GAS5, a long noncoding RNA, contributes to annulus fibroblast osteogenic differentiation and apoptosis in intervertebral disk degeneration via the miR-221-3p/SOX11 axis

miR-221-3p has been reported to attenuate the osteogenic differentiation of annulus fibrosus cells (AFs), which has been implicated in intervertebral disk degeneration (IVDD) development. This study aimed to elucidate miR-221-3p's role in osteogenic differentiation and apoptosis of AFs in an IVDD model. After successfully establishing an IVDD rat model by annulus fibrosus needle puncture, AFs were isolated. Bioinformatics, dual-luciferase reporter, and AGO2-RNA immunoprecipitation (RIP) assays predicted and confirmed the potential miR-221-3p lncRNA and gene target. Functional analyses were performed after AF transfection to explore the roles of the identified lncRNA and gene. Western blotting, Alkaline phosphatase (ALP), and Alizarin red and TUNEL staining were performed to investigate AF apoptosis and osteogenic differentiation with different transfections. Compared with AFs isolated from sham rats, IVDD-isolated Afs exhibited stronger osteogenic potential and higher apoptosis rates accompanied by miR-221-3p downregulation. The growth arrest-specific transcript 5 (GAS5) was identified as miR-221-3p's target lncRNA, which was highly expressed in IVDD. GAS5 overexpression facilitated AF apoptosis and osteogenic differentiation, whereas silencing GAS5 had the opposite effect. SRY box-related11 (SOX11) was identified as a downstream miR-221-3p target gene in IVDD. GASS silencing-induced suppression of AF apoptosis and osteogenic differentiation could be reversed by SOX11 overexpression. Our findings uncovered a lncRNA GAS5/miR-221-3p/SOX11 axis in Afs under IVDD, which may help implement novel IVDD therapeutic strategies.

Electroacupuncture Promotes Nerve Regeneration and Functional Recovery Through Regulating lncRNA GAS5 Targeting miR-21 After Sciatic Nerve Injury

Although the benefits of electroacupuncture (EA) for peripheral nerve injury (PNI) are well accepted in clinical practice, the underlying mechanism remains incompletely elucidated. In our study, we observed that EA intervention led to a reduction in the expression of the long non-coding RNA growth-arrest-specific transcript 5 (GAS5) and an increased in miR-21 levels within the injured nerve, effectively promoting functional recovery and nerve regeneration following sciatic nerve injury (SNI). In contrast, administration of adeno-associated virus expressing GAS5 (AAV-GAS5) weakened the therapeutic effect of EA. On the other hand, both silencing GAS5 and introducing a miR-21 mimic prominently enhanced the proliferation activity and migration ability of Schwann cells (SCs), while also inhibiting SCs apoptosis. On the contrary, inhibition of SCs apoptosis was found to be mediated by miR-21. Additionally, overexpression of GAS5 counteracted the effects of the miR-21 mimic on SCs. Moreover, SCs that transfected with the miR-21 mimic promoted neurite growth in hypoxia/reoxygenation-induced neurons, which might be prevented by overexpressing GAS5. Furthermore, GAS5 was found to be widely distributed in the cytoplasm and was negatively regulated by miR-21. Consequently, the targeting of GAS5 by miR-21 represents a potential mechanism through which EA enhances reinnervation and functional restoration following SNI. Mechanistically, the GAS5/miR-21 axis can modulate the proliferation, migration, and apoptosis of SCs while potentially influencing the neurite growth of neurons.

LncRNA GAS5 Attenuates Cardiac Electrical Remodeling Induced by Rapid Pacing via the miR-27a-3p/HOXa10 Pathway

Previous studies indicated long non-coding RNAs (lncRNAs) participated in the pathogenesis of atrial fibrillation (AF). However, little is known about the role of lncRNAs in AF-induced electrical remodeling. This study aimed to investigate the regulatory effect of lncRNA GAS5 (GAS5) on the electrical remodeling of neonatal rat cardiomyocytes (NRCMs) induced by rapid pacing (RP). RNA microarray analysis yielded reduced GAS5 level in NRCMs after RP. RT-qPCR, western blot, and immunofluorescence yielded downregulated levels of Nav1.5, Kv4.2, and Cav1.2 after RP, and whole-cell patch-clamp yielded decreased sodium, potassium, and calcium current. Overexpression of GAS5 attenuated electrical remodeling. Bioinformatics tool prediction analysis and dual luciferase reporter assay confirmed a direct negative regulatory effect for miR-27a-3p on lncRNA-GAS5 and HOXa10. Further analysis demonstrated that either miR-27a-3p overexpression or the knockdown of HOXa10 further downregulated Nav1.5, Kv4.2, and Cav1.2 expression. GAS5 overexpression antagonized such effects in Nav1.5 and Kv4.2 but not in Cav1.2. These results indicate that, in RP-treated NRCMs, GAS5 could restore Nav1.5 and Kv4.2 expression via the miR-27a-3p/HOXa10 pathway. However, the mechanism of GAS5 restoring Cav1.2 level remains unclear. Our study suggested that GAS5 regulated cardiac ion channels via the GAS5/miR-27a-3p/HOXa10 pathway and might be a potential therapeutic target for AF.

RBM38 Reverses Sorafenib Resistance in Hepatocellular Carcinoma Cells by Combining and Promoting lncRNA-GAS5

BACKGROUND

Hepatocellular carcinoma (HCC) is a life-threatening human malignancy and the fourth leading cause of cancer-related deaths worldwide. Patients with HCC are often diagnosed at an advanced stage with a poor prognosis. Sorafenib is a multikinase inhibitor used as the first-line treatment for patients with advanced HCC. However, acquired resistance to sorafenib in HCC leads to tumor aggression and limits the drug's survival benefits; the underlying molecular mechanisms for this resistance remain unclear.

METHODS

This study aimed to examine the role of the tumor suppressor RBM38 in HCC, and its potential to reverse sorafenib resistance. In addition, the molecular mechanisms underlying the binding of RBM38 and the lncRNA GAS5 were examined. The potential involvement of RBM38 in sorafenib resistance was examined using both in vitro and in vivo models. Functional assays were performed to assess whether RBM38: binds to and promotes the stability of the lncRNA GAS5; reverses the resistance of HCC to sorafenib in vitro; and suppresses the tumorigenicity of sorafenib-resistant HCC cells in vivo.

RESULTS

RBM38 expression was lower in HCC cells. The IC₅₀ value of sorafenib was significantly lower in cells with RBM38 overexpression than in control cells. RBM38 overexpression improved sorafenib sensitivity in ectopic transplanted tumors and suppressed the growth rate of tumor cells. RBM38 could bind to and stabilize GAS5 in sorafenib-resistant HCC cells. In addition, functional assays revealed that RBM38 reversed sorafenib resistance both in vivo and in vitro in a GAS5-dependent manner.

CONCLUSIONS

RBM38 is a novel therapeutic target that can reverse sorafenib resistance in HCC by combining and promoting the lncRNA GAS5.

lncRNA GAS5 suppression of the malignant phenotype of ovarian cancer via the miR-23a-WT1 axis

Background

Growth arrest-specific 5 (GAS5) is a long noncoding RNA (lncRNA) that regulates cell viability. GAS5 lncRNA has been shown to decrease colorectal and breast cancer carcinogenesis. Although the function and mechanisms related to lncRNA GAS5 in the development of ovarian cancer (OC) remains unclear. The goal of this study was to clarify the essential functions of lncRNA GAS5 in regulating OC progression and its underlying mechanism.

Methods

Relative levels of lncRNA GAS5 in OC and normal ovarian tissues were identified by quantitative real-time polymerase chain reaction (qRT-PCR). The regulatory effects of lncRNA GAS5 on the proliferation and apoptosis of SK-OV-3 cells were evaluated. Moreover, bioinformatics tools were used to predict a novel target [microRNA (miRNA)] of lncRNA GAS5. To explore the key functions of the lncRNA GAS5/miRNA-23a/WT1 regulatory loop in mediating OC progression, we performed functional experiments and a dual-luciferase reporter (DLR) gene assessment.

Results

Downregulation of lncRNA GAS5 was found in tissues of OC, which was positively correlated with a poor prognosis. In addition, SK-OV-3 cells with a lower expression of lncRNA GAS5 and accelerated cancer cell migration demonstrated a lower percentage of apoptosis in in vitro experiments. It was demonstrated that lncRNA GAS5 acts as a molecular sponge for miR-23a in OC cells. Additionally, WT1 was detected as a miR-23a target gene in OC cells, and through sponging miR-23a, lncRNA GAS5 positively regulated WT1 expression. Rescue tests demonstrated that enhancing the outputs of the miR-23a-WT1 axis reversed the impacts of lncRNA GAS5 silencing on cell proliferation and apoptosis in OC.

Conclusions

The lncRNA GAS5/miR-23a/WT1 cascade was found participate in the progression of OC. lncRNA GAS5 also decreases OC progression by upregulating WT1 and attenuating miR-23a, suggesting that it could be an advantageous therapeutic target for OC intervention.

The m6A demethylase FTO promotes renal epithelial-mesenchymal transition by reducing the m6A modification of lncRNA GAS5

BACKGROUND

Renal interstitial fibrosis (RIF) is the main pathological change of a variety of chronic kidney diseases (CKD). Epigenetic modifications of fibrosis-prone genes regulate RIF progression. This study aimed to investigate long non-coding RNA (lncRNA) N6-methyladenosine (m⁶A) modification and its role in regulating RIF progression.

METHODS

Unilateral ureteral occlusion (UUO) was employed to construct the RIF in vivo model; and TGF-β1-treated HK-2 and HKC-8 cells were used for in vitro experiments. The mRNA and protein expressions were assessed using qRT-PCR and western blot. The proliferation and migration were evaluated by EdU assay and transwell assay, respectively. In addition, levels of inflammatory cytokines were determined by ELISA assay and qRT-PCR. Moreover, lncRNA GAS5 m⁶A level was detected using Me-RIP assay. HE and Masson staining were employed to evaluate fibrotic lesions of the kidney.

