lncRNA SNHG1 cooperated with miR-497/miR-195-5p to modify epithelial-mesenchymal transition underlying colorectal cancer exacerbation

LncRNA SNHG1 facilitates colorectal cancer cells metastasis by recruiting HNRNPD protein to stabilize SERPINA3 mRNA

Metastasis continues to negatively impact individuals diagnosed with colorectal cancer (CRC). Research has revealed the important role of long noncoding RNAs (lncRNAs) in CRC metastasis, but the underlying mechanisms remain unclear. Here, we revealed that the lncRNA small nucleolar RNA host gene 1 (SNHG1) is expressed at higher levels in metastatic CRC tissues than in primary CRC tissues, and that high lncRNA SNHG1 expression indicates poor patient outcomes. We found that lncRNA SNHG1 promotes the migration and invasion of tumor cells both in vivo and in vitro. Moreover, lncRNA SNHG1 increases serpin family A member 3 (SERPINA3) mRNA stability by interacting with the heterogeneous nuclear ribonucleoprotein D (HNRNPD) protein, and subsequently upregulates SERPINA3 expression. Moreover, HNRNPD and SERPINA3 reversed the effects of lncRNA SNHG1 knockdown on CRC cell metastasis. In conclusion, we report that the lncRNA SNHG1 recruits HNRNPD, in turn upregulating SERPINA3 expression and ultimately facilitating CRC cell migration and invasion. Targeting the lncRNA SNHG1/HNRNPD/SERPINA3 signaling pathway might be a therapeutic option for preventing CRC metastasis.

Clinical significance of circulating long non-coding RNA SNHG1 in type 2 diabetes mellitus and its association with cell proliferation of pancreatic β-cell

BACKGROUND

To explore the association of long non-coding RNA (lncRNA) SNHG1/ miR-195 axis with type 2 diabetes mellitus (T2DM) and islet function.

METHODS

The expression of SNHG1 and miR-195 was measured in T2DM patients and in healthy subjects. Correlation between indciators was evaluated using Pearson correlation analysis. INS-1 cells were used to perform the cell function assays. Insulin secretion by INS-1 was detected using ELISA. Cell counting kit-8 (CCK-8) and flow cytometry was used to detect cell proliferation and apoptosis. Luciferase report assay was to used to verify the target of SNHG1.

RESULTS

The expression of SNHG1 was increased and miR-195 level was decreased in the serum of T2DM patients. Both SNHG1 and miR-195 could be biomarkers for T2DM diagnosis. The fasting plasma glucose (FPG) and HbA1c were positively related to SNHG1 and negatively related to miR-195. SNHG1 inhibited insulin secretion, and cell proliferation and promoted apoptosis of INS-1 cells via binding to miR-195.

CONCLUSIONS

Detection of SNHG1 and miR-195 might predict T2DM. SNHG1 could suppress proliferation and insulin secretion, but promote apoptosis of INS-1 cells via sponging miR-195.

Long noncoding RNA small nucleolar RNA host gene 1 as a potential novel biomarker for intraperitoneal free cancer cells in colorectal cancer

Colorectal cancer (CRC) is a prevalent cancer with intraperitoneal free cancer cells (IFCCs) playing a significant role in prognosis, especially during surgeries. The identification of IFCCs is crucial for determining the stage and treatment of patients with CRC. Existing methods for IFCC detection, such as conventional cytology, immunocytochemistry (ICC), and polymerase chain reaction (PCR), have limitations in sensitivity and specificity. This study investigates the potential of long noncoding RNA (lncRNA) SNHG1 as a biomarker for detecting IFCCs in patients with CRC. Testing on a cohort of 91 patients with CRC and 26 patients with gastrointestinal benign disease showed that SNHG1 outperformed CEA in distinguishing CRC cells and detecting IFCCs across different disease stages. SNHG1 demonstrated higher sensitivity (76.1% vs. 43.1%) and specificity (68.4% vs. 52.3%) than CEA for IFCC detection in patients with CRC, suggesting its promising role as a clinical method for identifying IFCCs in CRC.

Isorhapontigenin inhibition of basal muscle-invasive bladder cancer attributed to its downregulation of SNHG1 and DNMT3b

BACKGROUND

Bladder cancer (BC) is among the most prevalent malignant urothelial tumors globally, yet the prognosis for patients with muscle-invasive bladder cancer (MIBC) remains dismal, with a very poor 5-year survival rate. Consequently, identifying more effective and less toxic chemotherapeutic alternatives is critical for enhancing clinical outcomes for BC patients. Isorhapontigenin (ISO), a novel stilbene isolated from a Gnetum found in certain provinces of China, has shown potential as an anticancer agent due to its diverse anticancer activities. Despite its promising profile, the specific anticancer effects of ISO on BC and the underlying mechanisms are still largely unexplored.

METHODS

The anchorage-independent growth, migration and invasion of BC cells were assessed by soft agar and transwell invasion assays, respectively. The RNA levels of SOX2, miR-129 and SNHG1 were quantified by qRT-PCR, while the protein expression levels were validated through Western blotting. Furthermore, methylation-specific PCR was employed to assess the methylation status of the miR-129 promoter. Functional assays utilized siRNA knockdown, plasmid-mediated overexpression, and chemical inhibition approaches.

RESULTS

Our study demonstrated that ISO treatment significantly reduced SNHG1 expression in a dose- and time-dependent manner in BC cells, leading to the inhibition of anchorage-independent growth and invasion in human basal MIBC cells. This effect was accompanied by the downregulation of MMP-2 and MMP-9 and the upregulation of the tumor suppressor PTEN. Further mechanistic investigations revealed that SOX2, a key upstream regulator of SNHG1, played a crucial role in mediating the ISO-induced transcriptional suppression of SNHG1. Additionally, we found that ISO treatment led to a decrease in DNMT3b protein levels, which in turn mediated the hypomethylation of the miR-129 promoter and the subsequent suppression of SOX2 mRNA 3'-UTR activity, highlighting a novel pathway through which ISO exerts its anticancer effects.

CONCLUSIONS

Collectively, our study highlights the critical role of SNHG1 downregulation as well as its upstream DNMT3b/miR-129/SOX2 axis in mediating ISO anticancer activity. These findings not only elucidate the mechanism of action of ISO but also suggest novel targets for BC therapy.

Deciphering the miRNA-mRNA Interaction Landscape between Breast Cancer and Triple-Negative Breast Cancer: An Integrated Bioinformatics Approach

Breast cancer (BC) is globally recognized as the second most prevalent form of cancer. It predominantly affects women and can be categorized into distinct types based on the overexpression of specific cancer receptors.The key receptors implicated in this context are the human epidermal growth factor receptor-2 (HER2), estrogen receptor (ER), and progesterone receptor (PR), alongside a particularly intricate subclass known as triple-negative breast cancer (TNBC). This subclassification is critical for the stratification of breast cancer and informs therapeutic decision-making processes. Due to a lack of therapeutic targets, such as growth factor receptors, TNBC is the most aggressive type. Hence, identifying targetable regulators such as miRNAs could pave the way for potential therapeutic interventions. To identify common differentially expressed mRNAs (DE-mRNAs) in BC, including TNBC, we leveraged two data sets from the GEO collection and The Cancer Genome Atlas (TCGA). Significant DE-mRNAs were identified through PPI, MCODE, CytoNCA, and CytoHubba analyses. Following this, miRNAs were predicted using mirDIP. We utilized GSE42568, GSE185645, and TCGA and identified 159 common DE-mRNAs. Using Cytoscape plug-ins, we identified the 10 most significant DE-mRNAs in BC. Using mirDIP, target miRNAs for 10 DE-mRNAs were identified. We conducted an advanced analysis on the TNBC GEO data set (GSE45498) to corroborate the significance of shared DE-mRNAs and DE-miRNAs in TNBC. We identified four downregulated DE-miRNAs, including hsa-miR-802, hsa-miR-1258, hsa-miR-548a-3p, and hsa-miR-2053, significantly associated with TNBC. Our study revealed significant miRNA-mRNA interactions, specifically hsa-miR-802/MELK, hsa-miR-1258/NCAPG, miR-548a-3p/CCNA2, and hsa-miR-2053/NUSAP1, in both BC and TNBC. The observed downregulation of hsa-miR-548a-3p is associated with diminished survival rates in BC patients, emphasizing their potential utility as prognostic indicators. Furthermore, the differential expression of mRNAs, including CCNB2, UBE2C, MELK, and KIF2C, correlates with reduced survival outcomes, signifying their critical role as potential targets for therapeutic intervention in both BC and TNBC. These findings highlight specific regulatory mechanisms that are potentially crucial for understanding and treating these cancer types.

