LncRNA DICER1-AS1 promotes the proliferation, invasion and autophagy of osteosarcoma cells via miR-30b/ATG5

Osteosarcoma in a ceRNET perspective

Osteosarcoma (OS) is the most prevalent and fatal type of bone tumor. It is characterized by great heterogeneity of genomic aberrations, mutated genes, and cell types contribution, making therapy and patients management particularly challenging. A unifying picture of molecular mechanisms underlying the disease could help to transform those challenges into opportunities.This review deeply explores the occurrence in OS of large-scale RNA regulatory networks, denominated "competing endogenous RNA network" (ceRNET), wherein different RNA biotypes, such as long non-coding RNAs, circular RNAs and mRNAs can functionally interact each other by competitively binding to shared microRNAs. Here, we discuss how the unbalancing of any network component can derail the entire circuit, driving OS onset and progression by impacting on cell proliferation, migration, invasion, tumor growth and metastasis, and even chemotherapeutic resistance, as distilled from many studies. Intriguingly, the aberrant expression of the networks components in OS cells can be triggered also by the surroundings, through cytokines and vesicles, with their bioactive cargo of proteins and non-coding RNAs, highlighting the relevance of tumor microenvironment. A comprehensive picture of RNA regulatory networks underlying OS could pave the way for the development of innovative RNA-targeted and RNA-based therapies and new diagnostic tools, also in the perspective of precision oncology.

Knockdown of LncRNA DICER1-AS1 arrests the cell cycle, inhibits cell proliferation, and induces cell apoptosis by regulating CDC5L nuclear transfer in osteosarcoma

BACKGROUND

DICER1-AS1 is reported to promote the progression and disturb the cell cycle in osteosarcoma; however, its mechanism has rarely been studied.

MATERIALS AND METHODS

DICER1-AS1 expression levels were evaluated by qPCR and fluorescence in situ hybridization (FISH). The total, nuclear, and cytosolic levels of CDC5L were measured by western blotting and immunofluorescence (IF). Cell proliferation, apoptosis, and cell cycle analyses were conducted using the colony formation, CCK-8 assay, terminal transferase-mediated UTP nick end-labeling kit (TUNEL) assay, and flow cytometry. Levels of cell proliferation-, cell cycle-, and cell apoptosis-related proteins were determined by western blotting. RNA immunoprecipitation (RIP) and RNA pull-down assays were conducted to evaluate the relationship between DICER1-AS1 and CDC5L.

RESULTS

LncRNA DICER1-AS1 was highly expressed in samples of osteosarcoma tissue and in osteosarcoma cell lines. DICER1-AS1 knockdown inhibited cell proliferation, promoted cell apoptosis, and disturbed the cell cycle. Moreover, DICER1-AS1 was found to bind with CDC5L, and knockdown of DICER-AS1 inhibited the nuclear transfer of CDC5L. DICER1-AS1 knockdown also reversed the effects of CDC5L overexpression on cell proliferation, apoptosis, and the cell cycle. Moreover, CDC5L inhibition suppressed cell proliferation, promoted cell apoptosis, and disturbed the cell cycle, and those effects were further enhanced by DICER1-AS1 knockdown. Finally, DICER1-AS knockdown inhibited tumor growth and proliferation, and promoted cell apoptosis in vivo.

CONCLUSION

LncRNA DICER1-AS1 knockdown inhibits the nuclear transfer of CDC5L protein, arrests the cell cycle, and induces apoptosis to suppress the development of osteosarcoma. Our results suggest a novel target (DICER1-AS1) for treatment of osteosarcoma.

Deregulation of NF-κB associated long non-coding RNAs in bipolar disorder

Long non-coding RNAs (lncRNAs) are major genetic factors whose disruption lead to many diseases, including nervous system diseases. Bipolar disorder (BD) is a neuro-psychiatric disease with no definitive diagnosis and incomplete treatment. Regarding the role of NF-κB-associated lncRNAs in the neuro-psychiatric disorders, we examined the expression of three lncRNAs, DICER1-AS1, DILC, and CHAST, in BD patients. To assess lncRNA expression in peripheral blood mononuclear cells (PBMCs) of 50 BD patients and 50 healthy individuals, Real-time PCR was used. Additionally, some clinical characteristics of BD patients were investigated via an analysis of ROC curves and correlations. Based on our results, the expression level of CHAST increased significantly in BD patients in comparison with healthy people, in BD men compared with healthy men, as well as in BD women in comparison with control females (p < 0.05). A similar increase in expression was observed for DILC and DICER1-AS1 lncRNAs in female patients compared with healthy women. Whereas compared to healthy men, DILC was decreased in diseased men. Based on the results of the ROC curve, the area under the curve (AUC) for CHAST lncRNA was 0.83 with a P value of 0.0001. So, the expression level of CHAST lncRNA could play a role in the pathobiology of the BD and be considered a good putative biomarker for individuals with bipolar disorder.

Autophagy Modulation as a Potential Therapeutic Strategy in Osteosarcoma: Current Insights and Future Perspectives

Autophagy, the process that enables the recycling and degradation of cellular components, is essential for homeostasis, which occurs in response to various types of stress. Autophagy plays an important role in the genesis and evolution of osteosarcoma (OS). The conventional treatment of OS has limitations and is not always effective at controlling the disease. Therefore, numerous researchers have analyzed how controlling autophagy could be used as a treatment or strategy to reverse resistance to therapy in OS. They highlight how the inhibition of autophagy improves the efficacy of chemotherapeutic treatments and how the promotion of autophagy could prove positive in OS therapy. The modulation of autophagy can also be directed against OS stem cells, improving treatment efficacy and preventing cancer recurrence. Despite promising findings, future studies are needed to elucidate the molecular mechanisms of autophagy and its relationship to OS, as well as the mechanisms underlying the functioning of autophagic modulators. Careful evaluation is required as autophagy modulation may have adverse effects on normal cells, and the optimization of autophagic modulators for use as drugs in OS is imperative.

Unravelling the complexity of lncRNAs in autophagy to improve potential cancer therapy

Autophagy is well-known as an internal catabolic process that is evolutionarily conserved and performs the key biological function in maintaining cellular homeostasis. It is tightly controlled by several autophagy-related (ATG) proteins, which are closely associated with many types of human cancers. However, what has remained controversial is the janus roles of autophagy in cancer progression. Interestingly, the biological function of long non-coding RNAs (lncRNAs) in autophagy has been gradually understood in different types of human cancers. More recently, numerous studies have demonstrated that several lncRNAs may regulate some ATG proteins and autophagy-related signaling pathways to either activate or inhibit the autophagic process in cancer. Thus, in this review, we summarize the latest advance in the knowledge of the complicated relationships between lncRNAs and autophagy in cancer. Also, the in-depth dissection of the lncRNAs-autophagy-cancers axis involved in this review would shed new light on discovery of more potential cancer biomarkers and therapeutic targets in the future.

Targeting Autophagy Using Long Non-Coding RNAs (LncRNAs): New Landscapes in the Arena of Cancer Therapeutics

Cancer has become a global health hazard accounting for 10 million deaths in the year 2020. Although different treatment approaches have increased patient overall survival, treatment for advanced stages still suffers from poor clinical outcomes. The ever-increasing prevalence of cancer has led to a reanalysis of cellular and molecular events in the hope to identify and develop a cure for this multigenic disease. Autophagy, an evolutionary conserved catabolic process, eliminates protein aggregates and damaged organelles to maintain cellular homeostasis. Accumulating evidence has implicated the deregulation of autophagic pathways to be associated with various hallmarks of cancer. Autophagy exhibits both tumor-promoting and suppressive effects based on the tumor stage and grades. Majorly, it maintains the cancer microenvironment homeostasis by promoting viability and nutrient recycling under hypoxic and nutrient-deprived conditions. Recent investigations have discovered long non-coding RNAs (lncRNAs) as master regulators of autophagic gene expression. lncRNAs, by sequestering autophagy-related microRNAs, have been known to modulate various hallmarks of cancer, such as survival, proliferation, EMT, migration, invasion, angiogenesis, and metastasis. This review delineates the mechanistic role of various lncRNAs involved in modulating autophagy and their related proteins in different cancers.

