Altered expression of long non-coding RNA GAS5 in digestive tumors

GAS5 lncRNA: A biomarker and therapeutic target in breast cancer

Breast cancer is one of the most common causes of cancer-related mortality globally, and its aggressive phenotype results in poor treatment outcomes. Growth Arrest-Specific 5 long non-coding RNA has attracted considerable attention due to its pivotal function in apoptosis regulation and tumor aggressiveness in breast cancer. Gas5 enhances apoptosis by regulating apoptotic proteins, such as caspases and BCL2 family proteins, and the sensitivity of BCCs to chemotherapeutic agents. At the same time, low levels of GAS5 increased invasion, metastasis, and overall tumor aggressiveness. GAS5 also regulates EMT markers, critical for cancer metastasis, and influences tumor cell proliferation by regulating various signaling components. As a result, GAS5 can be restored to suppress tumor development as a possible therapeutic strategy, which might present promising prospects for a patient's treatment. Its activity levels might also be a crucial indicator and diagnostic parameter for prediction. This review highlights the significant role of GAS5 in modulating apoptosis and tumor aggressiveness in breast cancer, emphasizing its potential as a therapeutic target for breast cancer treatment and management.

The Implication of Growth Arrest-Specific 5 rs145204276 Polymorphism and Serum Expression of Sirtuin 1, Transforming Growth Factor-Beta, and microRNA-182 in Breast Cancer

Background

Breast cancer (BC) patients have a higher chance of survival if it is diagnosed at an early stage, which is essential for efficient treatment of the condition. The results of an elevated risk of cancer, including BC, previously associated with the ins/del polymorphism rs145204276 in the promoter region of growth arrest-specific 5 (GAS5) are still up for debate. Thus, this study aimed to appraise the frequency of the GAS5 rs145204276 variant with BC risk and demonstrate the potential impact of the sirtuin 1 (SIRT-1), transforming growth factor-beta (TGF-β), and microRNA-182 (miR-182) expression and their diagnostic value in BC.

Methods

Blood samples of 155 patients with BC and fibroadenoma and 80 healthy controls were analyzed for GAS5 rs145204276 single nucleotide polymorphism (SNP), SIRT-1, TGF-β, and miRNA-182 expression levels.

Results

Ins/ins genotype and ins allele frequencies for GAS5 rs145204276 were considerably higher in BC patients compared with controls. Patients with BC had significantly greater serum levels of TGF-β, miR-182, and SIRT-1 expression.

Conclusions

The SIRT-1, TGF-β, and miR-182 genes provide novel, noninvasive diagnostic biomarkers for BC.

Upregulation of Long Noncoding RNA PCAT1 in Iranian Patients with Colorectal Cancer and Its Performance as a Potential Diagnostic Biomarker

Background: Long noncoding RNAs (lncRNAs) as critical molecules play an essential role in the development of cancers. In colorectal cancer (CRC), various lncRNAs are related to cell proliferation, apoptosis, migration, and invasion. LncRNA prostate cancer-associated transcript 1 (PCAT-1), as an oncogenic factor, is a diagnostic biomarker that regulates cell proliferation, migration, invasion, and apoptosis. Methods: This study evaluated the relationship between PCAT-1, CRC occurrence, and pathological features of Iranian patients. The studied samples included 100 colorectal tumor tissues and 100 adjacent healthy tissues of Iranian CRC patients. RNAs were extracted from cancerous and noncancerous tissues to synthesize complementary DNA. The expression level of PCAT-1 was assessed using the real-time PCR method, and the data analysis was assessed using SPSS software. Results: In this study, expression level of PCAT-1 in tumor tissue was significantly increased in Iranian patients, and pathological studies of the patients had no significant relationship with the PCAT-1 expression profile. Conclusion: Our results suggested that the high expression of PCAT-1 resulted in the occurrence of colorectal tumor tissues in Iranian patients, which can be considered a diagnostic biomarker in CRC.

Functional SNPs in SYISL promoter significantly affect muscle fiber density and muscle traits in pigs

Our previous studies showed that SYISL is a negative regulator of muscle growth and regeneration in mice, pigs and humans. SYISL knockout resulted in an increase in the density of muscle fibers and muscle growth. However, it is unclear whether there are natural mutations in pig SYNPO2 intron sense-overlapping lncRNA (pSYISL) that affect the expression of pSYISL and muscle growth traits. In this study, three SNPs in exons and six SNPs within the promoter of pSYISL were identified. Association analysis showed that the two SNPs in exons are significantly associated with loin muscle area (p < 0.05); the six SNPs in the promoter that show complete linkage are significantly associated with live backfat thickness and live loin muscle area in American Large White pigs. Bioinformatics and luciferase reporter assays as well as in vitro binding experiments indicated that the mutation of SNP rs702045770 (g.539G>A) leads to the loss of YY1 binding to the promoter, thus affecting the expression level of pSYISL, and we found that Jiangshan Black pigs with genotype GG have a higher expression level of pSYISL than genotype AA individuals, but the muscle fiber density was significantly lower than in genotype AA individuals. Furthermore, the association analysis showed that the carcass backfat thickness of genotype GG of SNP rs702045770 was significantly higher than that of other genotypes in (Pietrain × Duroc) × (Landrace × Yorkshire) crossbred pigs (p < 0.05). The glycolytic potential of genotype GG was significantly higher than that of other genotypes (p < 0.05). These results provide novel insight into the identification of functional SNPs in non-coding genomic regions.

