Long non-coding RNA HNF1A-AS1 functioned as an oncogene and autophagy promoter in hepatocellular carcinoma through sponging hsa-miR-30b-5p

Interaction among inflammasome, autophagy and non-coding RNAs: new horizons for drug

Autophagy and inflammasomes are shown to interact in various situations including infectious disease, cancer, diabetes and neurodegeneration. Since multiple layers of molecular regulators contribute to the interplay between autophagy and inflammasome activation, the detail of such interplay remains largely unknown. Non-coding RNAs (ncRNAs), which have been implicated in regulating an expanding list of cellular processes including immune defense against pathogens and inflammatory response in cancer and metabolic diseases, may join in the crosstalk between inflammasomes and autophagy in physiological or disease conditions. In this review, we summarize the latest research on the interlink among ncRNAs, inflammasomes and autophagy and discuss the emerging role of these three in multiple signaling transduction pathways involved in clinical conditions. By analyzing these intriguing interconnections, we hope to unveil the mechanism inter-regulating these multiple processes and ultimately discover potential drug targets for some refractory diseases.

lncRNA HNF1A-AS1 modulates non-small cell lung cancer progression by targeting miR-149-5p/Cdk6

Growing evidence have shown the important regulation of lncRNAs (long noncoding RNAs) in non-small cell lung cancer (NSCLC). lncRNA hepatocyte nuclear factor 1 homeobox A (HNF1A)-antisense RNA 1 (AS1), an "oncogene", was reported to regulate human tumors progression. However, the molecular mechanism of HNF1A-AS1 involved in the development of NSCLC is still under investigation. In the current study, we found that HNF1A-AS1 was relatively upregulated in both NSCLC patient tissues and cell lines. Functional studies established that overexpression of HNF1A-AS1 promoted cell proliferation, cell cycle, invasion, and migration of NSCLC cells in vitro. The promotion abilities of HNF1A-AS1 on NSCLC cell progression were suppressed via knockdown of HNF1A-AS1. miR-149-5p was then proved to be a novel target of HNF1A-AS1, whose expression was negatively correlated with HNF1A-AS1 in NSCLC patient tissues and cell lines. HNF1A-AS1 increased the expression of cyclin-dependent kinase 6 (Cdk6) via sponging with miR-149-5p. Gain- and loss-of-functional studies indicated that HNF1A-AS1 promoted NSCLC progression partially through inhibition of miR-363-3p and induction of Cdk6. Subcutaneous xenotransplanted tumor model confirmed that interference of HNF1A-AS1 suppressed the tumorigenic ability of NSCLC via upregulation of miR-149-5p and downregulation of Cdk6 in vivo. In conclusion, our findings clarified the biologic significance of the HNF1A-AS1/miR-149-5p/Cdk6 axis in NSCLC progression and provided novel evidence that HNF1A-AS1 may be a new potential therapeutic target for the treatment of NSCLC.

Circulating Noncoding RNAs Have a Promising Future Acting as Novel Biomarkers for Colorectal Cancer

Colorectal cancer (CRC) is one of the most common malignant tumors worldwide, causing a large number of cancer-related deaths each year. Patients are usually diagnosed at advanced and incurable stages due to the lack of suitable screening methods for early detection. Noncoding RNAs (ncRNAs), including small and long noncoding RNAs (lncRNA), are known to have significant regulatory functions, and accumulating evidence suggests that circulating ncRNAs have potential applications as noninvasive biomarkers for diagnosing CRC, evaluating its prognosis, or predicting chemosensitivity in the general population. In this review, we summarize the origins of circulating ncRNAs and provide details of single and multiple circulating ncRNAs that might have roles as diagnostic and prognostic biomarkers in CRC. We end by discussing circulating ncRNAs that may distinguish patients with resistance to chemotherapy.

LncRNA-Regulated Autophagy and its Potential Role in Drug-Induced Liver Injury

INTRODUCTION AND AIM

Autophagy and its regulated pathways participate in many important cellular physiology and pathological processes involving protein aggregates, damaged mitochondria, excessive peroxisomes, ribosomes, and invading pathogens. This study aimed to review recently published studies and further describe the long noncoding RNA (lncRNA)-regulated autophagy during drug-induced liver injury (DILI).

MATERIAL AND METHODS

DILI, autophagy, autophagy-related genes (ATGs), and lncRNA were used as key words to search published studies from PubMed, Google Scholar, and Web of Science. All related studies were reviewed and analyzed.

RESULTS

Many studies explicitly indicated that DILI and its progression to acute liver failure were causatively linked to endoplasmic reticulum stress and subsequently induced autophagy, which protect hepatocytes during DILI. LncRNA, as a noncoding RNA, influences the regulation of the expression of ATGs to manipulate autophagy.

CONCLUSIONS

This review described the recent findings on autophagy and its possible lncRNA-miRNA-associated pathways, thereby providing new insights for further studies on the pathogenesis of DILI.

LncRNAs with miRNAs in regulation of gastric, liver, and colorectal cancers: updates in recent years

Long noncoding RNA (lncRNA) is a kind of RNAi molecule composed of hundreds to thousands of nucleotides. There are several major types of functional lncRNAs which participate in some important cellular pathways. LncRNA-RNA interaction controls mRNA translation and degradation or serves as a microRNA (miRNA) sponge for silencing. LncRNA-protein interaction regulates protein activity in transcriptional activation and silencing. LncRNA guide, decoy, and scaffold regulate transcription regulators of enhancer or repressor region of the coding genes for alteration of expression. LncRNA plays a role in cellular responses including the following activities: regulation of chromatin structural modification and gene expression for epigenetic and cell function control, promotion of hematopoiesis and maturation of immunity, cell programming in stem cell and somatic cell development, modulation of pathogen infection, switching glycolysis and lipid metabolism, and initiation of autoimmune diseases. LncRNA, together with miRNA, are considered the critical elements in cancer development. It has been demonstrated that tumorigenesis could be driven by homeostatic imbalance of lncRNA/miRNA/cancer regulatory factors resulting in biochemical and physiological alterations inside the cells. Cancer-driven lncRNAs with other cellular RNAs, epigenetic modulators, or protein effectors may change gene expression level and affect the viability, immortality, and motility of the cells that facilitate cancer cell cycle rearrangement, angiogenesis, proliferation, and metastasis. Molecular medicine will be the future trend for development. LncRNA/miRNA could be one of the potential candidates in this category. Continuous studies in lncRNA functional discrepancy between cancer cells and normal cells and regional and rational genetic differences of lncRNA profiles are critical for clinical research which is beneficial for clinical practice.