miR-497/195 Cluster Affects the Development of Colorectal Cancer by Targeting FRA1

The miR-497-195 cluster facilitates the occurrence and development of cancer. This study aims to investigate whether the miR-195-497 cluster could regulate the progression of colorectal cancer by regulating the common target gene, FOS-related antigen 1 (FRA1). Overexpression of the miR-195/497 vector was used to evaluate the effect of overexpression of miR-195-497 clusters on the biological behavior of colon cancer cells. In animal experiments, tumor growth and metastasis were recorded by constructing a nude mouse model of a subcutaneously implanted tumor. miR-195 and miR-497 were expressed to varying degrees in Caco-2, LoVo, and HT-29 cells. Overexpression of miR-195/497 and inhibition of FRA1 decreased HT-29 cell proliferation, inhibited cell invasion and migration, and promoted Epithelial-mesenchymal transition (EMT). In vivo experiments showed that the overexpression of miR-195/497 or inhibition of FRA1 inhibited tumor growth, affected EMT in tumor cells, and inhibited the expression of FRA1. Additionally, the aforementioned conditions had the best effect when used together. The miR-195-497 cluster can regulate the proliferation, EMT, invasion, and migration of colorectal cancer cells by regulating the common target gene FRA1, thereby affecting the development of colorectal cancer.

Deciphering the functional landscape and therapeutic implications of noncoding RNAs in the TGF-β signaling pathway in colorectal cancer: A comprehensive review

Colorectal cancer (CRC) remains a major global health concern, necessitating an in-depth exploration of the intricate molecular mechanisms underlying its progression and potential therapeutic interventions. Transforming Growth Factor-β (TGF-β) signaling, a pivotal pathway implicated in CRC plays a dual role as a tumor suppressor in the early stages and a promoter of tumor progression in later stages. Recent research has shed light on the critical involvement of noncoding RNAs (ncRNAs) in modulating the TGF-β signaling pathway, introducing a new layer of complexity to our understanding of CRC pathogenesis. This comprehensive review synthesizes the current state of knowledge regarding the function and therapeutic potential of various classes of ncRNAs, including microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), in the context of TGF-β signaling in CRC. The intricate interplay between these ncRNAs and key components of the TGF-β pathway is dissected, revealing regulatory networks that contribute to the dynamic balance between tumor suppression and promotion. Emphasis is placed on how dysregulation of specific ncRNAs can disrupt this delicate equilibrium, fostering CRC initiation, progression, and metastasis. Moreover, the review provides a critical appraisal of the emerging therapeutic strategies targeting ncRNAs associated with TGF-β signaling in CRC. The potential of these ncRNAs as diagnostic and prognostic biomarkers is discussed, highlighting their clinical relevance. Additionally, the challenges and prospects of developing RNA-based therapeutics, such as RNA interference and CRISPR/Cas-based approaches, are explored in the context of modulating TGF-β signaling for CRC treatment. In conclusion, this review offers a comprehensive overview of the intricate interplay between ncRNAs and the TGF-β signaling pathway in CRC. By unraveling the functional significance of these regulatory elements, we gain valuable insights into the molecular landscape of CRC, paving the way for the development of novel and targeted therapeutic interventions aimed at modulating the TGF-β signaling cascade through the manipulation of ncRNAs.

ATG9A modulated by miR-195-5p can boost the malignant progression of cervical cancer cells

Cervical cancer (CC) is a major public health problem, and its molecular mechanism requires further investigation. The goal of this study was to determine the role of miR-195-5p and the autophagy-related protein ATG9A in tumour metastasis, epithelial - mesenchymal transition (EMT), apoptosis, and autophagy of CC cells. Using bioinformatics analysis, we predicted ATG9A as a downstream target gene of miR-195-5p, an integral membrane protein required for autophagosome formation and involved in tumorigenesis. Next, western blotting and Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) showed that upregulation of miR-195-5p decreased protein and mRNA expression of ATG9A, and downregulation of miR-195-5p promoted ATG9A protein and mRNA expression. In addition, detection of the dual luciferase reporter gene further indicated ATG9A is a direct downstream target gene of miR-195-5p. Finally, the effects of miR-195-5p and ATG9A on CC cell proliferation, migration, invasion, EMT, autophagy, and apoptosis were evaluated in vitro. Our results showed that upregulation of miR-195-5p not only inhibits proliferation, migration, and the EMT of CC cells, but also induces apoptosis and autophagy. Conversely, downregulation of miR-195-5p increased malignant metastasis and the EMT of CC cells, and inhibited apoptosis as well as autophagy. In addition, miR-195-5p targeted and negatively regulated ATG9A, and rescue experiments suggested that overexpression of ATG9A could partially abolish miR-195-5p-mediated suppression of CC cells. Our findings improve our understanding of the mechanism of action of miR-195-5p in the malignant behaviour of CC. miR-195-5p is likely to be a promising cancer suppressor gene, which provides clinical evidence for targeted therapy of CC.

LncRNA SNHG1: role in tumorigenesis of multiple human cancers

Small nucleolar RNA host gene 1 (SNHG1) is an important member of the SNHG family. This family is composed of a group of host genes that can be processed into small nucleolar RNAs and play important biological functions. In an oncogenic role, the SNHG1 expression is increased in various cancers, which has immense application prospects in the diagnosis, treatment, and prognosis of malignant tumors. In this review, we have summarized the role and molecular mechanism of SNHG1 in the development of various cancers. In addition, we have emphasized the clinical significance of SNHG1 in cancers in our article. This molecule is expected to be a new marker for potential usage in the diagnosis, prognosis, and treatment of cancer.

Linc-ROR Promotes EMT by Targeting miR-204-5p/SMAD4 in Endometriosis

Endometriosis (EMs) is a systemic and chronic disease with cancer-like feature, namely, distant implantation, which caused heavy healthy burden of nearly 200 million females. LncRNAs have been proved as new modulators in epithelial-mesenchymal transition (EMT) and EMs. Quantitative real-time PCR was conducted to measure the expression level of long intergenic non-protein coding RNA, regulator of reprogramming (Linc-ROR), and miR-204-5p in ectopic endometrium (n = 25), eutopic endometrium (n = 20), and natural control endometrium (n = 22). Overexpression of Linc-ROR, knockdown or overexpression of miR-204-5p in End1/E6E7 and Ishikawa cells, was conducted to detect the function of Linc-ROR and miR-204-5p in EMs. Furthermore, luciferase reports were used to confirm the combination of Linc-ROR and miR-204-5p and the combination between miR-204-5p and SMAD4. Cell-Counting Kit-8, EdU assay, transwell assays, and Western blotting were used to detect the function of Linc-ROR and miR-204-5p in EMs cancer-like behaviors and EMT process. Linc-ROR was up-regulated in ectopic endometrium. Overexpressed Linc-ROR promotes cell proliferation, invasion, and EMT process. Linc-ROR regulated the EMT process, cellular proliferation, and invasion of EMs via binding to miR-204-5p. In addition, overexpression of Linc-ROR up-regulated SMAD4, a target protein of miR-204-5p, with which regulated EMT process and cancer-like behaviors in EMs together. Linc-ROR/miR-204-5p/SMAD4 axis plays a vital role in regulation EMT process in EMs, which might become a novel therapeutic targets and powerful biomarkers in EMs therapy.

An epigenetic modulator with promising therapeutic impacts against gastrointestinal cancers: A mechanistic review on microRNA-195

Due to their high prevalence, gastrointestinal cancers are one of the key causes of cancer-related death globally. The development of drug-resistant cancer cell populations is a major factor in the high mortality rate, and it affects about half of all cancer patients. Because of advances in our understanding of cancer molecular biology, non-coding RNAs (ncRNAs) have emerged as critical factors in the initiation and development of gastrointestinal cancers. Gene expression can be controlled in several ways by ncRNAs, including through epigenetic changes, interactions between microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) and proteins, and the function of lncRNAs as miRNA precursors or pseudogenes. As lncRNAs may be detected in the blood, circulating ncRNAs have emerged as a promising new class of non-invasive cancer biomarkers for use in the detection, staging, and prognosis of gastrointestinal cancers, as well as in the prediction of therapy efficacy. In this review, we assessed the role lncRNAs play in the progression, and maintenance of colorectal cancer, and how they might be used as therapeutic targets in the future.

A Prognostic Cuproptosis-Related LncRNA Signature for Colon Adenocarcinoma

Background

Cuproptosis, a recently discovered form of cell death, is caused by copper levels exceeding homeostasis thresholds. Although Cu has a potential role in colon adenocarcinoma (COAD), its role in the development of COAD remains unclear.