Combined Evaluation of mRNA and Protein Expression, Promoter Methylation, and Immune Infiltration of UBE2I in Pan-Digestive System Tumors

Background

Digestive system tumors (DSTs) have high morbidity and mortality worldwide. This study explored the potential value of ubiquitin-conjugating enzyme E2 I (UBE2I) in pan-digestive system tumors (pan-DSTs).

Methods

Differential expression, tumor stages, and survival outcomes of UBE2I in pan-DSTs were determined using the GEPIA database. The TIMER database was used to confirm the correlation of UBE2I expression with pan-DSTs and immune infiltrates. Differential analyses of UBE2I promoter methylation and protein levels were performed using the UALCAN database. The underlying mechanisms of UBE2I involvement in pan-DSTs were visualized using interaction networks. The diagnostic value of UBE2I in pan-DSTs was identified using the Oncomine database.

Results

UBE2I was differentially and highly expressed in cholangiocarcinoma (CHOL), pancreatic adenocarcinoma (PAAD), colon adenocarcinoma (COAD), rectal adenocarcinoma (READ), liver hepatocellular carcinoma (LIHC), and stomach adenocarcinoma (STAD). According to survival analysis, upregulated UBE2I was associated with adverse overall and disease-free survival in PAAD and favorable overall survival in READ. UBE2I expression was partially linked to the purity of immune infiltration in COAD, LIHC, PAAD, READ, and STAD, as indicated by the immune infiltration analysis. Promoter methylation analysis showed differential and high methylation of UBE2I in PAAD as well as stratified analysis by gender, nodal metastasis, and race. Protein expression analysis in colon cancer revealed that UBE2I had differential and high expression in tumors as well as stratified analysis by gender, tumor histology, race, and tumor stage. Mechanism explorations demonstrated that in COAD and PAAD, UBE2I was involved in spliceosomal snRNP complex, Notch signaling pathway, etc. Diagnostic analysis indicated that UBE2I had consistent diagnostic value for COAD and PAAD.

Conclusions

Upregulated UBE2I may be a diagnostic and surveillance predictive signature for PAAD and COAD. The potential significance of immune infiltrates and promoter methylation in PAAD and COAD needs further exploration.

lncRNA polymorphism affects the prognosis of gastric cancer

Background

Previous studies have found that lncRNA polymorphisms are associated with the prognosis of gastric cancer (GC), but the specific roles of many lncRNA polymorphism sites in gastric cancer are still unclear. Our study aims to deeply explore the relationship between genetic polymorphism of lncRNA and the prognosis of GC.

Methods

The genotypes of candidate SNP locus were detected by Sequenom Mass ARRAY SNP. We deeply analyzed the association of lncRNA polymorphisms with GC prognosis by univariate and multivariate Cox regression, stratified analysis, conjoint analysis, and log-rank test.

Results

We found that mutations at rs2579878 and rs10036719 loci reduced the risk of poor prognosis of GC. Stratified analysis showed that rs2795025, rs10036719, and rs12516079 polymorphisms were all associated with tumor prognosis. In addition, conjoint analyses showed that the interaction between these two polymorphic sites (rs2795025 and rs12516079) could increase the risk of poor prognosis. Multivariate analysis also found that the AG/AA genotype of rs10036719 and AG genotype of rs12516079 were independent prognostic factors. Moreover, the high expression of both CCDC26 and LINC02122 were shown to be associated with the poor survival status of GC patients.

Conclusions

We find that the genetic polymorphism of lncRNA plays a role in the development of GC and is closely related to the survival time of patients. It could serve as a predictor of the prognosis of GC.

LncRNA growth arrest specific transcript 5 inhibits the growth of pituitary neuroendocrine tumors via miR-27a-5p/cylindromatosis axis

The long noncoding RNA growth arrest-specific transcript 5 (GAS5) has been reported to function as a suppressor in many cancers. However, the role and mechanism of lncRNA GAS5 in pituitary neuroendocrine tumors (PitNETs) remain unclear. Here, we found that lncRNA GAS5 and cylindromatosis (CYLD) expression was downregulated in invasive PitNET tissues and was negatively correlated with miR-27a-5p expression. LncRNA GAS5 overexpression inhibited proliferation of PitNETs cell line MMQ and GH3 cells and induced cell apoptosis, simultaneously, inhibited miR-27a-5p expression and increased CYLD expression. Moreover, miR-27a-5p mimic significantly decreased the luciferase activities of lncRNA GAS5 and CYLD luciferase reporter vector and downregulated CYLD expression, while miR-27a-5p inhibitor increased the expression of CYLD in MMQ and GH3 cells. Furthermore, RNA-immunoprecipitation assay revealed the direct binding between lncRNA GAS5 and miR-27a-5p. Additionally, miR-27a-5p mimic or silenced CYLD attenuated the effect of lncRNA GAS5 on MMQ and GH3 cell proliferation. In vivo lncRNA GAS5 overexpression inhibited GH3 cell tumor growth, while miR-27a-5p mimic or silenced CYLD attenuated the effect of lncRNA GAS5 on GH3 cell tumor growth. These results suggest that lncRNA GAS5 acts as an endogenous sponge by binding miR-27a-5p to increase the expression of its target gene CYLD, thereby inhibits PitNETs cell proliferation and tumor growth.

