Possible physiological role of H19 RNA

Role of long non-coding RNAs (lncRNAs) in gastric cancer metastasis: A comprehensive review

One of the greatest frequent types of malignancy is gastric cancer (GC). Metastasis, an essential feature of stomach cancer, results in a high rate of mortality and a poor prognosis. However, metastasis biological procedures are not well recognized. Long non-coding RNAs (lncRNAs) have a role in numerous gene regulation pathways via epigenetic modification as well as transcriptional and post-transcriptional control. LncRNAs have a role in a variety of disorders, such as cardiovascular disease, Alzheimer's, and cancer. LncRNAs are substantially related to GC incidence, progression, metastasis and drug resistance. Several research released information on the molecular processes of lncRNAs in GC pathogenesis. By interacting with a gene's promoter or enhancer region to influence gene expression, lncRNAs can operate as an oncogene or a tumor suppressor. This review includes the lncRNAs associated with metastasis of GC, which may give insights into the processes as well as potential clues for GC predicting and tracking.

Influence of H19 polymorphisms on breast cancer: risk assessment and prognostic implications via LincRNA H19/miR-675 and downstream pathways

Introduction

Breast cancer, as the most prevalent malignancy among women globally, continues to exhibit rising incidence rates, particularly in China. The disease predominantly affects women aged 40 to 60 and is influenced by both genetic and environmental factors. This study focuses on the role of H19 gene polymorphisms, investigating their impact on breast cancer susceptibility, clinical outcomes, and response to treatment.

Methods

We engaged 581 breast cancer patients and 558 healthy controls, using TaqMan assays and DNA sequencing to determine genotypes at specific loci (rs11042167, rs2071095, rs2251375). We employed in situ hybridization and immunohistochemistry to measure the expression levels of LincRNA H19, miR-675, MRP3, HOXA1, and MMP16 in formalin-fixed, paraffin-embedded samples. Statistical analyses included chi-squared tests, logistic regression, and Kaplan-Meier survival curves to evaluate associations between genetic variations, gene expression, and clinical outcomes.

Results

Genotypes AG at rs11042167, GT at rs2071095, and AC at rs2251375 were significantly associated with increased risk of breast cancer. Notably, the AA genotype at rs11042167 and TT genotype at rs2071095 were linked to favorable prognosis. High expression levels of LincRNA H19, miR-675, MRP3, HOXA1, and MMP16 in cancer tissues correlated with advanced disease stages and poorer survival rates. Spearman correlation analysis revealed significant positive correlations between the expression of LincRNA H19 and miR-675 and specific genotypes, highlighting their potential regulatory roles in tumor progression.

Discussion

The study underscores the critical roles of LincRNA H19 and miR-675 as prognostic biomarkers in breast cancer, with their overexpression associated with disease progression and adverse outcomes. The H19/LincRNA H19/miR-675/MRP3-HOXA1-MMP16 axis offers promising targets for new therapeutic strategies, reflecting the complex interplay between genetic markers and breast cancer pathology.

Conclusion

The findings confirm that certain H19 SNPs are associated with heightened breast cancer risk and that the expression profiles of related genetic markers can significantly influence prognosis and treatment response. These biomarkers hold potential as targets for personalized therapy and early detection strategies in breast cancer, underscoring the importance of genetic research in understanding and managing this disease.

M1 macrophage-derived exosomes promote autoimmune liver injury by transferring long noncoding RNA H19 to hepatocytes

Exosomes mediate intercellular communication by transmitting active molecules. The function of long noncoding RNA (lncRNA) H19 in autoimmune liver injury is unclear. Concanavalin A (ConA)-induced liver injury is well-characterized immune-mediated hepatitis. Here, we showed that lncRNA H19 expression was increased in the liver after ConA treatment, accompanied by increased exosome secretion. Moreover, injection of AAV-H19 aggravated ConA-induced hepatitis, with an increase in hepatocyte apoptosis. However, GW4869, an exosome inhibitor, alleviated ConA-induced liver injury and inhibited the upregulation of lncRNA H19. Intriguingly, lncRNA H19 expression in the liver was significantly downregulated, after macrophage depletion. Importantly, the lncRNA H19 was primarily expressed in type I macrophage (M1) and encapsulated in M1-derived exosomes. Furthermore, H19 was transported from M1 to hepatocytes via exosomes, and exosomal H19 dramatically induced hepatocytes apoptosis both in vitro and vivo. Mechanistically, H19 upregulated the transcription of hypoxia-inducible factor-1 alpha (HIF-1α), which accumulated in the cytoplasm and mediated hepatocyte apoptosis by upregulating p53. M1-derived exosomal lncRNA H19 plays a pivotal role in ConA-induced hepatitis through the HIF-1α-p53 signaling pathway. These findings identify M1 macrophage-derived exosomal H19 as a novel target for the treatment of autoimmune liver diseases.

lncRNA-mediated synovitis in rheumatoid arthritis: A perspective for biomarker development

Long noncoding RNAs (lncRNAs) are a regulatory class of noncoding RNAs with a wide range of activities such as transcriptional and post-transcriptional regulations. Emerging evidence has demonstrated that various lncRNAs contribute to the initiation and progression of Rheumatoid Arthritis (RA) through distinctive mechanisms. The present study reviews the recent findings on lncRNA role in RA development. It focuses on the involvement of different lncRNAs in the main steps of RA pathogenesis including T cell activation, cytokine dysregulation, fibroblast-like synoviocyte (FLS) activation and joint destruction. Besides, it discusses the current findings on RA diagnosis and the potential of lncRNAs as diagnostic, prognostic and predictive biomarkers in Rheumatology clinic.

Efficacy of DMARDs and methylprednisolone treatment on the gene expression levels of HSPA5, MMD, and non-coding RNAs MALAT1, H19, miR-199a-5p, and miR-1-3p, in patients with rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is a systemic autoimmune disease with chronic inflammation characterized by joint damage and even extra-articular involvement. In this study, the gene expression levels of MALAT1, H19 and their possible downstream microRNAs, miR-199a-5p, miR-1-3p, and the predicted targets of these miRNAs, HSPA5 and MMD, were examined.

METHODS

Twenty-five newly diagnosed RA patients and 25 healthy individuals were included. For six months, patients were treated with conventional disease-modifying antirheumatic drugs (DMARDs) and Methylprednisolone (mPRED). Blood samples were obtained from healthy controls and patients (before and after treatment). After RNA extraction, the RT-qPCR technique was used to evaluate the expression level of the studied genes.

RESULTS

Data showed that the expression level of MALAT1, H19, miR-199a-5p, and miR-1-3p was significantly higher in the newly diagnosed patients with RA than the healthy subjects, but the increase in the expression level of HSPA5 and MMD genes in the new cases was not significant compared to healthy controls. After treatment, except for the expression level of lncRNAs, the expression level of miRNAs, HSPA5, and MMD significantly increased. Based on ROC curve analysis of MALAT1, H19, miR-199a-5p and miR-1-3p have a high ability to identify patients from healthy individuals (AUC = 0.986, AUC = 0.995, AUC = 0.855, AUC = 0.675, respectively).

CONCLUSION

MALAT1 and H19 may be candidates as potential biomarkers for the discrimination between RA patients and controls. DMARDs plus mPRED therapy do not have a desirable effect on reducing inflammatory responses and ER stress.

The role and mechanism of long non-coding RNA H19 in stem cell osteogenic differentiation

Background

In recent years, H19, as one of the most well-known long non-coding RNA, has been reported to play important roles in many biological and physiological processes. H19 has been identified to regulate the osteogenic differentiation of various stem cells in many studies. However, the detailed role and regulation mechanism of H19 was not consistent in the reported studies.

