Eri Nishikawa

Apoptosis induction by antisense oligonucleotides against miR-17-5p and miR-20a in lung cancers overexpressing miR-17-92.

Amplification and overexpression of the miR-17-92 microRNAs (miRNA) cluster at 13q31.3 has recently reported, with pointers to functional involvement in the development of B-cell lymphomas and lung cancers. In the present study, we show that inhibition of miR-17-5p and miR-20a with antisense oligonucleotides (ONs) can induce apoptosis selectively in lung cancer cells overexpressing miR-17-92, suggesting the possibility of ‘OncomiR addiction’ to expression of these miRNAs in a subset of lung cancers. In marked contrast, antisense ONs against miR-18a and miR-19a did not exhibit such inhibitory effects, whereas inhibition of miR-92-1 resulted in only modest reduction of cell growth, showing significant distinctions among miRNAs of the miR-17-92 cluster in terms of their roles in cancer cell growth. During the course of this study, we also found that enforced expression of a genomic region, termed C2, residing 3′ to miR-17-92 in the intron 3 of C13orf25 led to marked growth inhibition in association with double stranded RNA-dependent protein kinase activation. Finally, this study also revealed that the vast majority of C13orf25 transcripts are detected as Drosha-processed cleavage products on Northern blot analysis and that a novel polyadenylation site is present 3′ to the miR-17-92 cluster and 5′ to the C2 region. Taken together, the present findings contribute towards better understanding of the oncogenic roles of miR-17-92, which might ultimately lead to the future translation into clinical applications.

miR-375 Is Activated by ASH1 and Inhibits YAP1 in a Lineage-Dependent Manner in Lung Cancer

Lung cancers with neuroendocrine (NE) features are often very aggressive but the underlying molecular mechanisms remain elusive. The transcription factor ASH1/ASCL1 is a master regulator of pulmonary NE cell development that is involved in the pathogenesis of lung cancers with NE features (NE-lung cancers). Here we report the definition of the microRNA miR-375 as a key downstream effector of ASH1 function in NE-lung cancer cells. miR-375 was markedly induced by ASH1 in lung cancer cells where it was sufficient to induce NE differentiation. miR-375 upregulation was a prerequisite for ASH1-mediated induction of NE features. The transcriptional coactivator YAP1 was determined to be a direct target of miR-375. YAP1 showed a negative correlation with miR-375 in a panel of lung cancer cell lines and growth inhibitory activities in NE-lung cancer cells. Our results elucidate an ASH1 effector axis in NE-lung cancers that is functionally pivotal in controlling NE features and the alleviation from YAP1-mediated growth inhibition.

Recurrent MYB rearrangement in blastic plasmacytoid dendritic cell neoplasm

Lymphoproliferative Disorders Team, Centre de Recherche des Cordeliers, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 1138, Centre de Recherche des Cordeliers, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, UMR_S 1138, Centre de Recherche des Cordeliers, Paris, France; Service d’Hématologie Biologique, GH Pitié-Salpêtrière, Paris, France; Service de Biostatistique et Informatique Médicale, Hôpital Saint Louis, Paris, France.; Département de génétique, GH Pitié-Salpêtrière, Paris, France; INSERM U1170, Institut Gustave Roussy, Villejuif, France; Département d’Hématologie, Hôpital Becquerel, Rouen, France; Pôle d’Hématologie, Hôpital Brabois, Vandoeuvre-les-Nancy, France; Service d’Hématologie Clinique, Hôpital d’Argenteuil, Argenteuil, France and Karyopharm Therapeutics, Newton, MA, USA E-mail: santos.susin@crc.jussieu.fr or florence.nguyen-khac@psl.aphp.fr These authors contributed equally to this work. Senior coauthorship.

