Differentially expressed protein-coding genes and long noncoding RNA in early-stage lung cancer

Onco-Ontogeny of Squamous Cell Cancer of the First Pharyngeal Arch Derivatives

Head and neck squamous cell carcinoma (H&NSCC) is an anatomic, biological, and genetic complex disease. It involves more than 1000 genes implied in its oncogenesis; for this review, we limit our search and description to the genes implied in the onco-ontogeny of the derivates from the first pharyngeal arch during embryo development. They can be grouped as transcription factors and signaling molecules (that act as growth factors that bind to receptors). Finally, we propose the term embryo-oncogenesis to refer to the activation, reactivation, and use of the genes involved in the embryo's development during the oncogenesis or malignant tumor invasion and metastasis events as part of an onco-ontogenic inverse process.

A Novel Gene Signature based on Immune Cell Infiltration Landscape Predicts Prognosis in Lung Adenocarcinoma Patients

BACKGROUND

The tumor microenvironment (TME) is created by the tumor and dominated by tumor-induced interactions. Long-term survival of lung adenocarcinoma (LUAD) patients is strongly influenced by immune cell infiltration in TME. The current article intends to construct a gene signature from LUAD ICI for predicting patient outcomes.

METHODS

For the initial phase of the study, the TCGA-LUAD dataset was chosen as the training group for dataset selection. We found two datasets named GSE72094 and GSE68465 in the Gene Expression Omnibus (GEO) database for model validation. Unsupervised clustering was performed on the training cohort patients using the ICI profiles. We employed Kaplan-Meier estimators and univariate Cox proportional-hazard models to identify prognostic differentially expressed genes in immune cell infiltration (ICI) clusters. These prognostic genes are then used to develop a LASSO Cox model that generates a prognostic gene signature. Validation was performed using Kaplan-Meier estimation, Cox, and ROC analysis. Our signature and vital immune-relevant signatures were analyzed. Finally, we performed gene set enrichment analysis (GSEA) and immune infiltration analysis on our finding gene signature to further examine the functional mechanisms and immune cellular interactions.

RESULTS

Our study found a sixteen-gene signature (EREG, HPGDS, TSPAN32, ACSM5, SFTPD, SCN7A, CCR2, S100P, KLK12, MS4A1, INHA, HOXB9, CYP4B1, SPOCK1, STAP1, and ACAP1) to be prognostic based on data from the training cohort. This prognostic signature was certified by Kaplan-Meier, Cox proportional-hazards, and ROC curves. 11/15 immune-relevant signatures were related to our signature. The GSEA results indicated our gene signature strongly correlates with immune-related pathways. Based on the immune infiltration analysis findings, it can be deduced that a significant portion of the prognostic significance of the signature can be attributed to resting mast cells.

CONCLUSION

We used bioinformatics to determine a new, robust sixteen-gene signature. We also found that this signature's prognostic ability was closely related to the resting mast cell infiltration of LUAD patients.

LINC00313 promotes the proliferation and inhibits the apoptosis of chondrocytes via regulating miR-525-5p/GDF5 axis

BACKGROUND

The present study aimed to explore the potentials of lncRNA LINC00313 in osteoarthritis (OA).

METHODS

qRT-PCR was performed to detect the expression of LINC00313 in OA tissues and cells. CCK-8 and EDU were used to detect cell proliferation. The ELISA test kit was conducted to detect the expression of inflammatory factors. Flow cytometry was used to detect the apoptosis rates. Western blot was applied to measure the protein expression. The luciferase reporter gene test was carried out to verify the relationship between miR-525-5p and LINC00313 or GDF5.

RESULTS

The data showed that the expression of LINC00313 was significantly down-regulated in OA tissues and cells. Functionally, LINC00313 promoted the proliferation of chondrocytes and suppressed the secretion of inflammatory factors and cell apoptosis. Moreover, LINC00313 functioned as a ceRNA to up-regulate the expression of GDF5 via sponging miR-525-5p. Luciferase and RNA pull-down assays further verified the interaction between miR-525-5p and LINC00313 (or GDF5). Moreover, overexpression of miR-525-5p or down-regulated GDF5 degraded the cellular functions of chondrocyte. Rescue experiments showed that the overexpression of miR-525-5p reversed the increase in cell viability and the decrease in pro-inflammatory factors and apoptosis rate mediated by LINC00313. The knockdown of GDF5 reversed the promotion of miR-525-5p knockdown on cell viability and the inhibition of pro-inflammatory factors and apoptosis rate.

CONCLUSIONS

LINC00313 inhibited the development of OA through regulating miR-525-5p/GDF5 axis. LncRNA LINC00313 can be used as a potential target for the treatment of OA.

