17-701 Sigma-AldrichEZ-Magna RIP™ RNA-Binding Protein Immunoprecipitation Kit

Aberrant Hedgehog signaling and excessive activation of the Gli family of transcriptional activators are key drivers of medulloblastoma (MB), the most common human pediatric brain malignancy. MB originates mainly from cerebellar granule neuron progenitors (CGNP), but the mechanisms underlying CGNP transformation remain largely obscure. In this study, we found that suppression of the noncoding RNA Nkx2-2as promoted Sonic Hedgehog (Shh)-potentiated MB development. Nkx2-2as functioned as a competing endogenous RNA against miR-103 and miR-107, sequestering them and thereby derepressing their tumor suppressive targets BTG2 and LATS1 and impeding cell division and migration. We also found that Nkx2-2as tethered miR-548m and abrogated its LATS2 targeting activity. Shh signaling impaired Nkx2-2as expression by upregulating the transcriptional repressor FoxD1. In clinical specimens of Shh-subgroup MB, we validated coordinated expression of the aforementioned proteins. Notably, exogenous expression of Nkx2-2as suppressed tumorigenesis and prolonged animal survival in MB mouse models. Our findings illuminate the role of noncoding RNAs in Hedgehog signaling and MB occurrence, with implications for identifying candidate therapeutic targets for MB treatment.Significance: These findings illuminate the role of noncoding RNAs in Hedgehog signaling and an interplay between the Hedgehog and Hippo pathways in medulloblastoma pathogenesis. Cancer Res; 78(4); 962-73. ©2017 AACR.

Aberrant chromatin transformation dysregulates gene expression and may be an important driver of tumorigenesis. However, the functional role of chromosomal dynamics in tumorigenesis remains to be elucidated. Here, using in vitro and in vivo experiments, we reveal a novel long noncoding (lncing) driver at chr12p13.3, in which a novel lncRNA GALNT8 Antisense Upstream 1 (GAU1) is initially activated by an open chromatin status, triggering recruitment of the transcription elongation factor TCEA1 at the oncogene GALNT8 promoter and cis-activates the expression of GALNT8. Analysis of The Cancer Genome Atlas (TCGA) clinical database revealed that the GAU1/GALNT8 driver serves as an important indicative biomarker, and targeted silencing of GAU1 via the HKP-encapsulated method exhibited therapeutic efficacy in orthotopic xenografts. Our study presents a novel oncogenetic mechanism in which aberrant tuning of the chromatin state at specific chromosomal loci exposes factor-binding sites, leading to recruitment of trans-factor and activation of oncogenetic driver, thereby provide a novel alternative concept of chromatin dynamics in tumorigenesis.

This study was aimed to investigate the potential regulatory mechanism of high-content hydrogen water (HHW) in non-alcoholic fatty liver disease (NAFLD). A high-fat diet (HFD)-induced NAFLD mice model and cellular model were prepared. The serum levels of alanine transaminase (ALT), aspartate transaminase (AST), total cholesterol (TCH) and triglycerides (TG) were measured. The expression levels of representative five microRNA (miRNAs) (miR-103, miR-488, miR-136, miR-505 and miR-148a) in liver tissues were determined by quantitative real-time PCR (qRT-PCR). The target of miR-136 was validated by RNA immunoprecipitation (RIP) and pull-down assay. MiR-136, MEG3 and nuclear factor erythroid 2-related factor 2 (Nrf2) expression levels following cell treatment were detected in hepatocytes using qRT-PCR and Western blotting. Moreover, cell viability and TG content were conducted. MiR-136 was downregulated, MEG3 as well as Nrf2 was upregulated and serum lipid level was reduced in NAFLD mice model after HHW treatment, which exerted the same effect in cellular model. RIP and RNA pull-down assay confirmed that MEG2 was a downstream target of miR-136. What's more, HHW ameliorated lipid accumulation by regulating miR-136/MEG3/Nrf2 axis in vitro and in vivo. Hence, HHW alleviated NAFLD by downregulation of miR-136 through mediating Nrf2 via targeting MEG3.

