LncRNA H19/miR-29b-3p/PGRN Axis Promoted Epithelial-Mesenchymal Transition of Colorectal Cancer Cells by Acting on Wnt Signaling

Biomarkers (mRNAs and Non-Coding RNAs) for the Diagnosis and Prognosis of Colorectal Cancer - From the Body Fluid to Tissue Level

In recent years, the diagnosis and treatment of colorectal cancer (CRC) have been continuously improved, but the mortality rate continues to be high, especially in advanced patients. CRC patients usually have no obvious symptoms in the early stage and are already in the advanced stage when they are diagnosed. The 5-year survival rate is only 10%. The blood markers currently used to screen for CRC, such as carcinoembryonic antigen and carbohydrate antigen 19-9, have low sensitivity and specificity, whereas other methods are invasive or too expensive. As a result, recent research has shifted to the development of minimally invasive or noninvasive biomarkers in the form of body fluid biopsies. Non-coding RNA molecules are composed of microRNAs, long non-coding RNAs, small nucleolar RNAs, and circular RNAs, which have important roles in the occurrence and development of diseases and can be utilized for the early diagnosis and prognosis of tumors. In this review, we focus on the latest findings of mRNA-ncRNA as biomarkers for the diagnosis and prognosis of CRC, from fluid to tissue level.

LncRNA GATA3‑AS1‑miR‑30b‑5p‑Tex10 axis modulates tumorigenesis in pancreatic cancer

Long noncoding RNAs (lncRNAs) have been widely recognized to play an important role in a variety of diseases. Abnormal regulation of lncRNA GATA3-antisense RNA 1 (AS1) occurs in several cancers, but whether it is involved in the progression of pancreatic cancer (PC) remains unknown. The present study aimed to investigate the biological effects of GATA3-AS1 in PC and to explore the underlying molecular mechanisms. Upregulation of GATA3-AS1 was revealed in PC tissues and cell lines. Knockdown of GATA3-AS1 in PANC-1 or AsPC-1 cells markedly reduced cell viability, cell proliferation, and cell invasion abilities, while cell apoptosis was increased. In addition, GATA3-AS1 knockdown suppressed the stemness of PANC-1 and AsPC-1 cells by decreasing the spheroid formation ability. A tumor xenograft in vivo assay demonstrated that GATA3-AS1 knockdown inhibited tumorigenicity of AsPC-1 cells. Furthermore, the microRNA (miR)-30b-5p downregulation and GATA3-AS1 upregulation were revealed in PC tissues and cell lines. Negative correlations were present between GATA3-AS1 and miR-30b-5p and between miR-30b-5p and testis-expressed protein 10 (Tex10) in the PC tissues, while GATA3-AS1 and Tex10 were positively correlated. GATA3-AS1 was then revealed to act as a competing endogenous RNA (ceRNA) for miR-30b-5p in regulating Tex10 expression. Moreover, the miR-30b-5p-Tex10 axis was confirmed to be involved in the regulation of biological effects of GATA3-AS1, including cell viability, cell proliferation, cell invasion, cell apoptosis, and cell stemness, as well as Wnt1/β-catenin signaling. Collectively, these data indicated that the GATA3-AS1-miR-30b-5p-Tex10 axis modulates tumorigenesis in PC, which may be associated with the Wnt/β-catenin signaling pathway.

Comprehensive analysis of ceRNA networks reveals prognostic lncRNAs related to immune infiltration in colorectal cancer

BACKGROUND

Competing endogenous RNA (ceRNA) represents a class of RNAs (e.g., long noncoding RNAs [lncRNAs]) with microRNA (miRNA) binding sites, which can competitively bind miRNA and inhibit its regulation of target genes. Increasing evidence has underscored the involvement of dysregulated ceRNA networks in the occurrence and progression of colorectal cancer (CRC). The purpose of this study was to construct a ceRNA network related to the prognosis of CRC and further explore the potential mechanisms that affect this prognosis.

METHODS

RNA-Seq and miRNA-Seq data from The Cancer Genome Atlas (TCGA) were used to identify differentially expressed lncRNAs (DElncRNAs), microRNAs (DEmiRNAs), and mRNAs (DEmRNAs), and a prognosis-related ceRNA network was constructed based on DElncRNA survival analysis. Subsequently, pathway enrichment, Pearson correlation, and Gene Set Enrichment Analysis (GSEA) were performed to determine the function of the genes in the ceRNA network. Gene Expression Profiling Interactive Analysis (GEPIA) and immunohistochemistry (IHC) were also used to validate differential gene expression. Finally, the correlation between lncRNA and immune cell infiltration in the tumor microenvironment was evaluated based on the CIBERSORT algorithm.

RESULTS

A prognostic ceRNA network was constructed with eleven key survival-related DElncRNAs (MIR4435-2HG, NKILA, AFAP1-AS1, ELFN1-AS1, AC005520.2, AC245884.8, AL354836.1, AL355987.4, AL591845.1, LINC02038, and AC104823.1), 54 DEmiRNAs, and 308 DEmRNAs. The MIR4435-2HG- and ELFN1-AS1-associated ceRNA subnetworks affected and regulated the expression of the COL5A2, LOX, OSBPL3, PLAU, VCAN, SRM, and E2F1 target genes and were found to be related to prognosis and tumor-infiltrating immune cell types.

CONCLUSIONS

MIR4435-2HG and ELFN1-AS1 are associated with prognosis and tumor-infiltrating immune cell types and could represent potential prognostic biomarkers or therapeutic targets in colorectal carcinoma.

Sulforaphane Inhibits the Expression of Long Noncoding RNA H19 and Its Target APOBEC3G and Thereby Pancreatic Cancer Progression

Pancreatic ductal adenocarcinoma (PDAC) is extremely malignant and the therapeutic options available usually have little impact on survival. Great hope is placed on new therapeutic targets, including long noncoding RNAs (lncRNAs), and on the development of new drugs, based on e.g., broccoli-derived sulforaphane, which meanwhile has shown promise in pilot studies in patients. We examined whether sulforaphane interferes with lncRNA signaling and analyzed five PDAC and two nonmalignant cell lines, patient tissues (n = 30), and online patient data (n = 350). RT-qPCR, Western blotting, MTT, colony formation, transwell and wound healing assays; gene array analysis; bioinformatics; in situ hybridization; immunohistochemistry and xenotransplantation were used. Sulforaphane regulated the expression of all of five examined lncRNAs, but basal expression, biological function and inhibition of H19 were of highest significance. H19 siRNA prevented colony formation, migration, invasion and Smad2 phosphorylation. We identified 103 common sulforaphane- and H19-related target genes and focused to the virus-induced tumor promoter APOBEC3G. APOBEC3G siRNA mimicked the previously observed H19 and sulforaphane effects. In vivo, sulforaphane- or H19 or APOBEC3G siRNAs led to significantly smaller tumor xenografts with reduced expression of Ki67, APOBEC3G and phospho-Smad2. Together, we identified APOBEC3G as H19 target, and both are inhibited by sulforaphane in prevention of PDAC progression.

LINC00963 affects the development of colorectal cancer via MiR-532-3p/HMGA2 axis

Background

LINC00963 is high-expressed in various carcinomas, but its expression and function in colorectal cancer (CRC) have not been explored. This study explored the role and mechanism of LINC00963 in CRC.

Methods

The expression of LINC00963 in CRC and its relationship with prognosis were examined by starBase and survival analysis. The effects of LINC00963, miR-532-3p and HMGA2 on the biological characteristics and EMT-related genes of CRC cells were studied by RT-qPCR, CCK-8, clone formation experiments, flow cytometry, scratch test, Transwell, and Western blot. Xenograft assay and immunohistochemistry were performed to verify the effect of LINC00963 on tumor growth. The correlation among LINC00963, miR-532-3p, and HMGA2 was analyzed by bioinformatics analysis, luciferase assay, and Pearson test.

Results

LINC00963 was high-expressed in CRC, and this was associated with poor prognosis of CRC. Silencing LINC00963 inhibited the activity, proliferation, migration, and invasion of CRC cells, MMP-3 and MMP-9 expressions, moreover, it also blocked cell cycle progression, and inhibited tumor growth and Ki67 expression. However, overexpression of LINC00963 showed the opposite effects to silencing LINC00963. LINC00963 targeted miR-532-3p to regulate HMGA2 expression. Down-regulation of miR-532-3p promoted cell proliferation, migration and invasion, and expressions of MMP-3 and MMP-9, and knockdown of HMGA2 reversed the effect of miR-532-3p inhibitor. Up-regulation of miR-532-3p inhibited the biological functions of CRC cells, and overexpression of HMGA2 reversed the miR-532-3p mimic effect.

Conclusion

LINC00963 affects the development of CRC through the miR-532-3p/HMGA2 axis.

