Long Non-Coding RNA Cancer Susceptibility 9 (CASC9) Up-Regulates the Expression of ERBB2 by Inhibiting miR-193a-5p in Colorectal Cancer

Four differentially expressed exosomal miRNAs as prognostic biomarkers and therapy targets in endometrial cancer: Bioinformatic analysis

Endometrial cancer (EC) is one of the most common gynecological malignancies worldwide. Accumulated evidence has demonstrated exosomes of cancer cells carry microRNAs (miRNAs) to nonmalignant cells to induce metastasis. Our study aimed to find possible biomarkers of EC. Data for miRNA expression related with exosome from EC patients were downloaded from The Cancer Genome Atlas database, and the miRNA expression profiles associated with exosomes of EC were downloaded from the National Center for Biotechnology Information. We used different algorithms to analyze the differential miRNA expression, infer the relative proportion of immune infiltrating cells, predict chemotherapy sensitivity, and comprehensively score each gene set to evaluate the potential biological function changes of different samples. The gene ontology analysis and Kyoto encyclopedia of genome genomics pathway analysis were performed for specific genes. A total of 13 differential miRNAs were identified, of which 4 were up-regulated. The 4 miRNAs, that is hsa-miR-17-3p, hsa-miR-99b-3p, hsa-miR-193a-5p, and hsa-miR-320d, were the hub exosomal miRNAs that were all closely related to the clinic phenotypes and prognosis of patients. This study preliminarily indicates that the 4 hub exosomal miRNAs (hsa-miR-17-3p, hsa-miR-99b-3p, hsa-miR-193a-5p, and hsa-miR-320d) could be used as prognostic biomarkers or therapy targets in EC. Further studies are required to make sure of their real feasibility and values in the EC clinic and the relative research.

Long Non-coding RNA LINC01224 Promotes the Malignant Behaviors of Triple Negative Breast Cancer Cells via Regulating the miR-193a-5p/NUP210 Axis

Triple negative breast cancer (TNBC) is a prevalent malignant tumor in women and is characterized by high incidence and mortality. Current evidence has suggested that multiple long noncoding RNAs (lncRNAs) play regulatory roles in TNBC, while the specific mechanism of LINC01224 in TNBC remains unclear. In this study, LINC01224 was highly expressed in TNBC cells. Moreover, LINC01224 downregulation inhibited TNBC cell proliferation, migration, and invasion, and promoted cell apoptosis. Additionally, LINC01224 stabilized NUP210 mRNA through interaction with miR-193a-5p, thereby aggravating the malignant phenotypes of TNBC. Overall, LINC01224 functions as a tumor promoter for TNBC.

Long Noncoding RNAs in the Prediction of Survival of Patients with Digestive Cancers

BACKGROUND

Long noncoding RNAs have been known to be involved in various cancers. This study aimed to find a long noncoding RNA signature to predict the prognostic risk of patients with digestive cancers, including esophageal carcinoma, stomach adenocarcinoma, liver hepatocellular carcinoma, and pancreatic adenocarcinoma.

METHODS

After screening differentially expressed long noncoding RNAs in 4 digestive cancers from The Cancer Genome Atlas database, the prognostic significance of the above differentially expressed long noncoding RNAs was evaluated by Kaplan-Meier analysis. Target genes of the corresponding differentially expressed long noncoding RNAs were predicted by StarBase. We performed bioinformatics methods, including gene ontology annotation and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis, to explore the role and molecular mechanisms of differentially expressed long noncoding RNAs and predicted target genes in tumor progression.

RESULTS

A total of 4 differentially expressed long noncoding RNAs (AC093895.1, CASC9, LINC01980, and HOXC-AS2) with a significant prognostic value were identified. Moreover, 6 target genes were obtained. Also, functional enrichment analysis showed that these 4 DELs were mainly related to the regulation of mRNA metabolic process, regulation of RNA stability, mRNA binding, RNA localization, and spliceosome.

CONCLUSION

The prognostic differentially expressed long noncoding RNAs and target genes in the digestive cancers were obtained, which may provide a novel direction for treatment and prognosis improvement of digestive cancers.

Construction of a prognostic model of colon cancer patients based on metabolism-related lncRNAs

Background

Many studies have shown that metabolism-related lncRNAs may play an important role in the pathogenesis of colon cancer. In this study, a prognostic model for colon cancer patients was constructed based on metabolism-related lncRNAs.

