LncRNA PCAT29 suppresses cell proliferation, invasion, and migration in renal carcinoma by regulating FLOT1

Secretory products from epicardial adipose tissue induce adverse myocardial remodeling after myocardial infarction by promoting reactive oxygen species accumulation

Adverse myocardial remodeling, manifesting pathologically as myocardial hypertrophy and fibrosis, often follows myocardial infarction (MI) and results in cardiac dysfunction. In this study, an obvious epicardial adipose tissue (EAT) was observed in the rat model of MI and the EAT weights were positively correlated with cardiomyocyte size and myocardial fibrosis areas in the MI 2- and 4-week groups. Then, rat cardiomyocyte cell line H9C2 and primary rat cardiac fibroblasts were cultured in conditioned media generated from EAT of rats in the MI 4-week group (EAT-CM). Functionally, EAT-CM enlarged the cell surface area of H9C2 cells and reinforced cardiac fibroblast activation into myofibroblasts by elevating intracellular reactive oxygen species (ROS) levels. Mechanistically, miR-134-5p was upregulated by EAT-CM in both H9C2 cells and primary rat cardiac fibroblasts. miR-134-5p knockdown promoted histone H3K14 acetylation of manganese superoxide dismutase and catalase by upregulating lysine acetyltransferase 7 expression, thereby decreasing ROS level. An in vivo study showed that miR-134-5p knockdown limited adverse myocardial remodeling in the rat model of MI, manifesting as alleviation of cardiomyocyte hypertrophy and fibrosis. In general, our study clarified a new pathological mechanism involving an EAT/miRNA axis that explains the adverse myocardial remodeling occurring after MI.

LINC00476 Suppresses the Progression of Non-Small Cell Lung Cancer by Inducing the Ubiquitination of SETDB1

Long non-coding RNAs are involved in the tumorigenesis of non-small cell lung cancer (NSCLC). Here we investigated whether LINC00476 affects the proliferation, invasion and migration of NSCLC cells via the SETDB1-activated Wnt/β-catenin pathway. The expression of LINC00476, SETDB1, Wnt1 and β-catenin were determined in NSCLC tumor tissues and the paired adjacent tissues, as well as in NSCLC cell lines and bronchial epithelioid cell lines. Cell proliferation, invasion and migration were determined using cell counting kit-8 assay and transwell assay. The relationship between LINC00476 and SETDB1 was elucidated using RNA pull-down, RNA immunoprecipitation and ubiquitination assays. LINC00476 was found to be significantly downregulated, while SETDB1, Wnt1 and β-catenin were upregulated in NSCLC tumor tissues and cell lines compared to the normal ones. Overexpression of LINC00476 promoted the proliferation, invasion and migration of NSCLC cells, and suppressed tumor growth in the mouse xenograft. Meanwhile, overexpression of LINC00476 induced the degradation of SETDB1 by promoting its ubiquitination. The simultaneous overexpression of LINC00476 and SETDB1 negated the inhibition of LINC00476 overexpression on the proliferation, invasion and migration of NSCLC cells. In conclusion, these findings indicate that LINC00476 acts as a tumor suppressor in NSCLC by downregulating SETDB1, which provides a novel target in the treatment of NSCLC.

Downregulated long non-coding RNA LINC01093 in liver fibrosis promotes hepatocyte apoptosis via increasing ubiquitination of SIRT1

The apoptosis of hepatocytes contributes to the activation of hepatic stellate cells (HSCs), thus promoting the accumulation of extracellular matrix proteins and aggravating liver fibrosis. Silent information regulator 1 (SIRT1) is an anti-fibrotic protein whose downregulation induces hepatocyte apoptosis. This study aims to identify whether SIRT1 is regulated by long non-coding RNA LINC01093 and explore its underlying mechanisms. Liver fibrosis was induced in mice using CCl4, and the differential expressions of several fibrosis-related long noncoding RNAs were detected in liver tissues. The effect of LINC01093 on cell apoptosis and viability of hepatocytes were investigated after LINC01093 overexpression or knockdown using flow cytometry and MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. The anti-fibrotic effect of LINC01093 overexpression was observed in vivo. LncRNA LINC01093 is downregulated in CCl4-induced liver tissues and TGF-β1-stimulated hepatocytes. Downregulated LINC01093 promoted cell apoptosis and inhibited cell viability of hepatocytes. The co-culture between LINC01093-knockdown hepatocytes and HSCs increased the expressions of pro-fibrotic proteins. Downregulated LINC01093 promoted hepatocyte apoptosis via promoting degradation and ubiquitination of SIRT1 under TGF-β1 stimulation. The injection of LINC01093-overexpressing vectors alleviated liver fibrosis in vivo. In liver fibrosis, the downregulated LINC01093 promoted hepatocyte apoptosis, which is mediated by increasing the degradation and ubiquitination of SIRT1.

