Prognostic impact of Bcl-2 depends on tumor histology and expression of MALAT-1 lncRNA in non-small-cell lung cancer

Suppression of small nucleolar RNA host gene 8 (SNHG8) inhibits the progression of colorectal cancer cells

Colorectal cancer (CRC) is one of the most common gastrointestinal malignancies around the world with high mortality. Accumulating evidences demonstrate that long non-coding RNAs (lncRNAs) play critical roles in CRC tumorigenesis by regulating different pathways of carcinogenesis. SNHG8 (small nucleolar RNA host gene 8), a lncRNA, is highly expressed in several cancers and acts as an oncogene that promotes cancer progression. However, the oncogenic role of SNHG8 in CRC carcinogenesis and the underlying molecular mechanisms remain unknown. In this study, we explored the role of SNHG8 in CRC cell lines by performing a series of functional experiments. Similar to the data reported in the Encyclopedia of RNA Interactome, our RT-qPCR results showed that SNHG8 expression was significantly upregulated in CRC cell lines (DLD-1, HT-29, HCT-116, and SW480) compared to the normal colon cell line (CCD-112CoN). We performed dicer-substrate siRNA transfection to knockdown the expression of SNHG8 in HCT-116 and SW480 cell lines which were expressing high levels of SNHG8. SNHG8 knockdown significantly reduced CRC cell growth and proliferation by inducing autophagy and apoptosis pathways through the AKT/AMPK/mTOR axis. We performed wound healing migration assay and demonstrated that SNHG8 knockdown significantly increased migration index in both cell lines, indicating reduced migration abilities of cells. Further investigation showed that SNHG8 knockdown suppresses epithelial to mesenchymal transition and reduces cellular migratory properties of CRC cells. Taken together, our study suggests that SNHG8 acts as an oncogene in CRC through the mTOR-dependent autophagy, apoptosis, and EMT pathways. Our study provides a better understanding the role of SNHG8 in CRC at molecular level and SNHG8 might be used as novel therapeutic target for CRC management.

Oncogenic lncRNA MALAT-1 recruits E2F1 to upregulate RAD51 expression and thus promotes cell autophagy and tumor growth in non-small cell lung cancer

INTRODUCTION

LncRNA MALAT-1 expression is involved in regulating activities of non-small-cell lung cancer (NSCLC) cells. This study aimed to investigate the effects of lncRNA MALAT-1 on chemosensitivity of NSCLC cells by regulating autophagy.

METHODS

We first validated the expression of lncRNA MALAT-1 in NSCLC cell lines. NSCLC cell lines with high lncRNA MALAT-1 expression were exposed to doxorubicin (DOX) to assess chemosensitivity. Further LncMAP database retrieval and ChIP, RIP and luciferase activity assays were conducted to explore interplay between lncRNA MALAT-1, RAD51, and E2F1. Immunofluorescence staining was performed to evaluate formation of autophagosomes in NSCLC cells. Ectopic expression and knockdown methods were used for in vitro mechanism experiments and in vivo substantiation.

RESULTS

LncRNA MALAT-1 was overexpressed in NSCLC cells, and could promote NSCLC cell autophagy and inhibit its chemosensitivity. In vitro cell mechanism verification experiments showed that lncRNA MALAT-1 could recruit transcription factor E2F1 to bind to the promoter of RAD51, so as to promote the transcriptional expression of RAD51. In addition, cell function experiments in vitro showed that ectopically expressed lncRNA MALAT-1 promoted NSCLC cell autophagy and inhibited its chemosensitivity, while RAD51 knockdown negated its effect. Finally, in vivo animal experiments confirmed that lncRNA MALAT-1 silencing could impede the tumor growth.

CONCLUSIONS

Taken together, this study revealed that silencing lncRNA MALAT-1 enhanced chemosensitivity of NSCLC cells by promoting autophagy, highlighting a feasible approach to prevent chemoresistance in NSCLC treatment.

Small molecule targeting long noncoding RNA GAS5 administered intranasally improves neuronal insulin signaling and decreases neuroinflammation in an aged mouse model

Shifts in normal aging set stage for neurodegeneration and dementia affecting 1 in 10 adults. The study demonstrates that lncRNA GAS5 is decreased in aged and Alzheimer's disease brain. The role and targets of lncRNA GAS5 in the aging brain were elucidated using a GAS5-targeting small molecule NPC86, a frontier in lncRNA-targeting therapeutic. Robust techniques such as molecular dynamics simulation of NPC86 binding to GAS5, in vitro functional assays demonstrating that GAS5 regulates insulin signaling, neuronal survival, phosphorylation of tau, and neuroinflammation via toll-like receptors support the role of GAS5 in maintaining healthy neurons. The study demonstrates the safety and efficacy of intranasal NPC86 treatment in aged mice to improve cellular functions with transcriptomic analysis in response to NPC86. In summary, the study demonstrates that GAS5 contributes to pathways associated with neurodegeneration and NPC86 has tremendous therapeutic potential to prevent the advent of neurodegenerative diseases and dementias.

Long Noncoding RNA SNHG7 Is a Diagnostic and Prognostic Marker for Colon Adenocarcinoma

Numerous studies have shown that long noncoding RNAs (lncRNAs) play a critical role in the malignant progression of cancer. However, the potential involvement of lncRNAs in colon adenocarcinoma (COAD) remains unexplored. In this study, the expression of lncRNA SNHG7 in colon cancer tissues and its correlation with clinical characteristics were analyzed based on data from The Cancer Genome Atlas (TCGA) database. SNHG7 was found to be highly expressed in 17 types of cancer, including COAD. Next, TCGA data were further investigated to identify differentially expressed genes, and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed. In addition, the relationship between SNHG7 expression and clinical features were analyzed. SNHG7 expression was found to be a potentially valuable indicator for COAD diagnosis and prognosis. Finally, gene set enrichment analysis showed that SNHG7 may affect lupus erythematosus and reactome cellular senescence, possibly influencing the prognosis of patients with COAD. Altogether, these results suggest that SNHG7 may be associated with the occurrence and development of COAD, having potential diagnostic and prognostic value.

DUBR suppresses migration and invasion of human lung adenocarcinoma cells via ZBTB11-mediated inhibition of oxidative phosphorylation

Long noncoding RNAs (lncRNAs) are involved in a variety of cancers, but the role of LncRNA DUBR in lung adenocarcinoma (LUAD), the most prevalent form of lung cancer, remains unclear. In this study we investigated the expression of DUBR in LUAD to ascertain its association with the clinical pathology and prognosis of LUAD. Analysis of mRNA expression in The Cancer Genome Atlas (TCGA) LUAD database and in-house LUAD cohort (n = 94) showed that DUBR was significantly downregulated in LUAD, and was associated with poor prognosis. In LUAD cell lines (H1975, A549), overexpression of DUBR significantly suppressed the migration and invasion of the LUAD cells. We demonstrated that c-Myc could bind to the promoter of DUBR, and transcriptionally suppressed its expression. Knockdown of c-Myc almost completely blocked the invasion and migration of LUAD cells, whereas knockdown of DUBR partially rescued c-Myc-knockdown suppressed cell migration and invasion. Furthermore, DUBR overexpression significantly increased the expression of a downstream protein of DUBR, zinc finger, and BTB domain containing 11 (ZBTB11), in H1975 and A549 cells; knockdown of ZBTB11 partially rescued the DUBR-overexpression suppressed cell migration and invasion; knockdown of c-Myc significantly upregulated the expression of ZBTB11 in LUAD cells. Finally, we revealed that DUBR/ZBTB11 axis suppressed oxidative phosphorylation in LUAD cells. In short, we demonstrate that c-Myc/DUBR/ZBTB11 axis suppresses migration and invasion of LUAD by attenuating cell oxidative phosphorylation, which provides new insights into the regulatory mechanism of DUBR.

Norcycloartocarpin targets Akt and suppresses Akt-dependent survival and epithelial-mesenchymal transition in lung cancer cells

In searching for novel targeted therapeutic agents for lung cancer treatment, norcycloartocarpin from Artocarpus gomezianus was reported in this study to promisingly interacted with Akt and exerted the apoptosis induction and epithelial-to-mesenchymal transition suppression. Selective cytotoxic profile of norcycloartocarpin was evidenced with approximately 2-fold higher IC50 in normal dermal papilla cells (DPCs) compared with human lung cancer A549, H460, H23, and H292 cells. We found that norcycloartocarpin suppressed anchorage-independent growth, cell migration, invasion, filopodia formation, and decreased EMT in a dose-dependent manner at 24 h, which were correlated with reduced protein levels of N-cadherin, Vimentin, Slug, p-FAK, p-Akt, as well as Cdc42. In addition, norcycloartocarpin activated apoptosis caspase cascade associating with restoration of p53, down-regulated Bcl-2 and augmented Bax in A549 and H460 cells. Interestingly, norcycloartocarpin showed potential inhibitory role on protein kinase B (Akt) the up-stream dominant molecule controlling EMT and apoptosis. Computational molecular docking analysis further confirmed that norcycloartocarpin has the best binding affinity of -12.52 kcal/mol with Akt protein at its critical active site. As Akt has recently recognized as an attractive molecular target for therapeutic approaches, these findings support its use as a plant-derived anticancer agent in cancer therapy.

