Exosomal long noncoding RNA lnc-GNAQ-6:1 may serve as a diagnostic marker for gastric cancer

BACKGROUND

Gastric cancer (GC) is one of the most aggressive cancers, with limited early diagnostic measures. Tumor-originated exosomal molecules are regarded as suitable candidates for non-invasive diagnosis. This study aimed to investigate the capacity of exosomal long noncoding RNA lnc-GNAQ-6:1 as a biomarker for early diagnosis of GC.

METHODS

In this study, we collected sera from 43 patients with gastric cancer and 27 healthy subjects, then exosomes were isolated using commercial kits. Particle size analysis, Western bloting and protein-based exosomes quantification were conducted to identify the isolated exosomes and to evaluate its yield and purity. Expression levels of exosomal lnc-GNAQ-6:1 were detected by quantitative reverse transcription PCR (qRT-PCR). The serum concentrations of traditional biomarker (CA72-4, CEA, and CA19-9) were measured via a chemiluminescent detection system.The receiver operating characteristic curve (ROC) and area under curve (AUC) were used to estimate the diagnostic capacity. Furthermore, we analyzed the potential relationship between serum exosomal lnc-GNAQ-6:1 expression and clinicopathological parameters of gastric cancer.

RESULTS

The exosomes extracted in this study exhibited the typical exosome characteristics and purity. Patients with gastric cancer had the higher exosome yield than healthy volunteer. The results of qRT-PCR showed that compared with the healthy control, the expression of lnc-GNAQ-6:1 was significantly lower in the gastric cancer group. The area under the ROC curve is 0.732, which was higher than the diagnostic accuracy of CEA, CA 19-9 and CA72-4. However, the expression level of lnc-GNAQ-6:1 was not correlated with gender, age, tumor metastasis, serum carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), and carbohydrate antigen 72-4(CA72-4).

CONCLUSIONS

Our data demonstrated that serum exosomal lnc-GNAQ-6:1 is lowly expressed in patient with gastric cancer and might be evaluated in larger studies as a new diagnostic marker for gastric cancer.

Exosomes: Nanocarriers of Biological Messages

Cell-cell communication is crucial to maintain homeostasis in multicellular organism. Cells communicate each other by direct contact or by releasing factors that, soluble or packaged in membrane vesicles, can reach different regions of the organism. To date numerous studies highlighted the existence of several types of extracellular vesicles that, differing for dimension, origin and contents, play a role in physiological and/or pathological processes. Among extracellular vesicles, exosomes are emerging as efficient players to modulate target cells phenotype and as new non-invasive diagnostic and prognostic tools in multiple diseases. They, in fact, strictly reflect the type and functional status of the producing cells and are able to deliver their contents even over a long distance. The results accumulated in the last two decades and collected in this chapter, indicated that exosomes, can carry RNAs, microRNAs, long non-coding RNAs, DNA, lipids, metabolites and proteins; a deeper understanding of their contents is therefore needed to get the most from this incredible cell product.

Expression and mechanism of exosome-mediated A FOXM1 related long noncoding RNA in gastric cancer

BACKGROUND

Forkhead box protein M1 (FOXM1) is an oncogene regulating tumor growth and metastasis. Exosome was suggested to mediate cell communication by delivering active molecules in cancers. However, the existence of FOXM1 in circulating exosomes and the role of exosome FOXM1 in gastric cancer (GC) were not clear. This study aims to investigate the potential role of FOXM1 related long noncoding RNA (FRLnc1) in exosomes in GC.

