Antisense RNA, Myeloid-Specific 1 (HOTAIRM1) is a conserved long non-coding RNA (lncRNA) involved in myeloid and neural differentiation that is deregulated in acute myeloid leukemia and other cancers. Previous studies focused on the nuclear unspliced HOTAIRM1 transcript, however cytoplasmic splice variants exist whose roles have remained unknown. Here, we report novel functions of HOTAIRM1 in the kidney. HOTAIRM1 transcripts are induced during renal lineage differentiation of embryonic stem cells and required for expression of specific renal differentiation genes. We show that the major HOTAIRM1 transcript in differentiated cells is the spliced cytoplasmic HM1-3 isoform and that HM1-3 is downregulated in >90% of clear cell renal cell carcinomas (ccRCCs). Knockdown of HM1-3 in renal cells deregulates hypoxia-responsive and angiogenic genes, including ANGPTL4. Furthermore, HOTAIRM1 transcripts are downregulated by hypoxia-mimetic stress and knockdown of the cytoplasmic HM1-3 isoform in normoxic cells post-transcriptionally induces Hypoxia-Inducible Factor 1α (HIF1α) protein, a key activator of ANGPTL4. Our results demonstrate the pervasive downregulation of the specific HOTAIRM1 cytoplasmic isoform HM1-3 in ccRCC and suggest possible roles of HOTAIRM1 in kidney differentiation and suppression of HIF1-dependent angiogenic pathways.

LncRNA HOTAIRM1/HOXA1 Axis Promotes Cell Proliferation, Migration And Invasion In Endometrial Cancer

Background

Long non-coding RNA (lncRNA) microarray screening previously identified that HOXA transcript antisense RNA myeloid-specific 1 (HOTAIRM1) was significantly upregulated in type I endometrial cancer (EC). The present study aimed to determine the potential role of HOTAIRM1 and its sense transcript HOXA1 in the development and progression of type I EC.

Methods

We detected the expression levels of HOTAIRM1 and HOXA1 in type I EC tissues by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting and analyzed associated clinical data. Gain- or loss-of-function experiments were used to investigate the biological function of HOTAIRM1 and HOXA1 in type I EC, both in vitro and in vivo.

Results

The expression levels of HOTAIRM1 and HOXA1 were significantly upregulated in type I EC tissues. Furthermore, the expression of HOTAIRM1 and HOXA1 were both significantly correlated with International Federation of Gynecology and Obstetrics (FIGO) stage and lymph node metastasis. The expression of HOTAIRM1 was significantly correlated with that of HOXA1. Knockdown of HOTAIRM1 significantly inhibited cell proliferation, migration, invasion and epithelial–mesenchymal transition (EMT) in vitro, while the over-expression of HOTAIRM1 led to the opposite effects. Moreover, we identified that HOTAIRM1 acts as a regulator for the expression of the HOXA1 gene in type I EC cells. As an oncogene, HOXA1 silencing also caused suppressive effects on tumors by inhibiting cell proliferation, migration and invasion. In addition, we also confirmed the role of HOTAIRM1 and HOXA1 in promoting tumor growth in vivo.

Conclusion

Our findings are the first to identify that HOTAIRM1 functions as an oncogene to promote cell proliferation, migration and invasion by regulating HOXA1 in type I EC. Therefore, the HOTAIRM1/HOXA1 axis is a novel potential prognostic biomarker and new potential therapeutic target for type I EC.