RESULTS

FTO expression was elevated in HK-2 and HKC-8 cells after TGF-β1 treatment and mouse kidney tissue following UUO, and lncRNA GAS5 was downregulated. LncRNA GAS5 overexpression or FTO silencing suppressed TGF-β1-induced the increase of EMT-related proteins (Vimentin, Snail and N-cadherin) and inflammatory cytokines (IL-6, IL-1β and TNF-α) levels in HK-2 cells. FTO suppressed lncRNA GAS5 expression by reducing the m6A modification of lncRNA GAS5. Additionally, FTO knockdown could suppress EMT process and inflammation response induced by TGF-β1 and UUO in vitro and in vivo. As expected, FTO knockdown abrogated the promotion effects of lncRNA GAS5 silencing on TGF-β1-induced EMT process and inflammation response in HK-2 and HKC-8 cells.

CONCLUSION

FTO promoted EMT process and inflammation response through reducing the m⁶A modification of lncRNA GAS5.

Histone demethylase KDM3C regulates the lncRNA GAS5-miR-495-3p-PHF8 axis in cardiac hypertrophy

Cardiac hypertrophy (CH) is a pathological phenotype of cardiomyopathy. Epigenetic modification is a mechanism associated with CH. Our study here investigated the histone demethylase KDM3C in relation to epigenetic regulation in CH. We found that KDM3C mRNA silencing alleviated CH, as evidenced by reduced ANP, BNP, and β-MHC mRNAs, increased α-MHC mRNA, decreased cell surface area, and reduced cellular protein/DNA ratios. Specifically, KDM3C upregulated miR-200c-3p expression through demethylation of H3K9me2, leading to enhanced binding of miR-200c-3p to GAS5 and suppression of GAS5 expression; these effects then led to reduced binding of GAS5 to miR-495-3p, increased miR-495-3p expression, and repression of PHF8 transcription. Through these mechanisms, our data indicate that KDM3C-dependent epigenetic modification promotes CH.

Gas5 inhibition promotes the axon regeneration in the adult mammalian nervous system

Neurons in the peripheral nervous system (PNS) have robust regenerative capacity after axon injury, but the regenerative capacity is generally absent in the neurons of the central nervous system (CNS) in mammals. Increasing evidence highlighted the pivotal roles of long-noncoding RNAs (lncRNAs) in development and disease, but the role of LncRNA in triggering the regenerative capacity in CNS and PNS is not well studied. Here, we reported that lncRNA Gas5 is a suppressor for axon regeneration. Bioinformatics analysis shows that Gas5 is age-dependent up-regulated during DRG neurons development and down-regulated after sciatic nerve injury. In vitro, inhibiting the expression of Gas5 promotes the neurite growth of DRG neurons both in mice and rats. Consistently, Gas5 overexpression inhibits axon growth of mice DRG neurons. In vivo, Gas5 knockout(Gas5-/-) mice display enhanced nerve regeneration ability after sciatic nerve injury. RNA pull-down analysis indicates that Gas5 can interacts with soluble Vimentin, which is essential for peripheral nerve development and regeneration. Vimentin knockdown reverses the Gas5 silence-regulated axon pro-regeneration demonstrating that the function of Gas5 depending on Vimentin. Besides, inhibition of Gas5 expression can also enhance optic nerve regeneration indicating a potential pro-regenerative ability of Gas5 silence in CNS. Our study for the first time provides direct evidence in vivo that lncRNA plays a role in regulating central axon regrowth and Gas5 might be a novel therapeutic target for axon regeneration in both PNS and CNS.

LncRNA GAS5 promotes epilepsy progression through the epigenetic repression of miR-219, in turn affecting CaMKIIγ/NMDAR pathway

It has been widely reported that dysregulated long-chain noncoding RNAs (lncRNAs) are closely associated with epilepsy. This study aimed to probe the function of lncRNA growth arrest-specific 5 (GAS5), microRNA (miR)-219 and Calmodulin-dependent protein kinase II (CaMKII)γ/N-methyl-D-aspartate receptor (NMDAR) pathway in epilepsy. Epileptic cell and animal models were constructed using magnesium deficiency treatment and diazepam injection, respectively. GAS5 and miR-219 expressions in epileptic cell and animal models were determined using qRT-PCR assay. The protein levels of CaMKIIγ, NMDAR and apoptosis-related proteins levels were assessed by western blot. Cell counting kit-8 (CCK-8) assay was employed to determine cell proliferation. Besides, TNFα, IL-1β, IL-6 and IL-8 levels were analyzed using enzyme-linked immunosorbent assay (ELISA). Furthermore, cell apoptosis was evaluated using TUNEL staining and flow cytometric analysis. Finally, the binding relationship between GAS5 and EZH2 was verified using RIP and ChIP assay. Our results revealed that GAS5 was markedly upregulated in epileptic cell and animal models, while miR-219 was down-regulated. GAS5 knockdown dramatically increased cell proliferation of epileptic cells, whereas suppressed inflammation and the apoptosis. Furthermore, our results showed that GAS5 epigenetically suppressed transcriptional miR-219 expression via binding to EZH2. miR-219 mimics significantly enhanced cell proliferation of epileptic cells, while inhibited inflammation and the apoptosis, which was neutralized by CaMKIIγ overexpression. Finally, miR-219 inhibition reversed the effects of GAS5 silence on epileptic cells, which was eliminated by CaMKIIγ inhibition. In conclusion, GAS5 affected inflammatory response and cell apoptosis of epilepsy via inhibiting miR-219 and further regulating CaMKIIγ/NMDAR pathway (See graphic summary in Supplementary Material).

Long non-coding RNA GAS5 contributes to the progression of nonalcoholic fatty liver disease by targeting the microRNA-29a-3p/NOTCH2 axis

Long non-coding RNAs (lncRNAs) have been widely recognized as critical players in the development of nonalcoholic fatty liver disease (NAFLD), one of the most prevalent liver diseases globally. In this study, we established a HFD-induced NAFLD mouse model and explored the role of lncRNA GAS5 in NAFLD progression and its possible underlying mechanisms. We showed that NAFLD activity score was elevated in the HFD mice. GAS5 knockdown attenuated HFD-induced hepatic steatosis and lipid accumulation and reduced NAFLD activity score in HFD mice. In addition, GAS5 knockdown reduced serum triglyceride cholesterol levels and inhibited alanine aminotransferase and aspartate aminotransferase activities in HFD mice. Moreover, GAS5 overexpression enhanced NOTCH2 levels in liver cells and promoted NAFLD progression by sponging miR-29a-3p in vivo. Furthermore, miR-29a-3p inhibited NAFLD progression by targeting NOTCH2 in vivo. Overall, our results indicated that GAS5 acts as a sponge of miR-29a-3p to increase NOTCH2 expression and facilitate NAFLD progression by targeting the miR-29a-3p/NOTCH2 axis and demonstrated a new GAS5-mediated mechanism underlying NAFLD development, suggesting that GAS5 could be a potential therapeutic target of NAFLD.

Abbreviations: Alanine aminotransferase: ALT; Aspartate aminotransferase: AST; Enzyme linked immunosorbent assay: ELISA; Hepatocellular carcinoma: HCC; High-fat diet: HFD; Long non-coding RNA: Lnc RNA; Long non-coding RNA GAS5: GAS5; MicroRNAs: MiRNAs; Nonalcoholic fatty liver disease: NAFLD; Quantitative reverse transcription PCRs: RT-qPCRs; siRNA negative control: si-NC; Total cholesterol: TC; Triglyceride: TG

LncRNA GAS5 positively regulates IL-10 expression in patients with generalized myasthenia gravis

INTRODUCTION

LncRNA growth arrest-specific transcript 5 (GAS5) has been proven to be involved in autoimmune diseases. Rheumatoid arthritis is a type of autoimmune disease that may affect myasthenia gravis (MG) patients. However, its direct role in MG is unknown.

METHODS

Our study included 62 generalized MG patients. GAS5 expression was analyzed with real-time quantitative RT-PCR (qRT-PCR). The interaction between GAS5 and interleukin 10 (IL-10) was explored in overexpressed cells using real time quantitative polymerase chain reactions (RT-qPCRs) and western blot. The correlation of GAS5 and IL-10 was analyzed using Pearson's correlation analysis. The diagnostic value of GAS5 for MG was analyzed using receiver operating characteristic (ROC) curve analysis.

RESULTS

GAS5 and IL-10 mRNA levels in peripheral blood mononuclear cells (PBMCs) were significantly lower in MG patients than healthy controls. Downregulated GAS5 effectively distinguished MG patients from healthy controls. GAS5 expression was positively correlated with IL-10 expression in both MG patients and healthy controls. GAS5 overexpression significantly upregulated IL-10 expression in PBMCs derived from both MG patients and healthy controls.

CONCLUSION

LncRNA GAS5 may improve generalized MG by positively regulating IL-10 expression.

lncRNA GAS5 suppresses rheumatoid arthritis by inhibiting miR-361-5p and increasing PDK4

Rheumatoid arthritis (RA) is an inflammatory disease that causes hyperplasia of synovial tissue and cartilage destruction. This research was to investigate the effects of lncRNA GAS5/miR-361-5p/PDK4 on rheumatoid arthritis. By qRT-PCR, GAS5 and PDK4 were found to be overexpressed in synovial tissue, fibroblast-like synoviocytes of RA patients and LPS-induced chondrocytes, while the miR-361-5p expression was significantly reduced. GAS5 overexpression resulted in a decrease in the proliferation and Bcl-2 protein expression, and an increase in the Bax protein level. On the contrary, miR-361-5p sponged by GAS5 could accelerate chondrocyte proliferation, inhibit apoptosis. PDK4 targeted by miR-361-5p could inhibit RA, and partially eliminated the effect of miR-361-5p on RA. Our study suggested that GAS5 suppressed RA by competitively adsorbing miR-361-5p to modulate PDK4 expression.

LncRNA GAS5 Competitively Combined With miR-21 Regulates PTEN and Influences EMT of Peritoneal Mesothelial Cells via Wnt/β-Catenin Signaling Pathway

Objective

Epithelial-mesenchymal transition (EMT) is an important factor leading to peritoneal fibrosis (PF) in end-stage renal disease (ESRD) patients. The current research aimed to evaluate the effect of long non-coding RNA growth arrest-specific 5 (lncRNA GAS5) in human peritoneal mesothelial cells (HPMCs) EMT and explore the potential molecular mechanisms.