Main body of the manuscript

In this review article we summarized the effect and mechanism of lncRNA H19 on osteogenic differentiation of various stem cells reported in the published literatures. The role and mechanism of H19, H19 expression changes, effect of H19 on cell proliferation in osteogenic differentiation were respectively reviewed.

Conclusions

An increasing number of studies have provided evidence that H19 play its role in the regulation of stem cell osteogenic differentiation by different mechanisms. Most of the studies favored the positive regulatory effect of H19 through lncRNA-miRNA pathway. The function and underlying mechanisms by which H19 contributes to osteogenic differentiation require further investigation.

LncRNA MORT (ZNF667-AS1) in Cancer-Is There a Possible Role in Gynecological Malignancies?

Gynecological cancers (GCs) are currently among the major threats to female health. Moreover, there are different histologic subtypes of these cancers, which are defined as ‘rare’ due to an annual incidence of <6 per 100,000 women. The majority of these tend to be associated with a poor prognosis. Long non-coding RNAs (lncRNAs) play a critical role in the normal development of organisms as well as in tumorigenesis. LncRNAs can be classified into tumor suppressor genes or oncogenes, depending on their function within the cellular context and the signaling pathways in which they are involved. These regulatory RNAs are potential therapeutic targets for cancer due to their tissue and tumor specificity. However, there still needs to be a deeper understanding of the mechanisms by which lncRNAs are involved in the regulation of numerous biological functions in humans, both in normal health and disease. The lncRNA Mortal Obligate RNA Transcript (MORT; alias ZNF667-AS1) has been identified as a tumor-related lncRNA. ZNF667-AS1 gene, located in the human chromosome region 19q13.43, has been shown to be silenced by DNA hypermethylation in several cancers. In this review, we report on the biological functions of ZNF667-AS1 from recent studies and describe the regulatory functions of ZNF667-AS1 in human disease, including cancer. Furthermore, we discuss the emerging insights into the potential role of ZNF667-AS1 as a biomarker and novel therapeutic target in cancer, including GCs (ovarian, cervical, and endometrial cancers).

H19/miR-107/HMGB1 axis sensitizes laryngeal squamous cell carcinoma to cisplatin by suppressing autophagy in vitro and in vivo

Laryngeal squamous cell carcinoma (LSCC) is the most common malignant tumor, which occurs in the head and neck. Current treatments for LSCC are all largely weakened by increasing drug resistance. Our study aimed to investigate the effects of long noncoding RNA (lncRNA) H19 on drug resistance in LSCC. In our study, we found that the level of H19 was sharply upregulated in LSCC tissues and drug-resistant cells compared with the control. Besides, the expression of high-mobility group B1 (HMGB1) was elevated, and microRNA107 (miR-107) was suppressed in drug-resistant cells compared with the control. Further study revealed that the interference of H19 by short hairpin RNA (shRNA) effectively suppressed high autophagy level and obvious drug resistance in drug-resistant cells. Besides that, miR-107 was predicted as a target of H19 and inhibiting effects of H19 shRNA on autophagy and drug resistance were both reversed by miR-107 inhibitor. Moreover, HMGB1 was predicted as a target of miR-107 in LSCC cells and knockdown of HMGB1 was able to suppress autophagy and drug resistance in LSCC cells. In addition, our investigation demonstrated that H19 shRNA exerted an inhibiting effect on autophagy and drug resistance by downregulating HMGB1 by targeting miR-107. Finally, the in vivo experiment revealed that LV-H19 shRNA strongly suppressed drug resistance compared with the usage of cisplatin individually. Taken together, our research indicated an H19-miR-107-HMGB1 axis in regulating the autophagy-induced drug resistance in LSCC in vitro and in vivo, providing novel targets for molecular-targeted therapy and broadening the research for LSCC.

Association between lncRNA-H19 polymorphisms and hepatoblastoma risk in an ethic Chinese population

H19 polymorphisms are associated with increased susceptibility to several cancers; however, their role in hepatoblastoma remains unclear. In this study, we investigated the association between three H19 polymorphisms (rs2839698 G>A, rs3024270 C>G, rs217727 G>A) and hepatoblastoma susceptibility in 213 hepatoblastoma patients. The rs2839698 and rs3024270 polymorphisms were associated with significantly increased hepatoblastoma risk, with the GG genotype associated with a higher risk of hepatoblastoma than the CC genotype at the rs3024270 locus. The rs217727 polymorphism was associated with significantly decreased hepatoblastoma risk, with the AG genotype associated with a lower risk of hepatoblastoma than the GG genotype. These findings were confirmed by combined analysis, and stratification analysis revealed that age, gender and clinical stage were associated with increased hepatoblastoma susceptibility. The GGG and AGG haplotypes were significantly associated with increased hepatoblastoma risk compared with the GCA reference (rs2839698, rs3024270, rs217727). The rs2839698 and rs3024270 polymorphisms correlated with decreased MRPL23-AS1 expression, whereas the rs217727 polymorphism was associated with increased MRPL23-AS1 expression. Overall, the H19 rs2839698, rs3024270 and rs217727 polymorphisms were associated with hepatoblastoma susceptibility in a Chinese Han population.

Long non-coding RNA (lncRNA) PGM5P4-AS1 inhibits lung cancer progression by up-regulating leucine zipper tumor suppressor (LZTS3) through sponging microRNA miR-1275

It is necessary to explore new molecules for the improvement of precise diagnosis and antitumor therapies in lung cancer. LncRNAs (long non-coding RNAs) play an important role in the regulation of cancer cell malignant behavior and tumor development. In this work, we found that a newly discovered lncRNA, lncRNA PGM5P4-AS1, was lower expressed in lung cancer tissues than adjacent tissues. Then, the lncRNA PGM5P4-AS1 was overexpressed or knocked-down in different lung cancer cells, and its effects on the malignant phenotypes were measured by 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, cell cycle assay, wound healing assay, and transwell assay. The results showed that the overexpression of PGM5P4-AS1 inhibited lung cancer cell proliferation, migration, and invasion activities, while these abilities were prominently promoted by the interference of PGM5P4-AS1. Further, the growth of lung cancer tumors in nude mice was also inhibited by PGM5P4-AS1 overexpression. In mechanism, PGM5P4-AS1 has the binding site of miR-1275 and could positively regulate the expression of LZTS3 via sponging miR-1275. In conclusion, PGM5P4-AS1 could be a potential precise diagnosis and therapeutic target biomarker of lung cancer.

The Roles of H19 in Regulating Inflammation and Aging

Accumulating evidence suggests that long non-coding RNA H19 correlates with several aging processes. However, the role of H19 in aging remains unclear. Many studies have elucidated a close connection between H19 and inflammatory genes. Chronic systemic inflammation is an established factor associated with various diseases during aging. Thus, H19 might participate in the development of age-related diseases by interplay with inflammation and therefore provide a protective function against age-related diseases. We investigated the inflammatory gene network of H19 to understand its regulatory mechanisms. H19 usually controls gene expression by acting as a microRNA sponge, or through mir-675, or by leading various protein complexes to genes at the chromosome level. The regulatory gene network has been intensively studied, whereas the biogenesis of H19 remains largely unknown. This literature review found that the epithelial-mesenchymal transition (EMT) and an imprinting gene network (IGN) might link H19 with inflammation. Evidence indicates that EMT and IGN are also tightly controlled by environmental stress. We propose that H19 is a stress-induced long non-coding RNA. Because environmental stress is a recognized age-related factor, inflammation and H19 might serve as a therapeutic axis to fight against age-related diseases.

