Long non-coding RNA Linc00675 suppresses cell proliferation and metastasis in colorectal cancer via acting on miR-942 and Wnt/β-catenin signaling

Long noncoding RNA LINC00675 drives malignancy in acute myeloid leukemia via the miR-6809 -CDK6 axis

Hematological malignancies such as acute myeloid leukemia (AML) have a low cure rate and a high recurrence rate. Long noncoding RNAs (LNCs) are essential regulators of tumorigenesis and progression. The role of lncRNA LINC00675 in AML has rarely been reported. This study revealed elevated LINC00675 expression in AML that promotes proliferation and inhibits apoptosis. Mechanistically, LINC00675 combines with miR-6809 to promote the expression of CDK6 in vitro and in vivo. Immune-checkpoint genes were expressed more highly in LINC00675-high patients. A high level of LINC00675 expression may make patients more susceptible to palbociclib treatments. In conclusion, our study demonstrated that LINC00675 is an oncogenic lncRNA that enhances the malignancy of AML by upregulating CDK6 expression through miR-6809 sponging, providing a new perspective and feasible target for the diagnosis and treatment of AML.

RNA-binding protein CPSF6 regulates IBSP to affect pyroptosis in gastric cancer

BACKGROUND

Extensive evidence has illustrated the promotive role of integrin binding sialoprotein (IBSP) in the progression of multiple cancers. However, little is known about the functions of IBSP in gastric cancer (GC) progression.

AIM

To investigate the mechanism underlying the regulatory effects of IBSP in GC progression, and the relationship between IBSP and cleavage and polyadenylation factor 6 (CPSF6) in this process.

METHODS

The mRNA and protein expression of relevant genes were assessed through real-time quantitative polymerase chain reaction and Western blot, respectively. Cell viability was evaluated by Cell Counting Kit-8 assay. Cell invasion and migration were evaluated by Transwell assay. Pyroptosis was measured by flow cytometry. The binding between CPSF6 and IBSP was confirmed by luciferase reporter and RNA immunoprecipitation (RIP) assays.

RESULTS

IBSP exhibited higher expression in GC tissues and cell lines than in normal tissues and cell lines. IBSP knockdown suppressed cell proliferation, migration, and invasion but facilitated pyroptosis. In the exploration of the regulatory mechanism of IBSP, potential RNA binding proteins for IBSP were screened with catRAPID omics v2.0. The RNA-binding protein CPSF6 was selected due to its higher expression in stomach adenocarcinoma. Luciferase reporter and RIP assays revealed that CPSF6 binds to the 3'-untranslated region of IBSP and regulates its expression. Knockdown of CPSF6 inhibited cell proliferation, migration, and invasion but boosted pyroptosis. Through rescue assays, it was uncovered that the retarded GC progression mediated by CPSF6 knockdown was reversed by IBSP overexpression.

CONCLUSION

Our study highlighted the vital role of the CPSF6/IBSP axis in GC, suggesting that IBSP might be an effective bio-target for GC treatment.

Recent advances microRNAs and metabolic reprogramming in colorectal cancer research

Colorectal cancer (CRC) is a cancer with the highest incidence and mortality. Alteration of gene expression is the main pathophysiological mechanism of CRC, which results in disturbed signaling pathways and cellular metabolic processes. MicroRNAs are involved in almost all pathophysiological processes and are correlative with colorectal cancer metabolism, proliferation, and chemotherapy resistance. Metabolic reprogramming, an important feature of cancer, is strongly correlative with the development and prognosis of cancers, including colorectal cancer. MicroRNAs can target enzymes involved in metabolic processes, thus playing a regulatory role in tumor metabolism. The disorder of the signaling pathway is another characteristic of tumor, which induces the occurrence and proliferation of tumors, and is closely correlative with the prognosis and chemotherapy resistance of tumor patients. MicroRNAs can target the components of the signaling pathways to regulate their transduction. Understanding the function of microRNAs in the occurrence and proliferation of CRC provides novel insights into the optimal treatment strategies, prognosis, and development of diagnosis in CRC. This article reviews the relationship between CRC and microRNA expression and hopes to provide new options for the diagnosis and treatment of CRC.

Intratumoral Microbiota-Host Interactions Shape the Variability of Lung Adenocarcinoma and Lung Squamous Cell Carcinoma in Recurrence and Metastasis

Differences in tissue microbiota-host interaction between lung squamous cell carcinoma (LUSC) and lung adenocarcinoma (LUAD) about recurrence and metastasis have not been well studied. In this study, we performed bioinformatics analyses to identify the genes and tissue microbes significantly associated with recurrence or metastasis. All lung cancer patients were divided into the recurrence or metastasis (RM) group and the nonrecurrence and nonmetastasis (non-RM) group according to whether or not they had recurred or metastasized within 3 years after the initial surgery. Results showed that there were significant differences between LUAD and LUSC in gene expression and microbial abundance associated with recurrence and metastasis. Compared with non-RM, the bacterial community of RM had a lower richness in LUSC. In LUSC, host genes significantly correlated with tissue microbe, whereas host-tissue microbe interaction in LUAD was rare. Then, we established a novel multimodal machine learning model based on genes and microbes to predict the recurrence and metastasis risk of a LUSC patient, which achieves an area under the curve (AUC) of 0.81. In addition, the predicted risk score was significantly associated with the patient's survival. IMPORTANCE Our study elucidates significant differences in RM-associated host-microbe interactions between LUAD and LUSC. Besides, the microbes in tumor tissue could be used to predict the RM risk of LUSC, and the predicted risk score is associated with patients' survival.

Somatosensory neurons express specific sets of lincRNAs, and lincRNA CLAP promotes itch sensation in mice

Somatosensory neurons are highly heterogeneous with distinct types of neural cells responding to specific stimuli. However, the distribution and roles of cell-type-specific long intergenic noncoding RNAs (lincRNAs) in somatosensory neurons remain largely unexplored. Here, by utilizing droplet-based single-cell RNA-seq (scRNA-seq) and full-length Smart-seq2, we show that lincRNAs, but not coding mRNAs, are enriched in specific types of mouse somatosensory neurons. Profiling of lincRNAs from single neurons located in dorsal root ganglia (DRG) identifies 200 lincRNAs localized in specific types or subtypes of somatosensory neurons. Among them, the conserved cell-type-specific lincRNA CLAP associates with pruritus and is abundantly expressed in somatostatin (SST)-positive neurons. CLAP knockdown reduces histamine-induced Ca2+ influx in cultured SST-positive neurons and in vivo reduces histamine-induced scratching in mice. In vivo knockdown of CLAP also decreases the expression of neuron-type-specific and itch-related genes in somatosensory neurons, and this partially depends on the RNA binding protein MSI2. Our data reveal a cell-type-specific landscape of lincRNAs and a function for CLAP in somatosensory neurons in sensory transmission.

Preclinical Evaluation of a Novel Small Molecule LCC-21 to Suppress Colorectal Cancer Malignancy by Inhibiting Angiogenic and Metastatic Signatures

Colorectal cancer (CRC) is one of the most common cancers, and it frequently metastasizes to the liver and lymph nodes. Despite major advances in treatment modalities, CRC remains a poorly characterized biological malignancy, with high reported cases of deaths globally. Moreover, cancer stem cells (CSCs) and their microenvironment have been widely shown to promote colon cancer development, progression, and metastasis. Therefore, an understanding of the underlying mechanisms that contribute to the maintenance of CSCs and their markers in CRC is crucial in efforts to treat cancer metastasis and develop specific therapeutic targets for augmenting current standard treatments. Herein, we applied computational simulations using bioinformatics to identify potential theranostic markers for CRC. We identified the overexpression of vascular endothelial growth factor-α (VEGFA)/β-catenin/matrix metalloproteinase (MMP)-7/Cluster of Differentiation 44 (CD44) in CRC to be associated with cancer progression, stemness, resistance to therapy, metastasis, and poor clinical outcomes. To further investigate, we explored in silico molecular docking, which revealed potential inhibitory activities of LCC-21 as a potential multitarget small molecule for VEGF-A/CTNNB1/MMP7/CD44 oncogenic signatures, with the highest binding affinities displayed. We validated these finding in vitro and demonstrated that LCC-21 inhibited colony and sphere formation, migration, and invasion, and these results were further confirmed by a Western blot analysis in HCT116 and DLD-1 cells. Thus, the inhibitory effects of LCC-21 on these angiogenic and onco-immunogenic signatures could be of translational relevance as potential CRC biomarkers for early diagnosis.