RESULTS

The prepared CD63 immunomagnetic beads (CD63-IMB) had the characteristics of good dispersity and high magnetic response. The isolated exosomes were presented with elliptical membranous particles under a transmission electron microscope (TEM), with the particle size of 89.78 ± 4.8 nm. Western blot (WB) results showed that the exosomes were rich in CD9 and CD81. The Dil-labeled exosomes were distributed around cytoplasm and nucleus of cells by imaging flow cytometry (IFC) analysis. The results of quantitative real-time PCR (qRT-PCR) revealed that the FRLnc1 expressions were up-regulated in GC cells, tumor tissues, and serum of GC patients. An obviously up-regulated FRLnc1 expression was found in serum exosomes of GC patients. Up-regulation of FRLnc1 expression was closely correlated to lymph node metastasis (LNM) and TNM stage with the combination of relevant clinicopathological parameter analysis. The in vitro functional analyses demonstrated that FRLnc1 knockdown by RNA interference suppressed cell proliferation and migration in HGC-27 cells, whereas FRLnc1 overexpression promoted cell proliferation and migration in MKN45 cells. After exosome treatment, the FRLnc1 expression was significantly increased in MKN45 cells, and the MKN45 cells showed increased ability of proliferation and migration.

CONCLUSION

GC cells-derived exosomes played roles in promoting the growth and metastasis of GC by transporting FRLnc1, suggesting that FRLnc1 in the exosomes may be a potential biomarker for the diagnosis and treatment of GC. The delivery of FRLnc1 by the exosomes may provide a new way for the treatment of GC. Trial registration 2020-KYSB-094. Registered 23 March 2020-Retrospectively registered.

Non Coding RNA Molecules as Potential Biomarkers in Breast Cancer

The pursuit of minimally invasive biomarkers is a challenging but exciting area of research. Clearly, such markers would need to be sensitive and specific enough to aid in the detection of breast cancer at an early stage, would monitor progression of the disease, and could predict the individual patient's response to treatment. Unfortunately, to date, markers with such characteristics have not made it to the clinic for breast cancer. Past years, many studies indicated that the non-coding part of our genome (the so called 'junk' DNA), may be an ideal source for these biomarkers. In this chapter, the potential use of microRNAs and long non-coding RNAs as biomarkers will be discussed.

Epigenetic targeting of autophagy for cancer prevention and treatment by natural compounds

Despite the undeniable progress made in the last decades, cancer continues to challenge the scientists engaged in searching for an effective treatment for its prevention and cure. One of the malignant hallmarks that characterize cancer cell biology is the altered metabolism of sugars and amino acids. Autophagy is a pathway allowing the macromolecular turnover via recycling of the substrates resulting from the lysosomal degradation of damaged or redundant cell molecules and organelles. As such, autophagy guarantees the proteome quality control and cell homeostasis. Data from in vitro, in animals and in patients researches show that dysregulation of autophagy favors carcinogenesis and cancer progression, making this process an ineluctable target of cancer therapy. The autophagy process is regulated at genetic, epigenetic and post-translational levels. Targeting autophagy with epigenetic modifiers could represent a valuable strategy to prevent or treat cancer. A wealth of natural products from terrestrial and marine living organisms possess anti-cancer activity. Here, we review the experimental proofs demonstrating the ability of natural compounds to regulate autophagy in cancer via epigenetics. The hope is that in the near future this knowledge could translate into effective intervention to prevent and cure cancer.

Long non coding RNA XIST as a prognostic cancer marker - A meta-analysis

BACKGROUND

The X inactivate-specific transcript (XIST), derived from XIST gene, is aberrantly expressed in various cancers. High-expression of XIST is related to poor clinical outcome. This meta-analysis evaluated the potential role of XIST as novel predictor of prognosis in human cancer.

MATERIALS AND METHODS

This meta-analysis collected eligible studies about XIST and tumor prognosis through retrieving keywords in Web of Science, PubMed, Embase and the CNKI database, from 1993 to August 21, 2017. The quantitative meta-analysis was carried out with Stata SE12.0 and RevMan3.23 software. The aim was to determine whether XIST expression is associated with cancer prognosis and clinicopathology.

RESULTS

A total of 858 patients from 10 eligible studies were included in the final meta-analysis. Overall, a significant negative association between XIST and overall survival (OS) time (HR = 2.62, 95% CI: 2.18-3.14) was observed. Statistical significance was also showed in subgroup meta-analysis stratified by the country, sample size, follow-up and publication year. It was reported that increased XIST was positively related to advanced clinical TNM stage (OR = 4.03, 95% CI: 2.22-7.30), lymph node metastasis (LNM) (OR = 2.70, 95% CI: 1.73-4.21), distant metastasis (DM) (OR = 2.61, 95% CI: 1.57-4.33) and tumor size (OR = 3.10, 95% CI: 2.24-4.30).