Emerging Roles of Long non-coding RNAs in The Tumor Microenvironment

Long non-coding RNAs (lncRNAs) are a diverse class of longer than 200 nucleotides RNA transcripts that have limited protein coding capacity. LncRNAs display diverse cellular functions and widely participate in both physiological and pathophysiological processes. Aberrant expressions of lncRNAs are correlated with tumor progression, providing sound rationale for their targeting as attractive anti-tumor therapeutic strategies. Emerging evidences support that lncRNAs participate in tumor-stroma crosstalk and stimulate a distinctive and suitable tumor microenvironment (TME). The TME comprises several stromal cells such as cancer stem cells (CSCs), cancer-associated endothelial cells (CAEs), cancer-associated fibroblasts (CAFs) and infiltrated immune cells, all of which are involved in the complicated crosstalk with tumor cells to affect tumor progression. In this review, we summarize the essential properties and functional roles of known lncRNAs in related to the TME to validate lncRNAs as potential biomarkers and promising anti-cancer targets.

Involvement of long noncoding RNAs in the pathogenesis of autoimmune diseases

Autoimmune diseases are a group of heterogeneous disorders characterized by damage to various organs caused by abnormal innate and adaptive immune responses. The pathogenesis of autoimmune diseases is extremely complicated and has not yet been fully elucidated. Long noncoding RNAs (lncRNAs), which are defined as transcripts containing more than 200 nucleotides with no protein-coding capacity, are emerging as important regulators of gene expression via epigenetic modification, transcriptional regulation and posttranscriptional regulation. Accumulating evidence has demonstrated that lncRNAs play a key role in the regulation of immunological functions and autoimmunity. In this review, we discuss various molecular mechanisms by which lncRNAs regulate gene expression and recent findings regarding the involvement of lncRNAs in many human autoimmune diseases, including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), idiopathic inflammatory myopathy (IIM), systemic sclerosis (SSc) and Sjögren’s syndrome (pSS).

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lncRNAs are observed to be differentially expressed in various autoimmune diseases.

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lncRNAs are involved in abnormal immune regulation and inflammatory responses in autoimmune diseases, which provides new insight into disease pathogenesis.

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LncRNAs may have the potential of biomarkers for diagnosis and prognosis of autoimmune diseases.

Long non-coding RNA H19 regulates endothelial cell aging via inhibition of STAT3 signalling

Aims

Long non-coding RNAs (lncRNAs) have been shown to regulate numerous processes in the human genome, but the function of these transcripts in vascular aging is largely unknown. We aim to characterize the expression of lncRNAs in endothelial aging and analyse the function of the highly conserved lncRNA H19.

Methods and results

H19 was downregulated in endothelium of aged mice. In human, atherosclerotic plaques H19 was mainly expressed by endothelial cells and H19 was significantly reduced in comparison to healthy carotid artery biopsies. Loss of H19 led to an upregulation of p16 and p21, reduced proliferation and increased senescence in vitro. Depletion of H19 in aortic rings of young mice inhibited sprouting capacity. We generated endothelial-specific inducible H19 deficient mice (H19iEC-KO), resulting in increased systolic blood pressure compared with control littermates (Ctrl). These H19iEC-KO and Ctrl mice were subjected to hindlimb ischaemia, which showed reduced capillary density in H19iEC-KO mice. Mechanistically, exon array analysis revealed an involvement of H19 in IL-6 signalling. Accordingly, intercellular adhesion molecule 1 and vascular cell adhesion molecule 1 were upregulated upon H19 depletion. A luciferase reporter screen for differential transcription factor activity revealed STAT3 as being induced upon H19 depletion and repressed after H19 overexpression. Furthermore, depletion of H19 increased the phosphorylation of STAT3 at TYR705 and pharmacological inhibition of STAT3 activation abolished the effects of H19 silencing on p21 and vascular cell adhesion molecule 1 expression as well as proliferation.

Conclusion

These data reveal a pivotal role for the lncRNA H19 in controlling endothelial cell aging.

The prognostic value of long non-coding RNA H19 in various cancers: A meta-analysis based on 15 studies with 1584 patients and the Cancer Genome Atlas data

BACKGROUND

Recent studies have shown that long noncoding RNA (lncRNA) H19 is aberrantly expressed in various cancers. However, the prognostic significance of H19 in cancer patients remains to be elucidated. Here, we designed and conducted a meta-analysis to evaluate the prognostic value of this lncRNA for malignant solid neoplasms.

METHODS

Relevant publications were collected from PubMed, Cochrane Library, Web of Science, and Embase databases. The relevant survival data of patients with H19-associated cancers were downloaded from The Cancer Genome Atlas (TCGA) project. Statistically significant relationships between H19 expression levels and overall survival were analyzed by hazard ratios (HRs) and corresponding 95% confidence intervals (CIs).

RESULTS

A total of 15 studies with 1584 patients were ultimately included for this literature meta-analysis. An elevated level of H19 expression was found to be negatively correlated with the overall survival (OS) (HR = 1.62, 95% CI = 1.36-1.93, P < .001) in various cancers. Abnormal H19 expression was also positively correlated with poor tumor differentiation (P < .0001), more advanced clinical stage (P < .0001), earlier lymph node metastasis (P < .0001), and earlier distant metastasis (P < .05). The relationship between elevated H19 expression and overall survival was further validated by a TCGA dataset consisting of 7462 cancer patients (HR = 1.12, 95% CI = 1.03-1.22, P < .05).

CONCLUSION

Our study indicates that H19 expression is closely relevant to clinical outcome and suggests that lncRNA H19 could be a crucial prognostic biomarker for certain carcinoma types.

LncRNA H19 initiates microglial pyroptosis and neuronal death in retinal ischemia/reperfusion injury

Ischemia-reperfusion (I/R) is a common pathology when the blood supply to an organ was disrupted and then restored. During the reperfusion process, inflammation and tissue injury were triggered, which were mediated by immunocytes and cytokines. However, the mechanisms initiating I/R-induced inflammation and driving immunocytes activation remained largely unknown. In this study, we identified long non-coding RNA (lncRNA)-H19 as the key onset of I/R-induced inflammation. We found that I/R increased lncRNA-H19 expression to significantly promote NLRP3/6 inflammasome imbalance and resulted in microglial pyroptosis, cytokines overproduction, and neuronal death. These damages were effectively inhibited by lncRNA-H19 knockout. Specifically, lncRNA-H19 functioned via sponging miR-21 to facilitate PDCD4 expression and formed a competing endogenous RNA network (ceRNET) in ischemic cascade. LncRNA H19/miR-21/PDCD4 ceRNET can directly regulate I/R-induced sterile inflammation and neuronal lesion in vivo. We thus propose that lncRNA-H19 is a previously unknown danger signals in the molecular and immunological pathways of I/R injury, and pharmacological approaches to inhibit H19 seem likely to become treatment modalities for patients in the near future based on these mechanistic findings.

H19 lncRNA: Roles in tumorigenesis

H19 is a long non-coding RNA [lncRNA] which was firstly described as an oncofetal transcript. The imprinted gene is normally expressed from the maternal allele. However, this pattern of imprinting is dysregulated in several cancers leading to aberrant up-regulation of H19 in malignant tissues. Several studies have utilized this aberrant expression pattern to find specific biomarkers for detection of cancer in tumoral tissues or peripheral blood. Moreover, single nucleotide polymorphisms within H19 have been associated with risk of oral squamous cell carcinoma, hepatocellular carcinoma, breast cancer, bladder cancer, gastric cancer and colorectal cancer. Taken together, H19 is regarded as a biomarker for cancer and a putative therapeutic target in these human disorders.