Non-coding RNAs, epigenetics, and cancer: tying it all together

While only a small part of the human genome encodes for proteins, biological functions for the so-called junk genome are increasingly being recognized through high-throughput technologies and mechanistic experimental studies. Indeed, novel mechanisms of gene regulation are being discovered that require coordinated interaction between DNA, RNA, and proteins. Therefore, interdisciplinary efforts are still needed to decipher these complex transcriptional networks. In this review, we discuss how non-coding RNAs (ncRNAs) are epigenetically regulated in cancer and metastases and consequently how ncRNAs participate in the sculpting of the epigenetic profile of a cancer cell, thus modulating the expression of other RNA molecules. In the latter case, ncRNAs not only affect the DNA methylation status of certain genomic loci but also interact with histone-modifying complexes, changing the structure of the chromatin itself. We present several examples of epigenetic changes causing aberrant expression of ncRNAs in the context of tumor progression. Interestingly, there are also important epigenetic changes and transcriptional regulatory effects derived from their aberrant expression. As ncRNAs can also be used as biomarkers for diagnosis and prognosis or explored as potential targets, we present insights into the use of ncRNAs for targeted cancer therapy.

The therapeutic role of long non-coding RNAs in human diseases: A focus on the recent insights into autophagy

Long non-coding RNA (lncRNA) is a class of non-coding RNA with ≥200 nucleotides in length which are involved as critical regulators in various cellular processes. LncRNAs contribute to the development and progression of many human diseases. Autophagy is a key catabolic process which helps to maintain the cellular homeostasis through the decay of damaged or unwanted proteins and dysfunctional cytoplasmic organelles. The impairment of the autophagy process has been described in numerous diseases. The autophagy possess can have either a protective or a detrimental role in cells depending on its activation status and other cellular conditions. LncRNAs have been shown to have an important function in the regulation of important biological processes such as autophagy. The relationship between lncRNAs and autophagy has been shown to be involved in the progression and possibly in the prevention of many diseases. In this review, recent findings on the regulatory roles of lncRNAs in the cell autophagy pathway, as well as their relevance to different diseases such as cardiovascular disease, cerebral ischemic stroke and cancer are highlighted.

Long noncoding RNAs in cancer cells

Long noncoding RNA (lncRNA) has recently been investigated as key modulators that regulate many biological processes in human cancers via diverse mechanisms. LncRNAs can interact with macromolecules such as DNA, RNA, or protein to exert cellular effects and to act as either tumor promoters or tumor suppressors in various malignancies. Moreover, the aberrant expression of lncRNAs may be detected in multiple cancer phenotypes by employing the rapidly developing modern gene chip technology and bioinformatics analysis. Herein, we highlight the mechanisms of action of lncRNAs, their functional cellular roles and their involvement in cancer progression. Finally, we provide an overview of recent progress in the lncRNA field and future potential for lncRNAs as cancer diagnostic markers and therapeutics.

Autophagy-Modulating Long Non-coding RNAs (LncRNAs) and Their Molecular Events in Cancer

Cancer is a global threat of health. Cancer incidence and death is also increasing continuously because of poor understanding of diseases. Although, traditional treatments (surgery, radiotherapy, and chemotherapy) are effective against primary tumors, death rate is increasing because of metastasis development where traditional treatments have failed. Autophagy is a conserved regulatory process of eliminating proteins and damaged organelles. Numerous research revealed that autophagy has dual sword mechanisms including cancer progressions and suppressions. In most of the cases, it maintains homeostasis of cancer microenvironment by providing nutritional supplement under starvation and hypoxic conditions. Over the past few decades, stunning research evidence disclosed significant roles of long non-coding RNAs (lncRNAs) in the regulation of autophagy. LncRNAs are RNA containing more than 200 nucleotides, which have no protein-coding ability but they are found to be expressed in most of the cancers. It is also proved that, autophagy-modulating lncRNAs have significant impacts on pro-survival or pro-death roles in cancers. In this review, we highlighted the recently identified autophagy-modulating lncRNAs, their signaling transduction in cancer and mechanism in cancer. This review will explore newly emerging knowledge of cancer genetics and it may provide novel targets for cancer therapy.

Diverse Functions of Autophagy in Liver Physiology and Liver Diseases

Autophagy is a catabolic process by which eukaryotic cells eliminate cytosolic materials through vacuole-mediated sequestration and subsequent delivery to lysosomes for degradation, thus maintaining cellular homeostasis and the integrity of organelles. Autophagy has emerged as playing a critical role in the regulation of liver physiology and the balancing of liver metabolism. Conversely, numerous recent studies have indicated that autophagy may disease-dependently participate in the pathogenesis of liver diseases, such as liver hepatitis, steatosis, fibrosis, cirrhosis, and hepatocellular carcinoma. This review summarizes the current knowledge on the functions of autophagy in hepatic metabolism and the contribution of autophagy to the pathophysiology of liver-related diseases. Moreover, the impacts of autophagy modulation on the amelioration of the development and progression of liver diseases are also discussed.

The HNF1α-Regulated LncRNA HNF1α-AS1 Is Involved in the Regulation of Cytochrome P450 Expression in Human Liver Tissues and Huh7 Cells

Expression of cytochrome P450s (P450s) is regulated by epigenetic factors, such as DNA methylation, histone modifications, and noncoding RNAs through different mechanisms. Among these factors, long noncoding RNAs (lncRNAs) have been shown to play important roles in the regulation of gene expression; however, little is known about the effects of lncRNAs on the regulation of P450 expression. The aim of this study was to explore the role of lncRNAs in the regulation of P450 expression by using human liver tissues and hepatoma Huh7 cells. Through lncRNA microarray analysis and quantitative polymerase chain reaction in human liver tissues, we found that the lncRNA hepatocyte nuclear factor 1 alpha antisense 1 (HNF1α-AS1), an antisense RNA of HNF1α, is positively correlated with the mRNA expression of CYP2C8, 2C9, 2C19, 2D6, 2E1, and 3A4 as well as pregnane X receptor (PXR) and constitutive androstane receptor (CAR). Gain- and loss-of-function studies in Huh7 cells transfected with small interfering RNAs or overexpression plasmids showed that HNF1α not only regulated the expression of HNF1α-AS1 and P450s, but also regulated the expression of CAR, PXR, and aryl hydrocarbon receptor (AhR). In turn, HNF1α-AS1 regulated the expression of PXR and most P450s without affecting the expression of HNF1α, AhR, and CAR. Moreover, the rifampicin-induced expression of P450s was also affected by HNF1α and HNF1α-AS1. In summary, the results of this study suggested that HNF1α-AS1 is involved in the HNF1α-mediated regulation of P450s in the liver at both basal and drug-induced levels.