Molecular Mechanisms of Noncoding RNA in the Occurrence of Castration-Resistant Prostate Cancer

Although several therapeutic options have been shown to improve survival of most patients with prostate cancer, progression to castration-refractory state continues to present challenges in clinics and scientific research. As a highly heterogeneous disease entity, the mechanisms of castration-resistant prostate cancer (CRPC) are complicated and arise from multiple factors. Among them, noncoding RNAs (ncRNAs), the untranslated part of the human transcriptome, are closely related to almost all biological regulation, including tumor metabolisms, epigenetic modifications and immune escape, which has encouraged scientists to investigate their role in CRPC. In clinical practice, ncRNAs, especially miRNAs and lncRNAs, may function as potential biomarkers for diagnosis and prognosis of CRPC. Therefore, understanding the molecular biology of CRPC will help boost a shift in the treatment of CRPC patients. In this review, we summarize the recent findings of miRNAs and lncRNAs, discuss their potential functional mechanisms and highlight their clinical application prospects in CRPC.

The clinical prognostic value of lncRNA FOXP4-AS1 in cancer patients: A meta-analysis and bioinformatics analysis based on TCGA datasets

BACKGROUND

The mortality and recurrence of patients with cancer is of high prevalence. Long non-coding RNA (lncRNA) forkhead box P4 antisense RNA 1 (FOXP4-AS1) is a promising lncRNA. There is increasing evidence that lncRNA FOXP4-AS1 is abnormally expressed in various tumors and is associated with cancer prognosis. This study was designed to identify the prognostic value of lncRNA FOXP4-AS1 in human malignancies.

METHODS

We searched electronic databases up to April 29, 2022, including PubMed, Cochrane Library, Embase, MEDLINE, and Web of Science. Eligible studies that evaluated the clinicopathological and prognostic role of lncRNA FOXP4-AS1 in patients with malignant tumors were included. The pooled odds ratios (ORs) and the hazard ratios (HRs) were calculated to assess the role of lncRNA FOXP4-AS1 using Stata/SE 16.1 software.

RESULTS

A total of 6 studies on cancer patients were included in the present meta-analysis. The combined results revealed that high expression of lncRNA FOXP4-AS1 was significantly associated with unfavorable overall survival (OS) (HR = 1.99, 95% confidence interval [CI]: 1.65-2.39, P < .00001), and poor disease-free survival (DFS) (HR = 1.81, 95% CI: 1.54-2.13, P < .00001) in a variety of cancers. In additional, the increase in lncRNA FOXP4-AS1 expression was also correlated with tumor size ((larger vs smaller) (OR = 3.16, 95% CI: 2.12-4.71, P < .00001), alpha-fetoprotein (≥400 vs <400) (OR = 3.81, 95%CI: 2.38-6.11, P = .83), lymph node metastasis (positive vs negative) (OR = 2.93, 95%CI: 1.51-5.68, P = .001), and age (younger vs older) (OR = 2.06, 95% CI: 1.41-3.00, P = .00002) in patients with cancer. Furthermore, analysis results using The Cancer Genome Atlas (TCGA) dataset showed that the expression level of lncRNA FOXP4-AS1 was higher in most tumor tissues than in the corresponding normal tissues, which predicted a worse prognosis.

CONCLUSIONS

In this meta-analysis, we demonstrate that high lncRNA FOXP4-AS1 expression may become a potential marker to predict cancer prognosis.

Targeting lncRNA/Wnt axis by flavonoids: A promising therapeutic approach for colorectal cancer

Despite the dramatic advances in our understanding of the etiology of colorectal cancer (CRC) in recent decades, effective therapeutic strategies are still urgently needed. Oncogenic mutations in the Wnt/β-Catenin pathway are hallmarks of CRC. Moreover, long non-coding RNAs (lncRNAs) as molecular managers are involved in the initiation, progression, and metastasis of CRC. Therefore, it is important to further explore the interaction between lncRNAs and Wnt/β-Catenin signaling pathway for targeted therapy of CRC. Natural phytochemicals have not toxicity and can target carcinogenesis-related pathways. Growing evidences suggest that flavonoids are inversely associated with CRC risk. These bioactive compounds could target carcinogenesis pathways of CRC and reduced the side effects of anti-cancer drugs. The review systematically summarized the progress of flavonoids targeting lncRNA/Wnt axis in the investigations of CRC, which will provide a promising therapeutic approach for CRC and develop nutrition-oriented preventive strategies for CRC based on epigenetic mechanisms. In the field, more epidemiological and clinical trials are required in the future to verify feasibility of targeting lncRNA/Wnt axis by flavonoids in the therapy and prevention of CRC.

Wnt signaling in colorectal cancer: pathogenic role and therapeutic target

Background

The Wnt signaling pathway is a complex network of protein interactions that functions most commonly in embryonic development and cancer, but is also involved in normal physiological processes in adults. The canonical Wnt signaling pathway regulates cell pluripotency and determines the differentiation fate of cells during development. The canonical Wnt signaling pathway (also known as the Wnt/β-catenin signaling pathway) is a recognized driver of colon cancer and one of the most representative signaling pathways. As a functional effector molecule of Wnt signaling, the modification and degradation of β-catenin are key events in the Wnt signaling pathway and the development and progression of colon cancer. Therefore, the Wnt signaling pathway plays an important role in the pathogenesis of diseases, especially the pathogenesis of colorectal cancer (CRC).

Objective

Inhibit the Wnt signaling pathway to explore the therapeutic targets of colorectal cancer.

Methods

Based on studying the Wnt pathway, master the biochemical processes related to the Wnt pathway, and analyze the relevant targets when drugs or inhibitors act on the Wnt pathway, to clarify the medication ideas of drugs or inhibitors for the treatment of diseases, especially colorectal cancer.

Results

Wnt signaling pathways include: Wnt/β-catenin or canonical Wnt signaling pathway, planar cell polarity (Wnt-PCP) pathway and Wnt-Ca²⁺ signaling pathway. The Wnt signaling pathway is closely related to cancer cell proliferation, stemness, apoptosis, autophagy, metabolism, inflammation and immunization, microenvironment, resistance, ion channel, heterogeneity, EMT/migration/invasion/metastasis. Drugs/phytochemicals and molecular preparations for the Wnt pathway of CRC treatment have now been developed. Wnt inhibitors are also commonly used clinically for the treatment of CRC.

Conclusion

The development of drugs/phytochemicals and molecular inhibitors targeting the Wnt pathway can effectively treat colorectal cancer clinically.

Crosstalk between lncRNAs in the apoptotic pathway and therapeutic targets in cancer

The assertion that a significant portion of the mammalian genome has not been translated and that non-coding RNA accounts for over half of polyadenylate RNA have received much attention. In recent years, increasing evidence proposes non-coding RNAs (ncRNAs) as new regulators of various cellular processes, including cancer progression and nerve damage. Apoptosis is a type of programmed cell death critical for homeostasis and tissue development. Cancer cells often have inhibited apoptotic pathways. It has recently been demonstrated that up/down-regulation of various lncRNAs in certain types of tumors shapes cancer cells' response to apoptotic stimuli. This review discusses the most recent studies on lncRNAs and apoptosis in healthy and cancer cells. In addition, the role of lncRNAs as novel targets for cancer therapy is reviewed here. Finally, since it has been shown that lncRNA expression is associated with specific types of cancer, the potential for using lncRNAs as biomarkers is also discussed.

LINC01315 accelerates the growth and epithelial-mesenchymal transition of colorectal cancer cells via activating the Wnt/β-catenin signal

The pathological roles of long non-coding RNAs (lncRNAs) in colorectal carcinoma (CRC) have been corroborated. To date, the pathological contributions of LINC01315 in the epithelial-mesenchymal transition (EMT) property of CRC are still ambiguous. By silencing LINC01315, we disclosed that LINC01315 promoted the growth, metastatic characteristics, and the EMT of CRC cells in vitro. Mechanistically, LINC01315 activated Wnt/β-catenin signaling. LINC01315 bound to the β-catenin promoter and activated its transcription. In rescue experiments, ectopic overexpression of β-catenin counteracted the inhibiting effector-triggered by LINC01315 deletion. In summary, this preliminary study brings new insights to the pathological significance of the LINC01315/Wnt/β-catenin signaling pathway in CRC.