Recent molecularly targeted approach gains advance in breast cancer treatment. However, the estimated 5-year survival rate has not met the desired expectation for improvement, especially for patients with triple-negative breast cancer (TNBC). Here we report that the lncRNA PVT1 promotes KLF5/beta-catenin signaling to drive TNBC tumorigenesis. PVT1 is upregulated in clinical TNBC tumors. Using genetic approaches targeting PVT1 in TNBC cells, we found that PVT1 depletion inhibited cell proliferation, colony formation, and orthotopic xenograft tumor growth. Mechanistically, PVT1 binds with KLF5 and increases its stability via BAP1, which upregulates beta-catenin signaling, resulting in enhanced TNBC tumorigenesis. PVT1, KLF5, and beta-catenin were also revealed to be co-expressed in clinical TNBC samples. Our findings uncover a new singaling pathway to mediate TNBC, and provide PVT1 as a new target for improving treatment of TNBC.

Intermediate-size noncoding RNAs (imsncRNAs) have been shown to play important regulatory roles in the development of several eukaryotic organisms. In this research, we selected imsnc761 as a research target. Expression analyses in a previous study showed that imsnc761 was downregulated in maturation-arrested testis tissue compared with the level in normal controls. In this study, we found that imsnc761 could interact with DEAD-box helicase 6 (DDX6) to induce NT2 cell apoptosis and proliferation inhibition via the p53 pathway. This interaction between imsnc761 and DDX6 also inhibited mitochondrial function and specific gene transcription and translation. To facilitate further research, we used label-free quantification method to analyse the associated differences in KEGG pathways and biological processes. This confirmed the changes of several specific pathways, which matched our molecular experimental results.

Osteosarcoma is a prevalent primary malignant tumor and long non-coding RNAs (lncRNAs) have been validated to modulate the osteosarcoma tumorigenesis. In present study, our research team investigates the role of a novel identified lncRNA DICER1-AS1 on the tumor progression and autophagy. Results showed that lncRNA DICER1-AS1 was up-regulated in osteosarcoma cells using microarray analysis and RT-PCR. Cellular functional experiments revealed that DICER1-AS1 knockdown suppressed the proliferation, migration, invasion and autophagy of osteosarcoma cells in vitro. Besides, DICER1-AS1 knockdown inhibited the protein expression levels of ATG5, LC3-II and Beclin 1, suggesting the inhibition on the autophagy of osteosarcoma cells. Moreover, miR-30b was verified to target 3'-UTR of DICER1-AS1 and ATG5 using bioinformatics tools and luciferase reporter assay or RNA-immunoprecipitation (RIP). Western blot showed that ATG5 protein expression was decreased in DICER1-AS1 knockdown and miR-30b mimics transfected cells, while increased in miR-30b inhibitor transfected cells, presenting a negative correlation with miR-30b and a positive correlation with DICER1-AS1. Finally, xenograft assay in vivo indicated that DICER1-AS1 knockdown inhibited the osteosarcoma tumor growth and protein expression level of ATG5. In summary, all the results conclude that DICER1-AS1 regulates the proliferation, invasion and autophagy of osteosarcoma via miR-30b/ATG5 axis, providing a novel insight for osteosarcoma tumorigenesis.

In the context of diabetes, obesity, and metabolic syndrome, the inflammatory signaling has critical roles in the pathogenesis of nonalcoholic fatty liver disease (NAFLD), but the underlying mechanisms remain poorly delineated. Herein, early and persistently elevated, proinflammatory cytokine HMGB1 expression was detected in a high-fat diet (HFD)-induced NAFLD model in C57BL/6 mice. The expression and extracellular release of HMGB1 was rapidly and dramatically induced by saturated palmitic acid in vitro. HFD-induced inflammatory response and liver function impairment were both mitigated after the inhibition of endogenous HMGB1 by neutralizing antibody in vivo. The up-regulation of HMGB1 was thought to be modified by dual channels: in the transcriptional level, it was regulated by JNK1/JNK2-ATF2 axis; post-transcriptionally, it was regulated by the microRNA (miR)-200 family, especially miR-429. miR-429 liver conditional knockout mice (miR-429Δhep), fed either a normal diet or an HFD, showed severe liver inflammation and dysfunction, accompanied by greater expression of HMGB1. Intriguingly, the up-regulation and release of HMGB1 could in turn self-activate TLR4-JNK1/JNK2-ATF2 signaling, thus forming a positive feedback. Our findings reveal a novel mechanism by which HMGB1 expression was regulated by both the JNK1/2-ATF2 axis and the miR-200 family, which provides a potential new approach for the treatment of NAFLD.-Chen, X., Ling, Y., Wei, Y., Tang, J., Ren, Y., Zhang, B., Jiang, F., Li, H., Wang, R., Wen, W., Lv, G., Wu, M., Chen, L., Li, L., Wang, H. Dual regulation of HMGB1 by combined JNK1/2-ATF2 axis with miR-200 family in nonalcoholic steatohepatitis in mice.