Materials and Methods

HPMCs were cultured under control conditions or with high glucose (HG). The cells were then treated with lncRNA GAS5, lncRNA GAS5 siRNA, with or without miR-21 inhibitor and PTEN transfection. Expression of lncRNA GAS5, miR-21, α-SMA, Vimentin, E-cadherin, phosphatase and tensin homolog deleted on chromosome ten (PTEN), Wnt3a, and β-catenin were measured by real time PCR and Western blotting. Bioinformatics analyses were used to test the specific binding sites between the 3' UTR of the PTEN gene, miR-21, and lncRNA GAS5. Rescue experiments were performed to confirm the lncRNA GAS5/miR-21/PTEN axis in HPMC EMT.

Results

We found that HG-induced EMT decreased lncRNA GAS5 and that overexpression of lncRNA GAS5 can attenuate EMT in HPMCs. In addition, lncRNA GAS5 regulated HG-induced EMT through miR-21/PTEN. Cotransfection of miR-21 inhibitors remarkably increased PTEN expression and attenuated EMT in lncRNA GAS5 knockdown HPMCs. Moreover, rescue experiments showed that overexpression of PTEN attenuated the EMT effects of lncRNA GAS5 siRNA in HPMCs. We also confirmed that the Wnt/β-catenin pathway was stimulated in lncRNA GAS5/miR-21/PTEN-mediated EMT.

Conclusion

Our research showed that lncRNA GAS5 competitively combined with miR-21 to regulate PTEN expression and influence EMT of HPMCs via the Wnt/β-catenin signaling pathway. This study provides novel evidence that lncRNA GAS5 may be a potential therapeutic target for HPMC EMT.

Knockdown of long noncoding RNA growth arrest-specific transcript 5 regulates forkhead box O3 to inhibit lipopolysaccharide-induced human bronchial epithelial cell pyroptosis

Pyroptosis is a novel proinflammatory programmed cell death process. This study was designed to investigate the functional mechanisms of long noncoding RNA growth arrest-specific transcript 5 (lncRNA GAS5) on lipopolysaccharide (LPS)-induced human bronchial epithelial cell (HBEC) pyroptosis. LPS was used to induce pyroptosis in HBECs, followed by the detection of the expression of GAS5, forkhead box O3 (FOXO3), and nuclear factor E2-related factor 2/heme oxygenase 1 (Nrf2/HO-1) signaling pathway-related factors. Cell viability was evaluated using CCK-8 assay, lactate dehydrogenase (LDH) release was assessed by LDH assay kit and caspase-1 activity by flow cytometry. Furthermore, expression of NOD-like receptor family pyrin domain containing 3 and pyroptosis-related proteins was evaluated using Western blot analysis, while enzyme-linked immunosorbent assay was used to determine the levels of inflammatory factors. The interaction between GAS5 and FOXO3 was confirmed using bioinformatic prediction, RNA immunoprecipitation assay, RNA pull-down, and dual-luciferase reporter gene assay. Treatment of HBECs with LPS upregulated the expression of GAS5 and FOXO3, resulting in the inactivation of the Nrf2/HO-1 signaling pathway. On the other hand, inhibition of both GAS5 and FOXO3 promoted cell viability, reduced LDH release, pyroptosis, and inflammatory response in LPS-induced HBECs. Furthermore, FOXO3 could interact with GAS5, while FOXO3 overexpression reversed the inhibitory effect of GAS5 knockdown on cell pyroptosis. Thus, mechanistically, inhibition of FOXO3 activates the Nrf2/HO-1 pathway to suppress LPS-induced pyroptosis in HBECs. This study revealed that GAS5 knockdown attenuates FOXO3 expression thereby activating the Nrf2/HO-1 pathway to inhibit LPS-induced pyroptosis in HBECs. These findings may contribute to identifying novel targets that inhibit pyroptosis in HBECs.

LncRNA GAS5 as miR-26a-5p Sponge Regulates the PTEN/PI3K/Akt Axis and Affects Extracellular Matrix Synthesis in Degenerative Nucleus Pulposus Cells in vitro

The role of lncRNA growth arrest specific 5 (GAS5) in degenerative nucleus pulposus cell (NPC) apoptosis has been reported, but the mechanism of GAS5 in extracellular matrix (ECM) synthesis in intervertebral disc degeneration (IDD) remains unknown. We aimed to investigate the mechanism of GAS5 in ECM synthesis in degenerative NPCs. GAS5 expression was measured in degenerative NPCs (CP-H170) and normal NPCs (CP-H097). siRNA-mediated GAS5 knockdown was transfected to NPCs to detect cell viability and the expression of ECM-related genes (Collagen II, aggrecan, Collagen I, and MMP-3). Subcellular localization of GAS5 was analyzed. The downstream gene and pathway of GAS5 in degenerative NPCs were explored. As our results indicated, lncRNA GAS5 was upregulated in degenerative NPCs. Silencing GAS5 improved the viability of degenerative NPCs and increased ECM synthesis. GAS5 was mainly located in the cytoplasm of NPCs. LncRNA GAS5 sponged miR-26a-5p to regulate PTEN. Overexpression of miR-26a-5p promoted ECM synthesis in degenerative NPCs. Akt inhibitor LY294002 reversed the promotion of silencing GAS5 on ECM synthesis of degenerative NPCs. In conclusion, lncRNA GAS5 sponged miR-26a-5p to upregulate PTEN and inhibit the PI3K/Akt pathway, thus inhibiting ECM synthesis of degenerative NPCs.

lncRNA GAS5 regulates angiogenesis by targeting miR‑10a‑3p/VEGFA in osteoporosis

Osteoporosis is a severe bone disease commonly occurring in older males and postmenopausal females. Previous studies have shown that long non‑coding (lnc)RNA growth arrest‑specific 5 (GAS5) serves an important role in osteoporosis. However, its role is unclear and requires further exploration. The relative expression levels of GAS5 and miR‑10a‑3p in the serum samples of patients with osteoporosis, as well as the relative expression levels of GAS5, microRNA (miR)‑10a‑3p and vascular endothelial growth factor A (VEGFA) mRNA in osteoblasts, were detected by reverse transcription‑quantitative PCR. ELISA and western blotting were used to detect the expression levels of VEGFA. A Matrigel angiogenesis test was used to assess the effects on angiogenesis. RNA binding interactions between GAS5/miR‑10a‑3p and miR‑10a‑3p/VEGFA were evaluated using dual‑luciferase reporter assays. Furthermore, the effects of the GAS5/miR‑10a‑3p/VEGFA axis were investigated via ELISA, western blotting and Matrigel angiogenesis. GAS5 was significantly downregulated and miR‑10a‑3p was upregulated in patients with osteoporosis. Overexpression of GAS5 promoted angiogenesis. GAS5 acted as a sponge of miR‑10a‑3p; VEGFA was a target gene of miR‑10a‑3p. GAS5 induced angiogenesis by inhibiting miR‑10a‑3p and enhancing VEGFA expression. These results indicated that GAS5 overexpression increased angiogenesis by inhibiting miR‑10a‑3p, promoting the expression of VEGFA. The present study revealed a novel mechanism and provided novel targets for the clinical treatment of osteoporosis.

LncRNA GAS5 modulates the progression of non-small cell lung cancer through repressing miR-221-3p and up-regulating IRF2

BACKGROUND

Long non-coding RNA growth arrest specific 5 (GAS5) is a regulator in non-small cell lung cancer (NSCLC) progression. Nonetheless, the mechanism by which GAS5 exerts its biological function in NSCLC cells remains unclear.

METHODS

GAS5, miR-221-3p relative expression levels in NSCLC tissues and cells were examined by qPCR. After gain-of-function and loss-of-function models were established, the viability of H1299 and A549 cells were examined by CCK-8 and EdU assays. Cell migration and invasion were examined by the Transwell experiment. The binding sequence of GAS5 for miR-221-3p was confirmed by the dual-luciferase reporter gene experiment. The regulatory function of GAS5 and miR-221-3p on IRF2 was investigated by Western blot.

RESULTS

GAS5 expression was down-modulated in NSCLC tissues and cell lines. GAS5 overexpression restrained the proliferation, migration and invasion of NSCLC cells, while miR-221-3p, which was targeted and negatively modulated by GAS5, worked oppositely. Restoration of miR-221-3p markedly reversed the effects of GAS5 on NSCLC cells. Additionally, GAS5 increased IRF2 expression in NSCLC cells by repressing miR-221-3p.

CONCLUSIONS

GAS5 blocks the progression of NSCLC partly via increasing IRF2 expression level via repressing miR-221-3p.

Silencing of Long Noncoding RNA Growth Arrest-Specific 5 Alleviates Neuronal Cell Apoptosis and Inflammatory Responses Through Sponging microRNA-93 to Repress PTEN Expression in Spinal Cord Injury

A secondary injury induced by a spinal cord injury (SCI) remains the main cause of devastating neural dysfunction; therefore, it has been the subject of focused research for many years. Long noncoding RNA (lncRNA) has been found to participate in the SCI process, and this finding presents a high potential for diagnosis and treatment; however, the role of lncRNA in a secondary injury induced by SCI remains unclear. The aim of this study was to investigate the regulatory effect of lncRNA growth arrest–specific transcript 5 (GAS5) in secondary injury during SCI. The SCI mice model and hypoxic cellular model were established to research the roles of lncRNA GAS5 during SCI. Reverse transcription quantitative polymerase chain reaction (qRT-PCR) was conducted to determine the expression levels of microR-93 (miR-93) and lncRNA GAS5. Western blot analysis of the apoptosis regulator protein and terminal deoxynucleotidyl transferase dUTP nick end labeling assay was conducted to evaluate neuron cell apoptosis. Basso, Beattie, and Bresnahan (BBB) scores were calculated to assess neurological function. Flow cytometry was used to determine neuron cell apoptosis. The associations among GAS5, miR-93, and the phosphatase and tensin homolog (PTEN) were disclosed using RNA immunoprecipitation (RIP) assay, RNA pulldown assay, and dual-luciferase reporter assay. QRT-PCR demonstrated that GAS5 was significantly upregulated in both the SCI mice and hypoxic cellular models. GAS5 knockdown suppressed neuron cell apoptosis and inflammatory response in the SCI mice model. Further studies have indicated that GAS5 functions as a competing endogenous RNA (ceRNA) by sponging miR-93 in neuronal cells. In addition, PTEN was a target of miR-93, and GAS5 knockdown exhibited its anti-apoptotic and anti-inflammatory effects through the miR-93/PTEN axis. These findings suggest that the GAS5/miR-93/PTEN axis may be a promising therapeutic target for SCI.

