Long non-coding RNA UFC1 promotes gastric cancer progression by regulating miR-498/Lin28b

Suppression of hepatocellular carcinoma progression by long noncoding RNA apolipoprotein C1 pseudogene via the regulation of the microRNA-106b-PTEN axis

Background

Numerous researches have reported that long noncoding RNAs (lncRNAs) participate in tumor development and progression. LncRNA apolipoprotein C-I pseudogene 1 (APOC1P1), a pseudogene located in 19q13.2 between apolipoprotein C-I and apolipoprotein C-IV, is involved in a variety of diseases. However, the role of lncRNA APOC1P1 in hepatocellular carcinoma (HCC) remains unknown.

Methods

Quantitative polymerase chain reaction (qPCR) was performed to examine the expression of APOC1P1, miR-106b, and PTEN (phosphatase and TENsin homolog deleted on chromosome 10) in HCC tissues, adjacent normal tissues, and specific cell lines (LO2, Bel-7407, HCCLM3, MHCC-97H, Hep G2, and Huh-7). Upregulation of APOC1P1 and downregulation of miR-106b were conducted via application of vector transfection and microRNA (miRNA) inhibitor. Bioinformatics analysis and luciferase reporter assay were used to verify the binding sites of APOC1P1, miR-106b, and PTEN. Cell proliferation and invasion were determined with Cell Counting Kit-8 (CCK-8) and Transwell experiments. Subcellular location analysis was used to determine the distribution of APOC1P1 in cells, and Western blotting was used to detect the expression of PTEN.

Results

It was found that the expressions of APOC1P1 and PTEN were downregulated, while that of miR-106b was upregulated in HCC tissues and cells. Subcellular location analysis showed that APOC1P1 was localized in cytoplasm and competitively bound to miR-106b. APOC1P1 overexpression and miR-106b inhibition suppressed HCC cell proliferation and invasion. qPCR indicated the negative correlation between APOC1P1 expression and miR-106b expression in HCC tissues and a positive correlation between APOC1P1 and PTEN.

Conclusions

Our findings suggested that the lncRNA APOC1P1 inhibits HCC progression by competitively binding to miR-106b, leading to elevated PTEN expression, inhibiting cell proliferation and invasion in HCC cells. These results provide new insights into the diagnosis and therapy of HCC.

Connection of Cancer Exosomal LncRNAs, Sponging miRNAs, and Exosomal Processing and Their Potential Modulation by Natural Products

Cancerous exosomes contain diverse biomolecules that regulate cancer progression. Modulating exosome biogenesis with clinical drugs has become an effective strategy for cancer therapy. Suppressing exosomal processing (assembly and secretion) may block exosomal function to reduce the proliferation of cancer cells. However, the information on natural products that modulate cancer exosomes lacks systemic organization, particularly for exosomal long noncoding RNAs (lncRNAs). There is a gap in the connection between exosomal lncRNAs and exosomal processing. This review introduces the database (LncTarD) to explore the potential of exosomal lncRNAs and their sponging miRNAs. The names of sponging miRNAs were transferred to the database (miRDB) for the target prediction of exosomal processing genes. Moreover, the impacts of lncRNAs, sponging miRNAs, and exosomal processing on the tumor microenvironment (TME) and natural-product-modulating anticancer effects were then retrieved and organized. This review sheds light on the functions of exosomal lncRNAs, sponging miRNAs, and exosomal processing in anticancer processes. It also provides future directions for the application of natural products when regulating cancerous exosomal lncRNAs.

LOC101929709 promotes gastric cancer progression by aiding LIN28B to stabilize c-MYC mRNA

BACKGROUND

LIN28B plays a critical role in the Warburg effect. However, its underlying mechanism remains elusive. Recently, it has been reported that LIN28B could collaborate with IGF2BP3, which can bind to m6A-modified c-MYC transcripts. Therefore, this study investigated if LIN28B recognises methylated c-MYC mRNA to promote the Warburg effect in gastric cancer.

METHODS

Effects of LIN28B on gastric cancer were confirmed in vitro and in vivo. On the basis of bioinformatics analysis, the association between LIN28B and c-MYC mRNA was shown using RNA immunoprecipitation (RIP) and luciferase reporter assays. The role of m6A was identified by RNA pull-down assays. We further performed RIP-seq to search for long non-coding RNAs (lncRNAs) participating in the LIN28B binding process. Chromatin immunoprecipitation was used to show the impact of c-MYC on transcription of LIN28B and lncRNAs.

RESULTS

LIN28B was identified to stabilize c-MYC mRNA by recognizing m6A. Furthermore, the interaction between c-MYC mRNA and LIN28B is speculated to be supported by LOC101929709, which binds to both LIN28B and IGF2BP3. Functional experiments revealed that LOC101929709 promotes the proliferation, migration and glycolysis of gastric cancer. Mechanistically, LOC101929709 enriched in the cytoplasm helps LIN28B stabilize c-MYC mRNA. Moreover, c-MYC promoted the transcription of both LOC101929709 and LIN28B. Additionally, LOC101929709 also activated the PI3K/AKT pathway.

CONCLUSIONS

The c-MYC/LOC101929709/LIN28B axis promotes aerobic glycolysis and tumour progression. Thus, LOC101929709 can be a novel potential target for gastric cancer treatment.

Exosomal lncRNAs in gastrointestinal cancer

Gastrointestinal cancer (GIC) remains a leading cause of morbidity and mortality worldwide. Unfortunately, these cancers are diagnosed in advanced metastatic stages due to lack of reliable biomarkers that are sufficiently specific and sensitive in early disease. There has been growing evidence that circulating exosomes can be used to diagnose cancer non-invasively with limited risks and side effects. Furthermore, exosomal long non-coding RNAs (lncRNAs) are emerging as a new class of promising biomarkers in cancer. This review provides an overview of the extraction and detection of exosomal lncRNAs with a focus on their potential role in GIC.

