LncRNA PVT1 triggers Cyto-protective autophagy and promotes pancreatic ductal adenocarcinoma development via the miR-20a-5p/ULK1 Axis

The roles of lncRNAs and miRNAs in pancreatic cancer: a focus on cancer development and progression and their roles as potential biomarkers

Pancreatic ductal adenocarcinoma (PDAC) is among the most penetrative malignancies affecting humans, with mounting incidence prevalence worldwide. This cancer is usually not diagnosed in the early stages. There is also no effective therapy against PDAC, and most patients have chemo-resistance. The combination of these factors causes PDAC to have a poor prognosis, and often patients do not live longer than six months. Because of the failure of conventional therapies, the identification of key biomarkers is crucial in the early diagnosis, treatment, and prognosis of pancreatic cancer. 65% of the human genome encodes ncRNAs. There are different types of ncRNAs that are classified based on their sequence lengths and functions. They play a vital role in replication, transcription, translation, and epigenetic regulation. They also participate in some cellular processes, such as proliferation, differentiation, metabolism, and apoptosis. The roles of ncRNAs as tumor suppressors or oncogenes in the growth of tumors in a variety of tissues, including the pancreas, have been demonstrated in several studies. This study discusses the key roles of some lncRNAs and miRNAs in the growth and advancement of pancreatic carcinoma. Because they are involved not only in the premature identification, chemo-resistance and prognostication, also their roles as potential biomarkers for better management of PDAC patients.

LncRNA PVT1 promotes bladder cancer progression by forming a positive feedback loop with STAT5B

BACKGROUND

Plasmacytoma Variant Translocation 1 (LncRNA PVT1) and signal transducer and activator of transcription 5B (STAT5B) play important roles in various cancers, but their interaction in bladder cancer (BC) remains unclear.

PURPOSE

We aimed to explore the interaction between lncRNA PVT1 and STAT5B in BC tumorigenesis and find potential drugs for BC.

METHODS

The association of the expression of lncRNA PVT1 and STAT5B to the prognosis of BC patients was evaluated via bioinformatic analysis. Loss- and gain-of-function assays were performed to determine the biological functions of lncRNA PVT1 and STAT5B. Quantitative real time polymerase chain reaction, Western blot, immunohistochemistry, and immunofluorescence were used to detect lncRNA PVT1 and STAT5B expression. Fluorescence in situ hybridization, RNA pull-down and RNA immunoprecipitation assays were conducted to determine the regulatory effect of lncRNA PVT1 on STAT5B. The transcriptional effect of STAT5B on lncRNA PVT1 gene was determined using luciferase reporter assay, chromatin immunoprecipitation and DNA-affinity precipitation assays. Connectivity Map analysis was used to screen anticancer drugs.

RESULTS

LncRNA PVT1 and STAT5B enhance the expression of each other and promote the malignant phenotypes in BC, including cell viability and invasion. lncRNA PVT1 stabilizes STAT5B by decreasing ubiquitination, enhances STAT5B phosphorylation, and promotes the translocation to the nucleus of STAT5B to trigger further carcinogenesis activities. In the nucleus, STAT5B activates the transcription of lncRNA PVT1 by binding directly to its promoter region, leading to a positive feedback. Tanespimycin effectively abated the oncogenic effect.

CONCLUSIONS

We first identified the lncRNA PVT1/STAT5B positive feedback loop for bladder carcinogenesis, and found a potentially effective drug for BC.

An Evaluation on the Role of Non-Coding RNA in HIV Transcription and Latency: A Review

The existence of latent cellular reservoirs is recognized as the major barrier to an HIV cure. Reactivating and eliminating "shock and kill" or permanently silencing "block and lock" the latent HIV reservoir, as well as gene editing, remain promising approaches, but so far have proven to be only partially successful. Moreover, using latency reversing agents or "block and lock" drugs pose additional considerations, including the ability to cause cellular toxicity, a potential lack of specificity for HIV, or low potency when each agent is used alone. RNA molecules, such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are becoming increasingly recognized as important regulators of gene expression. RNA-based approaches for combatting HIV latency represent a promising strategy since both miRNAs and lncRNAs are more cell-type and tissue specific than protein coding genes. Thus, a higher specificity of targeting the latent HIV reservoir with less overall cellular toxicity can likely be achieved. In this review, we summarize current knowledge about HIV gene expression regulation by miRNAs and lncRNAs encoded in the human genome, as well as regulatory molecules encoded in the HIV genome. We discuss both the transcriptional and post-transcriptional regulation of HIV gene expression to align with the current definition of latency, and describe RNA molecules that either promote HIV latency or have anti-latency properties. Finally, we provide perspectives on using each class of RNAs as potential targets for combatting HIV latency, and describe the complexity of the interactions between different RNA molecules, their protein targets, and HIV.

Autophagy as a self-digestion signal in human cancers: Regulation by microRNAs in affecting carcinogenesis and therapy response

Autophagy is defined as a "self-digestion" signal, and it is a cell death mechanism its primary function is degrading toxic agents and aged organelles to ensure homeostasis in cells. The basic leve ls of autophagy are found in cells, and when its levels exceed to standard threshold, cell death induction is observed. Autophagy dysregulation in cancer has been well-documented, and regulation of this pathway by epigenetic factors, especially microRNAs (miRNAs), is interesting and noteworthy. miRNAs are considered short endogenous RNAs that do not encode functional proteins, and they are essential regulators of cell death pathways such as apoptosis, necroptosis, and autophagy. Accumulating data has revealed miRNA dysregulation (upregulation or downregulation) during tumor progression, and their therapeutic manipulation provides new insight into cancer therapy. miRNA/autophagy axis in human cancers has been investigated an exciting point is the dual function of both autophagy and miRNAs as oncogenic and onco-suppressor factors. The stimulation of pro-survival autophagy by miRNAs can increase the survival rate of tumor cells and mediates cancer metastasis via EMT inductionFurthermore, pro-death autophagy induction by miRNAs has a negative impact on the viability of tumor cells and decreases their survival rate. The miRNA/autophagy axis functions beyond regulating the growth and invasion of tumor cells, and they can also affect drug resistance and radio-resistance. These subjects are covered in the current review regarding the new updates provided by recent experiments.

17β-estradiol suppresses H2O2-induced senescence in human umbilical vein endothelial cells by inducing autophagy through the PVT1/miR-31/SIRT3 axis

OBJECTIVE

17β-estradiol (17β-E₂) has been implicated in activating autophagy by upregulating SIRT3 (Sirtuin 3) expression, thereby inhibiting the senescence of vascular endothelial cells. Herein, we further examined the molecular mechanisms that regulate SIRT3 expression in 17β-E₂-induced autophagy.

METHODS

Reverse-transcription-polymerase chain reaction was employed to measure the expression of plasmacytoma variant translocation 1 (PVT1), microRNAs (miRNAs), and SIRT3, and the dual-luciferase assay was used to determine their interaction. Electron microscopy observes autophagosomes, green fluorescent protein-microtubule-associated protein 1 light chain 3 (GFP-LC3) staining, and immunoblot analysis with antibodies against LC3，beclin-1, and P62 were conducted to measure autophagy. Cellular senescence was determined using immunoblot analysis with anti-phosphorylated retinoblastoma and senescence-associated β-galactosidase staining.

RESULTS

Women with higher estrogen levels (during the 10-13th day of the menstrual cycle or premenopausal) exhibit markedly higher serum levels of PVT1 than women with lower estrogen levels (during the menstrual period or postmenopausal). The dual-luciferase assay showed that PVT1 acts as a sponge for miR-31, and miR-31 binds to its target gene, SIRT3. The 17β-E₂ treatment increased the expression of PVT1 and SIRT3 and downregulated miR-31 expression in human umbilical vein endothelial cells (HUVECs). Consistently, PVT1 overexpression suppresses miR-31 expression, promotes 17β-E2-induced autophagy, and inhibits H₂O₂-induced senescence. miR-31 inhibitor increases SIRT3 expression and leads to activation of 17β-E₂-induced autophagy and suppression of H₂O₂-induced senescence.

CONCLUSION

Our findings demonstrated that 17β-E₂ upregulates PVT1 gene expression and PVT1 functions as a sponge to inhibit miR-31, resulting in the upregulation of SIRT3 expression and activation of autophagy and subsequent inhibition of H₂O₂-induced senescence in HUVECs.

Identification of Wnt/β-Catenin- and Autophagy-Related lncRNA Signature for Predicting Immune Efficacy in Pancreatic Adenocarcinoma

Pancreatic cancer is one of the tumors with a poor prognosis. Therefore, it is significant and urgent to explore effective biomarkers for risk stratification and prognosis prediction to promote individualized treatment and prolong the survival of patients with PAAD. In this study, we identified Wnt/β-catenin- and autophagy-related long non-coding RNAs (lncRNAs) and demonstrated their role in predicting immune efficacy for PAAD patients. The univariate and multivariate Cox proportional hazards analyses were used to construct a prognostic risk model based on six autophagy- and Wnt/β-catenin-related lncRNAs (warlncRNAs): LINC01347, CASC8, C8orf31, LINC00612, UCA1, and GUSBP11. The high-risk patients were significantly associated with poor overall survival (OS). The receiver operating characteristic (ROC) curve analysis was used to assess the predictive accuracy of the prognostic risk model. The prediction efficiency was supported by the results of an independent validation cohort. Subsequently, a prognostic nomogram combining warlncRNAs with clinical indicators was constructed and showed a good predictive efficiency for survival risk stratification. Furthermore, functional enrichment analysis demonstrated that the signature according to warlncRNAs is closely linked to malignancy-associated immunoregulatory pathways. Correlation analysis uncovered that warlncRNAs' signature was considerably associated with immunocyte infiltration, immune efficacy, tumor microenvironment score, and drug resistance.

