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Supplementary Table S1 from Histone Deacetylase Inhibitors (HDI) Cause DNA Damage in Leukemia Cells: A Mechanism for Leukemia-Specific HDI-Dependent Apoptosis?

Supplementary Figure Legends from Histone Deacetylase Inhibitors (HDI) Cause DNA Damage in Leukemia Cells: A Mechanism for Leukemia-Specific HDI-Dependent Apoptosis?

Supplementary Figures S1 & S2 from Histone Deacetylase Inhibitors (HDI) Cause DNA Damage in Leukemia Cells: A Mechanism for Leukemia-Specific HDI-Dependent Apoptosis?

Supplementary Table 4 from Reactive Oxygen Species, DNA Damage, and Error-Prone Repair: A Model for Genomic Instability with Progression in Myeloid Leukemia?

Supplementary Table 3 from Reactive Oxygen Species, DNA Damage, and Error-Prone Repair: A Model for Genomic Instability with Progression in Myeloid Leukemia?

Myelodysplastic syndromes (MDS) comprise a heterogeneous group of disorders characterized by ineffective hematopoiesis, with an increased propensity to develop acute myelogenous leukemia (AML). The molecular basis for MDS progression is unknown, but a key element in MDS disease progression is loss of chromosomal material (genomic instability). Using our two-step mouse model for myeloid leukemic disease progression involving overexpression of human mutant NRAS and BCL2 genes, we show that there is a stepwise increase in the frequency of DNA damage leading to an increased frequency of error-prone repair of double-strand breaks (DSB) by nonhomologous end-joining. There is a concomitant increase in reactive oxygen species (ROS) in these transgenic mice with disease progression. Importantly, RAC1, an essential component of the ROS-producing NADPH oxidase, is downstream of RAS, and we show that ROS production in NRAS/BCL2 mice is in part dependent on RAC1 activity. DNA damage and error-prone repair can be decreased or reversed in vivo by N-acetyl cysteine antioxidant treatment. Our data link gene abnormalities to constitutive DNA damage and increased DSB repair errors in vivo and provide a mechanism for an increase in the error rate of DNA repair with MDS disease progression. These data suggest treatment strategies that target RAS/RAC pathways and ROS production in human MDS/AML. [Cancer Res 2007;67(18):8762–71]

Supplementary Table 1 from Reactive Oxygen Species, DNA Damage, and Error-Prone Repair: A Model for Genomic Instability with Progression in Myeloid Leukemia?

Supplementary Table 2 from Reactive Oxygen Species, DNA Damage, and Error-Prone Repair: A Model for Genomic Instability with Progression in Myeloid Leukemia?

Supplementary Procedures, Figures 1-4 from BCL-2 and Mutant NRAS Interact Physically and Functionally in a Mouse Model of Progressive Myelodysplasia

Myelodysplastic syndromes (MDS) are clonal stem cell hematologic disorders that evolve to acute myeloid leukemia (AML) and thus model multistep leukemogenesis. Activating RAS mutations and overexpression of BCL-2 are prognostic features of MDS/AML transformation. Using NRASD12 and BCL-2, we created two distinct models of MDS and AML, where human (h)BCL-2 is conditionally or constitutively expressed. Our novel transplantable in vivo models show that expression of hBCL-2 in a primitive compartment by mouse mammary tumor virus–long terminal repeat results in a disease resembling human MDS, whereas the myeloid MRP8 promoter induces a disease with characteristics of human AML. Expanded leukemic stem cell (Lin−/Sca-1+/c-Kit+) populations and hBCL-2 in the increased RAS-GTP complex within the expanded Sca-1+ compartment are described in both MDS/AML–like diseases. Furthermore, the oncogenic compartmentalizations provide the proapoptotic versus antiapoptotic mechanisms, by activating extracellular signal-regulated kinase and AKT signaling, in determination of the neoplastic phenotype. When hBCL-2 is switched off with doxycycline in the MDS mice, partial reversal of the phenotype was observed with persistence of bone marrow blasts and tissue infiltration as RAS recruits endogenous mouse (m)BCL-2 to remain active, thus demonstrating the role of the complex in the disease. This represents the first in vivo progression model of MDS/AML dependent on the formation of a BCL-2:RAS-GTP complex. The colocalization of BCL-2 and RAS in the bone marrow of MDS/AML patients offers targeting either oncogene as a therapeutic strategy. [Cancer Res 2007;67(24):11657–67]

Supplementary Table 5 from Reactive Oxygen Species, DNA Damage, and Error-Prone Repair: A Model for Genomic Instability with Progression in Myeloid Leukemia?

Supplementary Figure 1 Legend from Reactive Oxygen Species, DNA Damage, and Error-Prone Repair: A Model for Genomic Instability with Progression in Myeloid Leukemia?