LncRNA MALAT1 potentiates autophagy‑associated cisplatin resistance by regulating the microRNA‑30b/autophagy‑related gene 5 axis in gastric cancer

Gastric cancer (GC) is the fourth most common type of cancer worldwide and chemoresistance is a major obstacle to successful GC treatment. In the present study, reverse transcription‑quantitative polymerase chain reaction analysis was used to measure the expression of metastasis‑associated lung adenocarcinoma transcript 1 (MALAT1) and microRNA (miR)‑30b. Western blot analysis was conducted to detect the protein expression of autophagy‑related gene 5 (ATG5), p62 and LC3 (LC3‑I and LC3‑II). Cell viability and half maximal inhibitory concentration were determined by the Cell Counting Kit‑8 assay. The green fluorescent protein (GFP)‑LC3‑positive cell percentage was determined by the GFP‑LC3 puncta experiment. Luciferase reporter and RNA immunoprecipitation assays were used to explore the molecular associations among MALAT1, miR‑30b and ATG5. MALAT1 was found to be highly expressed in CDDP‑resistant AGS(AGS/CDDP) cells and CDDP‑resistant HGC‑27 (HGC‑27/CDDP) cells. Cell viability was markedly increased in MALAT1‑overexpressing AGS/CDDP cells, but was notably reduced in MALAT1‑depleted HGC‑27/CDDP cells. Moreover, MALAT1 potentiated CDDP resistance by facilitating autophagy in AGS/CDDP and HGC‑27/CDDP cells. Further investigations demonstrated that MALAT1 inhibited miR‑30b expression by direct interaction. Moreover, miR‑30b abolished MALAT1‑induced CDDP resistance by inhibiting autophagy in AGS/CDDP and HGC‑27/CDDP cells. Furthermore, ATG5 was found to be a target of miR‑30b. miR‑30b weakened resistance to CDDP by inhibiting autophagy in AGS/CDDP and HGC‑27/CDDP cells, while this effect was abrogated by increased ATG5 expression. Additionally, MALAT1 sequestered miR‑30b from ATG5 to increase ATG5 expression in AGS/CDDP and HGC‑27/CDDP cells. Therefore, MALAT1 potentiated autophagy‑related CDDP resistance through suppressing the miR‑30b/ATG5 axis in AGS/CDDP and HGC‑27/CDDP cells, indicating that it may represent a promising target for the reversal of chemoresistance in GC.

Regulatory effects of lncRNAs and miRNAs on autophagy in malignant tumorigenesis

Autophagy is an important process in endogenous substrate degradation by lysosomes within cells, with a degree of evolutionary conservation. Like apoptosis and cell senescence, cell autophagy is a very important biological phenomenon involving the development and growth of biological processes. Abnormal autophagy may lead to tumorigenesis. In recent years, increasing studies have demonstrated that long non-coding RNAs (lncRNAs) and miRNAs can regulate cell autophagy by modulating targetting gene expression. In this review, we will provide an overview of lncRNAs and miRNAs in autophagy modulation and new insights into the underlying mechanisms, as well as their potential utilization in disease diagnosis, prognosis, and therapy.

Prognostic role of long non-coding RNA HNF1A-AS1 in Chinese cancer patients: a meta-analysis

Background

Long non-coding RNAs (LncRNAs) play important roles in tumorigenesis and progression. Recent studies have demonstrated that LncRNA HNF1A antisense RNA 1 (HNF1A-AS1) is aberrantly expressed in several types of cancers and is associated with poor outcomes. This meta-analysis was conducted to investigate the relationship between HNF1A-AS1 expression and clinical outcomes in cancer patients.

Methods

We searched PubMed, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), and Wan Fang databases (updated until December 31, 2017) for literature. A total of eight studies with 789 cancer patients were finally included in the present meta-analysis.

Results

The results showed that high expression of HNF1A-AS1 significantly predicted poor overall survival (HR=3.10, 95% CI: 1.58-6.11, P=0.001), which was further validated using The Cancer Genome Atlas (TCGA) dataset. Moreover, high HNF1A-AS1 expression was also associated with advanced TNM stage (OR=3.32, 95% CI: 2.28-4.83, P<0.001), lymph node metastasis (OR=3.08, 95% CI: 1.95-4.85, P<0.001), and distant metastasis (OR=5.53, 95% CI: 1.94-15.77, P=0.001).

Conclusion

Our results suggested that elevated HNF1A-AS1 was associated with poor clinical outcomes and might serve as a potential prognostic biomarker of cancer.

Elevated serum level of lncRNA-HIF1A-AS1 as a novel diagnostic predictor for worse prognosis in colorectal carcinoma

To evaluate the diagnostic efficacy and prognostic value of serum long non-coding RNA (lncRNA) HIF 1alpha-antisense RNA 1 (HIF1A-AS1) in patients with colorectal carcinoma (CRC). We obtained serum samples from 151 CRC patients and 160 health controls. Serum level of HIF1A-AS1 was detected via real-time PCR (RT-PCR). Receiver operating characteristics (ROC) curve analysis was conducted to determine the diagnostic value of HIF1A-AS1. Then HIF1A-AS1 in CRC was divided into high- and low-expression groups, and the associations of the HIF1A-AS1 serum level with clinicopathological features and prognosis were analyzed. Serum level of HIF1A-AS1 was significantly increased from CRC patients as compared to those of health controls (P< 0.05). ROC curve analysis revealed a relative high diagnostic performance of HIF1A-AS1 to distinguish CRC from health controls, with the area under the curves (AUC) of 0.960 (95% CI: 0.940 ∼ 0.980; P< 0.001). Kaplan-Meier analysis showed that differentiation degree, tumor size, TNM stage, T stage, N stage, M stage and serum level of HIF1A-AS1 were all linked to CRC prognosis (All P< 0.05). Compared to CRC patients with low HIF1A-AS1 expression, high expression of patients were associated with a shorter 5-year-survival rate (P< 0.001). Multivariate Cox regression analysis revealed that lower differentiation degree, tumor > 5 cm and higher expression of HIF1A-AS1 were independent risk factors affecting the survival rate of patients with CRC (P< 0.05). Our results illustrated that elevated serum HIF1AAS1 could be clinically functioned as a potential biomarker for CRC diagnoses and prognosis.

A Systematic Review of Long Noncoding RNAs in Hepatocellular Carcinoma: Molecular Mechanism and Clinical Implications

Hepatocellular carcinoma (HCC) has the second highest mortality rate worldwide among all cancers. Previous studies have revealed the significant involvement of long noncoding RNAs (lncRNAs) in numerous human cancers including HCC. Both oncogenic and tumor repressive lncRNAs have been identified and implicated in the complex process of hepatocarcinogenesis. They can be further explored as prospective diagnostic, prognostic, and therapeutic markers for HCC. An in-depth understanding of lncRNAs' mechanism in HCC is therefore required to fully explore their potential role. In the current review, we will concentrate on the underlying function, molecular mechanisms, and potential clinical implications of lncRNA in HCC.