LncRNA DICER1-AS1 promotes colorectal cancer progression by activating the MAPK/ERK signaling pathway through sponging miR-650

BACKGROUND

Colorectal cancer (CRC) is a disease with high morbidity and mortality rates globally. Long noncoding RNAs (lncRNAs) play a fundamental role in tumor progression, and increasing attention has been paid to their role in CRC. This study aimed to determine the function of lncRNA DICER1 antisense RNA 1 (DICER1-AS1) in CRC and confirm its potential regulatory mechanisms in CRC.

METHODS

The publicly available dataset was used to assess DICER1-AS1 function and expression in CRC. RT-qPCR or western blot assays were performed to verify DICER1-AS1, miR-650, and mitogen-activated protein kinase 1 (MAPK1) expression in CRC cells or tissues. To determine the function of DICER1-AS1, we performed CCK-8, colony formation, transwell, cell cycle, and in vivo animal assays. Using RNA sequence analysis, luciferase reporter assays, and bioinformatics analysis, the connection between DICER1-AS1, MAPK1, and miR-650 was investigated.

RESULTS

DICER1-AS1 was significantly upregulated in CRC tissue compared to normal colon tissue. High DICER1-AS1 expression suggested a poor prognosis in CRC patients. Functionally, upregulation of DICER1-AS1 effectively promoted CRC proliferation, migration, and invasion ex vivo and tumor progression in vivo. Mechanistically, DICER1-AS1 functions as a competitive endogenous RNA (ceRNA) that sponges miR-650 to upregulate MAPK1, promotes ERK1/2 phosphorylation, and sequentially activates the MAPK/ERK signaling pathway.

CONCLUSION

Our investigations found that upregulation of DICER1-AS1 activates the MAPK/ERK signaling pathway by sponging miR-650 to promote CRC progression, revealing a possible clinically significant biomarker and therapeutic target.

DARS-AS1 recruits METTL3/METTL14 to bind and enhance DARS mRNA m6A modification and translation for cytoprotective autophagy in cervical cancer

Cervical cancer (CC) is one of the most prevalent malignancies among females. Cytoprotective autophagy could confer cancer cell tolerance to hypoxic stress, promoting cell survival and adaptation. Aspartyl-tRNA synthetase 1 antisense 1 (DARS-AS1) is an oncogenic long non-coding RNA (lncRNA) in various cancers, but how DARS-AS1 regulates cytoprotective autophagy in hypoxic environment in CC remains unclear. Chromatin immunoprecipitation (ChIP) and luciferase reporter assays were conducted to explore the interaction between hypoxia-inducible factor 1 subunit alpha (HIF1α) and DARS-AS1 promoter. Methylated RNA immunoprecipitation (MeRIP) followed by quantitative real-time polymerase-chain reaction (RT-qPCR) detected methylated RNA level. The process of autophagic maturation was monitored by immunofluorescence staining. Higher DARS-AS1 expression was found in CC tissues and cytoprotective. We also uncovered that hypoxic exposure induced cytoprotective autophagy via HIF1α/DARS-AS1/DARS axis. Moreover, DARS-AS1 was validated to facilitate DARS translation via recruiting N6-adenosine-methyltransferase methyltransferase like 3 (METTL3) and methyltransferase like 14 (METTL14), which bound with DARS mRNA DARS mRNA 5’ untranslated region (5ʹUTR) and promoting its translation. The present study demonstrated that the ‘HIF1α/DARS-AS1/DARS/ATG5/ATG3’ pathway regulated the hypoxia-induced cytoprotective autophagy of CC and might be a promising target of therapeutic strategies for patients afflicted with CC.

Exploring the role of non-coding RNAs in autophagy

As a self-degradative mechanism, macroautophagy/autophagy has a role in the maintenance of energy homeostasis during critical periods in the development of cells. It also controls cellular damage through the eradication of damaged proteins and organelles. This process is accomplished by tens of ATG (autophagy-related) proteins. Recent studies have shown the involvement of non-coding RNAs in the regulation of autophagy. These transcripts mostly modulate the expression of ATG genes. Both long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been shown to modulate the autophagy mechanism. Levels of several lncRNAs and miRNAs are altered in this process. In the present review, we discuss the role of lncRNAs and miRNAs in the regulation of autophagy in diverse contexts such as cancer, deep vein thrombosis, spinal cord injury, diabetes and its complications, acute myocardial infarction, osteoarthritis, pre-eclampsia and epilepsy.Abbreviations: AMI: acute myocardial infarction; ATG: autophagy-related; lncRNA: long non-coding RNA; miRNA: microRNA.

Regulation of miR-30b in cancer development, apoptosis, and drug resistance

miR-30b, which is encoded by the gene located on chromosome 8q24.22, plays an important role in a variety of diseases. In most types of tumors, miR-30b significantly inhibits the proliferation, migration, and invasion of cancer cells through the regulation of target genes. Moreover, miR-30b can inhibit the PI3K/AKT signaling pathway through the regulation of EGFR, AKT, Derlin-1, GNA13, SIX1, and other target genes, thus inhibiting the EMT process of tumor cells and promoting apoptosis. In addition, miR-30 plays a significant role in alleviating drug resistance in tumor cells. Although the use of miR-30b as a clinical diagnostic indicator or anticancer drug is still facing great difficulties in the short term, with the deepening of research, the potential application of miR-30b is emerging.

A reciprocal feedback between N6-methyladenosine reader YTHDF3 and lncRNA DICER1-AS1 promotes glycolysis of pancreatic cancer through inhibiting maturation of miR-5586-5p

Background

Glycolysis is a pivotal process in metabolic reprogramming of tumorigenesis. Previous research has indicated that lncRNAs might play crucial roles in glycolysis of various tumors. However, the function of lncRNAs in glycolysis of pancreatic cancer has not been fully elucidated.

Methods

Bio-information analyses were applied to reveal the potential glycolysis-associated lncRNA. RT-PCR and fluorescence in situ hybridization (FISH) assays were applied to detect the expression of antisense RNA1 of DICER1 (DICER1-AS1) in pancreatic cancer tissues and cell lines. Gain- and loss-of-function experiments were performed to evaluate the roles of DICER1-AS1 in glycolysis and tumorigenesis of PC. Mechanistic experiments including luciferase reporter assay, RNA immunoprecipitation (RIP), and chromatin immunoprecipitation (ChIP) were employed to uncover the downstream targets and regulatory mechanism of DICER1-AS1 in glycolysis of PC.

Results

Bio-information analysis indicated that DICER1-AS1 was downregulated in PC and negatively correlated with glycolytic genes expression. Meanwhile, overexpression of DICER1-AS1 inhibited glycolysis, proliferation, and metastasis of PC cells both in vitro and in vivo. Mechanistically, DICER1-AS1 promoted transcription of its sense gene DICER1 by recruiting transcriptional factor YY1 to the DICER1 promoter. Meanwhile, DICER1 promoted maturation of miR-5586-5p which consequently inhibited glycolytic gene expression including LDHA, HK2, PGK1, and SLC2A1. Notably, enhanced interaction between N6-methyladenosine (m6A) reader YTHDF3 and DICER1-AS1 led to degradation of DICER1-AS1 in response to glucose depletion. Moreover, our data revealed that YTHDF3 was a critical target for miR-5586-5p, by which forming a negative feedback with DICER1-AS1 to regulate glycolysis of PC.

Conclusion

Our results implicate a negative feedback of m6A reader YTHDF3 and glycolytic lncRNA DICER1-AS1 is involved in glycolysis and tumorigenesis of PC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-022-02285-6.

Knockdown of lncRNA LINC00662 suppresses malignant behaviour of osteosarcoma cells via competition with miR-30b-3p to regulate ELK1 expression

Purpose

Osteosarcoma is a type of bone malignancy that mainly occurred in teenagers. This investigation is aimed to clarify the effect of long non-coding RNA (lncRNA) LINC00662 on the proliferation, migration, and invasion in osteosarcoma and explore the underlying action mechanisms.

