Search

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. In this study, we planned to investigate the role of GAS5 in GC metastasis. 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. 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. 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. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To observe the effect of long non-coding ribonucleic acid (lncRNA) growth arrest specific 5 (GAS5) knockdown on the apoptosis of neurons in rats with cerebral infarction (CI), and to explore the potential mechanism of lncRNA GAS5 in the pathogenesis of CI. MATERIALS AND METHODS: A total of 60 adult male Sprague Dawley (SD) rats aged 12-14 weeks old and weighing (267.14±6.49) g were randomly divided into three groups: Sham operation group (Sham group, n=20), CI group (n=20) and CI + lncRNA GAS5 knockdown group [CI + GAS5 small interfering RNA (siRNA) group, n=20]. The rat model of focal CI was constructed by carotid artery embolization. After the CI model was successfully induced, a certain amount of lncRNA GAS5 siRNAs was injected into the rat lateral ventricle in a stereotactic manner. At 24 h after operation, triphenyl tetrazolium chloride (TTC) method was used to detect the infarction area in brain tissues of rats in each group. At the same time, the pathological changes of neurons in the hippocampus and prefrontal cortex of rats in each group were observed via hematoxylin and eosin (H&E) staining. The expressions of B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (BAX) were detected via Western blotting. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was adopted to detect the number of apoptotic neurons in brain tissues of rats in each group. Meanwhile, the expression level of Notch intracellular domain (NICD) proteins was measured using the Western blotting technique and immunohistochemical staining. RESULTS: Reverse transcription-polymerase chain reaction (RT-PCR) showed that the lncRNA GAS5 expression in brain tissues of rats in CI group was significantly higher than that of rats in Sham group (p<0.05). TTC staining results revealed that lncRNA GAS5 knockdown could remarkably reduce the CI area of rats in CI group (p<0.05). In addition, inhibiting lncRNA GAS5 could also significantly reduce the level of pro-apoptotic gene BAX and increase the expression level of anti-apoptotic gene Bcl-2 (p<0.05). In the meantime, the number of apoptotic neurons in CI + GAS5 siRNA group was also evidently decreased (p<0.05). Finally, it was found that lncRNA GAS5 knockdown notably inhibited the expression of NICD proteins (p<0.05). CONCLUSIONS: The inhibitory effect of lncRNA GAS5 knockdown on the apoptosis of neurons in CI rats may be related to the activation of the Notch1 signaling pathway. LncRNA GAS5 may be a new target for clinical treatment of CI. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The aim of this study was to investigate the effect of long non-coding ribonucleic acid (lncRNA) growth arrest specific 5 (GAS5) on acute myocardial infarction (AMI) model rats and to explore its regulatory mechanism. MATERIALS AND METHODS: The rat model of AMI was established by subcutaneous injection of isoproterenol (ISO). 30 Sprague Dawley (SD) rats were randomly divided into three groups, including Control group, Model group, and lncRNA GAS5 inhibitor [small interfering ribonucleic acid (siRNA) GAS5] group. Hematoxylin and eosin (H&E) staining was used to detect the pathological damage of myocardial tissues in rats of each group. Myocardial cell apoptosis in each group determined via terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. The levels of matrix metalloproteinase (MMP)-2 and MMP-9 in the serum of rats in each group were examined by enzyme-linked immunosorbent assay (ELISA). Reverse transcription-polymerase chain reaction (RT-PCR) was adopted to measure the expression level of miR-21 in rat myocardial tissues. RESULTS: Compared with Control group, rats in Model group had significantly poor cardiac function, serious pathological damage of myocardial tissues, as well as increased apoptosis rate of myocardial cells. Meanwhile, the levels of MMP-2 and MMP-9 were significantly elevated