GAS5, a non-protein-coding RNA, controls apoptosis and is downregulated in breast cancer (original) (raw)
Related papers
Long non-coding RNA GAS5 regulates apoptosis in prostate cancer cell lines
Biochimica et biophysica acta, 2013
While the role of small non-coding RNAs, such as miRNAs, in apoptosis control is well established, long non-coding RNAs (lncRNAs) have received less attention. Growth Arrest-Specific 5 (GAS5) encodes multiple snoRNAs within its introns, while exonic sequences produce lncRNA which can act as a riborepressor of the glucocorticoid and related receptors. GAS5 negatively regulates the survival of lymphoid and breast cells, and is aberrantly expressed in several cancers. Although cellular GAS5 levels decline as prostate cancer cells acquire castration-resistance, the influence of GAS5 on prostate cell survival has not been determined. To address this question, prostate cell lines were transfected with GAS5-encoding plasmids or GAS5 siRNAs, and cell survival was assessed. Basal apoptosis increased, and cell survival decreased, after transfection of 22Rv1 cells with plasmids encoding GAS5 transcripts, including mature GAS5 lncRNA. Similar effects were observed in PC-3 cells. In stable clone...
Tumor Suppressive Effects of GAS5 in Cancer Cells
Non-Coding RNA
In recent years, long non-coding RNAs (lncRNAs) have been shown to play important regulatory roles in cellular processes. Growth arrests specific transcript 5 (GAS5) is a lncRNA that is highly expressed during the cell cycle arrest phase but is downregulated in actively growing cells. Growth arrests specific transcript 5 was discovered to be downregulated in several cancers, primarily solid tumors, and it is known as a tumor suppressor gene that regulates cell proliferation, invasion, migration, and apoptosis via multiple molecular mechanisms. Furthermore, GAS5 polymorphism was found to affect GAS5 expression and functionality in a cell-specific manner. This review article focuses on GAS5’s tumor-suppressive effects in regulating oncogenic signaling pathways, cell cycle, apoptosis, tumor-associated genes, and treatment-resistant cells. We also discussed genetic polymorphisms of GAS5 and their association with cancer susceptibility.
The Biological Role and Translational Implications of the Long Non-Coding RNA GAS5 in Breast Cancer
Cancers
The lncRNA GAS5 plays a significant role in tumorigenicity and progression of breast cancer (BC). In this review, we first summarize the role of GAS5 in cell biology, focusing on its expression data in human normal tissues. We present data on GAS5 expression in human BC tissues, highlighting its downregulation in all major BC classes. The main findings regarding the molecular mechanisms underlying GAS5 dysregulation are discussed, including DNA hypermethylation of the CpG island located in the promoter region of the gene. We focused on the action of GAS5 as a miRNA sponge, which is able to sequester microRNAs and modulate the expression levels of their mRNA targets, particularly those involved in cell invasion, apoptosis, and drug response. In the second part, we highlight the translational implications of GAS5 in BC. We discuss the current knowledge on the role of GAS5 as candidate prognostic factor, a responsive molecular therapeutic target, and a circulating biomarker in liquid b...
The Non-Coding RNA GAS5 and Its Role in Tumor Therapy-Induced Resistance
International Journal of Molecular Sciences
The growth arrest-specific transcript 5 (GAS5) is a >200-nt lncRNA molecule that regulates several cellular functions, including proliferation, apoptosis, invasion and metastasis, across different types of human cancers. Here, we reviewed the current literature on the expression of GAS5 in leukemia, cervical, breast, ovarian, prostate, urinary bladder, lung, gastric, colorectal, liver, osteosarcoma and brain cancers, as well as its interaction with various miRNAs and its effect on therapy-related resistance in these malignancies. The general consensus is that GAS5 acts as a tumor suppressor across different tumor types and that its up-regulation results in tumor sensitization to chemotherapy or radiotherapy. GAS5 seems to play a previously unappreciated, but significant role in tumor therapy-induced resistance.
Non-Coding RNA, 2019
Long non-coding RNA (lncRNA) genes encode non-messenger RNAs that lack open reading frames (ORFs) longer than 300 nucleotides, lack evolutionary conservation in their shorter ORFs, and do not belong to any classical non-coding RNA category. LncRNA genes equal, or exceed in number, protein-coding genes in mammalian genomes. Most mammalian genomes harbor ~20,000 protein-coding genes that give rise to conventional messenger RNA (mRNA) transcripts. These coding genes exhibit sweeping evolutionary conservation in their ORFs. LncRNAs function via different mechanisms, including but not limited to: (1) serving as “enhancer” RNAs regulating nearby coding genes in cis; (2) functioning as scaffolds to create ribonucleoprotein (RNP) complexes; (3) serving as sponges for microRNAs; (4) acting as ribo-mimics of consensus transcription factor binding sites in genomic DNA; (5) hybridizing to other nucleic acids (mRNAs and genomic DNA); and, rarely, (6) as templates encoding small open reading fram...