Identification of novel prostate cancer genes in patients stratified by Gleason classification: role of antitumoral genes

Prostate cancer (PCa) is a tumor with a great heterogeneity, both at a molecular and clinical level. Despite its global good prognosis, cases can vary from indolent to lethal metastatic and scientific efforts are aimed to discern those with worse outcomes. Current prognostic markers, as Gleason score, fall short when it comes to distinguishing these cases. Identification of new early biomarkers to enable a better PCa distinction and classification remains a challenge. In order to identify new genes implicated in PCa progression we conducted several differential gene expression analyses over paired samples comparing primary PCa tissue against healthy prostatic tissue of PCa patients. The results obtained show that this approach is a serious alternative to overcome patient heterogeneity. We were able to identify 250 genes whose expression varies along with tissue differentiation—healthy to tumor tissue, 161 of these genes are described here for the first time to be related to PCa. The further manual curation of these genes allowed to annotate 39 genes with antitumoral activity, 22 of them described for the first time to be related to PCa proliferation and metastasis. These findings could be replicated in different cohorts for most genes. Results obtained considering paired differential expression, functional annotation and replication results point to: CGREF1, UNC5A, C16orf74, LGR6, IGSF1, QPRT and CA14 as possible new early markers in PCa. These genes may prevent the progression of the disease and their expression should be studied in patients with different outcomes.

CircPTK2 inhibits cell cisplatin (CDDP) resistance by targeting miR-942/TRIM16 axis in non-small cell lung cancer (NSCLC)

In recent years, the problem of cancer resistance has become more and more prominent, seriously affecting treatment efficiency. Circular RNAs (circRNAs) play an important role in cell progression and cancer mechanisms. However, there is a lack of systematic studies on its function in non-small cell lung cancer (NSCLC) resistance. CircPTK2, microRNA-942 (miR-942), and Tripartite motif 16 (TRIM16) levels were detected by Real-time quantitative reverse transcriptase PCR (qRT-PCR). Extracellular acidification rate (ECAR), glucose consumption, and lactate production were assessed using the Seahorse XF96 Glycolysis Analyzer, glucose, and lactate assay kits, respectively. The protein expression was measured with the western bolt Transwell assay was used to determine migration and invasion of transfected cells. (4-5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and flow cytometry were applied to carry out cell proliferation and apoptosis, respectively. The relationship among circPTK2, miR-942, and TRIM16 were determined by using the dual-luciferase reporter assay and RIP assay. circPTK2 (hsa_circ_0008305) and TRIM16 were low expressed, while miR-942 was significantly highly expressed in NSCLC tissues and cell lines. Moreover, overexpression of circPTK2 remarkably inhibited cell growth, metastasis, and glycolysis in A549/CDDP and H1299/CDDP cells. Promotion of miR-942 or inhibition of TRIM16 could reverse the effects of high circPTK2 expression on cell growth, metastasis, and glycolysis in A549/CDDP and H1299/CDDP cells. CircPTK2 overexpression inhibited the growth of A549/CDDP cells in vivo. Furthermore, circPTK2 weakened CDDP resistance of NSCLC through modulating miR-942/TRIM16 axis, providing a novel sight for the treatment of NSCLC and improving the understanding of the CDDP resistance mechanism of NSCLC.

Therapeutic strategies targeting Wnt/β‑catenin signaling for colorectal cancer (Review)

Colorectal cancer (CRC) is one of the most common carcinomas. Although great progress has been made in recent years, CRC survival remains unsatisfactory due to high metastasis and recurrence. Understanding the underlying molecular mechanisms of CRC tumorigenesis and metastasis has become increasingly important. Recently, aberrant Wnt/β‑catenin signaling has been reported to be strongly associated with CRC tumorigenesis, metastasis and recurrence. Therefore, the Wnt/β‑catenin signaling pathway has potential value as a therapeutic target for CRC. In the present review, the dysregulation of this pathway in CRC and the promoting or suppressing function of therapeutic targets on CRC were explored. In addition, the interaction between this pathway and epithelial‑mesenchymal transition (EMT), cell stemness, mutations, metastasis‑related genes and tumor angiogenesis in CRC cells were also investigated. Numerous studies on this pathway may help identify the potential diagnostic and prognostic markers and therapeutic targets for CRC.

The prominent role of miR-942 in carcinogenesis of tumors

As a family of short noncoding RNAs, MicroRNAs have been identified as possible biomarkers for cancer discovery and assist in therapy control due to their epigenetic involvement in gene expression and other cellular biological processes. In the present review, the evidence for reaching the clinical effect and the molecular mechanism of miR-942 in various kinds of cancer is amassed. Dysregulation of miR-942 amounts in different kinds of malignancies, as bladder cancer, esophageal squamous cell carcinoma, breast cancer, cervical cancer, gastric cancer, colorectal cancer, Kaposi's sarcoma, melanoma, Hepatocellular carcinoma, nonsmall-cell lung cancer, oral squamous cell carcinoma, osteosarcoma, ovarian cancer, pancreatic ductal adenocarcinoma, renal cell carcinoma, and prostate cancer has stated a considerable increase or decrease in its level indicating its function as oncogene or tumor suppressor. MiR-942 is included in cell proliferation, migration, and invasion through cell cycle pathways, including pathways of transforming growth factor-beta signaling pathways, Wnt pathway, JAK/STAT pathway, PI3K/AKT pathway, apoptosis pathway, hippo signaling pathway, lectin pathway, interferon-gamma signaling, signaling by G-protein coupled receptor, developmental genes, nuclear factor-kappa B pathway, Mesodermal commitment pathway, and T-cell receptor signaling in cancer. An important biomarker, MiR-942 is a potential candidate for prediction in several cancers. The present investigation introduced miR-942 as a prognostic marker for early discovery of tumor progression, metastasis, and development.

Functional Peptides Encoded by Long Non-Coding RNAs in Gastrointestinal Cancer

Gastrointestinal cancer is by far the most common malignancy and the most common cause of cancer-related deaths worldwide. Recent studies have shown that long non-coding RNAs (lncRNAs) play an important role in the epigenetic regulation of cancer cells and regulate tumor progression by affecting chromatin modifications, gene transcription, translation, and sponge to miRNAs. In particular, lncRNA has recently been found to possess open reading frame (ORF), which can encode functional small peptides or proteins. These peptides interact with its targets to regulate transcription or the signal axis, thus promoting or inhibiting the occurrence and development of tumors. In this review, we summarize the involvement of lncRNAs and the function of lncRNAs encoded small peptides in gastrointestinal cancer.

N6-Methyladenosine-regulated LINC00675 Suppress the Proliferation, Migration and Invasion of Breast Cancer cells via Inhibiting miR-513b-5p

Breast cancer (BC) is the most common cancer among women. LINC00675 and miR-513b-5p has been reported to be abnormally expressed in multiple types of cancers and modulate malignant phenotypes of cancer cells. However, to date, the functional role and underlying regulatory mechanism of LINC00675 and miR-513b-5p in BC remains largely unknown. Here, we found that LINC00675 was significantly downregulated in BC tissues and cell lines. Decrease of LINC00675 expression associated with higher tumor grade, lymphovascular invasion and shorter survival in BC patients. Functional experiments demonstrated that overexpression of LINC00675 suppressed BC cell proliferation, migration and invasion, whereas depletion of LINC00675 exerted opposite effects. Mechanistically, LINC00675 functioned as a competing endogenous RNA (ceRNA) to interact with miR-513b-5p and suppress its expression. Moreover, METTL3 increased the m⁶A methylation of LINC00675, which enhanced the association between LINC00675 and miR-513b-5p. Collectively, the central findings of our study suggest that LINC00675 represses BC progression through the inhibition of miR-513b-5p in a m⁶A-dependent manner.

A Novel Prognostic Prediction Model for Colorectal Cancer Based on Nine Autophagy-Related Long Noncoding RNAs

Introduction

Colorectal cancer (CRC) is the most common gastrointestinal cancer and has a low overall survival rate. Tumor–node–metastasis staging alone is insufficient to predict patient prognosis. Autophagy and long noncoding RNAs play important roles in regulating the biological behavior of CRC. Therefore, establishing an autophagy-related lncRNA (ARlncRNA)-based bioinformatics model is important for predicting survival and facilitating clinical treatment.

Methods

CRC data were retrieved from The Cancer Genome Atlas. The database was randomly divided into train set and validation set; then, univariate and multivariate Cox regression analyses were performed to screen prognosis-related ARlncRNAs for prediction model construction. Interactive network and Sankey diagrams of ARlncRNAs and messenger RNAs were plotted. We analyzed the survival rate of high- and low-risk patients and plotted survival curves and determined whether the risk score was an independent predictor of CRC. Receiver operating characteristic curves were used to evaluate model sensitivity and specificity. Then, the expression level of lncRNA was detected by quantitative real-time polymerase chain reaction, and the location of lncRNA was observed by fluorescence in situ hybridization. Additionally, the protein expression was detected by Western blot.