High Expression of Long Noncoding RNA HOTAIRM1 is Associated with the Proliferation and Migration in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is an incurable malignancy. Long noncoding RNA (LncRNA) HOTAIRM1 (HOX antisense intergenic RNA myeloid 1) has been shown to play important roles in the progression of several type cancers. However, the exact role of HOTAIRM1 in PDAC development remains largely unknown. This study aims to evaluate the potential function of HOTAIRM1 in the development and progress of PDAC. HOTAIRM1 expression was measured by RT-qPCR in forty seven paired human PDAC tissues and five PDAC cell lines. SW1990 and PANC-1 cells were transfected with siHOTAIRM1 to achieve HOTAIRM1 silence. MTT assay and colony formation assay were used to detect the effect of HOTAIRM1 knockdown on cell proliferation. The impact of HOTAIRM1 silence on cell cycle and apoptosis was assessed by flow cytometry assay. Transwell migration assay was performed to explore the influence of HOTAIRM1 downregulation on the migratory potential of PDAC cells. Western blot assay was applied to determine the expression changes of cell cycle, apoptosis, and migration-related genes before and after downregulating HOTAIRM1. HOTAIRM1 expression was abnormally upregulated in PDAC tissues and cells when compared with the control samples, and was positively associated with the expression of KRAS gene mutation. In vitro functional experiments, HOTAIRM1 expression was significantly downregulated by transfection with siHOTAIRM1 in SW1990 and PANC cell lines. HOTAIRM1 knockdown attenuated cell proliferation by inducing cell cycle arrest at G0/G1 phase, promoted cell apoptosis, and inhibited cell migration in PDAC cells by regulating related-genes expression. In conclusion, HOTAIRM1 plays a critical role in PDAC progression, which may be a novel diagnostic and rational therapeutic target for the treatment of pancreatic ductal adenocarcinoma.

Downregulation of LINC01638 lncRNA inhibits migration and invasion of pancreatic ductal adenocarcinoma cells by reducing TGF‑β signaling

LINC01638 is a long non-coding RNA (lncRNA) with an oncogenic role in breast cancer, while its involvement in other malignancies is unknown. This study was performed to investigate the potential role of LINC01638 in pancreatic ductal adenocarcinoma (PDAC). The expression of LINC01638 was determined via reverse transcription-quantitative polymerase chain reaction analysis, whereas the levels of transforming growth factor-β1 (TGF-β1) in plasma were measured via ELISA. Receiver operating characteristic curve analysis was conducted to determine the diagnostic value of LINC01638. Additionally, the migratory and invasive abilities of cells were evaluated via Transwell migration and invasion assays. In the present study, LINC01638 was significantly upregulated in tumor tissues compared with adjacent healthy tissues in the majority of patients with PDAC. Plasma levels of LINC01638 were significantly higher in patients with PDAC compared with in healthy controls. In effect, upregulation of plasma LINC01638 distinguished patients with PDAC from healthy controls in receiver operating characteristic analysis. Plasma levels of LINC01638 and TGF-β1 were positively correlated in patients with PDAC, but not in healthy controls. LINC01638 overexpression increased TGF-β1 expression, while silencing of LINC01638 using short hairpin RNA (shRNA) led to reduced TGF-β1 expression in a PDAC cell line. LINC01638 overexpression promoted, while shRNA silencing inhibited, migration and invasion of cell of a PDAC cell line. Treatment with exogenous TGF-β1 attenuated the inhibitory effect of LINC01638 shRNA silencing on cancer cell migration and invasion. It is concluded that LINC01638 lncRNA may be involved in the migration and invasion of PDAC cells via regulation of TGF-β1.

Long non-coding RNA, HOTAIRM1, promotes glioma malignancy by forming a ceRNA network

Long non-coding RNAs play critical roles in tumorigenesis and the immune process. In this study, RNA sequencing data for 946 glioma samples from The Cancer Genome Atlas and the Chinese Glioma Genome Atlas databases were analyzed to evaluate the prognostic value and function of homeobox A transcript antisense RNA myeloid-specific (HOTAIRM)1. HOTAIRM1 expression was associated with clinical and molecular features of glioma: patients with high HOTAIRM1 expression were more likely to be classified as malignant cases, and elevated HOTAIRM1 level was associated with shorter survival time in subgroups stratified by clinical and molecular features. A multivariate Cox regression analysis showed that HOTAIRM1 was an independent prognostic factor for patient outcome. In vitro experiments revealed that HOTAIRM1 knockdown suppressed the malignant behavior of glioma and increased tumor sensitivity to temozolomide. The results of an in silico analysis indicated that HOTAIRM1 promotes the malignancy of glioma by acting as a sponge for microRNA (miR)-129-5p and miR-495-3p. HOTAIRM1 overexpression was also associated with immune activation characterized by enhanced T cell-mediated immune and inflammatory responses. These results suggest that HOTAIRM1 is a prognostic biomarker and potential therapeutic target in glioma.

