LncRNA MALAT1 promotes epithelial-to-mesenchymal transition of esophageal cancer through Ezh2-Notch1 signaling pathway

A comprehensive database of exosome molecular biomarkers and disease-gene associations

Exosomes play a crucial role in intercellular communication and can be used as biomarkers for diagnostic and therapeutic clinical applications. However, systematic studies in cancer-associated exosomal nucleic acids remain a big challenge. Here, we developed ExMdb, a comprehensive database of exosomal nucleic acid biomarkers and disease-gene associations curated from published literature and high-throughput datasets. We performed a comprehensive curation of exosome properties including 4,586 experimentally supported gene-disease associations, 13,768 diagnostic and therapeutic biomarkers, and 312,049 nucleic acid subcellular locations. To characterize expression variation of exosomal molecules and identify causal factors of complex diseases, we have also collected 164 high-throughput datasets, including bulk and single-cell RNA sequencing (scRNA-seq) data. Based on these datasets, we performed various bioinformatics and statistical analyses to support our conclusions and advance our knowledge of exosome biology. Collectively, our dataset will serve as an essential resource for investigating the regulatory mechanisms of complex diseases and improving the development of diagnostic and therapeutic biomarkers.

MALAT-1 Is a Key Regulator of Epithelial-Mesenchymal Transition in Cancer: A Potential Therapeutic Target for Metastasis

Metastasis-associated lung adenocarcinoma transcript-1 (MALAT-1) is a long intergenic non-coding RNA (lncRNA) located on chr11q13. It is overexpressed in several cancers and controls gene expression through chromatin modification, transcriptional regulation, and post-transcriptional regulation. Importantly, MALAT-1 stimulates cell proliferation, migration, and metastasis and serves a vital role in driving the epithelial-to-mesenchymal transition (EMT), subsequently acquiring cancer stem cell-like properties and developing drug resistance. MALAT-1 modulates EMT by interacting with various intracellular signaling pathways, notably the phosphoinositide 3-kinase (PI3K)/Akt and Wnt/β-catenin pathways. It also behaves like a sponge for microRNAs, preventing their interaction with target genes and promoting EMT. In addition, we have used bioinformatics online tools to highlight the disparities in the expression of MALAT-1 between normal and cancer samples using data from The Cancer Genome Atlas (TCGA). Furthermore, the intricate interplay of MALAT-1 with several essential targets of cancer progression and metastasis renders it a good candidate for therapeutic interventions. Several innovative approaches have been exploited to target MALAT-1, such as short hairpin RNAs (shRNAs), antisense oligonucleotides (ASOs), and natural products. This review emphasizes the interplay between MALAT-1 and EMT in modulating cancer metastasis, stemness, and chemoresistance in different cancers.

Advances in bi-directional relationships for EZH2 and oxidative stress

Over the past two decades, polycomb repressive complex 2(PRC2) has emerged as a vital repressive complex in overall cell fate determination. In mammals, enhancer of zeste homolog 2 (EHZ2), which is the core component of PRC2, has also been recognized as an important regulator of inflammatory, redox, tumorigenesis and damage repair signalling networks. To exert these effects, EZH2 must regulate target genes epigenetically or interact directly with other gene expression-regulating factors, such as LncRNAs and microRNAs. Our review provides a comprehensive summary of research advances, discoveries and trends regarding the regulatory mechanisms between EZH2 and reactive oxygen species (ROS). First, we outline novel findings about how EZH2 regulates the generation of ROS at the molecular level. Then, we summarize how oxidative stress controls EHZ2 alteration (upregulation, downregulation, or phosphorylation) via various molecules and signalling pathways. Finally, we address why EZH2 and oxidative stress have an undefined relationship and provide potential future research ideas.

Potential role of epithelial-mesenchymal transition induced by periodontal pathogens in oral cancer

With the increasing incidence of oral cancer in the world, it has become a hotspot to explore the pathogenesis and prevention of oral cancer. It has been proved there is a strong link between periodontal pathogens and oral cancer. However, the specific molecular and cellular pathogenic mechanisms remain to be further elucidated. Emerging evidence suggests that periodontal pathogens-induced epithelial-mesenchymal transition (EMT) is closely related to the progression of oral cancer. Cells undergoing EMT showed increased motility, aggressiveness and stemness, which provide a pro-tumour environment and promote malignant metastasis of oral cancer. Plenty of studies proposed periodontal pathogens promote carcinogenesis via EMT. In the current review, we discussed the association between the development of oral cancer and periodontal pathogens, and summarized various mechanisms of EMT caused by periodontal pathogens, which are supposed to play an important role in oral cancer, to provide targets for future research in the fight against oral cancer.

From LncRNA to metastasis: The MALAT1-EMT axis in cancer progression

Cancer is a complex disease that causes abnormal genetic changes and unchecked cellular growth. It also causes a disruption in the normal regulatory processes that leads to the creation of malignant tissue. The complex interplay of genetic, environmental, and epigenetic variables influences its etiology. Long non-coding RNAs (LncRNAs) have emerged as pivotal contributors within the intricate landscape of cancer biology, orchestrating an array of multifaceted cellular processes that substantiate the processes of carcinogenesis and metastasis. Metastasis is a crucial driver of cancer mortality. Among these, MALAT1 (Metastasis-Associated Lung Adenocarcinoma Transcript 1) has drawn a lot of interest for its function in encouraging metastasis via controlling the Epithelial-Mesenchymal Transition (EMT) procedure. MALAT1 exerts a pivotal influence on the process of EMT, thereby promoting metastasis to distant organs. The mechanistic underpinning of this phenomenon involves the orchestration of an intricate regulatory network encompassing transcription factors, signalling cascades, and genes intricately associated with the EMT process by MALAT1. Its crucial function in transforming tumor cells into an aggressive phenotype is highlighted by its capacity to influence the expression of essential EMT effectors such as N-cadherin, E-cadherin, and Snail. An understanding of the MALAT1-EMT axis provides potential therapeutic approaches for cancer intervention. Targeting MALAT1 or its downstream EMT effectors may reduce the spread of metastatic disease and improve the effectiveness of already available therapies. Understanding the MALAT1-EMT axis holds significant clinical implications. Therefore, directing attention towards MALAT1 or its downstream mediators could present innovative therapeutic strategies for mitigating metastasis and improving patient prognosis. This study highlights the importance of MALAT1 in cancer biology and its potential for cutting back on metastatic disease with novel treatment strategies.

The involvement of MALAT1-ALKBH5 signaling axis into proliferation and metastasis of human papillomavirus-positive cervical cancer

Infection with high-risk human papillomavirus (HPV), for example, with types 16 and 18, is closely associated with cervical cancer development, which continues to threaten women's health globally. Although HPV oncogenes have been recognized as the main cause of transformation of normal cervical epithelial cells, non-coding RNA could also be involved in the initiation and promotion of cervical cancer development. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a well-documented long non-coding RNA (lncRNA), has been previously reported to exert roles in HPV-positive cervical cancer; however, the detailed underlying mechanism has yet to be investigated. In the present study, high expression levels of MALAT1 in HPV-Positive Cervical Cancer cells were confirmed, and silencing MALAT1 resulted in decreased rates of cell proliferation, migration, and invasion, both in vitro and in a zebrafish xenograft tumor model. Moreover, the results obtained showed that silencing MALAT1 led to down-regulation of the N6-methyladenosine (m6A) demethylase ALKBH5 via regulating miR-141-3p expression, which caused a decrease in the expression levels of matrix metalloproteinase 2 (MMP2) and MMP9 expression, thereby suppressing cell migration and invasion. Taken together, the results obtained have suggested that the MALAT-ALKBH5 signaling axis may be activated in HPV-positive cervical cancer cells, which could contribute to cell proliferation and metastasis through the regulation of key genes, such as MMP2 or MMP9. The findings of the present study should both help to improve our understanding of the underlying tumorigenic mechanisms of HPV-positive cervical cancer and be of further use in the development of potential therapeutic drugs.