High level of lncRNA H19 expression is associated with shorter survival in esophageal squamous cell cancer patients

AIM

Long non-coding RNA (lncRNA) is currently considered to play an important regulatory role in various diseases, including tumors, at present a hot topic in research. As a non-coding transcription product of imprinted gene, LncRNA H19 is expressed as a parent imprinted maternal allele without protein-coding ability. Increasing evidence indicates that LncH19 may be a new tumor marker for early clinical diagnosis and prognosis judgment. In this study, LncH19 expression was investigated by RNA in situ hybridization for further exploring the clinicopathological role of its expression in esophageal squamous cell cancer (ESCC).

METHODS

121 tumor samples and seven cases of adjacent non-tumor tissues from esophageal cancer patients were detected by RNA in situ hybridization (ISH) and the ISH staining was graded with modified Allred scoring.

RESULTS

While no LncH19 expression in the tumor adjacent to normal epithelia was disclosed with the technology, significantly higher levels of LncH19 expression were detected in the tumors obtained from the patients who died within one year after surgery, compared to the expression in those tumors from the patients who survived longer than five years after the same treatment regimen (P = 0.001). In addition, LncH19 expression was verified to correlate with a larger tumor size (P = 0.002) and a higher UICC stage (P = 0.001).

CONCLUSION

Our LncH19 ISH data verify the involvement of LncH19 in ESCC. Higher levels of LncH19 expression were not only detected in tumors with larger size and in clinical late stage, but also significantly associated with shorter survival, strongly indicating its clinical significance in the malignant progression of ESCC and useful value as a poor prognostic factor for the patients.

H19-Dependent Transcriptional Regulation of β3 and β4 Integrins Upon Estrogen and Hypoxia Favors Metastatic Potential in Prostate Cancer

Estrogen and hypoxia promote an aggressive phenotype in prostate cancer (PCa), driving transcription of progression-associated genes. Here, we molecularly dissect the contribution of long non-coding RNA H19 to PCa metastatic potential under combined stimuli, a topic largely uncovered. The effects of estrogen and hypoxia on H19 and cell adhesion molecules’ expression were investigated in PCa cells and PCa-derived organotypic slice cultures (OSCs) by qPCR and Western blot. The molecular mechanism was addressed by chromatin immunoprecipitations, overexpression, and silencing assays. PCa cells’ metastatic potential was analyzed by in vitro cell-cell adhesion, motility test, and trans-well invasion assay. We found that combined treatment caused a significant H19 down-regulation as compared with hypoxia. In turn, H19 acts as a transcriptional repressor of cell adhesion molecules, as revealed by up-regulation of both β3 and β4 integrins and E-cadherin upon H19 silencing or combined treatment. Importantly, H19 down-regulation and β integrins induction were also observed in treated OSCs. Combined treatment increased both cell motility and invasion of PCa cells. Lastly, reduction of β integrins and invasion was achieved through epigenetic modulation of H19-dependent transcription. Our study revealed that estrogen and hypoxia transcriptionally regulate, via H19, cell adhesion molecules redirecting metastatic dissemination from EMT to a β integrin-mediated invasion.

Current advances in BCG-unresponsive non-muscle invasive bladder cancer

Introduction: The current first line therapy for high grade (HG) non-muscle invasive bladder cancer (NMIBC) is intravesical Bacillus Calmette-Guerin (BCG). Patients who recur or progress despite BCG are recommended to undergo radical cystectomy or participate in clinical trials. There is an urgent need for alternative therapies in the BCG-unresponsive NMIBC realm. Areas covered: We queried clinicaltrials.gov and pubmed.gov for current and recently completed early clinical trials pertaining to investigational agents used for the treatment of BCG-unresponsive NMIBC. These included intravesical chemotherapy, immunotherapy, vaccines, gene therapy, viruses, and agents used with novel drug delivery methods. In this article, we discuss the treatment guidelines for non-muscle invasive bladder cancer and therapeutic approaches under investigation in clinical trials. Expert opinion: The FDA is currently allowing single-arm studies as a pathway for approval in BCG-refractory patients with CIS. Although many agents are currently undergoing testing, none have been approved since Valrubicin. Hopefully, we will identify therapies sufficiently effective and durable to achieve FDA approval. Other considerations in this realm include the use of biomarkers in NMIBC to identify patients who will most likely respond to specific interventions. In addition, as systemic agents such as checkpoint inhibitors, are studied further, a multidisciplinary approach may be needed to treat this subset of patients.

Associations between H19 polymorphisms and neuroblastoma risk in Chinese children

BackgroundH19 polymorphisms have been reported to correlate with an increased susceptibility to a few types of cancers, although their role in neuroblastoma has not yet been clarified.Materials and methods We investigated the association between three single polymorphisms (rs2839698 G>A, rs3024270 C>G, and rs217727 G>A) and neuroblastoma susceptibility in Chinese Han populations. Three hundred ninety-three neuroblastoma patients and 812 healthy controls were enrolled from the Henan and Guangdong provinces. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to determine the strength of the association of interest.Results Separated and combined analyses revealed no associations of the rs2839698 G>A, rs3024270 C>G or rs217727 G>A polymorphisms and neuroblastoma susceptibility. In the stratification analysis, female children with rs3024270 GG genotypes had an increased neuroblastoma risk (adjusted OR = 1.61, 95% CI = 1.04-2.50, P=0.032).Conclusion The rs3024270 GG genotype might contribute to an increased neuroblastoma susceptibility in female Chinese children.

Long non-coding RNAs in metastasis

Long non-coding RNA (lncRNA) genes have recently been discovered as key regulators of developmental, physiological, and pathological processes in humans. Recent studies indicate that lncRNAs regulate every step of gene expression, and their aberrant expression can be found in the majority of cancer types. Particularly, lncRNAs were found to function in tumor development and metastasis, which is the major cause of cancer-related death. Thus, exploring key roles of lncRNAs in metastasis is predicted to enhance our knowledge of metastasis, and uncover novel therapeutic targets and biomarkers of this process. In this review, we discuss the molecular mechanisms of lncRNAs in gene expression regulation and their function in metastasis.

LncRNA H19 promotes the proliferation of pulmonary artery smooth muscle cells through AT1R via sponging let-7b in monocrotaline-induced pulmonary arterial hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is related to inflammation, and the lncRNA H19 is associated with inflammation. However, whether PDGF-BB-H19-let-7b-AT1R axis contributes to the pathogenesis of PAH has not been thoroughly elucidated to date. This study investigated the role of H19 in PAH and its related mechanism.

METHODS

In the present study, SD rats, C57/BL6 mice and H19-/- mice were injected with monocrotaline (MCT) to establish a PAH model. H19 was detected in the cytokine-stimulated pulmonary arterial smooth muscle cells (PASMCs), serum and lungs of rats/mice. H19 overexpression and knockdown experiments were also conducted. A dual luciferase reporter assay was used to explore whether let-7b is a sponge miRNA of H19, and AT1R is a novel target of let-7b. A CCK-8 assay and flow cytometry were used to analyse cell proliferation.

RESULTS

The results showed that H19 was highly expressed in the serum and lungs of MCT-induced rats/mice, and H19 was upregulated by PDGF-BB in vitro. H19 upregulated AT1R expression via sponging miRNA let-7b following PDGF-BB stimulation. AT1R is a novel target of let-7b. Moreover, the overexpression of H19 and AT1R could facilitate PASMCs proliferation in vitro. H19 knockout protected mice from pulmonary artery remodeling and PAH following MCT treatment.

CONCLUSION

Our study showed that H19 is highly expressed in MCT-induced rodent lungs and upregulated by PDGF-BB. The H19-let-7b-AT1R axis contributed to the pathogenesis of PAH by stimulating PASMCs proliferation. The H19 knockout had a protective role in the development of PAH. H19 may be a potential tar-get for the treatment of PAH.