Progranulin Regulates Inflammation and Tumor

Progranulin (PGRN) mediates cell cycle progression and cell motility as a pleiotropic growth factor and acts as a universal regulator of cell growth, migration and transformation, cell cycle, wound healing, tumorigenesis, and cytotoxic drug resistance as a secreted glycoprotein. PGRN overexpression can induce the secretion of many inflammatory cytokines, such as IL-8, -6,-10, TNF-α. At the same time, this protein can promote tumor proliferation and the occurrence and development of many related diseases such as gastric cancer, breast cancer, cervical cancer, colorectal cancer, renal injury, neurodegeneration, neuroinflammatory, human atherosclerotic plaque, hepatocarcinoma, acute kidney injury, amyotrophic lateral sclerosis, Alzheimer’s disease and Parkinson’s disease. In short, PGRN plays a very critical role in injury repair and tumorigenesis, it provides a new direction for succeeding research and serves as a target for clinical diagnosis and treatment, thus warranting further investigation. Here, we discuss the potential therapeutic utility and the effect of PGRN on the relationship between inflammation and cancer.

HDAC2 inhibits EMT-mediated cancer metastasis by downregulating the long noncoding RNA H19 in colorectal cancer

BACKGROUND

Emerging evidence suggests that epithelial mesenchymal transition (EMT) and epigenetic mechanisms promote metastasis. Histone deacetylases (HDACs) and noncoding RNAs (ncRNAs) are important epigenetic regulators. Here, we elucidated a novel role of histone deacetylase 2 (HDAC2) in regulating EMT and CRC metastasis via ncRNA.

METHODS

The expression of HDACs in CRC was analyzed using the public databases and matched primary and metastatic tissues, and CRC cells with different metastatic potentials (DLD1, HCT116, SW480 and SW620). Microarray analysis was used to identify differential genes in parental and HDAC2 knockout CRC cells. EMT and histone modifications were determined using western blot and immunofluorescence. Migration ability was assessed by transwell assay, and metastasis was assessed in vivo using a tail vain injection. Gene expression and regulation was assessed by RT-PCR, chromatin immunoprecipitation and reporter assays. Protein interaction was assessed by immunoprecipitation. Specific siRNAs targeting H19, SP1 and MMP14 were used to validate their role in HDAC2 loss induced EMT and metastasis.

RESULTS

Reduced HDAC2 expression was associated with poor prognosis in CRC patients and found in CRC metastasis. HDAC2 deletion or knockdown induced EMT and metastasis by upregulating the long noncoding RNA H19 (LncRNA H19). HDAC2 inhibited LncRNA H19 expression by histone H3K27 deacetylation in its promoter via binding with SP1. LncRNA H19 functioned as a miR-22-3P sponge to increase the expression of MMP14. HDAC2 loss strongly promoted CRC lung metastasis, which was suppressed LncRNA H19 knockdown.

CONCLUSION

Our study supports HDAC2 as a CRC metastasis suppressor through the inhibition of EMT and the expression of H19 and MMP14.

Silencing long non-coding RNA XIST suppresses drug resistance in acute myeloid leukemia through down-regulation of MYC by elevating microRNA-29a expression

Background

Long non-coding RNAs (lncRNAs) are biomarkers participating in multiple disease development including acute myeloid leukemia (AML). Here, we investigated molecular mechanism of X Inactive-Specific Transcript (XIST) in regulating cellular viability, apoptosis and drug resistance in AML.

Methods

XIST, miR-29a and myelocytomatosis oncogene (MYC) expression in AML bone marrow cells collected from 62 patients was evaluated by RT-qPCR and Western blot analysis. Besides, the relationship among XIST, miR-29a and MYC was analyzed by dual luciferase reporter assay, RIP, and RNA pull down assays. AML KG-1 cells were treated with anti-tumor drug Adriamycin. The role of XIST/miR-29a/MYC in cellular viability, apoptosis and drug resistance in AML was accessed via gain- and loss-of-function approaches. At last, we evaluated role of XIST/miR-29a/MYC on tumorigenesis in vivo.

Results

XIST and MYC were up-regulated, and miR-29a was down-regulated in AML bone marrow cells. Silencing XIST inhibited cellular activity and drug resistance but promoted cellular apoptosis of KG-1 cells by down-regulating MYC. XIST inhibited miR-29a expression to up-regulate MYC. Moreover, silencing XIST inhibited tumorigenesis of AML cells in vivo.

Conclusions

Overall, down-regulation of XIST decreased MYC expression through releasing the inhibition on miR-29a, thereby reducing drug resistance, inhibiting viability and promoting apoptosis of AML cells.

The SP1-Induced Long Noncoding RNA, LINC00339, Promotes Tumorigenesis in Colorectal Cancer via the miR-378a-3p/MED19 Axis

Introduction

Accumulating evidence has indicated that long noncoding RNAs (lncRNAs) are pivotal regulators involved in the pathogenesis of cancer; however, the molecular mechanism of LINC00339 in colorectal cancer (CRC) remains unclear.

Methods

The quantitative real-time polymerase chain reaction for the expression of LINC00339 and miR-378a-3p and Western blots for MED19 were performed. A dual-luciferase assay was used to investigate the interaction between LIN00339 and miR-378a-3p, as well as between miR-378a-3p and MED19. Cell proliferation was determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and 5-ethynyl-2ʹ-deoxyuridine (EdU) assay. The cell cycle was analyzed by propidium iodide staining followed by flow cytometry analysis. The wound-healing and transwell invasion assays were used to evaluate cell migration and invasion.

Results

The expression of LINC00339 was significantly upregulated in CRC cells and tissues, and high LINC00339 expression indicated an advanced tumor stage. Further experiments demonstrated that SP1 activated LINC00339 expression by binding to its promoter region. Luciferase activity and RNA pull-down assays demonstrated a direct interaction between LINC00339 and miR-378a-3p. miR-378a-3p expression was decreased in CRC samples and negatively correlated with LINC00339 expression in tumors. Gain- and loss-of-function assays indicated that LINC00339 contributed to cell proliferation, cell cycle progression, migration, and invasion, while miR-378a-3p reversed these effects. Furthermore, cotransfection of wild-type MED19 3ʹ-UTR reporters and miR-378a-3p significantly reduced luciferase activity. MED19 mRNA and protein expression was inhibited and enhanced by miR-378a-3p and LINC00339, respectively. MED19 overexpression reversed the effect of miR-378a-3p on cellular processes. Moreover, LINC00339 promoted tumor growth in vivo and induced epithelial–mesenchymal transition (EMT) and activated the Wnt/β-catenin signaling pathway in cells.

Conclusion

Our findings demonstrate the regulatory role of the SP1/LINC00339/miR-378a-3p/MED19 axis in CRC tumorigenesis and provide novel insight into the molecular mechanism underlying CRC.

MicroRNAs: Multifaceted Regulators of Colorectal Cancer Metastasis and Clinical Applications

Colorectal cancer (CRC) is the third-commonest malignant cancer, and its metastasis is the major reason for cancer-related death. The process of metastasis is highly coordinated and involves a complex cascade of multiple steps. In recent years, miRNAs, as highly conserved, endogenous, noncoding, single-stranded RNA, has been confirmed to be involved in the development of various cancers. Considering that miRNA is also involved in a series of biological behaviors, regulating CRC occurrence and development, we review and summarize the role of miRNAs and related signaling pathways in several CRC-metastasis stages, including invasion and migration, mobility, metabolism, epithelial-mesenchymal transition, tumor-microenvironment communication, angiogenesis, anoikis, premetastatic-niche formation, and cancer stemness. In addition, we review the application of miRNAs as diagnostic CRC markers and in clinical treatment resistance. This review can contribute to understanding of the mechanism of miRNAs in CRC progression and provide a theoretical basis for clinical CRC treatment.

Platelet lysate induces chondrogenic differentiation of umbilical cord-derived mesenchymal stem cells by regulating the lncRNA H19/miR-29b-3p/SOX9 axis

Platelet lysate (PL) has been shown to induce chondrogenic differentiation of human umbilical cord‐derived mesenchymal stem cells (hUCMSCs). However, the underlying mechanism is still not clear. The aim of this study was to investigate whether long noncoding RNA H19 is involved in this process. hUCMSCs were isolated, identified and cultured in 5% PL‐supplemented chondrogenic differentiation medium. Chondrogenic differentiation was assessed by Alcian blue staining. The expressions of H19, miR‐29b‐3p, SRY‐related high‐mobility‐group box 9 (SOX9), collagen II and aggrecan were determined by quantitative real‐time PCR and western blot. The interaction between miR‐29b‐3p and H19 or SOX9 was analyzed by luciferase reporter assay. During PL‐induced chondrogenic differentiation of hUCMSCs, expressions of H19 and SOX9 were increased, whereas miR‐29b‐3p expression was decreased. H19 overexpression promoted, whereas H19 silencing attenuated the PL‐induced chondrogenic differentiation of hUCMSCs. SOX9 was identified as a direct target of miR‐29b‐3p, and H19 was observed to act as a sponge of miR‐29b‐3p to up‐regulate SOX9 expression. The chondrogenic differentiation‐promoting effect of H19 overexpression was negated when miR‐29b‐3p expression was up‐regulated by Lenti‐miR‐29b‐3p infection. In conclusion, PL induced chondrogenic differentiation of hUCMSCs by regulating the H19/miR‐29b‐3p/SOX9 axis.