Regulation of Notch1 Signalling by Long Non-Coding RNAs in Cancers and Other Health Disorders

Notch1 signalling plays a multifaceted role in tissue development and homeostasis. Currently, due to the pivotal role of Notch1 signalling, the relationship between NOTCH1 expression and the development of health disorders is being intensively studied. Nevertheless, Notch1 signalling is not only controlled at the transcriptional level but also by a variety of post-translational events. First is the ligand-dependent mechanical activation of NOTCH receptors and then the intracellular crosstalk with other signalling molecules-among those are long non-coding RNAs (lncRNAs). In this review, we provide a detailed overview of the specific role of lncRNAs in the modulation of Notch1 signalling, from expression to activity, and their connection with the development of health disorders, especially cancers.

Long noncoding RNA MALAT1 is dynamically regulated in leader cells during collective cancer invasion

Cancer cells collectively invade using a leader-follower organization, but the regulation of leader cells during this dynamic process is poorly understood. Using a dual double-stranded locked nucleic acid (LNA) nanobiosensor that tracks long noncoding RNA (lncRNA) dynamics in live single cells, we monitored the spatiotemporal distribution of lncRNA during collective cancer invasion. We show that the lncRNA MALAT1 (metastasis-associated lung adenocarcinoma transcript 1) is dynamically regulated in the invading fronts of cancer cells and patient-derived spheroids. MALAT1 transcripts exhibit distinct abundance, diffusivity, and distribution between leader and follower cells. MALAT1 expression increases when a cancer cell becomes a leader and decreases when the collective migration process stops. Transient knockdown of MALAT1 prevents the formation of leader cells and abolishes the invasion of cancer cells. Taken together, our single-cell analysis suggests that MALAT1 is dynamically regulated in leader cells during collective cancer invasion.

Human umbilical cord mesenchymal stem cells: Heralding an effective treatment against esophageal cancer?

Esophageal cancer (EC), as one of the leading causes of cancer-associated mortality, influences a remarkable population of subjects globally and is histologically divided into two types, comprising esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (ESCC). Although several therapeutic approaches are present for EC, such as radiotherapy, chemotherapy, and surgery, these options have low success with serious side effects, for example, gastrointestinal toxicity, esophagitis, and pulmonary complications. Thus, utilizing an effective tool with low side effects is urgent. Newly, mesenchymal stem cells (MSCs) have received special interest for treating diverse diseases, such as cancer. Among different sources of MSCs, human umbilical cord MSCs have notable benefits, and reports expressed that they may be effective in EC treatment. For this purpose, in this review study, we aimed to summarize evidence regarding the effects of human umbilical cord MSCs on EC with a mechanistic insight.

LncRNA MALAT1 Regulates Hyperglycemia Induced EMT in Keratinocyte via miR-205

Epithelial-to-mesenchymal transition (EMT) is critical to cutaneous wound healing. When skin is injured, EMT activates and mobilizes keratinocytes toward the wound bed, therefore enabling re-epithelialization. This process becomes dysregulated in patients with diabetes mellitus (DM). Long non-coding RNAs (lncRNAs) regulate many biological processes. LncRNA-metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) influences numerous cellular processes, including EMT. The objective of the current study is to explore the role of MALAT1 in hyperglycemia (HG)-induced EMT. The expression of MALAT1 was found to be significantly upregulated, while the expression of miR-205 was downregulated in diabetic wounds and high-glucose-treated HaCaT cells. The initiation of EMT in HaCaT cells from hyperglycemia was confirmed by a morphological change, the increased expression of CDH2, KRT10, and ACTA2, and the downregulation of CDH1. The knockdown of MALAT1 was achieved by transfecting a small interfering RNA (SiRNA). MALAT1 and miR-205 were found to modulate HG-induced EMT. MALAT1 silencing or miR-205 overexpression appears to attenuate hyperglycemia-induced EMT. Mechanistically, MALAT1 affects HG-induced EMT through binding to miR-205 and therefore inducing ZEB1, a critical transcription factor for EMT. In summary, lncRNA MALAT1 is involved in the hyperglycemia-induced EMT of human HaCaT cells. This provides a new perspective on the pathogenesis of diabetic wounds.

Regulation of the Inflammatory Response, Proliferation, Migration, and Epithelial-Mesenchymal Transition of Human Lens Epithelial Cells by the lncRNA-MALAT1/miR-26a-5p/TET1 Signaling Axis

Background

The ocular inflammatory microenvironment has been reported to be closely associated with the occurrence and progression of highly myopic cataract (HMC). Long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) could alter the biological properties of mammalian cells by modulating the expression of inflammatory mediators; therefore, it may contribute to the development of HMC.

Objective

To investigate the function of MALAT1 in the inflammatory response, proliferation, migration, and epithelial-mesenchymal transition (EMT) of inflammatory and injured human lens epithelial cells (HLECs) and to reveal the underlying molecular signals.

Methods

Patients with HMC and age-related cataract (ARC) with an axial length of more than 26 mm were selected, and the anterior capsular tissue was obtained during cataract surgery. TNF-α (20 ng/mL) was chosen to induce inflammatory damage in HLECs to simulate the inflammatory microenvironment in HMC eyes. Specific siRNAs, inhibitors, and mimics were used to suppress or enhance the functions of MALAT1 and miR-26a-5p. RT-qPCR and Western blot analysis were performed to measure gene and protein expression, respectively.

Results

The expression of MALAT1 and the inflammatory mediators IL-6, MMP-2, and MMP-9 were significantly higher in HMC anterior capsule tissues than in ARC. TNF-α treatment increased the expression of MALAT1, while it also promoted the proliferation, migration, and EMT of HLECs. MALAT1 interference decreased the expression of IL-6 and MMP-2 and inhibited the aforementioned processes. Furthermore, MALAT1 negatively regulated the expression of miR-26a-5p and then promoted TET1 expression. TET1 was identified as a direct target of miR-26a-5p, and the promoting effect of MALAT1 on TET1 expression could be reversed by miR-26a-5p mimics.

Conclusion

The inflammatory environment and MALAT1 expression could be reciprocally induced in HLECs. MALAT1 may act as a ceRNA via the "sponge" miR-26a-5p and target TET1 to regulate the inflammatory response, proliferation, migration, and EMT processes in HLECs.

Mechanism of Extracellular Vesicle Secretion Associated with TGF-β-Dependent Inflammatory Response in the Tumor Microenvironment

Extracellular vesicles (EVs) serve as central mediators in communication between tumor and non-tumor cells. These interactions are largely dependent on the function of the endothelial barrier and the set of receptors present on its surface, as endothelial cells (ECs) are a plenteous source of EVs. The molecular basis for EV secretion and action in the tumor microenvironment (TME) has not been fully elucidated to date. Emerging evidence suggests a prominent role of inflammatory pathways in promoting tumor progression and metastasis. Although transforming growth factor β (TGF-β) is a cytokine with strong immunomodulatory and protective activity in benign and early-stage cancer cells, it plays a pro-tumorigenic role in advanced cancer cells, which is known as the "TGF-β paradox". Thus, the aim of this review is to describe the correlation between EV release, TGF-β-dependent inflammation, and dysregulation of downstream TGF-β signaling in the context of cancer development.