LncRNA GAS5 Knockdown Mitigates Hepatic Lipid Accumulation via Regulating MiR-26a-5p/PDE4B to Activate cAMP/CREB Pathway

OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) can be attributed to the dysregulation of hepatic lipid metabolism; however, its cellular and molecular mechanisms remain unclear. This study aims to explore the effect of long non-coding RNA growth arrest specific 5 (GAS5) on hepatic lipid metabolism in fatty liver models.

METHODS

Obese mice, high fat diet-fed mice and free fatty acid-stimulated cells were used for GAS5 expression detection. GAS5 overexpression or knockdown models were established to elucidate the regulatory function of GAS5 in de novo lipogenesis (DNL) and mitochondrial function. Bioinformatic analyses and dual luciferase assays were used to investigate the interaction between GAS5, miR-26a-5p and phosphodiesterase (PDE) 4B. The involvement of the cyclic adenosine monophosphate (cAMP)/cAMP-response element-binding protein (CREB) pathway was evaluated using H89 and forskolin treatment.

RESULTS

GAS5 was activated in vitro and in vivo fatty liver models. Knockdown of GAS5 reduced lipid droplet accumulation, DNL associated enzymes and preserved mitochondrial function, while GAS5 overexpression exacerbated hepatic lipid accumulation. Mechanistically, GAS5 sponged miR-26a-5p to increase PDE4B expression and subsequently modulated DNL and mitochondrial function via the cAMP/CREB pathway.

CONCLUSION

Downregulation of GAS5 can activate the cAMP/CREB pathway through miR-26a-5p/PDE4B axis to mitigate hepatic lipid accumulation. This study provides evidence that downregulation of GAS5 may be a potential therapeutic option for the treatment of NAFLD.

Long Noncoding Competing Endogenous RNA Networks in Pancreatic Cancer

Pancreatic cancer (PC) is a highly malignant disease characterized by insidious onset, rapid progress, and poor therapeutic effects. The molecular mechanisms associated with PC initiation and progression are largely insufficient, hampering the exploitation of novel diagnostic biomarkers and development of efficient therapeutic strategies. Emerging evidence recently reveals that noncoding RNAs (ncRNAs), including long ncRNAs (lncRNAs) and microRNAs (miRNAs), extensively participate in PC pathogenesis. Specifically, lncRNAs can function as competing endogenous RNAs (ceRNAs), competitively sequestering miRNAs, therefore modulating the expression levels of their downstream target genes. Such complex lncRNA/miRNA/mRNA networks, namely, ceRNA networks, play crucial roles in the biological processes of PC by regulating cell growth and survival, epithelial-mesenchymal transition and metastasis, cancer stem cell maintenance, metabolism, autophagy, chemoresistance, and angiogenesis. In this review, the emerging knowledge on the lncRNA-associated ceRNA networks involved in PC initiation and progression will be summarized, and the potentials of the competitive crosstalk as diagnostic, prognostic, and therapeutic targets will be comprehensively discussed.

Association between long non-coding RNA (lncRNA) GAS5 polymorphism rs145204276 and cancer risk

OBJECTIVE

The long non-coding RNA (lncRNA) growth arrest‑specific transcript 5 (GAS5) plays an important role in various tumors, and an increasing number of studies have explored the association of the GAS5 rs145204276 polymorphism with cancer risk with inconclusive results.

METHODS

PubMed, Medline, EMBASE, Cochrane databases, and Web of Science were searched, and nine studies involving 6107 cases and 7909 controls were deemed eligible. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated to evaluate the relationship between rs145204276 and cancer risk in six genetic models.

RESULTS

The pooled results suggest that the variant allele del was not associated with overall cancer risk. However, the subgroup analysis showed that allele del was significantly associated with a 22% decreased risk of gastrointestinal cancer (OR = 0.78, 95% CI: 0.72-0.85). Both sensitivity analyses and trial sequential analyses (TSA) demonstrated that the subgroup results were reliable and robust. Moreover, False-Positive Report Probability (FPRP) analysis indicated that the results had true significant correlations.

CONCLUSION

These findings provide evidence that the GAS5 rs145204276 polymorphism is associated with the susceptibility to gastrointestinal cancer. Further studies with different ethnicities and larger sample sizes are warranted to confirm these results.