Stemness-Suppressive Effect of Bibenzyl from Dendrobium ellipsophyllum in Human Lung Cancer Stem-Like Cells

Cancer stem-like cells (CSCs) are key mediators driving tumor initiation, metastasis, therapeutic failure, and subsequent cancer relapse. Thus, targeting CSCs has recently emerged as a potential strategy to improve chemotherapy. In this study, the anticancer activity and stemness-regulating capacity of 4,5,4'-trihydroxy-3,3'-dimethoxybibenzyl (TDB), a bibenzyl extracted from Dendrobium ellipsophyllum, are revealed in CSCs of various human lung cancer cells. Culture with TDB (5-10 μM) strongly abolished tumor-initiating cells in lung cancer H460, H23, and A549 cells in both anchorage-dependent and anchorage-independent colony formation assays. Through the 3D single-spheroid formation model, attenuation of self-renewal capacity was observed in CSC-enriched populations treated with 1-10 μM TDB for 7 days. Flow cytometry analysis confirmed the attenuation of %cell overexpressing CD133, a CSC biomarker, in TDB-treated lung cancer spheroids. TDB at 5-10 μM remarkably suppressed regulatory signals of p-Akt/Akt, p-GSK3β/GSK3β, and β-catenin corresponding to the downregulated mRNA level of stemness transcription factors including Nanog, Oct4, and Sox2. Moreover, the antiapoptosis Bcl-2 and Mcl-1 proteins, which are downstream molecules of Akt signaling, were evidently decreased in CSC-enriched spheroids after culture with TDB (1-10 μM) for 24 h. Interestingly, the diminution of Akt expression by specific siAkt effectively reversed suppressive activity of TDB targeting on the CSC phenotype in human lung cancer cells. These findings provide promising evidence of the inhibitory effect of TDB against lung CSCs via suppression of Akt/GSK3β/β-catenin cascade and related proteins, which would facilitate the development of this bibenzyl natural compound as a novel CSC-targeted therapeutic approach for lung cancer treatment.

LINC00476 Suppresses the Progression of Non-Small Cell Lung Cancer by Inducing the Ubiquitination of SETDB1

Long non-coding RNAs are involved in the tumorigenesis of non-small cell lung cancer (NSCLC). Here we investigated whether LINC00476 affects the proliferation, invasion and migration of NSCLC cells via the SETDB1-activated Wnt/β-catenin pathway. The expression of LINC00476, SETDB1, Wnt1 and β-catenin were determined in NSCLC tumor tissues and the paired adjacent tissues, as well as in NSCLC cell lines and bronchial epithelioid cell lines. Cell proliferation, invasion and migration were determined using cell counting kit-8 assay and transwell assay. The relationship between LINC00476 and SETDB1 was elucidated using RNA pull-down, RNA immunoprecipitation and ubiquitination assays. LINC00476 was found to be significantly downregulated, while SETDB1, Wnt1 and β-catenin were upregulated in NSCLC tumor tissues and cell lines compared to the normal ones. Overexpression of LINC00476 promoted the proliferation, invasion and migration of NSCLC cells, and suppressed tumor growth in the mouse xenograft. Meanwhile, overexpression of LINC00476 induced the degradation of SETDB1 by promoting its ubiquitination. The simultaneous overexpression of LINC00476 and SETDB1 negated the inhibition of LINC00476 overexpression on the proliferation, invasion and migration of NSCLC cells. In conclusion, these findings indicate that LINC00476 acts as a tumor suppressor in NSCLC by downregulating SETDB1, which provides a novel target in the treatment of NSCLC.

Long non-coding RNA MALAT1 regulates trophoblast functions through VEGF/VEGFR1 signaling pathway

Preeclampsia, as one of the most serious pregnancy-specific diseases, manifested by high blood pressure and companied by proteinuria in pregnancy women after 20 gestational weeks. Although the underlying mechanism has been studied for decades, no unambiguous interpretation of this phenomenon was well recognized. Recent researches focused on long non-coding RNAs (lncRNAs) as key regulators of cancer cell proliferation, invasion, migration and angiogenesis. Tumor development and placenta implantation share several common biological behaviors. The expression of lncRNA MALAT1 was downregulated in the placenta of patients with severe preeclampsia. MALAT1 smart silencer significantly inhibited HTR-8/SVneo trophoblast cell proliferation, invasion, migration and tube formation in vitro. Moreover, MALAT1 inhibited the expression of angiogenic factors in umbilical vein endothelial cells co-cultured with trophoblasts. These results indicated that MALAT1 was involved in the pathogenesis of preeclampsia and might be a candidate biomarker as well as a therapeutic target for preeclampsia.

Long Non-Coding RNAs: Potential Biomarkers and Targets for Hepatocellular Carcinoma Therapy and Diagnosis

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide. Increasing studies showed that long non-coding RNAs (lncRNAs), a novel class of RNAs that are greater than 200 nucleotides in length but lack the ability to encode proteins, exert crucial roles in the occurrence and progression of HCC. LncRNAs promote the proliferation, migration, invasion, autophagy, and apoptosis of tumor cells by regulating downstream target gene expression and cancer-related signaling pathways. Meanwhile, lncRNA can be used as biomarkers to predict the efficacy of HCC treatment strategies, such as surgery, radiotherapy, chemotherapy, and immunotherapy, and as a potential individualized tool for HCC diagnosis and treatment. In this review, we overview up-to-date findings on lncRNAs as potential biomarkers for HCC surgery, radiotherapy, chemotherapy resistance, target therapy, and immunotherapy, and discuss the potential clinical application of lncRNA as tools for HCC diagnosis and treatment.

LncRNA MALAT1 Aggravates the Progression of Non-Small Cell Lung Cancer by Stimulating the Expression of COMMD8 via Targeting miR-613

Background

Non-small cell lung cancer (NSCLC) is a common malignant tumor in humans. Long non-coding RNA (lncRNA) involved in cancer progression has been reported frequently. The objective of this study was to investigate the role of lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) and explore a novel mechanism in NSCLC development.

Materials and Methods

The expression of MALAT1, copper metabolism MURR1 domain-containing 8 (COMMD8) and microRNA-613 (miR-613) was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The protein levels of COMMD8, Cyclin D1, Ki67, B cell lymphoma/leukemia-2 (Bcl-2), Bcl-2 associated X protein (Bax), lactate dehydrogenase A (LDHA), CD63 and CD81 were determined by Western blot. Cell proliferation, the number of colonies and cell apoptosis were assessed by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT), colony formation and flow cytometry assays, respectively. Glycolysis was distinguished based on glucose consumption, lactate production and LDHA activity. The role of MALAT1 in vivo was verified by animal experiments. The relationship between miR-613 and MALAT1 or COMMD8 was predicted by the bioinformatics tool starbase and verified by dual-luciferase reporter assay. The exosomes were isolated using the corresponding kit and identified by transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA).

Results

MALAT1 and COMMD8 were aberrantly upregulated in NSCLC tissues and cells. MALAT1 or COMMD8 knockdown blocked cell proliferation, colony formation and glycolysis but accelerated cell apoptosis in vitro. Besides, MALAT1 knockdown reduced tumor growth in vivo. We found that miR-613 was a target of MALAT1, and miR-613 could bind to the 3ʹ untranslated region (3ʹUTR) of COMMD8. MALAT1 regulated the expression of COMMD8 by absorbing miR-613. Moreover, the extracellular MALAT1 was transmitted by wrapping into exosomes.

Conclusion

MALAT1 promoted malignant activities of NSCLC cells through targeting miR-613/COMMD8 axis, and exosome-mediated transfer of NSCLC might be a novel approach for NSCLC treatment.

Identification of a 4-lncRNA signature predicting prognosis of patients with non-small cell lung cancer: a multicenter study in China

Background

Previous findings have indicated that the tumor, nodes, and metastases (TNM) staging system is not sufficient to accurately predict survival outcomes in patients with non-small lung carcinoma (NSCLC). Thus, this study aims to identify a long non-coding RNA (lncRNA) signature for predicting survival in patients with NSCLC and to provide additional prognostic information to TNM staging system.