Methods

In this study, 426 patients with COAD were extracted from the Cancer Genome Atlas (TCGA) database. The Pearson correlation algorithm was used to identify cuproptosis-related lncRNAs. Using the univariate Cox regression analysis, the least absolute shrinkage and selection operator (LASSO) was used to select cuproptosis-related lncRNAs associated with COAD overall survival (OS). A risk model was established based on the multivariate Cox regression analysis. A nomogram model was used to evaluate the prognostic signature based on the risk model. Finally, mutational burden and sensitivity analyses of chemotherapy drugs were performed for COAD patients in the low- and high-risk groups.

Result

Ten cuproptosis-related lncRNAs were identified and a novel risk model was constructed. A signature based on ten cuproptosis-related lncRNAs was an independent prognostic predictor for COAD. Mutational burden analysis suggested that patients with high-risk scores had higher mutation frequency and shorter survival.

Conclusion

Constructing a risk model based on the ten cuproptosis-related lncRNAs could accurately predict the prognosis of COAD patients, providing a fresh perspective for future research on COAD.

Association between small nucleolar RNA host gene expression and survival outcome of colorectal cancer patients: A meta-analysis based on PRISMA and bioinformatics analysis

Introduction

Growing evidence shows that long non-coding RNA small nucleolar RNA host genes (lncRNA SNHGs) enact an pivotal regulatory roles in the shorter survival outcome of colorectal cancer (CRC). However, no research has systematically evaluated the correlation among lncRNA SNHGs expression and survival outcome of CRC. This research indented to screen whether exist potential prognostic effect of lncRNA SNHGs in CRC patientss using comprehensive review and meta-analysis.

Methods

Systematic searches were performed from the six relevant databases from inception to October 20, 2022. The quality of published papers was evaluated in details. We pooled the hazard ratios (HR) with 95% confidence interval (CI) through direct or indirect collection of effect sizes, and odds ratios (OR) with 95% CI by collecting effect sizes within articles. Detailed downstream signaling pathways of lncRNA SNHGs were summarized in detail.

Results

25 eligible publications including 2,342 patients were finally included to appraise the association of lncRNA SNHGs with prognosis of CRC. Elevated lncRNA SNHGs expression was revealed in colorectal tumor tissues. High lncSNHG expression means bad survival prognosis in CRC patients (HR=1.635, 95% CI: 1.405-1.864, P<0.001). Additionally, high lncRNA SNHGs expression was inclined to later TNM stage (OR=1.635, 95% CI: 1.405-1.864, P<0.001), distant lymph node invasion, distant organ metastasis, larger tumor diameter and poor pathological grade. Begg's funnel plot test using the Stata 12.0 software suggested that no significant heterogeneity was found.

Conclusion

Elevated lncRNA SNHGs expression was revealed to be positively correlated to discontented CRC clinical outcome and lncRNA SNHG may act as a potential clinical prognostic index for CRC patients.

Identification of Tumor Suppressor Gene LHPP-Based 5-microRNA Signature That Predicts the Early- and Midstage Esophageal Squamous Cell Carcinoma: A Two-Stage Case-Control Study in the Chinese Han Population

Objective

To establish a novel approach for diagnosing early- and midstage esophageal squamous cell carcinoma (ESCC).

Methods

The tumor suppressor gene phospholysine phosphohistidine inorganic pyrophosphate phosphatase (LHPP)–based miRNA signature was identified using next-generation sequencing and 3 biological online prediction systems. This retrospective study established and validated an ESCC prediction model using a test cohort and a validation cohort.

Results

Immunohistochemical staining and real-time quantitative polymerase chain reaction (RT-qPCR) results showed that LHPP protein levels were significantly lower in tissues with early- and midstage ESCC than in adjacent tissues (P &lt; .01). Further, we confirmed that miR-15b-5p, miR-424-5p, miR-497-5p, miR-363-5p, and miR-195-5p inhibited LHPP. These 5 miRNAs were significantly elevated in the plasma of early- and midstage ESCC (P &lt; .05). An ESCC prediction model combining these 5 miRNAs was established. Finally, in the external validation cohort, the model exhibited high discriminative value (sensitivity/specificity: 84.4%/93.3%).

Conclusions

The prediction model has potential implications for diagnosis of early- and midstage ESCC.

LncRNA SNHG1 Facilitates Tumor Proliferation and Represses Apoptosis by Regulating PPARγ Ubiquitination in Bladder Cancer

Simple Summary

Our study elucidated that SNHG1 promotes MDM2 expression by binding to miR-9-3p to promote PPARγ ubiquitination and downregulate PPARγ expression and that SNHG1 plays an important role in bladder cancer and provides a potential therapeutic target for bladder cancer.

Abstract

Background: Long noncoding RNAs regulate various biological effects in the progression of cancers. We found that the expression of SNHG1 was significantly up-regulated in bladder cancer after analyzing data obtained from TCGA and GEO. However, the potential role of SNHG1 remains to be investigated in bladder cancer. It was validated that SNHG1 was overexpressed in bladder cancer tissues detected by qRT-PCR and FISH, which was also associated with poor clinical outcome. Additionally, SNHG1 was verified to facilitate tumor proliferation and repress apoptosis in vitro and in vivo. Results: SNHG1 could act as a competitive endogenous RNA and decrease the expression of murine double minute 2 (MDM2) by sponging microRNA-9-3p. Furthermore, MDM2 induced ubiquitination and degradation of PPARγ that contributed to the development of bladder cancer. Conclusions: the study elucidated that SNHG1 played an important role in bladder cancer and provided a potential therapeutic target for bladder cancer.

Roles and mechanisms of miR-195-5p in human solid cancers

Cancer persists as a worldwide disease that contributes to high morbidity and mortality rates. As a class of non-coding RNA, microRNAs (miRNAs) are one kind of important regulators in cancer and frequently implicated in tumor development and progression. Emerging experiments have suggested that miRNA-195-5p (miR-195-5p) can regulate neoplastic processes in many pathways. For instance, miR-195-5p can not only regulate proliferation, migration and invasion of tumor cells but also promote tumor cell apoptosis. Furthermore, low expression of miR-195-5p could induce drug resistance. Our review focuses on the expression of miR-195-5p in various tumors and elucidates the related mechanisms of which miR-195-5p participates in tumor biology, as well as summarizes the roles of miR-195-5p in tumor progression. We believe that miR-195-5p might have potential utility as a novel diagnostic biomarker and therapeutic target for cancer.

Potentials of long non-coding RNAs as biomarkers of colorectal cancer

Colorectal cancer (CRC) is the third most common malignant tumor worldwide and the fourth major cause of cancer-related death, with high morbidity and increased mortality year by year. Although significant progress has been made in the therapy strategies for CRC, the great difficulty in early diagnosis, feeble susceptibility to radiotherapy and chemotherapy, and high recurrence rates have reduced therapeutic efficacy resulting in poor prognosis. Therefore, it is urgent to understand the pathogenesis of CRC and unravel novel biomarkers to improve the early diagnosis, treatment and prediction of CRC recurrence. Long non-coding RNAs (lncRNAs) are non-coding RNAs with a length of more than 200 nucleotides, which are abnormally expressed in tumor tissues and cell lines, activating or inhibiting specific genes through multiple mechanisms including transcription and translation. A growing number of studies have shown that lncRNAs are important regulators of microRNAs (miRNAs, miRs) expression in CRC and may be promising biomarkers and potential therapeutic targets in the research field of CRC. This review mainly summarizes the potential application value of lncRNAs as novel biomarkers in CRC diagnosis, radiotherapy, chemotherapy and prognosis. Additionally, the significance of lncRNA SNHGs family and lncRNA-miRNA networks in regulating the occurrence and development of CRC is mentioned, aiming to provide some insights for understanding the pathogenesis of CRC and developing new diagnostic and therapeutic strategies.

Hsa_circ_0060927 participates in the regulation of Caudatin on colorectal cancer malignant progression by sponging miR-421/miR-195-5p

BACKGROUND

Caudatin is extracted from radix cynanchi bungei and has an inhibitory effect on cancer progression. The study aims to reveal the impacts of hsa_circ_0060927 on Caudatin-mediated colorectal cancer (CRC) development and the underneath mechanism.