Methods

Both transcriptome data and clinical data of colon cancer patients were downloaded from the TCGA database, and metabolism-related genes were downloaded from the GSEA database. Through differential expression analysis and Pearson correlation analysis, long non-coding RNAs (lncRNAs) related to colon cancer metabolism were obtained. CRC patients were divided into training set and verification set at the ratio of 2:1. Based on the training set, univariate Cox regression analysis was utilized to determine the prognostic differential expression of metabolic-related lncRNAs. The Optimal lncRNAs were obtain by Lasso regression analysis, and a risk model was built to predict the prognosis of CRC patients. Meanwhile, patients were divided into high-risk and low-risk groups and a survival curve was drawn accordingly to determine whether the survival rate differs between the two groups. At the same time, subgroup analysis evaluated the predictive performance of the model. We combined clinical indicators with independent prognostic significance and risk scores to construct a nomogram. C index and the calibration curve, DCA clinical decision curve and ROC curve were obtained as well. The above results were all verified using the validation set. Finally, based on the CIBERSORT analysis method, the correlation between lncRNAs and 22 tumor-infiltrated lymphocytes was explored.

Results

By difference analysis, 2491 differential lncRNAs were obtained, of which 226 were metabolic-related lncRNAs. Based on Cox regression analysis and Lasso results, a multi-factor prognostic risk prediction model with 13 lncRNAs was constructed. Survival curve results suggested that patients with high scores and have a poorer prognosis than patients with low scores (P<0.05). The area under the ROC curve (AUC) for the 3-year survival and 5-year survival were 0.768 and 0.735, respectively. Cox regression analysis showed that age, distant metastasis and risk scores can be used as independent prognostic factors. Then, a nomogram including age, distant metastasis and risk scores was built. The C index was 0.743, and the ROC curve was drawn to obtain the AUC of the 3-year survival and the 5-year survival, which were 0.802 and 0.832, respectively. The above results indicated that the nomogram has a good predictive effect. Enrichment analysis of KEGG pathway revealed that differential lncRNAs may be related to chemokines, amino acid and sugar metabolism, NOD-like receptor and Toll-like receptor activation as well as other pathways. Finally, the analysis results based on the CIBERSORT algorithm showed that the lncRNAs used to construct the model had a strong polarized correlation with B cells, CD8+T cells and M0 macrophages.

Conclusion

13 metabolic-related lncRNAs affecting the prognosis of CRC were screened by bioinformatics methods, and a prognostic risk model was constructed, laying a solid foundation for the research of metabolic-related lncRNAs in CRC.

Regulatory effects of lncRNAs and miRNAs on the crosstalk between autophagy and EMT in cancer: a new era for cancer treatment

PURPOSE

Autophagy and EMT (epithelial-mesenchymal transition) are the two principal biological processes and ideal therapeutic targets during cancer development. Autophagy, a highly conserved process for degrading dysfunctional cellular components, plays a dual role in tumors depending on the tumor stage and tissue types. The EMT process is the transition differentiation from an epithelial cell to a mesenchymal-like cell and acquiring metastatic potential. There is evidence that the crosstalk between autophagy and EMT is complex in cancer. In recent years, more studies have shown that long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) are involved in autophagy, EMT, and their crosstalk. Therefore, accurate understanding of the regulatory mechanisms of lncRNAs and miRNAs in autophagy, EMT and their interactions is crucial for the clinical management of cancers.

METHODS

An extensive literature search was conducted on the Google Scholar and PubMed databases. The keywords used for the search included: autophagy, EMT, crosstalk, lncRNAs, miRNAs, cancers, diagnostic biomarkers, and therapeutic targets. This search provided relevant articles published in peer-reviewed journals until 2021. Data from these various studies were extracted and used in this review.

RESULTS

The results showed that lncRNAs/miRNAs as tumor inhibitors or tumor inducers could regulate autophagy, EMT, and their interaction by regulating several molecular signaling pathways. The lncRNAs/miRNAs involved in autophagy and EMT processes could have potential uses in cancer diagnosis, prognosis, and therapy.

CONCLUSION

Such information could help find and develop lncRNAs/miRNAs based new tools for diagnosing, prognosis, and creating anti-cancer therapies.