Genetic Variants of lncRNA GAS5 Are Associated with the Clinicopathologic Development of Oral Cancer

The long noncoding RNA, Growth arrest-specific 5 (GAS5) plays a crucial role in the development of oral cancer. However, potential genetic variants in GAS5 that affect the susceptibility and progression of oral cancer have rarely been explored. In this study, two loci of GAS5 single nucleotide polymorphisms (SNPs) (rs145204276 and rs55829688) were genotyped by using the TaqMan allelic discrimination in 1125 oral cancer patients and 1195 non-oral-cancer individuals. After statistical analyses, the distribution of both the GAS5 SNP rs145204276 and GAS5 SNP rs55829688 frequencies were similar between the study and control groups. However, the patients with GAS5 SNP rs145204276 variants (Ins/Del or Del/Del) showed a higher tendency of moderate to poor cell differentiation of oral cancer (OR: 1.454, 95% CI: 1.041–2.031, p = 0.028). Moreover, the GAS5 SNP rs145204276 variants (Ins/Del or Del/Del) in the non-alcohol-drinking population were associated with significantly advanced tumor stage (OR: 1.500, 95% CI: 1.081–2.081, p = 0.015) and larger tumor size (OR: 1.494, 95% CI: 1.076–2.074, p = 0.016). Furthermore, individuals with the GAS5 SNP rs145204276 variant were associated with a higher expression of GAS5 in the GTEx database (p = 0.002), and the higher GAS5 level was associated with poor cell differentiation, advanced tumor stage and larger tumor size in head and neck squamous cell carcinoma from the TCGA database (all p < 0.05). In conclusion, the GAS5 SNP rs145204276 variant is related to poor-differentiation cell status in oral cancer. Besides, the presence of the GAS5 SNP rs145204276 variant is associated with a worse tumor stage and tumor size in oral cancer patients without alcohol drinking.

Recent advances in the regulation of ABCA1 and ABCG1 by lncRNAs

Coronary heart disease (CHD) with atherosclerosis is the leading cause of death worldwide. ABCA1 and ABCG1 promote cholesterol efflux to suppress foam cell generation and reduce atherosclerosis development. Long noncoding RNAs (lncRNAs) are emerging as a unique group of RNA transcripts that longer than 200 nucleotides and have no protein-coding potential. Many studies have found that lncRNAs regulate cholesterol efflux to influence atherosclerosis development. ABCA1 is regulated by different lncRNAs, including MeXis, GAS5, TUG1, MEG3, MALAT1, Lnc-HC, RP5-833A20.1, LOXL1-AS1, CHROME, DAPK1-IT1, SIRT1 AS lncRNA, DYNLRB2-2, DANCR, LeXis, LOC286367, and LncOR13C9. ABCG1 is also regulated by different lncRNAs, including TUG1, GAS5, RP5-833A20.1, DYNLRB2-2, ENST00000602558.1, and AC096664.3. Thus, various lncRNAs are associated with the roles of ABCA1 and ABCG1 on cholesterol efflux in atherosclerosis regulation. However, some lncRNAs play dual roles in ABCA1 expression and atherosclerosis, and the functions of some lncRNAs in atherosclerosis have not been investigated in vivo. In this article, we review the roles of lncRNAs in atherosclerosis and focus on new insights into lncRNAs associated with the roles of ABCA1 and ABCG1 on cholesterol efflux and the potential of these lncRNAs as novel therapeutic targets in atherosclerosis.

Long Noncoding RNAs in Gastrointestinal Cancer: Tumor Suppression Versus Tumor Promotion

Approximately 80% of the human genome harbors biochemical marks of active transcription that its majority transcribes to noncoding RNAs, namely long noncoding RNAs (lncRNAs). LncRNAs are heterogeneous RNA transcripts that regulate critical biological processes such as cell survival and death. They involve in the progression of different cancers by affecting transcriptional and post-transcriptional modifications as well as epigenetic control of numerous tumor suppressors and oncogenes. Recent findings show that aberrant expression of lncRNAs is associated with tumor initiation, progression, invasion, and overall survival of patients with gastrointestinal (GI) cancers. Some lncRNAs play as tumor suppressors in all GI cancers, but others play as tumor promoters. However, some other lncRNAs might function as a tumor suppressor in one GI cancer, but as a tumor promoter in another GI cancer type. This fact highlights possible context dependency of the expression patterns and roles of at least some lncRNAs in GI cancer development and progression. Here, we review the functional relation of lncRNAs involved in the development and progression of GI cancer by focusing on their roles as tumor suppressor and tumor promoter genes.

The Non-Coding RNA GAS5 and Its Role in Tumor Therapy-Induced Resistance

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.

LncRNA-GAS5 Inhibits Expression of miR 103 and Ameliorates the Articular Cartilage in Adjuvant-Induced Arthritis in Obese Mice

We explored whether long noncoding RNA growth arrest-specific transcript 5 (LncRNA-GAS5) small interfering RNA (siRNA) reduced cartilage destruction in obese mice with adjuvant-induced arthritis. We studied the effects of LncRNA-GAS5 siRNA on the polyarthritis index; hind paw swelling; and the serum levels of certain biochemicals, cytokines, and oxidative stress parameters. We measured the expression levels of matrix metalloproteinases (MMP)-13, NF-κB, fibroblast growth factor (FGF) 21, p38, Akt, and PI3K in cartilage via Western blotting and quantitative reverse transcription PCR. Long noncoding RNA-GAS5 siRNA reduced joint swelling; the serum levels of arthritis-associated biochemicals, cytokines, and oxidative stress markers; and cartilage MMP-13, NF-κB, FGF21, p38, Akt, and PI3K levels. Cartilage miR-103 expression was reduced. Histopathologically, LncRNA-GAS5 siRNA ameliorated the pathological changes of cartilage. Long noncoding RNA-GAS5 siRNA prevented cartilage destruction by inhibiting miR-103 expression.