The role of ribosome biogenesis in erythroid development is supported by the recognition of erythroid defects in ribosomopathies in both Diamond-Blackfan anemia and 5q− syndrome. Whether ribosome biogenesis exerts a regulatory function on normal erythroid development is still unknown. In the present study, a detailed characterization of ribosome biogenesis dynamics during human and murine erythropoiesis showed that ribosome biogenesis is abruptly interrupted by the decline in ribosomal DNA transcription and the collapse of ribosomal protein neosynthesis. Its premature arrest by the RNA Pol I inhibitor CX-5461 targeted the proliferation of immature erythroblasts. p53 was activated spontaneously or in response to CX-5461, concomitant to ribosome biogenesis arrest, and drove a transcriptional program in which genes involved in cell cycle–arrested, negative regulation of apoptosis, and DNA damage response were upregulated. RNA Pol I transcriptional stress resulted in nucleolar disruption and activation of the ATR-CHK1-p53 pathway. Our results imply that the timing of ribosome biogenesis extinction and p53 activation is crucial for erythroid development. In ribosomopathies in which ribosome availability is altered by unbalanced production of ribosomal proteins, the threshold downregulation of ribosome biogenesis could be prematurely reached and, together with pathological p53 activation, prevents a normal expansion of erythroid progenitors.

During transformation, myelodysplastic syndromes (MDS) are characterized by reducing apoptosis of bone marrow (BM) precursors. Mouse models of high risk (HR)-MDS and acute myelogenous leukemia (AML) post-MDS using mutant NRAS and overexpression of human BCL-2, known to be poor prognostic indicators of the human diseases, were created. We have reported the efficacy of the BCL-2 inhibitor, ABT-737, on the AML post-MDS model, here, we report that this BCL-2 inhibitor also significantly extended survival of the HR-MDS mouse model, with reductions of BM blasts and lineage negative/Sca1+/KIT+ (LSK) cells. Secondary transplants showed increased survival in treated compared to untreated mice. Unlike the AML model, BCL-2 expression and RAS activity decreased following treatment and the RAS:BCL-2 complex remained in the plasma membrane. Exon-specific gene expression profiling (GEP) of HR-MDS mice showed 1952 differentially regulated genes upon treatment, including genes important for the regulation of stem cells, differentiation, proliferation, oxidative phosphorylation, mitochondrial function, and apoptosis, relevant in human disease. Spliceosome genes, found to be abnormal in MDS patients and downregulated in our HR-MDS model, such as Rsrc1 and Wbp4, were upregulated by the treatment, as were genes involved in epigenetic regulation, such as DNMT3A and B, upregulated upon disease progression and downregulated upon treatment.

Treating patients with diffuse large Bcell lymphoma (DLBCL) remains a challenge, with a remission rate of 75% at 2 years from diagnosis. The International Prognostic Index (IPI) [1] and molecularcharacterization [2] are employed in the stratification and relapse prediction. Additionally, 18F-fluorodeoxyglucose positron emission tomography (PET) and computed tomography (CT) have now become part of standard care in differentiating metabolic activity of the disease from fibrosisor necrosis [3]. Early optimism that the speed of response to treatment, as indicated by an interim-PET (iPET) scan after 2?3 cycles of chemotherapy, might reliably predict cure has not been fulfilled [4].To investigate the role of both an interim and an end-treatment-PET (ePET) scan for the management of DLBCL in an international setting, at a time when PET centers were becoming established globally, the International Atomic Energy Agency (IAEA) sponsored a study across 7 countries in Europe, South Asia, Southeast Asia, and South America [5]. This study, the largest study to date, found that 34% of cases were iPET+ after 2 or 3 cycles of standard chemotherapy (R-CHOP), but 54% of the iPET+ cases became ePET?; and that these ?slow responders? had relatively good outcomes at 2 years (event-free survival, EFS: 86%). Notably, the study found that by combining a negative iPET scan with 2 clinical components of the IPI (normal LDH and good performance status), it was possible to identify a population, 35% of all cases, 98% of whom were disease free 2 years after diagnosis. By contrast, iPET+ cases that remained PET+ at the end of treatment had dismal outcomes. These findings raisethe important question of how to separate slow-responding iPET+ cases who are PET? at the end treatment, who are destined for good survival, from those who will fail to achieve a complete or stable remission by continuing standard therapy. Fil: Omidvar, Nader. Cardiff University; Reino Unido Fil: Tekin, Nilgun. Ankara Üniversitesi; Turquía Fil: Conget, Paulette. Universidad del Desarrollo; Chile Fil: Bruna, Flavia Alejandra. Universidad del Desarrollo; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina Fil: Timar, Botond. Semmelweis Egyetem; Hungría Fil: Gagyi, Eva. Semmelweis Egyetem; Hungría Fil: Basak, Ranjan. Tata Memorial Hospital; India Fil: Auewarakul, Chirayu. Mahidol University; Tailandia Fil: Sritana, Narongrit. Mahidol University; Tailandia Fil: Cerci, Juliano Julio. Department of Nuclear Medicine, Quanta Diagnóstico e Terapia; Brasil Fil: DImamay, Mark Pierre. St Luke's Medical Centre; Filipinas Fil: Gyorke, Tamas. Semmelweis University; Hungría Fil: Redondo, Francisca. Fundación Arturo López Pérez; Chile Fil: Nair, Reena. Tata Memorial Hospital; India Fil: Gorospe, Charity. St Luke's Medical Centre; Filipinas Fil: Paez, DIana. International Atomic Energy Agency; Austria Fil: Fanti, Stefano. Universidad de Bologna; Italia Fil: Ozdag, Hilal. Ankara Üniversitesi; Turquía Fil: Padua, Rose Ann. Université Paris Diderot - Paris 7; Francia Fil: Carr, Robert. Guy’s and St. Thomas’ Hospital; Reino Unido

