Supplementary Materialsoncotarget-09-29193-s001. CTCL represents a promising novel therapeutic strategy that may be substantially potentiated by combination with BCL2 or HDAC inhibition. and is further characterized by erythroderma and bulky lymphadenopathy. Malignant T cells may comprise the majority of circulating T cells in patients with SS, with a median survival of 2 to 4 years [4C7]. The malignant T cells show constitutive activation and propensity for T-helper 2 cytokine production [8] that suppresses cell-mediated immunity and increases infection risk [1]. Unfortunately, CTCL remains generally incurable except in rare cases of allogeneic stem cell transplantation [9]. Overall response rates to single agent systemic therapies, including the retinoid bexarotene, and histone deacetylase (HDAC) inhibitors vorinostat and romidepsin, range between 20C45% and relapses are not uncommon [10, 11]. There is an unmet need for the treatment of advanced CTCL, and novel single or combination targeted therapies could be transformative. Next-generation sequencing efforts have improved our understanding of the genetic alterations driving CTCL and may help shape novel approaches to therapeutic targeting of this malignancy [12C17]. CTCL is distinctive from the vast majority of other malignancies in that somatic copy number variants (SCNVs) comprise 92% of all driver mutations present within DAPT biological activity CTCL cells, and the resulting genetic derangements can be clustered into DAPT biological activity three pathways: T cell activation, cell cycle dysregulation/apoptosis, and DNA structural dysregulation affecting gene expression [12]. Within these pathways, prioritization of Sema3g targeted therapies based on their specific mechanisms of action may be considered. Inhibition of the antiapoptotic protein B-cell lymphoma 2 (BCL2) was previously suggested as a targetable pathway based on common gene alterations that increase BCL2 activity and dependence, including and amplification, deletions and deletions [18C22]. We recently showed that venetoclax (ABT-199), a BCL2-selective inhibitor approved for relapsed or refractory chronic lymphocytic leukemia (CLL) with 17p deletion, efficiently induces apoptosis in patient-derived CTCL cells and this effect is synergistically potentiated by combination with HDAC inhibition [23, 24]. Mutational analysis in CTCL has also revealed 12 significant broad SCNVs [12]. The most common of these are amplifications on chromosome 8q that include the oncogene in 42.5% DAPT biological activity of leukemic CTCLs [12]. family genes play critical roles in cell growth and survival, DAPT biological activity and therefore the frequent amplification of in CTCL lends itself to therapeutic intervention [25]. Findings showing that NF-B is a potent transcriptional activator of the promoter [26] and that the NF-B pathway is constitutively active in CTCL [27] further suggest as a viable therapeutic target. Bromodomain and extra-terminal (BET) proteins are important in initiating and enhancing transcription and, in particular, the BET-protein BRD4 regulates key genes for cell cycle progression, including [25, 28, 29]. JQ1, a small-molecule BET inhibitor, prevents BRD4 binding and shows potent antiproliferative effects via downregulation of gene expression in several other hematologic and non-hematologic malignancies [30C35]. JQ1 has also been shown to have antiproliferative effects on CTCL cell lines [36]. However, the effects of BET inhibition on patient-derived CTCL cells or in combination with other targeted agents have not been reported previously. Herein, we show that BET targeting substantially decreases the viability of advanced patient-derived CTCL cells and that this effect can be synergistically potentiated by either BCL2 inhibition or HDAC inhibition. The effect is consistent across a spectrum of BET inhibitors: all four BET inhibitors tested (JQ1, ABBV-075, I-BET762, CPI-0610) demonstrate activity against CTCL cells, with ABBV-075 being the most potent. Combination of BET inhibition and HDAC inhibition, in particular, showed significant attenuation of and gene expression. Taken together, these data strongly suggest that BET inhibitors, alone and in combination with other agents, may allow for novel.