Chronic Inhalation Exposure to Antimony Trioxide Exacerbates the MAPK Signaling in Alveolar Bronchiolar Carcinomas in B6C3F1/N Mice

Antimony trioxide (AT) is used as a flame retardant in fabrics and plastics. Occupational exposure in miners and smelters is mainly through inhalation and dermal contact. Chronic inhalation exposure to AT particulates in B6C3F1/N mice and Wistar Han rats resulted in increased incidences and tumor multiplicities of alveolar/bronchiolar carcinomas (ABCs). In this study, we demonstrated Kras (43%) and Egfr (46%) hotspot mutations in mouse lung tumors (n = 80) and only Egfr (50%) mutations in rat lung tumors (n = 26). Interestingly, there were no differences in the incidences of these mutations in ABCs from rats and mice at exposure concentrations that did and did not exceed the pulmonary overload threshold. There was increased expression of p44/42 mitogen-activated protein kinase (MAPK) (Erk1/2) protein in ABCs harboring mutations in Kras and/or Egfr, confirming the activation of MAPK signaling. Transcriptomic analysis indicated significant alterations in MAPK signaling such as ephrin receptor signaling and signaling by Rho-family GTPases in AT-exposed ABCs. In addition, there was significant overlap between transcriptomic data from mouse ABCs due to AT exposure and human pulmonary adenocarcinoma data. Collectively, these data suggest chronic AT exposure exacerbates MAPK signaling in ABCs and, thus, may be translationally relevant to human lung cancers.

Identification of Differentially Expressed Long Noncoding RNAs as Functional Biomarkers and Construction of Function Enrichment Network in Oral Squamous Cell Carcinoma

Objective

This study aims to find the novel lncRNAs closely related to the progression of oral squamous cell carcinoma (OSCC) by comprehensively analyzing microarray.

Methods

Chip dataset GSE84805 was downloaded from the Gene Expression Omnibus (GEO) database, lncRNA expression profiles of OSCC and paracancerous tissue were obtained, probes sequences reannotation was conducted, and differentially expressed lncRNAs (DELs) and differentially expressed genes (DEGs) were identified. Finally, these data were analyzed by constructing the lncRNA-function enrichment network.

Results

We found that 465 lncRNAs are differentially expressed consisting of 193 upregulated lncRNAs and 272 downregulated lncRNAs. Meanwhile, 811 DEGs were identified with 498 upregulated genes and 313 downregulated genes. Analysis of the lncRNA-function enrichment network showed that these aberrant lncRNAs may be related to focal adhesion, inflammatory response pathway, cell cycle, matrix metalloproteinases, and other biological functions. Also, we found that some key lncRNAs such as LINC00152 and HOXA11-AS have been shown to play an important role in tumor proliferation and migration.

Conclusion

The key lncRNAs may serve as potential molecular markers or therapeutic targets in OSCC formation and development. It can also help us to understand the molecular mechanism of occurrence and development in OSCC.

LINC00313 regulates the metastasis of testicular germ cell tumors through epithelial-mesenchyme transition and immune pathways

Testicular germ cell tumor (TGCT) is a relatively rare entity tumor, accounting for only 1% of all male cancers. However, it is the most common solid tumor in young men between 15 and 34 years old. Long noncoding RNAs (lncRNAs) are involved in various physiological and pathological processes. However, the functions of lncRNAs in TGCT have only rarely been investigated. LncRNAs associated with TGCT were identified using Gene Expression Omnibus (GEO) database and UCSC XENA database data mining. The effects of LINC00313 on NCCIT cell migration and invasion were evaluated in transwell assays. The expression levels of epithelial-mesenchyme transition (EMT)-related proteins in cells knockdown of LINC00313 were analyzed by Western blot. Correlation analyses between lncRNA LINC00313 expression and copy number variation (CNV) and immune cell infiltration were carried out using The Cancer Genome Atl as (TCGA) data. The effect of Panobinostatin targeting LINC00313 in TGCT cells was investigated. We observed higher LINC00313 expression in TGCT. The migratory and invasive properties of TGCT cells were augmented by LINC00313, likely via its effects on modulating the expression of epithelial-mesenchyme transition (EMT) related proteins: CTNNB1, ZEB1, CDH2, Snail and VIM. Moreover, LINC00313 expression and CNV correlated negatively with the infiltration of immune cells. In addition, Panobinostat might be a possible candidate drug to target LINC00313 in TGCT. LINC00313 performs important pro-migration and invasion functions in the pathogenesis of TGCT. LINC00313 could be used as diagnostic, prognostic, immune marker and therapeutic target to develop effective treatment of TGCT.