Higher-risk myelodysplastic syndrome (HR-MDS) has a poor prognosis in the absence of efficient therapy. The evaluation of new therapies in animal models of HR-MDS is hampered by the absence of accurate in vivo biomarkers of the disease. In this study we compared [18F]Fluoro-desoxyglucose Positron Emission Tomography (FDG-PET) and [18F]Fluoro-thymidine (FLT)-PET imaging for disease follow-up in a triple transgenic MMTVtTA/TetoBCL-2/MRP8NRASD12 mouse model of HR-MDS. Normal control FVB/N mice (G1,n=9) and HR-MDS mice (G2,n=12) underwent both FDG- and FLT-PET procedures at 2-day intervals, on a dedicated small animal device. Blood cell counting, BCL-2 and Mac-1hi/Gr-1lo expression measurements in blood were performed before each PET procedure. Visually, PET images of G2 mice demonstrated homogeneous FDG uptake in the whole skeleton similar to that observed in G1 mice, and abnormal FLT hot spots in bone marrow not observed in G1 mice. The intensity of FLT hot spots in bone marrow was higher in 3-months old G2 mice than in 2-months old G2 mice, concordant with a higher percentage of cells expressing Mac-1hi/Gr-1lo and lower platelets counts. We conclude that FLT-PET/CT imaging is a more valuable surrogate non-invasive quantitative marker of HR-MDS bone marrow involvement than FDG-PET/CT in our mouse model of HR-MDS.

Achaete-scute homolog 1 gene (ASCL1) is a gene classifier for the proneural (PN) transcriptional subgroup of glioblastoma (GBM) that has a relevant role in the neuronal-like differentiation of GBM cancer stem cells (CSCs) through the activation of a PN gene signature. Besides prototypical ASCL1 PN target genes, the molecular effectors mediating ASCL1 function in regulating GBM differentiation and, most relevantly, subgroup specification are currently unknown. Here we report that ASCL1 not only promotes the acquisition of a PN phenotype in CSCs by inducing a glial-to-neuronal lineage switch but also concomitantly represses mesenchymal (MES) features by directly downregulating the expression of N-Myc downstream-regulated gene 1 (NDRG1), which we propose as a novel gene classifier of MES GBMs. Increasing the expression of ASCL1 in PN CSCs results in suppression of self-renewal, promotion of differentiation and, most significantly, decrease in tumorigenesis, which is also reproduced by NDRG1 silencing. Conversely, both abrogation of ASCL1 expression in PN CSCs and enforcement of NDRG1 expression in either PN or MES CSCs induce proneural-to-mesenchymal transition (PMT) and enhanced mesenchymal features. Surprisingly, ASCL1 overexpression in MES CSCs increases malignant features and gives rise to a neuroendocrine-like secretory phenotype. Altogether, our results propose that the fine interplay between ASCL1 and its target NDRG1 might serve as potential subgroup-specific targetable vulnerability in GBM; enhancing ASCL1 expression in PN GBMs might reduce tumorigenesis, whereas repressing NDRG1 expression might be actionable to hamper the malignancy of GBM belonging to the MES subgroup.