Treatment responses for disseminated intravascular coagulation in 25 children treated with recombinant thrombomodulin: A single institution experience

INTRODUCTION Recombinant thrombomodulin (rTM), which degrades factors Va and VIIIa by activating protein C, has been developed as a new drug for treating disseminated intravascular coagulation (DIC). MATERIALS AND METHODS Since July 2009, we have treated 25 children with DIC using rTM (380 U/kg/day, or 130 U/kg/day for newborns) as a first-line therapy. Median duration of rTM administration was 5 consecutive days (range, 2-13 days). We employed DIC criteria of the Japan Welfare and Health Ministry. The first day on which rTM treatment was given was defined as day 1. RESULTS Median patients age was 3 years. Underlying diseases were hematological disorders (n=13) and severe infection (n=12). Overall, 20 of the 25 patients had recovered from DIC by day 7 and 22 of the 25 patients remained alive at day 28. Median Pediatric Logistic Organ Dysfunction score improved from 11 on day 1 to 2 on day 7 (p=0.009). Laboratory data (median) on day 7 (prothrombin time (PT) ratio, 1.15; fibrin and fibrinogen degradation products (FDP), 9.6 mg/l; D-dimer, 1.6 mg/l FEU; antithrombin, 112%; protein C, 105%) were significantly improved compared to results on day 1 (PT ratio, 1.39; FDP, 21.6 mg/l; D-dimer, 6.4 mg/l FEU; antithrombin, 86%; protein C, 54%). Whereas, 5 patients failed to respond and serious bleeding events were observed in 2 newborns. CONCLUSION The efficacy of rTM cannot be assessed from the present dataset, due to several limitations such as the small heterogenous patient cohort, and the lack of age- and disease-matched controls. Nevertheless, this case-series remains important in terms of enabling further prospective control studies to evaluate the efficacy of rTM in children.

Long-term outcomes of 95 children with moderate aplastic anemia treated with horse antithymocyte globulin and cyclosporine.

Currently, the standard management of moderate aplastic anemia (MAA) has not been well described, although the superiority of the combination of antithymocyte globulin (ATG) and cyclosporine (CyA) over CyA alone has been demonstrated in terms of hematological responses and failure‐free survival (FFS).

Development of clinical paroxysmal nocturnal haemoglobinuria in children with aplastic anaemia

The clinical significance of paroxysmal nocturnal haemoglobinuria (PNH) in children with aplastic anaemia (AA) remains unclear. We retrospectively studied 57 children with AA between 1992 and 2010. During the follow‐up, five patients developed clinical PNH, in whom somatic PIGA mutations were detected by targeted sequencing. The 10‐year probability of clinical PNH development was 10·2% (95% confidence interval, 3·6–20·7%). Furthermore, the detection of minor PNH clones by flow cytometry at AA diagnosis was a risk factor for the subsequent development of clinical PNH. These patients with PNH clones at AA diagnosis should undergo periodic monitoring for potential clinical PNH development.

Integration Mapping of piggyBac-Mediated CD19 Chimeric Antigen Receptor T Cells Analyzed by Novel Tagmentation-Assisted PCR

Insertional mutagenesis is an important risk with all genetically modified cell therapies, including chimeric antigen receptor (CAR)-T cell therapy used for hematological malignancies. Here we describe a new tagmentation-assisted PCR (tag-PCR) system that can determine the integration sites of transgenes without using restriction enzyme digestion (which can potentially bias the detection) and allows library preparation in fewer steps than with other methods. Using this system, we compared the integration sites of CD19-specific CAR genes in final T cell products generated by retrovirus-based and lentivirus-based gene transfer and by the piggyBac transposon system. The piggyBac system demonstrated lower preference than the retroviral system for integration near transcriptional start sites and CpG islands and higher preference than the lentiviral system for integration into genomic safe harbors. Integration into or near proto-oncogenes was similar in all three systems. Tag-PCR mapping is a useful technique for assessing the risk of insertional mutagenesis.