The Emerging Role of Long Non-Coding RNAs in Esophageal Cancer: Functions in Tumorigenesis and Clinical Implications

Esophageal cancer (EC) is one of the most common malignancies of digestive tracts with poor five-year survival rate. Hence, it is very significant to further investigate the occurrence and development mechanism of esophageal cancer, find more effective biomarkers and promote early diagnosis and effective treatment. Long non-coding RNAs (lncRNAs) are generally defined as non-protein-coding RNAs with more than 200 nucleotides in length. Existing researches have shown that lncRNAs could act as sponges, guides, scaffolds, and signal molecules to influence the oncogene or tumor suppressor expressions at transcriptional, post-transcriptional, and protein levels in crucial cellular processes. Currently, the dysregulated lncRNAs are reported to involve in the pathogenesis and progression of EC. Importantly, targeting EC-related lncRNAs through genome editing, RNA interference and molecule drugs may be one of the most potential therapeutic methods for the future EC treatment. In this review, we summarized the biological functions and molecular mechanisms of lncRNAs, including oncogenic lncRNAs and tumor suppressor lncRNAs in EC. In addition, we generalized the excellent potential lncRNA candidates for diagnosis, prognosis and therapy in EC. Finally, we discussed the current challenges and opportunities of lncRNAs for EC.

A Pleiotropic Role of Long Non-Coding RNAs in the Modulation of Wnt/β-Catenin and PI3K/Akt/mTOR Signaling Pathways in Esophageal Squamous Cell Carcinoma: Implication in Chemotherapeutic Drug Response

Despite the availability of modern techniques for the treatment of esophageal squamous cell carcinoma (ESCC), tumor recurrence and metastasis are significant challenges in clinical management. Thus, ESCC possesses a poor prognosis and low five-year overall survival rate. Notably, the origin and recurrence of the cancer phenotype are under the control of complex cancer-related signaling pathways. In this review, we provide comprehensive knowledge about long non-coding RNAs (lncRNAs) related to Wnt/β-catenin and phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway in ESCC and its implications in hindering the efficacy of chemotherapeutic drugs. We observed that a pool of lncRNAs, such as HERES, TUG1, and UCA1, associated with ESCC, directly or indirectly targets various molecules of the Wnt/β-catenin pathway and facilitates the manifestation of multiple cancer phenotypes, including proliferation, metastasis, relapse, and resistance to anticancer treatment. Additionally, several lncRNAs, such as HCP5 and PTCSC1, modulate PI3K/Akt/mTOR pathways during the ESCC pathogenesis. Furthermore, a few lncRNAs, such as AFAP1-AS1 and LINC01014, block the efficiency of chemotherapeutic drugs, including cisplatin, 5-fluorouracil, paclitaxel, and gefitinib, used for ESCC treatment. Therefore, this review may help in designing a better therapeutic strategy for ESCC patients.

Long Non-Coding RNA in Esophageal Cancer: A Review of Research Progress

In recent years, there has been significant progress in the diagnosis and treatment of esophageal cancer. However, owing to the lack of early diagnosis strategies and treatment targets, the prognosis of patients with esophageal cancer remains unsatisfactory. There is an urgent need to identify novel biomarkers and treatment targets for esophageal cancer. With the development of genomics, long-chain non-coding RNAs (LncRNAs), which were once considered transcriptional “noise,” are being identified and characterized rapidly in large numbers. Recent research shows that LncRNAs are closely related to a series of steps in tumor development and play an important regulatory role in DNA replication, transcription, and post-transcriptional regulation. The abnormal expression of LncRNAs leads to tumor cell proliferation, migration, invasion, and treatment resistance. This review focuses on the latest progress in research on the abnormal expression and functional mechanisms of LncRNAs in esophageal cancer. Further, it discusses the potential applications of these findings towards achieving an early diagnosis, improving treatment efficacy, and evaluating the prognosis of esophageal cancer.

The long and short non-coding RNAs modulating EZH2 signaling in cancer

Non-coding RNAs (ncRNAs) are a large family of RNA molecules with no capability in encoding proteins. However, they participate in developmental and biological processes and their abnormal expression affects cancer progression. These RNA molecules can function as upstream mediators of different signaling pathways and enhancer of zeste homolog 2 (EZH2) is among them. Briefly, EZH2 belongs to PRCs family and can exert functional roles in cells due to its methyltransferase activity. EZH2 affects gene expression via inducing H3K27me3. In the present review, our aim is to provide a mechanistic discussion of ncRNAs role in regulating EZH2 expression in different cancers. MiRNAs can dually induce/inhibit EZH2 in cancer cells to affect downstream targets such as Wnt, STAT3 and EMT. Furthermore, miRNAs can regulate therapy response of cancer cells via affecting EZH2 signaling. It is noteworthy that EZH2 can reduce miRNA expression by binding to promoter and exerting its methyltransferase activity. Small-interfering RNA (siRNA) and short-hairpin RNA (shRNA) are synthetic, short ncRNAs capable of reducing EZH2 expression and suppressing cancer progression. LncRNAs mainly regulate EZH2 expression via targeting miRNAs. Furthermore, lncRNAs induce EZH2 by modulating miRNA expression. Circular RNAs (CircRNAs), like lncRNAs, affect EZH2 expression via targeting miRNAs. These areas are discussed in the present review with a focus on molecular pathways leading to clinical translation.

Current insights on extracellular vesicle-mediated glioblastoma progression: Implications in drug resistance and epithelial-mesenchymal transition

BACKGROUND

Glioblastoma multiforme (GBM) is one of the most fatal tumors of the central nervous system with high rate of disease progression, diagnosis, prognosis and low survival rate. Therapeutic approaches that relied on surgical resection and chemotherapy have been unable to curb the disease progression and subsequently leading to increase in incidences of GBM reoccurrence.

SCOPE OF THE REVIEW

In the recent times, membrane-bound extracellular vesicles (EVs) have been observed as one of the key reasons for the uncontrolled growth of GBM. EVs are shown to have the potential to contribute to the disease progression via mediating drug resistance and epithelial-mesenchymal transition. The GBM-derived EVs (GDEVs) with its cargo contents act as the biological trojan horse and lead to disease progression after being received by the recipient target cells. This review article highlights the biophysical, biochemical properties of EVs, its cargo contents and its potential role in the growth and progression of GBM by altering tumour microenvironment.

MAJOR CONCLUSIONS

EVs are being explored for serving as novel disease biomarkers in a variety of cancer types such as adenocarcinoma, pancreatic cancer, color rectal cancer, gliomas and glioblastomas. Improvement in the EV isolation protocols, polymer-based separation techniques and transcriptomics, have made EVs a key diagnostic marker to unravel the progression and early GBM diagnosis. GDEVs role in tumour progression is under extensive investigations.

GENERAL SIGNIFICANCE

Attempts have been also made to discuss and compare the usage of EVs as potential therapeutic targets versus existing therapies targeting drug resistance and EMT.

Dexmedetomidine inhibits the growth and metastasis of esophageal cancer cells by down-regulation of lncRNA MALAT1

This study aims to evaluate the effect of dexmedetomidine (DEX)-on esophageal cancer (EC) via regulating long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1). The effect of DEX on MALAT1 expression and EC cell viability was detected. EC cells were divided into Blank, DEX, scrambled/MALAT1 siRNA, and DEX + control/MALAT1 groups, followed by a series of experiments including quantitative reverse-transcription polymerase chain reaction (qRT-PCR), western blotting, 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT), Annexin V-FITC/PI staining, wound healing, and Transwell assays. Additionally, mice were subjected to the subcutaneous injection of Eca109 cells transfected by control/MALAT1 activation lentiviral vector to construct EC models with the DEX treatment, and then the tumor volume and the expression of Ki-67 and active caspase-3 were determined. DEX reduced the expression of MALAT1 in EC cells in a dose-dependent manner. DEX inhibited the viability of EC cells, but increased the cell apoptosis, which, however, was reversed by MALAT1 overexpression. Moreover, MALAT1 overexpression abolished the inhibitory effect of DEX on the epithelial-mesenchymal transition (EMT) of EC cells, with enhanced migration and invasion. Furthermore, DEX succeeded in decreasing the tumor volume with the down-regulation of MALAT1. In comparison with the DEX group, mice in the DEX + MALAT1 group had larger tumors, with the up-regulation of Ki-67 and the down-regulation of active caspase-3. DEX can reduce the expression of MALAT1 in EC cells, thereby inhibiting the proliferation, invasion and migration, as well as EMT, and promoting the apoptosis of EC cells.