Oncology and Translational Medicine, 2022
Objective Long non-coding RNAs (lncRNAs) regulate tumor development and progression by promoting tumor proliferation, invasion, and metastasis. The aim of the study was to investigate the effects of lncRNA growth arrest-special 5 (GAS5) on proliferation and apoptosis of hepatocellular carcinoma (HCC) cells through miR-26a-5p action. Methods Expression levels of GAS5 were detected in cancerous and paracancerous tissue of 80 HCC patients by RT-qPCR. The starBase tool predicted that GAS5 had binding sites for the miRNA miR-26a-5p, which was also highly expressed in HCC tissue. The relationship between GAS5 and miR-26a-5p was confirmed using a luciferase reporter assay. The role of these lncRNAs was further explored by transfecting plasmids into SMMC-7721 cells and classifying the cells as follows: NC group, GAS5 group, anti-miR-26a-5p group, and GAS5 + miR-26a-5p group. Cell proliferation, cell cycle, and apoptosis were detected in each group. The relationship between miR-26a-5p and phosphatase and tensin homolog deleted on chromosome 10 (PTEN) was analyzed by TargetScan database prediction and luciferase reporter assay. Western blotting was used to quantify PTEN, phosphatidylinositol 3-kinase (PI3K), phosphorylated protein kinase B (p-Akt), cyclin D1, and human P27 protein (P27). Results GAS5 was downregulated, while miR-26a-5p was upregulated in HCC tissue compared to in paracancerous tissue. High GAS5 levels and low miR-26a-5p levels inhibited cell proliferation, increased the number of G0/G1 phase cells, promoted cell apoptosis, promoted PTEN and P27 expression, and inhibited PI3K, P-Akt, and cyclin D1 expression at the protein level. Upregulation of miR-26a-5p attenuated the effects of GAS5 upregulation on the proliferation, cell cycle, and apoptosis of HCC cells and on the expression of PTNE/PI3K/Akt signaling pathway-related proteins. Conclusion Low GAS5 levels regulate the proliferation and apoptosis of HCC cells via the PTNE/PI3K/ Akt signaling pathway and are linked to upregulation of miR-26a-5p.
GAS5 long non-coding RNA in malignant pleural mesothelioma
Molecular Cancer, 2014
Background: Malignant pleural mesothelioma (MPM) is an aggressive cancer with short overall survival. Long non-coding RNAs (lncRNA) are a class of RNAs more than 200 nucleotides long that do not code for protein and are part of the 90% of the human genome that is transcribed. Earlier experimental studies in mice showed GAS5 (growth arrest specific transcript 5) gene deletion in asbestos driven mesothelioma. GAS5 encodes for a lncRNA whose function is not well known, but it has been shown to act as glucocorticoid receptor decoy and microRNA "sponge". Our aim was to investigate the possible role of the GAS5 in the growth of MPM.
Journal of Biological Chemistry, 2015
Background: Long non-coding RNAs function as competing endogenous RNAs (ceRNAs). Whether growth arrest-specific transcript 5 (GAS5) acts as a ceRNA for microRNA-222 in liver fibrosis remains undefined. Results: GAS5 increases p27 expression as a ceRNA for microRNA-222, thereby inhibiting liver fibrosis progression. Conclusion: The GAS5/microRNA-222/p27 axis underlies the pathogenesis of liver fibrosis. Significance: The ceRNA network helps to understand liver fibrogenesis. Effective control of hepatic stellate cell (HSC) activation and proliferation is critical to the treatment of liver fibrosis. Long non-coding RNAs have been shown to play a pivotal role in the regulation of cellular processes. It has been reported that growth arrest-specific transcript 5 (GAS5) acts as a crucial mediator in the control of cell proliferation and growth. However, little is known about the role and underlying mechanism of GAS5 in liver fibrosis. In this study, our results indicated that GAS5 expression was reduced in mouse, rat, and human fibrotic liver samples and in activated HSCs. Overexpression of GAS5 suppressed the activation of primary HSCs in vitro and alleviated the accumulation of collagen in fibrotic liver tissues in vivo. We identified GAS5 as a target of microRNA-222 (miR-222) and showed that miR-222 could inhibit the expression of GAS5. Interestingly, GAS5 could also repress miR-222 expression. A pulldown assay further validated that GAS5 could directly bind to miR-222. As a competing endogenous RNAs, GAS5 had no effect on primary miR-222 expression. In addition, GAS5 was mainly localized in the cytoplasm. Quantitative RT-PCR further demonstrated that the copy numbers of GAS5 per cell are higher than those of miR-222. GAS5 increased the level of p27 protein by functioning as a competing endogenous RNA for miR-222,
Small Nucleolar Derived RNAs as Regulators of Human Cancer
In the past decade, RNA fragments derived from full length small nucleolar RNAs (snoRNAs) have been shown to be specifically excised and functional. These sno-derived RNAs (sdRNAs) have been implicated as gene regulators in a multitude of cancers, controlling a variety of genes post-transcriptionally via association with the RNA-induced silencing complex (RISC). In this review, we have summarized the literature connecting sdRNAs to cancer gene regulation. SdRNAs possess miRNA-like functions, and are able to fill the role of tumor-suppressor or tumor-promoter in a tissue context-dependent manner. Indeed, there are many miRNAs that are actually derived from snoRNA transcripts, meaning that they are truly sdRNAs and as such are included in this review. As sdRNAs are frequently discarded from ncRNA analyses, we emphasize that sdRNAs are functionally relevant gene regulators and likely represent an overlooked subclass of miRNAs. Based on the evidence provided by the papers reviewed here,...