Methods

Patients with NSCLC were recruited from a hospital and divided into a discovery cohort (n = 194) and validation cohort (n = 172), and detected using a custom lncRNA microarray. Another 73 NSCLC cases obtained from a different hospital (an independent validation cohort) were examined with qRT-PCR. Differentially expressed lncRNAs were determined with the Significance Analysis of Microarrays program, from which lncRNAs associated with survival were identified using Cox regression in the discovery cohort. These prognostic lncRNAs were employed to construct a prognostic signature with a risk-score method. Then, the utility of the prognostic signature was confirmed using the validation cohort and the independent cohort.

Results

In the discovery cohort, we identified 305 lncRNAs that were differentially expressed between the NSCLC tissues and matched, adjacent normal lung tissues, of which 15 are associated with survival; a 4-lncRNA prognostic signature was identified from the 15 survival lncRNAs, which was significantly correlated with survivals of NSCLC patients. This signature was further validated in the validation cohort and independent validation cohort. Moreover, multivariate Cox analysis demonstrates that the 4-lncRNA signature is an independent survival predictor. Then we established a new risk-score model by combining 4-lncRNA signature and TNM staging stage. The receiver operating characteristics (ROC) curve indicates that the prognostic value of the combined model is significantly higher than that of the TNM stage alone, in all the cohorts.

Conclusions

In this study, we identified a 4-lncRNA signature that may be a powerful prognosis biomarker and can provide additional survival information to the TNM staging system.

DNA damage/cGAS-triggered up-regulation of MALAT1 promotes undesirable inflammatory responses in radiotherapy of cancer

Radiotherapy is the most common strategy for treating cancer. However, the radiation-induced inflammatory responses, acute or chronic, in the normal tissues of the irradiated region may result in undesirable side effects, such as lung injury and atherosclerosis. MALAT1 is believed to function in the onset, development, progression and metastasis of various cancers. Silencing MALAT1 may be a promising treatment for rescuing cancer. Nevertheless, whether MALAT1 promotes the radiation-induced undesirable inflammatory response is still uncovered. The present study reveals that radiation-induced DNA damage triggers cGAS signaling and subsequently increases the expression of MALAT1. Overexpression of MALAT1 inhibits the function of miR146a in the suppression of STAT1, which results in the boost of adhesion molecules and eventually induces acute lung injury and atherosclerosis. Thus, silencing MALAT1 may facilitate the reduction of radiation-induced acute and chronic complications in the radiotherapy of cancer.

High expression of lncRNA-SNHG7 is associated with poor prognosis in hepatocellular carcinoma

Expression of long non-coding RNA SNHG7 (lncRNA-SNHG7) and its clinical significance in hepatocellular carcinoma (HCC) were explored. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression level of lncRNA-SNHG7 in cancer tissues. Kaplan-Meier curves and multivariate Cox proportional models were used to study the impact on clinical outcome. Expression of lncRNA-SNHG7 was much higher in cancer tissues than that in para-cancer tissues. The lncRNA-SNHG7 expression was correlated with tumor number, lymph node metastasis and clinical stage (P<0.05). In addition, HCC patients with higher lncRNA-SNHG7 expression had significantly poorer progression-free survival time and overall survival time (P<0.001). Both univariate analysis and multivariate analysis indicated that high expression of lncRNA-SNHG7 was an independent predictor of poor prognosis in HCC. LncRNA-SNHG7 might contribute to the development of HCC and serve as a clinical biomarker and a therapeutic target for HCC patients.

Long Noncoding RNA COPDA1 Promotes Airway Smooth Muscle Cell Proliferation in Chronic Obstructive Pulmonary Disease

Abnormal expression of long noncoding RNAs (lncRNAs) has been confirmed to be associated with many diseases, including chronic obstructive pulmonary disease (COPD). To gain better understanding of the mechanism of COPD, we investigated the lncRNA and mRNA profiles in the lung tissue of patients with COPD. According to the analysis, one of the significantly different lncRNAs, COPDA1, might participate in the occurrence and development of COPD. Lung tissues were collected from nonsmokers, smokers, or smokers with COPD for RNA sequencing. Bioinformatic analysis and cell experiments were used to define the function of COPDA1, and the effects of COPDA1 on intracellular Ca²⁺ concentration and cell proliferation were examined after knockdown or overexpression of COPDA1. A number of variations of lncRNAs were found in the comparison of nonsmokers, smokers, and smokers with COPD. GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analyses indicated that smoking was involved in the activation of cytokines and the cell cycle, which is associated with COPD. According to the lncRNA-mRNA-coexpressing network and enrichment analysis, COPDAz1 and one of its target genes, MS4A1 (membrane-spanning 4-domains family, subfamily A) were investigated, and we discovered that the expression of MS4A1 was closely associated with lncRNA COPDA1 expression in human bronchial smooth muscle cells (HBSMCs). Further study showed that lncRNA COPDA1 upregulated the expression of MS4A1 to increase store-operated calcium entry in the HBSMCs, resulting in the promotion of the proliferation of smooth muscle cells as well as of airway remodeling. COPDA1 might be involved in the regulation of certain signaling pathways in COPD, might promote the proliferation of HBSMCs, and might also be involved in facilitating airway remodeling.

Long non-coding RNAs as the critical factors during tumor progressions among Iranian population: an overview

BACKGROUND

Cancer is associated with various genetic and environmental risk factors. Beside the mutations or aberrant expression of protein-coding genes, the genetic deregulation of non-coding RNAs has also an important role during tumor progression and metastasis. Long non-coding RNAs (lncRNAs) are a class of ncRNAs larger than 200 nucleotides that may function as tumor-suppressor or oncogene.

MAIN BODY

There is a raising trend of cancer incidence among Iranian population during the last decades. Therefore, it is required to prepare a general population specific panel of genetic markers for the early detection of cancer in this population. The tissue-specific expression characteristics and high stability in body fluids highlight the lncRNAs as efficient diagnostic and prognostic noninvasive biomarkers in cancer. In present review we summarized all of the lncRNAs which have been reported until now in different tumors among Iranian patients.

CONCLUSIONS

This review paves the way of introducing a population based noninvasive diagnostic panel of lncRNAs for the early detection of tumor cells among Iranian population.

Long non-coding RNAs in non-small cell lung cancer: functions and distinctions from other malignancies

Lung cancer leads to the most cancer-related death in the world. It was shown from the increasing evidences that long non-coding RNAs (lncRNAs) are emerging as molecules for diagnosis, prognosis and even therapy of lung cancer and other malignancies. The biological functions or involved signaling pathways of lncRNAs are always found to be inconsistent among different types of malignancies. However, no available literature has systemically summarized differences in the functions and underlying molecular mechanisms of lncRNAs between lung cancer and other cancers. In this review, the biological functions and molecular mechanisms of lncRNAs in lung cancer were introduced. Furthermore, their functional differences between lung cancer and other malignancies were discussed. Finally, their potential clinical applications in future lung cancer therapy were focused on.

LncRNA TP73-AS1 interacted with miR-141-3p to promote the proliferation of non-small cell lung cancer

INTRODUCTION

Recent studies have shown that long non-coding RNAs (lncRNAs) are involved in a variety of biological processes and diseases in humans, including cancer. However, the exact effects and molecular mechanisms of TP73-AS1 in non-small cell lung cancer (NSCLC) progression are still unknown. The present study is aimed to reveal the detailed functions and the mechanism of TP73-AS1 in the regulation of NSCLC cell proliferation.

MATERIAL AND METHODS

TP73-AS1 expression in NSCLC tissues and cell lines was determined using real-time PCR assays. The functions of TP73-AS1 in the regulation of NSCLC cell proliferation was evaluated using BrdU assays. The interaction between TP73-AS1 and miR-141-3p was confirmed using luciferase report gene assays.

RESULTS

TP73-AS1 was upregulated in NSCLC tissues and cell lines. However, when knockdown of TP73-AS1 inhibited the NSCLC proliferation. By using online tools, we screened out miR-141-3p may combined with TP73-AS1. With use of luciferase assays, we confirmed that miR-141-3p could directly bind to TP73-AS1. In NSCLC tissues, miR-141-3p was down-regulated; TP73-AS1 was inversely correlated with miR-141-3p.

CONCLUSIONS

Our data suggest that TP73-AS1 might be an oncogenic lncRNA that promotes proliferation of NSCLC and might be regarded as a therapeutic target in NSCLC.