METHODS

The expression levels of hsa_circ_0060927, microRNA-421 (miR-421) and miR-195-5p were detected by quantitative real-time reverse transcription-polymerase chain reaction. The protein expression was analyzed by Western blot or immunohistochemistry assay. Cell viability and proliferation were analyzed by 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide or 5-Ethynyl-29-deoxyuridine assay. Cell apoptosis was quantified by flow cytometry analysis. Cell migration and invasion were investigated by transwell assay. The putative associations among hsa_circ_0060927, miR-421 and miR-195-5p were predicted by the starbase online database, and identified by dual-luciferase reporter, RNA pull-down and RNA immunoprecipitation (RIP) assays. The impacts of Caudatin treatment on tumor growth in vivo were revealed by a xenograft tumor model assay.

RESULTS

Hsa_circ_0060927 expression was significantly upregulated, whereas miR-421 and miR-195-5p were downregulated in CRC tissues and cells compared with control groups. Hsa_circ_0060927 expression was closely associated with lymph node metastasis and tumor-node-metastasis stage. Caudatin treatment significantly decreased hsa_circ_0060927 expression but increased miR-421 and miR-195-5p expression. Caudatin exposure suppressed CRC cell proliferation, migration and invasion, and induced cell apoptosis; however, hsa_circ_0060927 overexpression hindered these impacts. Additionally, hsa_circ_0060927 was associated with miR-421/miR-195-5p. Depletion of miR-421 or miR-195-5p attenuated the influences of hsa_circ_0060927 silencing on CRC development. Furthermore, Caudatin treatment repressed tumor growth in vivo.

CONCLUSION

Caudatin inhibited CRC cell malignancy through the hsa_circ_0060927/miR-421/miR-195-5p pathway, which provided a potential therapeutic agent for CRC.

LncSNHG1 Promoted CRC Proliferation through the miR-181b-5p/SMAD2 Axis

Objective

To investigate the effects of LncRNA SNHG1 on the proliferation, migration, and epithelial-mesenchymal transition (EMT) of colorectal cancer cells (CRCs).

Methods

4 pairs of CRC tissue samples and their corresponding adjacent samples were analyzed by the human LncRNA microarray chip. The expression of LncSNHG1 in CRC cell lines was verified by qRT-PCR. Colony formation assays and CCK8 assays were applied to study the changes in cell proliferation. The transwell assay and wound healing experiments were used to verify the cell invasion and migration. EMT progression was confirmed finally.

Results

LncSNHG1 was overexpressed both in CRC tissues and cell lines, while the miR-181b-5p expression was decreased in CRC cell lines. After knock-down of LncSNHG1, the proliferation, invasion, and migration of HT29 and SW620 cells were all decreased. Meanwhile, LncSNHG1 enhanced EMT progress through regulation of the miR-181b-5p/SMAD2 axis.

Conclusion

LncSNHG1 promotes colorectal cancer cell proliferation and invasion through the miR-181b-5p/SMAD2 axis.

MicroRNAs and 'Sponging' Competitive Endogenous RNAs Dysregulated in Colorectal Cancer: Potential as Noninvasive Biomarkers and Therapeutic Targets

The gastrointestinal (GI) tract in mammals is comprised of dozens of cell types with varied functions, structures, and histological locations that respond in a myriad of ways to epigenetic and genetic factors, environmental cues, diet, and microbiota. The homeostatic functioning of these cells contained within this complex organ system has been shown to be highly regulated by the effect of microRNAs (miRNA). Multiple efforts have uncovered that these miRNAs are often tightly influential in either the suppression or overexpression of inflammatory, apoptotic, and differentiation-related genes and proteins in a variety of cell types in colorectal cancer (CRC). The early detection of CRC and other GI cancers can be difficult, attributable to the invasive nature of prophylactic colonoscopies. Additionally, the levels of miRNAs associated with CRC in biofluids can be contradictory and, therefore, must be considered in the context of other inhibiting competitive endogenous RNAs (ceRNA) such as lncRNAs and circRNAs. There is now a high demand for disease treatments and noninvasive screenings such as testing for bloodborne or fecal miRNAs and their inhibitors/targets. The breadth of this review encompasses current literature on well-established CRC-related miRNAs and the possibilities for their use as biomarkers in the diagnoses of this potentially fatal GI cancer.

Long Non-Coding RNA CCAT2 Activates RAB14 and Acts as an Oncogene in Colorectal Cancer

Here, we investigated the clinicopathological and prognostic potential of the long noncoding RNA Colon Cancer-Associated Transcript 2 (CCAT2) in human colorectal cancer (CRC). We used qPCR to quantify CCAT2 levels in 44 pairs of CRC tissues and adjacent nontumor and healthy colon mucosa tissues, and in several CRC cell lines (SW620, SW480, HT-29, LOVO, HCT116 and DLD-1) and normal human colorectal epithelial cells (HFC). We assessed the effects of CCAT2 overexpression or knockdown on the proliferation, migration and invasion by SW620 and LOVO cells using CCK-8, transwell, and wound-healing assays, respectively. We also investigated the potential interaction between CCAT2 and TAF15 through RNA pull down and rescue experiments. Lastly, we evaluated the expression of the cell cycle progression markers and GSK3β signaling pathway proteins using Western blotting. Our results showed that CCAT2 was upregulated in CRC tissues and cell lines as com-pared to controls. Ectopic expression of CCAT2 promoted CRC cell proliferation, migration and invasion, likely through direct interaction with TAF15, transcriptional activation of RAB14, and activation of the AKT/GSK3β signaling pathway. In vivo, CCAT2 promoted CRC cell growth and metastasis in nude mice. Taken together, these results highlight the actions of CCAT2 as a CRC oncogene.

Long non-coding RNA SNHG1 promotes fibroblast-to-myofibroblast transition during the development of pulmonary fibrosis induced by silica particles exposure

Inhaling silica dust in the environment can cause progressive pulmonary fibrosis, then silicosis. Silicosis is the most harmful occupational disease in the world, so the study of the mechanism is of great significance for the prevention and treatment of silicosis. Long non-coding RNAs (lncRNAs) are important players in the pathological process of fibrotic diseases. However, the function of specific lncRNA in regulating pulmonary fibrosis remains elusive. In this study, a mouse model of pulmonary fibrosis via intratracheal instillation of silica particles was established, and the differential expression of lnc-SNHG1 and miR-326 in lung tissues and TGF-β1-treated fibroblasts was detected by the qRT-PCR method. Short interfering RNA (siRNA) and plasmid were designed for knockdown or overexpression of lnc-SNHG1 in fibroblasts. MiRNA simulant was designed for overexpression of miR-326 in vivo and in vitro. Dual-luciferase reporter system, immunofluorescence, western blot, wound healing and transwell assay were performed to investigate the function and the underlying mechanisms of lnc-SNHG1. As a result, we found that lnc-SNHG1 was highly expressed in fibrotic lung tissues of mice and TGF-β1-treated fibroblasts. Moreover, the high expression of lnc-SNHG1 facilitated the migration and invasion of fibroblasts and the secretion of fibrotic molecules, while the low expression of lnc-SNHG1 exerted the opposite effects. Further mechanism studies showed that miR-326 was the potential target of lnc-SNHG1, and there is a negative correlation between the expression levels of lnc-SNHG1 and miR-326. Combined with mitigating fibrotic effects of miR-326 in a mouse model of silica particles exposure, we revealed that lnc-SNHG1 significantly sponged miR-326 and facilitated the expression of SP1, thus accelerating fibroblast-to-myofibroblast transition and synergistically promoting the development of pulmonary fibrosis. Our study uncovered a key mechanism by which lnc-SNHG1 regulated pulmonary fibrosis through miR-326/SP1 axis, and lnc-SNHG1 is a potential target for the prevention and treatment of silicosis.

METTL3-mediated mature miR-497-5p/195-5p inhibits trophoblast migration and invasion by targeting WWP1 in preeclampsia

Preeclampsia (PE) is a pregnancy-associated disorder caused by poor placentation. METTL3 as an RNA methyltransferase that plays an essential role in the regulation of the m6A modification. This work investigated the regulation of METTL3-mediated mature miR-497-5p/195-5p cluster in PE progression and identified the downstream mechanisms involved. Differentially expressed miRNAs in PE were obtained from the GSE96983 dataset. The miR-497-5p/195-5p levels in placental samples collected from 20 cases of PE patients and 18 cases of normal controls were measured by RT-qPCR. Effects of miR-497-5p/195-5p and WWP1 on trophoblast proliferation, migration, and invasion were analyzed by CCK8, EdU, wound healing and Transwell assays. Luciferase reporter and RIP experiments were conducted to verify the interaction of WWP1 with miR-497-5p/195-5p. Dot blot assay was performed to determine the m6A levels in PE. The m6A modification of pri-miR-497-5p/195-5p was determined by Me-RIP assay. Immunochemistry (IHC) and western blotting were used to examine the immunoreactivities and protein levels of METTL3 and WWP1 in placental samples from PE patients and normal controls. The miR-497-5p/195-5p levels were high in PE placenta. Functionally, overexpression of miR-497-5p/195-5p prevented trophoblast migration, invasion, and proliferation. WWP1 overexpression enhanced trophoblast migration, invasion, and proliferation. Mechanistically, WWP1 was verified to be targeted by miR-497-5p/195-5p. Moreover, METTL3 promoted the recognition of pri-miR-497-5p/195-5p by DGCR8 and enhanced the formation of mature miR-497-5p/195-5p in an m6A manner. We demonstrated that METTL3-mediated m6A modification promotes the transition of pri-miR-497-5p/195-5p to mature miRNAs, thereby upregulating miR-497-5p/195-5p to aggravate PE progression by targeting WWP1.