The emergence of long non-coding RNAs in hepatocellular carcinoma: an update

Hepatocellular carcinoma (HCC) accounting for roughly 90% of all primary liver neoplasms is the sixth most frequent neoplasm and the second prominent reason of tumor fatality worldwide. As regulators of diverse biological processes, long non-coding RNAs (lncRNAs) are involved in onset and development of neoplasms. With the continuous booming of well-featured lncRNAs in HCC from 2016 to now, we reviewed the newly-presented comprehension about the relationship between lncRNAs and HCC in this study. To be specific, we summarized the overview function and study tools of lncRNAs, elaborated the roles of lncRNAs in HCC, and sketched the molecule mechanisms of lncRNAs in HCC. In addition, the application of lncRNAs serving as biomarkers in early diagnosis and outcome prediction of HCC patients was highlighted.

Role of lncRNAs in the cancer development and progression and their regulation by various phytochemicals

Long non coding RNAs (lncRNAs) are involved in modulating the expression of other non-coding RNAs (ncRNA), such as microRNAs, or target proteins through the epigenetic, transcriptional, or post-transcriptional regulations. Genomic mutations in cancer reside inside regions that do not code for proteins and these regions are often transcribed into long non coding RNAs (lncRNAs). Emerging evidences have revealed an intense involvement of lncRNAs in the cancer development and progression. Recently, emerging evidences have depicted that the phytochemicals interact with lncRNAs to modulate their activities. Such findings are highly important for the identification of therapeutic strategies against diseases that are particularly associated with an aberrant lncRNA signaling. This review aims at deciphering the role of lncRNAs in the cancer development and progression, and their regulation by various phytochemicals.

Non-coding RNAs in hepatocellular carcinoma: molecular functions and pathological implications

Hepatocellular carcinoma (HCC) is a leading lethal malignancy worldwide. However, the molecular mechanisms underlying liver carcinogenesis remain poorly understood. Over the past two decades, overwhelming evidence has demonstrated the regulatory roles of different classes of non-coding RNAs (ncRNAs) in liver carcinogenesis related to a number of aetiologies, including HBV, HCV and NAFLD. Among the ncRNAs, microRNAs, which belong to a distinct class of small ncRNAs, have been proven to play a crucial role in the post-transcriptional regulation of gene expression. Deregulation of microRNAs has been broadly implicated in the inactivation of tumour-suppressor genes and activation of oncogenes in HCC. Modern high-throughput sequencing analyses have unprecedentedly identified a very large number of non-coding transcripts. Divergent groups of long ncRNAs have been implicated in liver carcinogenesis through interactions with DNA, RNA or proteins. Overall, ncRNAs represent a burgeoning field of cancer research, and we are only beginning to understand the importance and complicity of the ncRNAs in liver carcinogenesis. In this Review, we summarize the common deregulation of small and long ncRNAs in human HCC. We also comprehensively review the pathological roles of ncRNAs in liver carcinogenesis, epithelial-to-mesenchymal transition and HCC metastasis and discuss the potential applications of ncRNAs as diagnostic tools and therapeutic targets in human HCC.

The HNF1α-regulated lncRNA HNF1A-AS1 reverses the malignancy of hepatocellular carcinoma by enhancing the phosphatase activity of SHP-1

BACKGROUND

Our previous study has demonstrated that hepatocyte nuclear factor 1α (HNF1α) exerts potent therapeutic effects on hepatocellular carcinoma (HCC). However, the molecular mechanisms by which HNF1α reverses HCC malignancy need to be further elucidated.

METHODS

lncRNA microarray was performed to identify the long noncoding RNAs (lncRNAs) regulated by HNF1α. Chromatin immunoprecipitation and luciferase reporter assays were applied to clarify the mechanism of the transcriptional regulation of HNF1α to HNF1A antisense RNA 1 (HNF1A-AS1). The effect of HNF1A-AS1 on HCC malignancy was evaluated in vitro and in vivo. RNA pulldown, RNA-binding protein immunoprecipitation and the Bio-Layer Interferometry assay were used to validate the interaction of HNF1A-AS1 and Src homology region 2 domain-containing phosphatase 1 (SHP-1).

RESULTS

HNF1α regulated the expression of a subset of lncRNAs in HCC cells. Among these lncRNAs, the expression levels of HNF1A-AS1 were notably correlated with HNF1α levels in HCC cells and human HCC tissues. HNF1α activated the transcription of HNF1A-AS1 by directly binding to its promoter region. HNF1A-AS1 inhibited the growth and the metastasis of HCC cells in vitro and in vivo. Moreover, knockdown of HNF1A-AS1 reversed the suppressive effects of HNF1α on the migration and invasion of HCC cells. Importantly, HNF1A-AS1 directly bound to the C-terminal of SHP-1 with a high binding affinity (KD = 59.57 ± 14.29 nM) and increased the phosphatase activity of SHP-1. Inhibition of SHP-1 enzymatic activity substantially reversed the HNF1α- or HNF1A-AS1-induced reduction on the metastatic property of HCC cells.

CONCLUSIONS

Our data revealed that HNF1A-AS1 is a direct transactivation target of HNF1α in HCC cells and involved in the anti-HCC effect of HNF1α. HNF1A-AS1 functions as phosphatase activator through the direct interaction with SHP-1. These findings suggest that regulation of the HNF1α/HNF1A-AS1/SHP-1 axis may have beneficial effects in the treatment of HCC.

Clinical significance of C/D box small nucleolar RNA U76 as an oncogene and a prognostic biomarker in hepatocellular carcinoma

BACKGROUND

Recent evidence has suggested novel roles of small nucleolar RNAs (snoRNAs) in tumorigenicity. However, the roles of C/D box snoRNA U76 (SNORD76) in the development of hepatocellular carcinoma (HCC) remain unknown. Herein, we systematically evaluated dysregulation of snoRNAs in HCC and clarified the biomarker potential and biological significance of SNORD76 in HCC.

METHODS

We performed quantitative analyses of the expression of SNORD76 in 66 HCC specimens to compare its expression pattern between tumor tissue and matched non-tumor tissue. The effects of SNORD76 on HCC tumorigenicity were investigated in SK-Hep1 and Huh7 cells as well as in a xenograft nude mouse model.

RESULTS

SNORD76 expression was significantly upregulated in HCC tissues compared to corresponding non-tumor tissues. This upregulation of SNORD76 in HCC tumors was significantly associated with poorer patient survival. Furthermore, inhibiting SNORD76 expression suppressed cell proliferation by inducing G0/G1 cell cycle arrest and apoptosis. Low SNORD76 expression also resulted in decreased HCC growth in an animal model. Conversely, overexpressing SNORD76 promoted cell proliferation. SNORD76 increased HCC cell invasion by inducing epithelial-mesenchymal transition (EMT). Finally, we found that SNORD76 promoted HCC tumorigenicity through activation of the Wnt/β-catenin pathway.