Identification and characterization of the lncRNA signature associated with overall survival in patients with neuroblastoma

Neuroblastoma (NB) is a commonly occurring cancer among infants and young children. Recently, long non-coding RNAs (lncRNAs) have been using as prognostic biomarkers for therapeutics and interventions in various cancers. Considering the poor survival of NB, the lncRNA-based therapeutic strategies must be improved. This work proposes an overall survival time estimator called SVR-NB to identify the lncRNA signature that is associated with the overall survival of patients with NB. SVR-NB is an optimized support vector regression (SVR)-based method that uses an inheritable bi-objective combinatorial genetic algorithm for feature selection. The dataset of 231 NB patients that contains overall survival information and expression profiles of 783 lncRNAs was used to design and evaluate SVR-NB from the database of gene expression omnibus accession GSE62564. SVR-NB identified a signature of 35 lncRNAs and achieved a mean squared correlation coefficient of 0.85 and a mean absolute error of 0.56 year between the actual and estimated overall survival time using 10-fold cross-validation. Further, we ranked and characterized the 35 lncRNAs according to their contribution towards the estimation accuracy. Functional annotations and co-expression gene analysis of LOC440896, LINC00632, and IGF2-AS revealed the association of co-expressed genes in Kyoto Encyclopedia of Genes and Genomes pathways.

Long noncoding RNA HOTAIRM1 inhibits cell progression by regulating miR-17-5p/ PTEN axis in gastric cancer

OBJECTIVES

This study was conducted to identify the significantly altered long noncoding RNAs (lncRNAs), messenger RNA (mRNA) and pathways in gastric cancer (GC).

METHODS

We used microarray analysis to identify differentially expressed lncRNAs and mRNAs, whereas the obviously changed pathways were found by gene set enrichment analysis. The coexpression network of lncRNA and mRNA was constructed by Cytoscape, and their target relationships with miRNAs were predicted by miRcode and TargetScan. qRT-PCR and Western blot were performed to determine the expression levels of mRNAs and proteins in tissues and cell lines. Dual-luciferase reporter assay was applied to achieve the determination of the specific target relationships. Cell viability, migration, and apoptosis were detected by MTT assay, wound healing assay and flow cytometry, respectively. Through the xenograft assay, the gastric tumor was implanted into nude mice to investigate the influence of HOTAIRM1 in vivo.

RESULTS

HOTAIRM1 and phosphatase and tensin homolog (PTEN) were both downregulated in GC, whereas miR-17-5p was upregulated. Moreover, the PI3K/AKT pathway was found activated in GC. HOTAIRM1 targeted miR-17-5p, whereas PTEN was the downstream target gene of miR-17-5p. HOTAIRM1 suppressed proliferation and migration of GC cell line and induced their apoptosis, whereas miR-17-5p played the opposite role on GC cell line. HOTAIRM1 also postponed tumor growth in vivo and inhibited the PI3K/AKT pathway in GC.

CONCLUSIONS

LncRNA HORAIRM1 suppressed the PI3K/AKT pathway in GC and inhibited the progression of GC by serving as a competing endogenous RNA of miR-17-5p, mediating the expression of PTEN.

HOTAIRM1 competed endogenously with miR-148a to regulate DLGAP1 in head and neck tumor cells

This study is aimed to explore the regulatory effect of lncRNA HOTAIR/miR-148a/DLGAP1 axis on head and neck tumor (HNT) cell growth, cell mobility, and invasiveness. HOTAIRM1, miR-148a, and DLGAP1 level in HNT tissues and adjacent normal tissues were measured by qRT-PCR. Cell Counting Kit-8 (CCK-8) and Transwell (migration and invasion) assay were used to survey the influence of HOTAIRM1, miR-148a, and DLGAP1 on Fadu cells. Nude mouse xenograft was utilized to validate the influence of HOTAIRM1 in vivo. Dual-luciferase reporter assay confirms the relationship between HOTAIRM1 and miR-148a, miR-148a, and DLGAP1. The expression level of HOTAIRM1 was downregulated in human HNT tissues and cells. Overexpression of HOTAIRM1 significantly moderated Fadu cells proliferation, apoptosis, migration, and invasion in vitro and impaired the tumorigenesis in vivo. The expression level of miR-148a was upregulated in human HNT tissue compared to the adjacent tissues. We identified that miR-148a was a target of HOTAIRM1 and its expression levels were reduced by HOTAIRM1. Transfection of miR-148a mimics increased proliferation, migration, and invasion of Fadu cells. DLGAP1 was identified as a novel target of miR-148a and its expression level was promoted by either HOTAIRM1 overexpression or miR-148a knockdown. Overexpression of DLGAP1 also facilitated the cell viability and metastasis of Fadu cells. HOTAIRM1 was confirmed as a tumor suppressor via sponging miR-148a and promote the expression of DLGAP1, which could be regarded as an important target for the prevention and treatment of HNT.

