Epigenetic inhibition of lncRNA GMDS-AS1 by methyltransferase ESET promoted cell viability and metastasis of hepatocellular carcinoma

Background Long noncoding RNA (lncRNAs) GMDS-AS1 has been reported as a tumor regulator in tumor growth and metastasis, but its effect in hepatocellular carcinoma (HCC) remains unclear. ESET, a histone H3K9 methyl-transferase, is involved in epigenomic regulation of tumor progression in multiple cancers. However, the correlation between ESET and lncRNA in HCC is less reported. Methods Quantitative real-time PCR (qRT-PCR) was taken to determine the expression of ESET and GMDS-AS1. Western blot was taken to determine the target protein levels of ESET and GMDS-AS1. Online database and bioinformatics analysis were used to screen abnormally expressed genes. Luciferase assay was performed to confirm the binding of GMDS-AS1 and PSMB1. Ki67 and Edu were used for evaluated the proliferation of tumor cells. ChIP assay was performed to verify the relationship between H3K9me1 and lncRNA GMDS-AS1 promoter. Transwell was taken to determine the migration and invasion ability of tumor cells. CCK-8 was used for determining the viability of tumor cells. Flow cytometry was performed to detect the cell cycle of tumor cells. Results The expression of GMDS-AS1 was decreased and the expression of ESET was increased in HCC. GMDS-AS1 inhibition contributed to tumor development, and this effect was closely related to epigenetic inhibition of GMDS-AS1 by ESET. PSMB1, a downstream target of GMDS-AS1, promoted the tumor proliferation and was negatively regulated by GMDS-AS1. Conclusion Our result demonstrates anti-tumorigenic traits of lncRNA GMDS-AS1 in HCC and explains its pattern of regulation mediated by ESET. Our work unmasked an essential role of GMDS-AS1 in HCC progression and detected a novel pathway for ESET to promote HCC (AU)

Epigenetic inhibition of lncRNA GMDS-AS1 by methyltransferase ESET promoted cell viability and metastasis of hepatocellular carcinoma.

BACKGROUND: Long noncoding RNA (lncRNAs) GMDS-AS1 has been reported as a tumor regulator in tumor growth and metastasis, but its effect in hepatocellular carcinoma (HCC) remains unclear. ESET, a histone H3K9 methyl-transferase, is involved in epigenomic regulation of tumor progression in multiple cancers. However, the correlation between ESET and lncRNA in HCC is less reported. METHODS: Quantitative real-time PCR (qRT-PCR) was taken to determine the expression of ESET and GMDS-AS1. Western blot was taken to determine the target protein levels of ESET and GMDS-AS1. Online database and bioinformatics analysis were used to screen abnormally expressed genes. Luciferase assay was performed to confirm the binding of GMDS-AS1 and PSMB1. Ki67 and Edu were used for evaluated the proliferation of tumor cells. ChIP assay was performed to verify the relationship between H3K9me1 and lncRNA GMDS-AS1 promoter. Transwell was taken to determine the migration and invasion ability of tumor cells. CCK-8 was used for determining the viability of tumor cells. Flow cytometry was performed to detect the cell cycle of tumor cells. RESULTS: The expression of GMDS-AS1 was decreased and the expression of ESET was increased in HCC. GMDS-AS1 inhibition contributed to tumor development, and this effect was closely related to epigenetic inhibition of GMDS-AS1 by ESET. PSMB1, a downstream target of GMDS-AS1, promoted the tumor proliferation and was negatively regulated by GMDS-AS1. CONCLUSION: Our result demonstrates anti-tumorigenic traits of lncRNA GMDS-AS1 in HCC and explains its pattern of regulation mediated by ESET. Our work unmasked an essential role of GMDS-AS1 in HCC progression and detected a novel pathway for ESET to promote HCC.

Wogonin induces apoptosis and endoplasmic reticulum stress in HL-60 leukemia cells through inhibition of the PI3K-AKT signaling pathway.