CONCLUSIONS

LncRNA XIST may serve as a potential biomarker to predict solid tumor prognosis. This molecule can be effectively used to predict the clinical and pathological features of cancers.

Long non-coding RNA PVT1 as a novel candidate for targeted therapy in hematologic malignancies

Cancerous cells show resistance to various forms of therapy, so applying up to the minute targeted therapy is crucial. For this purpose, long non-coding RNA PVT1 as shown by recent studies is an important oncogene that interacts with vital cellular signaling pathways and different proteins such as c-Myc, NOP2 and LATS2. Due to the enormous role of long non-coding RNAs in development of leukemias, we aimed to show the role of PVT1 knock-down on fate of different hematologic cell lines. owing to this matter, various experiments such as Real-time PCR, cell cycle analysis and apoptosis assay were performed. Meanwhile, proliferation rate by CFSE, protein expression of c-Myc and hTERT by western blot and flow cytometry analysis were investigated. Our results demonstrated that PVT1 knock-down results in c-Myc degradation, proliferation down-regulation, induction of apoptosis and G0/G1 arrest. Simultaneously, for the first time, we posited the relation between this oncogene with hTERT that reduced after PVT1 knock-down. Considering these results, long non-coding RNA PVT1 may be a potential option for targeted therapy in hematologic malignancies.

Retrotransposons in pluripotent cells: Impact and new roles in cellular plasticity

Transposable Elements are pieces of DNA able to mobilize from one location to another within genomes. Although they constitute more than 50% of the human genome, they have been classified as selfish DNA, with the only mission to spread within genomes and generate more copies of themselves that will ensure their presence over generations. Despite their remarkable prevalence, only a minor group of transposable elements remain active in the human genome and can sporadically be associated with the generation of a genetic disorder due to their ongoing mobility. Most of the transposable elements identified in the human genome corresponded to fixed insertions that no longer move in genomes. As selfish DNA, transposable element insertions accumulate in cell types where genetic information can be passed to the next generation. Indeed, work from different laboratories has demonstrated that the main heritable load of TE accumulation in humans occurs during early embryogenesis. Thus, active transposable elements have a clear impact on our pluripotent genome. However, recent findings suggest that the main proportion of fixed non-mobile transposable elements might also have emerging roles in cellular plasticity. In this concise review, we provide an overview of the impact of currently active transposable elements in our pluripotent genome and further discuss new roles of transposable elements (active or not) in regulating pluripotency. This article is part of a Special Issue entitled: Stress as a fundamental theme in cell plasticity.

shRNA targeting of ferritin heavy chain activates H19/miR-675 axis in K562 cells

PURPOSE

The heavy subunit of the iron storage protein ferritin (FHC) is essential for the intracellular iron metabolism and, at the same time, it represents a central hub of iron-independent pathways, such as cell proliferation, angiogenesis, p53 regulation, chemokine signalling, stem cell expansion, miRNAs expression. In this work we have explored the ability of FHC to modulate gene expression in K562 cells, through the up-regulation of the lncRNA H19 and its cognate miR-675.

MATERIALS AND METHODS

Targeted silencing of FHC was performed by lentiviral-driven shRNA strategy. FHC reconstitution was obtained by full length FHC cDNA transfection with Lipofectamine 2000. ROS amounts were determined with the redox-sensitive probe H2DCFDA. H19, miR-675, miR-107, Twist1, ID3, EPHB6, GNS, ANK1 and SMAD6 mRNA amounts were quantified by Taqman assay and qPCR analysis.

RESULTS

FHC silencing in K562 cells modulates gene expression through the up-regulation of the lncRNA H19 and its cognate miR-675. Experimental findings demonstrate that the molecular mechanism underlying this phenomenon is represented by an FHC knock-down-triggered increase in reactive oxygen species (ROS) production.