Hypermethylation-mediated downregulation of long non-coding RNA MEG3 inhibits osteogenic differentiation of bone marrow mesenchymal stem cells and promotes pediatric aplastic anemia

BACKGROUND

The reduced osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) is the typical characteristics of pediatric aplastic anemia (AA) pathogenesis. Long non-coding RNA MEG3 is reported to promote osteogenic differentiation of BMSCs via inducing BMP4 expression.

OBJECTIVE

This study aims to investigate the mechanism of DNMT1/MEG3/BMP4 pathway in osteogenic differentiation of BMSCs in pediatric AA.

METHODS

BMSCs were isolated and purified from bone marrows of pediatric AA patients (n = 5) and non-AA patients (n = 5). The expression of DNMT1, MEG3, and BMP4 in isolated BMSCs was detected using quantitative real-time PCR and western blot analysis. Osteogenic differentiation was determined using Alizarin red staining. The methylation of MEG3 promoter and the interaction between DNMT1 and MEG3 promoter were detected using methylation-specific PCR and chromatin immunoprecipitation assay, respectively.

RESULTS

Lowly expressed MEG3 and BMP4 and highly expressed DNMT1 were observed in BMSCs of pediatric AA patients. The overexpression of MEG3 promoted osteogenic differentiation of BMSCs. Luciferase reporter assay showed that MEG3 overexpression increased transcriptional activity of BMP4. The inhibitor of methylation, 5-azacytidine, suppressed DNMT1 expression and reduced methylation of MEG3 promoter. Overexpression of DNMT1 increased the binding between DNMT1 and MEG3 promoter. The simultaneous overexpression of DNMT1 and MEG3 restored the inhibition of osteogenic differentiation caused by DNMT1 overexpression alone.

CONCLUSIONS

Our findings indicated that DNMT1 mediated the hypermethylation of MEG3 promoter in BMSCs, and DNMT1/MEG3/BMP4 pathway modulated osteogenic differentiation of BMSCs in pediatric AA.

Hypermethylation-mediated downregulation of lncRNA PVT1 promotes granulosa cell apoptosis in premature ovarian insufficiency via interacting with Foxo3a

Long noncoding RNA PVT1 is involved in the progression of female gynecological cancers. However, the role of PVT1 in ovarian granulosa cell apoptosis-mediated premature ovarian insufficiency (POI) remains unclear. This study aims to elucidate the role of PVT1 in ovarian granulosa cell apoptosis-mediated POI. The expression of PVT1 was compared between ovarian tissues from POI patients and normal controls. The methylation level in the PVT1 promoter region was detected by methylation-specific polymerase chain reaction. The interaction between PVT1 and forkhead box class O3A (Foxo3a) was confirmed by RNA pull-down and RNA immunoprecipitation assays. Granulosa cell apoptosis was detected using flow cytometry. The effect of PVT1 on transcription activity of Foxo3a was detected by luciferase reporter assay. The expression of PVT1 was low in the POI ovarian tissues compared with the controls, and such a low expression was related to the hypermethylation of the PVT1 promoter. PVT1 was localized in both the cytoplasm and the nucleus of granulosa cells. We determined that PVT1 could bind with Foxo3a and that downregulating PVT1 by small interfering RNAs inhibited Foxo3a phosphorylation by promoting SCP4-mediated Foxo3a dephosphorylation, resulting in an increase in Foxo3a transcription activity. Moreover, downregulating PVT1 promoted granulosa cell apoptosis by increasing the Foxo3a protein levels. An in vivo experiment showed that the injection of PVT1 overexpressing vectors restored the ovarian function in POI mice. Hypermethylation-induced downregulation of PVT1 promotes granulosa cell apoptosis in POI by inhibiting Foxo3a phosphorylation and increases the Foxo3a transcription activity.