Methods

The mRNA expression of LINC00662 was determined by real-time quantitative polymerase chain reaction. Cell proliferation, migration, and invasion were evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, wound healing, and transwell assays, respectively. A dual-luciferase reporter assay was used to validate the target relationships Between microRNA (miR)-30b-3p and LINC00662/ ETS domain-containing protein 1 (ELK1). Western blotting was performed to determine the protein expression of ELK1. Xenograft model was established to evaluate the effects of LINC00662 silencing on tumor growth in vivo.

Results

LncRNA LINC00662 and ELK1 were significantly increased, while miR-30b-3p was reduced in osteosarcoma tissues. The results of functional experiments indicated that transfection of small hairpin (sh)-LINC00662 and miR-30b-3p mimics repressed the migration, invasion, and proliferation of osteosarcoma cells. LncRNA LINC00662 also appeared to sponge miR-30b-3p in order to affect the expression of ELK1. Simultaneously, there were weak negative correlations between the expression of miR-30b-3p and LINC00662/ELK1 in osteosarcoma tissues. Rescue experiments suggested that ELK1 overexpression and downregulation of miR-30b-3p reversed the suppressive effects of sh-LINC00662 on the cell migration, invasion, and proliferation in osteosarcoma.

Conclusions

The current study indicated that knockdown of LINC00662 repressed cell migration, invasion, and proliferation through sponging miR-30b-3p to regulate the expression of ELK1 in osteosarcoma. These results may uncover a promising target for the treatment of osteosarcoma.

SNHG1 functions as an oncogenic lncRNA and promotes osteosarcoma progression by up-regulating S100A6 via miR-493-5p

The mechanism behind the aberrant expression of S100A6 in osteosarcoma is seldom reported so far. This study sought to explore the regulatory axis targeting S100A6 involved in osteosarcoma progression. Clinical samples collected from osteosarcoma patients were used to detect the expressions of SNHG1, miR-493-5p, and S100A6 by western bolt analysis and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The effects of S100A6 on proliferation and osteogenic differentiation were investigated by the CCK-8 assay, colony formation assay, Ethynyl deoxyuridine staining, matrix mineralization assay, and alkaline phosphatase assay. The potential of lncRNAs/miRNAs targeting S100A6 was identified by the bioinformatics approach, and the results were verified by the dual luciferase assay and RNA immunoprecipitation assay. Both and rescue experiments were performed to investigate the regulatory relationship between the identified lncRNAs and S100A6. The results showed that S100A6 is highly expressed in osteosarcoma. S100A6 overexpression not only increases the proliferation but also reduces the osteogenic differentiation of osteosarcoma cells, while S1006A silence exerts the opposite effects. Then, SNHG1 is identified to directly interact with miR-493-5p to attenuate miR-493-5p binding to the 3'-untranslated region of S100A6. Notably, S100A6 silence partially rescues the effect of SNHG1 overexpression on proliferation and osteogenic differentiation of osteosarcoma cells. Furthermore, the suppressive role of SNHG1 silence in the growth of osteosarcoma xenograft tumors is countered by S100A6 overexpression. Collectively, this study reveals that S100A6 plays an important role in osteosarcoma progression, and SNHG1 promotes S100A6 expression by competitively sponging miR-493-5p.

Sestrin2-Mediated Autophagy Contributes to Drug Resistance via Endoplasmic Reticulum Stress in Human Osteosarcoma

One contributor to the high mortality of osteosarcoma is its reduced sensitivity to chemotherapy, but the mechanism involved is unclear. Improving the sensitivity of osteosarcoma to chemotherapy is urgently needed to improve patient survival. We found that chemotherapy triggered apoptosis of human osteosarcoma cells in vitro and in vivo; this was accompanied by increased Sestrin2 expression. Importantly, autophagy was also enhanced with increased Sestrin2 expression. Based on this observation, we explored the potential role of Sestrin2 in autophagy of osteosarcoma. We found that Sestrin2 inhibited osteosarcoma cell apoptosis by promoting autophagy via inhibition of endoplasmic reticulum stress, and this process is closely related to the PERK-eIF2α-CHOP pathway. In addition, our study showed that low Sestrin2 expression can effectively reduce autophagy of human osteosarcoma cells after chemotherapy, increase p-mTOR expression, decrease Bcl-2 expression, promote osteosarcoma cell apoptosis, and slow down tumour progression in NU/NU mice. Sestrin2 activates autophagy by inhibiting mTOR via the PERK-eIF2α-CHOP pathway and inhibits apoptosis via Bcl-2. Therefore, our results explain one underlying mechanism of increasing the sensitivity of osteosarcoma to chemotherapy and suggest that Sestrin2 is a promising gene target.

A Novel Inflammatory lncRNAs Prognostic Signature for Predicting the Prognosis of Low-Grade Glioma Patients

Background

As immunotherapy has received attention as new treatments for brain cancer, the role of inflammation in the process of glioma is of particular importance. Increasing studies have further shown that long non-coding RNAs (lncRNAs) are important factors that promote the development of glioma. However, the relationship between inflammation-related lncRNAs and the prognosis of glioma patients remains unclear. The purpose of this study is to construct and validate an inflammation-related lncRNA prognostic signature to predict the prognosis of low-grade glioma patients.

Methods

By downloading and analyzing the gene expression data and clinical information of the Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) patients with low-grade gliomas, we could screen for inflammatory gene-related lncRNAs. Furthermore, through Cox and the Least Absolute Shrinkage and Selection Operator regression analyses, we established a risk model and divided patients into high- and low-risk groups based on the median value of the risk score to analyze the prognosis. In addition, we analyzed the tumor mutation burden (TMB) between the two groups based on somatic mutation data, and explored the difference in copy number variations (CNVs) based on the GISTIC algorithm. Finally, we used the MCPCounter algorithm to study the relationship between the risk model and immune cell infiltration, and used gene set enrichment analysis (GSEA), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses to explore the enrichment pathways and biological processes of differentially expressed genes between the high- and low-risk groups.

Results

A novel prognostic signature was constructed including 11 inflammatory lncRNAs. This risk model could be an independent prognostic predictor. The patients in the high-risk group had a poor prognosis. There were significant differences in TMB and CNVs for patients in the high- and low-risk groups. In the high-risk group, the immune system was activated more significantly, and the expression of immune checkpoint-related genes was also higher. The GSEA, GO, and KEGG analyses showed that highly expressed genes in the high-risk group were enriched in immune-related processes, while lowly expressed genes were enriched in neuromodulation processes.

Conclusion

The risk model of 11 inflammation-related lncRNAs can serve as a promising prognostic biomarker for low-grade gliomas patients.

Long Noncoding RNA DICER1-AS1 Functions in Methylation Regulation on the Multi-Drugresistance of Osteosarcoma Cells via miR-34a-5p and GADD45A

Osteosarcoma (OS) is a common malignant bone tumor that commonly occurs in children and adolescents. Long noncoding RNAs (lncRNAs) are recognized as a novel class of regulators of gene expression associated with tumorigenesis. However, the effect and mechanism of lncRNAs in OS tumorigenesis and drug resistance have not been characterized. The purpose of the study is to screen potential biomarker and therapeutic target against OS. We compared the lncRNA expression profiles between OS cell lines with different drug resistance levels using RNA-seq analysis and found that lncRNA DICER1-AS1 was significantly differentially expressed in multi-drugresistant OS cells SJSA-1 versus multi-drugsensitive OS cells G-292. Bisulfite Sequencing PCR (BSP) assay was performed to analyze the differential methylation status of the promoter region of DICER1-AS1 in four OS cells. Subsequently, in vitro gain- and loss-of-function experiments demonstrated the roles of DICER1-AS1 and miR-34a-5p in the multi-drugresistance of OS cells. The main findings is that DICER1-AS1 directly binds to miR-34a-5p, and their expression has a negative correlation with each other. The hypermethylation of the promoter region of DICER1-AS1 silenced its expression in the drugresistant cells SJSA-1 and MNNG/HOS. Moreover, we found that growth arrest and DNA damage-inducible alpha (GADD45A) participates in the DICER1-AS1/miR-34a-5p-regulated drug resistance of OS cells, probably via the cell cycle/pRb-E2F pathway. Our results revealed DICER1-AS1/miR-34a-5p-regulated drug resistance of OS cells, a new lncRNA-regulated network in OS tumorigenesis, suggested that DICER1-AS1 can be considered as a potential biomarker and therapeutic target against OS cells.

