Reversion-inducing cysteine-rich protein with Kazal motifs interferes with epidermal growth factor receptor signaling

金沢大学がん研究所The reversion-inducing cysteine-rich protein with Kazal motifs (RECK) gene had been isolated as an antagonist to RAS signaling; however, the mechanism of its action is not clear. In this study, the effect of loss of RECK function was assessed in various ways and cell systems. Successive cell cultivation of mouse embryonic fibroblasts (MEFs) according to 3T3 protocol revealed that the germline knockout of RECK confers accelerated cell proliferation and early escape from cellular senescence associated with downregulation of p19 Arf, Trp53 and p21Cdkn1a. In contrast, short hairpin RNA-mediated depletion of RECK induced irreversible growth arrest along with several features of the Arf, Trp53 and Cdkn1a-dependent cellular senescence. Within 2 days of RECK depletion, we observed a transient increase in protein kinase B (AKT) and extracellular signal-regulated kinase (ERK) phosphorylation associated with an upregulated expression of cyclin D1, p19Arf, Trp53, p21Cdkn1a and Sprouty 2. On further cultivation, RAS, AKT and ERK activities were then downregulated to a level lower than control, indicating that RECK depletion leads to a negative feedback to RAS signaling and subsequent cellular senescence. In addition, we observed that epidermal growth factor receptor (EGFR) activity was transiently upregulated by RECK depletion in MEFs, and continuously downregulated by RECK overexpression in colon cancer cells. These findings indicate that RECK is a novel modulator of EGFR signaling. © 2011 Macmillan Publishers Limited All rights reserved

The β1-integrin-dependent function of RECK in physiologic and tumor angiogenesis

金沢大学がん研究所Vascular endothelial cells produce considerable amounts of matrix metalloproteinases (MMP), including MMP-2, MMP-9, and membrane type 1 (MT1)-MMP. However, little is known about the regulatory mechanisms of these protease activities exhibited during vascular development. A glycosylphosphatidylinositol-anchored glycoprotein, reversion-inducing cysteine-rich protein with Kazal motifs (RECK), has been shown to attenuate MMP-2 maturation by directly interacting with MT1-MMP. Here, we show that an angiogenic factor angiopoietin-1 induces RECK expression in human umbilical vein endothelial cells (HUVEC), and RECK depletion in these cells results in defective vascular tube formation and cellular senescence. We further observed that RECK depletion downregulates β1-integrin activation, which was associated with decreased autophosphorylation of focal adhesion kinase and increased expression of a cyclin-dependent kinase inhibitor p21CIP1. In agreement, significant downregulation of β1-integrin activity was observed in vascular endothelial cells in Reck-/- mouse embryos. In HUVECs, specific inhibition of MMP-2 significantly antagonized the effect of RECK depletion on β1-integrin signaling, cell proliferation, and tube elongation. Furthermore, we observed that hypervascular tumor-derived cell lines can induce high RECK expression in convoluted vascular endothelial cells, and this in turn supports tumor growth. Targeting RECK specifically in tumor-associated vascular endothelial cells resulted in tumor regression. Therefore, we propose that RECK in tumor vascular endothelial cells can be an interesting target of cancer treatment via abortion of tumor angiogenesis. ©2010 AACR

Social entrepreneurship: problems and ways of their solution

For modern constantly developing societies, it is normal to create categories in the process of the activity of the participants of socio-economic processes themselves. Practice is theoretical, and theory is pragmatic, because it creates those concepts in which «practice» exists and develops. Such a category is "social entrepreneurship", which is "umbrella" for a number of socio-economic phenomena. The general term for social entrepreneurship includes those types of entrepreneurial activity that contradict the traditional notion of entrepreneurship as an activity of independent economic entities aimed at maximizing their profits. The development of social entrepreneurship is an indicator of the quality of the business climate in the region and requires a set of measures to ensure the mechanism and access of non-governmental organizations to the provision of services in the social sphere, the provision of state support to socially-oriented non-profit organizations, and the promotion of the development of PPP practices in the social sphere

DUX4 is a multifunctional factor priming human embryonic genome activation

Double homeobox 4 (DUX4) is expressed at the early pre-implantation stage in human embryos. Here we show that induced human DUX4 expression substantially alters the chromatin accessibility of non-coding DNA and activates thousands of newly identified transcribed enhance-like regions, preferentially located within ERVL-MaLR repeat elements. CRISPR activation of transcribed enhancers by C-terminal DUX4 motifs results in the increased expression of target embryonic genome activation (EGA) genes ZSCAN4 and KHDC1P1. We show that DUX4 is markedly enriched in human zygotes, followed by intense nuclear DUX4 localization preceding and coinciding Kith minor EGA. DUX4 knockdown in human zygotes led to changes in the EGA transcriptome but did not terminate the embryos. We also show that the DUX4 protein interacts with the Mediator complex via the C-terminal KIX binding motif. Our findings contribute to the understanding of DUX4 as a regulator of the non-coding genome.Peer reviewe

MicroRNA-140 mediates RB tumor suppressor function to control stem cell-like activity through interleukin-6

We established an in vitro cell culture system to determine novel activities of the retinoblastoma (Rb) protein during tumor progression. Rb depletion in p53-null mouse-derived soft tissue sarcoma cells induced a spherogenic phenotype. Cells retrieved from Rb-depleted spheres exhibited slower proliferation and less efficient BrdU incorporation, however, much higher spherogenic activity and aggressive behavior. We discovered six miRNAs, including mmu-miR-18a, -25, -29b, -140, -337, and -1839, whose expression levels correlated tightly with the Rb status and spherogenic activity. Among these, mmu-miR-140 appeared to be positively controlled by Rb and to antagonize the effect of Rb depletion on spherogenesis and tumorigenesis. Furthermore, among genes potentially targeted by mmu-miR-140, Il-6 was upregulated by Rb depletion and downregulated by mmu-mir-140 overexpression. Altogether, we demonstrate the possibility that mmu-mir-140 mediates the Rb function to downregulate Il-6 by targeting its 3\u27-untranslated region. Finally, we detected the same relationship among RB, hsa-miR-140 and IL-6 in a human breast cancer cell line MCF-7. Because IL-6 is a critical modulator of malignant features of cancer cells and the RB pathway is impaired in the majority of cancers, hsa-miR-140 might be a promising therapeutic tool that disrupts linkage between tumor suppressor inactivation and pro-inflammatory cytokine response.Supplementary Table1 and Supplementary Table2: We offer the table data with an Excel fil

Rb Regulates DNA Damage Response and Cellular Senescence through E2F-Dependent Suppression of N-Ras Isoprenylation

がん抑制遺伝子不活性化によるがん化に対抗する生体の防御機構を解明. 京都大学プレスリリース. 2009-04-07.Oncogene-induced cellular senescence is well documented, but little is known about how infinite cell proliferation induced by loss of tumor suppressor genes is antagonized by cellular functions. Rb heterozygous mice generate Rb-deficient C cell adenomas that progress to adenocarcinomas following biallelic loss of N-ras. Here, we demonstrate that pRb inactivation induces aberrant expression of farnesyl diphosphate synthase, many prenyltransferases, and their upstream regulators sterol regulatory element-binding proteins (SREBPs) in an E2F-dependent manner, leading to enhanced isoprenylation and activation of N-Ras. Consequently, elevated N-Ras activity induces DNA damage response and p130-dependent cellular senescence in Rb-deficient cells. Furthermore, Rb heterozygous mice additionally lacking any of Ink4a, Arf, or Suv39h1 generated C cell adenocarcinomas, suggesting that cellular senescence antagonizes Rb-deficient carcinogenesis