Multidimensional communication of microRNAs and long non-coding RNAs in lung cancer

PURPOSE

Non-coding RNAs (ncRNAs) have been a hot topic for many years in the field of cancer research, especially miRNAs and lncRNAs. Because they play critical roles in regulating various cellular processes and are more often involved in tumorigenesis than protein-coding genes. But the cross talk between miRNAs and lncRNAs in cancer has been scarcely studied. This article aims to provide a retrospective review of the latest research on the link between miRNAs and lncRNAs in lung cancer and discusses their potential role as diagnostic biomarkers and therapeutic targets for lung cancer in clinical practice.

METHODS

We reviewed literatures about ncRNAs and lung cancer from PUBMED databases in this article.

RESULTS

As shown in our review, miRNAs and lncRNAs could represent underlying targets for diagnosis, therapy, prognosis, and drug resistence of lung cancer. By acting as ceRNAs, lncRNAs can competitively inhibit the expression levels of miRNAs, and the lncRNA/miRNA axis can contribute to tumorigenesis, metastasis, and mutidrug resistance in lung cancer via various classic signaling pathways or related proteins.

CONCLUSION

Based on present knowledge, ncRNAs may provide a novel perspective to understand the pathogenesis of lung cancer and could be candidates in screening of therapeutic targets for lung cancer.

Long Noncoding RNAs and Cardiac Disease

SIGNIFICANCE

To maintain homeostasis, gene expression has to be tightly regulated by complex and multiple mechanisms occurring at the epigenetic, transcriptional, and post-transcriptional levels. One crucial regulatory component is represented by long noncoding RNAs (lncRNAs), nonprotein-coding RNA species implicated in all of these levels. Thus, lncRNAs have been associated with any given process or pathway of interest in a variety of systems, including the heart. Recent Advances: Mounting evidence implicates lncRNAs in cardiovascular diseases (CVD) and progression and their presence in the blood of heart disease patients indicates that they are attractive potential biomarkers.

CRITICAL ISSUES

Our understanding of the regulation and molecular mechanisms of action of most lncRNAs remains rudimentary. A challenge is represented by their often low evolutionary sequence conservation that limits the use of animal models for preclinical studies. Nevertheless, a growing number of lncRNAs with an impact on heart function is rapidly accumulating. In this study, we will discuss (i) lncRNAs that control heart homeostasis and disease; (ii) concepts, approaches, and methodologies necessary to study lncRNAs in the heart; and (iii) challenges posed and opportunities presented by lncRNAs as potential therapeutic targets and biomarkers.

FUTURE DIRECTIONS

A deeper knowledge of the molecular mechanisms underpinning CVDs is necessary to develop more effective treatments. Further studies are needed to clarify the regulation and function of lncRNAs in the heart before they can be considered as therapeutic targets and disease biomarkers. Antioxid. Redox Signal. 29, 880-901.

Association between H19 SNP rs217727 and lung cancer risk in a Chinese population: a case control study

Background

H19 was the first long non-coding RNA (lncRNA) to be confirmed. Recently, studies have suggested that H19 may participate in lung cancer (LC) development and progression. This study assessed whether single nucleotide polymorphisms (SNPs) in H19 are associated with the risk of LC in a Chinese population.

Methods

A case-control study was performed, and H19 SNP rs217727 was analyzed in 555 lung cancer patients from two hospitals and 618 healthy controls to test the association between this SNP and the susceptibility to LC.

Results

The A/A homozygous genotype of rs217727 was significantly associated with an increased LC risk (odds ratio (OR) = 1.661, 95% confidence interval (CI) = 1.155 to 2.388, P = 0.006). Significant associations remained after stratification by smoking status (P < 0.001). Furthermore, the A/A genotype had a higher risk of LC than those of G/G in the squamous cell carcinoma (OR = 2.022, P = 0.004) and adenocarcinoma (OR = 1.606, P = 0.045) subgroups.

Conclusions

The rs217727 SNP in lncRNA H19 was significantly associated with susceptibility to LC, particularly in squamous cell carcinoma and adenocarcinoma, and identified the homozygous A/A genotype as a risk factor for LC.

The role of long non-coding RNAs in rheumatic diseases

Long non-coding RNAs (lncRNAs) have emerged as key epigenetic regulators that govern gene expression and influence multiple biological processes. Accumulating evidence demonstrates that lncRNAs have critical roles in immune cell development and function. In this Review, the molecular mechanisms of gene expression regulation by lncRNAs are described and current knowledge of the role of lncRNAs in immune regulation and inflammation are presented, highlighting strategies for defining the roles of lncRNAs in the pathogenesis of multiple rheumatic diseases. Finally, research progress in understanding the role of lncRNAs in rheumatic diseases is discussed.

Epigenome Aberrations: Emerging Driving Factors of the Clear Cell Renal Cell Carcinoma

Clear cell renal cell carcinoma (ccRCC), the most common form of Kidney cancer, is characterized by frequent mutations of the von Hippel-Lindau (VHL) tumor suppressor gene in ~85% of sporadic cases. Loss of pVHL function affects multiple cellular processes, among which the activation of hypoxia inducible factor (HIF) pathway is the best-known function. Constitutive activation of HIF signaling in turn activates hundreds of genes involved in numerous oncogenic pathways, which contribute to the development or progression of ccRCC. Although VHL mutations are considered as drivers of ccRCC, they are not sufficient to cause the disease. Recent genome-wide sequencing studies of ccRCC have revealed that mutations of genes coding for epigenome modifiers and chromatin remodelers, including PBRM1, SETD2 and BAP1, are the most common somatic genetic abnormalities after VHL mutations in these tumors. Moreover, recent research has shed light on the extent of abnormal epigenome alterations in ccRCC tumors, including aberrant DNA methylation patterns, abnormal histone modifications and deregulated expression of non-coding RNAs. In this review, we discuss the epigenetic modifiers that are commonly mutated in ccRCC, and our growing knowledge of the cellular processes that are impacted by them. Furthermore, we explore new avenues for developing therapeutic approaches based on our knowledge of epigenome aberrations of ccRCC.

Dysregulated expression of long noncoding RNAs in gynecologic cancers

Cancers of the female reproductive system include ovarian, uterine, vaginal, cervical and vulvar cancers, which are termed gynecologic cancer. The emergence of long noncoding RNAs (lncRNAs), which are believed to play a crucial role in several different biological processes, has made the regulation of gene expression more complex. Although the function of lncRNAs is still rather elusive, their broad involvement in the initiation and progression of various cancers is clear. They are also involved in the pathogenesis of cancers of the female reproductive system. LncRNAs play a critical physiological role in apoptosis, metastasis, invasion, migration and cell proliferation in these cancers. Different expression profiles of lncRNAs have been observed in various types of tumors compared with normal tissues and between malignant and benign tumors. These differential expression patterns may lead to the promotion or suppression of cancer development and tumorigenesis. In the current review, we present the lncRNAs that show a differential expression between cancerous and normal tissues in ovarian, cervical and endometrial cancers, and highlight the associations between lncRNAs and some of the molecular pathways involved in these cancers.