Long non-coding RNA GAS5 knockdown facilitates proliferation and impedes apoptosis by regulating miR-128-3p/FBLN2 axis in ox-LDL-induced THP-1 cells

BACKGROUND

Long non-coding RNAs (lncRNAs) are found to involve in modulating the development of atherosclerosis (AS). But the molecular mechanism of lncRNA growth-arrest specific transcript 5 (GAS5) in AS is not fully understood.

METHODS

QRT-PCR was performed to measure the abundances of GAS5, miR-128-3p and fibulin 2 (FBLN2). Oxidized low-density lipoprotein (ox-LDL)-treated THP-1 cells were employed as cell models of AS. The cell proliferation and apoptosis were analyzed using CCK-8 and Flow cytometry assays, respectively. Levels of all protein were examined by western blot. The interaction among GAS5, miR-128-3p and FBLN2 was confirmed via dual-luciferase reporter and RNA immunoprecipitation (RIP) assays.

RESULTS

GAS5 was elevated and miR-128-3p was decreased in the serum of patients with AS and ox-LDL-stimulated THP-1 cells. Ox-LDL stimulation inhibited proliferation and induced apoptosis of THP-1 cells. Meanwhile, GAS5 directly targeted miR-128-3p and inversely modulated its expression. Importantly, GAS5 depletion facilitated cell proliferation and impaired apoptosis in ox-LDL-induced THP-1 cells. Additionally, GAS5 augmented FBLN2 expression through sponging miR-128-3p, and miR-128-3p facilitated proliferation and retarded apoptosis of ox-LDL-induced THP-1 cells by targeting FBLN2.

CONCLUSION

GAS5 knockdown promoted the growth of ox-LDL-induced THP-1 cells through down-modulating FBLN2 and increasing miR-128-3p, suggesting the potential value of GAS5 for treatment of AS.

DNMT1 Methylation of LncRNA GAS5 Leads to Cardiac Fibroblast Pyroptosis via Affecting NLRP3 Axis

Cell death and inflammation play critical roles in cardiac fibrosis. During the fibrosis process, inflammation and tissue injury were triggered; however, the mechanisms initiating cardiac fibrosis and driving fibroblast pyroptosis remained largely unknown. In this study, we identified long non-coding RNA (LncRNA)-GAS5 as the key onset of cardiac fibroblast pyroptosis and cardiac fibrosis. Here, we detected ISO-induced cardiac fibrosis models and cardiac fibroblast pyroptosis model by stimulating with LPS. We found that the expression of pyroptosis-related proteins such as caspase 1, NLRP3, and DNMT1 was increased in cardiac fibrosis tissue, while the expression of GAS5 was decreased. The overexpressing of LncRNA GAS5 was shown to increase and inhibit cardiac fibroblast pyroptosis, as well as attenuate caspase 1 and NLRP3 expression in cardiac fibroblast. However, the silencing of GAS5 was also observed; it shows the opposite situation. Furthermore, further studies revealed that treatment of DNMT inhibitor, 5-aza-2-deoxycytidine, or downregulation of DNMT1 led to increased GAS5 expression by reversion of promoter hypermethylation in cardiac fibroblast. Importantly, we have demonstrated that DNMT1 methylation of LncRNA GAS5 leads to cardiac fibroblast pyroptosis via affecting NLRP3 axis. Our findings indicate a new regulatory mechanism for cardiac fibroblast pyroptosis under LPS stress, providing a novel therapeutic target for cardiac fibrosis. Graphical Abstract.

Qingda granule exerts neuroprotective effects against ischemia/reperfusion-induced cerebral injury via lncRNA GAS5/miR-137 signaling pathway

Background: Ischemic stroke is the second leading cause of death and disability worldwide, which needs to develop new pharmaceuticals for its prevention and treatment. Qingda granule (QDG), a traditional Chinese medicine formulation, could improve angiotensin II-induced brain injury and decrease systemic inflammation. In this study, we aimed to evaluate the neuroprotective effect of QDG against ischemia/reperfusion-induced cerebral injury and illustrate the potential mechanisms. Methods: The middle cerebral artery occlusion/reperfusion (MCAO/R) surgery in vivo and oxygen-glucose deprivation/reoxygenation (OGD/R) in vitro models were established. Ischemic infarct volume was quantified using magnetic resonance imaging (MRI). Neurobehavioral deficits were assessed using a five-point scale. Cerebral histopathology was determined by hematoxylin-eosin (HE) staining. Neuronal apoptosis was evaluated by TUNEL and immunostaining with NeuN antibodies. The protective effect of QDG on OGD/R-injured HT22 cells was determined by MTT assay and Hoechst 33258 staining. The expression of lncRNA GAS5, miR-137 and apoptosis-related proteins were investigated in MCAO/R-injured rats and in OGD/R-injured HT22 cells using RT-qPCR and western blot analysis. Results: QDG significantly reduced the ischemic infarct volume, which was accompanied with improvements in neurobehavioral deficits. Additionally, QDG significantly ameliorated cerebral histopathological changes and reduced neuron loss in MCAO/R-injured rats. Moreover, QDG improved growth and inhibited apoptosis of HT22 cells injured by OGD/R in vitro. Finally, QDG significantly decreased the expression of lncRNA GAS5, Bax and cleaved caspase3, whereas it increased miR-137 and Bcl-2 expression in MCAO/R-injured rats and in OGD/R-injured HT22 cells. Conclusion: QDG plays a neuroprotective role in ischemic stroke via regulation of the lncRNA GAS5/miR-137 signaling pathway.

LncRNA GAS5 alleviates rheumatoid arthritis through regulating miR-222-3p/Sirt1 signalling axis

INTRODUCTION

Rheumatoid arthritis (RA) is an autoimmune disease that affects millions of people. Fibroblast-like synoviocytes (FLSs) located in rheumatoid panni play a pivotal role in the formation of RA. The long noncoding RNA (lncRNA) GAS5 is reportedly downregulated in rheumatoid arthritis. However, its detailed mechanism in RA remains to be explored. This study investigated the roles and related mechanisms of GAS5 in RA.

METHODS

The expression levels of GAS5, miR-222-3p, and sirtuin 1 (Sirt1) were evaluated by quantitative PCR (qPCR). Cell proliferation was analyzed by CCK-8 and BrdU assays. Cell apoptosis was assessed by flow cytometry and western blotting. Enzyme-linked immunosorbent assay (ELISA) was utilized to evaluate the levels of TNF-α, IL-1β, and IL-6. The interaction between GAS5 or Sirt1 and miR-222-3p was predicted by starBase and validated by dual-luciferase reporter assay.

RESULTS

GAS5 expression was found to be downregulated in the serum samples of RA patients and in RA-FLSs. GAS5 overexpression or the inhibition of miR-222-3p impeded the activity of RA-FLSs by repressing their proliferation and inflammation and by promoting apoptosis. Mechanistically, GAS5 indirectly regulates Sirt1 expression by binding miR-222-3p. Further experiments confirmed that Sirt1 overexpression restored the anti-RA activity of GAS5 under miR-222-3p mimic.

CONCLUSIONS

The miR-222-3p/Sirt1 axis was found to be critical for the function of GAS5 in regulating the proliferation, inflammation, and apoptosis of RA-FLSs. These data indicate GAS5 activation as a potential therapeutic strategy for RA progression.

LncRNA GAS5/miR‑4465 axis regulates the malignant potential of nasopharyngeal carcinoma by targeting COX2

Nasopharyngeal carcinoma is a malignant tumor that not only negatively affects the physical and mental health but also the quality of life of the patients. Growth arrest-specific transcript 5 (GAS5) is a common long-chain non-coding RNA (lncRNA) that has been reported to participate in the development of various cancers. However, the biological functions of lncRNA GAS5 in the occurrence and development of nasopharyngeal carcinoma are elusive. The expression of lncRNA GAS5 in nasopharyngeal carcinoma and normal samples were analyzed. Bioinformatic tool was utilized to predict the potential function of lncRNA in nasopharyngeal carcinoma. Transplanted mice were used for in vivo experiments. We observed that the expression of lncRNA GAS5 was upregulated in nasopharyngeal carcinoma tissues and cells. Down-regulation of lncRNA GAS5 inhibited the proliferation and promoted apoptosis of nasopharyngeal carcinoma cells. The expression of miR-4465 was down regulated in nasopharyngeal carcinoma tissues and cells. LncRNA GAS5 could directly bind to miR-4465 and regulated the expression of miR-4465. It was further confirmed that miR-4465 could directly bind with COX2 and inhibit the expression of COX2. Down-regulation of lncRNA GAS5 suppressed tumor growth, promoted the expression levels of miR-18a-5p and suppressed the expression of COX2 in vivo. LncRNA GAS5 regulated nasopharyngeal carcinoma malignancy through targeting miR-4465 and modulating COX2. The GAS5/miR-4465/COX2 axis in nasopharyngeal carcinoma pathogenesis was confirmed, which would provide a new therapeutic target for nasopharyngeal carcinoma.