CircZFR serves as a prognostic marker to promote bladder cancer progression by regulating miR-377/ZEB2 signaling

Circular RNAs (circRNAs) have been identified as crucial regulators of gene expression in human cancer biology. CircZFR is a novel identified circRNA and its effect in bladder cancer remains unclearly. In the present study, we aimed to investigate the role of circZFR in the progression of bladder cancer. First, we demonstrated that the expression of circZFR was higher in bladder cancer tissues and cells compared with adjacent non-tumor tissues and normal bladder epithelial cells. And higher circZFR levels were positively correlated with bladder cancer patients’ pathological T stage, grade, lymphatic metastasis, recurrence, progression-free survival (PFS) and overall survival (OS). Functionally, knockdown of circZFR could significantly prohibit cell growth, migration and invasion, arrest cell cycle as well as promote apoptosis of bladder cancer cells in vitro study. Mechanistically, we observed that circZFR could directly bind to miR-377 as sponge to promote ZEB2 expression in bladder cancer cells. In addition, rescue assays demonstrated that restoration of ZEB2 significantly impaired the suppressive effects of circZFR silencing on bladder cancer cells growth, migration and invasion. Taken together, our results illuminated that circZFR could be a prognostic biomarker in bladder cancer and exerted oncogenic roles through regulating miR-377/ZEB2 axis in bladder cancer, which indicated that circZFR could be a potential therapeutic target for bladder cancer patients treatment.

An updated review of the H19 lncRNA in human cancer: molecular mechanism and diagnostic and therapeutic importance

Accumulating evidence has reported that H19 long non-coding RNA (lncRNA) expression level is deregulated in human cancer. It has been also demonstrated that de-regulated levels of H19 could affect cancer biology by various mechanisms including microRNA (miRNA) production (like miR-675), miRNA sponging and epigenetic modifications. Furthermore, lncRNA could act as a potential diagnosis and prognosis biomarkers and also a candidate therapeutic approach for different human cancers. In this narrative review, we shed light on the molecular mechanism of H19 in cancer development and pathogenesis. Moreover, we discussed the expression pattern and diagnostic and therapeutic importance of H19 as a potential biomarker in a range of human malignancies from breast to osteosarcoma cancer.

Long non-coding RNA (lncRNA) and epithelial-mesenchymal transition (EMT) in colorectal cancer: a systematic review

BACKGROUND

Colorectal cancer (CRC) is a leading cause of cancer-related death. Epithelial-mesenchymal transition (EMT) is a major process in tumor metastasis development. This systematic review aims to describe the role of long non-coding RNA (lncRNA) in EMT in CRC.

METHODS

The electronic databases, PubMed, Cochrane, and EMBASE, were searched from January1990 to June 2019 to identify studies examining lncRNA and their role in mediating EMT in CRC. Studies examining clinical specimens and/or in vitro experiments were included.

RESULTS

In 61 identified studies, 54 lncRNAs were increased in CRC compared to normal colorectal epithelium. Increased lncRNA expression was frequently associated with worse survival. Many lncRNAs mediate their effect through competitive endogenous RNA or transcription factor regulation. The ZEB1, 2/E-cadherin, Wnt/β-catenin signaling, and chromatin remodeling pathways are discussed in particular.

CONCLUSIONS

lncRNAs are major regulators of EMT and predictor adverse outcome in CRC patients. Future research must focus on delineating lncRNA function prior to potential clinical use.

Integration analysis of long non-coding RNA (lncRNA) role in tumorigenesis of colon adenocarcinoma

Background

Colon adenocarcinoma (COAD) is one of the most common gastrointestinal cancers globally. Molecular aberrations of tumor suppressors and/or oncogenes are the main contributors to tumorigenesis. However, the exact underlying mechanisms of COAD pathogenesis are clearly not known yet. In this regard, there is an urgent need to indicate promising potential diagnostic and prognostic biomarkers in COAD patients.

Methods

In the current study, level 3 RNA-Seq and miR-Seq data and corresponding clinical data of colon adenocarcinoma (COAD) were retrieved from the TCGA database. The “limma” package in R software was utilized to indicate the differentially expressed genes. For in silico functional analysis, GO and KEGG signaling pathways were conducted. PPI network was constructed based on the STRING online database by Cytoscape 3.7.2. A ceRNA network was also constructed by “GDCRNATools” package in R software. Kaplan-Meier survival analysis (log-rank test) and ROC curve analysis were used to indicate the diagnostic and prognostic values of the biomarkers.

Results

The differential expression data demonstrated that 2995 mRNAs, 205 lncRNAs, and 345 miRNAs were differentially expressed in COAD. The GO and KEGG pathway analysis indicated that the differentially expressed mRNAs were primarily enriched in canonical processes in cancer. The PPI network showed that the CDKN2A, CCND1, MYC, E2F, CDK4, BRCA2, CDC25B, and CDKN1A proteins were the critical hubs. In addition, the Kaplan-Meier analysis revealed that 215 mRNAs, 14 lncRNAs, and 39 miRNAs were associated with overall survival time in the patients. Also, the ceRNA network data demonstrated that three lncRNAs including MIR17HG, H19, SNHG1, KCNQ1OT1, MALAT1, GAS5, SNHG20, OR2A1-AS1, and MAGI2-AS3 genes were involved in the development of COAD.

Conclusions

Our data suggested several promising lncRNAs in the diagnosis and prognosis of patients with COAD.

MicroRNAs target the Wnt/β‑catenin signaling pathway to regulate epithelial‑mesenchymal transition in cancer (Review)

Epithelial‑mesenchymal transition (EMT), during which cancer cells lose the epithelial phenotype and gain the mesenchymal phenotype, has been verified to result in tumor migration and invasion. Numerous studies have shown that dysregulation of the Wnt/β‑catenin signaling pathway gives rise to EMT, which is characterized by nuclear translocation of β‑catenin and E‑cadherin suppression. Wnt/β‑catenin signaling was confirmed to be affected by microRNAs (miRNAs), several of which are down‑ or upregulated in metastatic cancer cells, indicating their complex roles in Wnt/β‑catenin signaling. In this review, we demonstrated the targets of various miRNAs in altering Wnt/β‑catenin signaling to promote or inhibit EMT, which may elucidate the underlying mechanism of EMT regulation by miRNAs and provide evidence for potential therapeutic targets in the treatment of invasive tumors.

CASC21, a FOXP1 induced long non-coding RNA, promotes colorectal cancer growth by regulating CDK6

Emerging studies indicate that long non-coding RNAs (lncRNAs) play crucial roles in colorectal cancer (CRC). Here, we reported lncRNA CASC21, which is induced by FOXP1, functions as an oncogene in CRC. We systematically elucidated its clinical significance and possible molecular mechanism in CRC. LncRNA expression in CRC was analyzed by RNA-sequencing data in TCGA. The expression level of CASC21 in tissues was determined by qRT-PCR. The functions of CASC21 was investigated by in vitro and in vivo assays (CCK8 assay, colony formation assay, EdU assay, xenograft model, flow cytometry assay, immunohistochemistry (IHC) and Western blot). Chromatin immunoprecipitation (ChIP), RNA immunoprecipitation (RIP) and luciferase reporter assays were utilized to demonstrate the potential mechanisms of CASC21. CASC21 is overexpressed in CRC and high CASC21 expression is associated with poor survival. Functional experiments revealed that CASC21 promotes CRC cell growth. Mechanistically, we found that CASC21 expressed predominantly in the cytoplasm. CASC21 could interact with miR-539-5p and regulate its target CDK6. Together, our study elucidated that CASC21 acted as an oncogene in CRC, which might serve as a novel target for CRC diagnosis and therapy.