Expression profiling of long non-coding RNA identifies linc-RoR as a prognostic biomarker in oral cancer

Oral squamous cell carcinoma is the most aggressive cancer that is associated with high recurrence, metastasis, and poor treatment outcome. Dysregulation of long non-coding RNAs has been shown to promote tumor growth and metastasis in several cancers. In this study, we investigated the expression of 11 selected long non-coding RNAs that are associated with cell proliferation, metastasis, and tumor suppression in oral squamous cell carcinomas and normal tissues by quantitative real-time polymerase chain reaction. Out of the 11 long non-coding RNAs profiled, 9 were significantly overexpressed in tumors with tobacco chewing history. Moreover, the long non-coding RNA profile was similar to the head and neck cancer datasets of The Cancer Genome Atlas database. Linc-RoR, a regulator of reprogramming, implicated in tumorigenesis was found to be overexpressed in undifferentiated tumors and showed strong association with tumor recurrence and poor therapeutic response. In oral squamous cell carcinomas, for the first time, we observed linc-RoR overexpression, downregulation of miR-145-5p, and overexpression of c-Myc, Klf4, Oct4, and Sox2, suggesting the existence of linc-RoR-mediated competing endogenous RNA network in undifferentiated tumors. Taken together, this study demonstrated the association of linc-RoR overexpression in undifferentiated oral tumors and its prognostic value to predict the therapeutic response.

Long noncoding RNAs: emerging regulators of tumor angiogenesis

Long noncoding RNAs (lncRNAs) participate in multiple biological processes especially human diseases, of which, tumor seems to be one of the most significant. Angiogenesis has been deemed to have a pivotal role in a series of tumor biological behaviors in tumorigenesis, progression and prognosis. Emerging evidences suggested that lncRNAs are involved in tumor angiogenesis and lncRNAs have already been verified to be potential biomarkers and promising therapeutic targets. This review summarized emerging angiogenesis-related lncRNAs, discussed their mechanisms interacting with cytokines, cancer stem cells, miRNAs and tumor hypoxia microenvironment, and demonstrated if lncRNAs could be new candidate targets of antiangiogenesis therapy.

Long Non-coding RNAs and their Role in Metastasis

The perception of long non-coding RNAs as chunk RNA and transcriptional noise has been steadily replaced by their role as validated targets for a diverse set of physiological processes in the past few years. However, for the vast majority of lncRNAs their precise mode of action and physiological function remain to be uncovered. A large body of evidence has revealed their essential role in all stages of cancirogenesis and metastasis. In this review we focus on the role of lncRNAs in metastasis. We grouped selected lncRNAs into three categories based on in vitro and in vivo mode of action-related studies and clinical relevance for metastasis. Grouped according to their mode of action, in category I we discuss lncRNAs such as CCAT2, DREH, LET, NKILA, treRNA, HOTAIR, H19, FENDRR, lincROR, MALAT, GClnc1, BCAR4, SCHLAP1 and lncRNA ATP, all lncRNAs with in vitro and in vivo metastasis-related data and clinical significance. In category II we discuss lncRNAs CCAT1, PCAT1, PTENgp1, GPLINC, MEG3, ZEB2-AS, LCT13, ANRIL, NBAT1 and lncTCF7 all characterized by their mode of action in vitro and clinical significance, but pending or preliminary in vivo data. Finally, under category III, we discuss lncRNAs BANCR, FRLnc1, SPRY4-IT1 and LIMT with partially or poorly-resolved mode of action and varying degree of validation in clinical metastasis. Finally we discuss metastasis-related translational aspects of lncRNAs.

H19 promotes the migration and invasion of colon cancer by sponging miR-138 to upregulate the expression of HMGA1

Colon cancer is the most common digestive system malignancy, along with high mortality rate, familial transmissibility and hepatic metastasis. Our study investigated the role of long non-coding RNA H19 in colon cancer. We found that H19 was overexpressed in colon cancer tissues and cell lines, the interference of H19 by short hairpin RNA (shRNA) effectively decreased the migration and invasion of colon cancer cells (HT-29 and RKO). Besides, miR-138 was predicted a target of H19, and low expression of miR-138 was found in colon cancer tissues and cells. The silence of H19 strongly increased the expression of miR-138. The decreased level of miR-138 was elevated adding miR-138 mimic in RKO cells transfected with lncRNA-H19. Similarly, the upregulated level of miR-138 was downregulated adding miR-138 inhibitor in RKO cells transfected with H19 shRNA. The luciferase reporter confirmed the targeting reaction between H19 and miR-138. Moreover, the high-mobility group A (HMGA1) protein was predicted as a target of miR-138. HMGA1 was suppressed by H19 shRNA and could be up-regulated by miR-138 inhibitor. The migration and invasion ability of colon cancer was restrained by H19 shRNA and promoted by miR-138 inhibitor. Finally, the in vivo experiment revealed that H19 shRNA strongly reduced the tumor growth and tumor volume. H19 shRNA also inhibited metastasis via suppressing hepatic metastases and the expression of metastasis-related proteins. Taken together, our research indicated an H19-miR138-HMGA1 pathway in regulating the migration and invasion of colon cancer, providing new insight for treatment of colon cancer.

H19 non-coding RNA in urine cells detects urothelial carcinoma: a pilot study

CONTEXT

Urothelial carcinoma (UC) is common and highly recurrent. Diagnosis and follow-up involve invasive cystoscopies.

OBJECTIVE

To evaluate H19 RNA in urine cells as diagnostic tool for UC.

MATERIALS AND METHODS

RT-PCR analysis of urine samples from healthy volunteers and UC patients.

RESULTS

H19 RNA was unequivocally detected in the urine of 90.5% of patients and 25.9% of controls. H19 copies were three orders of magnitude higher in patients. Receiver operating characteristic analysis showed an area under the curve of 0.933.

CONCLUSIONS

This pilot study shows that urinary cell H19 is a highly sensitive test for UC and pending verification could transform patient management.

A phase 1/2a, dose-escalation, safety, pharmacokinetic, and preliminary efficacy study of intraperitoneal administration of BC-819 (H19-DTA) in subjects with recurrent ovarian/peritoneal cancer

BACKGROUND

H19 is a paternally imprinted, oncofetal gene expressed in various embryonic tissues and in 85% of the ovarian tumors. H19-DTA (BC-819) is a DNA plasmid that drives the expression of the diphtheria toxin gene under the regulation of the H19 promoter sequence and therefore is a potential treatment for various tumors that overexpress the H19 gene, among them-ovarian cancer.

OBJECTIVE

To assess the safety and efficacy of intra-peritoneal (IP) instillations of H19-DTA (BC-819) plasmid in treating ovarian/peritoneal cancer patients with advanced recurrent disease.

METHODS

A phase 1-2A multi-centric trial included 14 eligible patients who were either platinum-refractory or platinum-resistant with positive H19 expression. Patients were treated IP with escalating weekly doses of BC-819 for a maximum of 6-9 weeks. Dose-limiting toxicities (DLT) were assessed after the first course of treatment for each patient and each subsequent cohort was enrolled once each subject had completed the first course of treatment and its 4-week follow-up period. The occurrence of adverse events (AEs) and response to treatment were assessed after the induction course and then periodically.

RESULTS

During the study, no DLTs were observed. Only 5 grade 1 and 2 AEs, which occurred in 4 patients were considered as possibly related to BC-819. The best tumor response seen was stable disease. Median survivals of 3.2, 5.3 and 6.5 months were observed for the 60, 120 and 240 mg cohorts, respectively.

CONCLUSIONS

BC-819 can be considered safe and well tolerated in intraperitoneal doses up to 240 mg. Hybridization of intraperitoneal chemotherapy with the biological treatment of BC-819 should be further evaluated in phase 2 and 3 studies.