CONCLUSIONS

Therefore, we demonstrated for the first time that SNORD76 may function as a novel tumor promoter in HCC and may serve as a promising prognostic biomarker in patients with HCC.

MiR-320d suppresses the progression of breast cancervialncRNA HNF1A-AS1 regulation and SOX4 inhibition

MicroRNA-320d (miR-320d) is a novel cancer-related miRNA and functions as a tumor suppressor in human cancers.

LncRNA UCA1 attenuates autophagy-dependent cell death through blocking autophagic flux under arsenic stress

Arsenic (As) is a naturally toxin which exists ubiquitously in foods and various environment media, incurring diverse toxicities and health problems. Previous studies have shown that oxidative stress, genotoxic damage and pro-apoptotic pathways are ascribed to As-associated detrimental effects. Meanwhile, epigenetic regulations (such as miRNAs and histone modifications) were also reported to contribute to As-induced adverse effects. Nonetheless, whether long non-coding RNAs (LncRNAs) are indispensable for the regulation of As-induced biological outcomes are nearly unknown. In this study, we identified that a lncRNA UCA1 was markedly induced by As treatment in human hepatocytes. Functional assessments revealed that UCA1 played a critical role in protecting hepatocytes from As-induced autophagy inhibition. Furthermore, through RNA-seq assay, oxidative stress induced growth inhibitor 1 (OSGIN1) was uncovered to be the most responsive target downstream of UCA1, and miR-184 acted as an intermediate for the regulation of UCA1 on the level of OSGIN1 through a competing endogenous RNAs (ceRNAs) mechanism. Further mechanistic investigations demonstrated that UCA1/OSGIN1 signaling contributed to As-induced autophagic flux blockage through activating mTOR/p70S6 K cascade, resulting in compromised cell death. Collectively, our study deciphered a lncRNA-dictated molecular mechanism responsible for As toxicity: UCA1 leads a protective role against As-induced cell death through blocking autophagic flux.

Long noncoding RNAs in the initiation, progression, and metastasis of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide. Despite awareness of risk factors for the development of HCC and advances in the diagnosis and clinical management of the disease, the molecular mechanisms underlying hepatocarcinogenesis remain poorly understood. Recent experimental studies provide strong evidence that long noncoding RNAs (lncRNAs), non-protein-coding transcripts with lengths >200 basepairs, contribute to the pathogenesis of numerous human diseases. Over the past decade, a role for lncRNAs in the initiation, progression, and metastasis of HCC has likewise emerged and developed into a highly active area of research. Although many lncRNAs appear to be dysregulated in HCC, extensive functional characterization has been performed on only a small proportion of these candidates to date. This review summarizes select lncRNAs that have been shown to wield functional relevance in the initiation, progression, or metastasis of HCC, focusing on the specific mechanisms by which lncRNA effects might be linked to clinical manifestations of the disease. In addition, an overview of circulating lncRNAs that have been identified as potential biomarkers for the diagnosis and prognosis of HCC is provided.

Knockdown of lncRNA-XIST enhances the chemosensitivity of NSCLC cells via suppression of autophagy

Drug resistance is the major factor contributing to the failure of chemotherapy in non-small cell lung cancer (NSCLC) patients. Emerging evidence suggests that autophagy plays a vital role in the chemoresistance of many types of tumors. However, the exact mechanism underlying the chemoresistance of NSCLC is still elusive, and it is unclear whether lncRNA-XIST is involved in autophagy and chemoresistance of NSCLC. In the present study, we demonstrated that lncRNA-XIST was overexpressed in NSCLC tumor samples, and knockdown of lncRNA-XIST significantly decreased autophagy by regulation of ATG7 as determined by qPCR and by western blotting. Furthermore, we found that miR-17 was upregulated following knockdown of lncRNA-XIST, and miR-17 mimics decreased the protein levels of ATG7 by directly targeting the 3'-untranslated region of ATG7 mRNA as determined by RT-qPCR and by western blotting. Furthermore, we found that the expression level of lncRNA-XIST was markedly increased in cisplatin-resistant A549 cells as determined by q-PCR. Knockdown of lncRNA-XIST restored the chemosensitivity of cisplatin-resistant A549 cells to cisplatin, which was reversed by miR-17 inhibitor and overexpression of ATG7 as determined by CCK8 assays. This study provides evidence that lncRNA-XIST may be a potential marker of poor response to cisplatin chemotherapy in NSCLC patients and the pathway 'lncRNA-XIST/miR-17/autophagy' may be a promising target for patients with chemoresistant NSCLC.

Long noncoding RNAs act as regulators of autophagy in cancer

Long noncoding RNAs (lncRNAs) have emerged as critical regulators in various cellular processes. Studies have disclosed an important function of lncRNAs in the regulation of autophagy, a crucial cellular homeostatic mechanism that plays a pro-survival or pro-death role in cancer. Deregulation of lncRNAs can contribute to tumorigenesis and cancer progression, wherein lncRNAs can act as oncogenes or tumor suppressors. In this review, we highlight the recent advances in understanding the relationship between lncRNAs and autophagy regulation in cancer. Exploiting the newly emerging knowledge of the lncRNA-autophagy-cancer axis may provide novel targets for cancer therapy.

Profiling, clinicopathological correlation and functional validation of specific long non-coding RNAs for hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is one of the most prevalent and aggressive malignancies worldwide. Studies seeking to advance the overall understanding of lncRNA profiling in HCC remain rare.

Methods

The transcriptomic profiling of 12 HCC tissues and paired adjacent normal tissues was determined using high-throughput RNA sequencing. Fifty differentially expressed mRNAs (DEGs) and lncRNAs (DELs) were validated in 21 paired HCC tissues via quantitative real-time PCR. The correlation between the expression of DELs and various clinicopathological characteristics was analyzed using Student’s t-test or linear regression. Co-expression networks between DEGs and DELs were constructed through Pearson correlation co-efficient and enrichment analysis. Validation of DELs’ functions including proliferation and migration was performed via loss-of-function RNAi assays.

Results

In this study, we identified 439 DEGs and 214 DELs, respectively, in HCC. Furthermore, we revealed that multiple DELs, including NONHSAT003823, NONHSAT056213, NONHSAT015386 and especially NONHSAT122051, were remarkably correlated with tumor cell differentiation, portal vein tumor thrombosis, and serum or tissue alpha fetoprotein levels. In addition, the co-expression network analysis between DEGs and DELs showed that DELs were involved with metabolic, cell cycle, chemical carcinogenesis, and complement and coagulation cascade-related pathways. The silencing of the endogenous level of NONHSAT122051 or NONHSAT003826 could significantly attenuate the mobility of both SK-HEP-1 and SMMC-7721 HCC cells.

