LncRNA NEAT1 accelerates breast cancer progression through regulating miR-410-3p/ CCND1 axis

Long noncoding RNAs as regulators of epithelial mesenchymal transition in breast cancer: A recent review

AIMS

Breast cancer (BC) is the most frequently occurring cancer in women worldwide. BC patients are often diagnosed at advanced stages which are characterized by low survival rates. Distant metastasis is considered a leading cause of mortalities among BC patients. Epithelial-to-mesenchymal transition (EMT) is a transdifferentiation program that is necessary for cancer cells to acquire metastatic potential. In the last decade, long noncoding RNAs (lncRNAs) proved their significant contribution to different hallmarks of cancer, including EMT and metastasis. The primary aim of our review is to analyze recent studies concerning the molecular mechanisms of lncRNAs implicated in EMT regulation in BC.

MATERIALS AND METHODS

We adopted a comprehensive search on databases of PubMed, Web of Science, and Google Scholar using the following keywords: lncRNAs, EMT, breast cancer, and therapeutic targeting.

KEY FINDINGS

The different roles of lncRNAs in the mechanisms and signaling pathways governing EMT in BC were summarized. LncRNAs could induce or inhibit EMT through WNT/β-catenin, transforming growth factor-β (TGF-β), Notch, phosphoinositide 3-kinase/protein kinase B (PI3K/AKT), signal transducer and activator of transcription 3 (STAT3), and nuclear factor kappa B (NF-κB) pathways as well as via their interaction with histone modifying complexes and miRNAs.

SIGNIFICANCE

LncRNAs are key regulators of EMT and BC metastasis, presenting potential targets for therapeutic interventions. Further research is necessary to investigate the practical application of lncRNAs in clinical therapeutics.

Exosomal lncRNA NEAT1 induces paclitaxel resistance in breast cancer cells and promotes cell migration by targeting miR-133b

The lncRNA nuclear paraspeckle assembly transcript 1 (lncRNA NEAT1) has been associated with the development, metastasis and drug resistance of breast cancer (BC). However, the mechanisms underlying NEAT1-induced paclitaxel resistance in the microenvironment of BC remain unclear. In this study, NEAT1 expression was found to be high in paclitaxel-resistant BC cells (SKBR3/PR cells) and exosomes derived from these cells. NEAT1 promoted the migration of BC cells and their resistance to paclitaxel, whereas its downregulation reduced the drug resistance. In addition, downregulation of NEAT1 decreased the migration and proliferation of BC cells by inhibiting the expression of CXCL12 by reducing the adsorption of miR-133b. Furthermore, inhibition of miR-133b reversed the interference of NEAT1 and CXCL12 in paclitaxel resistance, migration and proliferation of BC cells. Knockdown of NEAT1 in a xenograft-bearing mouse model remarkably inhibited cancer progression and improved the response to paclitaxel. Altogether, this study revealed that SKBR3/PR cell-derived exosomal lncRNA NEAT1 can induce paclitaxel resistance and cell migration and growth in the tumour microenvironment of BC and may serve as a new target for the clinical treatment of BC.

Long non-coding RNA OIP5-AS1 inhibition upregulates microRNA-129-5p to repress resistance to temozolomide in glioblastoma cells via downregulating IGF2BP2

OBJECTIVE

Long non-coding RNAs (lncRNAs) and miRNAs (miRNAs) participate in tumors, while the effects of lncRNA OIP5 antisense RNA 1 (OIP5-AS1) and miR-129-5p on glioblastoma (GBM) remain to be further studied. We aim to explore the role of OIP5-AS1/miR-129-5p/insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) axis in GBM progression.

METHODS

OIP5-AS1, miR-129-5p and IGF2BP2 expression in tissues was determined. Temozolomide (TMZ)-resistant GBM cells were established and transfected with relative plasmid to alter OIP5-AS1, IGF2BP2 or miR-129-5p expression. Then, the viability, proliferation, apoptosis and in vivo tumor growth were assessed. The subcellular localization of OIP5-AS1 was determined, and the binding relationships between OIP5-AS1 and miR-129-5p, and between miR-129-5p and IGF2BP2 were confirmed.

RESULTS

OIP5-AS1 and IGF2BP2 were upregulated whereas miR-129-5p was downregulated in GBM. OIP5-AS1 silencing or miR-129-5p overexpression inhibited GBM cell chemoresistance to TMZ and proliferation, and promoted cell apoptosis. MiR-129-5p downregulation or IGF2BP2 upregulation reversed the role of OIP5-AS1 silencing on GBM cells. OIP5-AS1 sponged miR-129-5p and miR-129-5p targeted IGF2BP2.