Downregulated long non-coding RNA LINC00899 inhibits invasion and migration of spinal ependymoma cells via RBL2-dependent FoxO pathway

This study is aimed to clarify the potential role of lncRNA LINC00899 in invasion and migration of spinal ependymoma cells through the FoxO pathway via RBL2. Spinal ependymoma related chip data (GSE50161 and GSE66354) was initially downloaded and differentially expressed lncRNAs were screened out. Fifty-eight cases of spinal ependymoma and normal ependymal tissues were collected. The effects of LINC00899 and RBL2 on the spinal ependymoma cell migration and invasion were determined using the third generation spinal ependymoma cells and transfection with LINC00899 vector, siRNA-LINC00899 and siRNA-RBL2. The expression of LINC00899, pathway and cell proliferation- and apoptosis-related factors was determined. Finally, we also detected cell proliferation, migration, invasion, cycle and apoptosis after transfection. Our results showed that LINC00899 was up-regulated in spinal ependymoma and RBL2 was confirmed as a target gene of LINC00899 and found to be involved in regulation of FoxO pathway. LINC00899 expression increased in spinal ependymoma tissues whereas RBL2 expression decreased. Moreover, we found that siRNA-LINC00899 could elevate RBL2, p21, p27 and Bax levels, decrease FoxO, Bcl-2, Vimentin, Annexin levels, reduced cell proliferation, migration and invasion and enhanced apoptosis. Taken together, our study suggests that down-regulated LINC00899 exerts anti-oncogenic effects on spinal ependymoma via RBL2-dependent FoxO, which provides a novel therapeutic target for the treatment of spinal ependymomas.

SFTA1P, LINC00968, GATA6-AS1, TBX5-AS1, and FEZF1-AS1 are crucial long non-coding RNAs associated with the prognosis of lung squamous cell carcinoma

Lung cancer has high incidence and mortality rates, and lung squamous cell carcinoma (LUSC) is a common form of non-small-cell lung carcinoma (NSCLC). The aim of our study was to discover long non-coding RNAs (lncRNAs) associated with LUSC prognosis. RNA-sequencing data obtained from LUSC samples were extracted from The Cancer Genome Atlas database. Using the limma package, differentially expressed genes (DEGs; including differentially expressed lncRNA genes (DELs), coding genes (DECs), and other genes (DEOs)) between LUSC and control samples were analyzed. Using Kaplan-Meier survival analysis, prognosis-associated lncRNAs were further selected. Following the calculation of Pearson's correlation coefficients between DELs and other DEGs, the DEL-DEG co-expression network was visualized using Cytoscape software. Using the clusterProfiler package, potential functions for DECs co-expressed with DELs were predicted. There were 1,305 DEGs in LUSC samples, including 153 DELs, 1,109 DECs, and 43 DEOs. Based on survival analysis, 22 prognosis-associated lncRNAs (including surfactant associated 1, pseudogene (SFTA1P), long intergenic non-protein coding RNA 968 (LINC00968), GATA6 antisense RNA 1, (GATA6-AS1) TBX5 antisense RNA 1 (TBX5-AS1) and FEZF1 antisense RNA 1 (FEZF1-AS1)) in LUSC were selected from these DELs, and the associated abnormal expression levels were also verified in LUSC clinical samples. A DEL-DEG co-expression network was constructed, which involved 93 DELs. Co-expressed DECs were enriched for only 8 prognosis-associated DELs, including LINC00968, SFTA1P, and TBX5-AS1. Specifically, mitogen-activated protein kinase (MAPK) signaling pathway-associated genes were enriched in DECs co-expressed with LINC00968, SFTA1P, GATA6-AS1, TBX5-AS1 and FEZF1-AS1, which may be prognosis-associated lncRNAs in LUSC. In addition, LINC00968 may affect the outcome of patients with LUSC via the MAPK signaling pathway.

Hypoxia inducible factor-1α/B-cell lymphoma 2 signaling impacts radiosensitivity of H1299 non-small cell lung cancer cells in a normoxic environment

Hypoxia inducible factor-1α (HIF-1α) is a critical transcriptional factor for the response of cells to hypoxic microenvironment and its expression induces resistance of hypoxic non-small-cell lung cancer (NSCLC) cells to radiotherapy. This study investigated how the activation of HIF-1α/B-cell lymphoma 2 (BCL-2) signaling under normoxic conditions impacted radiosensitivity of NSCLC cells. The recombinant pcDNA3.0-EGFP plasmids with wild-type or mutant HIF-1α complementary DNA (cDNA) were transfected into H1299 cells, an NSCLC cell line, establishing two H1299 sublines with high expression of HIF-1α. Compared with the levels of HIF-1α and BCL-2 proteins in non-transfected cells, increased levels of both proteins were found in transfected cells. Moreover, the expression of HIF-1α in non-transfected cells induced by chloride cobalt (CoCl₂), a commonly used mimetic hypoxia reagent, was concomitant with the enhancement of BCL-2 expression. Conversely, reduction of HIF-1α expression by an inhibitor decreased the levels of BCL-2 proteins. The results revealed that the stabilization and expression of HIF-1α promoted the accumulation of BCL-2 proteins in H1299 cells. Subsequent experiments showed that intracellular HIF-1α/BCL-2 signaling was triggered in a normoxic environment after H1299 cells were exposed to irradiation, causing an elevated radioresistance. In contrast, blockage of HIF-1α/BCL-2 signaling leads to an elevated radiosensitivity. Proliferation of cells assay showed that, under normoxic conditions, population doubling times (PDTs) of irradiated cells were prolonged by suppression of HIF-1α/BCL-2 signaling. It is, therefore, indicated that HIF-1α/BCL-2 signaling activated by ionizing radiation reduces the radiosensitivity of H1299 cells independent of the hypoxic environment.

Long noncoding RNA ENST00000413528 sponges microRNA-593-5p to modulate human glioma growth via polo-like kinase 1

AIMS

In this study, we examined the expression of lncRNA ENST00000413528 in glioma and determined its role in glioma development.

METHODS

LncRNA ENST00000413528 was detected in glioma tissues by lncRNA microarray. Then, we performed real-time PCR, CCK-8, colony formation assay, flow cytometry, caspase-3/7 assay and animal experiment to detect the function of ENST00000413528 in glioma after ENST00000413528 knockdown. Subsequent bioinformatics analysis, luciferase reporter assays and RNA immunoprecipitation (RIP) assay western blotting indicated possible downstream regulatory molecules. The expression of PLK1 in glioma tissues was also examined by immunohistochemistry staining.

RESULTS

Expression of ENST00000413528 was significantly increased in glioma tissues and LN229 and U251 cells. PLK1 protein could not be detected in peritumoral brain edema (PTBE) tissues; however, it showed an increasing number of positively cytoplasmic stained from WHO-Grade II to Grade III gliomas. Knockdown of ENST00000413528 in glioma cells inhibited cell proliferation and colony formation abilities, induced the G0/G1 arrest of the cell cycle, and promoted apoptosis. The dual reporter assay and RNA immunoprecipitation assay verified the interaction between ENST00000413528 and miR-593. We also demonstrated that polo-like kinase 1 (PLK1) was regulated by miR-593; PLK1 messenger RNA lacking 3'UTR partially reversed the effects caused by ENST00000413528 knockdown or miR-593 upregulation.

CONCLUSION

lncRNA ENST00000413528 is closely related to the development of glioma via the miR-593-5p/PLK1 pathway.

LncRNA GASL1 inhibits growth and promotes expression of apoptosis-associated proteins in prostate carcinoma cells through GLUT-1

Growth-arrest-associated long non-coding (lnc)RNA 1 (GASL1) is as newly identified lncRNA that is associated with liver cancer. The present study aimed to investigate the role of GASL1 in prostate carcinoma (PC). Expression levels of GASL1 in prostate tissues and sera from patients with PC and from healthy subjects were detected by reverse transcription-quantitative polymerase chain reaction. Receiver operating characteristic and survival curve analyses were performed to evaluate the diagnostic and prognostic values of GASL1 for patients with PC. A GASL1 expression vector was transfected into PC cells prior to assessment of cell proliferation and expression of B cell lymphoma 2 (Bcl-2) and glucose transporter 1 (GLUT-1) by Cell Counting Kit-8 and western blotting, respectively. The results demonstrated that GASL1 was significantly downregulated in the tissue and serum of patients with PC compared to those of healthy subjects. In addition, GASL1 was used to distinguish patients with PC from healthy controls, and low expression levels of GASL1 were associated with short survival time. Expression levels of GASL1 were significantly associated with tumor size. GASL1 overexpression inhibited PC cell growth. Overexpression of GASL1 upregulated Bcl-2 expression and downregulated GLUT-1 expression. In conclusion, these data suggested that lncRNA GASL1 may inhibit PC cell proliferation by targeting GLUT-1.