Oncogenic lncRNA BBOX1-AS1 promotes PHF8-mediated autophagy and elicits sorafenib resistance in hepatocellular carcinoma

Some long non-coding RNAs (lncRNAs) have been documented to be involved in cancer progression and anticancer drug resistance in hepatocellular carcinoma (HCC). Thus, approaches designed to target these genes may facilitate the development of promising strategies for treating HCC. Previously, we showed that lncRNA BBOX1-AS1 was highly expressed and played an oncogenic role in HCC. However, the potential functions and mechanisms through which BBOX1-AS1 regulates HCC progression and drug resistance remain unclear. This study revealed that BBOX1-AS1 could promote tumor progression, autophagy, and drug resistance by upregulating PHF8 in HCC cells. Mechanistically, BBOX1-AS1 enhanced the stability of PHF8 mRNA by targeting the PHF8 inhibitor miR-361-3p to regulate tumor progression and autophagy in HCC. The functional rescue experiments showed that PHF8 acted as a key factor in regulating the biological effects induced by BBOX1-AS1 and miR-361-3p in HCC, indicating that BBOX1-AS1 promotes tumor progression and sorafenib resistance by regulating miR-361-3p/PHF8. Finally, mouse tumor models and patient-derived organoid models were established to further confirm these findings. Taken together, the results demonstrate that BBOX1-AS1 promotes HCC progression and sorafenib resistance via the miR-361-3p/PHF8 axis.

Molecular subtyping based on TRP family and prognostic assessment for TRP-associated lncRNAs in pancreatic adenocarcinoma

Background

Transient receptor potential (TRP) channels have high permeability to Ca2⁺ ions because they are non-selective ion channels. TRP channels have been implicated in tumor onset and progression, proliferation, and migration in recent years. However, the prognostic value of genes related to TRP and their specific mechanism in pancreatic adenocarcinoma (PAAD) are yet to be understood.

Methods

Public databases such as TCGA and GEO were used to retrieve data on gene expression and clinical information of patients with pancreatic adenocarcinoma for our study. ConsensusClusterPlus package was used for unsupervised clustering analysis. The microenvironment cell population (MCP)-counter approach was employed to measure the immune cells infiltration status. The Pearson correlation was performed to identify TRP-associated lncRNAs.

Results

Initially, we separated PAAD patients into three clusters depending on TRP-related genes, and of the three clusters, cluster B showed the least immune cell infiltration, which was correlated with poor prognosis. Moreover, GSVA enrichment analysis further revealed that cluster A was subjected to a considerable enrichment in carcinogenic signaling pathways, whereas cluster C was enriched in immune-related pathways. Then, using TRP-associated lncRNAs as a starting point, we constructed a prognostic risk model for PAAD patients that could efficiently predict their prognosis. Further, GSEA revealed that cancer-related pathways, for instance, the cell cycle, p53 signaling pathway, etc. were considerably enriched in the high-risk group. In addition, we looked into the link between the prognostic model and the immunological microenvironment. Lower cytotoxic lymphocytes, NK cells, CD8 T cells, and endothelial cells infiltration were found to be associated with high risk using the MCP-counter algorithm. The expression of CD274, POLE2, MCM6, and LOXL2 was also found to be higher in the high-risk group. TMB was also considerably greater in high-risk individuals, indicating that immune checkpoint inhibitors (ICIs) therapy may benefit them more. Lastly, qRT-PCR further confirmed the differential expression of these prognostic TRP-associated lncRNAs, indicating that these lncRNAs play an imperative role in PAAD tumorigenesis.

Conclusion

TRP family genes may represent a new class of candidate molecular markers of the occurrence and progression of PAAD. Risk models based on TRP-associated lncRNAs could provide important new references for immunotargeted therapy of pancreatic adenocarcinoma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02552-y.

lncRNA PVT1: a novel oncogene in multiple cancers

Long noncoding RNAs are involved in epigenetic gene modification, including binding to the chromatin rearrangement complex in pre-transcriptional regulation and to gene promoters in gene expression regulation, as well as acting as microRNA sponges to control messenger RNA levels in post-transcriptional regulation. An increasing number of studies have found that long noncoding RNA plasmacytoma variant translocation 1 (PVT1) plays an important role in cancer development. In this review of a large number of studies on PVT1, we found that PVT1 is closely related to tumor onset, proliferation, invasion, epithelial–mesenchymal transformation, and apoptosis, as well as poor prognosis and radiotherapy and chemotherapy resistance in some cancers. This review comprehensively describes PVT1 expression in various cancers and presents novel approaches to the diagnosis and treatment of cancer.

LncRNA-miRNA axis in tumor progression and therapy response: An emphasis on molecular interactions and therapeutic interventions

Epigenetic factors are critical regulators of biological and pathological mechanisms and they could interact with different molecular pathways. Targeting epigenetic factors has been an idea approach in disease therapy, especially cancer. Accumulating evidence has highlighted function of long non-coding RNAs (lncRNAs) as epigenetic factors in cancer initiation and development and has focused on their association with downstream targets. microRNAs (miRNAs) are the most well-known targets of lncRNAs and present review focuses on lncRNA-miRNA axis in malignancy and therapy resistance of tumors. LncRNA-miRNA regulates cell death mechanisms such as apoptosis and autophagy in cancers. This axis affects tumor metastasis via regulating EMT and MMPs. Besides, lncRNA-miRNA axis determines sensitivity of tumor cells to chemotherapy, radiotherapy and immunotherapy. Based on the studies, lncRNAs can be affected by drugs and genetic tools in cancer therapy and this may affect expression level of miRNAs as their downstream targets, leading to cancer suppression/progression. LncRNAs have both tumor-promoting and tumor-suppressor functions in cancer and this unique function of lncRNAs has complicated their implication in tumor therapy. LncRNA-miRNA axis can also affect other signaling networks in cancer such as PI3K/Akt, STAT3, Wnt/β-catenin and EZH2 among others. Notably, lncRNA/miRNA axis can be considered as a signature for diagnosis and prognosis in cancers.

A novel genomic instability-derived lncRNA signature to predict prognosis and immune characteristics of pancreatic ductal adenocarcinoma

Background

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignant tumor of the digestive system. Its grim prognosis is mainly attributed to the lack of means for early diagnosis and poor response to treatments. Genomic instability is shown to be an important cancer feature and prognostic factor, and its pattern and extent may be associated with poor treatment outcomes in PDAC. Recently, it has been reported that long non-coding RNAs (lncRNAs) play a key role in maintaining genomic instability. However, the identification and clinical significance of genomic instability-related lncRNAs in PDAC have not been fully elucidated.

Methods

Genomic instability-derived lncRNA signature (GILncSig) was constructed based on the results of multiple regression analysis combined with genomic instability-associated lncRNAs and its predictive power was verified by the Kaplan-Meier method. And real-time quantitative polymerase chain reaction (qRT-PCR) was used for simple validation in human cancers and their adjacent non-cancerous tissues. In addition, the correlation between GILncSig and tumor microenvironment (TME) and epithelial-mesenchymal transition (EMT) was investigated by Pearson correlation analysis.

Results

The computational framework identified 206 lncRNAs associated with genomic instability in PDAC and was subsequently used to construct a genome instability-derived five lncRNA-based gene signature. Afterwards, we successfully validated its prognostic capacity in The Cancer Genome Atlas (TCGA) cohort. In addition, via careful examination of the transcriptome expression profile of PDAC patients, we discovered that GILncSig is associated with EMT and an adaptive immunity deficient immune profile within TME.

Conclusions

Our study established a genomic instability-associated lncRNAs-derived model (GILncSig) for prognosis prediction in patients with PDAC, and revealed the potential functional regulatory role of GILncSig.