Cancer Susceptibility Candidate 9 (CASC9) Promotes Colorectal Cancer Carcinogenesis via mTOR-Dependent Autophagy and Epithelial-Mesenchymal Transition Pathways

BACKGROUND

Colorectal cancer (CRC) is the third most common cancer worldwide. Many recent studies have demonstrated that different long non-coding RNAs (lncRNAs) are involved in the initiation, advancement, and metastasis of many cancers including CRC. Cancer susceptibility candidate 9 (CASC9) is an lncRNA that has been reported in many cancers, but its role in CRC is poorly understood. In this study, we aimed to examine the expression of CASC9 in CRC cell lines and to determine the mechanism of action of CASC9 in CRC carcinogenesis.

METHODS

The expression of CASC9 in CRC tissues was compared with normal samples from publicly available datasets in The Cancer Genome Atlas (TCGA) and The Encyclopedia of RNA Interactomes (ENCORI). CASC9 expression was further verified in four CRC cell lines (DLD1, HT-29, SW480, and HCT-116) and normal colorectal cell line (CCD-112CoN) by real-time quantitative polymerase chain reaction (RT-qPCR). After gene silencing in HCT-116 and SW480, Cell Counting Kit-8 assay, clonogenic assay, and wound healing assay were performed to evaluate cell proliferation, viability, and migration index of cells. Western blotting was used to explore the key pathways involved.

RESULTS

CASC9 was significantly upregulated as analyzed from both public datasets TCGA and ENCORI where its overexpression was associated with poor survival of CRC patients. Similarly, CASC9 was significantly overexpressed in the CRC cell lines compared with normal cells studied. The silencing of CASC9 in HCT-116 and SW480 attenuated cell proliferation and migration significantly. Furthermore, pathways investigations showed that silencing of CASC9 significantly induced autophagy, promoted AMP-activated protein kinase (AMPK) phosphorylation, inhibited mTOR and AKT signaling pathways, and altered epithelial-mesenchymal transition (EMT) marker protein expression.

CONCLUSION

We demonstrated that silencing of CASC9 contributes to the reduced CRC cell proliferation and migration by regulating autophagy and AKT/mTOR/EMT signaling. Therefore, CASC9 plays an important role in carcinogenesis, and its expression may act as a prognostic biomarker and a potential therapeutic target of CRC management.

Long noncoding RNA DUXAP10 promotes the stemness of glioma cells by recruiting HuR to enhance Sox12 mRNA stability

Long noncoding RNA (lncRNA) DUXAP10 has been shown to act as an oncogene in various tumors; however, its roles in glioma progression have never been established. Here, we show that DUXAP10 is overexpressed in glioma tissues and cells. Loss of function experiments reveal that DUXAP10 knockdown has little effects on glioma cell viability, but significantly reduces the stemness of glioma cells, which is characterized as the decrease of stemness marker expression, tumor sphere-forming ability, and ALDH activity. RNA immunoprecipitation and immunofluorescence assays indicate that DUXAP10 can directly interact with HuR protein and suppress the cytoplasm-nuclear translocation of HuR, which subsequently enhances Sox12 mRNA stability in cytoplasm and thus increases Sox12 expression. Further rescuing experiments show that the HuR/Sox12 axis is responsible for DUXAP10-mediated effects on glioma cell stemness.

Long noncoding RNA MCM3AP-AS1 enhances cell proliferation and metastasis in colorectal cancer by regulating miR-193a-5p/SENP1

BACKGROUND

Accumulating evidences have shown that long noncoding RNAs (lncRNAs) play key roles in many diseases, including cancer. Several studies reported that MCM3AP antisense RNA 1 (MCM3AP-AS1) was associated with the tumorigenesis and progression. However, the specific function and mechanism of MCM3AP-AS1 in colorectal cancer (CRC) have not been fully understood.

METHODS

The expression of MCM3AP-AS1 was detected by quantitative reverse transcription PCR (RT-qPCR) in CRC tissues and matched noncancerous tissues (NCTs). CCK-8 assay, colony formation assay, transwell assay, xenograft and lung metastasis mouse models were used to examine the tumor-promoting function of MCM3AP-AS1 in vitro and in vivo. The binding relationship between MCM3AP-AS1, miR-193a-5p and sentrin-specific peptidase 1 (SENP1) were screened and identified by databases, RT-qPCR, dual luciferase reporter assay and western blot.