Stabilization of lncRNA GAS5 by a Small Molecule and Its Implications in Diabetic Adipocytes

Long noncoding RNA (lncRNA) are regulatory RNAs >200 nt. We previously showed that lncRNA GAS5 decreases significantly in serum of type 2 diabetes mellitus (T2DM) patients. Hence, we sought to decipher the molecular mechanisms underlying the role of GAS5 in T2DM in adipose tissue. Using CHIP-RIP, we demonstrate that GAS5 binds to promoter of insulin receptor to regulate its expression, and its depletion inhibits glucose uptake and insulin signaling. Toward stabilizing GAS5 levels in T2DM, we incorporated a strategy to limit the degradation of GAS5 by blocking the interaction of GAS5 and UPF1 with a small molecule identified using OBTC screening strategy. NP-C86 binds to GAS5 with high affinity, and increases GAS5 levels and glucose uptake in diabetic patient adipocytes. As a broader impact, NP-C86 may be used as a molecular probe to investigate the intricacies of GAS5 in relevant biological systems as it offers specificity, efficient cellular uptake and is non-cytotoxic.

Overexpression of AR-regulated lncRNA TMPO-AS1 correlates with tumor progression and poor prognosis in prostate cancer

BACKGROUND

Prostate cancer (PCa) is a leading cause of death in males all over the world; besides, the diagnosis and therapy of it are still challenging. Researchers have revealed that long non-coding RNAs (lncRNAs) play important roles in the genesis and progression of human cancers, including PCa.

METHODS

Bioinformatics analysis and Kaplan-Meier survival analysis were utilized to confirm TMPO-AS1 as a diagnostic and prognostic marker. The TMPO-AS1 levels in both patient tissues and PCa cell lines were determined by qRT-PCR analysis. Moreover, the chromatin immunoprecipitation (ChIP) assay identified that TMPO-AS1 was a direct target of AR. The effect of overexpression or knockdown of TMPO-AS1 on cell proliferation, migration, cell cycle, and cell apoptosis was assessed by using CCK-8, transwell assays, and flow cytometric analysis, respectively.

RESULTS

Based on primary screening, we found that TMPO-AS1 could be a useful diagnostic and prognostic marker for PCa, whose expression was upregulated in PCa samples and associated with poorer prognosis. Bioinformatics predictions revealed TMPO-AS1 was associated with a series of biological processes involved in PCa progression. In PCa cells, TMPO-AS1 was predominantly localized in the cytoplasm and directly down-regulated by AR. Gain/loss-of-function assays showed TMPO-AS1 overexpression increased cell proliferation by promoting cell cycle progression and promoted migration, but reduced apoptosis of PCa cells. In addition, TMPO-AS1 may be a diagnostic and prognostic marker in multiple cancer types.

CONCLUSIONS

AR-regulated lncRNA TMPO-AS1 functioned as an oncogenic lncRNA in PCa, and may be a potential diagnostic and prognostic biomarker to be used as a therapeutic target for PCa.

Long noncoding RNA MALAT1 in exosomes drives regenerative function and modulates inflammation-linked networks following traumatic brain injury

BACKGROUND

Neuroinflammation is a common therapeutic target for traumatic brain injury (TBI) due to its contribution to delayed secondary cell death and has the potential to occur for years after the initial insult. Exosomes from adipose-derived stem cells (hASCs) containing the long noncoding RNA MALAT1 are a novel, cell-free regenerative approach to long-term recovery after traumatic brain injury (TBI) that have the potential to modulate inflammation at the genomic level. The long noncoding RNA MALAT1 has been shown to be an important component of the secretome of hASCs.

METHODS

We isolated exosomes from hASC containing or depleted of MALAT1. The hASC-derived exosomes were then administered intravenously to rats following a mild controlled cortical impact (CCI). We followed the rats with behavior, in vivo imaging, histology, and RNA sequencing (RNA Seq).

RESULTS

Using in vivo imaging, we show that exosomes migrate into the spleen within 1 h following administration and enter the brain several hours later following TBI. Significant recovery of function on motor behavior as well as a reduction in cortical brain injury was observed after TBI in rats treated with exosomes. Treatment with either exosomes depleted of MALAT1 or conditioned media depleted of exosomes showed limited regenerative effects, demonstrating the importance of MALAT1 in exosome-mediated recovery. Analysis of the brain and spleen transcriptome using RNA Seq showed MALAT1-dependent modulation of inflammation-related pathways, cell cycle, cell death, and regenerative molecular pathways. Importantly, our data demonstrates that MALAT1 regulates expression of other noncoding RNAs including snoRNAs.

CONCLUSION

We demonstrate that MALAT1 in hASC-derived exosomes modulates multiple therapeutic targets, including inflammation, and has tremendous therapeutic potential for treatment of TBI.

Inhibition of MALAT1 sensitizes liver cancer cells to 5-flurouracil by regulating apoptosis through IKKα/NF-κB pathway

Metastasis associated lung adenocarcinoma transcript 1 (MALAT1) is involved in tumor cell growth process. However, its role and molecular mechanism in liver cancer is still not fully understood. In this study, we found that MALAT1 was significantly expressed in liver cancer cell lines. And knockdown of MALAT1 suppressed proliferation, migration and invasion of HepG2 cells, accompanied with decrease of Rho-associated coiled-coil-forming protein kinase 1 (ROCK1), α-smooth muscle actin (α-SMA), N-cadherin, Vimentin and TWIST. Significantly, MALAT1 deletion sensitized HepG2 cells to 5-FU-induced cell cycle arrest in G1 phase, as evidenced by the significant reduction in Cyclin D1 and CDK4 and increase in p53, p21 and p27 protein levels. In addition, MALAT1 knockdown triggered 5-FU induced apoptosis in HepG2 cells by inducing intrinsic apoptosis-related signals, including Cyto-c, Apaf-1, cleaved Caspase-9/-7/-3 and poly (ADP-ribose) polymerase (PARP). Furthermore, phosphorylated nuclear factor-κB (p-NF-κB) was also down-regulated by MALAT1 silence. Importantly, suppression of IKKα/NF-κB significantly elevated apoptosis and reduced liver cancer cell viability in MALAT1-knockdown cells with 5-FU incubation. The nude mice transplantation model also confirmed the promoted sensitivity of MALAT1-silenced HepG2 cells to 5-FU by blocking tumor cell proliferation and inducing apoptosis. Therefore, our data supplied a potential mechanism by which knockdown of MALAT1 might play an important role in augmenting sensitivity of HepG2 cells to 5-FU in therapeutic approaches, demonstrating suppressing of MALAT1 may serve as a combination with chemotherapeutic agents in liver cancer treatment.

MALAT1: A long non-coding RNA highly associated with human cancers

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a well-known lncRNA associated with numerous diseases, particularly cancer, has received increased attention. The expression of MALAT1 was determined to be upregulated in numerous types of tumors and MALAT1 exhibited effects on tumor cell proliferation, migration, invasion and apoptosis. The abnormal expression of MALAT1 was identified in almost in every organ of the digestive system. MALAT1 performed an important role in the pathological alterations of organs that are associated with sex hormones and several reproductive system cancers. MALAT1 participates in molecular pathways. In the clinical application of MALAT1, MALAT1 was considered as a potential biomarker for the diagnosis and prediction of cancers, and may also serve as therapeutic target for treatment of specific tumors. This review summarizes the abnormal expression of MALAT1 in cancer, its significant effect on the primary features of cancer, as well as the underlying molecular mechanisms of MALAT1 in various cancers. According to studies on MALAT1, we introduce the upstream and downstream substances associated with the function of MALAT1. These reviewed studies promote the clinical application of MALAT1 in the aspect of diagnosis and treatment of different cancers, and may help point out new study directions for MALAT1.

Expression of metastasis-associated lung adenocarcinoma transcript 1 long non-coding RNA in vitro and in patients with non-small cell lung cancer

The present study aimed to investigate the association between the expression of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) long non-coding RNA (lncRNA) and the recurrence of non-small cell lung cancer (NSCLC) and to elucidate the potential mechanisms of MALAT1 in vitro. Between 1 June 1, 2010 and December 30, 2016, NSCLC tumor tissues and adjacent non-cancerous tissues were obtained from 120 patients with NSCLC, who had undergone surgical resection at Taizhou Hospital of Wenzhou Medical University (Linhai, China). The total RNA of tissues and cells were extracted and the expression of MALAT1 was determined using a wound healing assay and reverse transcription quantitative polymerase chain reaction. In addition, MALAT1 expression in A549 cells was silenced using small interfering RNA. The proliferation, migration and invasion of cells were then assessed using a CellTiter 96 kit and Transwell assays. MALAT1 expression was significantly increased in NSCLC samples compared with expression in adjacent non-cancerous tissues. Furthermore, the expression of MALAT1 in patients with NSCLC that exhibited recurrence was markedly higher than in those that did not. The results of the present study also demonstrated significant associations between high expression of MALAT1 and female sex, Tumor-Node-Metastasis advanced stage, vessel invasion, pathological differentiation and recurrence of patients with NSCLC. The proliferative, migratory and invasive abilities of MALAT1-silenced A549 cells were significantly decreased compared with those of control cells. MALAT1 expression was significantly increased in NSCLC tissues and was revealed to serve a role in the progression of NSCLC.