Results

A prognostic prediction model of CRC was built based on nine ARlncRNAs (NKILA, LINC00174, AC008760.1, LINC02041, PCAT6, AC156455.1, LINC01503, LINC00957, and CD27-AS1). The 5-year overall survival rate was significantly lower in the high-risk group than in the low-risk group among train set, validation set, and all patients (all p < 0.001). The model had high sensitivity and accuracy in predicting the 1-year overall survival rate (area under the curve = 0.717). The prediction model risk score was an independent predictor of CRC. LINC00174 and NKILA were expressed in the nucleus and cytoplasm of normal colonic epithelial cell line NCM460 and colorectal cancer cell lines HT29. Additionally, LINC00174 and NKILA were overexpressed in HT29 compared with NCM460. After autophagy activation, LINCC00174 expression was significantly downregulated both in NCM460 and HT29, while NKILA expression was significantly increased.

Conclusion

The new ARlncRNA-based model predicts CRC patient prognosis and provides new research ideas regarding potential mechanisms regulating the biological behavior of CRC. ARlncRNAs may play important roles in personalized cancer treatment.

Exosomal circEPB41L2 serves as a sponge for miR-21-5p and miR-942-5p to suppress colorectal cancer progression by regulating the PTEN/AKT signalling pathway

BACKGROUND

Exosomes contain many functional RNAs, including circular RNA (circRNA), which are critical for cancer progression. However, the role of exosomal circEPB41L2 in colorectal cancer (CRC) remains unclear.

METHODS

Exosomes were isolated from plasma and cells. The characteristics of the exosomes were identified using transmission electron microscopy and nanoparticle tracking analysis. The protein levels of exosome markers and PTEN/AKT-related markers were measured using Western blot analysis. The expression of circEPB41L2, microRNA (miR)-21-5p and miR-942-5p was verified by quantitative real-time PCR. The proliferation, apoptosis, migration and invasion of cells were determined using cell counting kit eight assay, colony formation assay, flow cytometry, wound healing assay and transwell assay. Biotin-labelled RNA pull-down assay, dual-luciferase reporter assay and RIP assay were conducted to evaluate the interaction between circEPB41L2 and miR-21-5p or miR-942-5p. The effects of exosomal circEPB41L2 on colorectal cancer tumour growth were confirmed using animal experiments.

RESULTS

CircEPB41L2 was downregulated in the exosomes from colorectal cancer patients and cells. Overexpressed circEPB41L2 inhibited colorectal cancer cell proliferation, migration, invasion and promoted apoptosis, as well as suppressed the activity of PTEN/AKT signalling pathway. CircEPB41L2 could sponge miR-21-5p or miR-942-5p. MiR-21-5p or miR-942-5p could reverse the inhibition effect of circEPB41L2 on colorectal cancer progression and PTEN/AKT signalling pathway. In addition, we discovered that circEPB41L2 was mainly located at exosomes. Exosomal circEPB41L2 also could restrain colorectal cancer progression and the activity of PTEN/AKT signalling pathway. Animal experiments suggested that exosomal-mediated circEPB41L2 inhibited colorectal cancer tumour growth.

CONCLUSION

Our data revealed that exosomal circEPB41L2 sponged miR-21-5p and miR-942-5p to repress colorectal cancer progression by regulating the PTEN/AKT signalling pathway.

MiRNA-Wnt signaling regulatory network in colorectal cancer

Colorectal cancer (CRC) is one of the common malignancies worldwide and the Wnt signaling pathway is recognized as the main disrupted pathway in this malignancy. MicroRNAs (miRNAs) are recognized to contribute to the pathogenesis of CRC by triggering or impeding the Wnt signaling pathway. In addition, transcriptional regulation of miRNAs by canonical Wnt signaling also participates in CRC cell progression. In this review, we present comprehensive literature of the existing data on the interaction of miRNAs and Wnt signaling that could be useful in future studies in the field of CRC management.

Long Noncoding RNA HCG11 Acts as a Tumor Suppressor in Gastric Cancer by Regulating miR-942-5p/BRMS1 Axis

The functions of long noncoding RNAs (lncRNAs) have been widely investigated in human cancers, including gastric cancer (GC). The purpose of this study was to elucidate the role of lncRNA HCG11 in GC. In this study, mRNA and protein expressions were detected by quantitative real-time polymerase chain reaction assays (RT-qPCR) and Western blot analysis. The proliferation ability of GC cells was examined by (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyl Tetrazolium Bromide) MTT assays. The invasion and migration abilities of GC cells were evaluated by Transwell assays. The binding sites between miR-942-5p and HCG11/BRMS1 were confirmed by dual-luciferase reporter assays. Results showed that LncRNA HCG11 was downregulated in GC cells. Functionally, overexpression of HCG11 inhibited GC cell proliferation, migration, and invasion. In addition, lncRNA HCG11 was found to act as a molecular sponge of miR-942-5p. Furthermore, miR-942-5p promoted GC progression by suppressing lncRNA HCG11 expression. Besides that, BRMS1 was confirmed as a direct target of miR-942-5p. More importantly, breast cancer metastasis suppressor 1 (BRMS1) inhibited GC progression by upregulating lncRNA HCG11 and downregulating miR-942-5p. In conclusion, LncRNA HCG11 inhibited cell proliferation, migration, and invasion in GC by sponging miR-942-5p and upregulating BRMS1.

The clinical prognostic value of lncRNA LINC00675 in cancer patients: A meta-analysis

A newly discovered long non-coding RNA (lncRNA) is associated with the progression of a variety of tumors. The purpose of this meta-analysis is to explore further the relationship between clinicopathological features and the prognostic value of LINC00675 in caners.We searched the various database, including PubMed, Web of Science, Cochrane Library, Embase together with Wanfang, and China National Knowledge Infrastructure for articles on LINC00675 and clinicopathological characteristics and prognosis of patients with cancers before February 20, 2020. According to the inclusion and exclusion criteria, the studies that meet the criteria were systematically collected through search keywords. The Newcastle Ottawa document quality assessment system was used to evaluate the quality of documents. The required data from literature were extracted, and the hazard ratio (HR), odds ratio (OR), and 95confidence interval (CI) were calculated using stata12.0 software and RevMan5.3 software.A total of 5 studies covering 462 patients were included in this meta-analysis to evaluate the prognostic value of LINC00675 in cancers. Our results showed that high LINC00675 expression was significantly correlated with poor overall survival (OS) (HR = 1.60, 95% CI: 1.23-2.08, P = .0005). Additionally, upregulated expression of LINC00675 was significantly associated with tumor node metastasis stage (OR = 1.74, 95% CI: 1.18-2.58, P = .006) and distant metastasis (OR = 2.22, 95% CI: 1.21-4.08, P = .01).Our study suggests that LINC00675 could be used as a biomarker to evaluate the prognosis of cancer patients. More studies to further confirm that the clinical value of LINC00675 in cancers will be required.

The Emerging Landscape of Long Non-Coding RNAs in Colorectal Cancer Metastasis

Colorectal cancer (CRC) is one of the most common gastrointestinal cancers, with extremely high rates of morbidity and mortality. The main cause of death in CRC is distant metastasis; it affects patient prognosis and survival and is one of the key challenges in the treatment of CRC. Long non-coding RNAs (lncRNAs) are a group of non-coding RNA molecules with more than 200 nucleotides. Abnormal lncRNA expression is closely related to the occurrence and progression of several diseases, including cancer. Recent studies have shown that numerous lncRNAs play pivotal roles in the CRC metastasis, and reversing the expression of these lncRNAs through artificial means can reduce the malignant phenotype of metastatic CRC to some extent. This review summarizes the major mechanisms of lncRNAs in CRC metastasis and proposes lncRNAs as potential therapeutic targets for CRC and molecular markers for early diagnosis.