Integrated computational analysis reveals HOX genes cluster as oncogenic drivers in head and neck squamous cell carcinoma

Alterations in homeobox (HOX) gene expression are involved in the progression of several cancer types including head and neck squamous cell carcinoma (HNSCC). However, regulation of the entire HOX cluster in the pathophysiology of HNSCC is still elusive. By using different comprehensive databases, we have identified the significance of differentially expressed HOX genes (DEHGs) in stage stratification and HPV status in the cancer genome atlas (TCGA)-HNSCC datasets. The genetic and epigenetic alterations, druggable genes, their associated functional pathways and their possible association with cancer hallmarks were identified. We have performed extensive analysis to identify the target genes of DEHGs driving HNSCC. The differentially expressed HOX cluster-embedded microRNAs (DEHMs) in HNSCC and their association with HOX-target genes were evaluated to construct a regulatory network of the HOX cluster in HNSCC. Our analysis identified sixteen DEHGs in HNSCC and determined their importance in stage stratification and HPV infection. We found a total of 55 HNSCC driver genes that were identified as targets of DEHGs. The involvement of DEHGs and their targets in cancer-associated signaling mechanisms have confirmed their role in pathophysiology. Further, we found that their oncogenic nature could be targeted by using the novel and approved anti-neoplastic drugs in HNSCC. Construction of the regulatory network depicted the interaction between DEHGs, DEHMs and their targets genes in HNSCC. Hence, aberrantly expressed HOX cluster genes function in a coordinated manner to drive HNSCC. It could provide a broad perspective to carry out the experimental investigation, to understand the underlying oncogenic mechanism and allow the discovery of new clinical biomarkers for HNSCC.

LncRNAs and the Angiogenic Switch in Cancer: Clinical Significance and Therapeutic Opportunities

Angiogenesis is one of the hallmarks of cancer, and the establishment of new blood vessels is vital to allow for a tumour to grow beyond 1-2 mm in size. The angiogenic switch is the term given to the point where the number or activity of the pro-angiogenic factors exceeds that of the anti-angiogenic factors, resulting in the angiogenic process proceeding, giving rise to new blood vessels accompanied by increased tumour growth, metastasis, and potential drug resistance. Long noncoding ribonucleic acids (lncRNAs) have been found to play a role in the angiogenic switch by regulating gene expression, transcription, translation, and post translation modification. In this regard they play both anti-angiogenic and pro-angiogenic roles. The expression levels of the pro-angiogenic lncRNAs have been found to correlate with patient survival. These lncRNAs are also potential drug targets for the development of therapies that will inhibit or modify tumour angiogenesis. Here we review the roles of lncRNAs in regulating the angiogenic switch. We cover specific examples of both pro and anti-angiogenic lncRNAs and discuss their potential use as both prognostic biomarkers and targets for the development of future therapies.

PP7080 expedites the proliferation and migration of lung adenocarcinoma cells via sponging miR-670-3p and regulating UHRF1BP1

BACKGROUND

An increasing body of evidence has revealed that long non-coding RNAs play a significant part in a variety of human cancers, including lung adenocarcinoma (LUAD).

METHODS

The expression of PP7080, miR-670-3p and UHRF1BP1 in LUAD cells and tissues was detected using a quantitative real-time polymerase chain reaction. The role of PP7080 in LUAD cells was validated by CCK-8, flow cytometry, colony formation, transwell and wound healing assays. The binding capacity between PP7080/UHRF1BP1 and miR-670-3p was confirmed by luciferase reporter assays. Moreover, the interactional mechanism among PP7080, miR-670-3p and UHRF1BP1 was determined by means of RNA immunoprecipitation and western blot assays.

RESULTS

The expression level of PP7080 is up-regulated in LUAD cells and tissues compared to their matched controls. Down-regulation of PP7080 restrained the proliferative and migratory abilities of LUAD cells, but induced cell apoptosis. PP7080 up-regulation led to the opposite results. Moreover, the binding ability between miR-670-3p and PP7080/UHRF1BP1 in LUAD cells was confirmed. A rescue assay revealed that PP7080 contributes to LUAD development by modulating the miR-670-3p/UHRF1BP1 signaling pathway.

CONCLUSIONS

PP7080 expedites the proliferation and migration of LUAD cell via sponging miR-670-3p and modulating UHRF1BP1.

Determination of the key ccRCC-related molecules from monolayer network to three-layer network

Clear cell renal cell carcinoma (ccRCC), with an increasing incidence rate, is one of the ubiquitous cancers. Its pathogenic factors are complicated and the molecular mechanism is not clear. It is essential to analyze the potential key genes related to ccRCC carcinogenesis. In this study, the differentially expressed mRNAs, miRNAs and lncRNAs (DEmRNAs, DEmiRNAs and DElncRNAs) of ccRCC were screened from TCGA database. Then the miRNA-mRNA network, lncRNA-miRNA network and lncRNA-mRNA network were constructed by online database or WGCNA algorithm. Topology attributes of these monolayer networks showed that hsa-mir-155, hsa-mir-200c, hsa-mir-122, hsa-mir-506, hsa-mir-216b, hsa-mir-141, lncRNA AC137723.1 and AC021074.3 are the crucial genes related with the regulatory effects on the proliferation, metastasis and invasion of ccRCC cells. Subsequently, these three monolayer networks were integrated into a lncRNA-miRNA-mRNA multilayer network. Considering node degree, closeness centrality and betweenness centrality, we found hsa-mir-122 is screened out as the only crucial gene in three-layer network. In order to better illustrate the effect of hsa-mir-122 on ccRCC, the lncRNA-hsa-mir-122-mRNA network was constructed with hsa-mir-122 as the center. Pathway analysis of the unique target gene GALNT3 linked to hsa-mir-122 showed that GALNT3 influenced the metabolic process of mucin type O-Glycan biosynthesis. LncRNA AC090377.1 is the unique gene that has target genes among lncRNAs with clinical significance that linked to hsa-mir-122 in the lncRNA-hsa-mir-122-mRNA network. Pathway analysis of AC090377.1 suggested that GUCY2F enriched in phototransduction pathway associated with retina. From monolayer network to three-layer network, hsa-mir-122 is identified as an important molecule in the oncogenesis and progression of ccRCC, offering new strategies to further study of the carcinogenic mechanism of ccRCC.