CONCLUSIONS

In this paper we uncover a so far not described function of the ferritin heavy subunit in the control of lncRNA pathways.

Long non-coding RNAs in the gastric juice of gastric cancer patients

Differently from other digestive malignancies, gastric cancer (GC) carcinogenesis seems more heterogeneous and unclear. This entails failing in identification of reliable serum tumor markers for screening early GC (EGC) as well as persisting ominous prognosis of this disease. Recently, investigation of human noncoding genome, especially long noncoding molecules (lncRNAs), has provided promising data. As for GC, however, since the current information on GC-specific lncRNAs is still scarce and comes largely from analyses performed on tissue or serum of affected patients, we decided to review the current literature dealing with expression of such molecules in the gastric juice (GJ) of GC patients. In the case of GC, in fact, several cytological and molecular works have already demonstrated GJ to be an interesting biological material for improving clinicopathologic and prognostic knowledge of this cancer. For this review, we burrowed into the literature on lncRNAs expressed in GJ of GC patients. PubMed, Science Direct, Scopus, Web of Science, Google Scholar and ResearchGate were the search engines entertained. As of 2018, only seven studies have been reported. LINC00152, AA174084, UCA1, RMRP, ABHD11-AS1, LINC00982 and H19 were the GJ lncRNAs examined. Following our review, we can conclude that, due to their high specificity and reliability, GJ lncRNAs should deserve a prominent role in the field of GC research: importantly, they could be used for screening EGC, ameliorating the existing methods of staging (which are still far from being completely accurate), improving the prognostic capacity of the current diagnostic armamentarium and, finally, providing new and valuable therapeutic targets.

Long noncoding RNA LINC01510 promotes the growth of colorectal cancer cells by modulating MET expression

Background

Abnormal expression of long non-coding RNA (lncRNAs) often facilitates unrestricted growth of cancer cells. Long intergenic non-protein coding RNA 1510, an enhancer lncRNA (LINC01510), a lncRNA enhancer is upregulated in colorectal cancer (CRC), and its expression might relate to MET as revealed by lncRNA microarray data. However, the potential biological role of LINC01510 and its regulatory mechanism in CRC remain unclear. Therefore, we investigated the involvement of LINC01510 in the proliferation of CRC cells.

Methods

Microarray analysis, In situ hybridization, colony formation assay, MTT assay, Western blotting, quantitative RT-PCR and flow cytometry were applied. The two-tailed Student’s t test and analysis of variance or general linear model of single factor variable was used for statistical analyse.

Results

In the present study, we found that LINC01510 was significantly upregulated in CRC tissues and cell lines. The LINC01510 expression level were associated with the clinicopathological grade and stage. Meanwhile, gain- and loss-of-function assays demonstrated that LINC01510 overexpression increased CRC cell proliferation, and promoted cell cycle progression from the G1 phase to the S phase. Further study indicated that LINC01510 was positively correlated with the expression of MET, and its effects were most likely at the transcriptional level.

Conclusions

Taken together, our findings suggested that upregulation of LINC01510 contributes to the proliferation of CRC cells, at least in part, through the regulation of MET protein. LINC01510 could be a candidate prognostic biomarker and a target for new therapies in CRC patients.

Vitamin D regulation of and by long non coding RNAs

Two percent or less of the genome is used to transcribe mRNAs encoding proteins. Nearly all the remainder is utilized in transcribing non coding RNAs, the bulk of which are RNAs at least 200 base in length, long non coding RNAs (lncRNA). Their number is estimated to be about 28,000, but only a small fraction of lncRNAs are well characterized. That said lncRNAs have been found to regulate a very diverse array of biochemical and genomic functions. One of the transcription factors found to be regulated by and to regulate lncRNA is the vitamin D receptor (VDR). Like lncRNAs VDR is involved in the regulation of numerous biochemical and genomic processes, so it is not surprising that there would be a number of interactions between lncRNAs and VDR in their diverse functions. However, the study of these interactions is in its infancy. To date most attention has been paid to their interactions in cancer. Our own studies have focused on non melanoma skin cancers, keratinocyte carcinomas to be precise. Deletion of VDR from keratinocytes predisposes them to malignant transformation. Among a number of potential mechanisms we found that VDR deletion from these cells alters the lncRNA profile to a more oncogenic configuration, increasing the expression of well known oncogenic lncRNAs and decreasing the expression of well known tumor suppressor lncRNAs. Subsequent studies in other cancers have found similar associations between VDR and oncogenic lncRNAs with evidence of tumor specificity. To date these studies primarily reveal associations rather than causality, but causal links should be expected as research in this field continues to develop.