Knockdown of hsa_circ_0005699 attenuates inflammation and apoptosis induced by ox-LDL in human umbilical vein endothelial cells through regulation of the miR-450b-5p/NFKB1 axis

Atherosclerosis (AS) remains the leading cause of mortality throughout the world, and vascular endothelial cell dysfunction is one of the key events leading to this pathology. In recent years, there has been an increased interest in the role of circulating RNAs in various diseases; these noncoding RNAs can regulate gene products by acting as microRNA (miR) sponges. Furthermore, it has been shown that foam cells exhibit high expression levels of hsa_circ_0005699 (circ_0005699); however, to the best of our knowledge, no previous study has investigated the role of circ_0005699 in the regulation of vascular endothelial function. The present study employed human umbilical vein endothelial cells (HUVECs), which have been widely used to study vascular endothelial cell function. In addition, apolipoprotein E (ApoE)-deficient mice were used, which have been shown to rapidly develop AS and are widely used as a model of this disease. Cellular and biochemical techniques were performed, including gene transfection and short hairpin RNA-mediated gene silencing for cell transfection, luciferase reporter gene assay to confirm predicted genes, Cell Counting Kit-8 assay and flow cytometry to assess cell viability and apoptosis, and reverse transcription-quantitative PCR and western blotting for detection of mRNA and protein expression. In the present study, the expression levels of circ_0005699 were increased by oxidized low-density lipoprotein in a time- and dose-dependent manner in HUVECs; this was also associated with increased apoptosis of these cells. In addition, the expression levels of circ_0005699 were elevated, along with increased levels of inflammatory cytokines, in ApoE-deficient mice. An RNA pull-down assay indicated that circ_0005699 can bind miR-450b-5p to decrease its expression, whereas silencing of circ_0005699 resulted in increased expression of miR-450b-5p. In addition, the online bioinformatics tool starBase predicted NFKB1 as a target gene of miR-450b-5p, which was further confirmed by the luciferase reporter gene assay. Notably, knockdown of circ_0005699 resulted in the increased survival of HUVECs, which was associated with decreased protein expression levels of NFKB1 and inflammatory cytokines. By contrast, the effects of circ-0005699 silencing on survival were reversed by miR-450b-5p inhibition or NFKB1 overexpression. In conclusion, knockdown of circ_0005699 may ameliorate endothelial cell injury through regulation of the miR-450b-5P/NFKB1 signaling axis.

Epigenetic regulation of autophagy in gastrointestinal cancers

The development of novel therapeutic approaches is necessary to manage gastrointestinal cancers (GICs). Considering the effective molecular mechanisms involved in tumor growth, the therapeutic response is pivotal in this process. Autophagy is a highly conserved catabolic process that acts as a double-edged sword in tumorigenesis and tumor inhibition in a context-dependent manner. Depending on the stage of malignancy and cellular origin of the tumor, autophagy might result in cancer cell survival or death during the GICs' progression. Moreover, autophagy can prevent the progression of GIC in the early stages but leads to chemoresistance in advanced stages. Therefore, targeting specific arms of autophagy could be a promising strategy in the prevention of chemoresistance and treatment of GIC. It has been revealed that autophagy is a cytoplasmic event that is subject to transcriptional and epigenetic regulation inside the nucleus. The effect of epigenetic regulation (including DNA methylation, histone modification, and expression of non-coding RNAs (ncRNAs) in cellular fate is still not completely understood. Recent findings have indicated that epigenetic alterations can modify several genes and modulators, eventually leading to inhibition or promotion of autophagy in different cancer stages, and mediating chemoresistance or chemosensitivity. The current review focuses on the links between autophagy and epigenetics in GICs and discusses: 1) How autophagy and epigenetics are linked in GICs, by considering different epigenetic mechanisms; 2) how epigenetics may be involved in the alteration of cancer-related phenotypes, including cell proliferation, invasion, and migration; and 3) how epidrugs modulate autophagy in GICs to overcome chemoresistance.

Emerging roles of long noncoding RNAs in chemoresistance of pancreatic cancer

Pancreatic cancer is one of the most common causes of cancer death in the world due to the lack of early symptoms, metastasis occurrence and chemoresistance. Therefore, early diagnosis by detection of biomarkers, blockade of metastasis, and overcoming chemoresistance are the effective strategies to improve the survival of pancreatic cancer patients. Accumulating evidence has revealed that long noncoding RNA (lncRNA) and circular RNAs (circRNAs) play essential roles in modulating chemosensitivity in pancreatic cancer. In this review article, we will summarize the role of lncRNAs in drug resistance of pancreatic cancer cells, including HOTTIP, HOTAIR, PVT1, linc-ROR, GAS5, UCA1, DYNC2H1-4, MEG3, TUG1, HOST2, HCP5, SLC7A11-AS1 and CASC2. We also highlight the function of circRNAs, such as circHIPK3 and circ_0000284, in regulation of drug sensitivity of pancreatic cancer cells. Moreover, we describe a number of compounds, including curcumin, genistein, resveratrol, quercetin, and salinomycin, which may modulate the expression of lncRNAs and enhance chemosensitivity in pancreatic cancers. Therefore, targeting specific lncRNAs and cicrRNAs could contribute to reverse chemoresistance of pancreatic cancer cells. We hope this review might stimulate the studies of lncRNAs and cicrRNAs, and develop the new therapeutic strategy via modulating these noncoding RNAs to promote chemosensitivity of pancreatic cancer cells.

Function and regulation of ULK1: From physiology to pathology

The expression of ULK1, a core protein of autophagy, is closely related to autophagic activity. Numerous studies have shown that pathological abnormal expression of ULK1 is associated with various human diseases such as neurological disorders, infections, cardiovascular diseases, liver diseases and cancers. In addition, new advances in the regulation of ULK1 have been identified. Furthermore, targeting ULK1 as a therapeutic strategy for diseases is gaining attention as new corresponding activators or inhibitors are being developed. In this review, we describe the structure and regulation of ULK1 as well as the current targeted activators and inhibitors. Moreover, we highlight the pathological disorders of ULK1 expression and its critical role in human diseases.

MiR-152-5p suppresses osteogenic differentiation of mandible mesenchymal stem cells by regulating ATG14-mediated autophagy

BACKGROUND

Osteoporosis affects the mandible resulting in bone loss. Though impairments are not life threatening, they affect a person's quality-of-life particularly vulnerable elderly. MicroRNAs (miRNAs) are novel regulatory factors that play an important role in regulating bone metabolism. Autophagy is evolutionarily conserved intracellular self-degradation process and is vital in the maintenance of both miRNA and bone homeostasis. However, the role of autophagy in the pathogenesis of miRNA regulating osteoporosis remains unclear.

METHODS

In the study, we established a rat osteoporosis model induced by ovariectomy (OVX) and isolated mesenchymal stem cells from mandible (MMSCs-M). Several miRNAs were identified to regulate osteoporosis in some studies. qRT-PCR was applied to examine the expression of miRNA, autophagy and osteogenic differentiation-related genes. Western blotting assays were performed to detect the expression of autophagy and osteogenic differentiation proteins. Immunofluorescence and transmission electron microscope were used to verify the autophagy activity. Transfecting technology was used to enhance or suppress the expression of miR-152-5p which enable us to observe the relationship between miR-152-5p, autophagy and osteogenic differentiation. Additionally, the measurement of reactive oxygen species was used to investigate the mechanism of autophagy affecting osteogenic differentiation.

RESULTS

We found an upregulated expression of miR-152-5p in MMSCs-M in OVX group. Downregulated autophagy-related gene, proteins and autophagosome were detected in vitro of OVX group compared with sham group. Moreover, downregulation of miR-152-5p promoted osteogenic differentiation of MMSCs-M as well as enhanced autophagy-related proteins in OVX group. Conversely, overexpression of miR-152-5p showed opposite effect in sham group. Meanwhile, we found Atg14 (autophagy-related protein homolog 14) was identified to be a direct target of miR-152-5p theoretically and functionally. In other words, we confirmed inhibition of miR-152-5p promoted the osteogenic differentiation via promoting ATG14-mediated autophagy. Furthermore, miR-152-5p/ATG14-mediated autophagy regulated osteogenic differentiation by reducing the endogenous ROS accumulation and maintaining cellular redox homeostasis.

CONCLUSION

Our data suggest that miR-152-5p is the first identified to regulate osteogenic differentiation by directly targeting autophagy-related protein ATG14 and regulating oxidative stress and therapeutic inhibition of miR-152-5p may be an efficient anabolic strategy for osteoporosis.

Effects of TP53 Mutations and miRs on Immune Responses in the Tumor Microenvironment Important in Pancreatic Cancer Progression

Approximately 90% of pancreatic cancers are pancreatic ductal adenocarcinomas (PDAC). PDAC is the fourth leading cause of cancer death world-wide. Therapies for PDAC are largely ineffective due to the dense desmoplastic tumor microenvironment which prevents chemotherapeutic drugs and small molecule inhibitors from exerting effective anti-cancer effects. In this review, we will discuss the roles of TP53 and miRs on the PDAC tumor microenvironment and how loss of the normal functions of TP53 promote tumor progression. The TP53 gene is mutated in approximately 50% of pancreatic cancers. Often, these TP53 mutations are point mutations which confer additional functions for the TP53 proteins. These are called gain of function (GOF) mutations (mut). Another class of TP53 mutations are deletions which result in loss of the TP53 protein; these are referred to TP53-null mutations. We have organized this review into various components/properties of the PDAC microenvironment and how they may be altered in the presence of mutant TP53 and loss of certain miR expression.