Isothermal detection of lncRNA using T7 RNA polymerase mediated amplification coupled with fluorescence-based sensor

In this study, the isothermal detection of a cervical cancer-associated long non-coding RNA (lncRNA), namely, lncRNA-ATB, was performed for the first time with high selectivity and sensitivity via a T7 RNA polymerase transcription-mediated amplification system combined with a graphene oxide (GO) fluorescence-based sensor. Specific lncRNA primers with the T7 promoter overhang were designed and further had with the efficient amplification ability of T7 RNA polymerase. This detection platform distinguished the target lncRNA-ATB from other lncRNAs. In addition, the super fluorescence quenching ability of GO resulted in the development of a switch on/off fluorescence sensor. The resulting platform was able to detect target lncRNAs from samples of cervical cancer cell lines (HeLa) and human sera with high selectivity and a low detection limit of 1.96 pg. Therefore, the assay developed in this study demonstrated a high potential as an alternative tool for lncRNA quantification in clinical diagnosis.

LncRNA LINC00313 Knockdown Inhibits Tumorigenesis and Metastasis in Human Osteosarcoma by Upregulating FOSL2 through Sponging miR-342-3p

PURPOSE

Osteosarcoma (OS) is the most common primary bone tumor, with high morbidity in infants and adolescents. Long noncoding RNA LINC00313 has been found to modulate papillary thyroid cancer tumorigenesis and to be dysregulate in lung cancer. However, the role of LINC00313 in OS has not yet been addressed.

MATERIALS AND METHODS

We evaluated mRNA and protein expression using real-time quantitative PCR and Western blotting. Cell proliferation was evaluated using MTT; apoptosis and autophagy were assessed with flow cytometry, Western blotting, and/or GFP-LC3 assay. Transwell assay was conducted to measure cell migration and invasion. Potential target sites for LINC00313 and miR-342-3p were predicted with starBase v.2.0 and TargetScan Human, and verified using luciferase reporter assay, RNA immunoprecipitation, and RNA pull-down assay. In vivo, xenogeneic tumors were induced with U2OS and MG-63 cells, separately.

RESULTS

LINC00313 was upregulated and miR-342-3p was downregulated in OS tissues and cells. High expression of LINC00313 was associated with shorter overall survival. FOSL2 downregulation and miR-342-3p overexpression suppressed cell proliferation and migratory and invasive abilities while promoting apoptosis and autophagy, all of which were consistent with the effects of LINC00313 knockdown. miR-342-3p, sponged by LINC00313, inversely modulated FOSL2 by targeting MG-63 cells, and FOSL2 expression was positively controlled by LINC00313. LINC00313 knockdown suppressed tumor growth in vivo.

CONCLUSION

LINC00313 is upregulated in OS, and LINC00313 knockdown plays a vital anti-tumor role in OS cell progression through a miR-342-3p/FOSL2 axis. Our study suggests that LINC00313 may be a novel, promising biomarker for diagnosis and prognosis of OS.

Sputum long non-coding RNA biomarkers for diagnosis of lung cancer

BACKGROUND

Analysis of molecular changes in sputum may help diagnose lung cancer. Long non-coding RNAs (lncRNAs) play vital roles in various biological processes, and their dysregulations contribute to the development and progression of lung tumorigenesis. Herein, we determine whether aberrant lncRNAs could be used as potential sputum biomarkers for lung cancer.

METHODS

Using reverse transcription PCR, we measure expressions of lung cancer-associated lncRNAs in sputum of a discovery cohort of 67 lung cancer patients and 65 cancer-free smokers with benign diseases and a validation cohort of 59 lung cancer patients and 60 cancer-free smokers with benign diseases.