Conclusion

These findings not only add knowledge to the understanding of genome-wide transcriptional evaluation of HCC but also provide promising targets for the future diagnosis and treatment of HCC.

CXXC4 activates apoptosis through up-regulating GDF15 in gastric cancer

Worldwide, gastric cancer is one of the most fatal cancers. Epigenetic alterations in gastric cancer play important roles in silencing of tumor suppressor genes. We previously found that CXXC finger protein 4 (CXXC4) was a novel tumor suppressor in gastric cancer. In this report, we demonstrated that CXXC4 inhibited growth of gastric cancer cells as a pro-apoptotic factor. This inhibition could be reversed by the pan-caspase inhibitor called Z-VAD-FMK. However, CXXC4 with mutations in its DNA binding domain failed to induce apoptosis. Growth differentiation factor 15 (GDF15) was identified as one of potential targets responsible for CXXC4-induced apoptosis. CXXC4 activated GDF15 transcription through enhancing the interaction of transcription factor Sp1 with GDF15 promoter. In summary, the nuclear protein CXXC4 activated apoptosis in gastric cancer through up-regulating its novel potential downstream target GDF15. GDF15 might be a promising target for clinical treatment of gastric cancer with CXXC4 deficiency.

Long non-coding RNAs involved in autophagy regulation

Autophagy degrades non-functioning or damaged proteins and organelles to maintain cellular homeostasis in a physiological or pathological context. Autophagy can be protective or detrimental, depending on its activation status and other conditions. Therefore, autophagy has a crucial role in a myriad of pathophysiological processes. From the perspective of autophagy-related (ATG) genes, the molecular dissection of autophagy process and the regulation of its level have been largely unraveled. However, the discovery of long non-coding RNAs (lncRNAs) provides a new paradigm of gene regulation in almost all important biological processes, including autophagy. In this review, we highlight recent advances in autophagy-associated lncRNAs and their specific autophagic targets, as well as their relevance to human diseases such as cancer, cardiovascular disease, diabetes and cerebral ischemic stroke.

Long non-coding RNAs as biomarkers and therapeutic targets: Recent insights into hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most prevalent primary liver cancer worldwide, and the survival rates of patients with HCC remains quite low after 5years. Long non-coding RNAs (LncRNAs) are a novel class of non-coding RNAs that are capable of regulating gene expression at various levels. Recent works have demonstrated that lncRNAs are often dysregulated in HCC, and the dysregulation of some of these lncRNAs are associated with the clinicopathological features of HCC. They regulate cell proliferation, apoptosis, autophagy, Epithelial-Mesenchymal Transition (EMT), invasion and metastasis of HCC by modulating gene expression and cancer-related signaling pathways, and thus contribute to the onset and progression of HCC. In this review, we provide a comprehensive survey of dysregulated lncRNAs in HCC, with particular focus on the functions and regulatory mechanisms of several essential and important lncRNAs, and discuss their potential clinical application as early diagnostic and/or prognostic biomarkers or therapeutic targets for HCC.

Long non-coding RNA HNF1A-AS1 promotes proliferation and suppresses apoptosis of bladder cancer cells through upregulating Bcl-2

Emerging evidences have indicated that long non-coding RNAs (lncRNAs) are pivotal regulators of tumor development and progression. HNF1A-AS1 (HNF1A antisense RNA 1, C12 or f27) is a novel long non-coding RNA that acts as a potential biomarker and is involved in development and progression of several cancers. Nevertheless, we know nothing about the clinical significance and molecular mechanism of HNF1A-AS1 in bladder cancer. In this study, we found that HNF1A-AS1 is significantly up-regulated in bladder cancer. Further experiments had demonstrated that silencing HNF1A-AS1 in bladder cancer cells could inhibit the proliferation and induce apoptosis. Mechanistically, we found down-regulated of HNF1A-AS1 increased the expression of miR-30b-5p and subsequently inhibited the expression of Bcl-2, in a ceRNA-dependent way. Moreover, knockdown of miR-30b-5p reversed cell proliferation inhibition and cell apoptosis induced by silencing HNF1A-AS1. In conclusions, we demonstrated that HNF1A-AS1 plays an important regulatory role in bladder cancer and shed new light on lncRNA-directed diagnostic and therapeutics in bladder cancer.

Knockdown of lncRNA HNF1A-AS1 inhibits oncogenic phenotypes in colorectal carcinoma

Long non-coding RNAs (lncRNAs) have been demonstrated to serve important roles in the development and progression of cancer. Recently HNF1A antisense RNA 1 (HNF1A‑AS1), a lncRNA, has been reported as exhibiting a potential oncogenic role in the development of many types of cancer. However, the expression and the role of HNF1A‑AS1 in colorectal carcinoma (CRC) remains unclear. In the present study, the role of HNF1A‑AS1 in CRC was examined for the first time and its correlation with CRC cell biological behaviors was analyzed. The results demonstrated that HNF1A‑AS1 was distinctly upregulated in CRC tissues and associated with CRC metastasis to the lymph nodes. Reverse transcription‑quantitative polymerase chain reaction revealed that HNF1A‑AS1 was also upregulated in CRC cell lines and localized in the nucleus. In addition, knockdown of HNF1A‑AS1 expression notably inhibited CRC cell proliferation, migration, invasion and colony formation, and suppressed S‑phase entry in vitro. Taken together, these results suggested that HNF1A‑AS1 might serve as a promising prognostic marker for CRC tumorigenesis and progression.

Genetic variants of cell cycle pathway genes predict disease-free survival of hepatocellular carcinoma

Disruption of the cell cycle pathway has previously been related to development of human cancers. However, associations between genetic variants of cell cycle pathway genes and prognosis of hepatocellular carcinoma (HCC) remain largely unknown. In this study, we evaluated the associations between 24 potential functional single nucleotide polymorphisms (SNPs) of 16 main cell cycle pathway genes and disease‐free survival (DFS) of 271 HCC patients who had undergone radical surgery resection. We identified two SNPs, i.e., SMAD3 rs11556090 A>G and RBL2 rs3929G>C, that were independently predictive of DFS in an additive genetic model with false‐positive report probability (FPRP) <0.2. The SMAD3 rs11556090G allele was associated with a poorer DFS, compared with the A allele [hazard ratio (HR) = 1.46, 95% confidential interval (95% CI) = 1.13–1.89, P = 0.004]; while the RBL2 rs3929 C allele was associated with a superior DFS, compared with the G allele (HR = 0.74, 95% CI = 0.57–0.96, P = 0.023). Additionally, patients with an increasing number of unfavorable genotypes (NUGs) of these loci had a significant shorter DFS (P_trend = 0.0001). Further analysis using receiver operating characteristic (ROC) curves showed that the model including the NUGs and known prognostic clinical variables demonstrated a significant improvement in predicting the 1‐year DFS (P = 0.011). Moreover, the RBL2 rs3929 C allele was significantly associated with increased mRNA expression levels of RBL2 in liver tissue (P = 1.8 × 10⁻⁷) and the whole blood (P = 3.9 × 10⁻¹⁴). Our data demonstrated an independent or a joint effect of SMAD3 rs11556090 and RBL2 rs3929 in the cell cycle pathway on DFS of HCC, which need to be validated by large cohort and biological studies.