Hypoxia-Induced miR-675-5p Supports β-Catenin Nuclear Localization by Regulating GSK3-β Activity in Colorectal Cancer Cell Lines

The reduction of oxygen partial pressure in growing tumors triggers numerous survival strategies driven by the transcription factor complex HIF1 (Hypoxia Inducible Factor-1). Recent evidence revealed that HIF1 promotes rapid and effective phenotypic changes through the induction of non-coding RNAs, whose contribution has not yet been fully described. Here we investigated the role of the hypoxia-induced, long non-coding RNA H19 (lncH19) and its intragenic miRNA (miR-675-5p) into HIF1-Wnt crosstalk. During hypoxic stimulation, colorectal cancer cell lines up-regulated the levels of both the lncH19 and its intragenic miR-675-5p. Loss of expression experiments revealed that miR-675-5p inhibition, in hypoxic cells, hampered β-catenin nuclear localization and its transcriptional activity, while lncH19 silencing did not induce the same effects. Interestingly, our data revealed that miRNA inhibition in hypoxic cells restored the activity of Glycogen Synthase Kinase 3β (GSK-3β) reducing the amount of P-Ser9 kinase, thus unveiling a role of the miR-675-5p in controlling GSK-3β activity. Bioinformatics analyses highlighted the serine/threonine-protein phosphatases PPP2CA, responsible for GSK-3β activation, among the miR-675-5p targets, thus indicating the molecular mediator through which miR-675-5p may control β-catenin nuclear localization. In conclusion, here we demonstrated that the inhibition of the hypoxia-induced non-coding RNA miR-675-5p hampered the nuclear localization of β-catenin by regulating GSK-3β activity, thus proposing the miR-675-5p as a new therapeutic target for the treatment of colorectal cancer.

Long non‑coding RNA H19 is involved in sorafenib resistance in hepatocellular carcinoma by upregulating miR‑675

Sorafenib is the first‑line treatment for advanced hepatocellular carcinoma (HCC). Since many HCC patients experience drug resistance, there is an urgent need to discover more effective therapeutic strategies to overcome drug resistance. Long non‑coding RNAs (lncRNAs) play an important role in tumor drug resistance. However, research on the role of lncRNA H19 in sorafenib resistance in HCC is quite limited. In the present study, CCK‑8 assay, RT‑qPCR, EdU staining, immunofluorescence staining, and western blot analysis were used to detect the effect of lncRNA H19 on sorafenib resistance of HCC cells. H19 expression was found to be negatively related to sorafenib sensitivity in HCC cells. Knockdown of lncRNA H19 elevated sorafenib sensitivity by suppressing epithelial‑mesenchymal transition (EMT) in HCC cells. H19 upregulated miR‑675 expression. miR‑675 inhibitor decreased the cell viability in sorafenib‑treated HCC cells, while miR‑675 overexpression had the opposite effect on the treated cells. When the cells were pretreated with miR‑675 mimic, H19 siRNA did not alter the effect of miR‑675 on sorafenib sensitivity. In conclusion, our study provides new clues for further clinical treatment of sorafenib‑resistant liver cancer patients.

Numb negatively regulates the epithelial-to-mesenchymal transition in colorectal cancer through the Wnt signaling pathway

Colorectal cancer (CRC) is one of the most common malignant tumors and is associated with a high mortality rate due to the lack of specific biomarkers available for early diagnosis, targeted therapies, and prognostic surveillance. In the present study, we investigated the function of Numb and its underlying mechanism in CRC. Immunohistochemical staining and clinicopathological analysis were used to assess the expression of Numb and its clinical significance in patients with CRC. Quantitative real-time polymerase chain reaction, cell proliferation, Western blot, wound healing, Transwell, and TOP/FOP flash reporter assays were used to investigate the function of Numb and its underlying mechanism in CRC. Numb expression was downregulated and negatively correlated with the depth of invasion, tumor size, metastasis, TNM stage, and epithelial-to-mesenchymal transition (EMT) markers in CRC specimens. Numb negatively regulates the EMT, proliferation, invasion, migration, and the Wnt signaling pathway in vitro, as well as tumor growth and metastasis in vivo. Furthermore, activation of the Wnt signaling pathway by Wnt-3A negated the effect of Numb overexpression, whereas inhibition of the Wnt signaling pathway by IWR-1 impaired the effect of the Numb knockdown on the EMT. We concluded that Numb downregulation is a common event in patients with CRC and is closely correlated with cancer progression and a poor prognosis. Numb functions as a tumor suppressor in CRC, and its tumor suppressor function is mediated by negative regulation of the EMT through the Wnt signaling pathway.NEW & NOTEWORTHY We investigate the function of Numb and its underlying mechanism in colorectal cancer through quantitative real-time polymerase chain reaction, cell proliferation, Western blot, wound healing, Transwell, and TOP/FOP flash reporter assays. We conclude that Numb can negatively regulate the epithelial-to-mesenchymal transition through the Wnt signaling pathway to inhibit the development of colorectal cancer.

Exploring prognostic potential of long noncoding RNAs in colorectal cancer based on a competing endogenous RNA network

BACKGROUND

Colorectal cancer (CRC) is one of the most prevalent tumors worldwide. Recently, long noncoding RNAs (lncRNAs) have been shown to influence tumorigenesis and tumor progression by acting as competing endogenous RNAs (ceRNAs). It is difficult to extract prognostic lncRNAs and useful bioinformation from most ceRNA networks constructed previously.

AIM

To construct a prognostic related ceRNA regulatory network and lncRNA related signature based on risk score in CRC.

METHODS

RNA transcriptome profile and clinical information of 506 CRC patients were downloaded from the Cancer Genome Atlas database. R packages and Perl program were used for data processing. Cox regression analysis was used for prognostic model construction. Quantitative real-time polymerase chain reaction was used to detect the expression of lncRNAs.

RESULTS

A prognostic-related ceRNA network was constructed, including 9 lncRNAs, 44 mRNAs, and 30 miRNAs. In addition, a four-lncRNA model was constructed using multivariate Cox regression analysis, which could be an independent prognostic model in CRC. The risk score for each patient was calculated, and the 506 patients were divided into high and low-risk groups (253 for each group) based on the median risk score. The results of the survival analysis showed that patients with a high-risk score had a poor survival rate. Furthermore, the predictive value of the four-lncRNA model was evaluated in GSE38832. Patient survival probabilities could be better predicted when combing the risk score and clinical features. Gene Set Enrichment Analysis results verified that a number of cancer-related signaling pathways were enriched with a high-risk score in CRC. Finally, we validated a novel lncRNA (LINC00488) using quantitative real-time polymerase chain reaction in 22 paired CRC patient tumor tissues compared to adjacent non-tumor tissues.

CONCLUSION

The four-lncRNA model could give better predictive value for CRC patients. Our understanding of the lncRNA-related ceRNA regulatory mechanism could provide a potential diagnostic indicator for CRC patients.

HANR Enhances Autophagy-Associated Sorafenib Resistance Through miR-29b/ATG9A Axis in Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide and chemoresistance is the main obstacle for effective treatments of HCC. Accumulating studies indicated that long non-coding RNAs (lncRNAs) contribute to the chemoresistance of human carcinoma. However, the functional role of HANR in autophagy-mediated chemoresistance of HCC is unknown.

Methods

The expressions of HANR, miR-29b and ATG9A in tissues and cell lines were detected by real-time quantitative PCR (RT-qPCR). The expression of autophagy-related protein LC3-I and LC3-II was evaluated by Western blotting. The cell viability and apoptosis were examined by CCK-8 and flow cytometry, respectively. Bioinformatics analysis and luciferase activity assay were applied to determine the downstream target gene of HANR or miR-29b. Xenograft experiment was used to detect the effect of HANR on tumor growth.

Results

In the present study, we demonstrated that HANR was notably overexpressed in sorafenib-resistant HepG2 (HepG2/sora) and sorafenib-resistant Huh7 (Huh7/sora) cells, and HANR enhanced sorafenib resistance by facilitating autophagy in HepG2/sora and Huh7/sora cells. Furthermore, we demonstrated that miR‑29b could directly interact with HANR and abolished HANR-induced sorafenib resistance by suppressing autophagy in HepG2/sora and Huh7/sora cells. Moreover, ATG9A was validated as a target of miR-29b and its overexpression obviously reversed the inhibitory effect of miR-29b on sorafenib resistance and autophagy. In addition, HANR could act as a competing endogenous RNA (ceRNA) to upregulate ATG9A expression by sponging miR-29b. Hence, HANR increased autophagy-related sorafenib resistance via inhibiting the miR-29b/ATG9A axis in HepG2/sora and Huh7/sora cells, indicating that it may be a potential target to prevent chemoresistance of HCC.

Conclusion

Our study revealed HANR enhanced sorafenib resistance by acting as an autophagy promoter by regulating miR-29b/ATG9A axis in sorafenib‑resistant HCC cells and might provide potential therapeutic strategies for HCC treatment.