Exosome-mediated lnc-ABCA12-3 promotes proliferation and glycolysis but inhibits apoptosis by regulating the toll-like receptor 4/nuclear factor kappa-B signaling pathway in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a kind of malignant tumor with high incidence and mortality in the digestive system. The aim of this study is to explore the function of lnc-ABCA12-3 in the development of ESCC and its unique mechanisms. RT-PCR was applied to detect gene transcription levels in tissues or cell lines like TE-1, EC9706, and HEEC cells. Western blot was conducted to identify protein expression levels of mitochondrial apoptosis and toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB) signaling pathway. CCK-8 and EdU assays were carried out to measure cell proliferation, and cell apoptosis was examined by flow cytometry. ELISA was used for checking the changes in glycolysis-related indicators. Lnc-ABCA12-3 was highly expressed in ESCC tissues and cells, which preferred it to be a candidate target. The TE-1 and EC9706 cells proliferation and glycolysis were obviously inhibited with the downregulation of lnc-ABCA12-3, while apoptosis was promoted. TLR4 activator could largely reverse the apoptosis acceleration and relieved the proliferation and glycolysis suppression caused by lnc-ABCA12-3 downregulation. Moreover, the effect of lnc-ABCA12-3 on ESCC cells was actualized by activating the TLR4/NF-κB signaling pathway under the mediation of exosome. Taken together, the lnc-ABCA12-3 could promote the proliferation and glycolysis of ESCC, while repressing its apoptosis probably by regulating the TLR4/NF-κB signaling pathway under the mediation of exosome.

CEACAM5 targeted by miR-498 promotes cell proliferation, migration and epithelial to mesenchymal transition in gastric cancer

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CEACAM5 was upregulated in GC tissues and cells.

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CEACAM5 knockdown repressed GC cell migration, proliferation, and EMT.

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Knockdown of CEACAM5 suppressed the growth of GC cells in mice with transplanted tumor.

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CEACAM5 was predicted as a miR-498 target.

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MiR-498 reduced GC cell migration, proliferation, and EMT by inhibiting CEACAM5.

Objective

Recent studies have shown that carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5) may serve as an independent predictor of advanced gastric cancer (GC). The purpose of this research is to explore the patterns of expression, functions, and upstream regulatory pathway of CEACAM5 in GC.

Methods

The levels of miR-498 and CEACAM5 expression in GC cells and tissues were measured via qRT-PCR. Wound-healing, CCK-8, and western blotting experiments were conducted for the evaluation of GC cell migration, proliferation, and epithelial-mesenchymal transition (EMT), respectively. The targeting relationship between miR-498 and CEACAM5 was validated via pull-down and luciferase reporter assays. Xenograft tumor mouse models were established to observe CEACAM5’s influence on the growth of tumors in vivo.

Results

Elevated levels of CEACAM5 were detected among the GC cells and tissues. The results of the in vitro experiments revealed that the knockdown of CEACAM5 in GC cells significantly inhibited their proliferation, migration, and EMT. Moreover, CEACAM5 inhibition effectively hampered GC cell growth within the nude mice. Moreover, miR-498 directly targeted CEACAM5. MiR-498 downregulation had been observed among the cells and tissues of GC. The stimulation of GC cell proliferation, migration, and EMT, which had been engendered by CEACAM5 overexpression, was reversible through the overexpression of miR-498.

Conclusion

The outcomes of this research suggest that miR-498 is capable of repressing the proliferation, migration, and EMT of GC cells through CEACAM5 downregulation.

UFMylation System: An Emerging Player in Tumorigenesis

Simple Summary

The ubiquitin-fold modifier 1 (UFM1) is a newly identified post-translational modification protein that has been implicated in multiple cellular processes and diseases. Noticeably, an aberrant UFM1 modification system has been closely related to various types of tumorigeneses, implying that the restoration of UFMylation homeostasis may serve as a promising therapeutic strategy. In this review, we summarize the structure, process and biological functions of the UFM1 modification system. In particular, we discuss the relationship between the UFMylation system and tumorigenesis, illustrating the underlying mechanisms and future perspectives. This article aims to improve our understanding of UFM1 modification, as well as provide some new strategies for cancer treatment.

Abstract

Ubiquitin-fold modifier 1 (UFM1), a newly identified ubiquitin-like molecule (UBLs), is evolutionarily expressed in multiple species except yeast. Similarly to ubiquitin, UFM1 is covalently attached to its substrates through a well-orchestrated three-step enzymatic reaction involving E1, the UFM1-activating enzyme (ubiquitin-like modifier-activating enzyme 5, UBA5); E2, the UFM1-conjugating enzyme 1 (UFC1); and E3, the UFM1-specific ligase 1 (UFL1). To date, numerous studies have shown that UFM1 modification is implicated in various cellular processes, including endoplasmic reticulum (ER) stress, DNA damage response and erythroid development. An abnormal UFM1 cascade is closely related to a variety of diseases, especially tumors. Herein, we summarize the process and functions of UFM1 modification, illustrating the relationship and mechanisms between aberrant UFMylation and diversified tumors, aiming to provide novel diagnostic biomarkers or therapeutic targets for cancer treatments.

Prediction of Response to Radiotherapy by Characterizing the Transcriptomic Features in Clinical Tumor Samples across 15 Cancer Types

Purpose

Radiotherapy (RT) is one of the major cancer treatments. However, the responses to RT vary among individual patients, partly due to the differences of the status of gene expression and mutation in tumors of patients. Identification of patients who will benefit from RT will improve the efficacy of RT. However, only a few clinical biomarkers were currently used to predict RT response. Our aim is to obtain gene signatures that can be used to predict RT response by analyzing the transcriptome differences between RT responder and nonresponder groups.