HNF1A‑AS1 promotes growth and metastasis of esophageal squamous cell carcinoma by sponging miR‑214 to upregulate the expression of SOX-4

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignancies in the world, marked by dysphagia and weight loss, bringing great suffering to patients. HNF1A‑AS1 (HAS1), a long non-coding RNA (lncRNA), has been identified prevalently involved in various human cancers. However, the exact effects and molecular mechanisms of HAS1 in ESCC progression are still elusive. In this study, upregulated expression of HAS1 was detected in ESCC tissues and four human ESCC cell lines (KYSE70, KYSE450, EC109 and EC970) compared with normal tissues and cell lines. Small interfering RNA (siRNA)-mediated knockdown of HAS1 largely suppressed cell proliferation and promoted cell apoptosis in KYSE70 and EC109 cells. The decreased expression of proliferation marker proteins and elevated level of apoptosis marker proteins further verified that HAS1‑siRNA suppressed cell viability in ESCC cells. Besides, the silence of HAS1 strongly reduced the wound closing rate and the number of invasive cells compared with control group. HAS1-siRNA also restrained the expression of migration marker proteins matrix metalloproteinase-9 (MMP-9) and vascular endothelial cell growth factor (VEGF). In addition, miR‑214 was predicted as a direct target of HAS1 by bioinformatics analysis. Downregulated expression of miR‑214 was elevated in KYSE70 and EC109 cells transfected with HAS1-siRNA. Subsequently, elevated expression of miR‑214 was suppressed by co-transfecting with miR‑214 inhibitor in EC109 cells pretreated with HAS1-siRNA. The result of luciferase activity assay showed that luciferase activity was strongly weakened by the combination of LncR-HAS1 WT and miR‑214 mimic. Moreover, the expression of SOX-4, a predicted target gene of miR‑214, was suppressed by HAS1-siRNA and was increased by miR‑214 inhibitor. HAS1-siRNA counteracted the effect of miR‑214 inhibitor on cell viability and mobility in EC109 cells. Finally, the in vivo experiment revealed that HAS1-siRNA abated the role of miR‑214 inhibitor in promoting tumor growth and metastasis. miR-214 also mediated the effect of HAS1 on upregulating the expression of SOX-4 in vivo. Taken together, our study indicated a HAS1-miR‑214-SOX-4 pathway in regulating the growth and metastasis of ESCC, providing a promising target for ESCC therapy.

The emergence of noncoding RNAs as Heracles in autophagy

Macroautophagy/autophagy is a catabolic process that is widely found in nature. Over the past few decades, mounting evidence has indicated that noncoding RNAs, ranging from small noncoding RNAs to long noncoding RNAs (lncRNAs) and even circular RNAs (circRNAs), mediate the transcriptional and post-transcriptional regulation of autophagy-related genes by participating in autophagy regulatory networks. The differential expression of noncoding RNAs affects autophagy levels at different physiological and pathological stages, including embryonic proliferation and differentiation, cellular senescence, and even diseases such as cancer. We summarize the current knowledge regarding noncoding RNA dysregulation in autophagy and investigate the molecular regulatory mechanisms underlying noncoding RNA involvement in autophagy regulatory networks. Then, we integrate public resources to predict autophagy-related noncoding RNAs across species and discuss strategies for and the challenges of identifying autophagy-related noncoding RNAs. This article will deepen our understanding of the relationship between noncoding RNAs and autophagy, and provide new insights to specifically target noncoding RNAs in autophagy-associated therapeutic strategies.

Long Non-Coding RNAs: Key Regulators of Epithelial-Mesenchymal Transition, Tumour Drug Resistance and Cancer Stem Cells

Epithelial mesenchymal transition (EMT), the adoption by epithelial cells of a mesenchymal-like phenotype, is a process co-opted by carcinoma cells in order to initiate invasion and metastasis. In addition, it is becoming clear that is instrumental to both the development of drug resistance by tumour cells and in the generation and maintenance of cancer stem cells. EMT is thus a pivotal process during tumour progression and poses a major barrier to the successful treatment of cancer. Non-coding RNAs (ncRNA) often utilize epigenetic programs to regulate both gene expression and chromatin structure. One type of ncRNA, called long non-coding RNAs (lncRNAs), has become increasingly recognized as being both highly dysregulated in cancer and to play a variety of different roles in tumourigenesis. Indeed, over the last few years, lncRNAs have rapidly emerged as key regulators of EMT in cancer. In this review, we discuss the lncRNAs that have been associated with the EMT process in cancer and the variety of molecular mechanisms and signalling pathways through which they regulate EMT, and finally discuss how these EMT-regulating lncRNAs impact on both anti-cancer drug resistance and the cancer stem cell phenotype.

Decreased expression of LncRNA SRA1 in hepatocellular carcinoma and its clinical significance

BACKGROUND

Hepatocellular carcinoma (HCC), is an extremely aggressive malignancy with poor prognosis and high fatality rates worldwide. Accumulating evidence indicated that novel biomarkers are required to get a better understanding of the biological mechanisms of HCC. SRA1, a long non-coding RNA (lncRNA), serves as a critical regulator in several cancers. However, the association between SRA1 expression and tumorigenesis in HCC tissues remains unclear.

OBJECTIVE

In the present study, we evaluated the expression of SRA1 in HCC and its clinical association.

METHODS

The expression levels of SRA1 in 67 pairs of cancer tissues and adjacent normal tissues from HCC patients were detected using quantitative real-time PCR. Expression of SRA1 in HCC cell lines compared with normal human hepatocyte cell lines was also measured. Finally, the potential associations between its level in HCC tissues and the clinicopathological parameters were analyzed as well.

RESULTS

The results indicated that the expression levels of SRA1 in HCC were remarkably decreased, compared with matched normal tissues (P< 0.001). Levels of SRA1 in HCC cell lines were also significantly decreased than that in normal human hepatocyte cell line L-02. Additionally, the levels of SRA1 were significantly associated with tumor size (P= 0.020) and serum GLU level (P= 0.046).

CONCLUSIONS

This study highlighted that SRA1 was downregulated in HCC and might serve as a tumor suppressor in HCC, which laid a solid foundation for future research.