ICAM-1-related noncoding RNA accelerates atherosclerosis by amplifying NF-κB signaling

Long noncoding RNAs (lncRNAs) are critical regulators of inflammation with great potential as new therapeutic targets. However, the role of lncRNAs in early atherosclerosis remains poorly characterized. This study aimed to identify the key lncRNA players in activated endothelial cells (ECs). The lncRNAs in response to pro-inflammatory factors in ECs were screened through RNA sequencing. ICAM-1-related non-coding RNA (ICR) was identified as the most potential candidate for early atherosclerosis. ICR is essential for intercellular adhesion molecule-1 (ICAM1) expression, EC adhesion and migration. In a high fat diet-induced atherosclerosis model in mice, ICR is upregulated in the development of atherosclerosis. After intravenous injection of adenovirus carrying shRNA for mouse ICR, the atherosclerotic plaque area was markedly reduced with the declined expression of ICR and ICAM1. Mechanistically, ICR stabilized the mRNA of ICAM1 in quiescent ECs; while under inflammatory stress, ICR upregulated ICAM1 in a nuclear factor kappa B (NF-κB) dependent manner. RNA-seq analysis showed pro-inflammatory targets of NF-κB were regulated by ICR. Furthermore, the chromatin immunoprecipitation assays showed that p65 binds to ICR promoter and facilitates its transcription. Interestingly, ICR, in turn, promotes p65 accumulation and activity, forming a positive feedback loop to amplify NF-κB signaling. Preventing the degradation of p65 using proteasome inhibitors rescued the expression of NF-κB targets suppressed by ICR. Taken together, ICR acts as an accelerator to amplify NF-κB signaling in activated ECs and suppressing ICR is a promising early intervention for atherosclerosis through ICR/p65 loop blockade.

Exosomal long noncoding RNAs - the lead thespian behind the regulation, cause and cure of autophagy-related diseases

Recent advances in exosome biology have revealed significant roles of exosome and their contents in intercellular communication. Among various exosomal content, long non-coding RNAs (lncRNAs), which have a large size (˃ 200 nt) and lack protein coding potential, are known to play key roles in intercellular communication and novel biomarkers of various metabolic disorders. Moreover, long non-coding RNAs are often involved in the regulation of various cellular processes such as autophagy, apoptosis, cell proliferation. On the other hand, autophagy is the central regulating point that controls the various metabolic functions of the body. This process is known to prevent diseases and promote longevity. Therefore, the present review discusses the relationship between diseases and autophagy, and also look into the biological functions of exosome-associated lncRNAs in regulating autophagy. Furthermore, this review will summarize some of the studies that provide novel insights into the pathogenesis of autophagy-related diseases followed by the non-canonical roles played by autophagy and related proteins in the development of exosome biogenesis.

LncRNA LINC01857 drives pancreatic adenocarcinoma progression via modulating miR-19a-3p/SMOC2

OBJECTIVES

Emerging evidence has demonstrated that LINC01857 exerts a pivotal function in many cancers. However, its function in Pancreatic Ductal Adenocarcinoma (PDAC) still remains unclear. This study was designed to investigate the regulatory character of LINC01857 in PDAC.

METHODS

Bioinformatic tools and databases were used to seek potential miRNAs and mRNAs. Gene expression was evaluated by Reverse Transcription quantitative real-time Polymerase Chain Reaction (RT-qPCR), and western blot was used for protein level detection. A subcellular fraction assay was done to ascertain the location of LINC01857 in PANC-1 and BxPC-3 human pancreatic cancer cells. CCK-8, EdU, wound healing and Transwell assays were performed to inquire into the influence of LINC01857, and SPARC -related Modular Calcium-binding protein-2 (SMOC2) on cell viability, proliferation, migration, and invasion, respectively. The interaction between LINC01857 and its downstream genes was explored by RNA immunoprecipitation and luciferase reporter assays.

RESULTS

LINC01857 levels were significantly elevated in PDAC. Knockdown of LINC01857 significantly restrained the proliferation, migration, invasion, and Epithelial-Mesenchymal Transition (EMT) process of PDAC cells. MiR-19a-3p was a downstream target of LINC01857, and miR-19a-3p levels were significantly decreased in PDAC cells. In addition, SMOC2 expression had a negative correlation with that of miR-19a-3p, and SMOC2 was a downstream target of miR-19a-3p. Furthermore, SMOC2 upregulation partially abolished the inhibitive influence of LINC01857 downregulation on cell proliferation, migration, invasion, and the EMT process.

CONCLUSION

LINC01857 promotes malignant phenotypes of PDAC cells via upregulation of SMOC2 by interacting with miR-19a-3p.

Autophagy and beyond: Unraveling the complexity of UNC-51-like kinase 1 (ULK1) from biological functions to therapeutic implications

UNC-51-like kinase 1 (ULK1), as a serine/threonine kinase, is an autophagic initiator in mammals and a homologous protein of autophagy related protein (Atg) 1 in yeast and of UNC-51 in Caenorhabditis elegans. ULK1 is well-known for autophagy activation, which is evolutionarily conserved in protein transport and indispensable to maintain cell homeostasis. As the direct target of energy and nutrition-sensing kinase, ULK1 may contribute to the distribution and utilization of cellular resources in response to metabolism and is closely associated with multiple pathophysiological processes. Moreover, ULK1 has been widely reported to play a crucial role in human diseases, including cancer, neurodegenerative diseases, cardiovascular disease, and infections, and subsequently targeted small-molecule inhibitors or activators are also demonstrated. Interestingly, the non-autophagy function of ULK1 has been emerging, indicating that non-autophagy-relevant ULK1 signaling network is also linked with diseases under some specific contexts. Therefore, in this review, we summarized the structure and functions of ULK1 as an autophagic initiator, with a focus on some new approaches, and further elucidated the key roles of ULK1 in autophagy and non-autophagy. Additionally, we also discussed the relationships between ULK1 and human diseases, as well as illustrated a rapid progress for better understanding of the discovery of more candidate small-molecule drugs targeting ULK1, which will provide a clue on novel ULK1-targeted therapeutics in the future.

HTR1D functions as a key target of HOXA10-AS/miR-340-3p axis to promote the malignant outcome of pancreatic cancer via PI3K-AKT signaling pathway

Competing endogenous RNAs (ceRNAs) are a newly discovered class of molecular regulators involved in many diseases, especially tumors. Therefore, exploration of the potential ceRNA regulatory network regarding the occurrence and development of pancreatic cancer will provide a new theoretical basis for its diagnosis and treatment. Based on the above background, we applied a bioinformatics approach to mine the public database The Cancer Genome Atlas (TCGA) and performed a series of subsequent molecular biology assays to confirm the hypothesis that HOXA10-AS/ miR-340-3p/HTR1D axis could modulate the malignant progression of pancreatic cancer. Here, our present study demonstrated that the expression level of HTR1D, positively correlated with the level of lncRNA HOXA10-AS and negatively associated with the level of miR-340-3p, was significantly increased in pancreatic cancer cell lines (PCs) compared with that in normal HPDE6-C7 cells. Knocking down HTR1D obviously inhibited the proliferation and migration of PCs and promoted apoptosis by upregulating p-AKT. Elevated miR-340-3p blocked the progression of pancreatic cancer by downregulating HTR1D. Lessened level of lncRNA HOXA10-AS reduced the sponging of miR-340-3p, resulting in an increase of miR-340-3p and a subsequent decrease of HTR1D to ultimately suppress the malignant biological behaviors of cancer. These data illustrated that the HOXA10-AS/miR-340-3p/HTR1D ceRNA axis acted a crucial part in the malignant biological behavior of pancreatic cancer in an AKT-dependent manner.

Non-coding RNAs associated with autophagy and their regulatory role in cancer therapeutics

Cancer widely affects the world's health population and ranks second leading cause of death globally. Because of poor prognosis of various types of cancer such as sarcoma, lymphoma, adenomas etc., their high recurrence and metastasis rate and low early diagnosis rate have become concern lately. Role of autophagy in cancer progression is being studied since long. Autophagy is cell's self-degradative mechanism towards stress and has role in degradation of the cytoplasmic macromolecules which has potential to damage other cytosolic molecules. Autophagy can promote as well as inhibit tumorigenesis depending upon the associated protein combinations in cancer cells. Recent studies have shown that non-coding RNAs (ncRNAs) do not code for protein but play essential role in modulation of gene expression. At transcriptional level, different ncRNAs like lncRNAs, miRNAs and circRNAs directly or indirectly affect different stages of autophagy like autophagy-dependent and non-apoptotic cell death in cancer cells. This review focuses on the involvement of ncRNAs in autophagy and the modulation of several cancer signal transduction pathways in cancers such as lung, breast, prostate, pancreatic, thyroid, and kidney cancer.

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.

Long Non-Coding RNAs in Pancreatic Cancer: Biologic Functions, Mechanisms, and Clinical Significance

Despite tremendous efforts devoted to research in pancreatic cancer (PC), the mechanism underlying the tumorigenesis and progression of PC is still not completely clear. Additionally, ideal biomarkers and satisfactory therapeutic strategies for clinical application in PC are still lacking. Accumulating evidence suggests that long non-coding RNAs (lncRNAs) might participate in the pathogenesis of diverse cancers, including PC. The abnormal expression of lncRNAs in PC is considered a vital factor during tumorigenesis that affects tumor cell proliferation, migration, invasion, apoptosis, angiogenesis, and drug resistance. With this review of relevant articles published in recent years, we aimed to summarize the biogenesis mechanism, classifications, and modes of action of lncRNAs and to review the functions and mechanisms of lncRNAs in PC. Additionally, the clinical significance of lncRNAs in PC was discussed. Finally, we pointed out the questions remaining from recent studies and anticipated that further investigations would address these gaps in knowledge in this field.