GAS5 which is regulated by Lhx8 promotes the recovery of learning and memory in rats with cholinergic nerve injury

Damage to the cholinergic system in central nervous system injuries such as traumatic brain injury (TBI) and neurodegenerative diseases leads to impaired learning and cognition. Neural stem cells (NSCs) have self-renewal capacity and multi-directional differentiation potential and considered the best source of cells for cell replacement therapy. However, how to promote the differentiation of NSCs into neurons is a major challenge in current research. Lhx8 has a specific effect on the development of the cholinergic nervous system, but its exact function is unclear. In this study, we found that Lhx8 could regulate the expression of Growth arrest-specific (GAS)5 which has been implicated in cancer but was less studied in the nervous system. Additionally, results from PCR, fluorescence in situ hybridization, and immunocytochemical analyses showed that GAS5 is mainly expressed in the cytoplasm of hippocampal neural stems cells and promotes their differentiation into neurons; the Morris water maze test demonstrated that GAS5 overexpression restored learning and memory in rats with cholinergic injury. These findings indicate that GAS5, which is regulated by Lhx8, improve brain function following cholinergic nerve injury.

Circulating long noncoding RNAs H19 and GAS5 are associated with type 2 diabetes but not with diabetic retinopathy: A preliminary study

Recently, a wide range of biological and pathological roles of long noncoding RNAs (lncRNAs) have been discovered. However, the potential role of circulating lncRNAs H19 and GAS5 in type 2 diabetes mellitus (T2DM) and diabetic retinopathy (DR) is not clear. Here, we assessed the plasma levels of H19 and GAS5 lncRNAs in T2DM patients with/without DR and evaluated if H19 and GAS5 pre-treatment plasma levels are a predictor of early response to a single aflibercept dose in DR subgroup. Plasma lncRNA expression profiles of 119 T2DM patients (66 with DR and 53 without DR) and 110 healthy controls were determined by quantitative reverse transcription PCR. The association of lncRNA expression profiles with clinical features and aflibercept early response in DR patients was investigated. Relative H19 expression levels were significantly increased in T2DM group (including DR and non-DR subgroups) vs. controls, while GAS5 levels were decreased in T2DM group (p < 0.001). There was no significant difference in H19 and GAS5 expression levels between DR and non-DR subgroups. H19 and GAS5 expression profiles were not significantly correlated with clinical parameters or response to aflibercept therapy in DR subgroup. Our findings indicate that the circulating lncRNAs H19 and GAS5 may be associated with T2DM prevalence but may not have an important diagnostic/prognostic role in DR or early response to aflibercept intravitreal injection in DR patients. Large-scale transcriptomic studies are warranted to validate our results and investigate other lncRNA candidates in T2DM.

The mechanisms of lncRNA GAS5 in cardiovascular cells and its potential as novel therapeutic target

Long noncoding RNAs (lncRNAs) are a large class of non (protein)-coding RNAs, which are longer beyond 200 nucleotides. LncRNA GAS5 is widely considered as a tumour suppressor in cell proliferation, apoptosis, cell migration and invasion of tumour cells. Recently, a growing body of evidences indicated that GAS5 was also widely involved in the pathologic process of cardiovascular cells, including regulation of apoptosis and inflammatory injury of cardiomyocytes; proliferation, apoptosis, autophagy and angiogenesis of endothelial cells; and proliferation, migration, apoptosis and differentiation of VSMCs. In this regard, we summarised current studies of GAS5 in cardiovascular cells, which shed light on not only our understanding of the mechanisms of GAS5 in cardiovascular cells but also understanding of the potential of GAS5 as novel therapeutic target.

Roles of HOTAIR in lung cancer susceptibility and prognosis

Background

Long noncoding (lncRNA) single‐nucleotide polymorphisms (SNPs) are associated with the susceptibility to the development of various malignant tumors. The aim of this study was to investigate the roles of HOX transcript antisense intergenic RNA (HOTAIR) and its SNPs in lung cancer.

Methods

Initially, the expression of HOTAIR in different tumors was investigated using the online Gene Expression Profiling Interactive Analysis (GEPIA) resource. Three SNPs (rs920778, rs1899663, and rs4759314) of HOTAIR were identified using the MassArray system. Following this, the relationship between these SNPs and susceptibility to lung cancer was investigated.