We have previously shown that a specific promyelocytic leukemia-retinoic acid receptor alpha (PML-RARA) DNA vaccine combined with all-trans retinoic acid (ATRA) increases the number of long term survivors with enhanced immune responses in a mouse model of acute promyelocytic leukemia (APL). This study reports the efficacy of a non-specific DNA vaccine, pVAX14Flipper (pVAX14), in both APL and high risk myelodysplastic syndrome (HR-MDS) models. PVAX14 is comprised of novel immunogenic DNA sequences inserted into the pVAX1 therapeutic plasmid. APL mice treated with pVAX14 combined with ATRA had increased survival comparable to that obtained with a specific PML-RARA vaccine. Moreover, the survival advantage correlated with decreased PML-RARA transcript levels and increase in anti-RARA antibody production. In HR-MDS mice, pVAX14 significantly improved survival and reduced biomarkers of leukemic transformation such as phosphorylated mitogen-activated protein/extracellular signal-regulated kinase kinase (MEK) 1. In both preclinical models, pVAX14 vaccine significantly increased interferon gamma (IFNγ) production, memory T-cells (memT), reduced the number of colony forming units (CFU) and increased expression of the adapter molecule signalling to NF-κB, MyD88. These results demonstrate the adjuvant properties of pVAX14 providing thus new approaches to improve clinical outcome in two different models of myeloid malignancies, which may have potential for a broader applicability in other cancers.

Disease markers are defined as the biomarkers with specific characteristics during the general physical, pathological or therapeutic process, the detection of which can inform the progression of present biological process of organisms. However, the exploration of disease markers is complicated and difficult, and only a few markers can be used in clinical practice and there is no significant difference in the mortality of cancers before and after biomarker exploration. Translational medicine focuses on breaking the blockage between basic medicine and clinical practice. In addition, it also establishes an effective association between researchers engaged on basic scientific discovery and clinical physicians well informed of patients' requirements, and gives particular attentions on how to translate the basic molecular biological research to the most effective and appropriate methods for the diagnosis, treatment and prevention of diseases, hoping to translate basic research into the new therapeutic methods in clinic. Therefore, this study mainly summarized the exploration of disease markers under translational medicine model so as to provide a basis for the translation of basic research results into clinical application.

As a part of an international study on the molecular analysis of Diffuse Large B-cell Lymphoma (DLBCL), a robust protocol for gene expression analysis from RNA extraction to qRT-PCR using Formalin Fixed Paraffin Embedded tissues was developed. Here a study was conducted to define a strategy to validate the previously reported 6-gene (LMO2, BCL6, FN1, CCND2, SCYA3 and BCL2) model as predictor of prognosis in DLBCL. To avoid variation, all samples were tested in a single centre and single platform. This study comprised 8 countries (Brazil, Chile, Hungary, India, Philippines, S. Korea, Thailand and Turkey). Using the Kaplan-Meier and log rank test on patients (n=162) and two mortality risk groups (with those above and below the mean representing high and low risk groups) confirmed that the 6-gene predictor score correlates significantly with overall survival (OS, p < 0.01) but not with event free survival (EFS, p=0.18). Adding the International Prognostic Index (IPI) shows that the 6-gene predictor score correlates significantly with high IPI scores for OS (p < 0.05), whereas those with low IPI scores show a trend not reaching significance (p=0.08). This study defined an effective and economical qRT-PCR strategy and validated the 6-gene score as a predictor of OS in an international setting. Fil: Tekin, Nilgun. Ankara University. Biotechology Institute; Turquía Fil: Omidvar, Nader. Cardiff University; Reino Unido Fil: Morris, Tim Peter. Clinical Trials Unit at University College. Medical Research Council; Reino Unido Fil: Conget, Paulette. Universidad del Desarrollo; Chile Fil: Bruna, Flavia Alejandra. Universidad del Desarrollo; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina Fil: Timar, Botond. Semmelweis University. Department of Pathology and Experimental Cancer Research; Hungría Fil: Gagyi, Eva. Semmelweis University. Department of Pathology and Experimental Cancer Research; Hungría Fil: Basak, Ranjan. Tata Memorial Hospital. Departments of Medical Oncology & Pathology; India Fil: Naik, Omkar. Tata Memorial Hospital. Departments of Medical Oncology & Pathology; India Fil: Auewarakul, Chirayu. Faculty of Medicine Sirira; Tailandia. Chulabhorn Cancer Centre; Tailandia Fil: Sritana, Narongrit. Faculty of Medicine Sirira; Tailandia. Chulabhorn Cancer Centre; Tailandia Fil: Levy, Debora. Chulabhorn Cancer Centre; Tailandia. Faculty of Medicine Sirira; Tailandia Fil: Cerci, Juliano Julio. Department of Nuclear Medicine. Quanta - Diagnóstico e Terapia; Brasil Fil: Bydlowski, Sergio Paulo. Universidade de Sao Paulo; Brasil Fil: Pereira, Juliana. Universidade de Sao Paulo; Brasil Fil: Dimamay, Mark Pierre. St. Lukes Medical. Research and Biotechnology Division; Filipinas Fil: Natividad, Filipinas. St. Lukes Medical. Research and Biotechnology Division; Filipinas Fil: Chung, June-Key. Seoul National University Hospital. Department of Nuclear Medicine; Corea del Sur Fil: Belder, Nevin. Ankara University. Biotechology Institute; Turquía Fil: Kuzu, Isinsu. Ankara University. Faculty of Medicina; Turquía Fil: Paez, Diana. International Atomic Energy Agency; Austria Fil: Dondi, Maurizio. International Atomic Energy Agency; Austria Fil: Carr, Robert. King’s College. Guy’s & St Thomas’ Hospital; Reino Unido Fil: Ozdag, Hilal. Ankara University. Faculty of Medicina; Turquía Fil: Padua, Rose Ann. Institut National de la Sante Et de la Recherche Médica; Francia. Université Paris-Diderot; Francia. Institut Universitaire d'Hématologie; Francia