Oxidative Stress and Inflammation in Cardiovascular Diseases and Cancer: Role of Non-coding RNAs

High oxidative stress, Th1/Th17 immune response, M1 macrophage inflammation, and cell death are associated with cardiovascular diseases. Controlled oxidative stress, Th2/Treg anti-tumor immune response, M2 macrophage inflammation, and survival are associated with cancer. MiR-21 protects against cardiovascular diseases but may induce tumor growth by retaining the anti-inflammatory M2 macrophage and Treg phenotypes and inhibiting apoptosis. Down-regulation of let-7, miR-1, miR-9, miR-16, miR-20a, miR-22a, miR-23a, miR-24a, miR-26a, miR-29, miR-30a, miR-34a, miR-124, miR-128, miR-130a, miR-133, miR-140, miR-143-145, miR-150, miR-153, miR-181a, miR-378, and miR-383 may aid cancer cells to escape from stresses. Upregulation of miR-146 and miR-223 may reduce anti-tumor immune response together with miR-21 that also protects against apoptosis. MiR-155 and silencing of let-7e, miR-125, and miR-126 increase anti-tumor immune response. MiR expression depends on oxidative stress, cytokines, MYC, and TGF-β, and expression of silencing lncRNAs and circ-RNAs. However, one lncRNA or circ-RNA may have opposite effects by targeting several miRs. For example, PVT1 induces apoptosis by targeting miR-16a and miR-30a but inhibits apoptosis by silencing miR-17. In addition, levels of a non-coding RNA in a cell type depend not only on expression in that cell type but also on an exchange of microvesicles between cell types and tumors. Although we got more insight into the function of a growing number of individual non-coding RNAs, overall, we do not know enough how several of them interact in functional networks and how their expression changes at different stages of disease progression.

Hypoxia-induced PVT1 promotes lung cancer chemoresistance to cisplatin by autophagy via PVT1/miR-140-3p/ATG5 axis

Lung cancer is one of the most common and lethal malignant tumors and the cases increased rapidly. Elevated chemoresistance during chemotherapy resistance remains a challenge. Hypoxia is one of the components that lead to chemoresistance. PVT1 participates in various tumor drug resistance and is associated with hypoxia conditions. The present study aimed to analyze the regulatory relationship of hypoxia and PVT1 and the mechanism of PVT1 in the hypoxia-induced chemoresistance process of lung cancer. The expression of PVT1 in lung cancer and adjacent tissues, and cell lines were analyzed using the TCGA database and qPCR. The regulatory relationship between hypoxia and PVT1 was validated and analyzed with qPCR, luciferase reporter system, and CHIP-qPCR. The role of PVT1 in chemoresistance ability induced by hypoxia was analyzed with CCK-8 assay and flow cytometry. The roles of PVT1, hypoxia, and chemoresistance were also analyzed with LC3-GFP transfection, WB, and IHC. Finally, the results were further validated in xenograft models. PVT1 is highly expressed in lung cancer and cell lines, and the expression of PVT1 is regulated by HIF-1α, and the luciferase reporter assay and CHIP-qPCR analysis indicated that HIF-1α could bind to the promoter region of PVT1 and regulate PVT1 expression. PVT1 participated in hypoxia-induced chemoresistance and induced higher viability and lower apoptosis rate by the autophagy signaling pathway via PVT1/miR-140-3p/ATG5 axis. All the findings were validated in the xenograft models. In conclusion, these results suggest that the expression of PVT1 is regulated by HIF-1α and participates in hypoxia-induced chemoresistance.

LncRNA Uc003xsl.1-Mediated Activation of the NFκB/IL8 Axis Promotes Progression of Triple-Negative Breast Cancer

Aberrant activation of NFκB orchestrates a critical role in tumor carcinogenesis; however, the regulatory mechanisms underlying this activation are not fully understood. Here we report that a novel long noncoding RNA (lncRNA) Uc003xsl.1 is highly expressed in triple-negative breast cancer (TNBC) and correlates with poor outcomes in patients with TNBC. Uc003xsl.1 directly bound nuclear transcriptional factor NFκB-repressing factor (NKRF), subsequently preventing NKRF from binding to a specific negative regulatory element in the promoter of the NFκB-responsive gene IL8 and abolishing the negative regulation of NKRF on NFκB-mediated transcription of IL8. Activation of the NFκB/IL8 axis promoted the progression of TNBC. Trop2-based antibody-drug conjugates have been applied in clinical trials in TNBC. In this study, a Trop2-targeting, redox-responsive nanoparticle was developed to systematically deliver Uc003xsl.1 siRNA to TNBC cells in vivo, which reduced Uc003xsl.1 expression and suppressed TNBC tumor growth and metastasis. Therefore, targeting Uc003xsl.1 to suppress the NFκB/IL8 axis represents a promising therapeutic strategy for TNBC treatment.

SIGNIFICANCE

These findings identify an epigenetic-driven NFκB/IL8 cascade initiated by a lncRNA, whose aberrant activation contributes to tumor metastasis and poor survival in patients with triple-negative breast cancer.

Optimization of endothelial growth factor receptor monoclonal antibody-gold nanorods photothermal therapy for laryngeal squamous cell carcinoma

It reported that heat generated by near-infrared laser irradiation of gold nanorods (AuNRs) effectively inhibited tumor cells, and the conjugate of epidermal growth factor receptor monoclonal antibody (EGFRmAb) and gold nanorods could selectively binded to the surface of cancer cell membrane expressing EGFR. However, there are few research reports on EGFRmAb-AuNRs in laryngeal squamous cell carcinoma. Therefore, our study aimed to investigate the photothermal effect of EGFRmAb modified AuNRs in inducing tumor cell death in an animal model of laryngeal squamous cell carcinoma. We showed that the conjugates of EGFRmAb and AuNRs selectively entered laryngeal squamous cell carcinoma cells. We analyzed the parameters of laser irradiation by controlling the near-infrared to optimize the condition and procedure of targeted treatment in nude mice treated with EGFRmAb and AuNRs. In addition, we examined the safety of the combined therapy. Test results showed that EGFRmAb-AuNRs inhibited the growth of Hep-2 and CNE-2 cells but not normal epithelial cells, and the semi-inhibitor concentration of EGFRmAb in Hep-2 and CNE-2 cells was 4 pmol/ml and 2 pmol/ml, respectively. AuNRs injected into the tumor and irradiated by near-infrared laser effectively inhibited tumor growth in nude mice without toxic effect in mice. We further confirmed that the apoptosis and necrosis rates of tumor cells in mice were highest under 3 W/cm² near-infrared laser irradiation and AuNRs minimum concentration of 280 μg/kg. In conclusion, we developed a new method of targeting EGFRmAb combined with AuNRs to achieve photothermal effect in the treatment of laryngeal squamous cell carcinoma.

The new horizon of biomarker in melanoma patients: A study based on autophagy-related long non-coding RNA

Autophagy-related long non-coding RNAs (arlncRNAs) play a crucial role in the pathogenesis and development of the tumor. However, there is a lack of systematic analysis of arlncRNAs in melanoma patients.Melanoma data for analysis were obtained from The Cancer Genome Atlas (TCGA) database. By establishing a co-expression network of autophagy-related mRNAs-lncRNAs, we identified arlncRNAs in melanoma patients. We evaluated the prognostic value of arlncRNAs by univariate and multivariate Cox analysis and constructed an arlncRNAs risk model. Patients were divided into high- and low-risk groups based on the arlncRNAs risk score. This model was evaluated by Kaplan-Meier (K-M) analysis, univariate-multivariate Cox regression analysis, and receiver operating characteristic (ROC) curve analysis. Characteristics of autophagy genes and co-expressive tendency were analyzed by principal component analysis and Gene Set Enrichment Analysis (GSEA) functional annotation.Nine arlncRNAs (USP30-AS1, LINC00665, PCED1B-AS1, LINC00324, LINC01871, ZEB1-AS1, LINC01527, AC018553.1, and HLA-DQB1-AS1) were identified to be related to the prognosis of melanoma patients. Otherwise, the 9 arlncRNAs constituted an arlncRNAs prognostic risk model. K-M analysis and ROC curve analysis showed that the arlncRNAs risk model has good discrimination. Univariate and multivariate Cox regression analysis showed that arlncRNAs risk model was an independent prognostic factor in melanoma patients. Principal component analysis and GSEA functional annotation showed different autophagy and carcinogenic status in the high- and low-risk groups.This novel arlncRNAs risk model plays an essential role in predicting of the prognosis of melanoma patients. The model reveals new prognosis-related biomarkers for autophagy, promotes precision medicine, and provides a lurking target for melanoma's autophagy-related treatment.