Results

Expression of HOTAIR was found to increase in a variety of cancers, including nonsmall cell lung cancer (NSCLC). We found that the genotypes of these SNPs (rs920778, rs1899663, and rs4759314) were not significantly associated with lung cancer type, family history, lymph node metastasis, or lung cancer stage. In gender stratification, the results of rs920778 genotypes showed that, compared to genotype AA, the AG (OR = 0.344, 95% CI: 0.133–0.893, p = .028) and AG + GG (OR = 0.378, 95% CI: 0.153–0.932, p = .035) genotypes of rs920778 are protective factors against NSCLC in females. In smoking stratification, compared with AA of rs920778, the genotype AG + GG (OR = 0.507, 95% CI: 0.263–0.975, p = .042) was a protective factor against NSCLC in nonsmoking people. No statistical differences were observed in the classifications of rs1899663 and rs4759314 genotypes. Linkage disequilibrium analysis revealed a high linkage disequilibrium between the rs920778 and rs1899663 (D′ = 0.99, r² = .74), rs920778 and rs4759314 (D′ = 0.85, r² = .13), and rs1899663 and rs4759314 (D′ = 0.79, r² = .00).

Conclusion

Our study demonstrated that HOTAIR expression increased in NSCLC, and that the genotypes of rs920778 could be useful in the diagnosis and prognosis of lung cancer.

Impact of Gene Polymorphisms in GAS5 on Urothelial Cell Carcinoma Development and Clinical Characteristics

Urothelial cell carcinoma (UCC) is the commonest malignant tumor of the urinary tract and the second most common kidney cancer malignancy. Growth arrest-specific 5 (GAS5), a long noncoding RNA, is encoded by the GAS5 gene and plays a critical role in cellular growth arrest and apoptosis. In the current study, two single nucleotide polymorphisms (SNPs) in the GAS5 gene, rs145204276 and rs55829688, were selected to investigate correlations between these single SNPs and susceptibility to UCC. A total of 430 UCC cases and 860 ethnically matched healthy controls were included. SNP rs145204276 and SNP rs55829688 were determined using a TaqMan genotyping assay. Logistic regression models demonstrated that female patients with UCC carrying the rs145204276 GAS5 Ins/Del or Del/Del genotype had a 3.037-fold higher risk of larger tumor status (95% confidence interval 1.259–7.324) than did rs145204276 wild type (Ins/Ins) carriers (p  =  0.011). The Cancer Genome Atlas validation cohort analysis demonstrated that the expression of GAS5 in female patients with bladder urothelial carcinoma (BLCA) with larger tumor size was much lower than that in patients with a smaller tumor size (p = 0.041). Kaplan-Meier curve analysis and the log–rank test revealed that female patients with BLCA and lower GAS5 expression had poorer overall survival than those with higher GAS5 expression. In conclusion, genetic variations in GAS5 rs145204276 may serve as a critical predictor of the clinical status of female patients with UCC.

Long non-coding RNA GAS5 regulates human B lymphocytic leukaemia tumourigenesis and metastasis by sponging miR-222

Accumulating evidence has shown that lncRNA GAS5 is a novel tumour-promoting RNA that contributes to tumour progression by sponging miRNAs. However, the detailed role of lncRNA GAS5 in B lymphocytic leukaemia is still unclear. A qRT-PCR assay was used to examine the levels of lncRNA GAS5 and miR-222 in leukomonocytes of patients with B lymphocytic leukaemia and in healthy donors. Raji cells were transfected with GAS5 overexpression or shRNA-GAS5 plasmids for 48⁢h, and cell proliferation was assessed by the CCK-8 assay, while apoptosis and cell cycle progression were assessed using flow cytometry. The Transwell assay was applied to detect the invasion of Raji cells with GAS5 overexpression or knockdown. The dual luciferase reporter assay and regression curve were conducted to evaluate the binding interaction between lncRNA GAS5 and miR-222. The results showed that the expression of lncRNA GAS5 was decreased in B lymphocytic leukaemia patients compared with the healthy group, and the levels of lncRNA GAS5 in B lymphocytic leukaemia cell lines were significantly higher than those in the normal B cell line, whereas the levels of miR-222 were increased in B lymphocytic leukaemia patients compared with the healthy group. Moreover, cell culture experiments indicated that lncRNA GAS5 overexpression decreased B lymphocytic leukaemia cell proliferation, promoted B lymphocytic leukaemia cell apoptosis, arrested B lymphocytic leukaemia cells in the G1 phase of the cell cycle, and inhibited B lymphocytic leukaemia cell invasion. Finally, the luciferase reporter assay showed a direct target interaction between lncRNA GAS5 and miR-222. The regression analysis showed a negative correlation between the levels of lncRNA GAS5 and miR-222. Thus, our data suggested that lncRNA GAS5 could effectively sponge miR-222 to modulate human B lymphocytic leukaemia cell tumourigenesis and metastasis. This work advances our understanding of the clinical significance of lncRNA GAS5 from the perspective of lncRNA-miRNA regulation.

Association between lncRNA GAS5, MEG3, and PCAT-1 Polymorphisms and Cancer Risk: A Meta-Analysis

Purpose

Long noncoding RNAs (lncRNAs) have been widely studied, and single nucleotide polymorphisms (SNPs) in lncRNAs are considered to be genetic factors that influence cancer susceptibility. The lncRNA GAS5, MEG3, and PCAT-1 polymorphisms are shown to be possibly associated with cancer risk. The aim of this meta-analysis was to systematically evaluate this association.