Introduction: Targeted drugs are needed for HR-MDS/AML, particularly in elderly patients and Venetoclax, approved for some CLL, gives promising results in elderly AML. Assays to predict response to treatment may enable us to deliver personalized treatment. We sought to determine the most informative assay to predict response; viability assays can directly measure the effects of reagents on growth. Progenitor assays can potentially determine if the reagents can target diseased primitive cells. PET scanning can be used to follow response to treatment. Methods: Peripheral blood (PB) or bone marrow (BM) from 7 MDS/AML patients were incubated in a) no treatment, b) ABT-199 (1 µM) (Abbvie), c) GDC-0973 (1 µM) (Genentech) or d) ABT-199+GDC-0973 (1 µM of each) and assessed for viability using the MTT assay (n=2); cell death followed using the Incucyte® Zoom System (Essen Bioscience) (n=2) or methocult progenitor assays (Stem Cell Technologies) (n=4). Having shown that RAS:BCL-2 co-localization correlated with prognosis in MDS/AML patients (Leuk Res 37:312-9, 2013), immunofluorescence was undertaken. A micro PET device dedicated to mice was used to measure BM blast proliferation. After injection of 18F-FLT(a thymidine analogue) in mice untreated (n=7) or ABT-199 (75mg/kg)+GDC-0973(10mg/kg) treated (n=5) normal FVB/N, HR-MDS mice treated with vehicle (n=4), 2-month old HR-MDS before (n=5) and 3-month old before (n=4) and after ABT-199 (75mg/kg)+GDC-0973(10mg/kg) treatment (n=8), PET imaging was performed (Inveon Siemens Medical Systems), analyzed for signal and quantified. Results: Patient details and results are summarized on Table 1. Using the MTT assay 2 PB patient samples were found to be sensitive to ABT-199 treatment (Figure 1A, AS, p=0.00042 and YA, 0.00002) and more sensitive to the combination compared to untreated (AS, p=0.00007 and YA, 0.000003). With the incucyte the BM of one patient (AE) was found to be resistant to both ABT-199 and GDC-0973, but sensitive to the combination (Figure 1B). PB and BM from patient JA were assayed for apoptosis with the incucyte and were found to be sensitive to ABT-199 with increased apoptosis, resistant to GDC-0973 with decreased apoptosis and sensitive to the combination. Four bone marrow samples were tested in the 4 conditions using the progenitor assay (Figure 1C). Three patients were sensitive to GDC-0973, inhibiting any colony formation and the fourth had reduced colony numbers. In this assay patient JA appeared to be sensitive to GDC-0973 treatment whereas the incucyte assay scored this sample to be resistant to apoptosis; thus the cytotoxic effects of GDC-0973 may not be via apoptopsis. As the progenitor assay is likely to score the primitive disease population, this assay may prove more informative than the others without prior selection. One patient (DH) was clearly resistant to ABT-199, whereas the other three (JA, CB and FL) had reduced colony growth. All patients were sensitive to the combination treatment and inhibited colony growth. The RAS:BCL-2 co-localization in the PB revealed no complex in either the Mito or PM upon treatment with ABT-199 alone and some localization in the Mito with GDC-0973. With both ABT-199 and GDC-0973, there were hardly any cells confirming the cytotoxic effects of the combination. As we have previously shown that PM co-localization of the complex is associated with drug resistance (Blood 130:2613, 2017Suppl), we used the combination on our HR-MDS mouse model, where the complex co-localizes in the PM and followed the mice by PET scanning (Figure 1D). Weak signal was visualized in the femurs of untreated and ABT-199+GDC-0973 treated FVB/N mice (FBR 1.17+/-0.34 and 1.02+/-0.08 respectively). Mild PET signal was seen in the femurs of 2 month-old HR-MDS mice, (FBR 1.79+/-0.98). Intense PET signal was seen in the femurs and proximal humerus of HR-MDS mice treated with vehicle (3 month-old, FBR=2.35+/-1.32). Low PET signals were seen in the femurs of 5/8 HR-MDS mice treated with ABT-199+GDC-0973 (FBR=1.93+/-0.84). FBRs of the 3 groups of HR-MDS mice were significantly higher than those of FBV/N groups. Conclusion: Combined Venetoclax (ABT-199) and GDC-0973 targets MDS/AML progenitors and can potentially overcome drug resistance with the disruption of the RAS:BCL-2 complex. Bone marrow disease progression in HR-MDS mice can be monitored with 18F-FLT-PET imaging; PET data shows that the combination slows down disease progression. Disclosures Padua: Abbvie: Research Funding; Genentech: Research Funding. Giraudier:Novartis: Research Funding. Konopleva:Stemline Therapeutics: Research Funding. Andreeff:Oncoceutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; United Therapeutics: Patents & Royalties: GD2 inhibition in breast cancer ; Reata: Equity Ownership; Celgene: Consultancy; Jazz Pharma: Consultancy; Oncolyze: Equity Ownership; Amgen: Consultancy, Research Funding; Eutropics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Aptose: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Daiichi-Sankyo: Consultancy, Patents & Royalties: MDM2 inhibitor activity patent, Research Funding; SentiBio: Equity Ownership; Astra Zeneca: Research Funding.