Circulating Long Non-Coding RNA GAS5 Is Overexpressed in Serum from Osteoporotic Patients and Is Associated with Increased Risk of Bone Fragility

Osteoporosis (OP) is a multifactorial disorder in which environmental factors along with genetic variants and epigenetic mechanisms have been implicated. Long non-coding RNAs (lncRNAs) have recently emerged as important regulators of bone metabolism and OP aetiology. In this study, we analyzed the expression level and the genetic association of lncRNA GAS5 in OP patients compared to controls. Quantitative RT-PCR analysis of GAS5 was performed on the serum of 56 OP patients and 28 healthy individuals. OP subjects were divided into three groups of analysis: 29 with fragility fractures of lumbar spine (OP_VF), 14 with fragility fractures of femoral neck (OP_FF) and 13 without fractures (OP_WF). Genotyping of the rs145204276 insertion/deletion polymorphism has also been performed by Restriction fragment length polymorphism (RFLP) and direct sequencing analyses. Expression of circulating GAS5 is significantly increased in OP patients compared to controls (p < 0.01), with a statistically higher significance in fractured OP individuals vs. healthy subjects (p < 0.001). No statistically significant change was found in female OP patients; conversely, GAS5 is upregulated in the subgroup of fractured OP women sera (p < 0.01) and in all OP males (p < 0.05). Furthermore, a direct correlation between GAS5 expression level and parathyroid hormone (PTH) concentration was found in OP patients (r = 0.2930; p = 0.0389). Genetic analysis of rs145204276 revealed that the deletion allele was correlated with a higher expression of GAS5 in OP patients (0.22 ± 0.02 vs. 0.15 ± 0.01, ** p < 0.01). Our results suggest circulating GAS5 as a putative biomarker for the diagnosis and prognosis of OP and OP-related fractures.

MiR-663a, regulated by lncRNA GAS5, contributes to osteosarcoma development through targeting MYL9

Osteosarcoma is characterized by high malignancy and high metastasis rate, resulting in high mortality and disability. MiR-663a has been reported in a variety of tumors to promote tumorigenesis. However, miR-663a has not been reported in the pathogenesis of osteosarcoma. Bioinformatics analysis and experiments including real-time quantitative polymerase chain reaction (RT-qPCR), luciferase reporter, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, Western blot, RNA immunoprecipitation, and flow cytometry assay were applied to explore the function and mechanism of miR-663a in MG63, U2OS, Saos-2, SF-86, and hFOB1.19 cells. In this study, we found that miR-663a is highly expressed in osteosarcoma. At the same time, we discovered that miR-663a facilitates cell proliferation and migration, whereas suppresses cell apoptosis in osteosarcoma. Through a series of biological experiments, it was found that miR-663a regulates the cellular process in osteosarcoma by modulating the expression of MYL9. In addition, we also found that long noncoding RNA (lncRNA) GAS5 serves as a molecular sponge for miR-663a and regulates the progression of osteosarcoma via the ceRNA mechanism. We uncover that miR-663a promotes osteosarcoma development through targeting MYL9, which was regulated by lncRNA GAS5.

Association of genetic variants in lncRNA GAS5/miR-21/mTOR axis with risk and prognosis of coronary artery disease among a Chinese population

Background

Allowing for the significance of single nucleotide polymorphisms (SNPs) in reflecting disease risk, this investigation attempted to uncover whether SNPs situated in lncRNA GAS5/miR‐21/mTOR axis were associated with risk and prognosis of coronary heart disease (CHD) among a Chinese Han population.

Methods

Altogether 436 patients with CHD were recruited as cases, and meanwhile, 471 healthy volunteers were included into the control group. Besides, SNPs of GAS5/MIR‐21/mTOR axis were genotyped utilizing mass spectrometry. Chi‐square test was applied to figure out SNPs that were strongly associated with CHD risk and prognosis, and combined effects of SNPs and environmental parameters on CHD risk were evaluated through multifactor dimensionality reduction (MDR) model.

Results

Single nucleotide polymorphisms of GAS5 (ie, rs2067079 and rs6790), MIR‐21 (ie, rs1292037), and mTOR (rs2295080, rs2536, and rs1034528) were associated with susceptibility to CHD, and also Gensini score change of patients with CHD (P < .05). MDR results further demonstrated that rs2067079 and rs2536 were strongly interactive in elevating CHD risk (P < .05), while smoking, rs6790 and rs2295080 showed powerful reciprocity in predicting Gensini score change of patients with CHD (P < .05).

Conclusion

Single nucleotide polymorphisms of lncRNA GAS5/miR‐21/mTOR axis might interact with smoking to regulate CHD risk, which was conducive to diagnosis and prognostic anticipation of CHD.

Expression of the Long Noncoding RNA GAS5 Correlates with Liver Fibrosis in Patients with Nonalcoholic Fatty Liver Disease

BACKGROUND

Advanced liver fibrosis is the most important prognostic factor in nonalcoholic fatty liver disease (NAFLD). The long noncoding RNA (lncRNA), growth arrest-specific transcript 5 (GAS5), is associated with the inhibition of liver fibrogenesis, and its levels are decreased in cirrhotic liver.

METHODS

We analyzed 51 patients with NAFLD, the diagnosis of which was confirmed by liver biopsy. Expression of GAS5 in both the liver and plasma of the patients was analyzed using a quantitative real-time polymerase chain reaction according to the fibrosis stage.

RESULTS

Plasma GAS5 expression was significantly higher in patients with advanced fibrosis than in those without. As the fibrosis progressed, GAS5 expression in plasma increased, with the exception of that in cirrhotic livers. Plasma levels of GAS5 were lower in patients with cirrhosis than in those with advanced fibrosis.

CONCLUSION

Elevated circulating levels of the lncRNA GAS5 are associated with the progression of liver fibrosis prior to the development of cirrhosis.

Long non-coding RNA GAS5 inhibits migration and invasion in gastric cancer via interacting with p53 protein

BACKGROUND

The rapid progress of gastric cancer (GC) is mainly due to metastasis. Long non-coding RNA (lncRNA) GAS5 has been identified as a tumor suppressor in numerous cancers, and its downregulation in GC has already been reported.

AIMS

In this study, we planned to investigate the role of GAS5 in GC metastasis.

METHODS

Gene expressions were detected by qRT-PCR. ISH staining was applied to assess GAS5 level in clinical tissues. Gain-of-function assays were conducted to evaluate the function of GAS5 in GC metastasis. RNA pull down, RIP and cycloheximide assays were performed to confirm the relationship between GAS5 and p53 protein.

RESULTS

GAS5 expression was markedly decreased in GC tissues and cell lines, and its low expression was strongly related to GC metastasis and unsatisfactory prognosis. GAS5 overexpression repressed GC cell migration and invasion by targeting p53. Intriguingly, GAS5 relied on the exon 12 to interact with and stabilize p53 protein.

CONCLUSION

Our data implied that GAS5 is a suppressor in GC metastasis via modulating p53 signaling, suggesting GAS5 as a potential therapeutic target for GC, especially for patients with metastasis.

LncRNA GAS5 enhanced the killing effect of NK cell on liver cancer through regulating miR-544/RUNX3

This study aimed to explore the role of lncRNA GAS5 in the regulation of the killing effect of NK cells on liver cancer. Compared with a control group, lncRNA GAS5, RUNX3, and NCR1 were down-regulated in NK cells of patients with liver cancer, whereas miR-544 expression was up-regulated in NK cells of patients with liver cancer. Activated NK cells had higher IFN-γ level. Knockdown of GAS5 in activated NK cells decreased IFN-γ secretion, NK cell cytotoxicity, the percentage of CD107a+ NK cells, and the apoptosis rate of HepG2 and Huh7 cells. We also proved the interaction of GAS5 and miR-544, and the negative regulation role of GAS5 on miR-544. GAS5 overexpression in activated NK cells increased RUNX3 expression, IFN-γ secretion, the NK cell cytotoxicity, the percentage of CD107a+ NK cells, and the apoptosis rate of HepG2 cells, while miR-544 mimic abolished the promotion effect of GAS5 overexpression. Finally, in vivo experiments indicated an inhibition effect of GAS5 in tumor growth. LncRNA GAS5 overexpression enhances the killing effect of NK cell on liver cancer through regulating miR-544/RUNX3.

The lncRNA-GAS5/miR-221-3p/DKK2 Axis Modulates ABCB1-Mediated Adriamycin Resistance of Breast Cancer via the Wnt/β-Catenin Signaling Pathway

Drug resistance, including adriamycin (ADR)-based therapeutic resistance, is a crucial cause of chemotherapy failure in breast cancer treatment. Acquired chemoresistance has been identified to be closely associated with the overexpression of P-glycoprotein (P-gp/ABCB1). Long non-coding RNA (lncRNA) growth arrest-specific 5 (GAS5) can be involved in carcinogenesis; however, its roles in ABCB1-mediated ADR resistance are poorly understood. In this study, we identified a panel of differentially expressed lncRNAs, mRNAs, and microRNAs (miRNAs) in MCF-7 and MCF-7/ADR cell lines through RNA sequencing (RNA-seq) technologies. GAS5 level was downregulated whereas ABCB1 level was upregulated in the resistant breast cancer tissues and cells. Overexpression of GAS5 significantly enhanced the ADR sensitivity and apoptosis, and it inhibited the efflux function and expression of ABCB1 in vitro, while knockdown of GAS5 had the opposite effects. Further mechanism-related investigations indicated that GAS5 acted as an endogenous “sponge” by competing for miR-221-3p binding to regulate its target dickkopf 2 (DKK2), and then it inhibited the activation of the Wnt/β-catenin pathway. Functionally, GAS5 enhanced the anti-tumor effect of ADR in vivo. Collectively, our findings reveal that GAS5 exerted regulatory function in ADR resistance possibly through the miR-221-3p/DKK2 axis, providing a novel approach to develop promising therapeutic strategy for overcoming chemoresistance in breast cancer patients.

Assessment of lncRNA GAS5, lncRNA HEIH, lncRNA BISPR and its mRNA BST2 as serum innovative non-invasive biomarkers: Recent insights into Egyptian patients with hepatitis C virus type 4

BACKGROUND

Hepatitis C virus (HCV) infection and its consequent complications are undeniably a public health burden worldwide, particularly in Egypt. Emerging evidence suggests that many lncRNAs have relevant roles in viral infections and antiviral responses.