A comprehensive genome-wide analysis of the long noncoding RNA expression profile in metastatic lymph nodes of oral mucosal melanoma

BACKGROUND & AIM

Oral mucosal melanoma (OMM) is a kind of malignancy with extremely rare morbidity. It exhibits a poorer biological behavior and clinical outcome compared with cutaneous melanoma. lncRNAs are endogenous cellular RNA transcripts with no protein-coding potential and are associated with oncogenesis through cis- or trans-acting mechanisms. Despite increased evidence that proved lncRNAs have vital roles in tumorigenesis of mucosal melanoma, little is known about their functions in the progress of lymph node dissemination of OMM.

METHOD

Here, we constructed a lncRNA and mRNA microarray using six metastatic lymph nodes and paired-matched non-metastatic lymph nodes. Then, we performed RT-PCR to validate the microarray data both in primary and metastases. We further constructed lncRNA and mRNA co-expressing networks and analyzed the biological functions by Gene Ontology (GO) and pathway analyses for dysregulated lncRNAs and mRNAs. Cis- and trans-regulation analysis were also performed to explore the specific mechanism of lncRNAs in OMM.

RESULT

Our results showed that 570 lncRNAs were upregulated with 292 lncRNAs downregulated in the metastatic OMM tissues. The results of RT-PCR were consistent with our microarray dataset both in primary and metastases. Gene Ontology (GO) and pathway analyses indicated that they play an important role in the melanin biosynthetic process, new growing cell tip and lysosomes in metastatic OMM. In the cis-regulation analysis, we observed metastasis-associated gene, PLEKHA5, the cis gene of lnc-AEBP2-1_1 and lnc-AEBP2-2_1, and microphthalmia-associated transcription factor (MITF), the cis gene of SAMMSON_3, SAMMSON_5 and lnc-MITF-5_1. In the trans-regulation analysis, CTBP2 and SUZ12 regulated lncRNA expression in the core TF-lncRNA-gene network.

CONCLUSION

Our results suggest that lncRNAs may be involved in the metastasis of OMM, and further investigation is needed to focus on the biological functions and the underlining molecular mechanisms exerted by these dysregulated lncRNAs in OMM.

Reciprocal regulation of chromatin state and architecture by HOTAIRM1 contributes to temporal collinear HOXA gene activation

Thousands of long non-coding RNAs (lncRNAs) have been identified in mammals, many of which represent important regulators of gene expression. However, the mechanisms used by lncRNAs to control transcription remain largely uncharacterized. Here, we report on HOTAIRM1, a promising lncRNA biomarker in leukemia and solid tumors. We find that HOTAIRM1 contributes to three-dimensional chromatin organization changes required for the temporal collinear activation of HOXA genes. We show that distinct HOTAIRM1 variants preferentially associate with either UTX/MLL or PRC2 complexes to modulate the levels of activating and silencing marks at the bivalent domain. HOTAIRM1 contributes to physical dissociation of chromatin loops at the cluster proximal end, which delays recruitment of the histone demethylase UTX and transcription of central HOXA genes. Interestingly, we find overall proximal HOXA gene activation without chromatin conformation changes by HOTAIRM1 in a different cell type. Our results reveal a previously unappreciated relationship between chromatin structure, architecture and lncRNA function.

