This SuperSeries is composed of the SubSeries listed below.
Sparstolonin B inhibits pro-angiogenic functions and blocks cell cycle progression in endothelial cells.
Specimen part, Treatment
View SamplesChromosome 5q deletions (del(5q)) are common in high-risk (HR) Myelodysplastic Syndrome (MDS) and Acute Myeloid Leukemia (AML); however, the gene regulatory networks that sustain these aggressive diseases are unknown. Reduced miR-146a expression in del(5q) HR-MDS/AML and miR-146a-/- hematopoietic stem/progenitor cells (HSPC) results in TRAF6/NF- activation. Increased survival and proliferation of HSPC from miR-146alow HR-MDS/AML is sustained by a neighboring haploid gene, SQSTM1 (p62), expressed from the intact 5q allele. Overexpression of p62 from the intact allele occurs through NF-B-dependent feedforward signaling mediated by miR-146a deficiency. p62 is necessary for TRAF6-mediated NF-B signaling, as disrupting the p62-TRAF6 signaling complex results in cell cycle arrest and apoptosis of MDS/AML cells. Thus, del(5q) HR-MDS/AML employs an intrachromosomal gene network involving loss of miR-146a and haploid overexpression of p62 via NF-B to sustain TRAF6/NF-B signaling for cell survival and proliferation. Interfering with the p62-TRAF6 signaling complex represents a therapeutic option in miR-146a-deficient and aggressive del(5q) MDS/AML.
Myeloid malignancies with chromosome 5q deletions acquire a dependency on an intrachromosomal NF-κB gene network.
Sex, Specimen part
View SamplesSparstolonin B is a novel bioactive compound isolated from Sparganium stoloniferum, an herb historically used in Traditional Chinese Medicine as an anti-tumor agent. SsnB has previously demonstrated anti-angiogenic properties. In functional assays, SsnB inhibited endothelial cell tube formation (Matrigel method) and cell migration (Transwell method) in a dose-dependent manner.
Sparstolonin B inhibits pro-angiogenic functions and blocks cell cycle progression in endothelial cells.
Specimen part, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
No associated publication
Cell line
View SamplesSparstolonin B is a novel bioactive compound isolated from Sparganium stoloniferum, an herb historically used in Traditional Chinese Medicine as an anti-tumor agent. SsnB has previously demonstrated anti-angiogenic properties. In functional assays, SsnB inhibited endothelial cell tube formation (Matrigel method) and cell migration (Transwell method) in a dose-dependent manner.
Sparstolonin B inhibits pro-angiogenic functions and blocks cell cycle progression in endothelial cells.
Specimen part, Treatment
View SamplesCDK8 Mediator kinase is amplified and overexpressed in colon cancers; elevated CDK8 expression is associated with shorter patient survival. Nevertheless, CDK8 kinase inhibitors do not generally suppress colon cancer growth. We addressed this paradox by investigating the effects of CDK8 knockdown or a CDK8 kinase inhibitor on tumor growth at primary and metastatic sites. CDK8 knockdown or inhibition had no significant effect on primary tumors but suppressed the growth of hepatic metastases in murine and human colon cancer models. The effect of CDK8 inhibition on liver metastasis is mediated by upregulation of matrix metalloproteinase (MMP) inhibitor TIMP3 and downregulation of several MMPs.
No associated publication
No sample metadata fields
View SamplesBortezomib (Velcade) is widely used for the treatment of various human cancers, however, its mechanisms of action are not fully understood, particularly in myeloid malignancies. Bortezomib is a selective and reversible inhibitor of the proteasome. Paradoxically, we find that Bortezomib induces proteasome-independent degradation of TRAF6 protein, but not mRNA, in Myelodysplastic syndrome (MDS) and Acute Myeloid Leukemia (AML) cell lines and primary cells. The reduction in TRAF6 protein coincides with Bortezomib-induced autophagy, and subsequently with apoptosis in MDS/AML cells. RNAi-mediated knockdown of TRAF6 sensitized Bortezomib-sensitive and -resistant cell lines, underscoring the importance of TRAF6 in Bortezomib-induced cytotoxicity. Bortezomib-resistant cells expressing an shRNA targeting TRAF6 were resensitized to the cytotoxic effects of Bortezomib due to down-regulation of the proteasomal subunit alpha-1 (PSMA1). To uncover the molecular consequences following loss of TRAF6 in MDS/AML cells, we applied gene expression profiling and identified an apoptosis gene signature. Knockdown of TRAF6 in MDS/AML cell lines or patient samples resulted in rapid apoptosis and impaired malignant hematopoietic stem/progenitor function. In summary, we describe novel mechanisms by which TRAF6 is regulated through Bortezomib/autophagy-mediated degradation and by which it alters MDS/AML sensitivity to Bortezomib by controlling PSMA1 expression.
Cytotoxic effects of bortezomib in myelodysplastic syndrome/acute myeloid leukemia depend on autophagy-mediated lysosomal degradation of TRAF6 and repression of PSMA1.
Treatment
View SamplesCDK8 Mediator kinase is amplified and overexpressed in colon cancers; elevated CDK8 expression is associated with shorter patient survival. Nevertheless, CDK8 kinase inhibitors do not generally suppress colon cancer growth. We addressed this paradox by investigating the effects of CDK8 knockdown or a CDK8 kinase inhibitor on tumor growth at primary and metastatic sites. CDK8 knockdown or inhibition had no significant effect on primary tumors but suppressed the growth of hepatic metastases in murine and human colon cancer models. The effect of CDK8 inhibition on liver metastasis is mediated by upregulation of matrix metalloproteinase (MMP) inhibitor TIMP3 and downregulation of several MMPs.
No associated publication
Cell line
View SamplesReprogrammed somatic cells offer a valuable source of pluripotent cells that have the potential to differentiate into many cells types and provide a new tool for regenerative medicine. In the present study we differentiated induced pluripotent stem cells (iPS cells) into hepatic cells. We first showed that mouse iPS cells could from a complete liver in mouse embryo (E14.5) including hepatocytes, endothelial cells, sinusoidal cells and resident macrophages. We then designed a highly efficient hepatocyte differentiation protocol using defined factors on human embryonic stem cells (ES cells). This protocol was found to generate more than 80% albumin expressing cells that show hepatic functions and express most of liver genes as shown by microarray analyses. Similar results were obtained when human iPS cells were induced to differentiate following the same procedure.
Highly efficient generation of human hepatocyte-like cells from induced pluripotent stem cells.
Specimen part, Cell line
View SamplesThe availability of pluripotent stem cells offers the possibility of using such cells to model hepatic disease and development. With this in mind, we previously established a protocol that facilitates the differentiation of both human embryonic stem cells and induced pluritpotent cells into cells with hepatocyte characteristics. The use of highly defined culture conditions and the avoidance of feeder cells or embryoid bodies allowed synchronous and reproducible differentiation to occur. The differentiation toward a hepatocytelike fate appeared to recapitulate many of the stages normally associated with the formation of hepatocytes in vivo. In the current study we addressed the feasibility of using human pluripotent stem cells to probe the molecular mechanisms underlying human hepatocyte differentiation. We demonstrate i) that human ES cells express a number of mRNAs that characterize each stage in the differentiation process, ii) that gene expression can be efficiently depleted throughout the differentiation time course using shRNAs expressed from lentiviruses, and iii) that the nuclear hormone receptor HNF4a is essential for specification of human hepatic progenitor cells by establishing expression of the network of transcription factors that control hepatocyte cell fate.
HNF4A is essential for specification of hepatic progenitors from human pluripotent stem cells.
Specimen part, Time
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