D-4F decreases the expression of Aβ protein through up-regulating long non coding RNA sirt1-as in SAMP8 mice

Cholesterol plays key roles on (Aβ) metabolism and production. D-4F is the apolipoprotein A-I mimetic peptide which has been revealed a critical role in regulation cholesterol. We aimed at identifying the effects of D-4F on Aβ production in SAMP8 and the underlying mechanisms.

METHODS

SAMP8 mice (n = 15) were randomized into three groups for treatment with D-4F given in drinking water: high-dose group (0.5 mg/ml), low-dose group (0.3 mg/ml) and control group (just drinking water). The heart, kidney, liver and brain were obtained from SAMP8 (9 of them included in the analysis). The long non-coding RNA sirt1-as was measured in all tissues. The immunohistochemistry, western blot qRT-PCR were performed to determine the sirt1-as and the relevant proteins or RNAs levels.

RESULTS

After treated with D-4F, the sirt1-as has been significantly upregulated in brain, rather than heart, kidney or liver. Specially, sirt1-as was significantly up-regulated by high dose of D-4F in the hippocampus area (p = 0.007) compared with control group. Further analysis revealed that D-4F up-regulates the expression of SIRT1. We also found that D-4F treatment significantly increased the reverse cholesterol transport related proteins liver X receptor α (LXRα) and ATP-binding cassette transporter A1 (ABCA1, p < 0.05). Finally, the amyloid β-protein (Aβ protein) was statistically lower than that in the control group (p < 0.05).

CONCLUSION

Our observation indicated that D-4F decreases the expression of Aβ protein through up-regulating long non coding RNA sirt1-as and its downstream proteins which may involve in reverse cholesterol transport.

Hypoxia related long non-coding RNAs in ischemic stroke

With high rates of mortality and disability, stroke has caused huge social burden, and 85% of which is ischemic stroke. In recent years, it is a progressive discovery of long non-coding RNA (lncRNA) playing an important regulatory role throughout ischemic stroke. Hypoxia, generated from reduction or interruption of cerebral blood flow, leads to changes in lncRNA expression, which then influence disease progression. Therefore, we reviewed studies on expression of hypoxia-related lncRNAs and relevant molecular mechanism in ischemic stroke. Considering that hypoxia-inducible factor (HIF) is a crucial regulator in hypoxic progress, we mainly focus on the HIF-related lncRNA which regulates the expression of HIF or is regulated by HIF, further reveal their pathogenesis and adaption after brain ischemia and hypoxia, so as to find effective biomarker and therapeutic targets.

Identification of Long Noncoding RNA by In Situ Hybridization Approaches

In situ hybridization (ISH) and fluorescence in situ hybridization (FISH) techniques enable us to detect the expression of a specific RNA in fixed cells or tissue sections. Here, we describe in detail two procedures adjusted to reveal specifically lncRNAs in normal human keratinocytes and in skin tissue samples. Examples of the results obtained by the two different approaches are also shown.

LncRNA HMlincRNA717 is down-regulated in non-small cell lung cancer and associated with poor prognosis

INTRODUCTION

Long non coding RNAs (lncRNAs) have emerged recently as major players in tumor biology and may be used for cancer diagnosis, prognosis, and potential therapeutic targets. The lncRNA HMlincRNA717, a newly identified lncRNA, was demonstrated to be down-regulated in gastric cancer. However, little is known about its role in non small cell lung cancer (NSCLC).