GFI1-Mediated Upregulation of LINC00675 as a ceRNA Restrains Hepatocellular Carcinoma Metastasis by Sponging miR-942-5p

Hepatocellular carcinoma (HCC) is a common malignant liver tumor worldwide. Tumor recurrence and metastasis contribute to the bad clinical outcome of HCC patients. Substantial studies have displayed lncRNAs modulate various tumorigenic processes of many cancers. Our current work was aimed to investigate the function of LINC00675 in HCC and to recognize the potential interactions between lncRNAs and microRNAs. GFI1 can exhibit a significant role in the progression of human malignant tumors. Firstly, GFI1 was identified using real-time PCR in HCC tissues and cells. In this work, we indicated GFI1 was remarkably reduced in HCC tissues and cells. Meanwhile, GFI1 specifically interacted with the promoter of LINC00675. Up-regulation of LINC00675 obviously repressed the migration and invasion capacity of SMCC-7721 and QGY-7703 cells in vitro. Moreover, decrease of LINC00675 competitively bound to miR-942-5p that contributed to the miRNA-mediated degradation of GFI1, thus facilitated HCC metastasis. The ceRNA function of LINC00675 in HCC cells was assessed and confirmed using RNA immunoprecipitation assay and RNA pull-down assays in our work. Additionally, we proved overexpression of miR-942-5p promoted HCC progression, which was reversed by the up-regulation of GFI1. In summary, LINC00675 might act as a prognostic marker for HCC, which can inhibit HCC development via regulating miR-942-5p and GFI1.

LINC01315 silencing inhibits the aggressive phenotypes of colorectal carcinoma by sponging miR-205-3p

Long non-coding RNAs (lncRNAs) are important regulatory factors in the progression of cancers. In this study, we investigated the molecular mechanism of long intergenic non-coding 01315 (LINC01315) in inhibiting the aggressive characteristics of colorectal carcinoma (CRC) cells. We proved that LINC01315 was significantly upregulated in CRC. Knockdown of LINC01315 decreased CRC cell growth and invasion in vitro. Bioinformatics analysis and a luciferase reporter experiment showed direct binding between LINC01315 and miR-205-3p. Furthermore, LINC01315 positively modulated protein kinase AMP-activated catalytic subunit α 1 (PRKAA1) expression by serving as a "sponge" for miR-205-3p. Moreover, LINC01315 regulated the growth and invasive phenotypes of CRC cells by sponging miR-205-3p. Downregulation of LINC01315 remarkedly impaired the tumorigenicity of CRC cells in vivo in a transplanted tumour model. Altogether, our results demonstrated that downregulation of LINC01315 suppresses CRC progression by sponging miR-205-3p.

Circular RNA hsa_circ_0001785 inhibits the proliferation, migration and invasion of breast cancer cells in vitro and in vivo by sponging miR-942 to upregulate SOCS3

Circular RNAs (circRNAs) are a class of widely expressed noncoding RNA with significant regulatory potential discovered in recent years. The purpose of this study was to investigate the effects of hsa_circ_0001785 on the proliferation, migration and invasion of breast cancer (BC) cells in vivo and in vitro and the potential underlying molecular mechanism. In the present study, the expressions of hsa_circ_0001785 in five BC cells (T47D, MCF-7, MDA-MB-453, MDA-MB-231 and BT-549) and one normal breast cell (MCF-10A) were the first to examined by qRT-PCR. Then, we studied the biological function of hsa_circ_0001785 in BC by in vivo and in vitro experiments. CCK-8, clone formation, wound-healing and Transwell assays were performed to analyze the cellular proliferation, migration and invasion in vitro. The subcutaneous tumor model of nude mice was used for in vivo experiment. In addition, we determined that hsa_circ_0001785 acted as competing endogenous RNAs (ceRNAs) in BC by RNA immunoprecipitation (RIP) and dual-luciferase reporter assays. Results showed that the expressions of hsa_circ_0001785 were decreased in BC cells. Hsa_circ_0001785 overexpression inhibited the proliferation, migration, invasion of BC cells and tumor growth in nude mice. RIP and dual-luciferase reporter assay demonstrated that hsa_circ_0001785 could regulate the SOCS3 by sponging miR-942. In general, circular RNA hsa_circ_0001785 inhibits the proliferation, migration and invasion of BC cells by modulating the miR-942/SOCS3 signaling axis.

Circ0106714 inhibits tumorigenesis of colorectal cancer by sponging miR-942-5p and releasing DLG2 via Hippo-YAP signaling

This study aimed to investigate the role of circ0106714-miR-942-5p-discs large homolog 2 (DLG2), a novel interactome, in colorectal cancer (CRC). Circ0106714 was found to be the most significantly downregulated circular RNA in CRC using a bioinformatics method, and we researched whether the ability of circ0106714 to sponge miR-942-5p and release DLG2 could affect CRC development via Hippo-YES-associated protein (YAP) signaling. We first employed qRT-PCR and immunoblotting to detect messenger RNA (mRNA) and protein expression, respectively. Live imaging of mice tumor xenografts was then conducted to study the effect of circ0106714 on tumor progression in vivo. Reporter gene assays were subsequently conducted to verify the predicted targeting relationship between circ0106714, miR-942-5p, and DLG2 mRNA in SW480 and HCT116 cell lines. As well as using flow cytometry for both apoptosis and cell cycle profile analyses, CCK-8 and clone foci formation assays were performed to assess cell survival. Wound healing assay and transwell invasion assay were later carried out to evaluate the migration and invasion of the cell lines. Findings revealed that circ0106714 and DLG2 were significantly downregulated, while miR-942-5p was significantly upregulated in human CRC tissues and cell lines. However, circ0106714 upregulation significantly suppressed tumor progression in vivo and inhibited the malignancy phenotypes of tumor cells in vitro by targeting miR-942-5p. Also discovered in this research was that miR-942-5p could directly target DLG2 mRNA, thus enhancing the malignancy phenotypes of CRC cells. We even found that DLG2 overexpression resulted in enhanced phosphorylation of YAP, a critical downstream effector of DLG2. This downstream effector was demonstrated to have a tumor-suppressive capacity in CRC cell lines. In sum, circ0106714 could suppress CRC by sponging miR-942-5p and releasing DLG2, thus promoting YAP phosphorylation.

A small protein encoded by a putative lncRNA regulates apoptosis and tumorigenicity in human colorectal cancer cells

Long noncoding RNAs (lncRNAs) are often associated with polysomes, indicating coding potential. However, only a handful of endogenous proteins encoded by putative lncRNAs have been identified and assigned a function. Here, we report the discovery of a putative gastrointestinal-tract-specific lncRNA (LINC00675) that is regulated by the pioneer transcription factor FOXA1 and encodes a conserved small protein of 79 amino acids which we termed FORCP (FOXA1-Regulated Conserved Small Protein). FORCP transcript is undetectable in most cell types but is abundant in well-differentiated colorectal cancer (CRC) cells where it functions to inhibit proliferation, clonogenicity, and tumorigenesis. The epitope-tagged and endogenous FORCP protein predominantly localizes to the endoplasmic reticulum (ER). In response to ER stress, FORCP depletion results in decreased apoptosis. Our findings on the initial characterization of FORCP demonstrate that FORCP is a novel, conserved small protein encoded by a mis-annotated lncRNA that regulates apoptosis and tumorigenicity in well-differentiated CRC cells.

LINC00675 Suppresses Cell Proliferation and Migration via Downregulating the H3K4me2 Level at the SPRY4 Promoter in Gastric Cancer

Accumulating evidence indicates that long noncoding RNAs (lncRNAs) are dysregulated in diverse tumors and take a pivotal role in modulating biological processes. In our study, a decreased expression level of LINC00675 in gastric cancer (GC) was first determined by data from The Cancer Genome Atlas (TCGA) and was identified using specimens from GC patients. Then, in vitro and in vivo functional experiments elaborated that LINC00675 could suppress cell proliferation and migration in GC. Multiple differentially expressed genes (DEGs) in LINC00675-overexpressing cells were identified through RNA sequencing analysis. An RNA-binding protein immunoprecipitation (RIP) assay was conducted to reveal that LINC00675 competitively bound with lysine-specific demethylase 1 (LSD1). A coimmunoprecipitation (coIP) assay indicated that LINC00675 overexpression may strengthen the binding of LSD1 and H3K4me2, whereas the chromatin immunoprecipitation (ChIP) assay results verified lower expression of H3K4me2 at the sprouty homolog 4 (SPRY4) promoter region. Together, our research identified that LINC00675 was remarkably downregulated in GC tissues and cells relative to nontumor tissues and cells. LINC00675 could repress GC tumorigenesis and metastasis via competitively binding with LSD1 and intensifying the binding of LSD1 and its target H3K4me2. Importantly, this contributed to attenuated binding of H3K4me2 at the promoter region of oncogene SPRY4 and suppressed SPRY4 transcription, thus suppressing GC cell proliferation and migration.