AIM

To investigate the expression profiles of circulating lncRNAGAS5, lncRNAHEIH, lncRNABISPR and mRNABST2 in naïve, treated and relapsed HCV Egyptian patients, to elucidate relation to HCV infection and their efficacy as innovative biomarkers for the diagnosis and prognosis of HCV GT4.

METHODS

One hundred and thirty HCV-infected Egyptian patients and 20 healthy controls were included in this study. Serum lncRNAs and mRNABST2 were measured using quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

Our results indicated that serum lncRNAGAS5 and LncRNABISPR were upregulated, whereas mRNA BST2 and LncRNA HEIH were downregulated in naïve patients. In contrast, HCV patients treated with sofosbuvir and simeprevir; with sofosbuvir and daclatasvir; or with sofosbuvir, daclatasvir and ribavirin exhibited lower levels of lncRNAGAS5 and lncRNABISPR with higher mRNABST2 compared to naïve patients. Notably, patients relapsed from sofosbuvir and simeprevir showed higher levels of these lncRNAs with lower mRNABST2 compared to treated patients. LncRNAGAS5 and lncRNABISPR were positively correlated with viral load and ALT at P < 0.001, whereas mRNABST2 was negatively correlated with viral load at P < 0.001 and ALT at P < 0.05. Interestingly, a significant positive correlation between lncRNA HEIH and AFP was observed at P < 0.001.

CONCLUSION

Differential expression of these RNAs suggests their involvement in HCV pathogenesis or antiviral response and highlights their promising roles in diagnosis and prognosis of HCV.

Long non-coding RNA GAS5 expression in patients with Down syndrome

Trisomy 21, also known as Down Syndrome (DS), is the most common chromosome abnormality and causes intellectual disability. Long non-coding RNA (lncRNA) growth arrest-specific 5 (GAS5), whose differential expression has recently been reported in patients with Klinefelter syndrome, has been addressed to play a role in the development of inflammatory and autoimmune diseases, vascular endothelial cells apoptosis and atherosclerosis, all being common features in patients with DS. Therefore, the aim of this study was to assess the lncRNA GAS5 expression profile in DS patients and in controls. lncRNA GAS5 levels were evaluated by qRT-PCR assay in 23 patients with DS and 23 age-matched controls. A significant lncRNA GAS5 down-regulation was observed in patients with DS by RT-PCR analysis, The RNA sequencing experiments confirmed the qRT-PCR data. LncRNA GAS5 down-expression may play a role in the development of some typical features of the patients with DS and, particularly, in inflammatory and autoimmune diseases.

lncRNA GAS5/miR-452-5p Reduces Oxidative Stress and Pyroptosis of High-Glucose-Stimulated Renal Tubular Cells

BACKGROUND

Diabetic nephropathy (DN) is the leading cause of end-stage renal failure worldwide. lncRNAs are demonstrated to improve the DN by changing the expression of miRNAs. This study was aimed to investigate the effect of lncRNA GAS5/miR-452-5p on the inflammation, oxidative stress and pyroptosis of high-glucose-induced renal tubular cells.

METHODS

HK-2 cells were induced by HG to simulate DN cells. RT-qPCR analysis confirmed the transfection effects and detected the expression of GAS5, NLRP3, caspase1, IL-1β, pro-caspase1, pro-IL-1β, GSDMD-N and miR-452-5p. Western blot analysis determined the protein expression of NLRP3, caspase1, IL-1β, pro-caspase1, pro-IL-1β and GSDMD-N. The expression of GSDMD-N was also verified by immunofluorescence. The levels of TNF-α, IL-6, MCP-1, ROS, MDA and SOD were measured by commercial assay kits, respectively. Dual-luciferase reporter assay indicated that GAS5 could combine with miR-452-5p.

RESULTS

GAS5 expression was decreased in HG-induced HK-2 cells. GAS5 overexpression could decrease the levels of TNF-α, IL-6, MCP-1, ROS and MDA and increase the levels of SOD. Moreover, GAS5 overexpression suppressed the expression of NLRP3, caspase1, IL-1β and GSDMD-N, and the results of immunofluorescence verified the above results. miR-452-5p interference could cause the same changes as GAS5 overexpression for HG-induced HK-2 cells, and GAS5 inhibition could reverse the effect of miR-452-5p interference.

CONCLUSION

GAS5 overexpression inhibited the inflammation, oxidative stress and pyroptosis of HG-induced renal tubular cells by downregulating the expression of miR-452-5p.

Silence of lncRNA GAS5 alleviates high glucose toxicity to human renal tubular epithelial HK-2 cells through regulation of miR-27a

Renal tubular damage caused by persistent high glucose environment has been found to contribute to diabetic nephropathy. This study explored the effects of lncRNA growth arrest-specific 5 (GAS5) on high glucose-stimulated human renal tubular epithelial HK-2 damage, as well as the possible internal molecular mechanism. Viability and apoptosis of HK-2 cells were assessed with the help of CCK-8 assay and Annexin V-FITC/PI staining, respectively. Cell transfection was used to change the expression of GAS5, miR-27a and BNIP3. We found that high glucose stimulation suppressed HK-2 cell viability but induced cell apoptosis. The expression of GAS5 was increased in HK-2 cells under high glucose environment. Silence of GAS5 mitigated the high glucose-caused HK-2 cell viability reduction and apoptosis. Overexpression of miR-27a reversed the effects of GAS5 on high glucose-stimulated HK-2 cells. Overexpression of BNIP3 aggravated the high glucose-caused HK-2 cell viability reduction, apoptosis and activation of JNK pathway. Knockdown of BNIP3 had opposite effects. In conclusion, this research further confirmed the pro-apoptotic roles of GAS5 in renal tubular epithelial cells under high glucose environment. Silence of GAS5 alleviated high glucose toxicity to human renal tubular epithelial HK-2 cells might be via down-regulating miR-27a and BNIP3, and then inactivating JNK pathway. Highlights HG suppresses HK-2 cell viability, but promotes cell apoptosis; HG enhances the expression of GAS5 in HK-2 cells; Silence of GAS5 alleviates the HG-caused HK-2 cell toxicity; miR-27a participates in the effects of GAS5 silencing on HG-stimulated HK-2 cells; BNIP3 is regulated by miR-27a and related to the HG toxicity to HK-2 cells.

Long noncoding RNA GAS5 inhibits cell proliferation and fibrosis in diabetic nephropathy by sponging miR-221 and modulating SIRT1 expression

Diabetic nephropathy (DN) is one of the leading causes of end-stage renal diseases worldwide. This study is designed to investigate the underlying function and mechanism of a novel lncRNA GAS5 in the progression of DN. We found that lncRNA GAS5 expression level was decreased in type 2 diabetes (T2D) with DN compared with that in patients without DN. Moreover, lncRNA GAS5 expression level was negatively associated with the severity of DN-related complications. lncRNA GAS5 inhibited MCs proliferation and caused G0/1 phase arrest. lncRNA GAS5 overexpression alleviated the expression of fibrosis-related protein in mesangial cells (MCs). The dual-luciferase reporter assay and RNA binding protein immunoprecipitation (RIP) assay results revealed that lncRNA GAS5 functions as an endogenous sponge for miR-221 via both the directly targeting way and Ago2-dependent manner. Furthermore, SIRT1 was confirmed as a target gene of miR-221. lncRNA GAS5 upregulated SIRT1 expression and inhibited MCs proliferation and fibrosis by acting as an miR-221 sponge. Finally, we found that lncRNA GSA5 suppressed the development of DN in vivo. Thus, lncRNA GAS5 was involved in the progression of DN by sponging miR-221 and contributed to lncRNA-directed diagnostics and therapeutics in DN.

Long non-coding RNA GAS5 inhibits DDP-resistance and tumor progression of epithelial ovarian cancer via GAS5-E2F4-PARP1-MAPK axis

Background

Epithelial ovarian cancer (EOC) is the malignant tumor of the female reproductive system with the highest fatality rate. Tolerance of chemotherapeutic drugs like cisplatin (DDP) occurring in very early stage is one of the important factors of the poor prognosis of epithelial ovarian cancer. Here we aim to study the dysregulation of a particular long noncoding RNA, lncRNA GAS5, and its role in EOC progression.

Methods

The low expression of lncRNA GAS5 in EOC tissues and OC cell lines was determined by microarray analyses and Real-Time qPCR. Flow cytometer assays were used to detect cell cycle and apoptosis of OC cells. CCK8 assay were performed to investigate the DDP sensitivity of OC cells. Western blot was carried out to detect cell growth markers, apoptotic markers, PARP1, E2F4, MAPK pathway protein expression and other protein expression in OC cell lines. The binding of GAS5 and E2F4 were proved by RNA pull-down and RIP assay. The effect of E2F4 on PARP1 were determined by CHIP-qPCR assay and luciferase reporter assay. The effect of lncRNA GAS5 on OC cells was assessed in vitro and in vivo.

Results

By microarray (3 EOC tissues νs. 3 normal ovary tissues) and RT- qPCR (53 EOC tissues νs. 10 normal ovary tissues) we identified lncRNA GAS5 to be dramatically low expressed in EOC samples and correlated with prognosis. Compared with sensitive cell lines, GAS5 was also low expressed in DDP resistant OC cell lines, and over-expression of GAS5 significantly enhanced the sensitivity of OC cells to DDP in vivo and in vitro. Meanwhile the over-expression of GAS5 also caused OC cells G0/G1 arrest and apoptosis increase. Mechanistically, GAS5 might regulate PARP1 expression by recruiting the transcription factor E2F4 to its promoter, and then affect the MAPK pathway activity. Due to the 5’TOP structure, GAS5 could be regulated by transcription inhibitor rapamycin in OC cells.

Conclusion

Here we explored the specific mechanisms of EOC cisplatin resistance and tumor progress due to lncRNA-GAS5, presented the GAS5-E2F4-PARP1-MAPK axis and its role in OC drug-sensitivity and progression for the first time, and the results may provide experimental basis for clinical application.