Long non-coding RNA HNF1A-AS1 promotes hepatocellular carcinoma cell proliferation by repressing NKD1 and P21 expression

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. Recent evidences have demonstrated that long non-coding RNAs (lncRNAs) act as key regulators of tumor development and progression including HCC. In the study, we showed that the expression level of HNF1A-AS1 was up-regulated in HCC cell lines. Furthermore, CCK-8 cell proliferation assays and cell cycle analysis showed that HNF1A-AS1 over-expression facilitated HCC cell proliferation by promoting the cell proliferation and S-phase progression, whereas HNF1A-AS1 knockdown had the opposite effect. Western-blotting analysis revealed that knockdown of HNF1A-AS1 inhibited the cycle-relative protein cyclin-D1 and PCNA expression in HCC cells. Mechanism, RNA immunoprecipitation (RIP) and Chromatin immunoprecipitation (ChIP) assays showed that by interacting with enhancer of zeste homolog 2 (EZH2), HNF1A-AS1 promoted HCC cell proliferation by repressing the NKD1 and p21 expression. These results suggested that HNF1A-AS1 may contribute to HCC progression, which may be an effective therapeutic target for patients.

The role of long non-coding RNAs in nasopharyngeal carcinoma: As systemic review

Recent development of cutting edge research found that long noncoding RNAs (lncRNAs) plays important roles in carcinogenesis and progression. In Southeast Asia and North Africa, nasopharyngeal carcinoma (NPC) is the most common aggressive squamous cell carcinoma. Nasopharyngeal carcinoma is most frequently occurring in males. However, nasopharyngeal carcinoma is caused by a combination of several factors as viral, environmental factors, and heredity. Till now, the potential pathway or mechanism of NPC is not well known. In our present review, we strongly emphasized on long noncoding RNAs (lncRNAs) and its significant role in nasopharyngeal carcinoma. It has been showed that lncRNAs regulate the development and progression of different types of cancers, including NPC. In addition, it has been found that chromatin organization, transcriptional and post-transcriptional events are regulated by lncRNAs. Our present review summarizes the roles of lncRNAs in nasopharyngeal carcinoma and provides an overview of the feasibility of lncRNAs as diagnosis, prognosis and potential treatment for NPC patients.

An Insight into the Increasing Role of LncRNAs in the Pathogenesis of Gliomas

Long non-coding RNAs (LncRNAs) are essential epigenetic regulators with critical roles in tumor initiation and malignant progression. However, the roles and mechanisms of aberrantly expressed lncRNAs in the pathogenesis of gliomas are not fully understood. With the development of deep sequencing analyses, an extensive amount of functional non-coding RNAs has been discovered in glioma tissues and cell lines. Additionally, the contributions of several lncRNAs, such as Hox transcript antisense intergenic RNA, H19 and Colorectal neoplasia differentially expressed, previously reported to be involved in other pathogenesis and processes to the oncogenesis of glioblastoma are currently addressed. Thus, lncRNAs detected in tumor tissues could serve as candidate diagnostic biomarkers and therapeutic targets for gliomas. To understand the potential function of lncRNAs in gliomas, in this review, we briefly describe the profile of lncRNAs in human glioma research and therapy. Then, we discuss the individual lncRNA that has been under intensive investigation in glioma research, and the focus is its mechanism and clinical implication.

Long non-coding RNAs act as regulators of cell autophagy in diseases (Review)

Identification of long non-coding RNAs (lncRNAs) has provided a substantial increase in our understanding of the non-coding transcriptome. Studies have revealed a crucial function of lncRNAs in the modulation of cell autophagy in vitro and in vivo, further contributing to the hallmarks of disease phenotypes. These findings have profoundly altered our understanding of disease pathobiology, and may lead to the emergence of new biological concepts underlying autophagy-associated diseases, such as the carcinomas. Studies on the molecular mechanism of the lncRNA-autophagy axis may offer additional avenues for therapeutic intervention and biomarker assessment. In this review, we discuss recent findings on the multiple molecular roles of regulatory lncRNAs in the signaling pathways of cell autophagy. The emerging knowledge in this rapidly advancing field will offer novel insights into human diseases, especially cancers.

Linc-ROR confers gemcitabine resistance to pancreatic cancer cells via inducing autophagy and modulating the miR-124/PTBP1/PKM2 axis

PURPOSE

In this study, we investigated the regulation of linc-ROR on autophagy and gemcitabine resistance of pancreatic cancer cells and further studied the underlying involvement of the miR-124/PTBP1/PKM2 axis in this regulation.

METHODS

Pancreatic cancer cell lines PANC-1 and MIAPaCa-2 cells were used as in vitro model. Autophagy was assessed by western blot of LC3 I/II and observation GFP-LC3 puncta. Cell viability was examined using CCK-8 assay. Cell apoptosis was examined by flow cytometric analysis of Annexin V/PI staining. QRT-PCR, RNA fluorescence in situ hybridization and dual luciferase assay were used to study the expression and the binding between linc-ROR and miR-124.

RESULTS

Linc-ROR siRNA significantly sensitized PANC-1 and MIAPaCa-2 cells to gemcitabine, while linc-ROR overexpression significantly reduced the sensitivity. Linc-ROR knockdown reduced basal autophagy, while linc-ROR overexpression markedly increased basal autophagy in the cells. Linc-ROR siRNA showed similar effect as 3-MA on enhancing gemcitabine-induced cell apoptosis and also reduced PKM2 expression. MiR-124 overexpression restored PKM1 and reduced PKM2 levels in the cells. In addition, miR-124 mimics also alleviated autophagy in pancreatic cancer cells. Both miR-124 mimics and PKM2 siRNA enhanced gemcitabine-induced cell apoptosis. In both pancreatic cell lines and PADC tissues, linc-ROR is negatively correlated with miR-124 expression. In addition, dual luciferase assay verified two 8mer binding sites between miR-124 and linc-ROR.

CONCLUSION

Linc-ROR confers gemcitabine resistance to pancreatic cancer cells at least partly via inducing autophagy. There is a linc-ROR/miR-124/PTBP1/PKM2 axis involved in regulation of gemcitabine resistance in pancreatic cancer cells.

MicroRNAs and long non-coding RNAs in digestive system malignancies

The mammalian transcriptome includes a large number of microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). Some studies have reported that numerous kinds of miRNAs and lncRNAs have been implicated in playing key regulatory roles in the occurrence and development of digestive system malignances. Therefore, they are closely related to the clinical diagnosis, treatment and prognosis of digestive system malignances. This review focuses on the recent progress in research of miRNAs and lncRNAs in in digestive system malignancies and discusses their epigenetics roles as oncogenes or tumor suppressors. The current and future potential clinical applications of miRNAs and lncRNAs in digestive system malignancies are also discussed, with an aim to provide new ideas and means for the diagnosis, treatment and prognosis of digestive system malignancies.