LINC00675 activates androgen receptor axis signaling pathway to promote castration-resistant prostate cancer progression

The development of prostate cancer (PCa) from androgen-deprivation therapy (ADT) sensitive to castration resistant (CRPC) seriously impacts life quality and survival of PCa patients. Emerging evidence shows that long noncoding RNAs (lncRNAs) play vital roles in cancer initiation and progression. However, the inherited mechanisms of how lncRNAs participate in PCa progression and treatment resistance remain unclear. Here, we found that a long noncoding RNA LINC00675 was upregulated in androgen-insensitive PCa cell lines and CRPC patients, which promoted PCa progression both in vitro and in vivo. Knockdown of LINC00675 markedly suppressed tumor formation and attenuated enzalutamide resistance of PCa cells. Mechanistically, LINC00675 could directly modulate androgen receptor's (AR) interaction with mouse double minute-2 (MDM2) and block AR's ubiquitination by binding to it. Meanwhile, LINC00675 could bind to GATA2 mRNA and stabilize its expression level, in which GATA2 could act as a co-activator in the AR signaling pathway. Notably, we treated subcutaneous xenografts models with enzalutamide and antisense oligonucleotides (ASO) targeting LINC00675 in vivo and found that targeting LINC00675 would benefit androgen-deprivation-insensitive models. Our findings disclose that the LINC00675/MDM2/GATA2/AR signaling axis is a potential therapeutic target for CRPC patients.

Long noncoding RNA HCG11 inhibited growth and invasion in cervical cancer by sponging miR-942-5p and targeting GFI1

Long noncoding RNAs (lncRNAs) act as essential regulators in cancer tumorigenesis. Our study aimed to explore the underlying mechanism of lncRNA human leukocyte antigen complex group 11 (HCG11) in cervical cancer (CC) progression. Long noncoding RNA HCG11 was downregulated in CC. Functional assays demonstrated that lncRNA HCG11 inhibited CC cell proliferation and invasion. Then, we confirmed that lncRNA HCG11 could directly bind to miR-942-5p. Moreover, inhibition of miR-942-5p suppressed the growth and invasion of CC cells, and growth factor-independent transcription repressor 1 (GFI1) gene was the target gene of miR-942-5p. Long noncoding RNA HCG11 increased the expression of GFI1 and suppressed cell proliferation and invasion by acting as a miR-942-5p sponge. Finally, the overexpression of lncRNA HCG11 suppressed the proliferation and metastasis of CC cells in vivo.

LncRNA & Wnt signaling in colorectal cancer

The outlook for new therapeutic approaches is pivotal to ameliorate the deterioration caused by the abrogated Wnt signaling. Long non-coding RNAs (lncRNAs) are tiny molecules that have begun emerging as vital molecular manager for the regulation of various cellular processes at transcription and translation levels in the colorectal cancer (CRC). Targeting Wnt pathway with lncRNA seems a promising approach to eradicate CRC. However, little is known of their active role in commencing both apoptosis and proliferation in CRC. This article  reviews the importance of these molecules in the pathogenesis of CRC and also emphasizes on the development of new therapeutic strategies to cope with the Wnt mediated CRC.

TGF-β and WNT signaling pathways in cardiac fibrosis: non-coding RNAs come into focus

Cardiac fibrosis describes the inappropriate proliferation of cardiac fibroblasts (CFs), leading to accumulation of extracellular matrix (ECM) proteins in the cardiac muscle, which is found in many pathophysiological heart conditions. A range of molecular components and cellular pathways, have been implicated in its pathogenesis. In this review, we focus on the TGF-β and WNT signaling pathways, and their mutual interaction, which have emerged as important factors involved in cardiac pathophysiology. The molecular and cellular processes involved in the initiation and progression of cardiac fibrosis are summarized. We focus on TGF-β and WNT signaling in cardiac fibrosis, ECM production, and myofibroblast transformation. Non-coding RNAs (ncRNAs) are one of the main players in the regulation of multiple pathways and cellular processes. MicroRNAs, long non-coding RNAs, and circular long non-coding RNAs can all interact with the TGF-β/WNT signaling axis to affect cardiac fibrosis. A better understanding of these processes may lead to new approaches for diagnosis and treatment of many cardiac conditions. Video Abstract.

lncRNA LIFR-AS1 suppresses invasion and metastasis of non-small cell lung cancer via the miR-942-5p/ZNF471 axis

Background

MicroRNA 942-5p (miR-942-5p) has been reported to promote migration and invasion in non-small cell lung cancer (NSCLC), but the underlying mechanism is not completely understood. The interplay between long non-coding RNAs (lncRNAs) and miRNAs plays a crucial role in tumor progression.

Methods

In the present study, we performed bioinformatic and biochemical analyses to identify miR-942-5p-interacting lncRNAs. The function and clinical significance of the candidate lncRNA(s) in NSCLC were determined.

Results

We identified LIFR-AS1 as a pivotal miR-942-5p-interacting lncRNA. Overexpression of miR-942-5p caused a reduction of LIFR-AS1 in NSCLC cells. LIFR-AS1 showed the ability to sponge miR-942-5p, leading to derepression of ZNF471. Functionally, LIFR-AS1 overexpression inhibited NSCLC cell migration and invasion, whereas LIFR-AS1 silencing yielded an opposite effect. In vivo studies confirmed that LIFR-AS1 overexpression suppressed lung metastasis of NSCLC cells. Rescue experiments demonstrated that enforced expression of miR-942-5p or depletion of ZNF471 restored the migration and invasion capacity of LIFR-AS1-overexpressing cells. Moreover, overexpression of ZNF471 restrained NSCLC cell invasion. Clinically, LIFR-AS1 downregulation was significantly correlated with TNM stage, lymph node metastasis, and reduced overall survival in NSCLC patients.

Conclusions

we provide first evidence for the involvement of the LIFR-AS1/miR-942-5p/ZNF471 axis in NSCLC invasion and metastasis. LIFR-AS1 may represent a novel target for the treatment of NSCLC.

Long non-coding RNA LINC00675 is associated with bladder cancer metastasis and patient survival

BACKGROUND

Muscle-invasive bladder cancer (MIBC), a bladder cancer that spreads into the detrusor muscle of the bladder, leads to a poor outcome. Long noncoding RNA LINC00675 has been reported to play import roles in several cancer types, although its biological function and underlying mechanism in MIBC remain largely unclear.

METHODS

Eighty-nine patients with MIBC were enrolled in the present study. RNA expression was measured using a quantitative reverse transcription-polymerase chain reaction. Protein expression was detected using western blotting. Transwell assays were performed to analyze the abilities of bladder cancer cells to migrate and invade. An RNA microarray was carried out to analyze LINC00675-regulated mRNAs in bladder cancer cells.

RESULTS

We found that LINC00675 expression was decreased in MIBC tissues compared to matched normal tissues, and was correlated with lymph node-metastatic MIBC. MIBC patients with low expression of LINC00675 had worse survival rates than those with high expression. Functional investigation showed that ectopic expression of LINC00675 inhibited bladder cancer cell migration, invasion and proliferation, whereas LINC00675 knockdown presented an opposite effect. Mechanistically, we found that LINC00675 inhibited β-catenin and its downstream gene expression.

CONCLUSIONS

The findings of the present study suggest that LINC00675 regulates β-catenin expression, and is associated with bladder cancer metastasis and patient survival.

Long Non-Coding RNA LEF1-AS1 Promotes Migration, Invasion and Metastasis of Colon Cancer Cells Through miR-30-5p/SOX9 Axis

INTRODUCTION

Aberrant expression of long non-coding RNAs (lncRNAs) has been implicated in the tumorigenesis and progression of colon cancer. Lymphoid enhancer-binding factor 1 antisense RNA 1 (LEF1-AS1), a highly conserved and newly discovered long non-coding RNA, has been reported to be upregulated and correlated with poor prognosis in colon cancer, but the exact role of it remains uncertain.

MATERIALS AND METHODS

In our study, the biological functions of LEF1-AS1 in colon cancer were analyzed by cell viability assay, colony formation assay, scratch wound healing assay, transwell cell invasion assay, soft agar assay, luciferase reporter assay, pull down assay, tumor xenograft model and Western blot.

RESULTS

We found that LEF1-AS1 was upregulated in colon cancer patients and correlated with poor overall survival and recurrent-free survival. Besides, enforced expression of LEF1-AS1 in HT29 and T84 cells promoted migration, invasion, anchorage-independent growth, tumor xenograft formation and lung metastasis, while knockdown of LEF1-AS1 in COLO320 cells suppressed cell migration, invasion, anchorage-independent growth and tumor xenograft formation. In addition, LEF1-AS1 was directly interacted and inversely correlated with miR-30-5p in colon cancer, and SOX9 was a downstream target for miR-30-5p. LEF1-AS1 overexpression increased the expression level of SOX9, and restoration of SOX9 attenuated the effects caused by LEF1-AS1 knockdown in cell migration, invasion, anchorage-independent growth and tumor xenograft formation.