Long noncoding RNA GAS5 silencing inhibits the expression of KCNQ3 by sponging miR-135a-5p to prevent the progression of epilepsy

Epilepsy is one of the most common neurological disorders in humans. Recently, long noncoding RNAs (lncRNAs) have been reported to be important players in neurological diseases. Herein, this study aimed to examine the effect of lncRNA GAS5 on the occurrence of epilepsy in rat and cell models of epileptic seizure. The expression of lncRNA GAS5 was measured in the established rat and cell models. The binding sites between lncRNA GAS5 and miR-135a-5p, as well as those between miR-135a-5p and 3' untranslated region of KCNQ3 were predicted by miRDB and Targetscan, separately, followed by verification using dual-luciferase reporter gene assay. The expression of miR-135a-5p was measured in response to the overexpression of lncRNA GAS5. The mRNA and protein levels of KCNQ3 were examined in response to overexpression of miR-135a-5p. Next, the latency of epilepsy and frequency of epileptic seizures were assessed in rats injected with Lv-shGAS5 and Lv-miR-135a-5p in epileptic seizure model. In the rat and cell models, lncRNA GAS5 was highly expressed when epileptic seizure was induced. The expression of miR-135a-5p was decreased by overexpression of lncRNA GAS5. Meanwhile, the mRNA and protein levels of KCNQ3 were decreased in response to knockdown of miR-135a-5p. After the treatment of Lv-shGAS5 and Lv-miR-135a-5p, the average latent period of epilepsy was prolonged and the frequency of seizures was decreased. The key findings of the present study provide evidence emphasizing that lncRNA GAS5 functions as a competitive endogenous RNA of miR-135a-5p to increase expression of KCNQ3, and lncRNA GAS5 silencing inhibited the occurrence and progression of epilepsy.

LncRNA GAS5 overexpression downregulates IL-18 and induces the apoptosis of fibroblast-like synoviocytes

BACKGROUND

Long non-coding RNA (lncRNA) growth arrest specific transcript 5 (GAS5) negatively regulates interleukin-18 (IL-18) in ovarian cancer, while IL-18 contributes to the development of rheumatoid arthritis (RA). Therefore, GAS5 may also participate in RA.

METHODS

GAS5 and IL-18 in plasma of RA patients (n = 60) and healthy controls (n = 60) were measured by RT-qPCR and ELISA, respectively. Linear regression was performed to analyze the correlations between plasma levels of IL-18 and GAS5 in both RA patients and healthy controls.

RESULTS

In the present study, we found that plasma GAS5 was downregulated, while IL-18 was upregulated in RA patients than in healthy controls. A significant and inverse correlation between GAS5 and IL-18 was found in RA patients but not in healthy controls. IL-18 treatment did not significantly alter the expression of GAS5 in fibroblast-like synoviocytes, while GAS5 overexpression led to the inhibited expression of IL-18. GAS5 overexpression also resulted in the promoted apoptosis of fibroblast-like synoviocytes.

CONCLUSIONS

Therefore, GAS5 overexpression may improve RA by downregulating IL-18 and inducing the apoptosis of fibroblast-like synoviocytes. Key points • The present study mainly showed that overexpression of GAS5 may assist the treatment of RA. • The mechanism of GAS5 for the treatment of RA involves the downregulating inflammatory IL-18 and mediating the apoptosis of fibroblast-like synoviocytes. • GAS5 and IL-8 were correlated in RA patients but not in healthy controls.

Downregulated Long Noncoding RNA GAS5 Fails to Function as Decoy of CEBPB, Resulting in Increased GDF15 Expression and Rapid Ovarian Cancer Cell Proliferation

Introduction: Growth differentiation factor 15 (GDF15), a newly identified member of transforming growth factor (GDF) superfamily, is upregulated in ovarian (OV) cancer. Upregulated GDF15 positively correlates with poor prognosis of OV cancer. Thus, elucidation of the mechanism underlying GDF15 overexpression is important. Method and Results: PROMO and JASPAR prediction software were used to find transcription factors for GDF15 expression. Data from TCGA database were analyzed to find long noncoding RNAs (lncRNAs) that were also abnormally expressed in OV cancer and had associations with GDF15 expression. Transcription factor CEBPB was predicted as an important regulator of GDF15, confirmed by luciferase reporter assay. However, CEBPB expression was not significantly changed in OV cancer. Data from TCGA database showed that lncRNA GAS5 is downregulated in OV cancer and its expression is negatively correlated with GDF15 expression. RPISeq showed high affinity of GAS5 to CEBPB and this was confirmed by RNA-binding protein immunoprecipitation assay. GAS5 overexpression increased its binding to CEBPB and consequently downregulated GDF15. GAS5 overexpression and GDF15 knockdown decreased viability and increased apoptosis of OV cancer cells, but CEBPB overexpression had opposite effects. However, simultaneous GAS5 and CEBPB overexpression or CEBPB overexpression together with GDF15 knockdown had no effect on cell viability and apoptosis. Conclusion: GAS5 functions as decoy of CEBPB, blocking transcription-promoting effect of CEBPB on GDF15.

Silence of LncRNA GAS5 Protects Cardiomyocytes H9c2 against Hypoxic Injury via Sponging miR-142-5p

The regulatory role of long noncoding RNA (lncRNA) growth arrest-specific transcript 5 (GAS5) in both cancerous and noncancerous cells have been widely reported. This study aimed to evaluate the role of lncRNA GAS5 in heart failure caused by myocardial infarction. We reported that silence of lncRNA GAS5 attenuated hypoxia-triggered cell death, as cell viability was increased and apoptosis rate was decreased. This phenomenon was coupled with the down-regulated expression of p53, Bax and cleaved caspase-3, as well as the up-regulated expression of CyclinD1, CDK4 and Bcl-2. At the meantime, the expression of four heart failure-related miRNAs was altered when lncRNA GAS5 was silenced (miR-21 and miR-142-5p were up-regulated; miR-30b and miR-93 were down-regulated). RNA immunoprecipitation assay results showed that lncRNA GAS5 worked as a molecular sponge for miR-142-5p. More interestingly, the protective actions of lncRNA GAS5 silence on hypoxia-stimulated cells were attenuated by miR-142-5p suppression. Besides, TP53INP1 was a target gene for miR-142-5p. Silence of lncRNA GAS5 promoted the activation of PI3K/AKT and MEK/ERK signaling pathways in a miR-142-5p-dependent manner. Collectively, this study demonstrated that silence of lncRNA GAS5 protected H9c2 cells against hypoxia-induced injury possibly via sponging miR-142-5p, functionally releasing TP53INP1 mRNA transcripts that are normally targeted by miR-142-5p.

lncRNA GAS5/miR-223/NAMPT axis modulates the cell proliferation and senescence of endothelial progenitor cells through PI3K/AKT signaling

Endothelial progenitor cells (EPCs) have been reported to replace the damaged endothelial cells to repair the injured or dead endothelium. However, EPC senescence might lead to the failure in EPC function. Thus, developing an in-depth understanding of the mechanism of EPC senescence might provide novel strategies for related vascular disorders' treatments. Herein, nicotinamide phosphoribosyltransferase (NAMPT) overexpression could increase cell proliferation and suppress cell senescence in EPCs. miR-223 directly bound to the 3'-untranslated region of NAMPT to inhibit its expression, therefore modulating EPC proliferation and senescence through NAMPT and phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling. Long noncoding RNA (lncRNA) GAS5 sponges miR-223, consequently downregulating miR-223 expression. GAS5 knockdown inhibited EPC proliferation and promoted senescence. GAS5 might serve as a competing endogenous RNA for miR-223 to counteract miR-223-mediated suppression on NAMPT, thus regulating EPC proliferation and senescence via the PI3K/AKT signaling pathway. In summary, our findings provide a solid experimental basis for understanding the role and mechanism of lncRNA GAS5/miR-223/NAMPT axis in EPC proliferation and senescence.

lncRNA GAS5 restrains CCl4-induced hepatic fibrosis by targeting miR-23a through the PTEN/PI3K/Akt signaling pathway

Hepatic fibrosis is chronic liver damage with many causes that has a relatively high death rate. The current study showed that long noncoding RNA (lncRNA) growth arrest-specific transcript 5 (GAS5), microRNA-23a (miR-23a), and phosphatase and tensin homolog (PTEN) play important roles in the pathological process of hepatic fibrosis but have a relatively unclear regulatory mechanism. This study aimed to investigate the roles of lncRNA GAS5, miR-23a, and PTEN in the pathological process of hepatic fibrosis and hepatic stellate cell (HSC) activation. We used carbon tetrachloride (CCl₄) intraperitoneal injections to establish a rat hepatic fibrosis model and exogenous transforming growth factor-β1 to establish an HSC activation model. Quantitative RT-PCR, Western blot, dual-luciferase reporter system, and RNA pull-down assays were used to investigate which microRNAs and lncRNAs participate in the process of hepatic fibrosis and HSC activation. miR-23a expression increased significantly in hepatic fibrosis tissues and activated HSCs. miR-23a interaction with and degradation of PTEN further influenced the downstream signaling pathway phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin/Snail (PI3K/Akt/mTOR/Snail), causing E-cadherin expression levels to decrease and α-smooth muscle actin and collagen I expression levels to increase. lncRNA GAS5 can be used as a sponge platform for miR-23a to decrease miR-23a expression levels competitively. We revealed the role of the lncRNA GAS5/miR-23a/PTEN/PI3K/Akt/mTOR/Snail signaling pathway in hepatic fibrosis, providing molecular targets for the treatment of hepatic fibrosis. NEW & NOTEWORTHY This is the first study revealing that microRNA-23a (miR-23a) promotes hepatic fibrosis through the phosphatase and tensin homolog/phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin/Snail signaling pathway, and long noncoding RNA (lncRNA) growth arrest-specific transcript 5 (GAS5) can act as a sponge platform for miR-23a. Therefore, lncRNA GAS5/miR-23a may bring molecular targets for hepatic fibrosis therapy.