CONCLUSION

OIP5-AS1 inhibition upregulated miR-129-5p to repress resistance to TMZ in GBM cells via downregulating IGF2BP2.

Molecular Interactions of the Long Noncoding RNA NEAT1 in Cancer

As one of the best-studied long noncoding RNAs, nuclear paraspeckle assembly transcript 1 (NEAT1) plays a pivotal role in the progression of cancers. NEAT1, especially its isoform NEAT1-1, facilitates the growth and metastasis of various cancers, excluding acute promyelocytic leukemia. NEAT1 can be elevated via transcriptional activation or stability alteration in cancers changing the aggressive phenotype of cancer cells. NEAT1 can also be secreted from other cells and be delivered to cancer cells through exosomes. Hence, elucidating the molecular interaction of NEAT1 may shed light on the future treatment of cancer. Herein, we review the molecular function of NEAT1 in cancer progression, and explain how NEAT1 interacts with RNAs, proteins, and DNA promoter regions to upregulate tumorigenic factors.

LncRNA NEAT1 Targets miR-342-3p/CUL4B to Inhibit the Proliferation of Cutaneous Squamous Cell Carcinoma Cells

Objective. This study investigated whether lncRNA NEAT1 could inhibit the proliferation of cutaneous squamous cell carcinoma (CSCC) cells by targeting miR-342-3p/CUL4B, thereby affecting the occurrence and development of CSCC. Methods. Fluorescence quantitative PCR was used to detect the expression of lncRNA NEAT1 and miR-42-3p in skin squamous cell carcinoma and adjacent tissues. Bioinformatics software and luciferase reporter gene assay were used to analyze the association of lncRNA NEAT1 and miR-342-3p. The effect of overexpression or knockdown of miR-342-3p on the proliferation of CSCC cells was examined by MTT and colony formation assays. Western blotting was used to detect the proteins of the miR-342-3p/CUL4B signaling axis. Results. The lncRNA NEAT1 is abnormally overexpressed in CSCC tissues and cell lines. The expression of lncRNA NEAT1 and miR-342-3p in CSCC was negatively correlated. Bioinformatics prediction analysis revealed that lncRNA NEAT1 regulates the expression of miR-342-3p. The results of MTT and plate colony formation experiments showed that the transfection of miR-342-3p mimics significantly inhibited the proliferation and plate colony formation of CSCC cells, while the transfection of miR-342-3p inhibitor significantly promoted the proliferation and plate colony-forming ability of CSCC cells. Western blot results showed that lncRNA NEAT1 affected CSCC cell proliferation through miR-342-3p/CUL4B/PI3K-Akt signaling pathway. Conclusion. The expression of lncRNA NEAT1 and miR-342-3p in CSCC tissues was negatively correlated. This study is the first to demonstrate that the lncRNA NEAT1, as a ceRNA, affects the proliferation of skin squamous cell carcinoma cells through the miR-342-3p/CUL4B/PI3K-Akt signaling pathway. Therefore, lncRNA NEAT1 could be a biological marker or target for CSCC diagnosis or treatment.

Inhibition of LncRNA-NEAT1 alleviates intestinal epithelial cells (IECs) dysfunction in ulcerative colitis by maintaining the homeostasis of the glucose metabolism through the miR-410-3p-LDHA axis

Dysfunction of intestinal epithelial cells (IECs) leads to intestinal epithelial barrier damage and critically involves in the pathogenesis and development of ulcerative colitis (UC). Accumulating studies revealed essential functions of non-coding RNAs in UC. LncRNA NEAT1 (long non-coding RNA nuclear paraspeckle assembly transcript 1) is frequently dysregulated in diverse human diseases. Currently, the precise roles of NEAT1 in the dysfunction of IECs during UC remain unclear. We report NEAT1 was significantly upregulated in IECs from UC patients. In addition, microRNA-410-3p was remarkedly suppressed in IECs from UC patients. Silencing NEAT1 effectively ameliorates the LPS-induced IECs dysfunction. Bioinformatical analysis, RNA pull-down and luciferase assays illustrated that NEAT1 sponged miR-410-3p to downregulate its expression in IECs. Interestingly, the glucose metabolism was obviously elevated in IECs from UC compared with normal colon tissues. Furthermore, NEAT1 promoted and miR-410-3p suppressed glucose metabolism of IECs. We identified lactate dehydrogenase A (LDHA), a glucose metabolism key enzyme, was a direct target of miR-410-3p in IECs. Rescue experiments verified that restoration of miR-410-3p in NEAT1-overexpressing IECs successfully overcame the NEAT1-promoted cell death under LPS treatment by targeting LDHA. In summary, these results unveiled new roles and molecular mechanisms for the NEAT1-mediated IECs dysfunction during the ulcerative colitis.