Long Noncoding RNA NEAT1 Suppresses Proliferation and Promotes Apoptosis of Glioma Cells Via Downregulating MiR-92b

BACKGROUND

The mechanisms underlying the proliferation and apoptosis of glioma cells remain unelucidated. A recent study has revealed that microRNA-92b (miR-92b) inhibits apoptosis of glioma cells via downregulating DKK3. Notably, long noncoding RNA nuclear-enriched abundant transcript 1 (NEAT1) is predicted to have a possible interaction with miR-92b.

OBJECTIVE

This study aimed to identify whether NEAT1 affects glioma cell proliferation and apoptosis via regulating miR-92b.

METHODS

The expression of NEAT1 was compared between glioma tissues and adjacent tissues as well as between glioma cells and normal astrocytes using quantitative real-time polymerase chain reaction. Glioma cell proliferation was determined by using the 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and glioma cell apoptosis was determined by using the flow cytometry.

RESULTS

The expression of NEAT1 was low in glioma tissues and cells compared to the normal ones. Overexpression of NEAT1 inhibited proliferation and promoted apoptosis of glioma cell lines (U-87 MG and U251). The interaction between NEAT1 and miR-92b was confirmed using RNA immunoprecipitation, RNA pull-down assay, and luciferase reporter assay. Importantly, the tumor suppressor function of overexpressing NEAT1 was achieved by downregulating miR-92b and subsequently upregulating DKK3.

CONCLUSION

Our findings indicated that NEAT1 acts as a tumor suppressor in glioma cells, which provides a novel target in overcoming glioma growth.

Linc00514 promotes breast cancer metastasis and M2 polarization of tumor-associated macrophages via Jagged1-mediated notch signaling pathway

BACKGROUND

Tumor-associated macrophages (TAMs) and tumor cells are important components of the tumor microenvironment. M2 polarization of TAMs, which is a major actor in breast cancer malignancy and metastasis, can be induced by breast cancer cells. However, the potential mechanisms of the interaction between breast cancer cells and TAMs remain unclear.

METHODS

The candidate breast cancer-associated long non-coding RNAs (lncRNAs) were analyzed using the GEO database. Functional assays, including MTT assay, Transwell assay, and EdU labeling detection, were performed to investigate the oncogenic role of linc00514 in breast cancer progression. The co-culture and ELISA assays were used to assess the role of linc00514 in macrophage recruitment and M2 polarization. RNA immunoprecipitation, RNA pull-down, and luciferase reporter assays were applied to determine the mechanism of linc00514 in breast cancer metastasis. Mouse xenograft models, mouse pulmonary metastatic models, and mouse primary tumor models were used to assess the role of linc00514 in M2 macrophage polarization and breast cancer tumorigenicity.

RESULTS

Linc00514 was highly expressed in clinical breast cancer tissues and breast cancer cell lines. Overexpression of linc00514 promoted the proliferation and invasion of breast cancer cells and increased xenograft tumor volumes and pulmonary metastatic nodules. Overexpression of linc00514 also increased the percentage of macrophages expressing M2 markers CD206 and CD163. Mechanistically, linc00514 promoted Jagged1 expression in a transcriptional manner by increasing the phosphorylation of a transcription factor STAT3. Subsequently, Jagged1-mediated Notch signaling pathway promoted IL-4 and IL-6 secretions in breast cancer cells and ultimately inducing M2 polarization of macrophages.

CONCLUSION

Linc00514 plays an important role in regulating breast cancer tumorigenicity and M2 macrophage polarization via Jagged1-mediated Notch signaling pathway.

WITHDRAWN: GAS5 enhances natural killer cell-mediated killing by promoting ubiquitination of SESN2 in prostate cancer cells

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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.