MicroRNAs as important contributors in the pathogenesis of colorectal cancer

Colorectal cancer (CRC) is the third most fatal and fourth most frequently diagnosed neoplasm in the world. Numerous non-coding RNAs have been shown to contribute in the development of CRC. MicroRNAs (miRNAs) are among the mostly assessed non-coding RNAs in CRC. These transcripts influence expression and activity of TGF-β, Wnt/β-catenin, MAPK, PI3K/AKT and other CRC-related pathways. In the context of CRC, miRNAs interact with long non-coding RNAs to influence CRC course. Stool and serum levels of miRNAs have been used to distinguish CRC patients from healthy controls, indicating diagnostic roles of these transcripts in CRC. Therapeutic application of miRNAs in CRC has been assessed in animal models, yet has not been verified in clinical settings. In the current review, we have provided a recent update on the role of miRNAs in CRC development as well as diagnostic and prognostic approaches.

Small nucleolar RNA host genes promoting epithelial-mesenchymal transition lead cancer progression and metastasis

The small nucleolar RNA host genes (SNHGs) belong to the long non-coding RNAs and are reported to be able to influence all three levels of cellular information-bearing molecules, that is, DNA, RNA, and proteins, resulting in the generation of complex phenomena. As the host genes of the small nucleolar RNAs (snoRNAs), they are commonly localized in the nucleolus, where they exert multiple regulatory functions orchestrating cellular homeostasis and differentiation as well as metastasis and chemoresistance. Indeed, worldwide literature has reported their involvement in the epithelial-mesenchymal transition (EMT) of different histotypes of cancer, being able to exploit peculiar features, for example, the possibility to act both in the nucleus and the cytoplasm. Moreover, SNHGs regulation is a fundamental topic to better understand their role in tumor progression albeit such mechanism is still debated. Here, we reviewed the biological functions of SNHGs in particular in the EMT process and discussed the perspectives for new cancer therapies.

Silenced SNHG1 Inhibited Epithelial-Mesenchymal Transition and Inflammatory Response of ARPE-19 Cells Induced by High Glucose

PURPOSE

The lncRNA small nucleolar RNA host gene 1 (SNHG1) is a cerebral infarction-associated gene, its biological role and mechanism in diabetic retinopathy remain to be illuminated. The present study was designed to investigate the role of SNHG1 in high glucose induced human retinal pigment epithelial cells (ARPE-19).

METHODS

ARPE-19 cells were cultured and exposed to 60 mM high glucose for 48h, and 5.5mM glucose-exposed ARPE-19 cells were used as the control. The levels of the epithelial-mesenchymal transition (EMT) markers E-cadherin, ZO-1, vimentin and α-SMA were measured, and the Cell inflammatory response was evaluated by detecting IL-6 and IL-1β levels. Then, cell migration, proliferation and apoptosis were detected. The expression of the lncRNA SNHG1 in ARPE-19 cells was detected by quantitative real-time PCR. SNHG1 was knocked down by small interfering RNA (siRNA) transfection. The effects of SNHG1 inhibition on inflammation, EMT, migration, proliferation and apoptosis were observed.

RESULTS

The results showed that the expression of SNHG1 was significantly increased in ARPE-19 cells exposed to high glucose. Silencing SNHG1 reduced the expression of vimentin, α-SMA, and the expression of inflammatory chemokines IL-6 and IL-1β, inhibited migration and proliferation, elevated the expression of E-cadherin and ZO-1, and promoted apoptosis in ARPE-19 cells.

CONCLUSION

The lncRNA SNHG1 is involved in hyperglycemia-induced EMT and the inflammatory response of ARPE-19 cells and provides a new understanding of the pathogenesis of DR.

Identification of Hub Genes and Construction of a Transcriptional Regulatory Network Associated With Tumor Recurrence in Colorectal Cancer by Weighted Gene Co-expression Network Analysis

Tumor recurrence is one of the most important risk factors that can negatively affect the survival rate of colorectal cancer (CRC) patients. However, the key regulators dictating this process and their exact mechanisms are understudied. This study aimed to construct a gene co-expression network to predict the hub genes affecting CRC recurrence and to inspect the regulatory network of hub genes and transcription factors (TFs). A total of 177 cases from the GSE17536 dataset were analyzed via weighted gene co-expression network analysis to explore the modules related to CRC recurrence. Functional annotation of the key module genes was assessed through Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses. The protein and protein interaction network was then built to screen hub genes. Samples from the Cancer Genome Atlas (TCGA) were further used to validate the hub genes. Construction of a TFs-miRNAs–hub genes network was also conducted using StarBase and Cytoscape approaches. After identification and validation, a total of five genes (TIMP1, SPARCL1, MYL9, TPM2, and CNN1) were selected as hub genes. A regulatory network of TFs-miRNAs-targets with 29 TFs, 58 miRNAs, and five hub genes was instituted, including model GATA6-MIR106A-CNN1, SP4-MIR424-TPM2, SP4-MIR326-MYL9, ETS1-MIR22-TIMP1, and ETS1-MIR22-SPARCL1. In conclusion, the identification of these hub genes and the prediction of the Regulatory relationship of TFs-miRNAs-hub genes may provide a novel insight for understanding the underlying mechanism for CRC recurrence.

The Impact of Non-coding RNAs in the Epithelial to Mesenchymal Transition

Epithelial to mesenchymal transition (EMT) is a course of action that enables a polarized epithelial cell to undertake numerous biochemical alterations that allow it to adopt features of mesenchymal cells such as high migratory ability, invasive properties, resistance to apoptosis, and importantly higher-order formation of extracellular matrix elements. EMT has important roles in implantation and gastrulation of the embryo, inflammatory reactions and fibrosis, and transformation of cancer cells, their invasiveness and metastatic ability. Regarding the importance of EMT in the invasive progression of cancer, this process has been well studies in in this context. Non-coding RNAs (ncRNAs) have been shown to exert critical function in the regulation of cellular processes that are involved in the EMT. These processes include regulation of some transcription factors namely SNAI1 and SNAI2, ZEB1 and ZEB2, Twist, and E12/E47, modulation of chromatin configuration, alternative splicing, and protein stability and subcellular location of proteins. In the present paper, we describe the influence of ncRNAs including microRNAs and long non-coding RNAs in the EMT process and their application as biomarkers for this process and cancer progression and their potential as therapeutic targets.

Molecular Characterization of the Oncogene BTF3 and Its Targets in Colorectal Cancer

Colorectal cancer (CRC) is one of the most commonly diagnosed and leading causes of cancer mortality worldwide, and the prognosis of patients with CRC remains unsatisfactory. Basic transcription factor 3 (BTF3) is an oncogene and hazardous prognosticator in CRC. Although two distinct functional mechanisms of BTF3 in different cancer types have been reported, its role in CRC is still unclear. In this study, we aimed to molecularly characterize the oncogene BTF3 and its targets in CRC. Here, we first identified the transcriptional targets of BTF3 by applying combined RNA-Seq and ChIP-Seq analysis, identifying CHD1L as a transcriptional target of BTF3. Thereafter, we conducted immunoprecipitation (IP)-MS and E3 ubiquitin ligase analysis to identify potential interacting targets of BTF3 as a subunit of the nascent-polypeptide-associated complex (NAC). The analysis revealed that BTF3 might also inhibit E3 ubiquitin ligase HERC2-mediated p53 degradation. Finally, miRNAs targeting BTF3 were predicted and validated. Decreased miR-497-5p expression is responsible for higher levels of BTF3 post-transcriptionally. Collectively, we concluded that BTF3 is an oncogene, and there may exist a transcription factor and NAC-related proteolysis mechanism in CRC. This study provides a comprehensive basis for understanding the oncogenic mechanisms of BTF3 in CRC.

miR-636 inhibits EMT, cell proliferation and cell cycle of ovarian cancer by directly targeting transcription factor Gli2 involved in Hedgehog pathway

Background

Hedgehog (Hh) signaling pathway, which is essential for cell proliferation and differentiation, is noted to be aberrantly activated in tumor from increasing studies in recent years. MicroRNAs (miRNAs) as an important non-coding RNA in cells have been proven to possess a regulatory role specific to the Hh signaling pathway. Here, in vitro and in vivo cellular/molecular experiments were adopted to clarify the regulatory mechanism linking miR-636 to the Hh signaling pathway in ovarian cancer (OVC).