RESULTS

In the discovery cohort, four of the lncRNAs displayed a significantly different level in sputum of lung cancer patients vs.cancer-free smokers with benign diseases (all P< 0.001). From the four lncRNAs, three lncRNAs (SNHG1, H19, and HOTAIR) are identified as a biomarker panel, producing 82.09% sensitivity and 89.23% specificity for diagnosis of lung cancer. Furthermore, the biomarker panel has a higher sensitivity (82.09% vs. 52.24%, P= 0.02) and a similar specificity compared with sputum cytology (89.23% vs. 90.77%, P= 0.45). In addition, the lncRNA biomarker panel had a higher sensitivity (87.50% vs. 70.07%, p= 0.03) for diagnosis of squamous cell carcinoma compared with adenocarcinoma of the lung, while maintaining the same specificity (89.23%). The potential of the sputum lncRNA biomarkers for lung cancer detection is confirmed in the validation cohort.

CONCLUSION

We have for the first time shown that the analysis of lncRNAs in sputum might be a noninvasive approach for diagnosis of lung cancer.

Circ-SOX4 drives the tumorigenesis and development of lung adenocarcinoma via sponging miR-1270 and modulating PLAGL2 to activate WNT signaling pathway

Background

Lung adenocarcinoma (LUAD), a widespread histopathological subtype of lung cancer, is deemed as a malignant tumor with a peak risk of mortality. Emerged as RNA with a loop structure that depleted protein coding ability, circular RNA (circRNA) has been identified as a regulator in cancer progression. Circ-SOX4, identified as a novel circRNA, has not been studied in any cancer yet. Thus, the regulatory function that circ-SOX4 exerts on LUAD development remains obscure.

Aim of the study

This study aimed to investigate the biological function and molecular mechanism of circ-SOX4 in LUAD.

Methods

The expression of circ-SOX4 was detected by qRT-PCR. CCK-8, colony formation, transwell and wound healing assays were performed to explore the biological function of circ-SOX4 in LUAD. The interaction between miR-1270 and circ-SOX41 (or PLAGL2) was confirmed by RNA pull down, luciferase reporter and RIP assays.

Results

Circ-SOX4 was found to be obviously upregulated in LUAD tissues and cells, and knockdown of it inhibited cell proliferation, invasion and migration in LUAD. Furthermore, silenced circ-SOX4 also inhibited LUAD tumor growth. Molecular mechanism assays revealed that circ-SOX4 interacted with miR-1270 in LUAD. Besides, PLAGL2 was confirmed as a downstream gene of miR-1270. Rescue assays validated that miR-1270 suppression or PLAGL2 overexpression countervailed circ-SOX4 depletion-mediated inhibition on cell proliferation, invasion and migration in LUAD. Additionally, it was discovered that circ-SOX4/miR-1270/PLAGL2 axis activated WNT signaling pathway in LUAD.

Conclusions

Circ-SOX4 boosted the development of LUAD and activate WNT signaling pathway through sponging miR-1270 and modulating PLAGL2, which provided a valuable theoretical basis for exploring underlying therapeutic target in LUAD.

Downregulated long noncoding RNA LINC00313 inhibits the epithelial-mesenchymal transition, invasion, and migration of thyroid cancer cells through inhibiting the methylation of ALX4

Thyroid cancer represents one of the prevalent endocrine cancer with relatively high incidence rate around the world, accompanied by unchanged fatality rate. We probe into the specific role of LINC00313 in mediation of cellular processes of thyroid cancer including proliferation, migration, and invasion through the methylation of aristaless-like homeobox 4 (ALX4). Thyroid cancer-related long noncoding RNAs (lncRNAs) and genes were analyzed by microarray-based analysis. The antitumor effect of LINC00313 was examined with the gain- and loss-of-function experiments. In addition, the binding of LINC00313 and the promoter region of ALX4, and the interaction of LINC00313 with methylation-related proteins were detected. Later, xenograft tumors in nude mice were induced expecting to dig out the modulatory function of LINC00313 in tumor growth of thyroid carcinoma. The microarray-based analysis manifested that LINC00313 was overexpressed, whereas ALX4 was downregulated in thyroid cancer, the results of which were also verified in thyroid cancer tissues. Besides, our results demonstrated that LINC00313 bound to the ALX4 promoter region, and LINC00313 recruited DNMT1 and DNMT3B proteins to promote the methylation of ALX4 promoter region, thus suppressing the ALX4 expression. Finally, the downregulation of LINC00313 and upregulation of ALX4 repressed the AKT/mTOR signaling axis, thus inhibiting proliferative, migratory, invasive abilities as well as epithelial-to-mesenchymal transition (EMT) of thyroid cancer cells. Collectively, downregulated LINC00313 suppresses cell proliferation, migration, as well as invasion of thyroid cancer by inhibiting the methylation of ALX4 and increasing its expression by inactivation of the AKT/mTOR signaling pathway.