Wogonin is a flavonoid isolated from Scutellaria baicalensis root and has multiple pharmacological effects, including anticancer effects. Recent studies have shown that wogonin induces cell cycle arrest and reverses multi-drug resistance in the human K562 leukemia cell line. However, its pharmacological function in the apoptosis of leukemia cells remains unknown. Therefore, we hypothesized that wogonin can induce apoptosis in the HL-60 leukemia cell line. In the present study, the HL-60 cells were treated with different doses of wogonin (0-150 µM). Wogonin inhibited the viability of HL-60 cells in a dose-dependent and time-dependent manner. Flow cytometry and analyses of caspase and PARP-1 activation and the Bax/Bcl-2 ratio, demonstrated that the cytotoxic effect of wogonin on HL-60 cells was mediated by caspase-dependent and mitochondrial-dependent apoptosis. Wogonin also induced the expression of certain members of the endoplasmic reticulum (ER) stress pathway (CHOP, GRP94 and GRP78) and the activation of multiple branches of ER stress transducers (IRE1α, PERK-eIF2α and ATF6) in the HL-60 cells. In addition, wogonin reduced the phosphorylation of PI3K and AKT in the HL-60 cells. Furthermore, constitutive activation of AKT induced by adenoviral vectors inhibited the pro-apoptotic effects and ER stress induced by wogonin in the HL-60 cells. In summary, our results indicated that wogonin induced apoptosis and ER stress in HL-60 cells, which was mediated by the inhibition of the PI3K-AKT signaling pathway.

Activation of Notch signal pathway is associated with a poorer prognosis in acute myeloid leukemia.

OBJECTIVE: Notch signal pathway plays a fundamental role in regulating haematopoietic development. It is also an important mediator of growth and survival in several cancer types, with Notch pathway genes functioning as oncogenes or tumor suppressors in different cancers. However, the clinical role of Notch signal pathway in acute myeloid leukemia (AML) remains unclear. METHODS: To address this problem, we investigated the gene expression levels of Notch signal pathway members (Notch1, Jagged1 and Delta1) in bone marrow mononuclear cells by real-time quantitative PCR in a cohort of 100 patients with newly diagnosed de novo AML and normal marrow donors. The prognostic values of the three molecules in AML were also analyzed. RESULTS: Comparing with the normal controls, we show the transcriptional up-regulation of Notch1, Jagged1 and Delta1 in the bone marrow of AML patients with statistic differences (P = 0.008, 0.01 and 0.01, respectively). In addition, univariate analysis of factors associated with relapse-free survival and overall survival showed a significantly shorter survival in the patients with unfavorable karyotype, higher Notch1 expression, higher Jagged1 expression, or higher Delta1 expression. Moreover, Cox proportional hazards multivariate analysis of the univariate predictors identified karyotype and gene expression levels of Notch1, Jagged1 and Delta1 as independent prognostic factors for relapse-free survival and overall survival. Furthermore, the prognostic significance of Notch1, Jagged1 and Delta1 expression was more obvious in the subgroup of patients with intermediate-risk cytogenetics. CONCLUSION: Taken together, our data suggest for the first time that the activation of Notch pathway may indicate a poor prognosis in AML. Especially, Notch1, Jagged1 and Delta1 expression may be relevant prognostic markers in intermediate risk AML.

A novel biosynthetic hybrid scaffold seeded with olfactory ensheathing cells for treatment of spinal cord injuries.