Materials and Methods

We obtained transcriptome data of 1664 patients treated with RT from the TCGA database across 15 cancer types. First, the genes with a significant difference between RT responder (R group) and nonresponder groups (PD group) were identified, and the top 100 genes were used to build the gene signatures. Then, we developed the predictive model based on binary logistic regression to predict patient response to RT.

Results

We identified a series of differentially expressed genes between the two groups, which are involved in cell proliferation, migration, invasion, EMT, and DNA damage repair pathway. Among them, MDC1, UCP2, and RBM45 have been demonstrated to be involved in DNA damage repair and radiosensitivity. Our analysis revealed that the predictive model was highly specific for distinguishing the R and PD patients in different cancer types with an area under the curve (AUC) ranging from 0.772 to 0.972. It also provided a more accurate prediction than that from a single-gene signature for the overall survival (OS) of patients.

Conclusion

The predictive model has a potential clinical application as a biomarker to help physicians create optimal treatment plans. Furthermore, some of the genes identified here may be directly involved in radioresistance, providing clues for further studies on the mechanism of radioresistance.

Emerging Advances of Detection Strategies for Tumor-Derived Exosomes

Exosomes derived from tumor cells contain various molecular components, such as proteins, RNA, DNA, lipids, and carbohydrates. These components play a crucial role in all stages of tumorigenesis and development. Moreover, they reflect the physiological and pathological status of parental tumor cells. Recently, tumor-derived exosomes have become popular biomarkers for non-invasive liquid biopsy and the diagnosis of numerous cancers. The interdisciplinary significance of exosomes research has also attracted growing enthusiasm. However, the intrinsic nature of tumor-derived exosomes requires advanced methods to detect and evaluate the complex biofluid. This review analyzes the relationship between exosomes and tumors. It also summarizes the exosomal biological origin, composition, and application of molecular markers in clinical cancer diagnosis. Remarkably, this paper constitutes a comprehensive summary of the innovative research on numerous detection strategies for tumor-derived exosomes with the intent of providing a theoretical basis and reference for early diagnosis and clinical treatment of cancer.

Microarray analysis of differentially expressed long non-coding RNAs in daidzein-treated lung cancer cells

Daidzein has been found to significantly inhibit the proliferation of lung cancer cells, while its potential molecular mechanisms remain unclear. To determine the molecular mechanism of daidzein on lung cancer cells, the Capital Bio Technology Human long non-coding (lnc) RNA Array v4, 4×180K chip was used to detect the gene expression profiles of 40,000 lncRNAs and 34,000 mRNAs in a human cancer cell line. Reverse transcription-quantitative (RT-q) PCR analysis was performed to detect the expression levels of target lncRNA and mRNAs in the H1299 cells treated with and without daidzein, using the lncRNA and mRNA gene chip. Bioinformatics analysis was performed to determine the differentially expressed genes from the results of the chip assays. There were 119 and 40 differentially expressed lncRNAs and mRNAs, respectively, that had a 2-fold change in expression level. A total of eight lncRNAs were upregulated in the H1299 lung cancer cells, while 111 lncRNAs were downregulated. Furthermore, five mRNAs were upregulated, and 35 mRNAs were downregulated. A total of six differentially expressed lncRNAs (ENST00000608897.1, ENST00000444196.1, ENST00000608741.1, XR_242163.1, ENST00000505196.1 and ENST00000498032.1) were randomly selected to validate the microarray data, which were consistent with the RT-qPCR analysis results. Differentially expressed mRNAs were enriched in important Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes pathways. Taken together, the results of the present study demonstrated that daidzein affected the expression level of lncRNAs in lung cancer cells, suggesting that daidzein may have potential effects on lung cancer cells.

Emerging Role of Extracellular Vesicles in Biomarking the Gastrointestinal Diseases

INTRODUCTION

Extracellular vesicles (EVs) play an important role in cell-cell communication and regulation of various cellular functions under physiological and pathophysiological conditions through transferring their cargo to recipient cells. Molecular constituents of EVs are a fingerprinting profile of secreting cells which can be used as promising prognostic, diagnostic, and drug-response biomarkers in clinical settings.

AREAS COVERED

The present study provides a brief introduction about the biology of EVs and reviews methodologies used for EV isolation and characterization as well as high-throughput strategies to analyze EV contents. Furthermore, this review highlights the importance and unique role of EVs in the development and progression of gastrointestinal (GI) diseases, especially GI cancers, and then discusses their potential use, particularly those isolated from body fluids, in diagnosis and prognosis of GI diseases.

EXPERT OPINION

In-depth analysis of EV content can lead to the identification of new potential biomarkers for early diagnosis and prognosis prediction of GI diseases. The use of a more targeted approach by establishing more reproducible and standardized methods to decrease variations and obtain desired EV population as well as revisiting large pools of identified biomarkers and their evaluation in larger patient cohorts can result in the introduction of more reliable biomarkers in clinic.

Enhanced LINC01061 Levels as a Serum Biomarker in Gastric Cancer and Promotion of Malignant Transformation

BACKGROUND

The genomic copy number of LINC01061 is amplified in papillary thyroid cancer. However, its role in gastric cancer is not clear.

MATERIALS AND METHODS

Tissues and serum of GC patients were collected to detect the expression of LINC01061 by quantitative real-time polymerase chain reaction (qRT-PCR). ShRNA were applied to knock down the expression of LINC01061. Growth curves and colony formation experiments were applied to evaluate cell growth. Cell migration was assessed by transwell migration experiments. Cell cycle and apoptosis were analyzed by flow cytometry. Epithelial-mesenchymal transition (EMT) was examined by qRT-PCR and Western blot.