UPF1 regulates the malignant biological behaviors of glioblastoma cells via enhancing the stability of Linc-00313

There is growing evidence that the long non-coding RNAs(lncRNAs) play an important role in the biological behaviors of glioblastoma cells. In this study, we elucidated the function and possible effect and molecular mechanisms of lncRNA-Linc-00313 on the biological behaviors of glioblastoma cells as well as UPF1 function as a RNA-binding protein to enhance its stability. Here, we used qRT-PCR and western blot to measure the expression, cell Transfection to disrupt the expression of genes, cell viability analysis, quantization of apoptosis, cell migration, and invasion assays, Reporter vectors construction and luciferase assays to investigate the malignant biological behaviors of cells, human lncRNA microarrays, RNA-Immunoprecipitation, dual-luciferase gene reporter assay, half-life assay and chromatin immunoprecipitation to verify the binding sites, tumor xenograft implantation for in vivo experiment, SPSS 18.0 statistical software for data statistics. UPF1 and Linc-00313 were both upregulated in glioma tissues and cells. Knockdown of UPF1 or Linc-00313 significantly inhibited malignant biological behaviors of glioma cells by regulating miR-342-3p and miR-485-5p, which are downregulated and functioned as tumor suppressors in glioma. Furthermore, Linc-00313 could acted as a competing endogenous RNA(ceRNA) to regulate the expression of Zic4 by binding to miR-342-3p and miR-485-5p. Interestingly, Zic4 could bind to the promoters of UPF1 and Linc-00313 respectively and upregulate the expression of them. These results indicated that a positive-feedback loop was formed in the regulation of the biological behaviors of glioma cells. The study is the first to prove that the UPF1-Linc-00313-miR-342-3p/miR-485-5p-Zic4-SHCBP1 pathway forms a positive-feedback loop and regulates the biological behaviors of U87 and U251 cells, which might provide a new therapeutic target for glioma.

ceRNA network construction and comparison of gastric cancer with or without Helicobacter pylori infection

Gastric cancer (GC) is a lethal disease, and among its variety of etiological factors, Helicobacter pylori (H. pylori) infection is the strongest risk factor. However, the genetic and molecular mechanisms underlying H. pylori-related GC need further elucidation. We investigated the competing endogenous RNA (ceRNA) network differences between H. pylori (+) and H. pylori (-) GC. The long noncoding RNA (lncRNA), microRNA (miRNA), and messenger RNA (mRNA) expression data from 32 adjacent noncancerous samples and 18 H. pylori (+) and 141 H. pylori (-) stomach adenocarcinoma samples were downloaded from the TCGA database. After construction of lncRNA-miRNA-mRNA ceRNA networks of H. pylori (+) and H. pylori (-) GC, Panther and Kobas databases were used to analyze the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Finally, survival analysis was used to discover the key genes. In H. pylori (+) GC, we identified a total of 1,419 lncRNAs, 82 miRNAs, and 2,501 mRNAs with differentially expressed profiles. In H. pylori (-) GC, 2,225 lncRNAs, 130 miRNAs, and 3,146 mRNAs were differentially expressed. Furthermore, three unique pathways (cytokine-cytokine receptor interaction, HIF-1 signaling pathway, and Wnt signaling pathway) were enriched in H. pylori (+) GC. According to the overall survival analysis, three lncRNAs (AP002478.1, LINC00111, and LINC00313) and two mRNAs (MYB and COL1A1) functioned as prognostic biomarkers for patients with H. pylori (+) GC. In conclusion, our study has identified the differences in ceRNA regulatory networks between H. pylori (+) and H. pylori (-) GC and provides a rich candidate reservoir for future studies.

Long noncoding RNAs in autoimmune diseases

With the completion of the human genome project and further development of high-throughput genomic technologies, interest in long noncoding RNAs (lncRNAs), which are defined as non-protein-coding RNAs at least 200 nucleotides in length, has strongly increased, and lncRNAs have become a major research direction. Increasing evidence demonstrates that lncRNAs are closely related to human growth and development and to disease occurrence via various mechanisms. lncRNAs also play crucial roles in the differentiation and activation of immune cells, and their relationships with human autoimmune diseases have received increasing attention. The development of biotechnology has led to the gradual discovery of many potential lncRNA functions. In this review, we discuss various lncRNAs that have been implicated in different human autoimmune diseases, focusing on their clinical applications as potential biomarkers and therapeutic targets in the pathologies of diverse human autoimmune diseases. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 468-475, 2019.

Comprehensive analysis of long noncoding RNA-associated competing endogenous RNA network in cholangiocarcinoma

BACKGROUND

Long non-coding RNAs (lncRNAs) can interact with microRNAs (miRNAs) as a competing endogenous RNA (ceRNA) to regulate the expression of target genes, which can largely influence on tumorigenesis and tumor progression. However, the role of lncRNA-mediated ceRNAs in cholangiocarcinoma (CCA) remains unknown. This study aimed to develop novel lncRNAs as well as their action mechanisms in CCA.

METHODS

The expression profiles of lncRNAs, miRNAs, and mRNAs of 36 CCA tissues and 9 non-tumor bile duct tissues were obtained from The Cancer Genome Atlas (TCGA) database. The differentially expressed RNAs werre identified using the DESeq package in R. The ceRNA network was constructed in CCA based on bioinformatics generated from miRcode, miRTarBase, miRDB, and TargetScan. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed using "DAVID 6.8" and R packages "Clusterprofile". Survival analysis was performed based on Kaplan-Meier curve analysis.