Methods

Protein–protein interaction analysis was performed to identify the hub gene in the Hh pathway. TargetScan database was used to predict the potential upstream regulators for Gli2. qRT-PCR was performed to test the expression of miR-636, while Western blot was conducted to detect the expression of proteins related to the Hh pathway and epithelial-mesenchymal transition (EMT). For cell functional experiments, HO-8910PM OVC cell line was used. MTT assay and wound healing assay were used to measure the effect of miR-636 on cell proliferation and migration. Flow cytometry was carried out to examine the effect of miR-636 on cell cycle, and Western blot was used to identify the change in expression of Hh and EMT-related proteins. Dual-luciferase reporter gene assay was implemented to detect the targeting relationship between miR-636 and Gli2. Xenotransplantation models were established for in vivo examination.

Results

Gli2 was identified as the hub gene of the Hh pathway and it was validated to be regulated by miR-636 based on the data from TargetScan and GEO databases. In vitro experiments discovered that miR-636 was significantly lowly expressed in OVC cell lines, and overexpressing miR-636 significantly inhibited HO-8910PM cell proliferation, migration and induced cell cycle arrest in G0/G1 phase, while the inhibition of miR-636 caused opposite results. Dual-luciferase reporter gene assay revealed that Gli2 was the target gene of miR-636 in OVC. Besides, overexpressed miR-636 decreased protein expression of Gli2, and affected the expression of proteins related to the Hh signaling pathway and EMT. Rescue experiments verified that overexpression of Gli2 reversed the inhibitory effect of miR-636 on HO-8910PM cell proliferation and migration, and attenuated the blocking effect of miR-636 on cell cycle. The xenotransplantation experiment suggested that miR-636 inhibited cell growth of OVC by decreasing Gli2 expression. Besides, overexpressing Gli2 potentiated the EMT process of OVC cells via decreasing E-cadherin protein expression and increasing Vimentin protein expression, and it reversed the inhibitory effect of miR-636 on OVC cell proliferation in vivo.

Conclusion

miR-636 mediates the activation of the Hh pathway via binding to Gli2, thus inhibiting EMT, suppressing cell proliferation and migration of OVC.

Trial registration: The experimental protocol was established, according to the ethical guidelines of the Helsinki Declaration and was approved by the Human Ethics Committee of The Second Affiliated hospital of Zhejiang University School of Medicine (IR2019001235). Written informed consent was obtained from individual or guardian participants.

The PARP Inhibitor Olaparib Modulates the Transcriptional Regulatory Networks of Long Non-Coding RNAs during Vasculogenic Mimicry

In highly metastatic tumors, vasculogenic mimicry (VM) involves the acquisition by tumor cells of endothelial-like traits. Poly-(ADP-ribose) polymerase (PARP) inhibitors are currently used against tumors displaying BRCA1/2-dependent deficient homologous recombination, and they may have antimetastatic activity. Long non-coding RNAs (lncRNAs) are emerging as key species-specific regulators of cellular and disease processes. To evaluate the impact of olaparib treatment in the context of non-coding RNA, we have analyzed the expression of lncRNA after performing unbiased whole-transcriptome profiling of human uveal melanoma cells cultured to form VM. RNAseq revealed that the non-coding transcriptomic landscape differed between olaparib-treated and non-treated cells: olaparib significantly modulated the expression of 20 lncRNAs, 11 lncRNAs being upregulated, and 9 downregulated. We subjected the data to different bioinformatics tools and analysis in public databases. We found that copy-number variation alterations in some olaparib-modulated lncRNAs had a statistically significant correlation with alterations in some key tumor suppressor genes. Furthermore, the lncRNAs that were modulated by olaparib appeared to be regulated by common transcription factors: ETS1 had high-score binding sites in the promoters of all olaparib upregulated lncRNAs, while MZF1, RHOXF1 and NR2C2 had high-score binding sites in the promoters of all olaparib downregulated lncRNAs. Finally, we predicted that olaparib-modulated lncRNAs could further regulate several transcription factors and their subsequent target genes in melanoma, suggesting that olaparib may trigger a major shift in gene expression mediated by the regulation lncRNA. Globally, olaparib changed the lncRNA expression landscape during VM affecting angiogenesis-related genes.

Exostosin1 as a novel prognostic and predictive biomarker for squamous cell lung carcinoma: A study based on bioinformatics analysis

The exostosin (EXT) protein family is involved in diverse human diseases. However, the expression and prognostic value of EXT genes in human lung squamous cell carcinoma (LUSC) is not well understood. In this study, we analyzed the association between expression of EXT1 and EXT2 genes and survival in patients with LUSC using bioinformatics resources such as Oncomine and The Cancer Genome Atlas (TCGA) databases, the Gene Expression Profiling Interactive Analysis (GEPIA) server and Kaplan–Meier plotter. Furthermore, regulatory microRNAs (miRNAs) were predicted for EXT1 and used to establish a potential miRNA‐messenger RNA (mRNA) regulation network for LUSC using the ENCORI platform. We observed that EXT1 and EXT2 expression levels were higher in LUSC than those in normal tissues. However, only EXT1 expression was significantly associated with poor overall survival (OS) in LUSC patients. Functional annotation enrichment analysis showed that genes co‐expressed with the EXT1 gene were enriched in biological processes such as cell adhesion and migration, and KEGG pathways such as extracellular matrix receptor interactions, complement and coagulation cascades, and cell death. Furthermore, three miRNAs, hsa‐mir‐190a‐5p, hsa‐mir‐195‐5p, and hsa‐mir‐490‐3p, were identified to be potentially involved in the regulation of EXT1. In summary, we identified EXT1 expression as a novel potential prognostic marker for human LUSC and the regulatory miRNAs that could possibly contribute to the prognosis of the disease.

MBD2 and EZH2 regulate the expression of SFRP1 without affecting its methylation status in a colorectal cancer cell line

Secreted frizzled-related protein 1 (SFRP1), which is an extracellular inhibitor involved in Wnt signalling, is downregulated by promoter hypermethylation in the early stages of colorectal tumorigenesis. Polycomb (PCG) and methyl-CpG-binding domain (MBD) proteins that serve a role in epigenetic gene regulation. The aim of the present study was to determine the role of PCG and MBD proteins in the regulation of SFRP1 gene expression in colorectal cancer (CRC), specifically in CRC cell lines and the human embryo intestinal mucosa cell line CCC-HIE-2. The methylation status of the SFRP1 gene promoter were analysed using methylation-specific PCR (MSP), whereas SFRP1 mRNA expression was analysed using reverse transcription-quantitative PCR. The association between PCG and MBD proteins and the SFRP1 gene was assessed, where associated proteins were screened by chromatin immunoprecipitation and their expression were subsequently knocked down using RNA interference to determine their role in the regulation of SFRP1 gene expression. The SFRP1 promoter was demonstrated to be hypermethylated in CRC cell lines and partially methylated in the non-cancerous cell line CCC-HIE-2. SFRP1 mRNA expression was significantly lower in CRC cell lines compared with that of CCC-HIE-2 cells. The expression of PCGs enhancer of zeste homolog 2 (EZH2) and BMI1, along with MBD2, was indicated to be upregulated with SFRP1 methylation in HCT116 and SW480 cells. The SFRP1 promoter region was enriched with EZH2 in CCC-HIE-2 cells and enriched with EZH2 and MBD2 in SW480 cells, whereas none of the proteins examined were indicated on the SFRP1 promoter in HCT116 cells. The expression of SFRP1 was reactivated by MBD2 small interfering (si)RNA but not by EZH2 siRNA in SW480 cells, but combined MBD2 and EZH2 knockdown effectively restored SFRP1 gene expression without affecting the methylation status of the SFRP1 promoter. In conclusion, data from the present study revealed that MBD2 and EZH2 regulated SFRP1 expression without affecting the hypermethylation of SFRP1 in CRC cell lines. Instead, the regulation of SFRP1 expression may be through a distinct mechanism, which warrants further investigation.