Linc-ing Circulating Long Non-coding RNAs to the Diagnosis and Malignant Prediction of Intraductal Papillary Mucinous Neoplasms of the Pancreas

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease that lacks effective biomarkers for early detection. We hypothesized that circulating long non-coding RNAs (lncRNAs) may act as diagnostic markers of incidentally-detected cystic PDAC precursors known as intraductal papillary mucinous neoplasms (IPMNs) and predictors of their pathology/histological classification. Using NanoString nCounter® technology, we measured the abundance of 28 candidate lncRNAs in pre-operative plasma from a cohort of pathologically-confirmed IPMN cases of various grades of severity and non-diseased controls. Results showed that two lncRNAs (GAS5 and SRA) aided in differentiating IPMNs from controls. An 8-lncRNA signature (including ADARB2-AS1, ANRIL, GLIS3-AS1, LINC00472, MEG3, PANDA, PVT1, and UCA1) had greater accuracy than standard clinical and radiologic features in distinguishing 'aggressive/malignant' IPMNs that warrant surgical removal from 'indolent/benign' IPMNs that can be observed. When the 8-lncRNA signature was combined with plasma miRNA data and quantitative 'radiomic' imaging features, the accuracy of predicting IPMN pathological classification improved. Our findings provide novel information on the ability to detect lncRNAs in plasma from patients with IPMNs and suggest that an lncRNA-based blood test may have utility as a diagnostic adjunct for identifying IPMNs and their pathology, especially when incorporated with biomarkers such as miRNAs, quantitative imaging features, and clinical data.

Microarray Analysis of the Expression Profile of Long Non-Coding RNAs Indicates lncRNA RP11-263F15.1 as a Biomarker for Diagnosis and Prognostic Prediction of Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a devastating malignancy with poor prognostic outcomes. Accumulating evidence has demonstrated that long non-coding RNAs (lncRNAs) play an important role in the development and progression of carcinogenesis. Nevertheless, little is known about the role of lncRNAs in PDAC. The aim of the current study was to find differentially expressed lncRNAs and related mRNAs in human PDAC tissues and adjacent normal tissues by microarray analysis, and investigate the relationship between lncRNA RP11-263F15.1 levels and the clinicaopathological features of PDAC patients. It was found that 4364 lncRNAs and 4862 related mRNAs were significantly dysregulated in PDAC tissues as compared with adjacent normal tissues with a fold change ≥2.0 (P<0.05). GO and pathway analyses showed that the up-regulated gene profiles were related to several pathways associated with carcinogenesis, while the down-regulated gene profiles were closely correlated with nutrient metabolism. RP11-263F15.1 levels were associated with histologic differentiation (P=0.001). Besides, Kaplan-Meier analysis showed that high expression of RP11-263F15.1 was associated with poor outcomes, but multivariate analysis suggested that RP11-263F15.1 was not an independent factor for predicting prognosis of PDAC. In conclusion, these data indicate that differentially expressed lncRNAs and mRNAs were involved in the carcinogenesis of PDAC, and RP11-263F15.1 may prove to be a potential biomarker for the diagnosis and prognostic prediction of PDAC.

Microarray expression profiles of long non-coding RNAs in germinal center-like diffuse large B-cell lymphoma

Long non-coding RNAs (lncRNAs) are continuously transcribed and are involved in various cellular activities. However, their contributions to the occurrence and development of germinal center B-cell (GCB)-like diffuse large B-cell lymphoma (DLBCL) remain largely unknown. We applied microarray technology to profile the expression of lncRNAs in two different GCB-DLBCL cell lines (OCI-ly1 and OCI-ly19) and normal B lymphocytes. We demonstrated that 21,539 lncRNAs were expressed in all of the samples analyzed. This included 1,648 lncRNAs that showed a ≥2-fold upregulation and 2,671 lncRNAs that displayed a ≥2-fold downregulation in tumor cell lines (P<0.05). The expression levels of 8 lncRNAs were validated by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Bioinformatic analyses (Gene Ontology, pathway and network analysis) were performed to predict how the differentially expressed lncRNAs may function in GCB-DLBCL. Results from the pathway analysis suggested that totals of 64 and 62 biological pathways corresponded to upregulated and downregulated transcripts, respectively (P<0.05). Additionally, we constructed a lncRNA-mRNA network for the purpose of identifying specific coding genes which were co-expressed with 5 selected lncRNAs. Conclusively, our results may contribute to a better understanding of GCB-DLBCL pathogenesis.