BACKGROUND: Implantation of tissue-engineered scaffolds is one of the most promising therapeutic strategies for inducing nerve regenerations following spinal cord injuries. In this paper, we report a novel bioengineered hybrid scaffold comprised of three major extracellular matrix (ECM) proteins. METHODS: ECM-scaffolds (ECM-S) were prepared by gelling fibrinogen, fibronectin and laminin using fresh rat plasma. Olfactory ensheathing cells (OECs) were isolated from fresh rat olfactory mucosa, purified under differential adhesion, and assessed by immunofluorescent staining. OECs were seeded onto ECM-S and cultured. The effects of the scaffolds on the seeded cells were detected using the immunofluorescent staining, Western blotting, scanning electron microscopy and transmission electron microscopy. RESULTS: Tissue-engineered ECM-S could be easily molded into mat-like or cylindrical shapes and gelled by addition of fresh plasma. Observations by electron microscopy show that the ECM-S forms a stable three-dimensional porous network. Studies on the effects of the ECM-S on the biological behaviors of OECs in vitro indicate that the scaffold can promote OEC adhesion, proliferation and process extensions. Additionally, OECs seeded on the scaffold maintained the expression of nerve growth factor, matrix metalloproteinase-3 and matrix metalloproteinase-9. CONCLUSION: We developed a biosynthetic hybrid gel which could be used as a scaffold for OEC transplantation; this gel can promote nerve regeneration following spinal cord injuries.

Nuclear expression of YB-1 in diffuse large B-cell lymphoma: correlation with disease activity and patient outcome.

The aim of this study is to investigate the correlations among Y-box binding protein-1 (YB-1) and P-glycoprotein(P-gp) and their prognostic significance in diffuse large B-cell lymphoma (DLBCL). The expression of YB-1 and P-gp was examined immunohistochemically on 68 patients with DLBCL who were treated from 2003 to 2005. Samples were paraffin-embedded newly diagnosed DLBCL tissues taken from the surgical specimens before adjuvant chemotherapy. We determined the prognostic significance of YB-1 and its relationship with P-gp in patients with DLBCL. Of the 68 tumors examined, 42 (61.8%) were positive for YB-1 expression in the nucleus. The nuclear expression of YB-1 was significantly associated with clinical stages, bone marrow involvement, extra nodal involvement, and poor response to chemotherapy. No associations were observed between P-gp and clinical features, in context of the poor response to chemotherapy. Nuclear expression of YB-1 was correlated significantly with increased expression of P-gp patients with a nuclear YB-1 tumor had a poorer prognosis than did those with a cytoplasmic YB-1 tumor in all of the DLBCL patients (P = 0.035). Thus, correlation of YB-1 and P-gp emerged as a possible biomarker for unfavorable prognosis in DLBCL. It may provide useful information for clinicians to determine the appropriate therapy for each type of DLBCL.

Vector-based RNAi approach to isoform-specific downregulation of vascular endothelial growth factor (VEGF)165 expression in human leukemia cells.

Vascular endothelial growth factor (VEGF) plays a critical role during normal embryonic angiogenesis and also in the pathological angiogenesis that occurs in a number of diseases, including cancer. K562 human leukemia cells overexpress VEGF, with a shift in isoform production from membrane-bound VEGF189 to the more soluble VEGF165. In the present study, three 19 bp reverse repeated motifs targeting exons 5 and 7 boundary of VEGF165 gene sequence with 9 bp spacer were synthesized and cloned into eukaryotic expression plasmid pGenesil-1 containing U6 shRNA promoter and termination signal of RNA polymerase. The recombinant plasmids pGenesil-VR1, pGenesil-VR2, pGenesil-VR3 and pGenesil-con (plasmid containing random DNA fragment) were transfected into K562 cells, respectively, through lipofectamine reagent. A vector-based small interfering RNA(SiRNA) inhibited VEGF165 mRNA expression by 72% and protein production by 67% in K562 cells. Human microvascular endothelial cell migration induced by conditioned medium from VEGFsi-transfected K562 cells was significantly less than that induced by conditioned medium from K562 cells and control vector-transfected K562 cells. Furthermore, the VEGF shRNA dramatically suppressed tumor angiogenesis and tumor growth in a K562 s.c. xenograft model. Vessel density as assessed by vWF immunohistochemical analysis was also decreased. This strategy provides a novel tool to study the function of various VEGF isoforms and may contribute to VEGF-specific treatment in cancer.