Apelin/APJ signaling activates autophagy to promote human lung adenocarcinoma cell migration

AIMS

Beclin1(BECN1) is known as an autophagy-related protein and the expression is promoted by apelin in lung adenocarcinoma cells, suggesting that apelin activates autophagy in lung adenocarcinoma. However, the functions of apelin-induced autophagy in lung adenocarcinoma tumorigenesis and deterioration are still unknown. Thus, this study aims to investigate the effects of apelin-induced autophagy on lung adenocarcinoma tumorigenesis and deterioration.

MAIN METHODS

Protein expression of exogenous genes were detected by Western blotting analysis. Lung adenocarcinoma cell migration was assessed with cell migration assays. Autophagy was measured with quantification of GFP-LC3 or RFP-GFP-LC3 puncta using fluorescence microscopy in cells by an observed blinded to experimental condition and by western blot analysis of LC3 and p62 in cell lysates as well as autophagy flux. Immunofluorescence staining was performed in human lung adenocarcinoma A549 cells with p-cofilin antibody. The proteins expression in cancer specimens were examined with immunohistochemistry.

KEY FINDINGS

Here, we reveal that apelin induces autophagy activation in lung adenocarcinoma. Apelin/APJ regulates BECN1 transcription via HIF1A. Apelin/APJ-activated autophagy promotes lung adenocarcinoma cell migration. Moreover, treatment with autophagy inhibitors significantly decreases apelin/APJ-induced lung adenocarcinoma cell migration. Evaluation of patient samples of lung adenocarcinoma reveals an association between APJ with BECN1 expression and a poor prognosis.

SIGNIFICANCE

Our studies demonstrate that apelin-induced autophagy promotes lung adenocarcinoma cell migration which suggests a potential therapeutic target for lung adenocarcinoma.

Silencing of the Long Non-Coding RNA TTN-AS1 Attenuates the Malignant Progression of Osteosarcoma Cells by Regulating the miR-16-1-3p/TFAP4 Axis

Objectives

Osteosarcoma (OS) is a type of bone malignancy. This study attempted to explore the effect of long non-coding RNA TTN-AS1 (TTN-AS1) on OS and to determine its molecular mechanisms.

Methods

The expression of TTN-AS1, microRNA-16-1-3p (miR-16-1-3p), and transcription factor activating enhancer binding protein 4 (TFAP4) in OS was assessed using qRT-PCR. The OS cell proliferation, migration, and invasion were measured using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), wound-healing, and transwell assays. N-cadherin and MMP-2 protein level was determined with western blot. Interactions between TTN-AS1 and miR-16-1-3p or TFAP4 and miR-16-1-3p were confirmed using the dual-luciferase reporter assay. Additionally, an OS xenograft tumor model was constructed to assess the effect of TTN-AS1 on tumor growth.

Results

TTN-AS1 and TFAP4 expression was increased in OS, while miR-16-1-3p expression was decreased. TTN-AS1 silencing restrained OS cell proliferation, migration, invasion, N-cadherin and MMP-2 protein expression, and hindered tumor growth. MiR-16-1-3p overexpression retarded the malignant behavior of OS cells. TTN-AS1 played a carcinostatic role by down-regulating miR-16-1-3p in the OS cells. Moreover, miR-16-1-3p inhibition or TFAP4 elevation weakened the suppressive effect of TTN-AS1 silencing on OS cell tumor progression.

Conclusion

TTN-AS1 promoted the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of OS cells via mediating the miR-16-1-3p/TFAP4 axis. TTN-AS1 may be a critical target for improving OS.

LncRNA-NNT-AS1 contributes to the progression of glioma by miR-582-5p/EZH2 axis

Increasing studies have shown that long non-coding RNAs (lncRNAs) had crucial regulatory roles in many diseases. Nevertheless, the biological relevance and mechanisms of the NNT-AS1 in gliom remain poorly understood. In the present study, NNT-AS1 expression was up-regulated in the glioma cell lines. Functional assays demonstrated that depletion of NNT-AS1 could notably suppress the proliferation, migration, invasion and EMT of U87MG and A172 cells. In addition, miR-582-5p was predicted to be a target of NNT-AS1 and EZH2 was predicted to be a target of miR-582-5p by bioinformatics software, which was further confirmed by luciferase reporter assay. Additionally, results of recue assays proofed that NNT-AS1/miR-582-5p/EZH2 axis aggravated the malignant behaviors of glioma. Ultimately, our findings revealed that NNT-AS1 contributes to progression via targeting miR-582-5p/EZH2 axis, revealing NNT-AS1 as a latent effective target for the diagnosis and treatment of glioma patients.

Identification and Validation of an Autophagy-Related lncRNA Signature for Patients With Breast Cancer

Background

Autophagy is a “self-feeding” phenomenon of cells, which is crucial in mammalian development. Long non-coding RNA (lncRNA) is a new regulatory factor for cell autophagy, which can regulate the process of autophagy to affect tumor progression. However, poor attention has been paid to the roles of autophagy-related lncRNAs in breast cancer.

Objective

This study aimed to construct an autophagy-related lncRNA signature that can effectively predict the prognosis of breast cancer patients and explore the potential functions of these lncRNAs.

Methods

The RNA sequencing (RNA-Seq) data of breast cancer patients was collected from The Cancer Genome Atlas (TCGA) database and the GSE20685 database. Multivariate Cox analysis was implemented to produce an autophagy-related lncRNA signature in the TCGA cohort. The signature was then validated in the GSE20685 cohort. The receiver operator characteristic (ROC) curve was performed to evaluate the predictive ability of the signature. Gene set enrichment analysis (GSEA) was used to explore the potential functions based on the signature. Finally, the study developed a nomogram and internal verification based on the autophagy-related lncRNAs.

Results

A signature composed of 9 autophagy-related lncRNAs was determined as a prognostic model, and 1,109 breast cancer patients were divided into high-risk group and low-risk group based on median risk score of the signature. Further analysis demonstrated that the over survival (OS) of breast cancer patients in the high-risk group was poorer than that in the low-risk group based on the prognostic signature. The area under the curve (AUC) of ROC curve verified the sensitivity and specificity of this signature. Additionally, we confirmed the signature is an independent factor and found it may be correlated to the progression of breast cancer. GSEA showed gene sets were notably enriched in carcinogenic activation pathways and autophagy-related pathways. The qRT-PCR identified 5 lncRNAs with significantly differential expression in breast cancer cells based on the 9 lncRNAs of the prognostic model, and the results were consistent with the tissues.

Conclusion

In summary, our signature has potential predictive value in the prognosis of breast cancer and these autophagy-related lncRNAs may play significant roles in the diagnosis and treatment of breast cancer.

lncRNA XIST regulates cell proliferation, migration and invasion via regulating miR-30b and RECK in nasopharyngeal carcinoma

Long non-coding RNA (lncRNA) X-inactive specific transcript (XIST) plays an essential role in the development and progress of nasopharyngeal carcinoma (NPC). MicroRNA-30b (miR-30b) has been confirmed to play an inhibitory role in various types of cancer. The molecular mechanisms underlying the lncRNA XIST-mediated regulation of the metastasis of NPC cells by miR-30b is not clear. qPCR and western blot analysis were used to detect the expression of XIST, miR-30b, and reversion inducing cysteine rich protein with kazal motifs (RECK) in NPC tissues and cell lines. The detection of luciferase reporter gene confirmed the relationship between lncRNA XIST, miR-30b and RECK. CCK-8 and Transwell assays were performed in order to detect the proliferation, migration and invasion of the NPC cells. The results of qPCR and western blotting indicated that the expression levels of lncRNA XIST and RECK were higher in the NPC tissues and cell lines than that of the control group, while the expression of miR-30b was lower. Knockdown of lncRNA XIST significantly inhibited cell proliferation, migration and invasion in the NPC cell lines. In addition, lncRNA XIST was found to negatively regulate the expression of miR-30b, resulting in the upregulation of RECK. Overexpression of RECK was found to reverse the inhibitory effect of lncRNA XIST knockdown or miR-30b on NPC cell metastasis. Our results showed that cell migration and invasion were inhibited by knockdown of lncRNA XIST, suggesting that the lncRNA XIST/miR-30b/RECK axis is involved in the development of NPC.