METHODS

Expression of lncRNA HMlincRNA717 in tumor and their matched non-tumor tissues was determined by quantitative real-time PCR (qRT-PCR) in NSCLC patients. Then, we analyzed the potential relationship between lncRNA HMlincRNA717 expression levels in tumor tissues and clinicopathological features of NSCLC, and clinical outcome.

RESULTS

lncRNA HMlincRNA717 expression level was significantly decreased in NSCLC tissues in comparison to adjacent non-tumor tissues. It was also proved that HMlincRNA717 expression was to be associated with NSCLC histological grade, and lymph node metastasis. In addition, survival analysis proved that down-regulated HMlincRNA717 expression was associated with poor overall survival of NSCLC patients. Multivariate survival analysis also proved that HMlincRNA717 was an independent prognostic factor for NSCLC patients.

CONCLUSIONS

The present study showed the down-regulation of HMlincRNA717 and its association with tumor progression in human NSCLC. It also provided that HMlincRNA717 expression was an independent prognostic factor for patients with NSCLC, which might be a potential prognostic biomarker and therapeutic target for NSCLC.

Long non-coding RNA HOTAIR: A biomarker and therapeutic target in urological tumors

Long non-coding RNAs (lncRNAs) significantly influence gene regulation across epigenetic, transcriptional, and post-transcriptional levels through their interactions with DNA, RNA, and proteins. There is growing evidence of lncRNAs' critical roles in the emergence and progression of various diseases, including urological tumors (UTs), such as cancers of the kidney, bladder, and prostate. Research increasingly links lncRNA dysregulation to diverse cellular processes like invasion, metastasis, apoptosis, and chromatin remodeling. Among these, HOTAIR stands out for its pivotal role in oncogenesis, impacting treatment resistance, cell migration, proliferation, survival, and genomic integrity. This review provides an overview of HOTAIR's functions, its identification, and its biological significance. Furthermore, it delves into HOTAIR's involvement in UTs, underlining its potential as a therapeutic target and biomarker for innovative approaches to treating these cancers.

LncRNA HOXB-AS3 promotes proliferation, migration, and invasion of gallbladder cancer cells by activating the MEK/ERK pathway

Background

LncRNA HOXB-AS3 are associated with tumor progression in several types of carcinomas, yet, its possibly biological role in gallbladder carcinoma(GBC) remains unclear. Therefore, this study aimed to investigate the biological function of HOXB-AS3 in GBC.

Methods

To know the potential function of HOXB-AS3 in gallbladder carcinoma, real-time polymerase chain reaction was used to detected the expression of HOXB-AS3 in gallbladder carcinoma cells. The colony formation assay and cell counting kit-8 assay was performed to measured cell viability. Flow cytometry was to analyse cell apoptosis and cell cycle. Cell invasion and migration were determined by the transwell invasion assay and wound-healing assay. A nude mice xenograft tumor model was performed to investigate the biological function of HOXB-AS3 in vivo.

Results

The results indicated that HOXB-AS3 was significantly elevated in gallbladder carcinoma tissues and cell lines. We used siHOXB-AS3 to knockdown the expression levels of HOXB-AS3. And knockdown HOXB-AS3 expression depressed gallbladder cancer cell viability and induced cell apoptosis. In addition, the gallbladder carcinoma cell cycle was obviously arrested at the G1 phase. Cell invasion and migration were markedly suppressed following knockdown HOXB-AS3 expression. Furthermore, the features of siHOXB-AS3 in gallbladder cancer cells could be reversed by the ERK1/2 phosphorylation agonist Ro 67-7476. Finally, we confirmed that HOXB-AS3 promoted the growth of transplanted tumors in vivo.

Conclusion

HOXB-AS3 promoted gallbladder carcinoma cell proliferation, invasion and migration by activating the MEK/ERK signaling pathway. HOXB-AS3 contributed to gallbladder cancer tumorigenesis and metastasis, making it a viable therapeutic target for gallbladder cancer treatment.