Long non-coding RNAs in colorectal cancer

Colorectal cancer (CRC) is one of the leading causes of cancer-related death worldwide. Despite substantial progress in understanding the molecular mechanisms and treatment of CRC in recent years, the overall survival rate of CRC patients has not improved dramatically. The development of CRC is multifactor and multistep processes, in which abnormal gene expression may play an important role. With the advance of human tumor molecular biology, a series of studies have highlighted the role of long non-coding RNAs (lncRNAs) in the development of CRC. CRC-related lncRNAs have been demonstrated to regulate the genes by various mechanisms, including epigenetic modifications, lncRNA-miRNA and lncRNA-protein interactions, and by their actions as miRNA precursors or pseudogenes. Since some lncRNAs can be detected in human body fluid and have good specificity and accessibility, they have been suggested to be used as novel potential biomarkers for CRC diagnosis and prognosis as well as in the prediction of the response to therapy. Therefore, in this review, we will focus on lncRNAs in CRC development, the mechanisms and biomarkers of lncRNAs in CRC.

H19 promotes endometrial cancer progression by modulating epithelial-mesenchymal transition

Endometrial cancer is one of the most common types of gynecological malignancy worldwide. Novel biomarkers and therapeutic targets are imperative for improving patients' survival. Previous studies have suggested the long non-coding RNA H19 as a potential cancer biomarker. To investigate the role of H19 in endometrial cancer, the present study examined the expression pattern of H19 in endometrial cancer tissues by quantitative polymerase chain reaction, and characterized its function in the endometrial cancer cell line via knocking down its expression with small interfering RNAs. It was found that H19 level was significantly higher in tumor tissues than in paratumoral tissues. Knockdown of H19 did not affect the growth rate of HEC-1-B endometrial cancer cells, but significantly suppressed in vitro migration and invasion of HEC-1-B cells. Furthermore, H19 downregulation decreased Snail level and increased E-cadherin expression without affecting vimentin level, indicating partial reversion of epithelial-mesenchymal transition (EMT). The present findings suggested that H19 contributed to the aggressiveness of endometrial cancer by modulating EMT process.

Long noncoding and circular RNAs in lung cancer: advances and perspectives

Better understanding and management of lung cancer are needed. Although much has been learned from known protein coding genes, long noncoding RNAs (lncRNAs), a relatively new and fast evolving large family of transcripts, have recently generated much attention for new discoveries. LncRNAs play critical regulatory functions and are emerging as new players in tumorigenesis and phenotypic determinators of lung cancer. In this review, we highlight the latest development of lncRNAs, including circular RNAs in lung cancer. We start with well-characterized lncRNAs and circular RNAs as an oncogene or tumor suppressor and then extend our discussion on the impact of SNPs in lncRNA on its functions and lung cancer risk and the clinical applications of lncRNAs as biomarkers and therapeutic targets.

miR675 upregulates long noncoding RNA H19 through activating EGR1 in human liver cancer

microRNAs (miRNAs) are short non-coding RNAs that are involved in post-transcriptional regulation of gene expression in multicellular organisms by affecting both the stability and translation of mRNAs. miR675, embedded in H19's first exon, had been linked to the development of human cancers. Herein, we demonstrate miR675 overexpression promotes and silencing miR675 attenuated liver cancer cell growth in vitro and in vivo. Mechanistically, miR675 inhibits the heterochromatin1 isoform HP1α expression in human liver cancer cells which causes a dramatically decrease of the total histone H3 lysine 9 trimethylation (H3K9me3) , histone H3 lysine 27 trimethylation (H3K27me3) and a increase of histone H3 lysine 27 acetylation(H3K27Ac).Notably, a significant reduction of the H3K9me3 and H3K27me3 and the increment of H3K27Ac occupancy on the promoter region of EGR1 triggers EGR1 transcription, translation, sumoylation and activation which upregulates lincRNA H19. Strikingly, H19 may induce and activate tumor-specific pyruvate kinase M2 (PKM2) which is essential for the Warburg effect in its dimer and for gene expression in its teramer during tumorigenesis. Our results imply that miR675 is involved in the epigenetic regulation of H3K9me3, H3k27me3 and H3K27Ac for gene expression and function during hepatocarcinogenesis (e.g.C-myc,Pim1,Ras,CyclinD1,RB1).These findings sheds light on the significance of miR675-HP1α-EGR1-H19-PKM2 cascade signaling pathway in liver cancer.

Long noncoding RNAs in digestive system cancers: Functional roles, molecular mechanisms, and clinical implications (Review)

Long noncoding RNAs (lncRNAs) are emerging as new players in various diseases including cancer. LncRNAs have been shown to play multifaceted roles in the development, progression, and metastasis of cancer. In this review, we highlight the lncRNAs that are critically involved in the pathogenesis of digestive system cancers (DSCs). We summarize the roles of the lncRNAs in DSCs and the underlying mechanisms responsible for their functions. The DSC-associated lncRNAs interact with a wide spectrum of molecules to regulate gene expression at transcriptional, post-transcriptional, and translational levels. We also provide new insights into the clinical significance of these lncRNAs, which are found to be closely associated with the aggressiveness of DSCs and could predict the prognosis of DSC patients. Moreover, lncRNAs have been suggested as promising therapeutic targets in DSCs. Therefore, better understanding of the functional roles of lncRNAs will provide new biomarkers for DSC diagnosis, prognosis, and therapy.

Long noncoding RNA dysregulation in ischemic heart failure

BACKGROUND

Long noncoding RNAs (lncRNAs) are non-protein coding transcripts regulating a variety of physiological and pathological functions. However, their implication in heart failure is still largely unknown. The aim of this study is to identify and characterize lncRNAs deregulated in patients affected by ischemic heart failure.

METHODS

LncRNAs were profiled and validated in left ventricle biopsies of 18 patients affected by non end-stage dilated ischemic cardiomyopathy and 17 matched controls. Further validations were performed in left ventricle samples derived from explanted hearts of end-stage heart failure patients and in a mouse model of cardiac hypertrophy, obtained by transverse aortic constriction. Peripheral blood mononuclear cells of heart failure patients were also analyzed. LncRNA distribution in the heart was assessed by in situ hybridization. Function of the deregulated lncRNA was explored analyzing the expression of the neighbor mRNAs and by gene ontology analysis of the correlating coding transcripts.

RESULTS

Fourteen lncRNAs were significantly modulated in non end-stage heart failure patients, identifying a heart failure lncRNA signature. Nine of these lncRNAs (CDKN2B-AS1/ANRIL, EGOT, H19, HOTAIR, LOC285194/TUSC7, RMRP, RNY5, SOX2-OT and SRA1) were also confirmed in end-stage failing hearts. Intriguingly, among the conserved lncRNAs, h19, rmrp and hotair were also induced in a mouse model of heart hypertrophy. CDKN2B-AS1/ANRIL, HOTAIR and LOC285194/TUSC7 showed similar modulation in peripheral blood mononuclear cells and heart tissue, suggesting a potential role as disease biomarkers. Interestingly, RMRP displayed a ubiquitous nuclear distribution, while H19 RNA was more abundant in blood vessels and was both cytoplasmic and nuclear. Gene ontology analysis of the mRNAs displaying a significant correlation in expression with heart failure lncRNAs identified numerous pathways and functions involved in heart failure progression.

CONCLUSIONS

These data strongly suggest lncRNA implication in the molecular mechanisms underpinning HF.