The critical roles of lncRNAs in the development of osteosarcoma

Osteosarcoma is rare malignancy of childhood and adolescence, with high morbidity and mortality despite accomplishment of diverse therapeutic modalities. Identification of the underlying mechanism of osteosarcoma evolution would help in better management of this rare malignancy. Lots of investigations have described abnormal regulation of long non-coding RNAs (lncRNAs) in clinical specimens of osteosarcoma and the established cell lines. This malignancy has been associated with over-expression of TUG1, LOXL1-AS1, MIR100HG, NEAT1, HULC, ANRIL and a number of other lncRNAs, while under-expression of lots of lncRNAs including LncRNA-p21, FER1L4, GAS5, LncRNA NR_136400 and LINC-PINT. Expression amounts of LUCAT1, LINC00922, SNHG12, FOXC2-AS1 and OIP5-AS1 lncRNAs have been associated with response to a number of chemotherapeutic agents. Taken together, lncRNAs are possible targets for proposing novel advanced therapeutic modalities for osteosarcoma.

miR-30d-5p suppresses proliferation and autophagy by targeting ATG5 in renal cell carcinoma

Previous reports have shown that miR-30d-5p functions as a tumor suppressor in prostate cancer and gallbladder carcinoma, but its role in renal cell carcinoma (RCC) remains elusive. This study was designed to explore the functional role of miR-30d-5p in proliferation and autophagy of RCC. Our results show that miR-30d-5p is significantly down-regulated in RCC tissues compared with normal tissues. miR-30d-5p overexpression suppressed cell proliferation, cell-cycle G1/S transition and autophagy, but promoted apoptosis in RCC cell lines (786-O and ACHN). Intriguingly, autophagy-related gene 5 (ATG5) was directly targeted by miR-30d-5p, as shown using luciferase reporter assay and biotin-avidin pull-down assay. Moreover, overexpression of ATG5 attenuated the inhibitory effect of miR-30d-5p on proliferation and autophagy in 786-O cells. These results suggest that miR-30d-5p suppresses proliferation and autophagy in RCC cells by targeting ATG5, and this pathway may be a suitable basis for the design of novel cancer therapeutics.

IncRNA MAPKAPK5-AS1 promotes proliferation and migration of thyroid cancer cell lines by targeting miR-519e-5p/YWHAH

Thyroid cancer is a common malignant tumour of the endocrine system and ranks ninth in cancer incidence worldwide. An extensive body of evidence has demonstrated that lncRNAs play a critical role in the progression of thyroid cancer. The lncRNA MAPKAPK5-AS1 has been reported to be abnormally expressed and to play a role in the development of various human cancers. However, MAPKAPK5-AS1's potential role in thyroid cancer progression remains unknown. The objective of our study was to explore the role and mechanism of MAPKAPK5-AS1 in thyroid cancer cells and provide a potential target for its biological diagnosis and treatment. We transfected sh-MAPKAPK5-AS1 and sh-NC into BCPAP and TPC-1 cells for loss-of-function assays. Results of RT-qPCR analysis demonstrated that MAPKAPK5-AS1 was more highly expressed in thyroid cancer cells compared to normal cells. Functional assays demonstrated that interfering with the expression of MAPKAPK5-AS1 notably repressed proliferation and invasion and accelerated apoptosis of BCPAP and TPC-1 cells. Mechanistically, we found that miR-519e-5p was negatively regulated by MAPKAPK5-AS1 and that tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein eta (YWHAH) was a target of miR-519e-5p. Additionally, rescue assays demonstrated that downregulation of MAPKAPK5-AS1 expression inhibited cell proliferation, migration, and invasion and promoted apoptosis by sponging miR-519e-5p, thereby increasing YWHAH expression. Ultimately, our study revealed that MAPKAPK5-AS1 promotes proliferation and migration of thyroid cancer cells by targeting the miR-519e-5p/YWHAH axis, which provides novel insight into the development and progression of thyroid cancer.

Expression of NF-κB associated lncRNAs in schizophrenia

NF-κB signaling pathway has important roles in the regulation of growth and development of nervous system. This pathway has also been shown to participate in the pathogenesis of schizophrenia. Meanwhile, activity of NF-κB signaling pathway is regulated by several factors including non-coding RNAs (lncRNAs). In the current study, we evaluated expression of nine NF-κB-related lncRNAs namely DILC, ANRIL, PACER, CHAST, ADINR, DICER1-AS1, HNF1A-AS1, H19 and NKILA as well as two mRNA coding genes namely ATG5 and CEBPA in the peripheral blood of patients with schizophrenia compared with matched healthy subjects. Expressions of these genes were assessed by real time PCR technique. Expression of PACER was lower in patients with schizophrenia compared with controls (Posterior beta = − 0.684, P value = 0.049). On the other hand, expressions of CHAST, CEBPA, H19, HNF1A-AS1 and DICER1-AS1 were higher in patients compared with controls (Posterior beta = 0.39, P value = 0.005; Posterior beta = 0.844, P value < 0.0001; Posterior beta = 0.467, P value < 0.0001; Posterior beta = 1.107, P value = 0.005; Posterior beta = 0.176, P value = 0.044, respectively). We also appraised the diagnostic power of transcript quantities of CHAST, CEBPA, DICER1-AS1, H19 and HNF1A-AS1 in distinguishing between patients with schizophrenia and controls through depicting ROC curves. Based on the area under curve (AUC) values, CEBPA had the best diagnostic power (AUC = 0.948, P < 0.0001), followed by H19 (AUC = 0.815, P < 0.0001). Taken together, our study demonstrated dysregulation of NF-κB-related lncRNAs and genes in the peripheral blood of patients with schizophrenia and their potential as peripheral markers for this psychiatric condition.

Upregulation of FTX Promotes Osteosarcoma Tumorigenesis by Increasing SOX4 Expression via miR-214-5p

BACKGROUND

Long-chain non-coding RNA (LncRNA) plays a key role in the biological processes of tumors. LncRNA-FTX has been the invasion of tumors. However, its function and mechanism in osteosarcoma have not been studied.

METHODS

qRT-PCR was measured the expression levels of FTX and miR-214-5p in osteosarcoma. The protein levels of SRY-related HMG box transcription factor 4 (SOX4) were detected by Western Blot. Cholecystokinin (CCK-8) assay, cell colony formation and Transwell assay, Annexin V-FITC/PI assay were analyzed the effects of FTX and miR-214-5p on cell proliferation, cell invasion and apoptosis. The relationship between FTX, miR-214-5p and SOX4 was analyzed by bioinformatics analysis and Luciferase. The tumor changes in mice were detected by vivo experiments in nude mice.

RESULTS

The expression levels of FTX were increased in osteosarcoma tissues and cell lines and negatively correlated with the expression levels of miR-214-5p. FTX could modulate the expression of miR-214-5p in osteosarcoma cell lines. sh-FTX inhibited the growth and metastasis of osteosarcoma. FTX could regulate the growth of osteosarcoma through miR-214-5p. The knockdown of miR-214-5p reversed the inhibitory effect of sh-FTX on osteosarcoma cell proliferation and growth in mice. Furthermore, FTX regulated the expression of SOX4 by acting as a sponge of miR-214-5p in osteosarcoma.

CONCLUSION

FTX could promote proliferation, invasion and inhibited apoptosis by regulating miR-214-5p/SOX4 axis in osteosarcoma, suggesting that FTX might be a potential target for osteosarcoma treatment.