Deciphering the roles of lncRNAs in breast development and disease

Breast cancer is the second leading cause of cancer related deaths in women. It is therefore important to understand the mechanisms underlying breast cancer development as well as raises the need for enhanced, non-invasive strategies for novel prognostic and diagnostic methods. The emergence of long non-coding RNAs (lncRNAs) as potential key players in neoplastic disease has received considerable attention over the past few years. This relatively new class of molecular regulators has been shown from ongoing research to act as critical players for key biological processes. Deregulated expression levels of lncRNAs have been observed in a number of cancers including breast cancer. Furthermore, lncRNAs have been linked to breast cancer initiation, progression, metastases and to limit sensitivity to certain targeted therapeutics. In this review we provide an update on the lncRNAs associated with breast cancer and mammary gland development and illustrate the versatility of such lncRNAs in gene control, differentiation and development both in normal physiological conditions and in diseased states. We also highlight the therapeutic and diagnostic potential of lncRNAs in cancer.

A bibenzyl from Dendrobium ellipsophyllum induces apoptosis in human lung cancer cells

Failure of current chemotherapeutic drugs leads to the recurrence of tumor pathology and mortality in lung cancer patients. This study aimed to evaluate the anticancer activity and related mechanisms of 4,5,4'-trihydroxy-3,3'-dimethoxybibenzyl (TDB), a bibenzyl extracted from Dendrobium ellipsophyllum Tang and Wang, in human lung cancer cells. Cytotoxicity of TDB (0-300 µM) in different types of human lung cancer cells (H460, H292 and H23) and human dermal papilla cells (DPCs) was evaluated via MTT viability assay. Selective anticancer activity of TDB against human lung cancer cells was demonstrated with a high IC₅₀ (approximately > 300 µM) in DPCs, while IC₅₀ in human lung cancer H460, H292 and H23 cells was approximately 100 ± 5.18, 100 ± 8.73 and 188.89 ± 8.30 µM, respectively. After treatment with 50 µM of TDB for 24 h, flow cytometry analysis revealed the significant increase of early and late apoptosis with absence of necrosis cell death in human lung cancer cells. The up-regulation of p53, a tumor-suppressor protein, was elucidated in human lung cancer cells treated with 10-50 µM of TDB. Alteration to down-stream signaling of p53 including activation of pro-apoptosis protein (Bcl-2-associated X protein; Bax), reduction of anti-apoptosis (B cell lymphoma 2; Bcl-2 and myeloid cell leukemia 1; Mcl-1) and suppression on protein kinase B (Akt) survival pathway were notified in TDB-treated lung cancer cells. The information obtained from this study strengthens the potential development of TDB as an anticancer compound with a favorable human safety profile and high efficacy.

MALAT1/miR-101-3p/MCL1 axis mediates cisplatin resistance in lung cancer

In this study, we investigated the mechanism by which lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) mediates cisplatin resistance in lung cancer. Lung cancer patients with high MALAT1 levels were associated with cisplatin resistance and low overall survival. Moreover, cisplatin-resistant A549/DDP cells showed higher MALAT1 expression than cisplatin-sensitive lung cancer cells (A549, H460, H1299 and SPC-A1). Dual luciferase reporter and RNA immunoprecipitation assays showed direct binding of miR-101-3p to MALAT1. MALAT1 knockdown in lung cancer cells resulted in miR-101-3p upregulation and increased cisplatin sensitivity. In addition, miR-101-3p decreased myeloid cell leukemia 1 (MCL1) expression by binding to the 3’-untranslated region (3’-UTR) of its mRNA. These results demonstrate that MALAT1/miR-101-3p/MCL1 signaling underlies cisplatin resistance in lung cancer.

Circulating long non-coding RNA MALAT1 expression as molecular biomarker in Egyptian patients with breast cancer

The abnormal contribution of long non-coding RNA (lncRNAs) expression to human tumorigenesis is still a matter of debate. Breast cancer is the most common cancer in females; it represents a terrible problem in our country. The aim of this research was to assess the role of MALAT1, as one of lncRNAs, as a potential biomarker in breast cancer. This study comprised 80 patients with breast cancer and 80 controls. MALAT1 expression was measured by RT-quantitative polymerase chain reaction (qPCR). CA15-3 was estimated using chemiluminescence immunoassay (CLIA). MALAT1 expression was significantly elevated in breast cancer cases compared to controls (P < 0.0001). By performing the ROC curve analysis, we assumed that the diagnostic sensitivity and specificity for breast cancer were 83.7% and 81.2%, respectively for MALAT1 expression and 77.5% and 82.5% respectively for CA15-3 level. Moreover, combination analysis of the 2 parameters improved the diagnostic sensitivity of CA15-3 in breast cancer. In conclusion, MALAT1 expression level was positively correlated with lymph node status, estrogen receptor (ER), tumor stage and histological grade indicating its possible prognostic value. MALAT1 expression can be used as an accurate marker for diagnosis of breast cancer, in addition it possesses a prognostic value of such disease.

HOXD-AS1 functions as an oncogenic ceRNA to promote NSCLC cell progression by sequestering miR-147a

Non-small cell lung cancer (NSCLC) is one of the most common malignancies worldwide, and it occurs at a higher frequency in males. HOXD-AS1, an important cancer-associated long noncoding RNA (lncRNA), contributes to the development and progression of several cancers. However, the exact roles of HOXD-AS1 in NSCLC progression are still unknown. Here, we investigated the underlying mechanisms of HOXD-AS1 in human NSCLC tissues. We found that lncRNA HOXD-AS1 was specifically upregulated (P<0.001) in NSCLC tissues and promoted cancer cell growth by targeting miR-147a. Moreover, HOXD-AS1 expression positively correlated with NSCLC clinical pathologic characteristics (tumor size, P=0.006; tumor stage, P=0.044; recurrence, P=0.031) and survival rate (P=0.003). HOXD-AS1 knockdown reduced proliferation and promoted apoptosis of NSCLC cells. The dual-luciferase reporter assay showed that HOXD-AS1 could negatively regulate the expression of miR-147a. miR-147a inhibition abrogated the effect of HOXD-AS1 knockdown on the proliferation and apoptosis of NSCLC cells. Furthermore, HOXD-AS1 positively regulated the expression of pRB (a tumor suppressor protein) in NSCLC cells. Taken together, our data indicated that HOXD-AS1 might be an oncogenic lncRNA that promotes proliferation of NSCLC and could be a therapeutic target in NSCLC.

Long non-coding RNAs associated with non-small cell lung cancer

Lung cancer, with 80–85% being non-small cell lung cancer (NSCLC), is the leading cause of cancer-related death in both men and women. Long non-coding RNAs (lncRNAs), always defined as non-protein-coding RNA molecules longer than 200 nucleotides, are now thought as a new frontier in the study of human malignant diseases including NSCLC. As researches continue, increasing number of roles that lncRNAs play in NSCLC has been found, and more and more evidences show lncRNAs have a close relationship with patients’ response to radiochemotherapy or molecular therapy. The aim of this review is to disclose the roles that lncRNAs play in NSCLC and how lncRANs influence the treatment of NSCLC.

Clinical Significance and Effect of lncRNA HOXA11-AS in NSCLC: A Study Based on Bioinformatics, In Vitro and in Vivo Verification

HOXA11 antisense RNA (HOXA11-AS) has been shown to be involved in tumorigenesis and development of different cancers. However, the role of HOXA11-AS in non-small cell lung cancer (NSCLC) remains unclear. In this study, we firstly explored and confirmed the expression of HOXA11-AS in NSCLC tissues and cells. Cytometry, CCK-8, cell scratch, migration, Matrigel invasion and flow cytometry assays were performed to determine the biological impact of HOXA11-AS in vitro. Furthermore, a chick embryo chorioallantoic membrane (CAM) model of NSCLC was constructed to explore the effect of HOXA11-AS on tumorigenicity and angiogenesis in vivo. Additionally, bioinformatics analyses were performed to investigate the prospective pathways of HOXA11-AS co-expressed genes. As results, HOXA11-AS was markedly highly expressed in NSCLC tissues and cells. Furthermore, the proliferation, migration, invasion, tumorigenic and angiogenic ability of NSCLC cells were all inhibited and apoptosis was induced after HOXA11-AS knock-down. HOXA11-AS RNAi also led to cell cycle arrest on G0/G1 or G2/M phase. In addition, the non-small cell lung cancer pathway might be involved in regulating the co-expressed genes of HOXA11-AS in NSCLC. These results indicate that HOXA11-AS plays pivotal roles in NSCLC and it can become a novel therapeutic direction for treating NSCLC.