MicroRNA-20a-5p Inhibits the Autophagy and Cisplatin Resistance in Ovarian Cancer via Regulating DNMT3B-mediated DNA Methylation of RBP1

Ovarian cancer (OvCa) is the third most common female malignancy worldwide and poses great threats on women health. Chemotherapy is the most recommended post-surgery treatment for OvCa patients; but, cisplatin resistance is a main cause of chemotherapy failure. In addition, autophagy modulates the sensitivity of tumor cells to chemotherapeutic agents. Hence, it is significant to explore the molecular mechanism concerning the autophagy and cisplatin resistance in OvCa. In this study, quantitative real-time PCR (qRT-PCR) was used to detect miR-20a-5p expression and western blot to measure RBP1 expression. A series of assays were conducted to explore the gain-of-function effects of miR-20a-5p. Luciferase reporter assay was applied to determine the downstream target of miR-20a-5p. The results proved that miR-20a-5p represses malignant phenotypes and autophagy in cisplatin-resistant OvCa cells. In addition, DNMT3B mediates DNA methylation of RBP1 to impair the promoting effects of RBP1 on carcinogenesis and autophagy in OvCa. Through rescue experiments, we certified that miR-20a-5p inhibits the autophagy and cisplatin resistance in OvCa via DNMT3B-mediated DNA methylation of RBP1. Collectively, we demonstrated that miR-20a-5p plays a crucial role in the modulation of autophagy and cisplatin resistance in OvCa, which might offer novel insights into developing effective treatment strategies for OvCa.

Non-coding RNAs as new autophagy regulators in cancer progression

Recent advances highlight that non-coding RNAs (ncRNAs) are emerging as fundamental regulators in various physiological as well as pathological processes by regulating macro-autophagy. Studies have disclosed that macro-autophagy, which is a highly conserved process involving cellular nutrients, components, and recycling of organelles, can be either selective or non-selective and ncRNAs show their regulation on selective autophagy as well as non-selective autophagy. The abnormal expression of ncRNAs will result in the impairment of autophagy and contribute to carcinogenesis and cancer progression by regulating both selective autophagy as well as non-selective autophagy. This review focuses on the regulatory roles of ncRNAs in autophagy and their involvement in cancer which may provide valuable therapeutic targets for cancer management.

Parkinson's Disease Is Associated With Dysregulation of Circulatory Levels of lncRNAs

Long non-coding RNAs (lncRNAs) have been recently reported to be involved in the pathoetiology of Parkinson’s disease (PD). Circulatory levels of lncRNAs might be used as markers for PD. In the present work, we measured expression levels of HULC, PVT1, MEG3, SPRY4-IT1, LINC-ROR and DSCAM-AS1 lncRNAs in the circulation of patients with PD versus healthy controls. Expression of HULC was lower in total patients compared with total controls (Expression ratio (ER)=0.19, adjusted P value<0.0001) as well as in female patients compared with female controls (ER=0.071, adjusted P value=0.0004). Expression of PVT1 was lower in total patients compared with total controls (ER=0.55, adjusted P value=0.0124). Expression of DSCAM-AS1 was higher in total patients compared with total controls (ER=5.67, P value=0.0029) and in male patients compared with male controls (ER=9.526, adjusted P value=0.0024). Expression of SPRY4-IT was higher in total patients compared with total controls (ER=2.64, adjusted P value<0.02) and in male patients compared with male controls (ER=3.43, P value<0.03). Expression of LINC-ROR was higher in total patients compared with total controls (ER=10.36, adjusted P value<0.0001) and in both male and female patients compared with sex-matched controls (ER=4.57, adjusted P value=0.03 and ER=23.47, adjusted P value=0.0019, respectively). Finally, expression of MEG3 was higher in total patients compared with total controls (ER=13.94, adjusted P value<0.0001) and in both male and female patients compared with sex-matched controls (ER=8.60, adjusted P value<0.004 and ER=22.58, adjusted P value<0.0085, respectively). ROC curve analysis revealed that MEG3 and LINC-ROR have diagnostic power of 0.77 and 0.73, respectively. Other lncRNAs had AUC values less than 0.7. Expression of none of lncRNAs was correlated with age of patients, disease duration, disease stage, MMSE or UPDRS. The current study provides further evidence for dysregulation of lncRNAs in the circulation of PD patients.

PAX5-activated lncRNA ARRDC1-AS1 accelerates the autophagy and progression of DLBCL through sponging miR-2355-5p to regulate ATG5

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) has high cancer-related mortality. Studies have supported that lncRNAs can regulate cancer progression by affecting autophagy of cells. ARRDC1 antisense RNA 1 (ARRDC1-AS1) was found to be upregulated in DLBCL tissues in GEPIA, but it has never been detected in DLBCL.

AIM

In this study, we aimed to explore the regulatory mechanism of ARRDC1-AS1 in DLBCL cells.

MAIN METHODS

RT-qPCR was taken to measure the expression of ARRDC1-AS1, microRNA-2355-5p (miR-2355-5p) and autophagy-related gene 5 (ATG5) in DLBCL cells. Western blot was conducted to detect protein levels. The malignant behaviors of DLBCL cells were estimated through functional assays. The molecular interactions were detected by Chromatin immunoprecipitation (ChIP), RNA pull-down, RNA immunoprecipitation (RIP) and luciferase reporter assays.

RESULTS

We found that ARRDC1-AS1 was upregulated in DLBCL tissues and cell lines. ARRDC1-AS1 was activated by transcription factor PAX5. Knockdown of ARRDC1-AS1 suppressed DLBCL autophagy to aggravate proliferation, repress apoptosis, and facilitate invasion and migration. Furthermore, ARRDC1-AS1 sponged miR-2355-5p to upregulate ATG5.

CONCLUSION

Present study first showed that PAX5-activated ARRDC1-AS1 accelerates the autophagy and progression of DLBCL via sponging miR-2355-5p to regulate ATG5, revealing a novel molecular mechanism of ARRDC1-AS1 in DLBCL and suggested ARRDC1-AS1 as a potential target in DLBCL.

Long intergenic non-protein coding RNA 960 regulates cancer cell viability, migration and invasion through modulating miR-146a-5p/interleukin 1 receptor associated kinase 1 axis in pancreatic ductal adenocarcinoma

Long non-coding RNAs (lncRNAs) are considered as crucial regulatory factors in cancer biology. However, the biological function of long intergenic non-protein coding RNA 960 (LINC00960) in the tumorigenesis of pancreatic ductal adenocarcinoma (PDAC) is still unknown. The goal of this study is to investigate the role of LINC00960 in PDAC. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to examine the expression levels of LINC00960 in PDAC tissues and cell lines. After transfection, the loss-of-function models of LINC00960 or interleukin 1 receptor-associated kinase 1 (IRAK1) were established with BxPC-3 cells and Colo357 cells, and the malignant phenotypes of BxPC-3 cells and Colo357 cells were detected by CCK-8 assay, BrdU assay and Transwell assay, respectively. The interactions among LINC00960, miR-146a-5p and IRAK1 were predicted by bioinformatics analysis, and verified by luciferase reporter assay, RNA immunoprecipitation assay and RNA pull-down assay. The regulatory functions of LINC00960 and miR-146a-5p on IRAK1 were detected by Western blot. We demonstrated that the LINC00960 expression was increased in PDAC tissues and cell lines. Knocking down LINC00960 or IRAK1 could repress the viability, migration, and invasion of BxPC-3 and Colo357 cells. LINC00960 functioned as a molecular sponge for miR-146a-5p, and IRAK1 was verified as a target gene of miR-146a-5p. Additionally, LINC00960 could up-regulate IRAK1 expression via repressing miR-146a-5p, and the oncogenic properties of LINC00960 were partly reversed by miR-146a-5p. Our findings reveal that LINC00960 is a promoter of PDAC progression through regulating miR-146a-5p/IRAK1axis.

Autophagy and gastrointestinal cancers: the behind the scenes role of long non-coding RNAs in initiation, progression, and treatment resistance

Gastrointestinal (GI) cancers comprise a heterogeneous group of complex disorders that affect different organs, including esophagus, stomach, gallbladder, liver, biliary tract, pancreas, small intestine, colon, rectum, and anus. Recently, an explosion in nucleic acid-based technologies has led to the discovery of long non-coding RNAs (lncRNAs) that have been found to possess unique regulatory functions. This class of RNAs is >200 nucleotides in length, and is characterized by their lack of protein coding. LncRNAs exert regulatory effects in GI cancer development by affecting different functions such as the proliferation and metastasis of cancer cells, apoptosis, glycolysis and angiogenesis. Over the past few decades, considerable evidence has revealed the important role of autophagy in both GI cancer progression and suppression. In addition, recent studies have confirmed a significant correlation between lncRNAs and the regulation of autophagy. In this review, we summarize how lncRNAs play a behind the scenes role in the pathogenesis of GI cancers through regulation of autophagy.

Long Non-Coding RNAs in Epithelial-Mesenchymal Transition of Pancreatic Cancer

Non-coding RNAs (ncRNAs), or RNA molecules that do not code for proteins, are generally categorized as either small or long ncRNA (lncRNA) and are involved in the pathogenesis of several diseases including many cancers. Identification of a large number of ncRNAs could help to elucidate previously unknown mechanisms in phenotype regulation. Some ncRNAs are encapsulated by extracellular vesicles (EVs) and transferred to recipient cells to regulate cellular processes, including epigenetic and post-transcriptional regulations. Recent studies have uncovered novel molecular mechanisms and functions of lncRNAs in pancreatic ductal adenocarcinoma (PDAC), one of the most intractable cancers that is highly invasive and metastatic. As the epithelial-mesenchymal transition (EMT) triggers tumor cell invasion and migration, clarification of the roles of lncRNA in EMT and tumor cell stemness would be critical for improving diagnostic and therapeutic approaches in metastatic cancers. This review provides an overview of relevant studies on lncRNA and its involvement with EMT in PDAC. Emerging knowledge offers evidence for the dysregulated expression of lncRNAs and essential insights into the potential contribution of both lncRNAs and EVs in the pathogenesis of PDAC. Future directions and new clinical applications for PDAC are also discussed.