Sesquiterpene Lactones Attenuate Paclitaxel Resistance Via Inhibiting MALAT1/STAT3/ FUT4 Axis and P-Glycoprotein Transporters in Lung Cancer Cells

Paclitaxel resistance is a challenging factor in chemotherapy resulting in poor prognosis and cancer recurrence. Signal transducer and activator of transcription factor 3 (STAT3), a key transcription factor, performs a critical role in cancer development, cell survival and chemoresistance, while its inactivation overwhelms drug resistance in numerous cancer types including lung cancer. Additionally, the fucosyltransferase 4 (FUT4) is a crucial enzyme in post-translational modification of cell-surface proteins involved in various pathological conditions such as tumor multidrug resistance (MDR). The P-glycoprotein (P-GP) is the well-known ABC transporter member that imparts drug resistance in different cancer types, most notably paclitaxel resistance in lung cancer cells. LncRNA-MALAT1 exerts a functional role in the cancer development as well as the drug resistance and is linked with STAT3 activation and activity of FUT4. Moreover, STAT3-mediated induction of P-GP is well-documented. Natural compounds of Sesquiterpene Lactone (SL) family are well-known for their anticancer properties with particular emphasis over STAT3 inhibitory capabilities. In this study, we explored the positive correlation of MALAT1 with STAT3 and FUT4 activity in paclitaxel resistant A549 (A549/T) lung cancer cells. Additionally, we investigated the anticancer activity of two well-known members of SLs, alantolactone (ALT) and Brevilin A (Brv-A), in A549/T lung cancer cells. ALT and Brv-A induced apoptosis in A549/T cells. Furthermore, these two natural SLs suppressed MALAT1 expression, STAT3 activation, and FUT4 and P-GP expression which are the hallmarks for paclitaxel resistance in A549 lung cancer cells. The inhibition of MALAT1 enhanced the competence of these SLs members significantly, which accounted for the growth inhibition as well as anti-migratory and anti-invasive effects of ALT and Brv-A. These findings suggest SLs to be the promising agents for overcoming paclitaxel resistance in A549 lung cancer cells.

The Roles and Mechanisms of lncRNAs in Liver Fibrosis

Long non-coding RNAs (lncRNAs) can potentially regulate all aspects of cellular activity including differentiation and development, metabolism, proliferation, apoptosis, and activation, and benefited from advances in transcriptomic and genomic research techniques and database management technologies, its functions and mechanisms in physiological and pathological states have been widely reported. Liver fibrosis is typically characterized by a reversible wound healing response, often accompanied by an excessive accumulation of extracellular matrix. In recent years, a range of lncRNAs have been investigated and found to be involved in several cellular-level regulatory processes as competing endogenous RNAs (ceRNAs) that play an important role in the development of liver fibrosis. A variety of lncRNAs have also been shown to contribute to the altered cell cycle, proliferation profile associated with the accelerated development of liver fibrosis. This review aims to discuss the functions and mechanisms of lncRNAs in the development and regression of liver fibrosis, to explore the major lncRNAs involved in the signaling pathways regulating liver fibrosis, to elucidate the mechanisms mediated by lncRNA dysregulation and to provide new diagnostic and therapeutic strategies for liver fibrosis.

LncRNA MALAT1 Modulates TGF-β1-Induced EMT in Keratinocyte

One of the major complications in diabetes is impaired wound healing. Unfortunately, effective therapies are currently lacking. Epithelial to mesenchymal transition (EMT) is a critical process involved in cutaneous wound healing. In response to injury, EMT is required to activate and mobilize stationary keratinocytes in the skin toward the wound bed, which allows for re-epithelialization. This process is stalled in diabetic wounds. In this study, we investigate the role of long non-coding RNA (lncRNA), MALAT1, in transforming growth factor beta 1(TGF-β1)-induced EMT of human keratinocyte (HaCaT) cells. Initially, we detected MALAT1 and TGF-β1 expression in non-diabetic and diabetic wounds and found that these expression are significantly up-regulated in diabetic wounds. Then, HaCaT cells were cultured and exposed to TGF-β1. The EMT of HaCaT cells were confirmed by the increased expression of CDH2, KRT10, and ACTA2, in addition to the down-regulation of CDH1. Knockdown of MALAT1 was achieved by transfecting a small interfering RNA (SiRNA). MALAT1 silencing attenuates TGFβ1-induced EMT. Mechanistically, MALAT1 is involved in TGF-β1 mediated EMT through significantly induced ZEB1 expression, a critical transcription factor for EMT. In summary, lncRNA MALAT1 is involved in TGFβ1-induced EMT of human HaCaT cells and provides new understanding for the pathogenesis of diabetic wounds.

Association of MALAT1 and PVT1 Variants, Expression Profiles and Target miRNA-101 and miRNA-186 with Colorectal Cancer: Correlation with Epithelial-Mesenchymal Transition

The influence of PVT1 and MALAT1 variants on colorectal cancer (CRC) susceptibility and their impact on PVT1/miRNA-186/epithelial-mesenchymal transition (EMT) and MALAT1/miRNA-101/EMT axes in CRC are unknown. We investigated the influence of PVT1 rs13255292 and MALAT1 rs3200401 on the risk of CRC and adenomatous polyps (AP), their impact on the long noncoding RNAs PVT1 and MALAT1 expression and their target miRNA-186, miRNA-101/E-cadherin pathways, along with their potential as early CRC biomarkers. Overall, 280 individuals were recruited: 140 patients with CRC, 40 patients with AP, and 100 healthy volunteers. Genotyping and serum expression profiles were assessed using qPCR. The EMT biomarker, E-cadherin, was measured by ELISA. rs3200401 was associated with increased CRC risk, whereas rs13255292 was protective. Serum PVT1 and MALAT1 were upregulated in CRC and AP patients versus healthy controls, whereas, miRNA-186, miRNA-101 and E-cadherin were downregulated in CRC versus non-CRC groups. MALAT1 showed superior diagnostic potential for CRC and predicted CRC risk among non-CRC groups in the multivariate logistic analysis. PVT1, MALAT1, miRNA-186 and miRNA-101 levels were correlated with E-cadherin, tumor stage, lymph node and distant metastasis. E-cadherin was lost in metastatic vs. non-metastatic CRC. rs3200401CC genotype carriers showed higher E-cadherin levels than CC + CT carriers. rs3200401 was correlated with lymph node status. For the first time, rs13255292 and rs3200401 are potential genetic CRC predisposition markers, with rs3200401 possibly impacting the EMT process. Serum PVT1, MALAT1, miRNA-186 and miRNA-101 are novel non-invasive diagnostic biomarkers that could improve the clinical outcome of CRC.

Oncogenic microRNA-301b regulates tumor repressor dystrobrevin alpha to facilitate cell growth, invasion and migration in esophageal cancer

BACKGROUND

Esophageal cancer (EC) ranks the eighth in morbidity and the sixth in mortality around the whole world, which is an aggressive malignancy. To authenticate potential therapeutic targets for EC is therefore imperative. Although miR-301b might display changed expression in esophageal adenocarcinoma by utilizing Taqman miRNA profiling analysis, much less is known about the impact of miR-301b in EC.