IL-17C mediates the recruitment of tumor-associated neutrophils and lung tumor growth

Chronic obstructive pulmonary disease (COPD) is associated with an increased risk for lung cancer and an aberrant microbiota of the lung. Microbial colonization contributes to chronic neutrophilic inflammation in COPD. Nontypeable Haemophilus influenzae (NTHi) is frequently found in lungs of stable COPD patients and is the major pathogen triggering exacerbations. The epithelial cytokine interleukin-17C (IL-17C) promotes the recruitment of neutrophils into inflamed tissues. The purpose of this study was to investigate the function of IL-17C in the pulmonary tumor microenvironment. We subjected mice deficient for IL-17C (IL-17C^-/-) and mice double deficient for Toll-like receptor 2 and 4 (TLR-2/4^-/-) to a metastatic lung cancer model. Tumor proliferation and growth as well as the number of tumor-associated neutrophils was significantly decreased in IL-17C^-/- and TLR-2/4^-/- mice exposed to NTHi. The NTHi-induced pulmonary expression of IL-17C was dependent on TLR-2/4. In vitro, IL-17C increased the NTHi- and tumor necrosis factor-α-induced expression of the neutrophil chemokines keratinocyte-derived chemokine and macrophage inflammatory protein 2 in lung cancer cells but did not affect proliferation. Human lung cancer samples stained positive for IL-17C, and in non-small cell lung cancer patients with lymph node metastasis, IL-17C was identified as a negative prognostic factor. Our data indicate that epithelial IL-17C promotes neutrophilic inflammation in the tumor microenvironment and suggest that IL-17C links a pathologic microbiota, as present in COPD patients, with enhanced tumor growth.

MALAT1 in Human Adipose Stem Cells Modulates Survival and Alternative Splicing of PKCδII in HT22 Cells

Brain injury may be caused by trauma or may occur in stroke and neurodegenerative diseases. Because the central nervous system is unable to regenerate efficiently, there is utmost interest in the use of stem cells to promote neuronal survival. Of interest here are human adipose-derived stem cells (hASCs), which secrete factors that enhance regeneration and survival of neurons in sites of injury. We evaluated the effect of hASC secretome on immortalized mouse hippocampal cell line (HT22) after injury. Protein kinase C δ (PKCδ) activates survival and proliferation in neurons and is implicated in memory. We previously showed that alternatively spliced PKCδII enhances neuronal survival via B-cell lymphoma 2 Bcl2 in HT22 neuronal cells. Our results demonstrate that following injury, treatment with exosomes from the hASC secretome increases expression of PKCδII in HT22 cells and increases neuronal survival and proliferation. Specifically, we demonstrate that metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a long noncoding RNA contained in the hASC exosomes mediates PKCδII splicing, thereby increasing neuronal survival. Using antisense oligonucleotides for MALAT1 and RNA immunoprecipitation assays, we demonstrate that MALAT1 recruits splice factor serine-arginine-rich splice factor 2 (SRSF2) to promote alternative splicing of PKCδII. Finally, we evaluated the role of insulin in enhancing hASC-mediated neuronal survival and demonstrated that insulin treatment dramatically increases the association of MALAT1 and SRSF2 and substantially increases survival and proliferation after injury in HT22 cells. In conclusion, we demonstrate the mechanism of action of hASC exosomes in increasing neuronal survival. This effect of hASC exosomes to promote wound healing can be further enhanced by insulin treatment in HT22 cells.

High expression of long non-coding RNA ATB indicates a poor prognosis and regulates cell proliferation and metastasis in non-small cell lung cancer

BACKGROUND AND AIM

Long non-coding RNAs (lncRNAs) have been demonstrated to act as a critical regulator in the processes of tumor biology. In this study, whether lncRNA-ATB is a potential indicator for non-small cell lung cancer (NSCLC) was investigated and its biological function in NSCLC was also determined.

METHODS

The expression levels of lncRNA-ATB in NSCLC tissues and cell lines were measured. A549 cell line was explored to investigate the functions of lncRNA-ATB in NSCLC.

RESULTS

Real-time PCR results showed that lncRNA-ATB expression was up-regulated in both in NSCLC tissues and cell lines. High lncRNA-ATB expression in tumor tissue was associated with larger tumor size, lymph node metastasis, and distant metastasis in patients with NSCLC, respectively. In addition, the patients with high expression of lncRNA-ATB presented a lower survival probability. In vitro experiments showed that down-regulation of lncRNA-ATB promoted the cell apoptosis, whereas inhibited the cell viability, cell migration, and cell invasion.

CONCLUSION

High expression of lncRNA-ATB indicated a poor prognosis and led to the cell proliferation and metastasis in NSCLC.

Identification of long noncoding RNA expression profile in oxaliplatin-resistant hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is the most prevalent and malignant type of liver cancer. Besides the high incidence, the resistance to chemotherapy is a major problem that leads to the high mortality of HCC. Recently, aberrant expression of long noncoding RNAs (lncRNAs) has been considered as a primary feature of many types of cancer. However, the genome-wide expression pattern and associated functional implications of lncRNAs in chemo-resistant HCC cells remain unknown. In this study, we identified 120 differentially expressed lncRNAs with 61 up-regulated and 59 down-regulated (fold change>2, p<0.05) along with 421 differentially expressed mRNAs with 228 up-regulated and 193 down-regulated (fold change>2, p<0.05) in oxaliplatin-resistant (MHCC97H-OXA) HCC cells, compared to parental oxaliplatin-sensitive (MHCC97H) by microarray. The underlying pathways were related to cell death, proliferation, cellular response to stimulus, including p53 pathway, ErbB pathway and MAPK pathway. Further, 16 lncRNAs were selected for validation of microarray results with quantitative PCR, and a strong correlation was identified between the qPCR results and microarray data. We demonstrated for the first time that ENST00000438347, NR_073453 and ENST00000502804 were up-regulated in MHCC97H-OXA cells as well as chemo-resistant HCC cancerous tissues. Moreover, the expression of ENST00000518376 was significantly associated with the tumor size and differentiation. Overall survival analysis showed that high expression of ENST00000438347 and ENST00000518376 was associated with poor prognosis in HCC patients. Taken together, our results reveal that the expression profile in oxaliplatin-resistant HCC is significantly altered including lncRNAs. And a series of de novo lncRNAs play important functions in HCC oxaliplatin resistance and HCC progression.

Recent advances in epigenomics in NSCLC: real-time detection and therapeutic implications

NSCLC is an aggressive disease with one of the poorer prognosis among cancers. The disappointing response to chemotherapy drives the search for genetic biomarkers aimed at both attaining an earlier diagnosis and choosing the most appropriate chemotherapy. In this scenario, epigenomic markers, such as DNA methylation, histone acetylation and the expression of noncoding RNAs, have been demonstrated to be reliable for the stratification of NSCLC patients. Newest techniques with increased sensitivity and the isolation of nucleic acids from plasma may allow an early diagnosis and then monitoring the efficacy over time. However, prospective confirmatory studies are still lacking. This article presents an overview of the epigenetic markers evaluated in NSCLC and discusses the role of their real-time detection in the clinical management of the disease.

Functions and mechanisms of long noncoding RNAs in lung cancer

Lung cancer is a heterogeneous disease, and there is a lack of adequate biomarkers for diagnosis. Long noncoding RNAs (lncRNAs) are emerging as an important set of molecules because of their roles in various key pathophysiological pathways, including cell growth, apoptosis, and metastasis. We review the current knowledge of the lncRNAs in lung cancer. In-depth analyses of lncRNAs in lung cancer have increased the number of potential effective biomarkers, thus providing options to increase the therapeutic benefit. In this review, we summarize the functions, mechanisms, and regulatory networks of lncRNAs in lung cancer, providing a basis for further research in this field.

Clinical prognostic value of metastasis-associated lung adenocarcinoma transcript 1 in various human cancers: an updated meta-analysis

BACKGROUND

Many studies have investigated the prognostic value of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in human cancers. However, these studies were often limited by small sample sizes. Therefore, we performed this updated meta-analysis to summarize the potential value of MALAT1 as a biomarker for early treatment and to predict survival in various human malignant neoplasms, through the inclusion of the latest literature and improved methodology.

METHODS

Twelve eligible articles were systematically obtained from PubMed, Medline, Embase, Web of Science, China National Knowledge Infrastructure and the Cochrane Library, from inception up to June 30, 2015. Survival was assessed using pooled hazard ratios (HRs) and 95% confidence intervals (95% CIs).