Pirfenidone ameliorates the formation of choroidal neovascularization in mice

The formation and development of choroidal neovascularization (CNV) is accompanied by inflammation and fibrosis. Existing treatments are expensive and can cause irreversible complications. Pirfenidone (PFD) exerts anti‑inflammatory and anti‑fibrotic effects; however, its applications in the eye remain unclear. Male C57BL/6J mice (aged 6‑8 weeks) were used to explore whether PFD can inhibit the formation of laser‑induced CNV. The localization of transforming growth factor β2 (TGFβ2) was determined through immunofluorescent staining. After laser photocoagulation, the vehicle and PFD groups were intravitreally injected with 1 µl PBS and 1 µl 0.5% PFD, respectively. At day 7 after intravitreal injection, the expression of TGFβ2 and vascular endothelial growth factor (VEGF) was assessed. Fundus fluorescein angiography was performed to investigate the extent of fluorescence leakage, and the CNV areas were analyzed using a choroidal flat mount. The results demonstrated that, on day 7 after photocoagulation, the expression of TGFβ2 and VEGF was reduced in the experimental group. In addition, fluorescein angiography showed that the leakage area of CNV was significantly smaller in the PFD injection group than those observed in the control and vehicle groups. Moreover, the areas of CNV in the PFD injection group were smaller compared with those reported in the other two injection groups. Histopathological and TUNEL analyses performed on day 28 revealed that there were no notable abnormalities on the layers of the neural retina of PFD‑treated mice. In conclusion, intravitreal injection of PFD inhibited the formation of CNV in mice, likely via the downregulation of VEGF and TGFβ2, which did not cause damage to the mouse retina after 28 days of treatment.

LINC02595 promotes tumor progression in colorectal cancer by inhibiting miR-203b-3p activity and facilitating BCL2L1 expression

Colorectal cancer (CRC) is one of the most prevalent tumors worldwide. Recently, long noncoding RNAs (lncRNAs) have been recognized as key regulators in postgenomic biology. Numerous lncRNAs have been identified as diagnostic biomarkers and therapeutic targets. However, the molecular mechanisms underlying the role of lncRNAs in CRC progression are not fully understood. Differentially expressed lncRNAs and messenger RNAs were investigated using a microarray approach in five paired primary CRC tumor tissues and the corresponding nontumor tissues and confirmed in an additional 116 paired tissues and 21 inflammatory bowel disease tissues and 15 adjacent normal tissues by a quantitative real‐time polymerase chain reaction. We also performed comprehensive transcriptome profiling analysis on Gene Expression Omnibus and The Cancer Genome Atlas datasets. We identified LINC02595 and evaluated its clinical significance as a plasma biomarker. The function of LINC02595 was evaluated using a panel of in vivo and vitro assays, including cell counting kit‐8, colony formation, cell cycle, apoptosis, RNA fluorescence in situ hybridization, luciferase reporter, immunohistochemistry, and CRC xenografts. We found that LINC02595 is upregulated in tumor tissues and blood samples of patients with CRC and CRC cell lines. Functional research found that LINC02595 promotes CRC cell growth, influences the cell cycle, and reduces apoptosis in vitro and vivo. Mechanistically, LINC02595 promoted BCL2‐like 1 (BCL2L1) expression through miR‐203b‐3p sponging. Our research demonstrated that LINC02595 is an oncogene in CRC and established the presence of a LINC02595‐miR‐203b‐BCL2L1 axis in CRC, which might provide a new diagnostic biomarker and therapeutic targets for the treatment of this disease.

Emerging Roles of lncRNAs in the Formation and Progression of Colorectal Cancer

Colorectal cancer (CRC) is the primary cause of cancer-related death worldwide; however, specific and sensitive tools for the early diagnosis and targeted therapy of CRC are currently lacking. High-throughput sequencing technology revealed that gene expression of long-chain non-coding RNAs (lncRNAs) in a number of cancers directly or indirectly interferes with various biological processes. Emerging evidence suggests that lncRNAs regulate target genes and play an important role in the biological processes of malignancies, including CRC. Many carcinostatic/oncogenic lncRNAs have been identified as biomarkers for metastasis and prognosis in CRC; hence, they serve as therapeutic tools. In this article, we systematically review the literature on the disordered lncRNAs in CRC from four aspects: DNA transcription, RNA level regulation, post-translational level, and the translation of lncRNAs into polypeptides. Subsequently, we analyze the mechanism through which lncRNAs participate in the biological process of CRC. Finally, we discuss the application and prospects of these lncRNAs in CRC.

Long Noncoding RNA (lncRNA)-Mediated Competing Endogenous RNA Networks Provide Novel Potential Biomarkers and Therapeutic Targets for Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer and has a high metastasis and reoccurrence rate. Long noncoding RNAs (lncRNAs) play an important role in CRC growth and metastasis. Recent studies revealed that lncRNAs participate in CRC progression by coordinating with microRNAs (miRNAs) and protein-coding mRNAs. LncRNAs function as competitive endogenous RNAs (ceRNAs) by competitively occupying the shared binding sequences of miRNAs, thus sequestering the miRNAs and changing the expression of their downstream target genes. Such ceRNA networks formed by lncRNA/miRNA/mRNA interactions have been found in a broad spectrum of biological processes in CRC, including liver metastasis, epithelial to mesenchymal transition (EMT), inflammation formation, and chemo-/radioresistance. In this review, we summarize typical paradigms of lncRNA-associated ceRNA networks, which are involved in the underlying molecular mechanisms of CRC initiation and progression. We comprehensively discuss the competitive crosstalk among RNA transcripts and the novel targets for CRC prognosis and therapy.

LncRNA SLCO4A1-AS1 predicts poor prognosis and promotes proliferation and metastasis via the EGFR/MAPK pathway in colorectal cancer

It is universally acknowledged that long non-coding RNAs (lncRNAs) involved in tumorigenesis in human cancers. However, the function and mechanism of many lncRNAs in colorectal cancer (CRC) remain unclear. By analyzing the two sets of CRC-related gene microarrays data, downloaded from the Gene Expression Omnibus (GEO) database and the lncRNA expression in a set of RNA sequencing data, we found that lncRNA SLCO4A1-AS1 was significantly upregulated in CRC tissues. We then collected CRC tissue samples and verified that SLCO4A1-AS1 is highly expressed in CRC tissues. Furthermore, SLCO4A1-AS1 was also upregulated in the CRC cell line. In situ hybridization results showed that high expression of SLCO4A1-AS1 was associated with poor prognosis in patients with CRC. Next, we found that SLCO4A1-AS1 promoted CRC cell proliferation, migration, and invasion. Results of western blotting assays show that its mechanism may relate to the epidermal growth factor receptor (EGFR)/mitogen-activated protein kinase (MAPK) pathway. Therefore, SLCO4A1-AS1 may be a potential biomarker for CRC prognosis and a new target for colorectal cancer therapy.

LncRNA, a novel target biomolecule, is involved in the progression of colorectal cancer

Colorectal cancer is one of the most commonly diagnosed malignancies among males and females worldwide. Although China is a country with a low incidence of colorectal cancer, with the improvement of China's economy and lifestyle changes, the incidence rate in China has generally increased in recent years, and the morbidity and mortality of colorectal cancer rank fifth among those of all malignant tumours. Furthermore, despite recent improvements in screening strategies and treatments for colorectal cancer, the prognosis of advanced colorectal cancer is still poor, mainly due to the recurrence or distant metastasis of this disease. Thus, colorectal cancer still seriously threatens the health and life of people and is a major public health problem worthy of further study. Recently, accumulating evidence has revealed that colorectal carcinogenesis might be a multistep process driven by progressive genetic abnormalities, including changes in lncRNA expression. Moreover, a large number of studies have discovered and studied the abnormal expression of lncRNAs in colorectal cancer, providing a promising target for the diagnosis and treatment of colorectal cancer, which will promote human understanding of the pathogenesis of colorectal cancer and improve diagnosis and treatment. Therefore, in the present review, we mainly summarize the present status of colorectal cancer, the characteristics, functions and clinical perspectives of lncRNAs, and the current therapeutic methods used for colorectal cancer, especially the application of lncRNAs in the treatment of colorectal cancer. It is hoped that this review will give readers a new understanding of the roles of lncRNAs in colorectal cancer.

LncRNAs as Regulators of Autophagy and Drug Resistance in Colorectal Cancer

Colorectal cancer (CRC) is a common malignancy with 1. 8 million cases in 2018. Autophagy helps to maintain an adequate cancer microenvironment in order to provide nutritional supplement under adverse conditions such as starvation and hypoxia. Additionally, most of the cases of CRC are unresponsive to chemotherapy, representing a significant challenge for cancer therapy. Recently, autophagy induced by therapy has been shown as a unique mechanism of resistance to anticancer drugs. In this regard, long non-coding RNAs (lncRNAs) analysis are important for cancer detection, progression, diagnosis, therapy response, and prognostic values. With increasing development of quantitative detection techniques, lncRNAs derived from patients' non-invasive samples (i.e., blood, stools, and urine) has become into a novel approach in precision oncology. Tumorspecific GAS5, HOTAIR, H19, and MALAT are novels CRC related lncRNAs detected in patients. Nonetheless, the effect and mechanism of lncRNAs in cancer autophagy and chemoresistance have not been extensively characterized. Chemoresistance and autophagy are relevant for cancer treatment and lncRNAs play a pivotal role in resistance acquisition for several drugs. LncRNAs such as HAGLROS, KCNQ1OT1, and H19 are examples of lncRNAs related to chemoresistance leaded by autophagy. Finally, clinical implications of lncRNAs in CRC are relevant, since they have been associated with tumor differentiation, tumor size, histological grade, histological types, Dukes staging, degree of differentiation, lymph node metastasis, distant metastasis, recurrent free survival, and overall survival (OS).