RESULTS

In the present study, we got that the expression of MCM3AP-AS1 was higher in CRC tissues than in paired NCTs, and increased MCM3AP-AS1 expression was associated with adverse outcomes in CRC patients. Functional experiments in vitro revealed that silencing of MCM3AP-AS1 could inhibit the proliferation, colony formation, migratory, and invasive abilities of CRC cells. The mouse models of xenograft and lung metastasis further confirmed that in vivo silencing MCM3AP-AS1 could significantly inhibit the growth and metastasis of CRC. Further mechanism studies indicated that MCM3AP-AS1 could sponge miR-193a-5p and inhibit the activity of it. What is more, SENP1 was proved to be a novel target of miR-193a-5p and could be upregulated by MCM3AP-AS1. At last, we observed that SENP1 overexpression in CRC tissues was closely related to unfavorable prognosis.

CONCLUSION

Taken together, we identified in CRC the MCM3AP-AS1/miR-193a-5p/SENP1 regulatory axis, which affords a therapeutic possibility for CRC.

Crosstalk of long non-coding RNAs and EMT: Searching the missing pieces of an incomplete puzzle for lung cancer therapy

BACKGROUND

Lung cancer is considered to be the first place among the cancer-related deaths worldwide and demands novel strategies in the treatment of this life-threatening disorder. The aim of this review is to explore regulation of epithelial-to-mesenchymal transition (EMT) by long non-coding RNAs (lncRNAs) in lung cancer.

INTRODUCTION

LncRNAs can be considered as potential factors for targeting in cancer therapy, since they regulate a bunch of biological processes, e.g. cell proliferation, differentiation and apoptosis. The abnormal expression of lncRNAs occurs in different cancer cells. On the other hand, epithelial-to-mesenchymal transition (EMT) is a critical mechanism participating in migration and metastasis of cancer cells.

METHOD

Different databases including Googlescholar, Pubmed and Sciencedirect were used for collecting articles using keywords such as "LncRNA", "EMT", and "Lung cancer".

RESULT

There are tumor-suppressing lncRNAs that can suppress EMT and metastasis of lung cancer cells. Expression of such lncRNAs undergoes down-regulation in lung cancer progression and restoring their expression is of importance in suppressing lung cancer migration. There are tumor-promoting lncRNAs triggering EMT in lung cancer and enhancing their migration.

CONCLUSION

LncRNAs are potential regulators of EMT in lung cancer, and targeting them, both pharmacologically and genetically, can be of importance in controlling migration of lung cancer cells.

lncRNA MCM3AP-AS1 inhibits the progression of colorectal cancer via the miR-19a-3p/FOXF2 axis

BACKGROUND

Long non-coding RNA MCM3AP antisense RNA 1 (lncRNA MCM3AP-AS1) has a regulatory role in the development of diverse malignancies, whereas its role and mechanism in colorectal cancer (CRC) is not yet clear.

METHODS

The relative expression of MCM3AP-AS1, miR-19a-3p and forkhead box F2 (FOXF2) mRNA in 53 cases of CRC and its adjacent normal tissues, human normal colonic mucosal cells (FHC cells) and CRC cell lines was examined by a quantitative real-time polymerase chain reaction, and the changes of cell multiplication and migration were examined by the cell counting kit-8 method, EdU test, and scratch-healing test, respectively. Bioinformatics, dual-luciferase reporter gene assay and a RNA immunoprecipitation experiment were adopted to predict and verify the relationship between MCM3AP-AS1 and miR-19a-3p; bioinformatics and dual-luciferase reporter gene assay were adopted to predict and verify the relationship between miR-19a-3p and FOXF2. Western blotting was executed to examine the effects of MCM3AP-AS1 overexpression or knockdown on FOXF2 protein expression.

RESULTS

MCM3AP-AS1 expression was down-modulated in CRC, and its dysregulation was linked to unfavorable pathological characteristics. MCM3AP-AS1 significantly impeded the multiplication and migration of CRC cells. MCM3AP-AS1 was recognized as a molecular sponge to suppress miR-19a-3p expression, and FOXF2 was a target gene of miR-19a-3p. MCM3AP-AS1 positively modulated FOXF2 expression, and its biological effect was dependent the on miR-19a-3p/FOXF2 axis.

CONCLUSIONS

MCM3AP-AS1 can inhibit CRC promoting by modulating the miR-19a-3p/FOXF2 axis.