CONCLUSION

Our results indicated that LEF1-AS1 promoted migration, invasion and metastasis of colon cancer cells partially through miR-30-5p/SOX9 axis. The oncogenic LEF1-AS1 could be a potential prognostic biomarker for colon cancer.

Long non-coding RNA HANR as a biomarker for the diagnosis and prognosis of colorectal cancer

Previous work suggests that the long noncoding RNA HCC associated long non-coding RNA (HANR) is associated with hepatocellular carcinoma (HCC) progression, but its significance in the context of colorectal cancer (CRC) remains to be determined. Therefore, in this study we assessed the prognostic and diagnostic value of HANR in patients suffering from CRC.The HANR expression in 165 pairs of CRC cancer and adjacent non-cancerous prostate tissues was measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis. Student t test was conducted for intergroup comparison. Pearson correlation test was used for correlation analysis. Survival curves were carried out by the Kaplan-Meier method and evaluated using the log-rank test. Multivariable Cox proportional hazard risk regression model was performed to screen the independent factor affected the prognosis of CRC patients.In this study, levels of HANR were significantly higher in CRC tumor samples relative to adjacent normal tissue samples (P < .001). A ROC analysis suggested HANR expression could be reliably used to differentiate between normal and CRC tumor tissue. In addition, elevated HANR expression was positively correlated with more advanced and aggressive CRC features, such as a larger tumor size (P = .003), increased invasion depth (P = .012), and more advanced TNM stage (P = .011). Survival analyses revealed that elevated HANR expression was correlated with worse overall survival (P = .002) and disease-free survival (P = .003). A multivariate analysis further confirmed the relevance of HANR as an independent predictor of CRC patient outcomes.In summary, these results indicate that the lncRNA HANR is a promising prognostic indicator in CRC patients.

CircRNA hsa_circ_0074834 promotes the osteogenesis-angiogenesis coupling process in bone mesenchymal stem cells (BMSCs) by acting as a ceRNA for miR-942-5p

Bone tissue has a strong ability to repair itself. When treated properly, most fractures will heal well. However, some fractures are difficult to heal. When a fracture does not heal, it is called nonunion. Approximately, 5% of all fracture patients have difficulty healing. Because of the continuous movement of the fracture site, bone nonunion is usually accompanied by pain, which greatly reduces the quality of life of patients. Bone marrow mesenchymal stem cells (BMSCs) play an important role in the process of nonunion. Circular RNAs (circRNAs) are a unique kind of noncoding RNA and represent the latest research hotspot in the RNA field. At present, no studies have reported a role of circRNAs in the development of nonunion. After isolation of BMSCs from patients with nonunion, the expression of circRNAs in these cells was detected by using a circRNA microarray. Alkaline phosphatase and Alizarin red staining were used to detect the regulation of osteogenic differentiation of BMSCs by hsa_circ_0074834. The target gene of hsa_circ_0074834 was detected by RNA pull-down and double-luciferase reporter assay. The ability of hsa_circ_0074834 to regulate the osteogenesis of BMSCs in vivo was tested by heterotopic osteogenesis and single cortical bone defect experiments. The results showed that the expression of hsa_circ_0074834 in BMSCs from patients with nonunion was decreased. Hsa_circ_0074834 acts as a ceRNA to regulate the expression of ZEB1 and VEGF through microRNA-942-5p. Hsa_circ_0074834 can promote osteogenic differentiation of BMSCs and the repair of bone defects. These results suggest that circRNAs may be a key target for the treatment of nonunion.

MiR-942 regulates the function of breast cancer cell by targeting FOXA2

MicroRNA (MiR)-942 regulates the development of a variety of tumors, however, its function in breast cancer (BCa) has been less reported. Therefore, the present study investigated the regulatory effects of miR-942 on BCa cells. The expression of miR-942 in whole blood samples and BCa cell lines was detected by quantitative real-time (qRT)-PCR. Direct target gene for miR-942 was confirmed by dual-luciferase reporter assay. FOXA2 expression in adjacent tissues was detected by qRT-PCR. The effects of miR-942, or miR-942 with FOXA2, on the cell viability, proliferation, apoptosis, migration and invasion of BCa cells were determined by cell counting kit-8 (CCK-8), colony formation assay, flow cytometry, wound scratch and Transwell, respectively. The levels of N-Cadherin, E-Cadherin and Snail were determined by Western blot. Kaplan-Meier was used to explore the relationship among the expressions of miR-942 and FOXA2 and the prognosis of BCa patients. MiR-942 had high expressed in BCa, while its low expression significantly suppressed the cell viability, proliferation, migration and invasion of BCa, but increased cell apoptosis. Down-regulation of N-Cadherin and Snail and up-regulation of E-Cadherin were also induced by low-expression of miR-942. FOXA2, which was proved as the direct target gene for miR-942 and was low-expressed in BCa, partially reversed the effect of overexpressed miR-942 on promoting cell viability, proliferation, migration and invasion, and suppressed cell apoptosis. A lower survival rate was observed in BCa patients with a high expression of miR-942 and a low expression of FOXA2. MiR-942 promoted the progression of BCa by down-regulating the expression of FOXA2.

Gene and lncRNA co-expression network analysis reveals novel ceRNA network for triple-negative breast cancer

Breast cancer is the most frequently diagnosed malignancy among women, and triple-negative breast cancer (TNBC) is a highly aggressive subtype. Increasing evidence has shown that lncRNAs are involved in tumor growth, cell-cycle, and apoptosis through interactions with miRNAs or mRNAs. However, there is still limited data on ceRNAs involved in the molecular mechanisms underlying TNBC. In this study, we applied the weighted gene co-expression network analysis to the existing microarray mRNA and lncRNA expression data obtained from the breast tissues of TNBC patients to find the hub genes and lncRNAs involved in TNBC. Functional enrichment was performed on the module that correlated with Ki-67 status the most (Turquoise module). The hub genes in the Turquoise module were found to be associated with DNA repair, cell proliferation, and the p53 signaling pathway. We performed co-expression analysis of the protein-coding and lncRNA hub genes in the Turquoise module. Analysis of the RNA-seq data obtained from The Cancer Genome Atlas database revealed that the protein-coding genes and lncRNAs that were co-expressed were also differentially expressed in the TNBC tissues compared with the normal mammary tissues. On the basis of establishing the ceRNA network, two mRNAs (RAD51AP1 and TYMS) were found to be correlated with overall survival in TNBC. These results suggest that TNBC-specific mRNA and lncRNAs may participate in a complex ceRNA network, which represents a potential therapeutic target for the treatment of TNBC.

Identification of differentially expressed circRNAs and a novel hsa_circ_0000144 that promote tumor growth in gastric cancer

Background

Circular RNAs (circRNAs) are involved in regulating tumor pathogenesis. The mechanism of circRNAs in gastric cancer (GC) is still unknown. Our study aimed to identify differentially expressed circRNAs and assess a novel circRNA (hsa_circ_0000144) in the proliferation, migration, and invasion in GC.

Methods

Gene ontology (GO) enrichment and analyses of Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, pathway network, and the ceRNA regulatory network of hsa_circ_0000144 targeting miRNAs and mRNAs were performed with the help of bioinformatics using R language and Perl software. hsa_circ_0000144 expression and circRNA knockdown in GC cell lines were detected using quantitative PCR (qPCR) in vitro. Cell proliferation, migration, and invasion after circRNA knockdown were measured using the cell counting kit-8 assay and Transwell assay.

Results

The circRNA expression profile GSE78092 downloaded from the Gene Expression Omnibus database included three GC patients and three normal tissues. Thirty-two differentially expressed circRNAs comprised six upregulated circRNAs and 26 downregulated circRNAs. In particular, the ErbB signaling pathway, neurotrophin signaling pathway, cellular senescence, and pathways in bladder cancer and GC played the most important roles in the pathway network. The expression of hsa_circ_0000144 was upregulated in GC cell lines. Hsa_circ_0000144 knockdown suppressed tumor growth in vitro.

Conclusions

Hsa_circ_0000144 promotes GC cell proliferation, migration, and invasion, and the ceRNA regulatory network of hsa_circ_0000144 targeting miRNAs and mRNAs might be biomarkers for GC diagnosis and targeted therapy.

miR-942 promotes proliferation and metastasis of hepatocellular carcinoma cells by inhibiting RRM2B

Background

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death. MicroRNA-942 (miR-942) plays a critical role in promoting proliferation and metastasis of cancer cells and is associated with poor prognosis in some types of cancers. However, the prognostic value of miR-942 and its functional role in HCC remain unclear.