Long non-coding RNA LINC01559 exerts oncogenic role via enhancing autophagy in lung adenocarcinoma

BACKGROUND

Long non-coding RNAs (lncRNAs) have been verified to play fatal role in regulating the progression of lung adenocarcinoma (LUAD). Although lncRNAs play important role in regulating the autophagy of tumor cells, the function and molecular mechanism of LINC01559 in regulating lung cancer development remain to be elucidated.

METHOD AND MATERIALS

In this study, we used bioinformatics to screen out autophagy-related lncRNAs from TCGA-LUAD repository. Then the least absolute shrinkage and selection operator (LASSO) regression was applied to establish the signature of autophagy-related lncRNAs so that clinical characteristics and survival in LUAD patients be evaluated. Finally, we selected the most significant differences lncRNA, LINC01559, to verify its function in regulating LUAD progression in vitro.

RESULTS

We found high expression of LINC01559 indicates lymph node metastasis and poor prognosis. Besides, LINC01559 promotes lung cancer cell proliferation and migration in vitro, by enhancing autophagy signal pathway via sponging hsa-miR-1343-3p.

CONCLUSION

We revealed a novel prognostic model based on autophagy-related lncRNAs, and provide a new therapeutic target and for patients with lung adenocarcinoma named LINC01559.

CircMYOF triggers progression and facilitates glycolysis via the VEGFA/PI3K/AKT axis by absorbing miR-4739 in pancreatic ductal adenocarcinoma

Emerging evidence has demonstrated that circular RNAs (circRNAs) take part in the initiation and development of pancreatic ductal adenocarcinoma (PDA), a deadly neoplasm with an extremely low 5-year survival rate. Reprogrammed glucose metabolism is a key feature of tumour development, including PDA. In this research, we evaluated the role of circRNAs in reprogrammed glucose metabolism in PDA. RNA sequencing under various glucose incubation circumstances was performed. A new circMYOF was identified. Sanger sequencing and RNase R treatment confirmed its circular RNA characteristics. Real-time PCR indicated that it was highly expressed in PDA clinical specimens and cell lines. Gain-of- and loss-of-function assays showed that circMYOF induced progression in PDA. Mechanistically, RNA pull-down and luciferase reporter experiments elucidated that circMYOF, as a competing endogenous RNA for miR-4739, facilitated glycolysis via the VEGFA/PI3K/AKT pathway. Taken together, our findings indicate that circMYOF may work as a desirable biomarker and therapeutic target for PDA patients.

Long noncoding RNA SNHG6 promotes oesophageal squamous cell carcinoma by downregulating the miR-101-3p/EZH2 pathway

Long noncoding RNAs (LncRNAs) have been reported to play a vital role in the development of oesophageal squamous cell carcinoma (OSCC). Our previous study revealed that the significant upregulation of the LncRNA small nucleolar RNA host gene 6 (SNHG6) in OSCC promotes OSCC tumourigenesis. However, the mechanisms underlying the dynamics of SNHG6 expression in OSCC have rarely been studied. In this study, we verified the tumour-promoting effect of SNHG6 through sponging miR-101-3p, and their levels were negatively correlated in human samples of OSCC. In addition, miR-101-3p overexpression reversed the effect of SNHG6. Moreover, we confirmed that SNHG6/miR-101-3p affects OSCC by regulating the expression of the enhancer of zeste 2 (EZH2). The effect of EZH2 silencing resembled closely that of SNHG6 knockdown. EZH2 silencing inhibited the expression of protein cyclin D1 and β-catenin, but in contrast, it enhanced the expression of E-cadherin. These findings demonstrated the oncogenic role of SNHG6, which promotes OSCC progression by regulating the expression of EZH2 through its interaction with miR-101-3p. These findings may help in improving the diagnosis and treatment methods of OSCC.

Long Noncoding Competing Endogenous RNA Networks in Pancreatic Cancer

Pancreatic cancer (PC) is a highly malignant disease characterized by insidious onset, rapid progress, and poor therapeutic effects. The molecular mechanisms associated with PC initiation and progression are largely insufficient, hampering the exploitation of novel diagnostic biomarkers and development of efficient therapeutic strategies. Emerging evidence recently reveals that noncoding RNAs (ncRNAs), including long ncRNAs (lncRNAs) and microRNAs (miRNAs), extensively participate in PC pathogenesis. Specifically, lncRNAs can function as competing endogenous RNAs (ceRNAs), competitively sequestering miRNAs, therefore modulating the expression levels of their downstream target genes. Such complex lncRNA/miRNA/mRNA networks, namely, ceRNA networks, play crucial roles in the biological processes of PC by regulating cell growth and survival, epithelial-mesenchymal transition and metastasis, cancer stem cell maintenance, metabolism, autophagy, chemoresistance, and angiogenesis. In this review, the emerging knowledge on the lncRNA-associated ceRNA networks involved in PC initiation and progression will be summarized, and the potentials of the competitive crosstalk as diagnostic, prognostic, and therapeutic targets will be comprehensively discussed.

PURPL represses autophagic cell death to promote cutaneous melanoma by modulating ULK1 phosphorylation

Uncontrolled overactivation of autophagy may lead to autophagic cell death, suppression of which is a pro-survival strategy for tumors. However, mechanisms involving key regulators in modulating autophagic cell death remain poorly defined. Here, we report a novel long noncoding RNA, p53 upregulated regulator of p53 levels (PURPL), functions as an oncogene to promote cell proliferation, colony formation, migration, invasiveness, and inhibits cell death in melanoma cells. Mechanistic studies showed that PURPL promoted mTOR-mediated ULK1 phosphorylation at Ser757 by physical interacting with mTOR and ULK1 to constrain autophagic response to avoid cell death. Loss of PURPL led to AMPK-mediated phosphorylation of ULK1 at Ser555 and Ser317 to over-activate autophagy and induce autophagic cell death. Our results identify PURPL as a key regulator to modulate the activity of autophagy initiation factor ULK1 to repress autophagic cell death in melanoma and may represent a potential intervention target for melanoma therapy.

Regulation and function of autophagy in pancreatic cancer

Oncogenic KRAS mutation-driven pancreatic ductal adenocarcinoma is currently the fourth-leading cause of cancer-related deaths in the United States. Macroautophagy (hereafter "autophagy") is one of the lysosome-dependent degradation systems that can remove abnormal proteins, damaged organelles, or invading pathogens by activating dynamic membrane structures (e.g., phagophores, autophagosomes, and autolysosomes). Impaired autophagy (including excessive activation and defects) is a pathological feature of human diseases, including pancreatic cancer. However, dysfunctional autophagy has many types and plays a complex role in pancreatic tumor biology, depending on various factors, such as tumor stage, microenvironment, immunometabolic state, and death signals. As a modulator connecting various cellular events, pharmacological targeting of nonselective autophagy may lead to both good and bad therapeutic effects. In contrast, targeting selective autophagy could reduce potential side effects of the drugs used. In this review, we describe the advances and challenges of autophagy in the development and therapy of pancreatic cancer.Abbreviations: AMPK: AMP-activated protein kinase; CQ: chloroquine; csc: cancer stem cells; DAMP: danger/damage-associated molecular pattern; EMT: epithelial-mesenchymal transition; lncRNA: long noncoding RNA; MIR: microRNA; PanIN: pancreatic intraepithelial neoplasia; PDAC: pancreatic ductal adenocarcinoma; PtdIns3K: phosphatidylinositol 3-kinase; SNARE: soluble NSF attachment protein receptor; UPS: ubiquitin-proteasome system.

Non-coding RNA-mediated autophagy in cancer: A protumor or antitumor factor?

Autophagy, usually referred to as macroautophagy, is a cytoprotective behavior that helps cells, especially cancer cells, escape crises. However, the role of autophagy in cancer remains controversial. The induction of autophagy is favorable for tumor growth, as it can degrade damaged cell components accumulated during nutrient deficiency, chemotherapy, or other stresses in a timely manner. Whereas the antitumor effect of autophagy might be closely related to its crosstalk with metabolism, immunomodulation, and other pathways. Recent studies have verified that lncRNAs and circRNAs modulate autophagy in carcinogenesis, cancer cells proliferation, apoptosis, metastasis, and chemoresistance via multiple mechanisms. A comprehensive understanding of the regulatory relationships between ncRNAs and autophagy in cancer might resolve chemoresistance and also offer intervention strategies for cancer therapy. This review systematically displays the regulatory effects of lncRNAs and circRNAs on autophagy in the contexts of cancer initiation, progression, and resistance to chemo- or radiotherapy and provides a novel insight into cancer therapy.

Positive feedback between lncRNA FLVCR1-AS1 and KLF10 may inhibit pancreatic cancer progression via the PTEN/AKT pathway

BACKGROUND

FLVCR1-AS1 is a key regulator of cancer progression. However, the biological functions and underlying molecular mechanisms of pancreatic cancer (PC) remain unknown.