DICER-AS1 lncRNA: A putative culprit in the pathogenesis of gastric cancer

The nuclear factor-κB (NF-κB) has a pivotal role in the pathogenesis of several cancers including gastric cancer. We have recently reported dysregulation of a number of NF-κB-associated lncRNAs in a variety of human disorders including breast cancer and coronary artery disease. In the current study, we evaluated expression of five NF-κB-associated lncRNAs (CHAST, ADINR, DICER1-AS1, HNF1A-AS1 and NKILA) and two NF-κB-associated-mRNA coding genes (CEBPA and ATG5) in gastric cancer tissues and their paired non-cancerous tissues using real time PCR method. Expression of DICER-AS1 was significantly down-regulated in gastric cancer tissues compared with the corresponding non-cancerous tissues (Expression ratio = 0.23, P value = .01). Expressions of other genes were not significantly different between these two sets of samples. Relative expression of DICER1-AS1 in cancer tissues versus non-cancerous tissues tended to associated with histological grade (P = .05). Tumoral expression levels of NKILA, ADINR, CEBPA and HNF1A-AS1 were significantly higher in patients with positive family history of cancer compared with those without such history (P values = .03, 0.02, 0.02 1nd 0.03, respectively). Besides, expression levels of NKILA, ADINR, DICER1-AS1, CEBPA, CHAST, HNF1A-AS1 and ATG5 were lower in H. pylori-infected tissues (P values = .01, 0.02, 0.03, 0.01, 0.004, 0.004 and 0.04, respectively). The lowest tumoral expression of DICER1-AS1 was detected in stage II cancers, while the highest expression of this lncRNA was reported in a single stage I tumor tissue. Similar pattern of expression was detected for ATG5. Significant pairwise correlations were demonstrated between expression levels of NF-ƙB-associated genes in both gastric cancer tissues and non-cancerous tissues. Expression levels of DICER1-AS1 had sensitivity and specificity values of 63.3% and 63.3% in differentiating between tumoral and non-tumoral tissues (Estimate criterion>6.96, J = 0.27, P value = .01, AUC = 0.67). Although previous studies have reported involvement of NF-κB pathway in the pathogenesis of gastric cancer, among the reported lncRNAs associated with this pathway, we could only detect differential expression of DICER1-AS1 between tumoral and non-tumoral tissues. Thus, the mechanism underlying dysregulation of this pathway might be different among various cancers.

Implications of Long Non-Coding RNAs in Age-Altered Proteostasis

This review aims to summarize the current knowledge on how lncRNAs are influencing aging and cancer metabolism. Recent research has shown that senescent cells re-enter cell-cycle depending on intrinsic or extrinsic factors, thus restoring tissue homeostasis in response to age-related diseases (ARDs). Furthermore, maintaining proteostasis or cellular protein homeostasis requires a correct quality control (QC) of protein synthesis, folding, conformational stability, and degradation. Long non-coding RNAs (lncRNAs), transcripts longer than 200 nucleotides, regulate gene expression through RNA-binding protein (RBP) interaction. Their association is linked to aging, an event of proteostasis collapse. The current review examines approaches that lead to recognition of senescence-associated lncRNAs, current methodologies, potential challenges that arise from studying these molecules, and their crucial implications in clinical practice.

Functional Genetic Variant in ATG5 Gene Promoter in Acute Myocardial Infarction

Coronary artery disease (CAD) including acute myocardial infarction (AMI) is an inflammatory and metabolic disease mainly caused by atherosclerosis. Dysfunctional autophagy has been associated with abnormal lipid metabolism and inflammation. In previous studies, we have reported altered autophagic activity in AMI patients. As autophagy-related protein 5 (ATG5) is a core protein in autophagy, we speculated that altered ATG5 level may contribute to CAD and AMI development. In this study, the promoter of the ATG5 gene was genetically and functionally investigated in large groups of AMI patients (n = 378) and ethnic-matched healthy controls (n = 386). The results showed that a total of 15 genetic variants including 6 single-nucleotide polymorphisms (SNPs) in the ATG5 gene promoter were found in this study population. A novel deletion variant (g.106326168_70delTCT) and an SNP [g.106325757C > G (rs190825454)] were found in one 66-year-old male patient with non-ST-segment elevated AMI, but in none of controls. In cultured HEK-293 and H9c2 cells, the deletion variant significantly decreased the transcriptional activity of the ATG5 gene promoter (P < 0.01). In contrast, the genetic variants either identified only in controls or found in both AMI patients and controls did not affect the transcriptional activity of the ATG5 gene promoter (P > 0.05). Furthermore, an electrophoretic mobility shift assay showed that the deletion variant evidently affected the binding of a transcription factor. Therefore, the genetic variant identified in AMI may affect the activity of the ATG5 gene promoter and change the ATG5 level, contributing to AMI as a rare risk factor.

Autophagy regulation by microRNAs: Novel insights into osteosarcoma therapy

Osteosarcoma (OS) is a kind of primary bone cancer that is considered as the leading cause of children death. Surgery and chemotherapy are considered as common treatment approaches for OS; the rate of survival for patients is almost 60-70%. Besides the used therapeutic approaches, it seems that there is a crucial need to launch new treatments for OS. In this regard, more understanding about cellular and molecular pathways involved in OS can contribute to recovery and develop new therapeutic platforms. Autophagy is a cellular machinery that digests and degrades dysfunctional proteins and organelles, so it can regulate the cell proliferation and survival. Most of the time, OS cells use autophagy to increase their survival and proliferation and to gain the ability to resist chemotherapy. Although, there are several controversial evidences on how OS cells use autophagy. A variety of cellular and molecular pathways, that is, microRNAs (miRNAs) can modulate autophagy. MiRNAs are some endogenous, approximately 22 nucleotide RNAs that have an important role in posttranscriptional regulation of mRNAs by targeting them. There are many evidences that the various miRNA expressions in OS cells are dysregulated, so it can propel a normal cell to cancerous one by influencing the cell survival, apoptosis, and autophagy, and eventually increased chemoresitance. Hence, miRNAs can be considered as new biomarkers for OS diagnosis, and according to the role of autophagy in OS progression, miRNAs can use inhibiting or promoting autophagy agents. The present review summarizes the effects of aberrant expression of miRNAs in OS diagnosis and treatment with focus on their roles in autophagy.

Autophagy in aging and longevity

Our understanding of the process of autophagy and its role in health and diseases has grown remarkably in the last two decades. Early work established autophagy as a general bulk recycling process which involves the sequestration and transport of intracellular material to the lysosome for degradation. Currently, autophagy is viewed as a nexus of metabolic and proteostatic signalling that can determine key physiological decisions from cell fate to organismal lifespan. Here, we review the latest literature on the role of autophagy and lysosomes in stress response and longevity. We highlight the connections between autophagy and metabolic processes, the network associated with its regulation, and the links between autophagic dysfunction, neurodegenerative diseases, and aging.

MicroRNAs as major regulators of the autophagy pathway

Autophagy is a cellular stress response mechanism activation of which leads to degradation of cellular components, including proteins as well as damaged organelles in lysosomes. Defects in autophagy mechanisms were associated with several pathologies (e.g. cancer, neurodegenerative diseases, and rare genetic diseases). Therefore, autophagy regulation is under strict control. Transcriptional and post-translational mechanisms that control autophagy in cells and organisms studied in detail. Recent studies introduced non-coding small RNAs, and especially microRNAs (miRNAs) in the post-translational orchestration of the autophagic activity. In this review article, we analyzed in detail the current status of autophagy-miRNA connections. Comprehensive documentation of miRNAs that were directly involved in autophagy regulation resulted in the emergence of common themes and concepts governing these complex and intricate interactions. Hence, a better and systematic understanding of these interactions reveals a central role for miRNAs in the regulation of autophagy.