Expression and functions of long non-coding RNA NEAT1 and isoforms in breast cancer

NEAT1 is a highly abundant nuclear architectural long non-coding RNA. There are two overlapping NEAT1 isoforms, NEAT1_1 and NEAT1_2, of which the latter is an essential scaffold for the assembly of a class of nuclear ribonucleoprotein bodies called paraspeckles. Paraspeckle formation is elevated by a wide variety of cellular stressors and in certain developmental processes, either through transcriptional upregulation of the NEAT1 gene or through a switch from NEAT1_1 to NEAT1_2 isoform production. In such conditions, paraspeckles modulate cellular processes by sequestering proteins or RNA molecules. NEAT1 is abnormally expressed in many cancers and a growing body of evidence suggests that, in many cases, high NEAT1 levels are associated with therapy resistance and poor clinical outcome. Here we review the current knowledge of NEAT1 expression and functions in breast cancer, highlighting its established role in postnatal mammary gland development. We will discuss possible isoform-specific roles of NEAT1_1 and NEAT1_2 in different breast cancer subtypes, which critically needs to be considered when studying NEAT1 and breast cancer.

Recent advances of NEAT1-miRNA interactions in cancer

With high incidence rate, cancer is the main cause of death in humans. Non-coding RNAs, as novel master regulators, especially long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), play important roles in the regulation of tumorigenesis. lncRNA NEAT1 has recently gained much attention, as it is dysregulated in a broad spectrum of cancers, where it acts as either an oncogene or a tumor suppressor gene. Accumulating evidence shows that NEAT1 is correlated with the process of carcinogenesis, including proliferation, invasion, survival, drug resistance, and metastasis. NEAT1 is considered to be a biomarker and a novel therapeutic target for the diagnosis and prognosis of different cancer types. The mechanisms by which NEAT1 plays a critical role in cancers are mainly via interactions with miRNAs. NEAT1-miRNA regulatory networks play significant roles in tumorigenesis, which has attracted much attention from researchers around the world. In this review, we summarize the interaction of NEAT1 with miRNAs in the regulation of protein-coding genes in cancer. A better understanding of the NEAT1-miRNA interactions in cancer will help develop new diagnostic biomarkers and therapeutic approaches.

The ncRNA-Mediated Overexpression of Ferroptosis-Related Gene EMC2 Correlates With Poor Prognosis and Tumor Immune Infiltration in Breast Cancer

Ferroptosis is an iron-dependent programmed cell death process. Although ferroptosis inducers hold promising potential in the treatment of breast cancer, the specific role and mechanism of the ferroptosis-related gene EMC2 in breast cancer have not been entirely determined. The potential roles of EMC2 in different tumors were explored based on The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression (GTEx), Gene Expression Profiling Interactive Analysis 2 (GEPIA2), Tumor Immune Estimation Resource (TIMER), Shiny Methylation Analysis Resource Tool (SMART), starBase, and cBioPortal for cancer genomics (cBioPortal) datasets. The expression difference, mutation, survival, pathological stage, DNA methylation, non-coding RNAs (ncRNAs), and immune cell infiltration related to EMC2 were analyzed. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to identify the differences in biological processes and functions among different related genes. The expression levels of core prognostic genes were then verified in breast invasive carcinoma samples using immunohistochemistry and breast invasive carcinoma cell lines using real-time polymerase chain reaction. High expression levels of EMC2 were observed in most cancer types. EMC2 expression in breast cancer tissue samples correlated with poor overall survival. EMC2 was mutated and methylated in a variety of tumors and affected survival. The LINC00665-miR-410-3p axis was identified as the most potential upstream ncRNA-related pathway of EMC2 in breast cancer. EMC2 levels were significantly positively correlated with tumor immune cell infiltration, immune cell biomarkers, and immune checkpoint expression. Our study offers a comprehensive understanding of the oncogenic roles of EMC2 across different tumors. The upregulation of EMC2 expression mediated by ncRNAs is related to poor prognosis and tumor immune infiltration in breast cancer.