The International Atomic Energy Agency sponsored a large, multinational, prospective study to further define PET for risk stratification of diffuse large B-cell lymphoma and to test the hypothesis that international biological diversity or diversity of healthcare systems may influence the kinetics of treatment response as assessed by interim PET (I-PET).Cancer centers in Brazil, Chile, Hungary, India, Italy, the Philippines, South Korea, and Thailand followed a common protocol based on treatment with R-CHOP (cyclophosphamide, hydroxyadriamycin, vincristine, prednisolone with rituximab), with I-PET after 2-3 cycles of chemotherapy and at the end of chemotherapy scored visually.Two-year survivals for all 327 patients (median follow-up, 35 mo) were 79\% (95\% confidence interval [CI], 74\%-83\%) for event-free survival (EFS) and 86\% (95\% CI, 81\%-89\%) for overall survival (OS). Two hundred ten patients (64\%) were I-PET-negative, and 117 (36\%) were I-PET-positive. Two-year EFS was 90\% (95\% CI, 85\%-93\%) for I-PET-negative and 58\% (95\% CI, 48\%-66\%) for I-PET-positive, with a hazard ratio of 5.31 (95\% CI, 3.29-8.56). Two-year OS was 93\% (95\% CI, 88\%-96\%) for I-PET-negative and 72\% (95\% CI, 63\%-80\%) for I-PET-positive, with a hazard ratio of 3.86 (95\% CI, 2.12-7.03). On sequential monitoring, 192 of 312 (62\%) patients had complete response at both I-PET and end-of-chemotherapy PET, with an EFS of 97\% (95\% CI, 92\%-98\%); 110 of these with favorable clinical indicators had an EFS of 98\% (95\% CI, 92\%-100\%). In contrast, the 107 I-PET-positive cases segregated into 2 groups: 58 (54\%) achieved PET-negative complete remission at the end of chemotherapy (EFS, 86\%; 95\% CI, 73\%-93\%); 46\% remained PET-positive (EFS, 35\%; 95\% CI, 22\%-48\%). Heterogeneity analysis found no significant difference between countries for outcomes stratified by I-PET.This large international cohort delivers 3 novel findings: treatment response assessed by I-PET is comparable across disparate healthcare systems, secondly a negative I-PET findings together with good clinical status identifies a group with an EFS of 98\%, and thirdly a single I-PET scan does not differentiate chemoresistant lymphoma from complete response and cannot be used to guide risk-adapted therapy.

Using an acute promyelocytic leukemia (APL) preclinical model, we show that oncogene-specific PCR (Polymerase Chain Reaction)-based assays allow to evaluate the efficacy of immunotherapy combining all-trans retinoic acid (ATRA) and a DNA-based vaccine targeting the promyelocytic leukemia-retinoic acid receptor alpha (PML-RARα) oncogene. Kaplan-Meier survival analysis according to the peripheral blood PML-RARα normalized copy number (NCN) clearly shows that ATRA + DNA-treated mice with an NCN lower than 10 (43%) formed the group with a highly significant (p 0.0001) survival advantage. Furthermore, a PCR assay was used to assess various tissues and organs for the presence of PML-RARα-positive cells in long-term survivors (n = 15). As expected, the majority of mice (n = 10) had no measurable tissue level of PML-RARα. However, five mice showed a weak positive signal in both the brain and spleen (n = 2), in the brain only (n = 2) and in the spleen only (n = 1). Thus tracking the oncogene-positive cells in long-term survivors reveals for the first time that extramedullary PML-RARα-positive cell reservoirs such as the brain may persist and be involved in relapses.