Ischemic stroke is related to a variety of physiological and pathological processes including autophagy and apoptosis. Growth arrest-specific 5 (GAS5), a long non-coding RNA (lncRNA), is known to negatively regulate cell survival and plays a key role in the pathogenesis of numerous diseases. However, the function and molecular mechanism of lncRNA GAS5 in ischemic stroke have not been reported. Real-time PCR was used to detect GAS5 and microRNA-137 (miR-137) expression in the brain tissues of mice underwent middle cerebral artery occlusion (MCAO) surgery and oxygen-glucose deprivation (OGD)-treated mouse primary brain neurons. Gain- or loss-of-function approaches were used to manipulate GAS5, miR-137, and Notch1. The mechanism of GAS5 in ischemic stroke was evaluated both in vivo and in vitro via bioinformatics analysis, MTT, flow cytometry, luciferase assay, RNA immunoprecipitation, and Western blot. GAS5 level was up-regulated and negatively correlated with miR-137 expression in MACO-injured brain and in OGR-stimulated primary brain neurons. GAS5 siRNA notably increased the cell viability, suppressed the activation of caspase-3 and cell apoptosis in neurons subjected to OGD. Furthermore, we also found that GAS5 functioned as a competing endogenous RNA (ceRNA) for miR-137 to regulate the de-repression of its endogenous target Notch1 and decrease neuron survival through inactivation of the Notch1 signaling pathway. Taken together, these findings indicate that GAS5 may promote the progression of ischemic stroke through acting as a ceRNA for miR-137 to mediate the Notch1 signaling pathway, which contributes to an extensive understanding of ischemic stroke and may provide novel therapeutic options for this disease.

A growing number of long non-coding RNAs (lncRNAs) have been found to be involved in diverse biological processes such as cell cycle regulation, embryonic development, and cell differentiation. However, limited knowledge is available concerning the underlying mechanisms of lncRNA functions. In this study, we found down-regulation of TCONS_00041960 during adipogenic and osteogenic differentiation of glucocorticoid-treated bone marrow mesenchymal stem cells (BMSCs). Furthermore, up-regulation of TCONS_00041960 promoted expression of osteogenic genes Runx2, osterix, and osteocalcin, and anti-adipogenic gene glucocorticoid-induced leucine zipper (GILZ). Conversely, expression of adipocyte-specific markers was decreased in the presence of over-expressed TCONS_00041960. Mechanistically, we determined that TCONS_00041960 as a competing endogenous RNA interacted with miR-204-5p and miR-125a-3p to regulate Runx2 and GILZ, respectively. Overall, we identified a new TCONS_00041960-miR-204-5p/miR-125a-3p-Runx2/GILZ axis involved in regulation of adipogenic and osteogenic differentiation of glucocorticoid-treated BMSCs.

The prognosis for bladder cancer patients with lymph node (LN) metastasis is dismal and only minimally improved by current treatment modalities. Elucidation of the molecular mechanisms that underlie LN metastasis may provide clinical therapeutic strategies for LN-metastatic bladder cancer. Here, we report that a long noncoding RNA LINC00958, which we have termed bladder cancer-associated transcript 2 (BLACAT2), was markedly upregulated in LN-metastatic bladder cancer and correlated with LN metastasis. Overexpression of BLACAT2 promoted bladder cancer-associated lymphangiogenesis and lymphatic metastasis in both cultured bladder cancer cell lines and mouse models. Furthermore, we demonstrate that BLACAT2 epigenetically upregulated VEGF-C expression by directly associating with WDR5, a core subunit of human H3K4 methyltransferase complexes. Importantly, administration of an anti-VEGF-C antibody inhibited LN metastasis in BLACAT2-overexpressing bladder cancer. Taken together, these findings uncover a molecular mechanism in the lymphatic metastasis of bladder cancer and indicate that BLACAT2 may represent a target for clinical intervention in LN-metastatic bladder cancer.