Comparison of capacities to maintain hematopoietic stem cells among different types of stem cells derived from the placenta and umbilical cord

Introduction Cord blood is utilized as a useful source of cells for hematopoietic stem cell transplantation, but this can be problematic because there is a high rate of graft failure compared to when other graft sources are used. A previous study successfully avoided graft failure by simultaneously grafting cord blood and bone marrow mesenchymal stem cells (MSCs) that are considered to function in the hematopoietic stem cell niche of the bone marrow. Organs of the fetal life support system such as the placenta and umbilical cord, which are discarded after delivery, contain an abundance of MSCs as well as cells that function in the hematopoietic stem cell niche. By identifying and collecting such cells and subsequently co-transplanting them with cord blood, an improvement in graft survival can be anticipated. Methods Three types of stem cells, amnion epithelial stem cells (AM-Epi), amnion mesenchymal stem cells (AM-Mes), and Whartons jelly (WJ)-MSCs, all of which can be isolated and cultured from the placenta amnion or umbilical cord WJ, were investigated for the expression of hematopoietic stem cell niche markers and for their capabilities to maintain hematopoietic stem cells when co-cultured with cord blood hematopoietic stem cells. Results All types of isolated cells showed profiles that met the MSC minimal criteria according to surface marker analysis. In addition, all cell types expressed the hematopoietic stem cell niche marker stromal cell-derived factor-1 (SDF-1) (in order: AM-Epi > WJ-MSCs ≫ AM-Mes), although the expression declined with further passaging. After 5 days of co-culturing with cord blood CD34+ cells, the percentages of CD34+, CD45− cells were: AM-Epi 37.8%, AM-Mes 38.8%, WJ-MSCs 27.3%, and fibroblasts 27.4%; and the number of CFU-GM colonies were: AM-Epi 255.5 ± 21.6, AM-Mes 246.3 ± 28.5, WJ-MSCs 118.3 ± 11.8, fibroblasts 147.8 ± 19.0, and NC 121.3 ± 6.5. Statistical analyses demonstrated that AM-Epi and AM-Mes produced significantly greater numbers of CFU-GM compared to WJ-MSC, fibroblasts, or NC (p < 0.05). Conclusions These findings indicated that cells derived from the fetal life support system such as AM-Epi and AM-Mes can be anticipated as potential cell sources for clinical application in cell therapies for the purpose of enhancing graft survival during hematopoietic stem cell transplantation.

Abstract 3992: Roles of ASH1-miR-375 pathway in development of lung cancers with neuroendocrine features

Lung cancers with neuroendocrine (NE) features are often very aggressive, though the underlying molecular mechanisms have not been clearly elucidated. We previously reported that the basic helix-loop-helix protein, achaete-scute homologue 1 (ASH1/ASCL1), a master regulator of pulmonary neuroendocrine cell development, is crucially involved in the pathogenesis of lung cancers with neuroendocrine features (NE-lung cancers). In the present study, we searched for miRNAs regulated by ASH1 in order to gain insight into the involvement of miRNAs downstream of ASH1 in NE-lung cancer pathogenesis. We consequently found that introduction of ASH1 into A549 cells markedly induced miR-375 and down-regulated miR-200b. Interestingly, these two miRNAs inversely affected cell-cell interaction and cell motility, and they together conferred looser cell attachment and a more motile feature. miR-375 was found to be directly transactivated by ASH1. Global gene expression analysis using miR-375-introduced A549 cells and the subsequent pathway analysis using the Ingenuity IPA software revealed altered gene expressions in several cancer-related pathways (e.g., cellular movement and morphology). Interestingly, we also found that miR-375 alone can induce NE differentiation markers in A549 cells and that miR-375 is required to elicit ASH1-indued NE features. In accordance with these findings in vitro, clear induction of NE features as well as enhanced tumor growth was observed in xenografts of A549 cells stably expressing miR-375. We further found that a transcriptional co-activator YAP1 is most significantly repressed by miR-375 through recognition of its two miR-375 binding sites. A positive correlation between ASH1 and miR-375 as well as a negative correlation between miR-375 and YAP1 were observed in lung cancers, indicating the ASH1-miR-375-YAP1 regulatory pathway is indeed functionally implemented in lung cancer cells. In addition, we found that growth-regulatory functions of YAP1 is cell-lineage dependent in lung cancer cell lines. In conclusion, the present study identified the ASH1-miR-375 axis, providing clues for a better understanding of the molecular and cellular biological roles of ASH1-centered microRNA regulatory networks in the pathogenesis of NE-lung cancers. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3992. doi:10.1158/1538-7445.AM2011-3992