METHODS AND RESULTS

By analyzing the data of 187 cancer tissues and 13 normal samples from TCGA database, we discovered that miR-301b was highly expressed in EC tissues. Then, RT-qPCR determined that miR-301b was up-regulated in EC cell lines (ECA109, JAR, TE-1 and OE33). Besides, miR-301b expression level was higher in ESCC cell line-TE-1 cells and lower in ESCC cell line-ECA109 cells compared to other EC cell lines. Hence, ECA109 cell line was used to up-regulate miR-301b expression while TE-1 cell line was applied to down-regulate miR-301b expression in the subsequent experiments. Additionally, OE33, as an ECA cell line, was applied to upregulate miR-301b expression to reflect the influence of miR-301b overexpression on EC progression. More interestingly, miR-301b appeared to act as a promoting effect on the proliferation of EC cells, which was tested by CCK8. Dystrobrevin alpha (DTNA) was a targeting gene of miR-301b, which was predicted by the websites of miRanda, miRWalk and TargetScan. Additionally, DTNA was low expressed in EC tissues and was an independent predictor of EC. Meanwhile, the low expression of DTNA was related to worse overall survival in EC patients. The Pearson correlation coefficient analyzed that DTNA expression was negatively correlated with miR-301b. Furthermore, RT-qPCR and western blotting assays ulteriorly indicated that DTNA was negatively modulated by miR-301b. The facilitating impact of miR-301b re-expression on ECA109 and OE33 cell growth, invasion and migration was receded by DTNA over-expression, whilst the repressive effect of miR-301b ablation on TE-1 cell growth, invasion and migration was inversed by DTNA silencing. Overexpression of miR-301b accelerated EC cell growth, migration and invasion through targeting DTNA.

CONCLUSIONS

Above all, we concluded that miR-301b was concerned with the progression of EC via regulating DTNA, suggesting that miR-301b and its target gene, DTNA, might serve as predictive biomarkers for EC therapy.

The Impact of Non-coding RNAs in the Epithelial to Mesenchymal Transition

Epithelial to mesenchymal transition (EMT) is a course of action that enables a polarized epithelial cell to undertake numerous biochemical alterations that allow it to adopt features of mesenchymal cells such as high migratory ability, invasive properties, resistance to apoptosis, and importantly higher-order formation of extracellular matrix elements. EMT has important roles in implantation and gastrulation of the embryo, inflammatory reactions and fibrosis, and transformation of cancer cells, their invasiveness and metastatic ability. Regarding the importance of EMT in the invasive progression of cancer, this process has been well studies in in this context. Non-coding RNAs (ncRNAs) have been shown to exert critical function in the regulation of cellular processes that are involved in the EMT. These processes include regulation of some transcription factors namely SNAI1 and SNAI2, ZEB1 and ZEB2, Twist, and E12/E47, modulation of chromatin configuration, alternative splicing, and protein stability and subcellular location of proteins. In the present paper, we describe the influence of ncRNAs including microRNAs and long non-coding RNAs in the EMT process and their application as biomarkers for this process and cancer progression and their potential as therapeutic targets.

Pathways and role of MALAT1 in esophageal and gastric cancer

Esophageal cancer (EC) and gastric cancer (GC) often have an unfavorable prognosis. Therefore, research is being conducted to identify the molecular mechanisms underlying the tumorigenesis and progression of GC and EC, and to indicate novel therapeutic targets and clinically applicable biomarkers. The dysregulations and roles of long non-coding RNAs (lncRNAs) have been widely reported, and current published literature has shown that lncRNAs play important regulatory roles in the carcinogenesis and progression of EC and GC. The lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been investigated in a number of studies with regard to its pathogenic pathways and association with the prognosis of gastric and esophageal malignancies. As literature on the topic of MALAT1 in EC and GC continues to emerge, the present review aims to summarize all current knowledge on the association between MALAT1 expression and esophagogastric malignancies and to describe the pathogenic pathways and possible prognostic role of MALAT1 in esophagogastric cancer. As research studies on MALAT1 pathways in esophagogastric malignancies are ongoing, new possibilities for the diagnosis, prognosis and therapy of GC and EC are likely to be identified.

lncRNA MALAT1 Regulates Mouse Granulosa Cell Apoptosis and 17β-Estradiol Synthesis via Regulating miR-205/CREB1 Axis

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a known long noncoding RNA, was reported to play a crucial role in follicular growth and ovarian disease. However, the physiological function of MALAT1 in mouse granulosa cells (mGCs) remains largely unclear. The aims of this study were to determine the biological function and molecular mechanism of MALAT1 in mGCs. We knocked down MALAT1 in mGCs by using siRNA against MALAT1. We found that knockdown of MALAT1 promoted apoptosis and caspase-3/9 activities in mGCs. Enzyme-linked immunosorbent assay demonstrated that knockdown of MALAT1 significantly decreased the production of estradiol (E2) and progesterone (P4) in mGCs. Mechanistically, MALAT1 serves as a competing endogenous RNA (ceRNA) to sponge microRNA-205 (miR-205), thereby facilitating its downstream target of cyclic AMP response element- (CRE-) binding protein 1 (CREB1). Furthermore, CREB1 overexpression or miR-205 downregulation partially recovered the effect of MALAT1 depletion in mGCs. In summary, these findings suggested that MALAT1 regulated apoptosis and estradiol synthesis of mGCs through the miR-205/CREB1 axis.

LncRNA GIHCG Promotes the Development of Esophageal Cancer by Modulating miR-29b-3p/ANO1 Axis

Background

Esophageal cancer is one of the most frequent cancers with a higher mortality worldwide. Although many long non-coding RNAs (LncRNAs) are reported to play important roles in the progression of esophageal cancer, the function of lncRNA GIHCG in esophageal cancer remains unclear.

Methods

The expression of GIHCG in esophageal cancer tissues and cancer cell lines was detected by qRT-PCR. Cell proliferation was evaluated by Cell Counting Kit-8 (CCK-8) assay, EdU staining assay and colony formation assay. Cell invasion and migration were measured by transwell assay. Cell apoptosis was detected by a flow cytometer. Luciferase reporter assay and RIP assay were used to determine the interaction between GIHCG and miR-29b-3p, and their subsequent regulation of anoctamin 1 (ANO1). The expression of ANO1 in esophageal cancer tissues and cell lines was detected by Western blot. The effect of GIHCG/miR-29b-3p in tumor formation was assessed by the xenograft nude mice model in vivo.

Results

GIHCG was significantly upregulated in esophageal cancer tissues and relevant cancer cell lines. Downregulation of GIHCG significantly inhibited the growth, colony formation, invasion, migration and induced apoptosis of esophageal cancer cells in vitro. Bioinformatic analysis and RIP assay determined that GIHCG was a sponge of miR-29b-3p, and ANO1 was a direct target of miR-29b-3p. Moreover, functional experiments showed that GIHCG upregulated ANO1 expression by directly sponging miR-29b-3p. Furthermore, in vivo experiment revealed that knockdown of GIHCG significantly inhibited tumor growth in nude mice.

Conclusion

Our study revealed that lncRNA GIHCG promoted the progression of esophageal cancer by targeting the miR-29b-3p/ANO1 axis, suggesting that GIHCG might be a novel therapeutic target for esophageal cancer.

Identifying an Eight-Gene Signature to Optimize Overall Survival Prediction of Esophageal Adenocarcinoma Using Bioinformatics Analysis of ceRNA Network

Background and Aims

Esophageal adenocarcinoma (EAC) patients usually have a poor prognosis without early diagnosis. In this study, we aimed to identify a novel signature to improve the prediction of overall survival (OS) in EAC.