Long Non Coding RNA SNHG16 Facilitates Proliferation, Migration, Invasion and Autophagy of Neuroblastoma Cells via Sponging miR-542-3p and Upregulating ATG5 Expression

Background

Neuroblastoma (NB) is a heterogeneous pediatric malignant tumor with many biological and clinical characteristics. Long non-coding RNA small nucleolar RNA host gene 16 (SNHG16) plays vital role in the development of NB. However, the potential mechanism of SNHG16 in the progression of NB is rarely reported.

Methods

The expression levels of SNHG16, miR-542-3p and autophagy-related gene 5 (ATG5) were measured with quantitative real-time polymerase chain reaction (qRT-PCR). The proliferation, migration and invasion of NB cells were determined using 3-(4, 5-dimethylthiazol-2-YI)-2, 5-diphenyltetrazolium bromide (MTT) or transwell assay. Protein levels of ATG5, microtubule-associated protein A1/1B-light chain3 (LC3-I/II) and p62 were detected by Western blot analysis. The interaction between miR-542-3p and SNHG16 or ATG5 was predicted by starBase and confirmed by dual luciferase reporter assay. Xenograft mice models were constructed to confirm the role of SNHG16 in vivo.

Results

SNHG16 was upregulated in NB tissues and cells and associated with clinical stage and poor prognosis of NB. Knockdown of SNHG16 impeded proliferation, migration, invasion and autophagy of NB cells in vitro, and suppressed tumor growth in vivo. Interestingly, SNHG16 mediated ATG5 expression through sponging miR-542-3p in NB cells. Moreover, miR-542-3p downregulation reversed the inhibitory effects of SNHG16 silencing on proliferation, migration, invasion and autophagy of NB cells. Besides, ATG5 overturned the regulatory effects on proliferation, migration, invasion and autophagy of NB cells induced by SNHG16 or miR-542-3p knockdown.

Conclusion

SNHG16 facilitated proliferation, migration, invasion and autophagy of NB cells via sponging miR-542-3p and upregulating ATG5 expression in NB.

Long noncoding RNA ZFAS1 promotes tumorigenesis and metastasis in nasopharyngeal carcinoma by sponging miR-892b to up-regulate LPAR1 expression

OBJECTIVE

In this study, we explored the NPC-specific expression of ZFAS1 and the mechanism of ZFAS1-mediated growth, aggressiveness and tumorigenesis in NPC.

METHODS

The expression profile of lncRNAs was detected in NPC tissues and matching para-carcinoma tissues using microarray analysis. LncRNA-miRNA and miRNA-mRNA interaction networks were constructed using the miRcode v11 and TargetScanHuman v7.2 web server and then validated using dual-luciferase assay. Western blot and RT-qPCR were performed to detect protein and RNA expression. The effects of ZFAS1, miR-892b and LPAR1 dysregulation on the proliferative, migratory and invasive abilities of NPC cells were observed using colony formation, cell counting kit-8 (CCK-8) and transwell assays in vitro. In vivo, a xenograft nude mouse model was established to detect the impact of ZFAS1 dysregulation on the tumorigenicity of NPC cells.

RESULTS

The expression of multiple lncRNAs, of which ZFAS1 was up-regulated, was dysregulated in NPC tissues. ZFAS1 directly targeted miR-892b, and miR-892b negatively regulated the expression of downstream LPAR1. The proliferation, migration and invasion of NPC cells could be largely enhanced by the downregulation of miR-892b as well as the up-regulation of ZFAS1 and LPAR1, while the overexpression of miR-892b and the downregulation of ZFAS1 and LPAR1 decreased these abilities. In nude mice, the growth of tumour xenografts formed by HONE1 cells was significantly suppressed when ZFAS1 was silenced.

CONCLUSION

The study demonstrated that lncRNA ZFAS1 may act as a promoter of tumorigenesis and metastasis in nasopharyngeal carcinoma, by up-regulating the expression of LPAR1 in a miR-892b-dependent manner.

lncRNAVNN3 mediated benzene-induced hematotoxicity through promoting autophagy and apoptosis

The potential toxicity of low-dose benzene exposure to human health has received attention, but the mechanisms of low-dose benzene-induced hematotoxicity remain largely unknown. The purpose of our study was to investigate the relationships between lncRNAVNN3 expression with benzene-induced autophagy and apoptosis in control and benzene-exposed workers. Seventy benzene-exposed workers and seventy non-benzene-exposed healthy workers were recruited. The expression of lncRNAVNN3, serum autophagy-associated and apoptosis-associated proteins were evaluated, and the relationship among them were also analysed. Furthermore, the mechanism of lncRNAVNN3 on autophagy and apoptosis induced by benzene metabolite (1, 4-benzoquinone, 1, 4-BQ) was investigated in vitro. The results showed that the expression of lncRNAVNN3 increased in benzene-exposed workers (p < 0.05). A positive correlation was found between lncRNAVNN3, serum autophagy-associated and apoptosis-associated proteins. In addition, we found that the knockdown of lncRNAVNN3 reduced phosphorylation of beclin1 and Bcl-2, which mediated 1, 4-benzoquinone-induced autophagy and apoptosis. Overall, lncRNAVNN3 mediated 1, 4-benzoquinone-induced autophagy and apoptosis though regulating phosphorylation of beclin1 and Bcl-2, suggesting that lncRNAVNN3 might be a novel early sensitive biomarker of benzene-induced hematotoxicity.

Expression analysis of NF-κB interacting long noncoding RNAs in breast cancer

The nuclear factor-κB (NF-κB) has a prominent role in development of breast cancer and response of patients to conventional therapies. Several factors regulate the activity of this transcription factor. In the current investigation, we compared expression levels of five long non-coding RNAs (lncRNAs) with putative interactions with NF-κB namely CHAST, ADINR, DICER1-AS1, HNF1A-AS1 and NKILA between 78 breast cancer tissues and their paired adjacent non-cancerous tissues (ANCTs). We also assessed expression levels of ATG5 and CEBPA mRNA coding genes that are functionally linked with NF-κB signaling in these two sets of samples. All assessed genes except for NKILA were significantly down-regulated in tumoral tissues compared with ANCTs. Expression of NKILA was not significantly different between tumoral tissues and ANCTs. Expression levels of CEBPA and HNF1A-AS were significantly associated with cancer stage (P values of 0.03 and 0.02 respectively). Expression levels of ATG5 tended to be associated with mitotic rate (P = .05). The association between expression levels of ATG5 and tumor size was also significant (P = .02). Expression of CHAST was significantly associated with PR status (P = .04) and tended to be associated with ER status (P = .05). Finally, expression of NKILA was significantly associated with first pregnancy age (P = .01). No other significant association was detected between expression levels of assessed genes and clinical parameters. Expression levels of mentioned genes were significantly correlated with each other. The most significant correlations were found between CHAST and ADINR (correlation coefficients of 0.78 and 0.69 in tumoral tissues and ANCTs respectively). Based on the area under curve (AUC) values, DICER1-AS and CEBPA had the best performance in differentiation of tumoral tissues from ANCTs (AUC values of 0.92 and 0.90 respectively. Combination of transcript quantities of six genes could differentiate these two sets of samples with 92.3% sensitivity, 91% specificity and diagnostic power of 95%. The current project highlights dysregulation of NF-κB-associated genes in breast cancer tissues and suggests them as potential diagnostic markers in breast cancer.