Addressing the global burden of cancer, understanding its diverse biology, and promoting appropriate prevention and treatment strategies around the world has become a priority for the United Nations and International Atomic Energy Agency (IAEA), the WHO, and International Agency for Research on Cancer (IARC). The IAEA sponsored an international prospective cohort study to better understand biology, treatment response, and outcomes of diffuse large B-cell lymphoma (DLBCL) in low and middle-income countries across five UN-defined geographical regions. We report an analysis of biological variation in DLBCL across seven ethnic and environmentally diverse populations. In this cohort of 136 patients treated to a common protocol, we demonstrate significant biological differences between countries, characterized by a validated prognostic gene expression score (p

Arsenic trioxide (ATO) mediates PML-RARA (promyelocytic leukemia–retinoic acid receptor-α) oncoprotein degradation via the proteasome pathway and this degradation appears to be critical for achieving cure in acute promyeloytic leukemia (APL). We have previously demonstrated significant micro-environment-mediated drug resistance (EMDR) to ATO in APL. Here we demonstrate that this EMDR could be effectively overcome by combining a proteasome inhibitor (bortezomib) with ATO. A synergistic effect on combining these two agents in vitro was noted in both ATO-sensitive and ATO-resistant APL cell lines. The mechanism of this synergy involved downregulation of the nuclear factor-κB pathway, increase in unfolded protein response (UPR) and an increase in reactive oxygen species generation in the malignant cell. We also noted that PML-RARA oncoprotein is effectively cleared with this combination in spite of proteasome inhibition by bortezomib, and that this clearance is mediated through a p62-dependent autophagy pathway. We further demonstrated that proteasome inhibition along with ATO had an additive effect in inducing autophagy. The beneficial effect of this combination was further validated in an animal model and in an on-going clinical trial. This study raises the potential of a non-myelotoxic proteasome inhibitor replacing anthracyclines in the management of high-risk and relapsed APL.

pVAX14DNA-mediated add-on immunotherapy combined with arsenic trioxide and all- trans retinoic acid targeted therapy effectively increases the survival of acute promyelocytic leukemia mice

Objective Primary polycythemia in dogs is classified as a myeloproliferative syndrome with a chronic progressive course and unspecific symptoms. Diagnosis is based on exclusion criteria. In humans, the presence of an acquired recurrent mutation within the JAK2 gene has recently been identified in 90% of the patients with polycythemia vera. This mutation (V617F) is located in the pseudokinase domain of JAK2, leading to constitutive activation of the kinase responsible for the polycythemia. Detection of the mutation has now become a major diagnostic tool in humans for polycythemia vera diagnosis. As the canine JAK2 gene shares strong homology with its human counterpart, we looked for the presence of JAK2 mutations in dogs with an elevated hematocrit. Materials and Methods Direct sequencing of the JAK2 exon 14 was performed on DNA extracted from the peripheral blood of five dogs suspected of primary polycythemia. Mutant subclones were expressed in interleukin-3−dependent BaF3 cells and tested for cytokine independency. Results One dog presented with a three-base change in codons 617 and 618 of JAK2 giving rise to V617F and C618L mutations. By polymerase chain reaction product subcloning, we demonstrated the coexistence of the wild-type sequence and a triple mutant sequence, while DNA from buccal swab contained the wild-type sequence only. Transfection of BaF3 cells with the triple mutant cDNA, but not with the wild-type complementary DNA, resulted in cytokine-independent growth and constitutive signal transducer and activation of transcription 5 phosphorylation. Conclusions Identical mutations of the JAK2 gene occur in humans and dogs, giving rise to a constitutively active JAK2 kinase, suggesting a common mechanism for human and canine diseases. Thus, common diagnostic tools and therapeutic approaches may be relevant.

Rational drug discovery relies on pathognomonic molecular reporters of disease or biomarkers. Therefore biomarkers contain relational or contextual information about disease pathophysiology. Two broad pathways can be taken to identify biomarkers: a 'top-down', holistic approach that makes no assumptions about biomarker type, or the 'bottom-up' approach, which is hypothesis driven and relies on a priori information. Both approaches involve parallel or sequential methods that include genomic and proteomic profiling. Biomarker discovery and translational medicine owe much to isotopic techniques because these provide near-real-time information about disease status as diagnostics, in drug delivery and for monitoring treatment. Here, we provide an overview of recent developments and some insight into the future role of isotopes in biomarker discovery and disease therapy.