MiR-25 suppresses 3T3-L1 adipogenesis by directly targeting KLF4 and C/EBPα

In the past decade, miRNA emerges as a vital player in orchestrating gene regulation and maintaining cellular homeostasis. It is well documented that miRNA influences a variety of biological events, including embryogenesis, cell fate decision, and cellular differentiation. Adipogenesis is an organized process of cellular differentiation by which pre-adipocytes differentiate towards mature adipocytes. It has been shown that adipogenesis is tightly modulated by a number of transcription factors such as PPARγ, KLF4, and C/EBPα. However, the molecular mechanisms underlying the missing link between miRNA and adipogenesis-related transcription factors remain elusive. In this study, we unveiled that miR-25, a member of miR-106b-25 cluster, was remarkably downregulated during 3T3-L1 adipogenesis. Restored expression of miR-25 significantly impaired 3T3-L1 adipogenesis and downregulated the expression of serial adipogenesis-related genes. Further experiments presented that ectopic expression of miR-25 did not affect cell proliferation and cell cycle progression. Finally, KLF4 and C/EBPα, two key regulators of adipocyte differentiation, were experimentally identified as bona fide targets for miR-25. These data indicate that miR-25 is a novel negative regulator of adipocyte differentiation and it suppressed 3T3-L1 adipogenesis by targeting KLF4 and C/EBPα, which provides novel insights into the molecular mechanism of miRNA-mediated cellular differentiation.

Serum stress responsive gene EhslncRNA of Entamoeba histolytica is a novel long noncoding RNA

Non coding RNAs are known to play important roles in regulating gene expression at the transcriptional and posttranscriptional levels in metazoans. There is very little information available about non coding RNAs in protists such as Entamoeba histolytica. Antisense and micro RNAs have been reported in E. histolytica, however no long non coding RNAs has been reported yet. Here, we report our findings on an in vitro serum stress-inducible gene EhslncRNA, a member of B1 transmembrane kinase family of E. histolytica. EhslncRNA encodes a transcript of 2.6 kb and sequence analysis revealed that there is no ORF >150 bp within this transcript. The transcript was found to be polyadenylated and mainly associated with monosomes in the cytoplasm under serum starvation. In normal proliferating cells this RNA is mainly present in the nucleus. The promoter element was mapped between 437 to 346 nucleotides upstream of transcriptional start site and has both positive and negative regulatory elements. Deletion of the negative element converted the promoter to serum inducible type. Oxygen and heat stress also increased expression levels of EhslncRNA. These observations suggest that EhslncRNA may be a long non coding RNA and likely to help cells withstand stressful conditions in the host.

MiR675-5p Acts on HIF-1α to Sustain Hypoxic Responses: A New Therapeutic Strategy for Glioma

Hypoxia is a common feature in solid tumours. In glioma, it is considered the major driving force for tumour angiogenesis and correlates with enhanced resistance to conventional therapies, increased invasiveness and a poor prognosis for patients. Here we describe, for the first time, that miR675-5p, embedded in hypoxia-induced long non-coding RNA H19, plays a mandatory role in establishing a hypoxic response and in promoting hypoxia-mediated angiogenesis. We demonstrated, in vitro and in vivo, that miR675-5p over expression in normoxia is sufficient to induce a hypoxic moreover, miR675-5p depletion in low oxygen conditions, drastically abolishes hypoxic responses including angiogenesis. In addition, our data indicate an interaction of miR675-5p, HIF-1α mRNA and the RNA Binding Protein HuR in hypoxia-induced responses. We suggest the modulation of miR675-5p as a new therapeutic option to promote or abolish hypoxia induced angiogenesis.

Current Insights into Long Non-Coding RNAs in Renal Cell Carcinoma

Renal cell carcinoma (RCC) represents a deadly disease with rising mortality despite intensive therapeutic efforts. It comprises several subtypes in terms of distinct histopathological features and different clinical presentations. Long non-coding RNAs (lncRNAs) are non-protein-coding transcripts in the genome which vary in expression levels and length and perform diverse functions. They are involved in the inititation, evolution and progression of primary cancer, as well as in the development and spread of metastases. Recently, several lncRNAs were described in RCC. This review emphasises the rising importance of lncRNAs in RCC. Moreover, it provides an outlook on their therapeutic potential in the future.

Functions and Mechanisms of Long Noncoding RNAs in Ovarian Cancer

Long noncoding RNAs (lncRNAs) are longer than 200-nucleotide, noncoding transcripts in length, have a variety of biological functions, and are closely associated with tumor development. Ovarian cancer, as 1 of the 3 common gynecological malignancies, is the leading cause of death in women with gynecological malignant tumor. In this study, a review of the literature found that lncRNAs H19, LSINCT5, and XIST have a close relationship to the development of ovarian cancer occurrence, growth, invasion, and metastasis, and they can promote ovarian cancer cell proliferation. Hence, in this article, the progress of above-mentioned 3 kinds of lncRNAs in ovarian cancer was reviewed and designed to help in the diagnosis, treatment, and prognosis of ovarian cancer.

The role of the oncofetal H19 lncRNA in tumor metastasis: orchestrating the EMT-MET decision

Long non-coding RNA (lncRNA) genes are emerging as key players in the metastatic cascade. Current evidence indicate that H19 lncRNA and the microRNA(miRNA) miR-675, which is processed from it, play crucial roles in metastasis, through the regulation of critical events specifically the epithelial to mesenchymal (EMT) and the mesenchymal to epithelial transitions (MET). This review summarizes recent mechanistic pathways and tries to put together seemingly conflicting data from different reports under one proposed general scheme underlying the various roles of H19/miR-675 in the metastatic cascade. We propose several approaches to harnessing this knowledge for translational medicine.

Long Non-Coding RNAs in Endometrial Carcinoma

Endometrial carcinoma (EC), the second most common form of gynaecological malignancy, can be divided into two distinct sub-types: Type I tumours arise from hyperplastic endometrium and typically effect women around the time of menopause, whereas type II tumours arise in postmenopausal women from atrophic endometrium. Long non-coding RNAs (lncRNAs) are a novel class of non-protein coding molecules that have recently been implicated in the pathogenesis of many types of cancer including gynaecological tumours. Although they play critical physiological roles in cellular metabolism, their expression and function are deregulated in EC compared with paired normal tissue, indicating that they may also participate in tumour initiation and progression. For instance, the lncRNA MALAT-1 is down-regulated in EC samples compared to normal or hyperplastic endometrium, whereas the lncRNA OVAL is down-regulated in type II disease but up-regulated in type I disease. Other notatble lncRNAs such as HOTAIR, H19 and SRA become up-regulated with increasing EC tumour grade and other features associated with poor prognosis. In the current review, we will examine the growing body of evidence linking deregulated lncRNAs with specific biological functions of tumour cells in EC, we will highlight associations between lncRNAs and the molecular pathways implicated in EC tumourigenesis and we will identify critical knowledge gaps that remain to be addressed.

The H19 Long non-coding RNA in cancer initiation, progression and metastasis - a proposed unifying theory

The imprinted oncofetal long non-coding RNA (lncRNA) H19 is expressed in the embryo, down-regulated at birth and then reappears in tumors. Its role in tumor initiation and progression has long been a subject of controversy, although accumulating data suggest that H19 is one of the major genes in cancer. It is actively involved in all stages of tumorigenesis and is expressed in almost every human cancer. In this review we delineate the various functions of H19 during the different stages in the complex process of tumor progression. H19 up-regulation allows cells to enter a "selfish" survival mode in response to stress conditions, such as destabilization of the genome and hypoxia, by accelerating their proliferation rate and increasing overall cellular resistance to stress. This response is tightly correlated with nullification, dysfunction or significant down-regulation of the master tumor suppressor gene P53. The growing evidence of H19's involvement in both proliferation and differentiation processes, together with its involvement in epithelial to mesenchymal transition (EMT) and also mesenchymal to epithelial transition (MET), has led us to conclude that some of the recent disputes and discrepancies arising from current research findings can be resolved from a viewpoint supporting the oncogenic properties of H19. According to a holistic approach, the versatile, seemingly contradictory functions of H19 are essential to, and differentially harnessed by, the tumor cell depending on its context within the process of tumor progression.