Stabilization of lncRNA GAS5 by a Small Molecule and Its Implications in Diabetic Adipocytes

Long noncoding RNA (lncRNA) are regulatory RNAs >200 nt. We previously showed that lncRNA GAS5 decreases significantly in serum of type 2 diabetes mellitus (T2DM) patients. Hence, we sought to decipher the molecular mechanisms underlying the role of GAS5 in T2DM in adipose tissue. Using CHIP-RIP, we demonstrate that GAS5 binds to promoter of insulin receptor to regulate its expression, and its depletion inhibits glucose uptake and insulin signaling. Toward stabilizing GAS5 levels in T2DM, we incorporated a strategy to limit the degradation of GAS5 by blocking the interaction of GAS5 and UPF1 with a small molecule identified using OBTC screening strategy. NP-C86 binds to GAS5 with high affinity, and increases GAS5 levels and glucose uptake in diabetic patient adipocytes. As a broader impact, NP-C86 may be used as a molecular probe to investigate the intricacies of GAS5 in relevant biological systems as it offers specificity, efficient cellular uptake and is non-cytotoxic.

lncRNA GAS5 promotes M1 macrophage polarization via miR-455-5p/SOCS3 pathway in childhood pneumonia

OBJECTIVES

We herein aimed to explore whether growth arrest-specific 5 (GAS5) promotes M1 macrophage polarization in childhood pneumonia and to investigate the underlying mechanism.

METHODS

Relative GAS5 and miR-455-5p expression and suppressor of cytokine signaling 3 (SOCS3) messenger RNA level were examined using quantitative reverse transcription polymerase chain reaction. Protein expression of SOCS3 and the Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathway-related proteins was detected using western blot analysis. Luciferase activity assay was performed to test whether miR-455-5p could bind to GAS5 or SOCS3. The macrophage phenotype was determined using flow cytometry analysis and enzyme-linked immunosorbent assay.

RESULTS

The macrophage polarization toward the M2 phenotype was observed in peripheral blood from pneumonia children. Furthermore, GAS5 and SOCS3 expression were upregulated but miR-455-5p downregulated in human monocyte-derived macrophages from pneumonia children compared with the control group. Furthermore, GAS5 acted as a sponge for miR-455-5p to facilitate SOCS3 expression. Moreover, miR-455-5p mimic and SOCS3 knockdown significantly reversed the GAS5 overexpression-mediated suppression of the JAK2/STAT3 signaling and promotion of M1 polarization.

CONCLUSION

GAS5 promotes M1 macrophage polarization by acting as a competing endogenous RNA of miR-455-5p to facilitate SOCS3 expression in childhood pneumonia.

lncRNA GAS5 Reverses EMT and Tumor Stem Cell-Mediated Gemcitabine Resistance and Metastasis by Targeting miR-221/SOCS3 in Pancreatic Cancer

Dysregulated long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) mediating chemotherapeutic drug effects and metastasis in pancreatic cancer (PC) are key reasons for the poor prognosis of this disease. lncRNA growth arrest-specific 5 (GAS5) is reported to be a tumor suppressor in multiple cancers. However, the functions of GAS5 and its related miRNAs in PC are poorly understood. This study explored the potential functions and mechanisms of GAS5 in PC gemcitabine resistance and metastasis. The results show that overexpression of GAS5 suppressed the proliferation, migration, gemcitabine resistance, stem cell-like properties, and epithelial-mesenchymal transition (EMT) of PC cells by directly binding to and suppressing miR-221 expression and enhancing suppressor of cytokine signaling 3 (SOCS3) expression. The effects of miR-221 overexpression on proliferation, migration, gemcitabine resistance, stem cell-like properties, and EMT inhibition were reversed by SOCS3 overexpression in PC cells. Additionally, GAS5 promoted gemcitabine-induced tumor growth and metastasis inhibition, as determined by Ki-67 staining and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), bioluminescence imaging, and the detection of cell-like properties and EMT in vivo. Thus, lncRNA GAS5 functioned as a competing endogenous RNA for miR-221, and it suppressed cell growth, metastasis, and gemcitabine resistance in PC by regulating the miR-221/SOCS3 pathway mediating EMT and tumor stem cell self-renewal.

Sialidase Deficiency in Porphyromonas gingivalis Increases IL-12 Secretion in Stimulated Macrophages Through Regulation of CR3, IncRNA GAS5 and miR-21

Porphyromonas gingivalis (P. gingivalis) is a major periodontal pathogen that can induce an immune response leading to a destructive inflammatory process. During the inflammatory process, interleukin-12 (IL-12) is secreted, correlating with bacterial clearance by macrophages. Bacterial sialidase has recently been shown to influence the synthesis and modification of the macromolecules on its surface, and is associated with the interaction between bacteria and host cells. We have previously constructed a P. gingivalis sialidase gene mutant strain in P. gingivalis W83 (ΔPG0352) and found that ΔPG0352 showed less pathogenicity than the wild-type strain. In this study, U937-differentiated macrophages were stimulated by P. gingivalis W83, ΔPG0352, or PG0352 complemented strain (comΔPG0352). Transmission electron microscopy showed that P. gingivalis caused a loss of membrane integrity in macrophages and the intracellular bacteria were enclosed within endocytic vacuoles. The expression of both IL-12p35 and IL-12p40 genes and the levels of IL-12p70 were significantly higher in U937 stimulated by ΔPG0352 than in those with P. gingivalis W83 and comΔPG0352. In order to explain why ΔPG0352 induced more IL-12 in macrophages, immunofluorescence assays, PCR arrays, and gene silence or overexpression experiments were carried out. Immunofluorescence assays showed that ΔPG0352 induced lower expression of CR3 in macrophages. After CR3 was suppressed, there were no significant differences in the IL-12p70 levels between macrophages stimulated by P. gingivalis W83, ΔPG0352 or comΔPG0352. PCR array experiments showed that miR-21 and lncRNA GAS5 were differentially expressed between macrophages stimulated by P. gingivalis W83 and ΔPG0352, which had been identified by real-time PCR. The results of CR3 blocking and lncRNA GAS5 gene silence or overexpression showed that the difference in IL-12 levels between P. gingivalis W83 and ΔPG0352 groups was associated with CR3, lncRNA GAS5 and miR-21. Thus it can be concluded that the sialidase-deficient strain is more easily cleared by attenuating CR3 activation, reducing the inhibition of lncRNA GAS5, inducing less miR-21 and more IL-12 in macrophages. These results indicate that inhibiting the activity of sialidase in P. gingivalis will cause rapid clearing by macrophages.

Corylin Suppresses Hepatocellular Carcinoma Progression via the Inhibition of Epithelial-Mesenchymal Transition, Mediated by Long Noncoding RNA GAS5

Corylin is a flavonoid extracted from the nuts of Psoralea corylifolia L. (Fabaceae), which is a widely used anti-inflammatory and anticancer herb in China. Recent studies revealed antioxidant, anti-inflammatory, and bone differentiation–promoting effects of corylin. However, there are no studies examining the anticancer activity of corylin. In this study, we used cells and animal models to examine the antitumor effects of corylin on hepatocellular carcinoma (HCC) and then studied its downstream regulatory mechanisms. The results showed that corylin significantly inhibited the proliferation, migration, and invasiveness of HCC cells and suppressed epithelial–mesenchymal transition. We found that the anti-HCC mechanism of corylin’s action lies in the upregulation of tumor suppressor long noncoding RNA growth arrest-specific transcript 5 (GAS5) and the activation of its downstream anticancer pathways. In animal experiments, we also found that corylin can significantly inhibit tumor growth without significant physiological toxicity. The above results suggest that corylin has anti-HCC effects and good potential as a clinical treatment.

Downregulation of LncRNA GAS5 causes trastuzumab resistance in breast cancer

Therapeutic resistance to trastuzumab caused by dysregulation of long noncoding RNAs (lncRNAs) is a major obstacle to clinical management of HER2-positive breast cancer. To investigate which lncRNAs contribute to trastuzumab resistance, we screened a microarray of lncRNAs involved in the malignant phenotype of trastuzumab-resistant SKBR-3/Tr cells. Expression of the lncRNA GAS5 was decreased in SKBR-3/Tr cells and in breast cancer tissue from trastuzumab-treated patients. Inhibition of GAS5 promoted SKBR-3 cell proliferation, and GAS5 knockdown partially reversed lapatinib-induced inhibition of SKBR-3/Tr cell proliferation. GAS5 suppresses cancer proliferation by acting as a molecular sponge for miR-21, leading to the de-repression of phosphatase and tensin homologs (PTEN), the endogenous target of miR-21. Moreover, mTOR activation associated with reduced GAS5 expression was required to suppress PTEN. This work identifies GAS5 as a novel prognostic marker and candidate drug target for HER2-positive breast cancer.

Long noncoding RNA GAS5 suppresses the migration and invasion of hepatocellular carcinoma cells via miR-21

Long noncoding RNAs (lncRNAs) are aberrantly expressed in various cancers. Although lncRNA GAS5 (growth arrest-specific transcript 5) has been characterized as a tumor suppressor in some kinds of cancer, its role and function in hepatocellular carcinoma (HCC) remain unknown. The present report demonstrates that there are lower levels of GAS5, PDCD4, and PTEN and higher levels of microRNA-21 (miR-21) in HCC tissues than in adjacent normal tissues. Moreover, the levels of GAS5 and miR-21 were correlated with the clinicopathological characteristics of HCC. HCC patients with higher levels of GAS5 or with the lower levels of miR-21 have longer survival times. There are lower levels of GAS5 and higher levels of miR-21 in HCC cell lines (Be7402, SMMC-7721, and HCCLM3) than in normal liver L-02 cells, and the levels correlate with the aggression of the HCC cell lines. Knockdown of GAS5 upregulates miR-21 levels in Bel-7402 cells (weakly aggressive); in contrast, there are opposite changes in HCCLM3 cells (highly aggressive). Moreover, GAS5 that upregulated or downregulated the expression of PDCD4 and PTEN was reversed by inhibiting or overexpressing miR-21 level in Bel-7402 and HCCLM3 cells. Then, overexpression of GAS5 suppresses the migration and invasion of HCC cells and high expression of miR-21 largely eliminates GAS5-mediated suppression of HCC cell migration and invasion. Thus, GAS5 acts as a tumor suppressor in HCCs through negative regulation of miR-21 and its targets and proteins about migration and invasion in cancer cells, which may be a target for treating HCC.