Materials and methods

Real-time PCR (RT-PCR) was used to detect the expression of miR-942 in HCC tissues and adjacent normal liver tissues. Next, the correlations between miR-942 expression and clinicopathological parameters including the survival rate were analyzed. Interaction between miR-942 and ribonucleotide reductase regulatory TP53 inducible subunit M2B (RRM2B) was determined by RT-PCR, Western blot and luciferase assay. The biological influence of miR-942 on HCC cell lines was studied using CCK-8 assay, colony formation assay and transwell assay in vitro. Western blot and RT-PCR were used to analyze the change of downstream genes after miR-942 mimics transfection.

Results

miR-942 was significantly up-regulated in HCC. Its high expression was associated with serum alanine transaminase level (P=0.0350), tumor size (P=0.0195), T stage (P=0.0045) and lymphatic metastasis (P=0.0013). High expression of miR-942 was associated with shorter overall survival and disease-free survival time of HCC patients. RRM2B was validated as a target gene of miR-942. miR-942 mimics markedly promoted the malignant phenotypes of Huh7 and MHCC97H cell lines, while its inhibitor had the opposite effect. miR-942 can regulate the downstream genes of RRM2B including Egr-1 and PTEN, markers of epithelial-mesenchymal transition and matrix metalloproteinases.

Conclusion

miR-942 may serve as a potential biomarker for HCC and its inhibitor may be a therapeutic agent for the treatment of this deadly disease.

Interactions among lncRNAs, miRNAs and mRNA in colorectal cancer

Long non-coding RNAs (lncRNAs) are longer than 200 nts non-coding transcripts and have recently emerged as one of the largest and significantly diverse RNA families whereas microRNAs (miRNAs) are highly conserved short single-stranded ncRNAs (∼18-22 nucleotides). As families of small and long evolutionarily conserved ncRNAs, lncRNAs activate and repress genes via a variety of mechanisms at both transcriptional and translational levels, while miRNAs regulate protein-coding gene expression mainly through mRNA degradation or silencing, These ncRNAs have been proved to be involved in multiple biological functions, such as proliferation, differentiation, migration, angiogenesis and apoptosis. Today, while majority of studies have focused on defining the regulatory functions of lncRNAs and miRNAs, limited information have now available for the mutual regulations of lncRNAs, miRNAs and mRNA. Thus, the underlying molecular mechanisms, in particularly the interactions among lncRNAs, miRNAs and mRNA in development, growth, metastasis and therapeutic potential of cancer still remain obscure. Colorectal cancer (CRC) is known as the third most common and fourth leading cancer death worldwide. Increasing evidence showed the close correlations among aberrant expressions of lncRNAs, miRNAs and the occurrence, development of CRC. This review summarize the potential links among these RNAs in following three areas: 1, The biogenesis and roles of miRNAs in CRC; 2, The biogenesis and functions of lncRNAs in CRC; 3, The interactions among lncRNAs, miRNAs and mRNA in tumorigensis, growth, progression, EMT formation, chemoradiotherapy resistance, and therapeutic potential in CRC. We believe that identifying diverging lncRNAs, miRNAs and relevant genes, their interactions and complex molecular regulatory networks will provide important clues for understanding the mechanism and developing novel diagnostic and therapeutic strategies for CRC. Further efforts are warranted to bring the promise of regulating their activities into clinical utilities.

circEPSTI1 regulates ovarian cancer progression via decoying miR-942

Increasing studies show that circular RNAs (circRNAs) play vital roles in tumour progression. But, how circRNAs function in ovarian cancer is mostly unclear. Here, we detected the expression of circEPSTI1 in ovarian cancer and explored the function of circEPSTI1 in ovarian cancer via a series of experiments. Then, we performed luciferase assay and RNA immunoprecipitation (RIP) assay to explore the competing endogenous RNA (ceRNA) function of circEPSTI1 in ovarian cancer. qRT-PCR verified that circEPSTI1 was overexpressed in ovarian cancer. Inhibition of circEPSTI1 suppressed ovarian cancer cell proliferation, invasion but promoted cell apoptosis. Luciferase assays and RIP assay showed that circEPSTI1 and EPSTI1 (epithelial stromal interaction 1) could directly bind to miR-942. And circEPSTI1 could regulate EPSTI1 expression via sponging miR-942. In summary, circEPSTI1 regulated EPSTI1 expression and ovarian cancer progression by sponging miR-942. circEPSTI1 could be used as a biomarker and therapeutic target in ovarian cancer.

Systematic identification of lincRNA-based prognostic biomarkers by integrating lincRNA expression and copy number variation in lung adenocarcinoma

Copy number alterations (CNAs) of lincRNAs act as one of important mechanisms in disrupting lincRNA expression which may play critical roles during tumorigenesis in lung adenocarcinoma (LUAD). The copy number alterations of lincRNAs can mark the spectrum of cancer progression and may serve as biomarkers for prognosis in LUAD, however it is rarely studied. We analyzed RNASeq data for 488 LUAD patients from TCGA portal and 58 healthy subjects to identify prognostic lincRNAs predictive of patient survival. Computational analysis entailing integration of expression and copy number alteration data revealed five prognostic lincRNAs: RBPMS-AS1, TDRKH-AS1, LINC00578, RP11-470 M17.2 and LINC00941. The copy number alterations in the LINC00578 and RP11-470 M17.2 genes were positively associated with the longer overall survival of LUAD patients. The CNA in LINC00941 was negatively associated with the longer overall survival. Copy number amplification significantly correlated with increased expression of TDRKH-AS1, which regulates telomere organization and EZH2-mediated epigenetic silencing of CDKN1A, CDKN1B and IL24. Decreased survival of LUAD patients was associated with high LINC00941 expression. The LINC00941 regulates the PI3K-AKT signaling pathway, focal adhesion by influencing potential targets, such as KRAS proto-oncogene GTPase and VEGFC. These lincRNA-based prognostic biomarkers may destroy important cancer-related biological processes contributing to LUAD prognosis. In summary, we demonstrate the prognostic potential of four differentially expressed lincRNAs with copy number alterations (RBPMS-AS1, TDRKH-AS1, LINC00578 and RP11-470 M17.2) that are positively associated with longer overall survival of LUAD patients. One differentially expressed lincRNA LINC00941 with copy number alterations was negatively associated with longer overall survival of LUAD patients.

The roles of Wnt/β-catenin signaling pathway related lncRNAs in cancer

Long noncoding RNAs (lncRNAs), with length of more than 200 nucleotides, are not translated into proteins but involved in multiple diverse diseases, especially tumorigenesis. The dysregulation of lncRNAs greatly contributes to the progression of various tumors through specific signaling pathways, including Wnt/β-catenin signaling pathway, which is associated with malignant features of tumors. The interactions between lncRNAs, which have specific expression characteristics in diverse cancer tissues, and Wnt/β-catenin signaling pathway, exhibit potential as novel biomarkers and therapeutic targets. In this review, we aim to present research findings on the roles of Wnt pathway-related lncRNAs and their effects on Wnt/β-catenin signaling to regulate tumorigenesis in different cancer types. Results may be used as basis to develop or improve strategies for treatment of different carcinomas.

Long non-coding RNA LINC01410 promotes colon cancer cell proliferation and invasion by inhibiting miR-3128

A previous study implied that long intergenic non-coding RNA 1410 (LINC01410) promotes angiogenesis and metastasis of gastric cancer. However, the role of LINC01410 in colon cancer (CC) has remained elusive. In the present study, LINC01410 was identified to be highly expressed in CC tissues compared to adjacent normal tissues. It was indicated that high expression of LINC01410 in CC tissues was associated with poor prognosis. Further functional study suggested that LINC01410 knockdown significantly reduced the proliferation and invasive capacity of HT-29 and SW620 cells, and inhibited the cell cycle. Regarding the mechanism, LINC01410 was indicated to serve as a sponge for microRNA (miR)-3128, as evidenced by a luciferase reporter assay. Furthermore, knockdown of LINC01410 significantly increased the levels of miR-3128. In addition, miR-3128 was markedly downregulated in CC tissues compared with that in adjacent normal tissues. A rescue assay revealed that inhibition of miR-3128 significantly abrogated the effects of LINC01410 knockdown on CC cell proliferation and invasion. In conclusion, the present study demonstrated that LINC01410 functions as an oncogene in CC, at least in part by directly inhibiting miR-3128.