Regulation of microRNA-497 expression in human cancer

MicroRNAs (miRNAs/miRs) are a type of non-coding single-stranded RNA, with a length of ~22 nt, which are encoded by endogenous genes and are involved in the post-transcriptional regulation of gene expression in animals and plants. Studies have demonstrated that miRNAs play an important role in the occurrence, development, metastasis, diagnosis and treatment of cancer. In recent years, miR-497 has been identified as one of the key miRNAs in a variety of cancer types and has been shown to be downregulated in a variety of solid tumors. However, the regulation of miR-497 expression involves a complex network, which is affected by several factors. The aim of the present review was to summarize the mechanism of regulation of miR-497 expression at the pre-transcriptional and transcriptional levels in cancer, as well as the role of miR-497 expression imbalance in cancer diagnosis, treatment and prognosis. The regulatory mechanisms of miR-497 expression may aid in our understanding of the causes of miR-497 expression imbalance and provide a reference value for further research on the diagnosis and treatment of cancer.

Biomarker Discovery for the Carcinogenic Heterogeneity Between Colon and Rectal Cancers Based on lncRNA-Associated ceRNA Network Analysis

Background

Colorectal cancer (CRC) is one of the leading causes of cancer death worldwide. Emerging evidence has revealed that risk factors and metastatic patterns differ greatly between colon and rectal cancers. However, the molecular mechanism underlying their pathogenic differences remains unclear. Therefore, we here aimed to identify non-coding RNA biomarkers based on lncRNA-associated ceRNA network (LceNET) to elucidate the carcinogenic heterogeneity between colon and rectal cancers.

Methods

A global LceNET in human was constructed by employing experimental evidence-based miRNA-mRNA and miRNA-lncRNA interactions. Then, four context-specific ceRNA networks related to cancer initiation and metastasis were extracted by mapping differentially expressed lncRNAs, miRNAs and mRNAs to the global LceNET. Notably, a novel network-based bioinformatics model was proposed and applied to identify lncRNA/miRNA biomarkers and critical ceRNA triplets for understanding the carcinogenic heterogeneity between colon and rectal cancers. Moreover, the identified biomarkers were further validated by their diagnostic/prognostic performance, expression pattern and correlation analysis.

Results

Based on network modeling, lncRNA KCNQ1OT1 (AUC>0.85) and SNHG1 (AUC>0.94) were unveiled as common diagnostic biomarkers for the initiation and metastasis of colon and rectal cancers. qRT-PCR analysis uncovered that these lncRNAs had significantly higher expression level in CRC cell lines with high metastatic potential. In particular, KCNQ1OT1 and SNHG1 function in colon and rectal cancers via different ceRNA mechanisms. For example, KCNQ1OT1/miR-484/ANKRD36 axis was involved in the initiation of colon cancer, while KCNQ1OT1/miR-181a-5p/PCGF2 axis was implicated in the metastasis of rectal cancer; the SNHG1/miR-484/ORC6 axis played a role in colon cancer, while SNHG1/miR-423-5p/EZH2 and SNHG1/let-7b-5p/ATP6V1F axes participated in the initiation and metastasis of rectal cancer, respectively. In these ceRNA triplets, miR-484, miR-181a-5p, miR-423-5p and let-7b-5p were identified as miRNA biomarkers with excellent distinguishing ability between normal and tumor tissues, and ANKRD36, PCGF2, EZH2 and ATP6V1F were closely related to the prognosis of corresponding cancer.

Conclusion

The landscape of lncRNA-associated ceRNA network not only facilitates the exploration of non-coding RNA biomarkers, but also provides deep insights into the oncogenetic heterogeneity between colon and rectal cancers, thereby contributing to the optimization of diagnostic and therapeutic strategies of CRC.

An in silico approach to identify and prioritize miRNAs target sites polymorphisms in colorectal cancer and obesity

Colorectal cancer (CRC) and obesity are linked clinical entities with a series of complex processes being engaged in their development. MicroRNAs (miRNAs) participate in these processes through regulating CRC and obesity‐related genes. This study aimed to develop an in silico approach to systematically identify and prioritize miRNAs target sites polymorphisms in obesity and CRC. Data from genome‐wide association studies (GWASs) were used to retrieve CRC and obesity‐associated variants. The polymorphisms that were resided in experimentally verified or computationally predicted miRNA target sites were retrieved and prioritized using a range of bioinformatics analyses. We found 6284 CRC and 38931 obesity unique variants. For CRC 33 haplotypes variants in 134 interactions were in miRNA targetome, while for obesity we found more than 935 unique interactions. Functionally prioritized SNPs revealed that, SNPs in 153 obesity and 50 CRC unique interactions were have disruptive effects on miRNA:mRNA integration by changing on target RNA secondary structure. Structural accessibility of target sites were decreased in 418 and 103 unique interactions and increased in 516 and 79 interactions, for obesity and CRC, respectively. The miRNA:mRNA hybrid stability was increased in 127 and 17 unique interactions and decreased in 33 and 24 interactions for the effect of obesity and CRC SNPs, respectively. In this study, seven SNPs with 15 interactions and three SNPs with four interactions were prioritized for obesity and CRC, respectively. These SNPs could be used for future studies for finding potential biomarkers for diagnoses, prognosis, or treatment of CRC and obesity.

Involvement of the lncRNA AFAP1-AS1/microRNA-195/E2F3 axis in proliferation and migration of enteric neural crest stem cells of Hirschsprung's disease

NEW FINDINGS

What is the central question of this study? Long non-coding RNAs (lncRNAs) are widely involved in the progression of Hirschsprung's disease (HSCR), but the role of actin filament associated protein 1 antisense RNA1 (AFAP1-AS1), an lncRNA, in HSCR has not been explored before. What is the main finding and its importance? Downregulation of AFAP1-AS1 blocks enteric neural crest stem cell proliferation, differentiation, migration and invasion and promotes the occurrence of HSCR via the miR-195/E2F3 axis, indicating thatAFAP1-AS might be a potential biomarker for HSCR patients.

ABSTRACT

Long non-coding RNAs (lncRNAs) are involved in several human disorders. Nevertheless, it remains unclear whether they are implicated in the phenotypes of enteric neural crest stem cells (ENCSCs) in Hirschsprung's disease (HSCR). Therefore, we designed this study to explore the pathogenicity of AFAP1-AS1 for HSCR. Microarray analysis and bioinformatic tools were used to screen out the differentially lncRNAs and microRNAs (miRNAs) in patients with HSCR. Small interference RNA transfection was applied to carry out functional experiments in ENCSCs. Cellular activities were detected by cell counting kit-8, 5-ethynyl-2'-deoxyuridine, Transwell assays and flow cytometry. Finally, rescue experiments were performed to examine the cofunction of AFAP1-AS1 and miR-195 and of miR-195 and E2F transcription factor 3 (E2F3). AFAP1-AS1 was reduced in HSCR patients. Meanwhile, knockdown of AFAP1-AS1 reduced the cell migratory and proliferative capacities and facilitated cell apoptosis along with G0/G1 phase arrest. E2F3 was diminished when miR-195 was upregulated, and AFAP1-AS1 inhibition reduced its ability to bind to miR-195. Altogether, AFAP1-AS1 silencing acts as an endogenous RNA by interacting with miR-195 to alter E2F3 expression, thus conferring repressive effects on ENCSC activity and promoting HSCR progression.

LncRNA DLX6-AS1 aggravates the development of ovarian cancer via modulating FHL2 by sponging miR-195-5p

Background

Ovarian cancer (OC) is a huge burden on women’s lives. Recently, the implication of long non-coding RNAs (lncRNAs) in cancers, including OC, has aroused much attention. The objective of this study was to explore the role and functional mechanism of lncRNA distal-less homeobox 6 antisense 1 (DLX6-AS1) in OC.

Methods

The expression of DLX6-AS1, miR-195-5p, and four and a half LIM domains protein 2 (FHL2) was measured by quantitative real-time polymerase chain reaction (qRT-PCR). The cell proliferation, apoptosis, migration, and invasion were assessed by cell count kit 8 (CCK-8), flow cytometry and transwell assays, respectively. The protein levels of proliferating cell nuclear antigen (PCNA), cleaved-caspase-3 (C-caspase 3), N-cadherin, Vimentin, E-cadherin and FHL2 were quantified by western blot. The relationship between miR-195-5p and DLX6-AS1 or FHL2 was predicted by bioinformatics tool starBase and verified by luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Xenograft tumor model was established to observe the role of DLX6-AS1 in vivo.