Dysregulation of autophagy-related lncRNAs in peripheral blood of coronary artery disease patients

Coronary artery disease (CAD) as a major cause of death has been associated with dysregulation of several processes among them is autophagy. In the current study, we assessed expression of autophagy related gene 5 (ATG5) and three ATG5-associated long non-coding RNAs (lncRNAs Chast, HULC and DICER1-AS1) in the peripheral blood of patients with premature CAD and healthy subjects. Expression levels of ATG5, Chast, HULC and DICER1-AS1 were significantly lower in peripheral blood of CAD cases compared with healthy subjects. Receiver Operating Characteristic (ROC) curve analysis showed that HULC and DICER1-AS1 can properly differentiate CAD patients from healthy subjects (area under curve (AUC) values of 0.90 and 0.87, respectively). Expression levels of ATG5 and Chast were inversely correlated with FBS levels (r = -0.41, P < 0.0001 and r = -0.38, P < 0.0001 respectively) but no other biochemical factors. Expression of DICER1-AS1 was inversely correlated with FBS (r = -0.54, P < 0.0001), TG (r = -0.29, P < 0.0001) and TG/HDL ratio (r = -0.27, P < 0.0001). Expression of HULC was inversely correlated with age (r = -0.24, P < 0.0001), FBS (r = -0.62, P < 0.0001) and TG (r = -0.31, P < 0.0001). There were significant pairwise correlations between expression levels of all genes. The most robust correlations were detected ATG5 and Chast (r = 0.81, P < 0.0001) and between DICER1-AS1 and HULC (r = 0.75, P < 0.0001). The current study further verified associations between dysregulation of autophagy and CAD. Moreover, our results indicate appropriateness of two autophagy-related lncRNAs for differentiation of CAD status.

miRNA signatures in childhood sarcomas and their clinical implications

Progresses in multimodal treatments have significantly improved the outcomes for childhood cancer. Nonetheless, for about one-third of patients with Ewing sarcoma, rhabdomyosarcoma, or osteosarcoma steady remission has remained intangible. Thus, new biomarkers to improve early diagnosis and the development of precision-targeted medicine remain imperative. Over the last decade, remarkable progress has been made in the basic understanding of miRNAs function and in interpreting the contribution of their dysregulation to cancer development and progression. On this basis, this review focuses on what has been learned about the pivotal roles of miRNAs in the regulation of key genes implicated in childhood sarcomas.

Role of autophagy in osteosarcoma

Osteosarcoma (OS) is the most common primary bone tumour in children and adolescents. It is a highly aggressive tumor with a tendency to spread to the lungs, which are the most common site of metastasis. Advanced osteosarcoma patients with metastasis share a poor prognosis. Despite the use of chemotherapy to treat OS, the 5-year overall survival rate for patients has remained unchanged at 65–70% for the past 20 years. In addition, the 5-year survival of patients with a metastatic disease is around 20%, highlighting the need for novel therapeutic targets.

Autophagy is an intracellular degradation process which eliminates and recycles damaged proteins and organelles to improve cell lifespan. In the context of cancer, numerous studies have demonstrated that autophagy is used by tumor cells to repress initial steps of carcinogenesis and/or support the survival and growth of established tumors. In osteosarcoma, autophagy appears to be deregulated and could also act both as a pro or anti-tumoral process. In this manuscript, we aim to review these major findings regarding the role of autophagy in osteosarcoma.

SP1-induced upregulation of long non-coding RNA HCP5 promotes the development of osteosarcoma

Long non-coding RNAs (LncRNAs) are acknowledged as crucial regulators in tumorigenesis and tumor progression. In this study, we explored the mechanism and function of lncRNA HCP5 in osteosarcoma (OS). At first, five lncRNAs were chosen from GeneCard and subjected to qRT-PCR examination. The results indicated that HCP5 was significantly overexpressed in four OS cell lines. Northern blot assay further proved the higher expression of HCP5 in OS cell lines. To identify the biological role of HCP5 in OS, we silenced the expression of HCP5 in U2OS and MG-63 cells which possessed the highest level of HCP5. CCK-8 and colony formation assay revealed the inhibitory effect of HCP5 knockdown on cell proliferation. Cell apoptosis was found to be increased in cells transfected with sh-HCP5#1. Moreover, cell invasion and epithelial-mesenchymal transition (EMT) were reversed by the silencing of HCP5. The results of functional assays showed that HCP5 acted as an oncogene in osteosarcoma. Mechanically, HCP5 was found to be activated by the transcription factor SP1. Finally, rescue assays were conducted to demonstrate the function of SP1/HCP5 axis in osteosarcoma. In conclusion, we confirmed that SP1-induced upregulation of long non-coding RNA HCP5 promotes the development of osteosarcoma.

miR-34a inhibits progression of neuroblastoma by targeting autophagy-related gene 5

Neuroblastoma (NB) is a common pediatric malignancy with high mortality in childhood. Although many attentions have been gained, novel biomarkers for NB diagnosis and prognosis are still needed. microRNAs (miRNAs) played important roles in NB progression and miR-34a is a tumor suppressor in NB. However, the mechanism that underlies miR-34a regulating proliferation, migration, invasion and autophagy in NB remains poorly understood. In this study, cell proliferation was investigated by MTT and colony assay. Cell apoptosis was measured by caspase 3 activity assay. Cell migration and invasion were detected by trans-well analysis. Autophagy was measured via GFP-LC3 puncta fluorescence assay and western blots (WB). The expression of miR-34a was examined by quantitative real-time PCR (qRT-PCR). The regulatory effect of miR-34a on autophagy-related gene 5 (ATG5) was detected by qRT-PCR and WB. The interaction between miR-34a and ATG5 was probed by luciferase activity and RNA immunoprecipitation (RIP) assay. Results showed that miR-34a expression was inhibited in NB tissues and cells with low survival rate. Addition of miR-34a suppressed cell proliferation, migration, invasion and autophagy but promoted apoptosis in NB cells, whereas miR-34a deficiency played opposite roles in NB progression. Intriguingly, ATG5 was directly targeted by miR-34a. Moreover, ATG5 restoration attenuated miR-34a-mediated inhibitory effect on proliferation, apoptosis, migration, invasion and autophagy. These results indicated miR-34a suppressed proliferation, apoptosis, migration, invasion and autophagy in NB cells by targeting ATG5, providing a novel therapeutic avenue for NB treatment.

Epitranscriptomic Signatures in lncRNAs and Their Possible Roles in Cancer

In contrast to the amazing exponential growth in knowledge related to long non-coding RNAs (lncRNAs) involved in cell homeostasis or dysregulated pathological states, little is known so far about the links between the chemical modifications occurring in lncRNAs and their function. Generally, ncRNAs are post-transcriptional regulators of gene expression, but RNA modifications occurring in lncRNAs generate an additional layer of gene expression control. Chemical modifications that have been reported in correlation with lncRNAs include m⁶A, m⁵C and pseudouridylation. Up to date, several chemically modified long non-coding transcripts have been identified and associated with different pathologies, including cancers. This review presents the current level of knowledge on the most studied cancer-related lncRNAs, such as the metastasis associated lung adenocarcinoma transcript 1 (MALAT1), the Hox transcript antisense intergenic RNA (HOTAIR), or the X-inactive specific transcript (XIST), as well as more recently discovered forms, and their potential roles in different types of cancer. Understanding how these RNA modifications occur, and the correlation between lncRNA changes in structure and function, may open up new therapeutic possibilities in cancer.

Long Non-coding RNAs Contribute to the Inhibition of Proliferation and EMT by Pterostilbene in Human Breast Cancer

Background: There is increasing evidence that long non-coding RNAs (lncRNAs) are involved in the process of carcinogenesis and treatment using chemotherapy. Pterostilbene, a phytochemical agent with natural antioxidant and anti-inflammatory properties, has been shown to modulate oncogenic processes in many cancers. However, there has been limited research on the association between pterostilbene and the expression of lncRNAs.

Methods: MCF7 breast cancer cells were treated with various concentrations of pterostilbene and their gene expression profile was analyzed by quantitative real-time PCR, Western blotting and immunofluorescence.

Results: Treatment with pterostilbene inhibited cell proliferation and epithelial-to-mesenchymal transition (EMT), and increased cell apoptosis, autophagy and ER stress. The Akt/mTOR pathway was downregulated, but p38 MAPK/Erk signaling was activated in cells following treatment with pterostilbene. Pterostilbene increased the expression of the lncRNAs MEG3, TUG1, H19, and DICER1-AS1 whereas the expression of LINC01121, PTTG3P, and HOTAIR declined. Knockdown of lncRNA H19 resulted in a reduction of the cell invasion, with the cells becoming more sensitive to pterostilbene therapy.

Conclusions: These results suggest that efficient optimum disruption of lncRNA expression might possibly improve the anti-tumor effects of phytochemical agents, thus serving as a potential therapy for breast cancer.