METHODS

FLVCR1-AS1 expression levels in 77 PC tissues and matched non-tumor tissues were analyzed by qRT-PCR. Moreover, the role of FLVCR1-AS1 in PC cell proliferation, cell cycle, and migration was verified via functional in vitro and in vivo experiments. Further, the potential competitive endogenous RNA (ceRNA) network between FLVCR1-AS1 and KLF10, as well as FLVCR1-AS1 transcription levels, were investigated.

RESULTS

FLVCR1-AS1 expression was low in both PC tissues and PC cell lines, and FLVCR1-AS1 downregulation was associated with a worse prognosis in patients with PC. Functional experiments demonstrated that FLVCR1-AS1 overexpression significantly suppressed PC cell proliferation, cell cycle, and migration both in vitro and in vivo. Mechanistic investigations revealed that FLVCR1-AS1 acts as a ceRNA to sequester miR-513c-5p or miR-514b-5p from the sponging KLF10 mRNA, thereby relieving their suppressive effects on KLF10 expression. Additionally, FLVCR1-AS1 was shown to be a direct transcriptional target of KLF10.

CONCLUSIONS

Our research suggests that FLVCR1-AS1 plays a tumor-suppressive role in PC by inhibiting proliferation, cell cycle, and migration through a positive feedback loop with KLF10, thereby providing a novel therapeutic strategy for PC treatment.

Myricetin ameliorates ox-LDL-induced HUVECs apoptosis and inflammation via lncRNA GAS5 upregulating the expression of miR-29a-3p

Oxidized low-density lipoprotein (ox-LDL)-induced endothelial cell dysfunction is a significant event in the progression of atherosclerosis. Even Myricetin (Myr) has been exhibited strong antioxidant potency, the effect on atherosclerosis is still elusive. HUVECs were subjected to ox-LDL, before which cells were preconditioned with Myr. Cell Counting Kit-8 assay, flow cytometry, quantitative real-time polymerase chain reaction and Western blot were carried out to assess the impacts of ox-LDL and Myr on HUVECs. The expression of EndMT markers was determined by Western blot analysis and immunocytochemistry. In addition, the relationship of GAS5 and miR-29a-3p was evaluated by RNA Fluorescent in Situ Hybridization and RNA immunoprecipitation assay. Myr preconditioning prevented ox-LDL-induced apoptosis, inflammatory response, and EndMT. GAS5 was upregulated in response to ox-LDL while it was down-regulated by Myr preconditioning. GAS5 over-expression attenuates Myr protective effects against ox-LDL–mediated HUVEC injury. Besides, miR-29a-3p is a target of GAS5 and down-regulated miR-29a-3p could further reduce the effects of GAS5 in ox-LDL–mediated HUVEC. Furthermore, Myr inactivated the TLR4/NF-κB signalling pathway in ox-LDL-treated HUVEC by down-regulating GAS5 or upregulating miR-26a-5p. Myr possessed an anti-inflammatory and anti-EndMT function against ox-LDL-induced HUVEC injury by regulating the GAS5/miR-29a-3p, indicating that Myr may have an important therapeutic function for atherosclerosis.

The Nucleus/Mitochondria-Shuttling LncRNAs Function as New Epigenetic Regulators of Mitophagy in Cancer

Mitophagy is a specialized autophagic pathway responsible for the selective removal of damaged or dysfunctional mitochondria by targeting them to the autophagosome in order to maintain mitochondria quality. The role of mitophagy in tumorigenesis has been conflicting, with the process both supporting tumor cell survival and promoting cell death. Cancer cells may utilize the mitophagy pathway to augment their metabolic requirements and resistance to cell death, thereby leading to increased cell proliferation and invasiveness. This review highlights major regulatory pathways of mitophagy involved in cancer. In particular, we summarize recent progress regarding how nuclear-encoded long non-coding RNAs (lncRNAs) function as novel epigenetic players in the mitochondria of cancer cells, affecting the malignant behavior of tumors by regulating mitophagy. Finally, we discuss the potential application of regulating mitophagy as a new target for cancer therapy.

Ferroptosis-related lncRNA pairs to predict the clinical outcome and molecular characteristics of pancreatic ductal adenocarcinoma

Ferroptosis is a form of regulated cell death initiated by oxidative perturbations that can be blocked by iron chelators and lipophilic antioxidants, and ferroptosis may be the silver bullet treatment for multiple cancers, including immunotherapy- and chemotherapy-insensitive cancers such as pancreatic ductal adenocarcinoma (PDAC). Numerous studies have noted that long non-coding RNAs (lncRNAs) regulate the biological behaviour of cancer cells by binding to DNA, RNA and protein. However, few studies have reported the role of lncRNAs in ferroptosis processes and the function of ferroptosis-associated lncRNAs. The primary objective of the present study was to identify ferroptosis-related lncRNAs using bioinformatic approaches combined with experimental validation. The second objective was to construct a prognostic model to predict the overall survival of patients with PDAC. The present study identified ferroptosis-related lncRNAs using a bioinformatic approach and validated them in an independent pancreatic cancer cohort from Fudan University Shanghai Cancer Center. The lncRNA SLCO4A1-AS1 was identified as a novel molecule mediating ferroptosis resistance in vitro. A novel algorithm was used to construct a '0 or 1' matrix-based prognosis model, which showed promising diagnostic accuracy for potential clinical translation (area under the curve = 0.89 for the 2-year survival rate). Notably, molecular subtypes classified by the risk scores of the model did not belong to any previously reported subtypes of PDAC. The immune microenvironment, metabolic activities, mutation landscape and ferroptosis sensitivity were significantly distinct between patients with different risk scores. Sensitivity (IC50) to 30 common anticancer drugs was analysed between patients with different risks, and imatinib and axitinib were found to be potential drugs for the treatment of patients with lower risk scores. Overall, we developed an accurate prognostic model based on the expression patterns of ferroptosis lncRNAs, which may contribute greatly to the evaluation of patient prognosis, molecular characteristics and treatment modalities and could be further translated into clinical applications.

Autophagy-Related Genes and Long Noncoding RNAs Signatures as Predictive Biomarkers for Osteosarcoma Survival

Osteosarcoma is a common malignant tumor that seriously threatens the lives of teenagers and children. Autophagy is an intracellular metabolic process mediated by autophagy-related genes (ARGs), which is known to be associated with the progression and drug resistance of osteosarcoma. In this study, RNA sequence data from TARGET and genotype-tissue expression (GTEx) databases were analyzed. A six autophagy-related long noncoding RNAs (ARLs) signature that accurately predicted the clinical outcomes of osteosarcoma patients was identified, and the relations between immune response and the ARLs prognostic signature were examined. In addition, we obtained 30 ARGs differentially expressed among osteosarcoma tissue and healthy tissue, and performed functional enrichment analysis on them. To screen for prognostic-related ARGs, univariate and LASSO Cox regression analyses were successively applied. Then, multivariate regression analysis was used to complete construction of the prognostic signature of ARGs. Based on the risk coefficient, we calculated the risk score and grouped the patients. Survival analysis showed that high-risk patients evolve with poor prognosis. And we verified the prognosis model in the GSE21257 cohort. Finally, verification was conducted by qRT-PCR and western blot to measure the expression of genes. The results show that autophagy-related marker models may provide a new therapeutic and diagnostic target for osteosarcoma.

LncRNA ZNFTR functions as an inhibitor in pancreatic cancer by modulating ATF3/ZNF24/VEGFA pathway

The majority of long non-coding RNAs (lncRNAs) have been discovered to be overexpressed in pancreatic cancer (PC) and served as promoters in the tumorigenesis of PC, while the inhibitory functions of lncRNAs in the development of PC have not been fully elucidated yet. LncRNA microarray was adopted to analyze the differential expression of lncRNAs in PC tissues and that in normal peritumoral (NP) tissues. Functional role of lncRNA BM466146.1 on PC was evaluated by gain- and loss-of-function experiments in vivo and in vitro. RNA pull-down, RNA immunoprecipitation, luciferase reporter, and Chromatin-immunoprecipitation assays were performed to assess the mechanism of ZNFTR, respectively. The correlation between the expression of ZNFTR and various clinicopathological characteristics was accessed in PC specimens. This study displayed lncRNA BM466146.1 was downregulated in PC tissues and functioned as a suppressor through regulating the expression of adjacent gene Zinc finger protein 24 (ZNF24), which was assigned as ZNFTR. Mechanistically, ZNFTR interacted with activating transcription factor 3 (ATF3) and sequestered ATF3 away from the ZNF24 promoter, which consequently increased the expression of ZNF24. Further, ZNF24 inhibited the proliferative, metastatic, and pro-angiogenic abilities of PC cells by suppressing transcription of vascular endothelial growth factor A (VEGFA). Therefore, the downregulation of ZNFTR in PC led to the decreased expression of ZNF24, which further resulted in the upregulation of VEGFA to facilitate the development of PC. Meanwhile, ZNFTR was transcriptionally inhibited by the HIF-1α/HDAC1 complex-mediated deacetylation. Clinical results further demonstrated that the low expression of ZNFTR was associated with poor overall survival time. Taken together, our results implicated that ZNFTR was a hypoxia-responsive lncRNA, and functioned as an inhibitor by modulating ATF3/ZNF24/VEGFA pathway in PC.