Progranulin sustains STAT3 hyper-activation and oncogenic function in colorectal cancer cells

Persistent activation of Signal Transducer and Activator of Transcription (STAT)3 occurs in a high percentage of tumors, including colorectal cancer (CRC), thereby contributing to malignant cell proliferation and survival. Although STAT3 is recognized as an attractive therapeutic target in CRC, conventional approaches aimed at inhibiting its functions have met with several limitations. Moreover, the factors that sustain hyper-activation of STAT3 in CRC are not yet fully understood. The identification of tumor-specific STAT3 cofactors may facilitate the development of compounds that interfere exclusively with STAT3 activity in cancer cells. Here, we show that progranulin, a STAT3 cofactor, is upregulated in human CRC as compared to nontumor tissue/cells and its expression correlates with STAT3 activation. Progranulin physically interacts with STAT3 in CRC cells, and its knockdown with a specific antisense oligonucleotide (ASO) inhibits STAT3 activation and restrains the expression of STAT3-related oncogenic proteins, thus causing cell cycle arrest and apoptosis. Moreover, progranulin knockdown reduces STAT3 phosphorylation and cell proliferation induced by tumor-infiltrating leukocyte (TIL)-derived supernatants in CRC cell lines and human CRC explants. These findings indicate that CRC exhibits overexpression of progranulin, and suggest a role for this protein in amplifying the STAT3 pathway in CRC.

The functions of long non-coding RNAs in colorectal cancer

Colorectal cancer (CRC) is the third most prevalent malignant neoplasm worldwide. Recently, in terms of the mechanism of CRC, most studies have focused on protein-coding genes. However, studies have increasingly shown that long non-coding RNAs (lncRNAs) play crucial roles in the proliferation and metastasis of CRC. Investigating this molecular mechanism may provide potential diagnostic tools and therapeutic targets for CRC. This review closely examines the dysregulation of lncRNAs in CRC. On account of different mechanisms being involved in the occurrence and development of CRC, there are several categories of lncRNAs, including lncRNAs related to the Wnt/β-catenin pathway, epithelial mesenchymal transition, epigenetic regulation, angiopoiesis, and chemoresistance. This review summarizes lncRNAs related to the progression of CRC, which may provide insight into the mechanisms and potential markers for prognostic prediction and monitoring relapse of CRC.

Functional polymorphisms of the lncRNA H19 promoter region contribute to the cancer risk and clinical outcomes in advanced colorectal cancer

Background

The long non-coding RNA H19 plays critical roles in cancer occurrence, development, and progression. The present study is for the first time to evaluate the association of genetic variations in the H19 promoter region with advanced colorectal cancer (CRC) susceptibility, environmental factors, and clinical outcomes.

Methods

16 single-nucleotide polymorphisms (SNPs) were identified in the H19 gene promoter by DNA sequencing, and 3 SNPs among which including rs4930101, rs11042170, and rs2735970 further expanded samples with 572 advanced CRC patients and 555 healthy controls.

Results

We found that harboring SNP [rs4930101 (P = 0.009), rs2735970 (P = 0.003), and rs11042170 (P = 0.003)] or carrying more than one combined risk genotypes significantly increased the risk for CRC [P < 0.0001, adjusted OR (95% CI) 6.48 (2.97–14.15)]. In the correlation analysis with environmental factors, rs2735970 and gender, combined risk genotypes (> 1 vs. ≤ 1) and family history of cancer demonstrated significant interactions. Furthermore, a remarkably worse clinical outcome was found in combined risk genotypes (> 1 vs. ≤ 1), especially in CRC patients with body weight ≥ 61 kg, smoking, and first-degree family history of cancer (Log-rank test: P = 0.006, P = 0.018, and P = 0.013, respectively). More importantly, the multivariate Cox regression analyses further verified that combined risk genotypes > 1 showed a prognostic risk factor for CRC patients with body weight ≥ 61 kg (P = 0.002), smoking (P = 0.008), and family history of cancer (P = 0.006). In addition, MDR analysis consistently revealed that the combination of selected SNPs and nine known risk factors showed a better prediction prognosis and represented the best model to predict advanced CRC prognosis.

Conclusion

3 SNPs of rs4930101, rs11042170, and rs27359703 among 16 identified SNPs of H19 gene remarkably increased CRC risk. Furthermore, the combined risk genotypes had a significant impact on environmental factors and clinical outcomes in the advanced CRC patients with body weight ≥ 61 kg, ever-smoking, and first-degree family history of cancer. These data suggest that H19 promoter SNPs, especially these combined SNPs might be more potentially functional biomarkers in the prediction of advanced CRC risk and prognosis.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0895-x) contains supplementary material, which is available to authorized users.

LncRNA H19 regulates PI3K-Akt signal pathway by functioning as a ceRNA and predicts poor prognosis in colorectal cancer: integrative analysis of dysregulated ncRNA-associated ceRNA network

Background

It is becoming increasingly clear that cancers can rarely be ascribed to just one or a few genomic variations. Genes generally do not function alone, but in groups that function as “networks”. This study aimed to develop a competing endogenous RNA (ceRNA) network to elucidate the role of long non-coding RNA H19 in colorectal cancer.

Methods

Large-scale RNA-seq data was obtained from The Cancer Genome Atlas database. Differentially expressed RNAs were identified by bioinformatics analysis, and a competing endogenous RNA network was constructed. Functional enrichment analysis and correlation analysis between competing endogenous RNAs and clinical features were performed to reveal their roles in the tumorigenesis of colorectal cancer. To verify the conclusions derived from bioinformatics analysis, we investigated the effect of lncRNA H19 knockdown in human colorectal cancer cell lines HT-29 and HCT116.

Results

The present study successfully identify various cancer-specific lncRNAs and pseudogenes in CRC. The lncRNA/pseudogene–miRNA–mRNA ceRNA network was constructed using 10 lncRNAs, 5 pseudogenes, 122 mRNAs and 39 miRNAs. In the ceRNA network of CRC, H19 up-regulates various cancer-related mRNA by competitively sponging various miRNA, and participates in PI3K–Akt signaling pathway in this manner. Cox regression and correlation analysis showed that H19 and some other competing endogenous RNAs in the network are associated with poor prognosis and clinical parameters such as tumor grade and metastasis. Knockdown of H19 reduces the protein level of MET, ZEB1, and COL1A1 in vitro.

Conclusions

H19 regulates PI3K–Akt signal pathway through a competing endogenous RNA network and predicts poor prognosis in colorectal cancer. The pseudogene RPLP0P2 may be an important oncogene like H19 and needs to be studied further.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0866-2) contains supplementary material, which is available to authorized users.

Long non-coding RNA H19 promotes corneal neovascularization by targeting microRNA-29c

Long non-coding RNA (lncRNA) H19 has been implicated in tumor angiogenesis. However, whether H19 regulates the progression of corneal neovascularization (CNV) is unclear. The present study aimed to determine the function of H19 in CNV and its possible molecular mechanism. Here, we found that the H19 levels were remarkably increased in vascularized corneas and basic fibroblast growth factor (bFGF)-treated human umbilical vein endothelial cells (HUVECs). In vitro, H19 up-regulation promoted proliferation, migration, tube formation and vascular endothelial growth factor A (VEGFA) expression in HUVECs, and it was found to down-regulate microRNA-29c (miR-29c) expression. Bioinformatics analysis revealed that H19 mediated the above effects by binding directly to miR-29c. In addition, miR-29c expression was markedly reduced in vascularized corneas and its expression also decreased in bFGF-treated HUVECs in vitro. MiR-29c targeted the 3′ untranslated region (3′-UTR) of VEGFA and decreased its expression. These data suggest that H19 can enhance CNV progression by inhibiting miR-29c, which negatively regulates VEGFA. This novel regulatory axis may serve as a potential therapeutic target for CNV.

Whole transcriptome sequencing identifies crucial genes associated with colon cancer and elucidation of their possible mechanisms of action

PURPOSE

This study aimed to investigate the key long non-coding RNAs (lncRNAs) associated with colon cancer and elucidate their possible mechanisms of action.