Methods

Studies were selected from PubMed, Web of Science, Embase, Google Scholar, Cochrane Library, the Chinese National Knowledge Infrastructure (CNKI), and the Chinese Biomedical Literature Database (CBM) through inclusion and exclusion criteria. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using the random-effects model or fixed-effects model to assess the association between lncRNA polymorphisms and cancer susceptibility. Metaregression and publication bias analyses were also conducted. All analyses were performed using the Stata 12.0 software.

Results

Sixteen articles (covering 13750 cases and 17194 controls) were included in this meta-analysis. A significant association between SNP rs145204276 and gastric cancer risk was observed (del vs. ins: OR = 0.79, 95%CI = 0.72-0.86; del/del vs. ins/ins+del/ins: OR = 0.74, 95%CI = 0.59-0.91; del/ins vs. ins/ins: OR = 0.84, 95%CI = 0.67-1.05). For rs16901904, a decreased cancer risk was observed in three genetic models (C vs. T: OR = 0.79, 95%CI = 0.70-0.90; CC vs. CT+TT: OR = 0.49, 95%CI = 0.37-0.65; CC vs. TT: OR = 0.49, 95%CI = 0.37-0.66). No statistical significance was found in the metaregression analysis. For all of the included SNPs, no publication bias was found in all genotype models.

Conclusions

The rs145204276 SNP in lncRNA GAS5 is likely to be associated with gastric cancer risk, whereas the rs16901904 SNP in lncRNA PCAT-1 bears association with a decreased cancer risk.

Exosomal long non-coding RNA GAS5 suppresses Th1 differentiation and promotes Th2 differentiation via downregulating EZH2 and T-bet in allergic rhinitis

The imbalance of helper T cell (Th) 1/Th2 differentiation is involved in the development of allergic rhinitis (AR). Recent studies reveal the regulatory function of exosomes on Th1/Th2 differentiation. However, the key mediator in exosomes that modulate such response remains unclear. In this study, the expression of long-noncoding RNA GAS5 (LncGAS5) was detected in exosomes which were isolated from AR patient nasal mucus (AR-EXO) and ovalbumin (OVA)-stimulated nasal epithelial cells (OVA-EXO). Th1/Th2 differentiation was induced in naïve CD4⁺ T cells, and the percentage of IFN-γ expressing cells (Th1 cells) and IL-4 expressing cells (Th2 cells) was detected using flow cytometry. The result showed that LncGAS5 was upregulated in AR epithelial samples, AR-EXO, and OVA-EXO. The coincubation of AR-EXO and CD4⁺ T cells suppressed Th1 differentiation and promoted Th2 differentiation, which is mediated by LncGAS5 in AR-EXO. The LncGAS5 in AR-EXO inhibited transcription and expression of EZH2, and it also inhibited T-bet expression at mRNA and protein levels. The gain-of-function and loss-of-function experiments suggested that LncGAS5 mediates Th1/Th2 differentiation partly through downregulating T-bet and EZH2. In summary, our findings demonstrated that LncGAS5 in AR epithelium-derived exosomes is the key mediator in Th1/Th2 differentiation, providing a possible therapeutic target of AR.

Novel Tumor Suppressor lncRNA Growth Arrest-Specific 5 (GAS5) In Human Cancer

Long noncoding RNAs (lncRNAs) play crucial regulatory roles in fundamental biological processes, and deregulations of lncRNAs have been linked to numerous human diseases, especially cancers. Of particular interest in this regard is lncRNA GAS5, which is mainly identified as a tumor suppressor in several cancers. GAS5 was significantly low expressed in multiple cancers and was associated with clinic-pathological characteristics and patient survival, indicating a novel potential diagnostic and prognostic biomarker, and a therapeutic target for cancer. Functionally, GAS5 is involved in cell proliferation, metastasis, invasion, apoptosis, epithelial-mesenchymal transition (EMT), and drug resistance, among others, via multiple molecular mechanisms, such as binding to DNA sequences, forming RNA-DNA triplex complex, triggering or suppressing the expression of genes, binding proteins to form chromatin-modifying complex, which activates or represses gene expression, and acting as miRNA sponge to suppress miRNA expression, leading to regulation of miRNA target genes. This review provides an overview of the current state of knowledge and role of GAS5 in clinical relevance, biological functions and molecular mechanisms underlying the dysregulation of expression and function of GAS5 in cancer. Finally, the potential prospective role as diagnostic and prognostic biomarker and therapeutic target in cancer is discussed.

Long noncoding RNA GAS5 does not regulate HBV replication

Hepatitis B virus (HBV) infection remains a severe health burden worldwide. Emerging long noncoding RNAs (lncRNAs) are hijacked to enhance virus replication or employed by the host to stimulate immune responses to clear the virus. LncRNA growth arrest-specific transcript 5 (GAS5) can regulate RNA virus by suppressing the replication of both hepatitis C virus and human immunodeficiency virus. In this study, we explored the changes of HBV replication by overexpressing or knocking down GAS5 in HepAD38 cell and HepG2 cell transfected with pHBV1.2. We found HBV can induce the expression of GAS5. However, GAS5 had no effect on extracellular HBsAg and HBeAg, nor intracellular HBV RNA and HBV DNA. In addition, GAS5 possessed similar expression levels between stable HBV-producing cell lines and hepatoma cell lines. Furthermore, GAS5 showed no difference between healthy subjects and patients with chronic HBV in multiple GEO microarray data sets by GEO2R analysis. Taken together these results, GAS5 does not modulate the replication of HBV but it inhibits cell proliferation in HepAD38. This provides insights into the possible roles of GAS5 in HBV infection.