Methods

Eighty-one and 68 samples from The Cancer Genome Atlas (TCGA) and GSE19417 dataset were included for discovery and survival validation, respectively. In the TCGA cohort, a total of 1,811 DEmRNAs, 1,096 DElncRNAs, and 31 DEmiRNAs were identified between EAC and normal esophagus tissues. A mRNA–miRNA–lncRNA ceRNA network of EAC was established, which consisted of 94 DEmRNAs, 13 DEmiRNAs, and 46 DElncRNAs.

Results

In this study, we identified eight genes (UBE2B, LAMP2, B3GNT2, TAF9B, EFNA1, PHF8, PIGA, and NEURL1) which were related to survival in EAC. The independent external microarray data from the Gene Expression Omnibus (GEO) was used to validate these candidate genes. The prognostic ability of the signature was also validated in EAC patients in our hospital. Patients assigned to the high-risk group had a poor overall survival rate compared with the low-risk.

Conclusion

The current study provides novel insights into the mRNA-related ceRNA network in EAC and the eight mRNA biomarkers may be independent prognostic signatures in predicting the survival of EAC patients.

Metabolic Reprogramming by Malat1 Depletion in Prostate Cancer

Simple Summary

Prostate cancer (PCa) is one of the most common cancers in developed countries, being the second leading cause of cancer death among men. Surgery is the primary therapeutic option, but about one-third of patients develop a recurrence within ten years, for which successful therapy is unavailable. Based on these observations, it has become urgent to develop novel molecular tools for predicting clinical outcome. Here, we focus on one of the best characterized cancer-associated long non-coding transcripts, namely metastasis-associated lung adenocarcinoma transcript 1 (MALAT1). This study highlighted a novel role for MALAT1 as a controller of prostate cancer metabolism. MALAT1 silencing caused a metabolic rewire in both experimental models adopted, prostate cancer cell lines, and organotypic slice cultures derived from surgical specimens. PCa cells upon MALAT1 silencing revert their phenotype towards glycolysis, which is characteristic of normal prostate cells. In this regard, MALAT1 targeting may represent a promising diagnostic tool and a novel therapeutic option.

Abstract

The lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) promotes growth and progression in prostate cancer (PCa); however, little is known about its possible impact in PCa metabolism. The aim of this work has been the assessment of the metabolic reprogramming associated with MALAT1 silencing in human PCa cells and in an ex vivo model of organotypic slice cultures (OSCs). Cultured cells and OSCs derived from primary tumors were transfected with MALAT1 specific gapmers. Cell growth and survival, gene profiling, and evaluation of targeted metabolites and metabolic enzymes were assessed. Computational analysis was made considering expression changes occurring in metabolic markers following MALAT1 targeting in cultured OSCs. MALAT1 silencing reduced expression of some metabolic enzymes, including malic enzyme 3, pyruvate dehydrogenase kinases 1 and 3, and choline kinase A. Consequently, PCa metabolism switched toward a glycolytic phenotype characterized by increased lactate production paralleled by growth arrest and cell death. Conversely, the function of mitochondrial succinate dehydrogenase and the expression of oxidative phosphorylation enzymes were markedly reduced. A similar effect was observed in OSCs. Based on this, a predictive algorithm was developed aimed to predict tumor recurrence in a subset of patients. MALAT1 targeting by gapmer delivery restored normal metabolic energy pathway in PCa cells and OSCs.

LINC00152 upregulates ZEB1 expression and enhances epithelial-mesenchymal transition and oxaliplatin resistance in esophageal cancer by interacting with EZH2

BACKGROUND

Expression of the long non-coding mRNA LINC00152 has been reported to correlate with cancer cell resistance to oxaliplatin (L-OHP). However, little is known regarding the molecular mechanism of LINC00152 in esophageal cancer (EC). Hence, we intended to characterize the role of LINC00152 in EC, with a special focus on epithelial-mesenchymal transition (EMT) and L-OHP resistance.

METHODS

We collected EC tissues and identified EC cell lines with higher L-OHP resistance, and then characterized expression patterns of LINC00152, Zeste Homologue 2 (EZH2), Zinc finger e-box binding homeobox (ZEB1) and EMT-related genes using RT-qPCR and Western blot analysis. Furthermore, their functional significance was identified by gain and loss-of-function experiments. The relationship among LINC00152, EZH2 and ZEB1 was examined using RIP, RNA pull-down and ChIP assays. Additionally, resistance of EC cells to L-OHP was reflected by CCK-8 assay to detect cell viability. Animal experiments were also conducted to detect the effects of the LINC00152/EZH2/ZEB1 on EMT and L-OHP resistance.

RESULTS

LINC00152, EZH2 and ZEB1 were highly expressed in EC tissues and Kyse-150/TE-1 cells. As revealed by assays in vitro and in vivo, LINC00152 positively regulated ZEB1 expression through interaction with EZH2 to enhance EMT and L-OHP resistance in EC cells. In contrast, silencing of LINC00152 contributed to attenuated EMT and drug resistance of EC cells to L-OHP.

CONCLUSIONS

Our study demonstrates that LINC00152/EZH2/ZEB1 axis can regulate EMT and resistance of EC cells to L-OHP, thus presenting a potential therapeutic target for EC treatment.

Downregulation of long noncoding RNA SNHG14 suppresses cell proliferation and invasion by regulating EZH2 in pancreatic ductal adenocarcinoma (PDAC)

BACKGROUNDS

Previous studies have showed that long non-coding RNAs (lncRNAs) are critical regulators in many cancers. The aim of this study is to investigate the clinical role and functional effects of long non-coding RNA SNHG14 in pancreatic ductal adenocarcinoma (PDAC).

METHODS

The expression of SNHG14 in 58 pairs of pancreatic cancer tissues and adjacent normal tissues was detected by quantitative real-time PCR (qRT-PCR) analysis. The correlations between SNHG14 expression and PDAC patients' clinicopathological characteristics and prognosis were statistically assessed. Cell counting kit-8 (CCK8) and transwell cell invasion assays were employed to detect the capacities of cell proliferation and cell invasion. The western blot analysis was used to detected the expression of E-cadherin and Vimentin.

RESULTS

In the study, we found that SNHG14 expression was higher in PDAC tissue compared to adjacent normal tissues by qRT-PCR analysis. Higher SNHG14 expression was significantly associated with advanced TNM stage and positive lymph node metastasis in PDAC patients. Furthermore, we demonstrated that higher SNHG14 expression acted as a poor predictor in PDAC patients compared with lower SNHG14 expression. Moreover, we showed that higher SNHG14 expression promoted cell proliferation, cell colony formation and cell invasion ability in PDAC. Upregulation of SNHG14 expression promoted cell invasion by affecting E-cadherin expression via interacting with EZH2.

CONCLUSIONS

Thus, these results indicated that SNHG14 expression acts as a prognostic maker for PDAC and potential target of PDAC treatment.