RESULTS

The expression of LINC01061 was upregulated in tissues and serum of GC patients and it was associated with the clinicopathological features and survival time. Functional study indicated that cell growth and migration were suppressed after LINC01061 knockdown. Cell cycle arrest and increased apoptosis occurred when LINC01061 expression was inhibited. EMT was also impaired combined with a decrease in β-catenin expression after LINC01061 knockdown.

CONCLUSIONS

Our data indicate that LINC01061 is a novel biomarker for diagnosis and prognosis of GC. LINC01061 promoted progression of GC through cell cycle regulation and EMT.

Circulating long noncoding RNAs as potential biomarkers for stomach cancer: a systematic review and meta-analysis

Background

Recent researches have suggested that long noncoding RNA (lncRNA) is involved in the tumorigenesis and development of stomach cancer (SC). This meta-analysis aimed to identify the diagnostic performance of circulating lncRNAs in SC.

Methods

All relevant studies were systematically searched through PubMed, Web of Science, Cochrane Library, and EMBASE databases. The diagnostic values of lncRNAs were mainly assessed by pooled sensitivity, specificity, and summary receiver operating characteristic area under the curve (SROC AUC). Meta-DiSc 1.4, Review Manager 5.3, and STATA 12.0 were used for statistical analysis. The protocol for this systematic review was registered on INPLASY (INPLASY202120079) and is available in full on the inplasy.com (10.37766/inplasy2021.2.0079).

Results

A total of 42 eligible studies were included in this meta-analysis. The pooled sensitivity, specificity, and SROC AUC were 0.78 (95%CI 0.75–0.81), 0.75 (95%CI 0.71–0.78), and 0.83 (95%CI 0.80–0.86), respectively, suggesting that the lncRNAs test had a high accuracy for the diagnosis of SC. Obvious heterogeneity might come from the type of lncRNA through subgroup and meta-regression analysis. Fagan diagram shows the clinical value of lncRNAs test in SC.

Conclusions

Abnormal expression of circulating lncRNAs exhibits a high efficacy for diagnosing SC, which is promising in clinical application.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02194-6.

Highly Specialized Ubiquitin-Like Modifications: Shedding Light into the UFM1 Enigma

Post-translational modification with Ubiquitin-like proteins represents a complex signaling language regulating virtually every cellular process. Among these post-translational modifiers is Ubiquitin-fold modifier (UFM1), which is covalently attached to its substrates through the orchestrated action of a dedicated enzymatic cascade. Originally identified to be involved embryonic development, its biological function remains enigmatic. Recent research reveals that UFM1 regulates a variety of cellular events ranging from DNA repair to autophagy and ER stress response implicating its involvement in a variety of diseases. Given the contribution of UFM1 to numerous pathologies, the enzymes of the UFM1 cascade represent attractive targets for pharmacological inhibition. Here we discuss the current understanding of this cryptic post-translational modification especially its contribution to disease as well as expand on the unmet needs of developing chemical and biochemical tools to dissect its role.

Non-coding RNAs in gastric cancer

Non-coding RNAs (ncRNAs) are functional RNA molecules that play crucial regulatory roles in many fundamental biological processes. The dysregulation of ncRNAs is significantly associated with the progression of human cancers, including gastric cancer. In this review, we have summarized the oncogenic or tumor-suppressive roles and the regulatory mechanisms of lncRNAs, miRNAs, circRNAs and piRNAs, and have discussed their potential as biomarkers or therapeutic targets in gastric cancer.

Long non-coding RNAs in gastric cancer: New emerging biological functions and therapeutic implications

Gastric cancer (GC) is currently the fourth most common malignancy and the third leading cause of cancer-related deaths worldwide. Long non-coding RNAs (lncRNAs), transcriptional products with more than 200 nucleotides, are not as well-characterized as protein-coding RNAs. Accumulating evidence has recently revealed that maladjustments of diverse lncRNAs may play key roles in multiple genetic and epigenetic phenomena in GC, affecting all aspects of cellular homeostasis, such as proliferation, migration, and stemness. However, the full extent of their functionality remains to be clarified. Considering the lack of viable biomarkers and therapeutic targets, future research should be focused on unravelling the intricate relationships between lncRNAs and GC that can be translated from bench to clinic. Here, we summarized the state-of-the-art advances in lncRNAs and their biological functions in GC, and we further discuss their potential diagnostic and therapeutic roles. We aim to shed light on the interrelationships between lncRNAs and GC with respect to their potential therapeutic applications. With better understanding of these relationships, the biological functions of lncRNAs in GC development will be exploitable, and promising new strategies developed for the prevention and treatment of GC.

TMPO-AS1 promotes cell proliferation of thyroid cancer via sponging miR-498 to modulate TMPO

Background

Thyroid cancer (TC) is the most frequent endocrine malignancy. Long noncoding RNAs (lncRNAs) have been confirmed to act as significant roles in tumor development. The role of lncRNA TMPO-AS1 in TC is still unclear, so it remains to be explored. The aim of the research is to investigate the role and regulatory mechanism of TMPO-AS1 in TC.

Methods

TMPO-AS1 and TMPO expression in TC tumors and cells was detected by TCGA database and QRT-PCR assay respectively. CCK-8, EDU, TUNEL and western blot assays were conducted to identify the biological functions of TMPO-AS1 in TC. Luciferase reporter and RNA pull down assays were conducted to measure the interaction among TMPO-AS1, TMPO and miR-498.

Results

TMPO-AS1 was overexpressed in TC tissues and cell lines. Knockdown of TMPO-AS1 suppressed cell growth and accelerated cell apoptosis in TC. Furthermore, downregulation of TMPO-AS1 suppressed TMPO expression in TC. The data suggested that TMPO expression was upregulated in TC tissues and cell lines and was positively correlated with TMPO-AS1 expression in TC. Furthermore, the expression of miR-498 presented low expression in TC cells. And miR-498 expression was negatively regulated by TMPO-AS1, meanwhile, TMPO expression was negatively regulated by miR-498 in TC cells. Besides, it was confirmed that TMPO-AS1 could bind with miR-498 and TMPO in TC cells. In addition, it was validated that TMPO-AS1 elevated the levels of TMPO via sponging miR-498 in TC cells.