PATIENTS AND METHODS

Eight early-stage (ES) colon tumor tissues, eight late-stage (LS) colon tumor tissues, and eight normal tissues were collected, and they were subjected to high-throughput RNA sequencing. Subsequently, comprehensive bioinformatics analyses, including the identification of differentially expressed mRNAs and lncRNAs, functional enrichment analysis, and construction of a protein-protein interaction network and an miRNA-lncRNA-mRNA regulatory network were performed. Additionally, the expression of key lncRNAs was verified using real-time quantitative PCR (qPCR).

RESULTS

In total, 549 common differentially expressed mRNAs and 30 common differentially expressed lncRNAs were identified in both the ES and LS colon cancer samples upon comparison with the normal samples. Functional enrichment analysis showed that KIAA0125 was significantly enriched in the PI3K-Akt signaling pathway and that MSTRG.35002.1 was markedly enriched in BMP signaling-related functions. Moreover, key miRNA-lncRNA-mRNA relationships, such as hsa-miR-29b-3p-KIAA0125-BCL2 and hsa-miR-29b-3p-MSTRG.35002.1-MMP2, were identified. Notably, the qPCR assay confirmed that KIAA0125 and MSTRG.35002.1 were significantly downregulated in both ES and LS colon tumor tissues compared with normal colon tissues.

CONCLUSION

Our findings indicate that key lncRNAs, including KIAA0125 and MSTRG.35002.1, may be involved in colorectal cancer (CRC) development. Downregulation of KIAA0125 may contribute to CRC development via sponging of hsa-miR-29b-3p to regulate BCL2 expression or regulating the PI3K-Akt signaling pathway. Downregulation of MSTRG.35002.1 may promote CRC development via sponging of hsa-miR-29b-3p to regulate MMP2 expression or regulating the BMP signaling pathway.

LncRNA-SNHG15 enhances cell proliferation in colorectal cancer by inhibiting miR-338-3p

The incidence and death rate of colorectal cancer (CRC) is very high, which brings great need to understand the early molecular events of CRC. These studies demonstrate that long noncoding RNA (lncRNA) plays an important role in the occurrence and development of human cancer. Small nucleolar RNA host gene 15 (SNHG15) was recently identified as a cancer‐related lncRNA. In this study, we aimed to evaluate the function and mechanism of SNHG15 in CRC. The expression of SNHG15 was detected by quantitative RT‐PCR (qRT‐PCR) in CRC tissues and matched noncancerous tissues (NCTs). CCK‐8 assay, colony formation assay, flow cytometric analysis, and nude mouse xenograft mode were used to examine the tumor‐promoting function of SNHG15 in vitro and in vivo. The binding relationship between SNHG15, miR‐338‐3p and the target genes of miR‐338‐3p were screened and identified by databases, qRT‐PCR, dual luciferase reporter assay and western blot. Our results showed that SNHG15 was up‐regulated in CRC tissues compared with paired NCTs (P < 0.0001). High level of SNHG15 expression predicted poor prognosis of CRC (P = 0.0051). SNHG15 overexpression could promote cell proliferation and inhibit cell apoptosis. Animal experiments showed that up‐regulation of SNHG15 promoted tumor growth in vivo. The results of mechanism experiments showed that SNHG15 could bind to miR‐338‐3p and block its inhibition on the expression and activity of FOS or RAB14. In conclusion SNHG15 promotes cell proliferation through SNHG15/miR‐338‐3p/FOS‐RAB14 axis in CRC.

The role of lncRNA MSC-AS1/miR-29b-3p axis-mediated CDK14 modulation in pancreatic cancer proliferation and Gemcitabine-induced apoptosis

Pancreatic ductal adenocarcinoma (PDAC) remains a leading cause of cancer-related death due to the failure of traditional therapies. In the present study, we attempted to construct a lncRNA-miRNA-mRNA network which may modulate PDAC cell proliferation and Gemcitabine-induced cell apoptosis starting from CDK14, a new member of the CDK family and an oncogene in many cancers. Based on TCGA data, a significant positive correlation was observed between lncRNA MSC-AS1 and CDK14. Moreover, MSC-AS1 expression was upregulated in PDAC tissues. Higher MSC-AS1 expression was correlated with poorer prognosis in patients with PDAC. MSC-AS1 knockdown in Panc-1 and BxPC-3 cells significantly inhibited the cell proliferation. Moreover, miR-29b-3p, which has been reported to act as a tumor suppressor, was predicted to bind to both MSC-AS1 and CDK14. Contrary to MSC-AS1, higher miR-29b-3p expression was correlated to better prognosis in patients with PDAC. In both PDAC cell lines, miR-29b-3p negatively regulated MSC-AS1 and CDK14. As confirmed using luciferase reporter gene and RIP assays, MSC-AS1 served as a ceRNA for miR-29b-3p to counteract miR-29b-mediated CDK14 repression. MSC-AS1 knockdown inhibited CDK14 protein levels and PDAC proliferation and enhanced gemcitabine-induced cell death and apoptosis while miR-29b-3p inhibition exerted an opposing effect; the effect of MSC-AS1 knockdown was partially attenuated by miR-29b-3p inhibition. Taken together, we demonstrated that MSC-AS1/miR-29b-3p axis modulates the cell proliferation and GEM-induced cell apoptosis in PDAC cell lines through CDK14. We provided a novel experimental basis for PDAC treatment from the perspective of lncRNA-miRNA-mRNA network.

LncRNA: An All-rounder in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease and is supposed to have both genetic and environmental backgrounds. Plenty of studies have demonstrated the roles of long non-coding RNAs (lncRNAs) in the initiation and development of RA. Numerous lncRNAs have been found to be dysregulated in RA and to be correlated with disease activity of RA, which indicates potential diagnostic roles of lncRNAs. In addition to working as biomarkers for RA, lncRNAs participate in many specific pathological processes including inflammation, aberrant proliferation, migration, invasion and apoptosis. Further screenings and researches are required to validate the clinical potentials of lncRNAs as diagnostic and therapeutic targets in RA.

Nucleolar and spindle associated protein 1 promotes metastasis of cervical carcinoma cells by activating Wnt/β-catenin signaling

Background

The primary obstacle to treat cervical cancer is its high prevalence of metastasis, which severely affects patients’ quality of life and survival time. Nucleolar and spindle associated protein 1 (NUSAP1) has been implicated in the development, progression, and metastasis in several types of cancer. However, its oncogenic role in cervical cancer remains unclear.

Methods

Western blot assay and immunohistochemistry were used to determine the expression of NUSAP1 in 21 clinical fresh Cervical cancer tissues and 233 clinicopathologically characterized cervical cancer specimens. The biological roles of NUSAP1 in the metastasis of cervical cancer were investigated both in vitro by EMT, Side population analysis and Transwell assays and so on, and in vivo using a mouse 4w model of hematogenous metastasis and lymph node metastasis. Bioinformatics analysis, luciferase reporter analysis, immunoprecipitation and immunoblotting of nuclear and cytoplasmic cellular fractions were applied to discern and examine the relationshipbetween NUSAP1 and its potential targets.

Results

The results demonstrated that NUSAP1 was upregulated in cervical cancer cells and tissues, correlated positively with metastasis and poor clinical outcome of patients. High expression of NUSAP1 promoted metastasis by enhancing cancer stem cell (CSC) traits and epithelial-mesenchyme transition (EMT) progression, while silencing of NUSAP1 reduced CSC traits and EMT progression. Mechanistically, upregulation of NUSAP1 induced SUMOylation of TCF4 via interacting with SUMO E3 ligase Ran-binding protein 2 (RanBP2) and hyperactivated Wnt/β-catenin signaling in cervical cancer cells. Additionally, NUSAP1-induced cervical cancer cells metastasis and the cancer stem cell phenotype were abrogated with the Wnt/β-catenin signaling inhibitor XAV-939 treatment. Importantly, co-therapy of conventional treatment and XAV-939 will provide a novel and effective treatment for NUSAP1-ovexpressed cervical cancer patients.

Conclusions

Our results demonstrate thatNUSAP1 upregulation contributes to metastasis of cervical cancer by promoting CSC properties and EMT via Wnt/β-catenin signaling and XAV-939 might serve as a potential tailored therapeutic option for patients with NUSAP1-ovexpressed cervical cancer.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1037-y) contains supplementary material, which is available to authorized users.

Identification of hub genes and outcome in colon cancer based on bioinformatics analysis

Background

Colon cancer is one of the leading malignant neoplasms worldwide. Until now, the concrete mechanisms of colonic cancerogenesis are largely unknown; identification of driven genes and pathways is, therefore, of great importance for monitoring and conquering this disease. This study aims to explore the potential biomarkers and therapeutic targets for colon cancer treatment.