NEAT1 as a competing endogenous RNA in tumorigenesis of various cancers: Role, mechanism and therapeutic potential

The nuclear paraspeckle assembly transcript 1 (NEAT1) is a long non-coding RNA (lncRNA) that is upregulated in a variety of human cancer types. Increasing evidence has shown that the elevation of NEAT1 in cancer cells promotes cell growth, migration, and invasion and inhibits cell apoptosis. It is also known that lncRNAs act as a competing endogenous RNA (ceRNA) by sponging microRNAs (miRNAs) to alter the expression levels of their target genes in the development of cancers. Therefore, it is important to understand the molecular mechanisms underlying this observation. In this review, specific emphasis was placed on NEAT1's role in tumor development. We also summarize and discuss the feedback roles of NEAT1/miRNA/target network in the progression of various cancers. As our understanding of the role of NEAT1 during tumorigenesis improves, its therapeutic potential as a biomarker and/or target for cancer also becomes clearer.

The whole profiling and competing endogenous RNA network analyses of noncoding RNAs in adipose-derived stem cells from diabetic, old, and young patients

Background

Mesenchymal stem cells including adipose-derived stem cells (ASCs) have a considerable potential in the field of translational medicine. Unfortunately, multiple factors (e.g., older age, co-existing diabetes, and obesity) may impair cellular function, which hinders the overall effectiveness of autologous stem cell therapy. Noncoding RNAs—including microRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs)—have been shown to play important roles in stem cell biology. However, the overall diabetes-related and aging-related expression patterns and interactions of these RNAs in ASCs remain unknown.

Method

The phenotypes and functions of ASCs isolated from diabetic (D-ASCs), old (O-ASCs), and young (Y-ASCs) donors were evaluated by in vitro assays. We conducted high-throughput RNA sequencing (RNA-seq) in these ASCs to identify the differentially expressed (DE) RNAs. Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, and protein-protein interaction (PPI) analyses were performed to investigate mRNAs with significant differences among groups. The lncRNA- or circRNA-associated competing endogenous RNA (ceRNA) networks were constructed based on bioinformatics analyses and real-time polymerase chain reaction (RT-PCR) results. The miR-145-5p mimics were transfected into O-ASCs and verified by PCR.

Results

ASCs from diabetic and old donors showed inferior migration ability and increased cellular senescence. Furthermore, O-ASCs have decreased capacities for promoting endothelial cell angiogenesis and fibroblast migration, compared with Y-ASCs. The DE miRNAs, mRNAs, lncRNAs, and circRNAs were successfully identified by RNA-seq in O-ASCs vs. Y-ASCs and D-ASCs vs. O-ASCs. GO and KEGG analyses demonstrated that DE mRNAs were significantly enriched in aging and cell senescence terms separately. PPI networks revealed critical DE mRNAs in the above groups. RNAs with high fold changes and low p values were validated by PCR. ceRNA networks were constructed based on bioinformatics analyses and validated RNAs. Additionally, the lncRNA RAET1E-AS1–miR-145-5p–WNT11/BMPER axis was validated by PCR and correlation analyses. Finally, the overexpression of miR-145-5p was found to rejuvenate O-ASCs phenotype and augment the functionality of these cells.

Conclusion

Our research may provide insights regarding the underlying mechanisms of ASC dysfunction; it may also offer novel targets for restoring therapeutic properties in ASCs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02388-5.

Long non-coding RNA ADAMTS9-AS1 inhibits the progression of prostate cancer by modulating the miR-142-5p/CCND1 axis

BACKGROUND

Emerging evidence has implied the importance of long non-coding RNAs in cancer development, including prostate cancer (PCa). Bioinformatic analyses have identified that ADAMTS9-AS1 may play a role in cancer progression.

METHODS

A quantitative real-time polymerase chain reaction was conducted to measure ADAMTS9-AS1 expression level at messenger RNA level. In vitro functional analyses were performed to investigate cell behaviors status under different conditions. Moreover, rescue assays were conducted to explore the potential mechanisms of ADAMTS9-AS1 in PCa progression.

RESULTS

ADAMTS9-AS1 expression is down-regulated in PCa. Forcing ADAMTS9-AS1 expression impedes PCa cell proliferation via initiating cell apoptosis. Importantly, microRNA-142-5p (miR-142-5p) mimic and small-interfering RNA targeting cyclin D1 (CCND1, si-CCND1) could attenuate the inhibitory effects of ADAMTS9-AS1 overexpression on PCa cell growth.

CONCLUSIONS

Collectively, our results indicate that ADAMTS9-AS1 suppresses PCa progression by regulating the miR-142-5p/CCND1 axis, which provides a new mechanism for the progression of PCa.