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We have previously demonstrated that Sox17 regulates cell cycle exit and
We have previously demonstrated that Sox17 regulates cell cycle exit and differentiation in oligodendrocyte progenitor cells. death had ceased. CNP-Sox17 mice showed increased Gli2 protein levels and Gli2+ cells in WM indicating that Sox17 promotes the generation of oligodendrocyte lineage cells through Hedgehog signaling. Sox17 overexpression prevented cell loss after lysolecithin-induced demyelination by increasing Olig2+ and CC1+ cells in response to injury. Furthermore Sox17 overexpression abolished the injury-induced increase in TCF7L2/TCF4+ cells and guarded oligodendrocytes from apoptosis by preventing decreases in Gli2 and Bcl-2 expression that were observed in WT lesions. Our study thus reveals a biphasic effect of Sox17 overexpression on cell survival and oligodendrocyte formation in the developing WM and that its potentiation of oligodendrocyte survival in the adult confers resistance to injury and myelin loss. This study demonstrates that overexpression of this transcription factor might be a viable protective strategy to mitigate the consequences of demyelination in the adult WM. Introduction Oligodendrogenesis from oligodendrocyte (OL) progenitor cells (OPCs) to mature myelinating OLs is usually spatially and temporally regulated by transcription factors under the control of multiple signaling pathways including canonical Wnt Sonic hedgehog Notch bone and morphogenetic proteins (Nicolay et al. SNS-032 2007 Fancy et al. 2009 Members of the SRY-box (Sox) transcription factors have emerged as crucial regulators of OL development and regeneration. Sox transcription factors that contain a conserved high mobility domain name that binds the DNA minor groove (Gubbay et al. 1990 are essential for the differentiation and maturation of OLs in the developing nervous system (Chew and Gallo 2009 Stolt and Wegner Sema3g 2010 Sox9 has an early function in maintaining the OPC populace (Stolt et al. 2003 while Sox10 is essential for terminal differentiation and myelin gene expression (Stolt et al. 2002 Inhibitory Sox factors 4 5 and 6 are also critical for timing OL SNS-032 specification and terminal differentiation (Potzner et al. 2007 Sox17 was found in the postnatal mouse white matter (WM) to be developmentally associated with the expression of multiple myelin genes SNS-032 and its pattern of expression supports a role in proliferative arrest (Sohn et al. 2006 In cultured OPCs Sox17 was shown to perform the dual functions of promoting OPC cycle exit and maturation to SNS-032 OLs (Sohn et al. 2006 Chew et al. 2011 Sox17 downregulation by siRNA increases OPC proliferation and attenuates differentiation. In addition Sox17 knockdown upregulates β-catenin and its targets cyclin D1 and Axin2. Conversely Sox17 overexpression (1) increases OPC cell cycle exit (2) decreases cyclinD1 levels and the levels and activity of b-catenin (3) promotes degradation of b-catenin (4) relieves Wnt repression of myelin protein levels and (5) enhances myelin promoter activity (Sohn et al. 2006 Chew et al. 2011 These findings identify Sox17 as a Wnt/β-catenin antagonist in the lineage and suggest that ectopic Sox17 expression may promote OL formation through Wnt modulation. To study the function of Sox17 in OLs gene promoter. The (2′ 3 nucleotide 3′- phosphodiesterase) promoter has been shown to provide strong OL lineage-specific expression in the WM (Yuan et al. 2002 We wanted to determine whether Sox17 overexpression would lead to increased development of OLs. Since demyelination upregulates Wnt signaling (Fancy et al. 2009 we also wanted to determine whether Sox17 overexpression could block Wnt signaling and alter the course of demyelination in the adult WM. Our present analysis constitutes the first study of Sox17 function in WM. Sox17 overexpression increased WM levels of the Hedgehog mediator Gli2 regulated β-catenin-expressing cells and development of the OL lineage in biphasic fashion and ultimately produced supranormal numbers of OL cells. As lysolecithin-induced demyelination injury failed to increase cell death or affect MBP levels Gli2 and the antiapoptotic protein Bcl-2 in the adult CNP-Sox17 mouse we propose that Sox17 potentiates Hedgehog signaling in its attenuation of WM damage. Materials and Methods Plasmid construct and generation of transgenic mice. The plasmid for generating transgenic mice was constructed as follows: (1) the CNP promoter plasmid CNP4.2 (Gravel et al. 1998 was altered by introducing restriction enzyme AgeI site at HindIII site to obtain CNP3.9 vector; (2) a full length of IRES-ZsGreen1 with added SNS-032 AgeI site at 5′ and XhoI site at 3′ was.