Results

DLX6-AS1 and FHL2 were up-regulated in OC tissues and cells, while miR-195-5p was down-regulated. DLX6-AS1 knockdown inhibited proliferation, migration, and invasion but induced apoptosis of OC cells. However, miR-195-5p inhibition reversed these effects. Overexpression of miR-195-5p also depleted proliferation, migration, and invasion but promoted apoptosis of OC cells, while FHL2 overexpression overturned these influences. DLX6-AS1 knockdown blocked tumor growth in vivo.

Conclusion

DLX6-AS1, as an oncogene in OC, accelerated tumor progression by up-regulating FHL2 via mediating miR-195-5p, suggesting that DLX6-AS1 was a hopeful target for the lncRNA-targeted therapy in OC.

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.

miRNA Clusters with Down-Regulated Expression in Human Colorectal Cancer and Their Regulation

Regulation of microRNA (miRNA) expression has been extensively studied with respect to colorectal cancer (CRC), since CRC is one of the leading causes of cancer mortality worldwide. Transcriptional control of miRNAs creating clusters can be, to some extent, estimated from cluster position on a chromosome. Levels of miRNAs are also controlled by miRNAs "sponging" by long non-coding RNAs (ncRNAs). Both types of miRNA regulation strongly influence their function. We focused on clusters of miRNAs found to be down-regulated in CRC, containing miR-1, let-7, miR-15, miR-16, miR-99, miR-100, miR-125, miR-133, miR-143, miR-145, miR-192, miR-194, miR-195, miR-206, miR-215, miR-302, miR-367 and miR-497 and analysed their genome position, regulation and functions. Only evidence provided with the use of CRC in vivo and/or in vitro models was taken into consideration. Comprehensive research revealed that down-regulated miRNA clusters in CRC are mostly located in a gene intron and, in a majority of cases, miRNA clusters possess cluster-specific transcriptional regulation. For all selected clusters, regulation mediated by long ncRNA was experimentally demonstrated in CRC, at least in one cluster member. Oncostatic functions were predominantly linked with the reviewed miRNAs, and their high expression was usually associated with better survival. These findings implicate the potential of down-regulated clusters in CRC to become promising multi-targets for therapeutic manipulation.

Multi-omics analysis to identify driving factors in colorectal cancer

Aim: We aim to identify driving genes of colorectal cancer (CRC) through multi-omics analysis. Materials & methods: We downloaded multi-omics data of CRC from The Cancer Genome Atlas dataset. Integrative analysis of single-nucleotide variants, copy number variations, DNA methylation and differentially expressed genes identified candidate genes that carry CRC risk. Kernal genes were extracted from the weighted gene co-expression network analysis. A competing endogenous RNA network composed of CRC-related genes was constructed. Biological roles of genes were further investigated in vitro. Results: We identified LRRC26 and REP15 as novel prognosis-related driving genes for CRC. LRRC26 hindered tumorigenesis of CRC in vitro. Conclusion: Our study identified novel driving genes and may provide new insights into the molecular mechanisms of CRC.

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.

Can small nucleolar RNA be a novel molecular target for hepatocellular carcinoma?

BACKGROUND

Globally, hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death. Recently, many studies have demonstrated that small nucleolar RNA (snoRNA) was closely related to HCC.

OBJECTIVE

To explore whether snoRNA can be used as a molecular target for HCC.

METHODS

The PubMed, Embase, and Cochrane databases were searched for the published literatures related to snoRNA and HCC until August 12, 2019. After identification, screening, and verification, this study finally included 26 studies correlating small nucleolar RNA host gene (SNHG) and HCC, and 8 studies correlating snoRNA and HCC. Based on the collation of the relevant literature, the correlation network diagram between snoRNAs and HCC was constructed.

RESULTS

The SNHGs, such as SNHG1, SNHG6, SNHG16, and SNHG20 can play varied roles in HCC through different regulatory mechanisms. These SNHGs can promote and inhibit tumorigenesis. SNORD76 can promote the proliferation of tumor tissues and cells in vitro through different pathways. SnoU2_19 and SNORD76 can function through the same pathway. SNHG3, SNHG20, SNHG6, SNORD76, and snoRA47 can modulate epithelial-mesenchymal transition (EMT) to regulate the development of HCC cell or tissue. SNHG16, SNORD76, and SnoU2_19 can regulate the development of HCC through Wnt/β-catenin signaling pathway.

CONCLUSION

snoRNA can regulate the occurrence of HCC by modulating multiple molecular signaling pathways. Hence, snoRNA can be a potential molecular target for HCC.

KCNQ1OT1 aggravates cell proliferation and migration in bladder cancer through modulating miR-145-5p/PCBP2 axis

Background

The large involvement of long non-coding RNAs (LncRNAs) in the biological progression of numerous cancers has been reported. The function of lncRNA KCNQ1OT1 in bladder cancer (BC) remains largely unknown. This study aimed to explore the critical role of KCNQ1OT1 in BC.

Materials and methods

The qRT-PCR was applied to test the expression of RNAs. Cell proliferation was detected by CCK-8 and colony formation assays. Cell apoptosis was measured by TUNEL and flow cytometry experiments. Wound healing and transwell assays were employed to evaluate cell migration and invasion ability respectively. Western blot assay was used to measure relevant protein expression. Immunofluorescence (IF) staining was used to observe EMT process in BC.

Results

KCNQ1OT1 was significantly overexpressed in BC tissue and cell lines. KCNQ1OT1 depletion repressed cell proliferation, migration and invasion, whereas encouraged cell apoptosis. KCNQ1OT1 was a negatively/positively correlated with miR-145-5p/PCBP2 in respect with expression. Mechanically, KCNQ1OT1 was sponge of miR-145-5p and up-regulated the expression of PCBP2. MiR-145-5p inhibition and PCBP2 up-regulation could countervail the tumor-inhibitor role of KCNQ1OT1 knockdown in BC.

Conclusion

KCNQ1OT1 serves as competing endogenous RNA (ceRNA) to up-regulate PCBP2 via sponging miR-145-5p in BC progression.

Long non-coding small nucleolar RNA host genes in digestive cancers

Although long noncoding RNAs (lncRNAs) do not have protein coding capacities, they are involved in the pathogenesis of many types of cancers, including hepatocellular carcinoma, cervical cancer, and gastric cancer. Notably, the roles of lncRNAs are vital in nearly every aspect of tumor biology. Long non-coding small nucleolar RNA host genes (lnc-SNHGs) are abnormally expressed in multiple cancers, including urologic neoplasms, respiratory tumors, and digestive cancers, and play vital roles in these cancers. These host genes could participate in tumorigenesis by regulating proliferation, migration, invasion and apoptosis of tumor cells. This review focuses on the overview of the roles that lnc-SNHGs play in the formation and progression of digestive cancers.

ZEB2-AS1 Accelerates Epithelial/Mesenchymal Transition Through miR-1205/CRKL Pathway in Colorectal Cancer

Background: Accumulating reports have demonstrated that long-noncoding RNAs (lncRNAs) play critical roles in the pathological progression of colorectal cancer (CRC). However, the role of lncRNA zinc finger E-box binding homeobox 2 antisense RNA 1 (ZEB2-AS1) in CRC remains largely unknown. Methods: The authors detected the ZEB2-AS1 expression in CRC tissue sample and CRC cell lines. The effects of ZEB2-AS1 on CRC were identified through in vitro assays (i.e., transwell assay, wound-healing assay, immunofluorescence assay, and Western blot) in a ZEB2-AS1 knockdown system. The molecular mechanism of ZEB2-AS1 was explored via bioinformatic tools, quantitative real-time polymerase chain reaction (qRT-PCR), dual-luciferase reporter assay, RNA immunoprecipitation assay, and so on. Moreover, a series of gain-of-function experiments were performed to identify the effect of ZEB2-AS1 and miR-1205 on epithelial-to-mesenchymal transition (EMT) in CRC cells. Results: This analysis clarified that ZEB2-AS1 was upregulated in both CRC tissue sample and cells lines; meanwhile, the high expression of ZEB2-AS1 was correlated with poor overall survival rate. ZEB2-AS1 knockdown significantly suppresses the EMT in CRC cells. Furthermore, the authors identified that the expression of ZEB2-AS1 was negatively correlated with expression of miR-1205, and CRKL could be a direct target of miR-1205. Through the gain-of-function experiments, they found that ZEB2-AS1 accelerates EMT in CRC cells via modulating the expression of miR-1205 and CRKL. Conclusion: Taken together, this study revealed that ZEB2-AS1 accelerates EMT in CRC through the miR-1205/CRKL pathway, suggesting that ZEB2-AS1 may potentially serve as a target of CRC.