RESULTS

We identified a total of 1411 differentially expressed lncRNAs, 3494 mRNAs, and 64 miRNAs between CCA and matched normal tissues. By combining the data predicted by databases with intersection RNAs, a lncRNA-miRNA-mRNA ceRNA network consisting of 116 lncRNAs, 14 miRNAs and 59 mRNAs was established. According to the survival analysis, we detected 11 DElncRNA to have a significant impact on the overall survival in patients with CCA (P < 0.05).

CONCLUSIONS

Our study identified novel lncRNAs associated with CCA progression and prognosis and provided data to further understand lncRNA-mediated ceRNA regulatory mechanisms in the pathogenesis of CCA.

A Plasma Long Noncoding RNA Signature for Early Detection of Lung Cancer

The early detection of lung cancer is a major clinical challenge. Long noncoding RNAs (lncRNAs) have important functions in tumorigenesis. Plasma lncRNAs directly released from primary tumors or the circulating cancer cells might provide cell-free cancer biomarkers. The objective of this study was to investigate whether the lncRNAs could be used as plasma biomarkers for early-stage lung cancer. By using droplet digital polymerase chain reaction, we determined the diagnostic performance of 26 lung cancer–associated lncRNAs in plasma of a development cohort of 63 lung cancer patients and 33 cancer-free individuals, and a validation cohort of 39 lung cancer patients and 28 controls. In the development cohort, 7 of the 26 lncRNAs were reliably measured in plasma. Two (SNHG1 and RMRP) displayed a considerably high plasma level in lung cancer patients vs. cancer-free controls (all P < .001). Combined use of the plasma lncRNAs as a biomarker signature produced 84.13% sensitivity and 87.88% specificity for diagnosis of lung cancer, independent of stage and histological type of lung tumor, and patients' age and sex (all P > .05). The diagnostic value of the plasma lncRNA signature for lung cancer early detection was confirmed in the validation cohort. The plasma lncRNA signature may provide a potential blood-based assay for diagnosing lung cancer at the early stage. Nevertheless, a prospective study is warranted to validate its clinical value.

A novel transforming growth factor beta-induced long noncoding RNA promotes an inflammatory microenvironment in human intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCCA) is a deadly liver primary cancer associated with poor prognosis and limited therapeutic opportunities. Active transforming growth factor beta (TGFβ) signaling is a hallmark of the iCCA microenvironment. However, the impact of TGFβ on the transcriptome of iCCA tumor cells has been poorly investigated. Here, we have identified a specific TGFβ signature of genes commonly deregulated in iCCA cell lines, namely HuCCT1 and Huh28. Novel coding and noncoding TGFβ targets were identified, including a TGFβ-induced long noncoding RNA (TLINC), formerly known as cancer susceptibility candidate 15 (CASC15). TLINC is a general target induced by TGFβ in hepatic and nonhepatic cell types. In iCCA cell lines, the expression of a long and short TLINC isoform was associated with an epithelial or mesenchymal phenotype, respectively. Both isoforms were detected in the nucleus and cytoplasm. The long isoform of TLINC was associated with a migratory phenotype in iCCA cell lines and with the induction of proinflammatory cytokines, including interleukin 8, both in vitro and in resected human iCCA. TLINC was also identified as a tumor marker expressed in both epithelial and stroma cells. In nontumor livers, TLINC was only expressed in specific portal areas with signs of ductular reaction and inflammation. Finally, we provide experimental evidence of circular isoforms of TLINC, both in iCCA cells treated with TGFβ and in resected human iCCA. Conclusion: We identify a novel TGFβ-induced long noncoding RNA up-regulated in human iCCA and associated with an inflammatory microenvironment. (Hepatology Communications 2018;2:254-269).

Long non-coding RNA ZEB2-AS1 promotes proliferation and inhibits apoptosis in human lung cancer cells

Lung cancer is among the leading causes of cancer-associated mortality worldwide, with a low 5-year survival rate of 16.1%. However, the underlying molecular mechanisms behind lung cancer tumorigenesis remain largely unknown. Long non-coding RNAs (lncRNAs) have been demonstrated to serve a function in the tumorigenesis of multiple types of cancer. The objective of the present study was to identify the function of a newly identified lncRNA zinc finger E-box-binding homeobox 2 antisense RNA 1 (ZEB2-AS1) in human lung cancer. Results demonstrated that the transcript level of ZEB2-AS1 in human lung cancer was markedly upregulated in vivo and in vitro. The knockdown of ZEB2-AS1 in A549 and NCI-H292 cells, and the overexpression of ZEB2-AS1 in H-125 and H1975 cells, altered colony formation and cell proliferative rate, as examined using colony formation and cell proliferation assays. Western blot analysis revealed that the knockdown of ZEB2-AS1 in A549 and NCI-H292 cells increased the protein levels of B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), caspase-3 and -9, upregulated the relative activities of caspase-3 and -9, and had no observable effect on caspase-8 activity. Similarly, the overexpression of ZEB2-AS1 in H-125 and H1975 cells resulted in decreased expression of caspase-3, caspase-9, Bcl-2 and Bax. The results identified the effects of lncRNA ZEB2-AS1 on lung cancer progression through promoting its proliferation and inhibiting cell apoptosis, indicating that ZEB2-AS1 may serve as a novel prognostic factor for the diagnosis and treatment of human lung cancer in the clinic.