Conclusions

TMPO-AS1 promotes cell proliferation in TC via sponging miR-498 to modulate TMPO.

Long non-coding RNAs as potential markers for occurrence, progression, and prognosis of gastric cancer

In recent years, more and more attention has been paid to the relationship between long non-coding RNAs (lncRNAs) and tumor. Abnormal expression of lncRNAs plays an oncogenic or tumor-suppressing role in gastric cancer (GC) by participating in the biological behaviors of GC cells, such as proliferation, invasion, and migration. By summarizing the relevant literature, this paper discusses the research status, detection technology, and mechanism of action of lncRNAs in GC, as well as their potential as markers for occurrence, progression, prognosis, and drug resistance of GC. It is expected that lncRNAs can play an important role in early detection, early treatment, and effective improvement of chemotherapy resistance of GC to achieve personalized precise treatment of this malignancy.

The potential of liquid biopsies in gastrointestinal cancer

BACKGROUND

Liquid biopsy is a novel approach for cancer diagnosis, the value of which in human gastrointestinal (GI) cancer has been confirmed by the previous studies. This article summarized the recent advances in liquid biopsy with a focus on novel technologies and the use of it in the screening, monitoring, and treatment of human GI cancer.

CONTENT

The concept of liquid biopsy was first used to define the detection of circulating tumor cells (CTCs) in cancer patients, and has been expanded to other biomarkers in blood and body fluids, such as circulating tumor DNA (ctDNA), extracellular vesicles (EVs) and circulating tumor RNA. If analyzed with proper and advanced techniques like next generation sequencing (NGS) or proteomics, liquid biopsies can open an enormous array of potential biomarkers. The amount changes of target biomarkers and the mutation of genetic materials provide quantitative and qualitative information, which can be utilized clinically for cancer diagnosis and disease monitoring.

SUMMARY

As a highly efficient, minimally invasive, and cost-effective approach to diagnose and evaluate prognosis of GI cancer, liquid biopsy has lots of advantages over traditional biopsy and is promising in future clinical utility. If the challenges are overcome in the near future, liquid biopsy will become a widely available and dependable option.

Advances in the role of exosomal non-coding RNA in the development, diagnosis, and treatment of gastric cancer (Review)

Exosomes are small vesicles secreted by a variety of cells that contain vrious biological macromolecules, including RNA, non-coding RNA and protein. An increasing number of studies have demonstrated that exosomes and particularly the non-coding RNAs they contain, serve important roles in many cellular processes, including the transmission of information. It is well established that the occurrence and development of gastric cancer, one of the four most common malignant tumors worldwide, involves the transmission of information. Based on the urgent need for the elucidation of the mechanism involved in this process, as well as advances in the diagnosis and treatment of gastric cancer, numerous reports have assessed the association between non-coding RNAs in exosomes and gastric cancer. The purpose of the present review was to summarize recent evidence on certain non-coding RNAs associated with the development, diagnosis and treatment of gastric cancer.

Ran GTPase: A Key Player in Tumor Progression and Metastasis

Ran (Ras-related nuclear protein) GTPase is a member of the Ras superfamily. Like all the GTPases, Ran cycles between an active (GTP-bound) and inactive (GDP-bound) state. However, Ran lacks the CAAX motif at its C-terminus, a feature of other small GTPases that ensures a plasma membrane localization, and largely traffics between the nucleus and the cytoplasm. Ran regulates nucleo-cytoplasmic transport of molecules through the nuclear pore complex and controls cell cycle progression through the regulation of microtubule polymerization and mitotic spindle formation. The disruption of Ran expression has been linked to cancer at different levels - from cancer initiation to metastasis. In the present review, we discuss the contribution of Ran in the acquisition of three hallmarks of cancer, namely, proliferative signaling, resistance to apoptosis, and invasion/metastasis, and highlight its prognostic value in cancer patients. In addition, we discuss the use of this GTPase as a therapeutic target in cancer.

Exosome-transmitted lncRNA UFC1 promotes non-small-cell lung cancer progression by EZH2-mediated epigenetic silencing of PTEN expression

Long non-coding RNAs (LncRNAs) have been suggested as important regulators of cancer development and progression in non-small cell lung cancer (NSCLC). Nevertheless, the biological roles and clinical significance of lncRNA UFC1 in NSCLC remain unclear. We detected the expression of UFC1 in tumor tissues, serum, and serum exosomes of NSCLC patients by qRT-PCR. Gene overexpression or silencing were used to examine the biological roles of UFC1 in NSCLC. RNA immunoprecipitation and ChIP assays were performed to evaluate the interaction between UFC1 and enhancer of zeste homolog 2 (EZH2) and the binding of EZH2 to PTEN gene promoter. Rescue study was used to access the importance of PTEN regulation by UFC1 in NSCLC progression. UFC1 expression was upregulated in tumor tissues, serum, and serum exosomes of NSCLC patients and high level of UFC1 was associated with tumor infiltration. UFC1 knockdown inhibited NSCLC cell proliferation, migration and invasion while promoted cell cycle arrest and apoptosis. UFC1 overexpression led to the opposite effects. Mechanistically, UFC1 bound to EZH2 and mediated its accumulation at the promoter region of PTEN gene, resulting in the trimethylation of H3K27 and the inhibition of PTEN expression. UFC1 knockdown inhibited NSCLC growth in mouse xenograft tumor models while the simultaneous depletion of PTEN reversed this effect. NSCLC cells derived exosomes could promote NSCLC cell proliferation, migration and invasion through the transfer of UFC1. Moreover, Exosome-transmitted UFC1 promotes NSCLC progression by inhibiting PTEN expression via EZH2-mediated epigenetic silencing. Exosome-mediated transmit of UFC1 may represent a new mechanism for NSCLC progression and provide a potential marker for NSCLC diagnosis.