Methods

The gene expression profile of GSE44076 from Gene Expression Omnibus database, including 98 primary colon cancers and 98 normal distant colon mucosa, was deeply analyzed. GEO2R tool was used to screen the differentially expressed genes (DEGs) between colon cancer tissues and normal samples. Gene Ontology analysis and Kyoto Encyclopedia of Genes and Genomes pathway analysis were performed for screening DEGs using Database for Annotation, Visualization and Integrated Discovery database and Panther database. Moreover, Search Tool for the Retrieval of Interacting Genes, Cytoscape software, and Molecular Complex Detection plug-in were used to visualize the protein-protein interaction of these DEGs.

Results

A total of 497 DEGs were obtained, including 129 upregulated genes mainly enriched in Hippo signaling pathway, Wnt signaling pathway, and cytokine-cytokine receptor interaction and 368 downregulated genes enriched in retinol metabolism, steroid hormone biosynthesis, drug metabolism, and chemical carcinogenesis. Using Molecular Complex Detection software, three important modules were selected from the protein-protein interaction network. Moreover, 20 hub genes with high degree of connectivity were selected, including COL1A1, CXCL5, GNG4, TIMP1, and so on. The Kaplan-Meier analysis for overall survival and correlation analysis were applied among the hub genes.

Conclusion

Taken together, DEGs, especially the hub genes such as COL1A1, might be the driven genes in colon cancer progression. More importantly, they might be the novel biomarkers for diagnosis and guiding therapeutic strategies of colon cancer.

Determination of Serum Exosomal H19 as a Noninvasive Biomarker for Bladder Cancer Diagnosis and Prognosis

Background

Long noncoding RNAs (lncRNA) contained in exosomes have been recognized as promising stable biomarkers in cancers. H19 is a well-known oncogenic lncRNA, but whether extracellular H19 is contained in exosomes and the clinical significance of exosomal H19 are poorly understood. The aim of this study was to assess serum-derived exosomal H19 lncRNA as a cancer predictive marker.

Material/Methods

Exosomes from serum of bladder cancer (BC) patients were isolated using the ExoQuick purification method and identified using transmission electron microscopy and nanoparticle tracking analysis. RT-qPCR was used for the measurement of H19 expression in serum or tissue samples.

Results

Serum H19 was little influenced by the treatment of RNase A alone but was dramatically downregulated when treated with RNase A and Triton ×100 simultaneously. The concentration of H19 was significantly higher in serum exosomes than in exosome-depleted supernatants in serum. Then, we validated that exosomal H19 is stable in serum by exposing serum samples to prolonged conditions of room temperature, 4°C, multiple freeze-thaw cycles, and low/high pH. Serum exosomal H19 of BC patients was positively correlated with total H19 level in paired BC tissues, and exosomal H19 was significantly downregulated in postoperative samples when compared to the paired preoperative samples. In addition, exosomal H19 level was significantly increased in serum of BC patients when compared to healthy people and benign disease patients. More importantly, Kaplan-Meier survival curve analysis showed that higher serum exosomal H19 level in BC patients was correlated with poorer survival.

Conclusions

Detection of serum exosomal H19 shed light on using exosomal lncRNAs as a noninvasive diagnostic and prognostic biomarker for BC patients.

Long Non-coding RNAs Contribute to the Inhibition of Proliferation and EMT by Pterostilbene in Human Breast Cancer

Background: There is increasing evidence that long non-coding RNAs (lncRNAs) are involved in the process of carcinogenesis and treatment using chemotherapy. Pterostilbene, a phytochemical agent with natural antioxidant and anti-inflammatory properties, has been shown to modulate oncogenic processes in many cancers. However, there has been limited research on the association between pterostilbene and the expression of lncRNAs.

Methods: MCF7 breast cancer cells were treated with various concentrations of pterostilbene and their gene expression profile was analyzed by quantitative real-time PCR, Western blotting and immunofluorescence.

Results: Treatment with pterostilbene inhibited cell proliferation and epithelial-to-mesenchymal transition (EMT), and increased cell apoptosis, autophagy and ER stress. The Akt/mTOR pathway was downregulated, but p38 MAPK/Erk signaling was activated in cells following treatment with pterostilbene. Pterostilbene increased the expression of the lncRNAs MEG3, TUG1, H19, and DICER1-AS1 whereas the expression of LINC01121, PTTG3P, and HOTAIR declined. Knockdown of lncRNA H19 resulted in a reduction of the cell invasion, with the cells becoming more sensitive to pterostilbene therapy.

Conclusions: These results suggest that efficient optimum disruption of lncRNA expression might possibly improve the anti-tumor effects of phytochemical agents, thus serving as a potential therapy for breast cancer.

Non-Coding RNAs in Breast Cancer: Intracellular and Intercellular Communication

Non-coding RNAs (ncRNAs) are regulators of intracellular and intercellular signaling in breast cancer. ncRNAs modulate intracellular signaling to control diverse cellular processes, including levels and activity of estrogen receptor α (ERα), proliferation, invasion, migration, apoptosis, and stemness. In addition, ncRNAs can be packaged into exosomes to provide intercellular communication by the transmission of microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) to cells locally or systemically. This review provides an overview of the biogenesis and roles of ncRNAs: small nucleolar RNA (snRNA), circular RNAs (circRNAs), PIWI-interacting RNAs (piRNAs), miRNAs, and lncRNAs in breast cancer. Since more is known about the miRNAs and lncRNAs that are expressed in breast tumors, their established targets as oncogenic drivers and tumor suppressors will be reviewed. The focus is on miRNAs and lncRNAs identified in breast tumors, since a number of ncRNAs identified in breast cancer cells are not dysregulated in breast tumors. The identity and putative function of selected lncRNAs increased: nuclear paraspeckle assembly transcript 1 (NEAT1), metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), steroid receptor RNA activator 1 (SRA1), colon cancer associated transcript 2 (CCAT2), colorectal neoplasia differentially expressed (CRNDE), myocardial infarction associated transcript (MIAT), and long intergenic non-protein coding RNA, Regulator of Reprogramming (LINC-ROR); and decreased levels of maternally-expressed 3 (MEG3) in breast tumors have been observed as well. miRNAs and lncRNAs are considered targets of therapeutic intervention in breast cancer, but further work is needed to bring the promise of regulating their activities to clinical use.

The Impact of miRNA in Colorectal Cancer Progression and Its Liver Metastases

Colorectal cancer (CRC) is one of the most commonly diagnosed malignancies with a high incidence and mortality rate. An essential challenge in colorectal cancer management is to identify new prognostic factors that could better estimate the evolution and treatment responses of this disease. Considering their role in cancer development, progression and metastasis, miRNAs have become an important class of molecules suitable for cancer biomarkers discovery. We performed a systematic search of studies investigating the role of miRNAs in colorectal progression and liver metastasis published until October 2018. In this review, we present up-to-date information regarding the specific microRNAs involved in CRC development, considering their roles in alteration of Wnt/βcatenin, EGFR, TGFβ and TP53 signaling pathways. We also emphasize the role of miRNAs in controlling the epithelial⁻mesenchymal transition of CRC cells, a process responsible for liver metastasis in a circulating tumor cell-dependent manner. Furthermore, we discuss the role of miRNAs transported by CRC-derived exosomes in mediating liver metastases, by preparing the secondary pre-metastatic niche and in inducing liver carcinogenesis in a Dicer-dependent manner.

Tumor‑released lncRNA H19 promotes gefitinib resistance via packaging into exosomes in non‑small cell lung cancer

Currently, resistance to tyrosine kinase inhibitors, such as gefitinib, has become one major obstacle for improving the clinical outcome of patients with metastatic and advanced-stage non-small cell lung cancer (NSCLC). While cell behavior can be modulated by long non-coding RNAs (lncRNAs), the contributions of lncRNAs within extracellular vesicles (exosomes) are largely unknown. To this end, the involvement and regulatory functions of lncRNA H19 wrapped by exosomes during formation of gefitinib resistance in human NSCLC were investigated. Gefitinib-resistant cell lines were built by continuously grafting HCC827 and HCC4006 cells into gefitinib-contained culture medium. RT-qPCR assays indicated that H19 was increased in gefitinib-resistant cells when compared to sensitive parent cells. Functional experiments revealed that silencing of H19 potently promoted gefitinib-induced cell cytotoxicity. H19 was secreted by packaging into exosomes and this packaging process was specifically mediated by hnRNPA2B1. H19 wrapped in exosomes could be transferred to non-resistant cells, thus inducing gefitinib resistance. Moreover, treatment-sensitive cells with exosomes highly-expressing H19 induced gefitinib resistance, while knockdown of H19 abrogated this effect. In conclusion, H19 promoted gefitinib resistance of NSCLC cells by packaging into exosomes. Therefore, exosomal H19 may be a promising therapeutic target for EGFR⁺ NSCLC patients.