in serum of Model group, while miR-21 level was down-regulated. In comparison with Model group, rats in siRNA GAS5 group exhibited significantly improved cardiac function, alleviated pathological damage to myocardial tissues, as well as decreased apoptosis rate of myocardial cells. Furthermore, the levels of MMP-2 and MMP-9 decreased significantly in serum of siRNA GAS5 group, whereas the expression level of miR-21 in myocardial tissues was down-regulated. CONCLUSIONS: SiRNA GAS5 can enhance the cardiac function of AMI model rats, relieve pathological damage, reduce myocardial cell apoptosis, and inhibit the occurrence of myocardial fibrosis. The possible underlying mechanism may be associated with up-regulation of miR-21. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The aim of this study was to elucidate whether long non-coding RNA (lncRNA) GAS5 could target microRNA-498 to regulate RUNX2, thus alleviating the development of osteoporosis. PATIENTS AND METHODS: Human multipotential mesenchymal stem cells (hMSCs) were isolated from bone marrow of osteoporosis patients or healthy controls. Quantitative Real-time polymerase chain reaction (qRT-PCR) was performed to detect the expression levels of GAS5, microRNA-498 and RUNX2 in hMSCs of osteoporosis patients and controls, respectively. Meanwhile, the protein level of RUNX2 in hMSCs was detected by Western blot. Furthermore, alkaline phosphatase (ALP) activity assay and ALP staining were performed to evaluate the degree of osteogenic differentiation under the control of GAS5, microRNA-498 and RUNX2. RESULTS: MicroRNA-498 was highly expressed in hMSCs derived from osteoporosis patients, whereas GAS5 and RUNX2 were lowly expressed. GAS5 overexpression significantly increased ALP activity and promoted osteogenic differentiation of hMSCs derived from osteoporosis patients. Meanwhile, GAS5 significantly promoted osteogenic differentiation by mediating microRNA-498 expression to up-regulate RUNX2. Co-overexpression of GAS5 and microRNA-498 could remarkably reverse the increase of RUNX2 expression. Besides, RUNX2 overexpression markedly elevated ALP activity. CONCLUSIONS: LncRNA GAS5 is lowly expressed in patients with osteoporosis. Overexpression of GAS5 promotes osteogenic differentiation of hMSCs through regulating microRNA-498 to up-regulate RUNX2 expression, thus alleviating the development of osteoporosis. [ABSTRACT FROM AUTHOR]

Objective: Intracerebral hemorrhage (ICH) is the most devastating stroke subtype. Transcription factor Forkhead box O1 (FoxO1) is extensively implicated in cerebral injury. This study investigated the mechanism of FoxO1 in neurological function recovery in ICH mice.Methods: A murine model of ICH was established. The modified neurological severity score (mNSS), forelimb placement test, and corner turn test were adopted to evaluate the neurological function of mice. The brain water content was measured and the pathological changes of cerebral tissues were observed. The levels of IL-1β, IL-6, and TNF-α were determined. The expressions of FoxO1, lncRNA GAS5, miR-378a-5p, and heat shock 70 kDa protein 5 (Hspa5) in mouse cerebral tissues were examined. The binding relationships among FoxO1, lncRNA GAS5, miR-378a-5p, and Hspa5 were validated. Functional rescue experiments were designed to verify the role of lncRNA GAS5/miR-378a-5p/Hspa5 axis in neurological function recovery in ICH mice.Results: FoxO1 was highly expressed in cerebral tissues of ICH mice. FoxO1 silencing facilitated neurological function recovery in ICH mice, evidenced by decreased mNSS, improved forelimb placement rate, reduced turning defects, declined brain water content, relieved edema, intracellular vacuoles, and inflammatory cell infiltration, and reduced IL-1β, IL-6, and TNF-α levels. FoxO1 enhanced lncRNA GAS5 expression by binding to its promoter. LncRNA GAS5 facilitated Hspa5 transcription by sponging miR-378a-5p. Intervention of lncRNA GAS5/miR-378a-5p/Hspa5 axis reversed the promoting effect of FoxO1 silencing on the neurological function recovery in ICH mice.Conclusion: FoxO1 silencing facilitated neurological function recovery in ICH mice via the lncRNA GAS5/miR-378a-5p/Hspa5 axis. [ABSTRACT FROM AUTHOR]