Long Non-Coding RNA Taurine Upregulated Gene 1 (TUG1) Downregulation Constrains Cell Proliferation and Invasion through Regulating Cell Division Cycle 42 (CDC42) Expression Via MiR-498 in Esophageal Squamous Cell Carcinoma Cells

Background

Esophageal squamous cell carcinoma (ESCC) is a malignant tumor of the gastrointestinal tract. Taurine upregulated gene 1 (TUG1), a long non-coding (lnc) RNA, also known as LIN00080 or TI-227H, was connected with the tumorigenesis of various diseases. Hence, we plumed the role and molecular mechanism of TUG1 in the progression of ESCC.

Material/Methods

Expression patterns of TUG1, microRNA-498 (miR-498), and cell division cycle 42 (CDC42) mRNA were assessed using quantitative real time polymerase chain reaction (qRT-PCR). The expression level of CDC42 protein was evaluated via western blot analysis. Cell proliferation and invasion were determined with Cell Counting Kit-8 (CCK-8) assay or Transwell assay. The relationship between miR-498 and TUG1 or CDC42 was predicted by online bioinformatics database LncBase Predicted v.2 or microT-CDS and confirmed through dual-luciferase reporter system or RNA immunoprecipitation assay (RIP).

Results

TUG1 and CDC42 were upregulated while miR-498 was strikingly decreased in ESCC tissues and cells (P<0.0001). Besides, TUG1 suppression blocked the proliferation and invasion of ESCC cells (P<0.001). Importantly, TUG1 decrease restrained CDC42 expression via binding to miR-498 in ESCC cells. Also, the suppressive impacts of TUG1 silencing on the proliferation and invasion of ESCC cells were mitigated by miR-498 reduction. Meanwhile, the repression of proliferation and invasion induced by miR-498 elevation was weakened by CDC42 overexpression.

Conclusions

Inhibition of TUG1 hampered cell proliferation and invasion by downregulating CDC42 via upregulating miR-498 in ESCC cells. Thus, TUG1 might be an underlying therapeutic target for ESCC.

LncRNA CTC-497E21.4 promotes the progression of gastric cancer via modulating miR-22/NET1 axis through RhoA signaling pathway

BACKGROUND

Long non-coding RNAs (lncRNAs) have emerged as important roles in gastric cancer (GC). However, the role of the dysregulated lncRNAs in GC remained large unknown. We investigated the clinical significance, biological function and mechanism of CTC-497E21.4 in GC.

METHODS

Firstly, RTFQ-PCR was used to detect the expression of CTC-497E21.4 in GC. Furthermore, knockdown of CTC-497E21.4 was conducted to assess the effect of CTC-497E21.4 in vitro and vivo. Subcellular localization of CTC-497E21.4 was determined by nuclear plasmolysis PCR and FISH. We also predicted CTC-497E21.4 binding miRNAs and downstream target genes and evaluated its regulation of miR-22 by acting as a ceRNA.

RESULT

CTC-497E21.4 was upregulated in GC tissues and GC cell lines (P < 0.05), and the expression was associated with depth of invasion, lymph node metastasis, and neurological invasion. Besides, knockdown of CTC-497E21.4 inhibited cell proliferation, invasion and promoted cell cycle arrest in vitro and inhibited tumorigenesis in vivo. Mechanistic investigations indicated that CTC-497E21.4 acted as a ceRNA for miR-22 and regulated NET1 expression. CTC-497E21.4/miR-22-3p/NET1 participated in the RhoA signaling pathway in the GC progression.

CONCLUSION

CTC-497E21.4 competed with miR-22 to regulate the expression of NET1 and regulated the malignant progression of GC through RhoA signaling pathway.

The regulatory roles and potential prognosis implications of long non-coding RNAs in gastric cancer

Accumulating dysregulated lncRNAs have been demonstrated to execute vital functions in the pathogenesis and progress of gastric cancer (GC) through versatile molecular mechanisms. In this review, we classify the mechanisms of dysregulated lncRNAs in GC into several governing types according to their roles at molecular level. For each regulatory role, we illustrate several instructive examples and introduce significant effects of lncRNAs on cellular biological properties of GC. Besides, we summarize a group of lncRNA-signatures that are potential biomarkers in the prediction of prognosis for GC patients.

Serum lncRNA-UFC1 as a potential biomarker for diagnosis and prognosis of pancreatic cancer

Early diagnosis is important to improve the prognosis of pancreatic cancer (PC). Identifying potential biomarkers is essential for the monitoring and treatment of PC. The long noncoding RNA (lncRNA) UFC1 has been identified as an oncogenic factor in many cancers. However, the expression of UFC1 and its potential role in diagnosis and prognosis of PC remain largely unknown. The present study aimed to investigate the role of serum UFC1 in diagnosis and prognosis. The results indicated that serum UFC1 expression was relatively higher in PC patients than that in healthy volunteers. ROC curve analysis revealed that the serum UFC1 levels could distinguish PC patients from healthy controls, with an AUC value of 0.810. In addition, the serum UFC1 expression level was associated with lymph nodes metastasis, distant metastasis, and clinical stage. Kaplan-Meier analysis indicated that patients with high UFC1 expression exhibited shorter progression-free survival (PFS) and overall survival (OS) than those with low UFC1 expression. Multivariate analysis demonstrated that clinical stage and UFC1 expression level were significant, independent prognostic factors in PC patients. Our data demonstrate that serum UFC1 might serve as a potential biomarker for diagnosis and prognosis of PC.