hsa_circ_0013958: a circular RNA and potential novel biomarker for lung adenocarcinoma

Circular RNAs (circRNAs) are associated with cancer progression and metastasis, although little is known about their role in lung adenocarcinoma (LAC). In the present study, microarrays were first used to screen for tumour-specific circRNA candidates in LAC tissue. Thirty-nine circRNAs were found to be up-regulated and 20 were down-regulated (fold change > 2.0). Among them, hsa_circ_0013958 was further confirmed to be up-regulated in all of the LAC tissues, cells and plasma. In addition, hsa_circ_0013958 levels were associated with TNM stage (P = 0.009) and lymphatic metastasis (P = 0.006). The area under the receiver operating characteristic curve was 0.815 (95% confidence interval = 0.727-0.903; P < 0.001). In addition, to further illustrate the bioactivities of hsa_circ_0013958 in LAC, siRNA-mediated inhibition of hsa_circ_0013958 was performed in vitro. The results showed that hsa_circ_0013958 promoted cell proliferation and invasion and inhibited cell apoptosis in LAC. Moreover, hsa_circ_0013958 was identified as a sponge of miR-134, and thus it up-regulated oncogenic cyclin D1, which plays a pivotal role in the development of non-small cell lung cancer. In conclusion, our results suggested that hsa_circ_0013958 could be used as a potential non-invasive biomarker for the early detection and screening of LAC.

Long Non-coding RNAs and Their Roles in Non-small-cell Lung Cancer

As a leading cause of cancer deaths worldwide, lung cancer is a collection of diseases with diverse etiologies which can be broadly classified into small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC). Lung cancer is characterized by genomic and epigenomic alterations; however, mechanisms underlying lung tumorigenesis remain to be elucidated. Long non-coding RNAs (lncRNAs) are a group of non-coding RNAs that consist of ⩾200 nucleotides but possess low or no protein-coding potential. Accumulating evidence indicates that abnormal expression of lncRNAs is associated with tumorigenesis of various cancers, including lung cancer, through multiple biological mechanisms involving epigenetic, transcriptional, and post-transcriptional alterations. In this review, we highlight the expression and roles of lncRNAs in NSCLC and discuss their potential clinical applications as diagnostic or prognostic biomarkers, as well as therapeutic targets.

Differential expression profiles of long non-coding RNAs reveal potential biomarkers for identification of human gastric cancer

Gastric cancer (GC) is one of the most lethal malignancies worldwide. To reduce its high mortality, sensitive and specific biomarkers for early detection are urgently needed. Recent studies have reported that tumor-specific long non-coding RNAs (lncRNAs) seem to be potential biomarkers for the early diagnosis and treatment of cancer. In the present study, lncRNA and mRNA expression profiling of GC specimens and their paired adjacent non-cancerous tissues was performed. Differentially expressed lncRNAs and mRNAs were identified through microarray analysis. The function of differential mRNA was determined by gene ontology and pathway analysis and the functions of lncRNAs were studied by constructing a co-expression network to find the relationships with corresponding mRNAs. We connected the co-expression network, mRNA functions, and the results of the microarray profile differential expression and selected 14 significantly differentially expressed key lncRNAs and 21 key mRNAs. Quantitative RT-PCR (qRT-PCR) was conducted to verify these key RNAs in 50 newly diagnosed GC patients. The data showed that RP5-919F19, CTD-2541M15 and UCA1 was significantly higher expressed. AP000459, LOC101928316, RP11-167N4 and LINC01071 expression was significantly lower in 30 advanced GC tumor tissues than adjacent non-tumor tissues P<0.05. Then, we further validated the above significant differential expression candidate lncRNAs in 20 early stage GC patients. Results showed that CTD-2541M15 and UCA1 were significantly higher expressed, AP000459, LINC01071 and MEG3 expression was significantly lower in 20 early stage GC patient tumor tissues than adjacent non-tumor tissues (P<0.05). In addition, expression of these lncRNAs shows gradual upward trend from early stage GC to advanced GC. Furthermore, conditional logistic regression analysis revealed the aberrant expression of CTD-2541M15, UCA1 and MEG3 closely linked with GC. There is a set of differentially expressed lncRNAs in GC which may be associated with the progression and development of GC. The differential expression profiles of lncRNAs in GC may be promising biomarkers for the early detection and early screening of high‑risk populations.