RESULTS

By combining the results of 12 studies, we found elevated MALAT1 expression was associated with poor survival in most cancers, with a pooled HR of 1.90 (95% CI, 1.56-2.30) for overall survival (OS) and 3.06 (95% CI, 2.06-4.56) for recurrence-free survival/disease-free survival. Subgroup analyses according to ethnicity, tumor type, assay method, sample size, HR-calculation method and analysis type did not affect the predictive role of MALAT1 for OS in various cancer types. Further, by combining results from studies that used multivariate analyses, we found elevated MALAT1 was an independent prognostic factor for OS (HR = 1.98; 95% CI, 1.58-2.48).

CONCLUSIONS

MALAT1 could serve as a potential prognostic biomarker in various cancers and may be a potential therapeutic target for the treatment and early detection of recurrence.

The Long Noncoding RNA MALAT-1 is A Novel Biomarker in Various Cancers: A Meta-analysis Based on the GEO Database and Literature

Background: MALAT-1 is significantly overexpressed in various cancers, suggesting that it might be a potential biomarker of cancer.

Methods: A meta-analysis was performed using microarray data obtained via the Affymetrix Human Genome U133 Plus 2.0 platform found in the Gene Expression Omnibus (GEO) database and data obtained through a systematic search of PubMed and Web of Science. The pooled odds ratio (OR) and hazard ratio (HR) with 95% CI (Confidence interval) were used to judge the value of biomarkers.

Results: A total of 28 studies were included in this meta-analysis, comprising a total of 3573 patients. MALAT-1 was significantly linked with over survival (OS) (HR=1.58, 95%CI: 1.12-2.23), recurrence-free survival (RFS) (HR=2.32, 95% CI: 1.68-3.19) and death-free survival (DFS) (HR=3.28, 95% CI: 1.52-7.09). We found that MALAT-1 was a risk factor in the prognoses of lung cancer (HR=1.54, 95%CI: 1.01-2.34), digestive system cancer (HR=2.16, 95% CI: 1.34-3.48) and ovarian cancer (HR=3.98, 95% CI: 1.54-10.25). In contrast, MALAT-1 was a safe factor in the prognosis of B cell lineage cancer (HR=0.45, 95% CI: 0.33-0.61). MALAT-1 was also a risk factor of RFS in breast cancer (HR=1.97, 95% CI: 1.25-3.09) and the TNM stage in pancreatic cancer (OR=3.65, 95% CI: 1.86-7.18) and glioma (OR=4.30, 95% CI: 1.90-9.73) and was a safe factor in colorectal cancer (OR=0.17, 95% CI: 0.08-0.35). MALAT-1 was significantly associated with lymph node metastasis in clear cell carcinoma (OR=5.04, 95% CI: 2.36-10.78) and distant metastasis in pancreatic cancer (OR=11.64, 95% CI: 2.13-63.78).

Conclusions: MALAT-1 can serve as a molecular marker in different types of cancers.

Prognostic value of Bcl-2 expression in patients with non-small-cell lung cancer: a meta-analysis and systemic review

Objective

B-cell-lymphoma-2 (Bcl-2) is a proto-oncogene that plays an important role in the regulation of apoptosis and cell survival. However, there are much conflicting data in the literature concerning the association between Bcl-2 and prognosis in non-small-cell lung cancer (NSCLC). There is little in the way of meta-analysis focused on Bcl-2 and its effect on NSCLC prognosis. This study was performed to provide an assessment of whether expression levels of Bcl-2 are associated with prognosis in patients with NSCLC.

Materials and methods

We searched PubMed, the Cochrane Library, and China National Knowledge Infrastructure for all eligible studies. The combined hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) in terms of overall survival were evaluated.

Results

Fifty published studies including 6,863 patients with lung cancer were included in this meta-analysis. Overall, Bcl-2 was expressed in 33% of the NSCLC tumors studied. Our analysis indicates that NSCLC patients with Bcl-2-positive expression have a better prognosis than those with Bcl-2-negative expression in both Asian and non-Asian study populations (HR 0.79, 95% CI 0.72–0.87, P<0.00001). However, Bcl-2-positive expression seems to have no significant impact on survival of stage I NSCLC patients.

Conclusion

Our results indicated that Bcl-2 might be a useful prognostic marker for NSCLC generally. Larger clinical trials are needed to confirm the prognostic value of Bcl-2 in stage I NSCLC.

Epigenetic silencing of p21 by long non-coding RNA HOTAIR is involved in the cell cycle disorder induced by cigarette smoke extract

Long noncoding RNAs (lncRNAs), which are epigenetic regulators, are involved in human malignancies. Little is known, however, about the molecular mechanisms for lncRNA regulation of genes induced by cigarette smoke. We recently found that, in human bronchial epithelial (HBE) cells, the lncRNA, Hox transcript antisense intergenic RNA (HOTAIR), is associated with changes in the cell cycle caused by cigarette smoke extract (CSE). In the present study, we report that increased expression of HOTAIR and enhancer of zeste homolog 2 (EZH2), and tri-methylation of Lys 27 of histone H3 (H3K27me3), affect cell cycle progression during CSE-induced transformation of HBE cells. Inhibition of HOTAIR and EZH2 by siRNAs attenuated CSE-induced decreases of p21 levels. Further, ChIP assays verified that HOTAIR and EZH2 were needed to maintain the interaction of H3K27me3 with the promoter regions of p21; combined use of a HOTAIR plasmid and EZH2 siRNA supported this observation. Thus, HOTAIR epigenetic silencing of p21 via EZH2-mediated H3K27 trimethylation contributes to changes in the cell cycle induced by CSE. These observations provide further understanding of the regulation of CSE-induced lung carcinogenesis and identify new therapeutic targets.

PD-1 and PD-L1 Expression in NSCLC Indicate a Favorable Prognosis in Defined Subgroups

Background

Immunotherapy can become a crucial therapeutic option to improve prognosis for lung cancer patients. First clinical trials with therapies targeting the programmed cell death receptor PD-1 and its ligand PD-L1 have shown promising results in several solid tumors. However, in lung cancer the diagnostic, prognostic and predictive value of these immunologic factors remains unclear.

Method

The impact of both factors was evaluated in a study collective of 321 clinically well-annotated patients with non-small lung cancer (NSCLC) using immunohistochemistry.

Results

PD-1 expression by tumor infiltrating lymphocytes (TILs) was found in 22%, whereas tumor cell associated PD-L1 expression was observed in 24% of the NSCLC tumors. In Fisher’s exact test a positive correlation was found for PD-L1 and Bcl-xl protein expression (p = 0.013). Interestingly, PD-L1 expression on tumor cells was associated with improved overall survival in pulmonary squamous cell carcinomas (SCC, p = 0.042, log rank test), with adjuvant therapy (p = 0.017), with increased tumor size (pT2-4, p = 0.039) and with positive lymph node status (pN1-3, p = 0.010). These observations were confirmed by multivariate cox regression models.

Conclusion

One major finding of our study is the identification of a prognostic implication of PD-L1 in subsets of NSCLC patients with pulmonary SCC, with increased tumor size, with a positive lymph node status and NSCLC patients who received adjuvant therapies. This study provides first data for immune-context related risk stratification of NSCLC patients. Further studies are necessary both to confirm this observation and to evaluate the predictive value of PD-1 and PD-L1 in NSCLC in the context of PD-1 inhibition.

PD-1 and PD-L1 Expression in NSCLC Indicate a Favorable Prognosis in Defined Subgroups

BACKGROUND

Immunotherapy can become a crucial therapeutic option to improve prognosis for lung cancer patients. First clinical trials with therapies targeting the programmed cell death receptor PD-1 and its ligand PD-L1 have shown promising results in several solid tumors. However, in lung cancer the diagnostic, prognostic and predictive value of these immunologic factors remains unclear.

METHOD

The impact of both factors was evaluated in a study collective of 321 clinically well-annotated patients with non-small lung cancer (NSCLC) using immunohistochemistry.

RESULTS

PD-1 expression by tumor infiltrating lymphocytes (TILs) was found in 22%, whereas tumor cell associated PD-L1 expression was observed in 24% of the NSCLC tumors. In Fisher's exact test a positive correlation was found for PD-L1 and Bcl-xl protein expression (p = 0.013). Interestingly, PD-L1 expression on tumor cells was associated with improved overall survival in pulmonary squamous cell carcinomas (SCC, p = 0.042, log rank test), with adjuvant therapy (p = 0.017), with increased tumor size (pT2-4, p = 0.039) and with positive lymph node status (pN1-3, p = 0.010). These observations were confirmed by multivariate cox regression models.

CONCLUSION

One major finding of our study is the identification of a prognostic implication of PD-L1 in subsets of NSCLC patients with pulmonary SCC, with increased tumor size, with a positive lymph node status and NSCLC patients who received adjuvant therapies. This study provides first data for immune-context related risk stratification of NSCLC patients. Further studies are necessary both to confirm this observation and to evaluate the predictive value of PD-1 and PD-L1 in NSCLC in the context of PD-1 inhibition.