Long Non-Coding RNA (LncRNA) UFC1/miR-34a Contributes to Proliferation and Migration in Breast Cancer

Background

At present, a number of long non-coding RNAs (lncRNAs) have been realized as the critical regulators of breast cancers. Current evidence indicates that dysregulation of UFC1 contributes to the tumorigenesis and progression of various types of human cancer. However, the roles of UFC1 in breast cancer are still unclear.

Material/Methods

Firstly, we measured the expression of UFC1 in breast cancer tissues and cells lines compared with corresponding controls. Then, cell functional assays were performed to determine the roles of UFC1 in breast cancer progression in vitro. Moreover, the correlation between UFC1 and miR-34a was determined by luciferase reporter assays. Further, the role of miR-34a in regulating biological function of breast cancer and its downstream target CXCL10 was applied by a series of functional assays.

Results

In present study, we found that UFC1 was highly expressed in breast tissue and cells lines compared with normal tissues and cell lines. Silenced UFC1 suppressed multiple biological activities of breast cancer cells, which also functioned as a miR-34a sponge in breast cancer. Furthermore, over-expressing miR-34a could prominently suppress cell growth, invasion, migration and inducing apoptosis in breast cancer cells. In addition, we verified that miR-34a was a target of CXCL10 by bioinformatics analysis and luciferase reporter assay.

Conclusions

LncRNA UFC1 regulated biological activity of breast cancer via miR-34a/CXCL10 axis, providing a novel diagnosis biomarker and potential therapeutic target for breast cancer.

Epigenetic regulation of IncRNA KCNKI5-ASI in gastric cancer

Background

Long noncoding RNAs (lncRNAs) play an important role in gastric cancer. In this study, we aimed to uncover the epigenetic regulatory mechanism of lncRNA KCNK15-AS1 in gastric cancer progression.

Patients and methods

Forty patients were included in the study. The expression of KCNK15-AS1 was detected by real-time PCR (RT-PCR), the promoter of KCNK15-AS1 was detected by methylation-specific PCR, and the luciferase assay was performed to detect the relationship between KCNK15-AS1 and miR-21. The relationship of the proteins was explored by an RNA pull-down assay and RNA immunoprecipitation. Chromatin immunoprecipitation was performed to detect the relationship between the promoter and the protein.

Results

The expression of KCNK15-AS1 was lower in the tumor tissue compared to the normal tissue. KCNK15-AS1 interacted with miR-21. Both the overexpression of KCNK15-AS1 and the knockdown of the expression of miR-21 inhibited proliferation and promoted apoptosis and decreased the level of MMP-9, bcl-2, and MMP-2 but increased the level of Bax. In addition, the methylation of KCNK15-AS1 was detected in the tumor tissue but was not detected in the normal tissue. Treatment with 5-azacytidine and chidamide decreased the level of DNMT1 and HDAC1 and increased the level of KCNK15-AS1. The RNA pull-down and RNA immunoprecipitation results showed that KCNK15-AS1 interacted with DNMT1 and HDAC1. The ChIP-seq result showed that the promoter of MAPK interacted with DNMT1, and the promoter of AKT and STAT5 interacted with HDAC1.

Conclusion

In this study, we identified two regulatory axes, namely KCNK15-AS1-DNMT1-MAPK and KCNK15-AS1-HDAC1-AKT, which were associated with gastric cancer progression. Chidamide and 5-azacytidine might provide new modes for treating gastric cancer.

miR-374a-5p: A New Target for Diagnosis and Drug Resistance Therapy in Gastric Cancer

Chemoresistance is one of the causes associated with poor prognosis in gastric cancer. MicroRNAs (miRNAs) are important regulators of chemoresistance. Exosome-mediated delivery of anti-cancer molecules and drugs have emerged as a new approach for cancer therapy. We first examined the expression of miR-374a-5p in gastric cancer serum by qRT-PCR and explored the clinicopathological parameters. We then performed in vitro cell and molecular studies, including CCK-8 assay, flow cytometry, qRT-PCR, and western blot, to determine the roles of miR-374a-5p in gastric cancer chemoresistance and identified its downstream target by luciferase reporter assay. We also used in vivo animal studies to evaluate the therapeutic efficacy of miR-374a-5p inhibitor and exosome-mediated delivery of miR-374a-5p inhibitor in gastric cancer. miR-374a-5p expression level was elevated in gastric cancer serum, and its upregulation predicted poor prognosis. miR-374a-5p overexpression promoted while miR-374a-5p knockdown inhibited gastric cancer chemoresistance in vitro and in vivo. miR-374a-5p bound to Neurod1 to antagonize its effect on chemoresistance. Exosome-mediated delivery of miR-374a-5p inhibitor could increase Neurod1 expression, promote cell apoptosis, and suppress chemoresistance. miR-374a-5p had a promoting role in gastric cancer chemoresistance, which would provide a novel biomarker for gastric cancer diagnosis and prognosis and offer a potential target for gastric cancer drug resistance therapy.

Incorporating molecular biomarkers into clinical practice for gastric cancer

Introduction: Gastric cancer is one of the most common causes of cancer-related mortality worldwide. To improve clinical outcomes, it is critical to develop appropriate approaches to diagnosis and treatment. Biomarkers have numerous potential clinical applications, including screening, assessing risk, determining prognosis, monitoring recurrence, and predicting response to treatment. Furthermore, biomarkers may contribute to the development of effective therapies. Areas covered: Here we review recent progress in exploiting GC-specific biomarkers such as protein-coding genes, microRNAs, long noncoding RNAs, and methylated gene promoters. Expert opinion: The development of biomarkers for diagnosing and monitoring gastric cancer and for individualizing therapeutic targets shows great promise for improving gastric cancer management.