Regulatory Networks of LncRNA MALAT-1 in Cancer

Long noncoding (lnc)RNAs are a group of RNAs with a length greater than 200 nt that do not encode a protein but play an essential role in regulating the expression of target genes in normal biological contexts as well as pathologic processes including tumorigenesis. The lncRNA metastasis-associated lung adenocarcinoma transcript (MALAT)-1 has been widely studied in cancer. In this review, we describe the known functions of MALAT-1; its mechanisms of action; and associated signaling pathways and their clinical significance in different cancers. In most malignancies, including lung, colorectal, thyroid, and other cancers, MALAT-1 functions as an oncogene and is upregulated in tumors and tumor cell lines. MALAT-1 has a distinct mechanism of action in each cancer type and is thus at the center of large gene regulatory networks. Dysregulation of MALAT-1 affects cellular processes such as alternative splicing, epithelial–mesenchymal transition, apoptosis, and autophagy, which ultimately results in the abnormal cell proliferation, invasion, and migration that characterize cancers. In other malignancies, such as glioma and endometrial carcinoma, MALAT-1 functions as a tumor suppressor and thus forms additional regulatory networks. The current evidence indicates that MALAT-1 and its associated signaling pathways can serve as diagnostic or prognostic biomarker or therapeutic target in the treatment of many cancers.

The mechanisms of lncRNA Tug1 in islet dysfunction in a mouse model of intrauterine growth retardation

Taurine upregulated gene 1 (Tug1) is a novel lncRNA that participates in growth, and the abnormal expression of Tug1 related to mouse islet cell dysfunction. A recent study revealed that intrauterine growth retardation (IUGR) related to the pathogenesis of diabetes. Here, we aimed to explore the role and mechanism of Tug1 in IUGR-mediated islet dysfunction. We observed that newborn IUGR mice had lower body and pancreas weight and smaller islets than newborn control mice. After IUGR mice were given a normal diet, they showed catch-up growth and abnormal glucose tolerance; however, the pancreas/body weight ratio remained low. Blood glucose, serum insulin and related gene expression showed mild recovery after overexpression of Tug1 in IUGR mice. Furthermore, Tug1 was enriched in the nuclei of MIN6 cells. Using RIP and CHIP analyses we found that Tug1 could regulate Hes1 expression by binding to EZH2 to affect insulin synthesis in MIN6 cells. These findings indicate that lncRNA Tug1 could regulate the expression of Hes1 via EZH2-driven H3K27 methylation and affect insulin production. SIGNIFICANCE OF THE STUDY: This study suggests Tug1 as a novel biomarker, as it was shown to regulate β cell function and is worthy of further investigation due to its potential for diabetes treatment.

Suppression of long non-coding RNA MALAT1 inhibits survival and metastasis of esophagus cancer cells by sponging miR-1-3p/CORO1C/TPM3 axis

Esophageal cancer (EC) is a malignancy causing lots of mortality worldwide. Long non-coding RNAs (lncRNAs) are involved in the progression of multiple cancer types. The present study aimed to explore the function and associated mechanisms of lncRNA metastasis-associated lung adenocarcinoma transcript1 (MALAT1) in EC development by focusing on its interaction with miR-1-3p. The levels of MALAT1 and miR-1-3p were investigated in clinical EC specimens. Then, the expression of MALAT1 was knocked down in EC cell lines, and the effects of MALAT1 inhibition on the viability, migration, and invasion, and miR-1-3p/Coronin-1C (CORO1C)/Tropomyosin3 (TPM3) axis in EC cells were detected. The interaction between MALAT1 and miR-1-3p in the progression of EC was further determined by suppressing the expression of miR-1-3p in MALAT1 inhibition cells. The results were further verified with EC xenograft mice model. MALAT1 level was downregulated, while miR-1-3p level was upregulated in EC specimens. The inhibition of MALAT1 suppressed the viability, migration, and invasion in EC cell lines. The changes in phenotypes of EC cells were associated with the upregulation of miR-1-3p level and inhibition of CORO1C/TPM3 activity. Furthermore, the results of dual-luciferase assay showed the direct binding of MALAT1 to the seed sequence of miR-1-3p. The suppressed level of miR-1-3p not only induced the activity of CORO1C/TPM3 signaling, but also upregulated MALAT1 expression, indicating the reciprocal regulation between the two factors. The inhibition of MALAT1 also inhibited tumor growth and epithelial-mesenchymal transition (EMT) in mice model, which was reversed by miR-1-3p inhibition. Collectively, MALAT1 was important to the survival and metastasis of EC cells by sponging miR-1-3p.

Increased Level of Long Non-Coding RNA MALAT1 is a Common Feature of Amoeboid Invasion

The ability of cancer cells to adopt various migration modes (the plasticity of cancer cell invasiveness) is a substantive obstacle in the treatment of metastasis, yet still an incompletely understood process. We performed a comparison of publicly available transcriptomic datasets from various cell types undergoing a switch between the mesenchymal and amoeboid migration modes. Strikingly, lncRNA MALAT1 (metastasis-associated lung adenocarcinoma transcript 1) was one of three genes that were found upregulated in all amoeboid cells analyzed. Accordingly, downregulation of MALAT1 in predominantly amoeboid cell lines A375m2 and A2058 resulted in decrease of active RhoA (Ras homolog family member A) and was accompanied by the amoeboid-mesenchymal transition in A375m2 cells. Moreover, MALAT1 downregulation in amoeboid cells led to increased cell proliferation. Our work is the first to address the role of MALAT1 in MAT/AMT (mesenchymal to amoeboid transition/amoeboid to mesenchymal transition) and suggests that increased MALAT1 expression is a common feature of amoeboid cells.

LncRNA GAS5 enhanced the killing effect of NK cell on liver cancer through regulating miR-544/RUNX3

This study aimed to explore the role of lncRNA GAS5 in the regulation of the killing effect of NK cells on liver cancer. Compared with a control group, lncRNA GAS5, RUNX3, and NCR1 were down-regulated in NK cells of patients with liver cancer, whereas miR-544 expression was up-regulated in NK cells of patients with liver cancer. Activated NK cells had higher IFN-γ level. Knockdown of GAS5 in activated NK cells decreased IFN-γ secretion, NK cell cytotoxicity, the percentage of CD107a+ NK cells, and the apoptosis rate of HepG2 and Huh7 cells. We also proved the interaction of GAS5 and miR-544, and the negative regulation role of GAS5 on miR-544. GAS5 overexpression in activated NK cells increased RUNX3 expression, IFN-γ secretion, the NK cell cytotoxicity, the percentage of CD107a+ NK cells, and the apoptosis rate of HepG2 cells, while miR-544 mimic abolished the promotion effect of GAS5 overexpression. Finally, in vivo experiments indicated an inhibition effect of GAS5 in tumor growth. LncRNA GAS5 overexpression enhances the killing effect of NK cell on liver cancer through regulating miR-544/RUNX3.

[Role of Circular RNA in Diagnosis, Development and Durg Resistance of Lung Cancer]

肺癌在全球范围内的致死率一直居高不下。近年来针对多种分子分型的靶向药物已成为中晚期肺癌治疗的新有效手段，但是肺癌在早期诊断以及长期有效的治疗上仍然面临着严峻的挑战。环状RNA（circular RNA, circRNA）是一类具有环形结构的独特RNA分子，具有优异的稳定性以及表达特异性。越来越多的研究发现circRNA在肿瘤中表达异常，这种异常表达不仅与肿瘤的恶性相关，同时可以参与调控肿瘤进展，为肿瘤的诊断与治疗提供了新的思路。因此，本文就circRNA在肺癌中的表达、诊断、预后价值以及发生发展机制展开综述，以期为肺癌的早期诊断与治疗寻找新的靶点。

EZH2 abnormalities in lymphoid malignancies: underlying mechanisms and therapeutic implications

EZH2 is the catalytic subunit of the polycomb repressive complex 2 (PRC2), which along with other PRC2 components mediates gene expression suppression via the methylation of Histone H3 at lysine 27. Recent studies have revealed a dichotomous role of EZH2 in physiology and in the pathogenesis of cancer. While it plays an essential role in the development of the lymphoid system, its deregulation, whether due to genetic or non-genetic causes, promotes B cell- and T cell-related lymphoma or leukemia. These findings triggered a boom in the development of therapeutic EZH2 inhibitors in recent years. Here, we discuss physiologic and pathogenic function of EZH2 in lymphoid context, various internal causes of EZH2 aberrance and how EZH2 modulates lymphomagenesis through epigenetic silencing, post-translational modifications (PTMs), orchestrating with surrounding tumor micro-environment and associating with RNA or viral partners. We also summarize different strategies to directly inhibit PRC2-EZH2 or to intervene EZH2 upstream signaling.