Long non-coding RNA CASC9 promotes gefitinib resistance in NSCLC by epigenetic repression of DUSP1

Resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), such as gefitinib, has greatly affected clinical outcomes in non-small cell lung cancer (NSCLC) patients. The long noncoding RNAs (lncRNAs) are known to regulate tumorigenesis and cancer progression, but their contributions to NSCLC gefitinib resistance remain poorly understood. In this study, by analyzing the differentially expressed lncRNAs in gefitinib-resistant cells and gefitinib-sensitive cells in the National Institute of Health GEO dataset, we found that lncRNA CASC9 expression was upregulated, and this was also verified in resistant tissues. Gain and loss of function studies showed that CASC9 inhibition restored gefitinib sensitivity both in vitro and in vivo, whereas CASC9 overexpression promoted gefitinib resistance. Mechanistically, CASC9 repressed the tumor suppressor DUSP1 by recruiting histone methyltransferase EZH2, thereby increasing the resistance to gefitinib. Furthermore, ectopic expression of DUSP1 increased gefitinib sensitivity by inactivating the ERK pathway. Our results highlight the essential role of CASC9 in gefitinib resistance, suggesting that the CASC9/EZH2/DUSP1 axis might be a novel target for overcoming EGFR-TKI resistance in NSCLC.

Long Non-Coding RNA LOXL1-AS1 Enhances Colorectal Cancer Proliferation, Migration and Invasion Through miR-708-5p/CD44-EGFR Axis

Introduction

Colorectal cancer (CRC), the third most common cancer worldwide, involves a physiological and pathological long non-coding RNA (lncRNA) paradigm shift. It has been reported that the lncRNA LOXL1-AS1 affects tumor development for many kinds of cancers, but its functions and mechanisms in CRC remain unknown.

Methods

Expression levels of LOXL1-AS1 and miR-708-5p within CRC tissues and cell lines were measured using qRT-PCR. The performance of gain-of-function and loss-of-function assays was aimed at examining the effects of LOXL1-AS1 and miR-708-5p; colony formation and cell viability assays were carried out to measure cell multiplication; and Transwell migration and wound-healing assays were carried out for the measurement of cell migration and invasion. Luciferase reporter assay was used to verify the interactions between LOXL1-AS1 and miR-708-5p and between miR-708-5p and the CD44-EGFR signaling pathway. Finally, expression of CD44 and EGFR proteins was measured by Western blot and immunofluorescence assays.

Results

In this study, we reveal that the regulation of lncRNA LOXL1-AS1 occurs within CRC based on the correlation with poor clinical outcomes. LOXL1-AS1 knockdown along with miR-708-5p overpresentation in CRC cell lines inhibited cell multiplication, migration, and invasion. The inhibiting effect of LOXL1-AS1 knockdown on CRC was reversed by upregulating the CD44-EGFR signal pathway. From the perspective of mechanism, LOXL1-AS1 imposes sponging upon miR-708-5p and thereby promotes the CD44-EGFR signal pathway in CRC cells.

Discussion

This study demonstrated that lncRNA LOXL1-AS1 enhances multiplication, migration, invasion, and progression of CRC by sponging miR-708-5p to regulate the CD44-EGFR signal pathway.

MAGI2-AS3 rs7783388 polymorphism contributes to colorectal cancer risk through altering the binding affinity of the transcription factor GR to the MAGI2-AS3 promoter

Background

It has been indicated that the single nuclear polymorphisms (SNPs) in the long noncoding RNA (lncRNA) have association with colorectal cancer (CRC) susceptibility.

Methods

We enrolled 1078 cases with CRC and 1175 age‐ and gender‐matched cancer‐free controls to explore whether the polymorphisms in MAGI2‐AS3 have associations with CRC risk. qRT‐PCR, expression quantitative trait loci (eQTL) analyses, dual‐luciferase reporter assay, chromatin immunoprecipitation (ChIP), flow cytometry, and transwell assays were performed to explore the specific mechanisms in which MAGI2‐AS3 rs7783388 variation influenced the tumorigenesis of CRC.

Results

Subjects carrying rs7783388 GG genotype presented a higher risk of CRC compared with the AG/AA genotypes. Mechanistically, we found that the functional genetic variant of rs7783388 A > G decreased binding affinity of transcription factor glucocorticoid receptor (GR) to the MAGI2‐AS3 promoter, resulting in decreased transcriptional activity that subsequently downregulated MAGI2‐AS3 expression. Furthermore, functional experiments elucidated that MAGI2‐AS3 overexpression suppressed CRC cell proliferation, migration, and invasion capacities, arrested cell cycle at G0/G1 phase, and promoted cell apoptosis.

Conclusion

Taken together, our study demonstrated that the potential function of MAGI2‐AS3 as a tumor suppressor for CRC, and the MAGI2‐AS3 rs7783388 polymorphism is associated with the increased susceptibility to CRC by altering the binding ability of GR to the MAGI2‐AS3 promoter.