MALAT1 gene expression in colorectal cancer and its clinical significance: Data mining based on multiple gene expression databases

BACKGROUND

Colorectal cancer (CRC) is the most common malignant tumor of the digestive system. Long-chain non-coding RNAs (lncRNAs) play an important role in the occurrence, development, invasion and metastasis of CRC. MALAT1 is a newly discovered lncRNA, and its role in CRC and its relationship with prognosis are not completely clear.

AIM

To explore the differential expression of the lncRNA MALAT1 in CRC and its clinical significance by using bioinformatics data mining technology.

METHODS

BioGPS database was used to analyze the expression of MALAT1 in normal intestinal epithelium. Oncomine was used to meta-analyze the differential expression of MALAT1 in CRC tissue and normal intestinal epithelium tissue, and to analyze the difference of survival time between patients with high and low expression of MALAT1. Protein interaction network analysis was performed based on the STING database to analyze the proteins that potential interact with MALAT1.

RESULTS

The relative expression of MALAT1 in normal colorectal tissues was low. In Oncomine database, there were eight studies on differential expression of CRC, six of which suggested high expression of MALAT1 in CRC and two suggested low expression. The microarray data of 18 CRC and matched normal tissues were compared. The expression of MALAT1 in CRC tissues was significantly higher than that in normal tissues (P = 0.027). There was no significant difference in MALAT1 expression between colon cancer and normal tissues (P = 0.149), but the expression of MALAT1 in rectal cancer was significantly higher than that in normal tissues (P = 1.04 E-5). Kaplan-Meier Plotter analysis demonstrated that the overall survival time of the high and low MALAT1 expression groups was 41.93 months and 52.2 months, respectively, with no significant difference (HR = 0.64, 95%CI: 0.29-1.39, P = 0.25). The possible interaction proteins of MALAT1 were analyzed based on the String database. The results showed that MALAT1 interacts with TP53, SUZ12, CDK4, KDMA, etc. Co-expression analysis showed that MALAT1 protein was co-expressed with EZH2, TP53, SRSF1, and other genes, suggesting that these genes may have similar functions.

CONCLUSION

The expression level of MALAT1 gene in CRC tissues is significantly up-regulated, but there is no correlation between MALAT1 expression and the prognosis of patients. MALAT1 interacts with TP53, SUZ12, CDK4, and KDMA proteins. These interacting proteins include Polycomb-group proteins, cyclin-dependent protein kinase and so on, which are related to gene expression control, transcriptional regulation, and cell division.

The Role of Non-Coding RNA in Congenital Heart Diseases

Cardiovascular development is a complex developmental process starting with the formation of an early straight heart tube, followed by a rightward looping and the configuration of atrial and ventricular chambers. The subsequent step allows the separation of these cardiac chambers leading to the formation of a four-chambered organ. Impairment in any of these developmental processes invariably leads to cardiac defects. Importantly, our understanding of the developmental defects causing cardiac congenital heart diseases has largely increased over the last decades. The advent of the molecular era allowed to bridge morphogenetic with genetic defects and therefore our current understanding of the transcriptional regulation of cardiac morphogenesis has enormously increased. Moreover, the impact of environmental agents to genetic cascades has been demonstrated as well as of novel genomic mechanisms modulating gene regulation such as post-transcriptional regulatory mechanisms. Among post-transcriptional regulatory mechanisms, non-coding RNAs, including therein microRNAs and lncRNAs, are emerging to play pivotal roles. In this review, we summarize current knowledge on the functional role of non-coding RNAs in distinct congenital heart diseases, with particular emphasis on microRNAs and long non-coding RNAs.

Impact of GAS5 genetic polymorphism on prostate cancer susceptibility and clinicopathologic characteristics

Down-regulation of Growth arrest-specific 5 (GAS5) is correlated with enhanced cell proliferation and poorer prognosis of prostate cancer. We aimed to investigate the effect of variant rs145204276 of GAS5 on the prostate cancer susceptibility and clinicopathologic characteristics. In this study, 579 prostate cancer patients who underwent robot-assisted radical prostatectomy and 579 healthy controls were included. The frequency of the allele del of rs145204276 were compared between the patients and the controls to evaluate the impact of tumor susceptibility and the correlation of clinicopathological variables. The results shown that patients who carries genotype ins/del or del/del at SNP rs145204276 showed decreased risk of pathological lymph node metastasis disease (OR=0.545, p=0.043) and risk of seminal vesicle invasion (OR=0.632, p=0.022) comparing to with genotype ins/ins. In the subgroup analysis of age, more significant risk reduction effects were noted over lymph node metastasis disease (OR=0.426, p=0.032) and lymphovascular invasion (OR=0.521, p=0.025). In conclusion, the rs145204276 polymorphic genotype of GAS5 can predict the risk of lymph node metastasis. This is the first study to report the correlation between GAS5 gene polymorphism and prostate cancer prognosis.