LncRNA GClnc1 promotes proliferation and invasion of bladder cancer through activation of MYC

Various studies demonstrate that long noncoding RNAs (lncRNAs) act as oncogenes or tumor suppressors in cancer. However, the function of lncRNAs in bladder cancer still remains largely unknown. In this study, we identified an lncRNA, gastric cancer-associated lncRNA1 (GClnc1), which was in high abundance in bladder cancer tissues and its expression was related to poor survival rates in patients with bladder cancer. In vitro and in vivo assays showed that GClnc1 significantly promoted cell proliferation, metastasis, and invasiveness in bladder cancer. Mechanistically, we first found that GClnc1 bound to LIN28B and promoted the expression of myelocytomatosis proto-oncogene (MYC) through the LIN28B/let-7a/MYC pathway. In short, GClnc1 is clinically, functionally, and mechanistically oncogenic in bladder cancer. GClnc1 may be a potential target for treating patients with bladder cancer.-Zhuang, C., Ma, Q., Zhuang, C., Ye, J., Zhang, F., Gui, Y. LncRNA GClnc1 promotes proliferation and invasion of bladder cancer through activation of MYC.

LncRNA TTN-AS1 drives invasion and migration of lung adenocarcinoma cells via modulation of miR-4677-3p/ZEB1 axis

Lung adenocarcinoma is the most prevalent type of lung cancer with a high incidence and mortality worldwide. Metastasis is the major cause of high death rate in lung cancer and the potential mechanism of lung adenocarcinoma metastasis remains indistinct. Emerging investigations have demonstrated that long noncoding RNA is a kind of non-protein coding RNA and plays a critical role in cancer progression and metastasis. TTN antisense RNA 1 (TTN-AS1) has been reported to promote cell growth and metastasis in cancer. However, the function of TTN-AS1 in lung adenocarcinoma is still to be illustrated. In this study, we observed that TTN-AS1 was upregulated in tissues and cells of lung adenocarcinoma and associated with poor overall survival. TTN-AS1 promoted cell proliferation, migration, invasion, and epithelial-mesenchymal transition in lung cancer. TTN-AS1 directly bound with miR-4677-3p and negatively regulated miR-4677-3p. MiR-4677-3p rescued the inhibitive impacts of TTN-AS1 knockdown on lung adenocarcinoma. Furthermore, zinc finger E-box binding homeobox 1 (ZEB1) was the target of miR-4677-3p, and TTN-AS1 modulated ZEB1 by competing for miR-4677-3p. TTN-AS1 drove the invasion and migration of lung adenocarcinoma cells by targeting the miR-4677-3p/ZEB1 axis. To sum up, our study offers insights into the mechanism of TTN-AS1 in lung adenocarcinoma metastasis and targeting the TTN-AS1/miR-4677-3p/ZEB1 axis may be the potential innovate therapeutic strategy for the patients with lung adenocarcinoma.

Exosomes: from carcinogenesis and metastasis to diagnosis and treatment of gastric cancer

Exosomes represent an important group of extracellular vesicles with a defined size between 40 and 150 nm and cup-shaped construction which have a pivotal role in elimination of intracellular debris and intercellular signaling networks. A line of evidence revealed the impact of different types of exosomes in initiation, progression, and metastasis of gastric cancer (GC). These bioactive vesicles mediate tumor and stromal communication network through modulation of cell signaling for carcinogenesis and pre-metastatic niche formation in distant organs. Exosomes contain various cargos including DNAs (mitochondrial and genomic), proteins, transposable elements, and RNAs (coding and noncoding) with different compositions related to functional status of origin cells. In this review, we summarize the main roles of key exosomal cargos in induction of exosome-mediated signaling in cancer cells. Body fluids are employed frequently as the source of exosomes released by tumor cells with a potential role in early diagnosis of GC and chemoresistance. These vesicles as non-toxic and non-immunogenic carriers are also found to be applied for novel drug delivery systems.

MiR-128-3p increases sensitivity of hepatoma cells to oxaliplatin by targeting Lin28B

AIM

To investigate the effect of miR-128-3p on the sensitivity of hepatocellular carcinoma (HCC) cells to oxaliplatin, and explore the underlying mechanism.

METHODS

qRT-PCR was used to detect the expression of miR-128-3p and Lin28B in human liver cells (HL-7702) and human HCC cells (BEL-7402 and Hep-3B). BEL-7402 and Hep-3B cells as well as oxaliplatin resistant BEL-7402 and Hep-3B cells in logarithmic growth phase were randomly divided into a miR-128-3p mimic group (transfected with miR-128-3p mimics), a miR-NC group (untransfected cells), a Lin28B-3ʹ UTR WT group (psiCHECK2-Lin28B-3ʹUTR WT and miR-128-3p co-transfection), a Lin28B-3ʹ-UTR MUT (psiCHECK2-Lin28B-3ʹ UTR MUT and miR-NC co-transfection), a miR-128-3p + Lin28B group (miR-128-3p and Lin28B co-transfection), a si-Lin28B group (transfected with si-Lin28B) and a si-NC (transfected with silencing control). All cells were transfected via liposomes. The survival rate and viability of each group were detected by MTT assay, and the protein expression was detected by Western blot.

RESULTS

Compared with human hepatocytes, the expression of miR-128-3p in HCC cells (BEL-7402 and Hep-3B) was significantly decreased, and the expression of Lin28B was significantly increased. Overexpression of miR-128-3p or silencing Lin28B increased the sensitivity of HCC cells to oxaliplatin. Lin28B is a target of miR-128-3p, and overexpression of Lin28B could reverse the effect of miR-128-3p in increasing the sensitivity of HCC cells to oxaliplatin.

CONCLUSION

MiR-128-3p can increase the sensitivity of HCC cells to oxaliplatin possibly via a mechanism related to targeting Lin28B, suggesting that miR-128-3p could be used as a potential target for treatment of oxaliplatin resistance.