Metastasis Associated Lung Adenocarcinoma Transcript 1: An update on expression pattern and functions in carcinogenesis

The Metastasis Associated Lung Adenocarcinoma Transcript 1 (MALAT1) is among long non-coding RNAs (lncRNAs) which has disapproved the old term of "junk DNA" which was used for majority of human genome which are not transcribed to proteins. An extensive portion of literature points to the fundamental role of this lncRNA in tumorigenesis process of diverse cancers ranging from solid tumors to leukemia. Being firstly identified in lung cancer, it has prognostic and diagnostic values in several cancer types. Consistent with the proposed oncogenic roles for this lncRNA, most of studies have shown up-regulation of MALAT1 in malignant tissues compared with non-malignant/normal tissues of the same source. However, few studies have shown down-regulation of MALAT1 in breast cancer, endometrial cancer, colorectal cancer and glioma. In the current study, we have conducted a comprehensive literature search and provided an up-date on the role of MALAT1 in cancer biology. Our investigation underscores a potential role as a diagnostic/prognostic marker and a putative therapeutic target for MALAT1.

Expression and Clinical Significance of Translation Regulatory Long Non-Coding RNA 1 (TRERNA1) in Ependymomas

Long noncoding RNAs (lncRNA) have emerged as vital molecules governing epithelial-to-mesenchymal transition (EMT) in cancers. Translation regulatory RNA 1 (TRERNA1) is one such lncRNA known to enhance the transcriptional activity of the EMT-transcription factor, Snail. We have previously demonstrated differential upregulation of EMT-transcription factors and cadherin switching across various clinico-pathologic-molecular subclasses of ependymomas (EPN). With an aim to analyze the correlation between the expression of TRERNA1 in EPNs, we performed gene expression analysis for TRERNA1 on 75 Grade II/III EPNs and correlated with tumor site, C11orf95-RELA fusions, age, MIB-1 proliferative indices, and outcome wherever available. Upregulation of gene expression levels of TRERNA1 was seen in intracranial EPNs, with highest expression levels in pediatric posterior fossa EPNs. High TRERNA1 expression was found associated with higher proliferative indices (p = 0.034) and shorter progression free survival (p = 0.002). Our study, for the first time, demonstrates an association between TRERNA1 expressions and pediatric posterior fossa EPNs. Further in-vivo and in-vitro studies are required to confirm these findings and evaluate TRERNA1 as a novel biomarker and potential therapeutic target in childhood PF-EPNs.

The Dark That Matters: Long Non-coding RNAs as Master Regulators of Cellular Metabolism in Non-communicable Diseases

Non-coding RNAs are pivotal for many cellular functions, such as splicing, gene regulation, chromosome structure, and hormone-like activity. Here, we will report about the biology and the general molecular mechanisms associated with long non-coding RNAs (lncRNAs), a class of >200 nucleotides-long ribonucleic acid sequences, and their role in chronic non-transmissible diseases. In particular, we will summarize knowledge about some of the best-characterized lncRNAs, such as H19 and MALAT1, and how they regulate carbohydrate and lipid metabolism as well as protein synthesis and degradation. Evidence is discussed about how lncRNAs expression might affect cellular and organismal metabolism and whether their modulation could provide ground for the development of innovative treatments.

LncRNA H19 promotes epithelial mesenchymal transition and metastasis of esophageal cancer via STAT3/EZH2 axis

BACKGROUND

Long non-coding RNA H19 (lncRNA H19) has been widely reported in esophageal cancer (EC), and previous study had found that lncRNAH19 was up-regulated in EC and promoted cell proliferation and metastasis. However, the mechanism still needs further studied.

METHODS

Levels of lncRNA H19 were analyzed by qRT-PCR in matched samples from 30 patients. Expression levels of lncRNA H19, let-7, STAT3 and EZH2 were additionally identified by qRT-PCR and western blotting in five EC cell lines. The effects of lncRNA H19 on cell proliferation, migration, invasion and apoptosis in cell lines were performed by MTT assay, colony formation assay, Transwell assay and flow cytometry in vitro, and tumor formation was detected by xenograft nude mice model in vivo. The expression level of STAT3, EZH2, β-catenin, and EMT and metastasis related molecules such as E-cadherin, N-cadherin, Snail-1 and MMP-9 was assessed by qRT-PCR and western blotting. Finally, luciferase reporter assay and RIP assay were used to verify the interaction between lncRNA H19 and let-7c, and their subsequent regulation of STAT3.

RESULTS

Knockdown of lncRNA H19 repressed cell proliferation, migration and invasion as well as EMT and metastasis via STAT3-EZH2-β-catenin pathway, while lncRNA H19 regulated STAT3 negatively regulated let-7c in EC cell lines.

CONCLUSIONS

lncRNA H19 facilitates EMT and metastasis of EC through let-7c/STAT3/EZH2/β-catenin axis.

Long Noncoding RNA MALAT1 Acts as a Competing Endogenous RNA to Regulate TGF-β2 Induced Epithelial-Mesenchymal Transition of Lens Epithelial Cells by a MicroRNA-26a-Dependent Mechanism

The aim of the present study was to characterize whether the long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1)/miR-26a/Smad4 axis is involved in epithelial–mesenchymal transition (EMT) of lens epithelial cells (LECs). Primary human LECs were separated and cultured. Microarray analysis showed that a total of 568 lncRNAs are differentially expressed in primary HLECs in the presence of TGF-β2 and MALAT1 is mostly significantly dysregulated lncRNAs, which is increased by nearly 17-fold. In addition, upregulation of MALAT1 and downregulation of miR-26a were detected in human posterior capsule opacification (PCO) attached LECs and the LECs obtained from patients with anterior polar cataracts by quantitative RT-PCR (qRT-PCR). Next, our results showed that TGF-β2 induces overexpression of EMT markers in primary HLECs via a MALAT1-dependent mechanism. The mechanism is that MALAT1 negatively regulates miR-26a and miR-26a directly targets Smad4 by luciferase reporter assays and RNA-binding protein immunoprecipitation assay. In summary, TGF-β2 induces MALAT1 overexpression, which in turn MALAT1 acts as a ceRNA targeting Smad4 by binding miR-26a and promotes the progression of EMT of LECs.

Long non-coding RNAs in esophageal cancer: molecular mechanisms, functions, and potential applications

Esophageal cancer (EC) is the sixth leading cause of cancer-related death worldwide. The lack of early diagnostic biomarkers and effective prognostic indicators for metastasis and recurrence has resulted in the poor prognosis of EC. In addition, the underlying molecular mechanisms of EC development have yet to be elucidated. Accumulating evidence has demonstrated that lncRNAs play a vital role in the pathological progression of EC. LncRNAs may regulate gene expression through the recruitment of histone-modifying complexes to the chromatin and through interactions with RNAs or proteins. Recent evidence has demonstrated that the dysregulation of lncRNAs plays important roles in the proliferation, metastasis, invasion, angiogenesis, apoptosis, chemoradiotherapy resistance, and stemness of EC, which suggests potential clinical implications. In this review, we highlight the emerging roles and regulatory mechanisms of lncRNAs in the context of EC and discuss their potential clinical applications as diagnostic and prognostic biomarkers.