Myelodysplastic syndromes (MDS) are clonal stem cell hematologic disorders that evolve to acute myeloid leukemia (AML) and thus model multistep leukemogenesis. Activating RAS mutations and overexpression of BCL-2 are prognostic features of MDS/AML transformation. Using NRASD12 and BCL-2, we created two distinct models of MDS and AML, where human (h)BCL-2 is conditionally or constitutively expressed. Our novel transplantable in vivo models show that expression of hBCL-2 in a primitive compartment by mouse mammary tumor virus–long terminal repeat results in a disease resembling human MDS, whereas the myeloid MRP8 promoter induces a disease with characteristics of human AML. Expanded leukemic stem cell (Lin−/Sca-1+/c-Kit+) populations and hBCL-2 in the increased RAS-GTP complex within the expanded Sca-1+ compartment are described in both MDS/AML–like diseases. Furthermore, the oncogenic compartmentalizations provide the proapoptotic versus antiapoptotic mechanisms, by activating extracellular signal-regulated kinase and AKT signaling, in determination of the neoplastic phenotype. When hBCL-2 is switched off with doxycycline in the MDS mice, partial reversal of the phenotype was observed with persistence of bone marrow blasts and tissue infiltration as RAS recruits endogenous mouse (m)BCL-2 to remain active, thus demonstrating the role of the complex in the disease. This represents the first in vivo progression model of MDS/AML dependent on the formation of a BCL-2:RAS-GTP complex. The colocalization of BCL-2 and RAS in the bone marrow of MDS/AML patients offers targeting either oncogene as a therapeutic strategy. [Cancer Res 2007;67(24):11657–67]

Targeted therapies for hematological malignancies have come of age since the advent of all trans retinoic acid (ATRA) for treating APL and STI571/Imatinib Mesylate/Gleevec for CML. There are good molecular targets for other malignancies and several new drugs are in clinical trials. In this review, we will concentrate on individual abnormalities that exist in the myelodysplastic syndromes (MDS) and myeloid leukemias that are targets for small molecule therapies (summarised in Fig. 1). We will cover fusion proteins that are produced as a result of translocations, including BCR-ABL, the FLT3 tyrosine kinase receptor and RAS. Progression of diseases such as MDS to secondary AML occur as a result of changes in the balance between cell proliferation and apoptosis and we will review targets in both these areas, including reversal of epigenetic silencing of genes such as p15(INK4B).

Despite improved molecular characterization of malignancies and development of targeted therapies, acute leukemia is not curable and few patients survive more than 10 years after diagnosis. Recently, combinations of different therapeutic strategies (based on mechanisms of apoptosis, differentiation and cytotoxicity) have significantly increased survival. To further improve outcome, we studied the potential efficacy of boosting the patient's immune response using specific immunotherapy. In an animal model of acute promyelocytic leukemia, we developed a DNA-based vaccine by fusing the human promyelocytic leukemia-retinoic acid receptor-alpha (PML-RARA) oncogene to tetanus fragment C (FrC) sequences. We show for the first time that a DNA vaccine specifically targeted to an oncoprotein can have a pronounced effect on survival, both alone and when combined with all-trans retinoic acid (ATRA). The survival advantage is concomitant with time-dependent antibody production and an increase in interferon-gamma (IFN-gamma). We also show that ATRA therapy on its own triggers an immune response in this model. When DNA vaccination and conventional ATRA therapy are combined, they induce protective immune responses against leukemia progression in mice and may provide a new approach to improve clinical outcome in human leukemia.

The retinoic acid receptor alpha (RARalpha) plays a central role in the biology of the myeloid cellular compartment. Chromosomal translocations involving the RARalpha locus probably represent the malignant initiating events in acute promyelocytic leukemia (APL). Recent studies that identify novel interactions between RARalpha and the nuclear receptor co-activators and co-repressors, new functions of the oncogenic RARalpha fusion proteins and their catabolism in retinoic acid-induced differentiation, and the availability of new transgenic mice models have provided important insights into our understanding of the mechanisms by which mutant forms of RARalpha can be implicated in the development of leukemia. Novel alterations of the RARalpha gene identified in hematopoietic malignant disorders other than APL, such as myelodysplastic syndromes, non-APL acute myeloid leukemias and B-chronic lymphocytic leukemias, suggest that disruption of the RARalpha gene might predispose to myeloid and lymphoid disorders.

The retinoic acid receptor alpha (RAR alpha) protein plays a central role in myeloid differentiation, and chromosomal translocations disrupting the RAR alpha gene are implicated in the development of acute myeloid leukaemia (AML). To identify haemopoietic malignant disorders which may also be linked to RAR alpha abnormalities, Southern blot analysis was performed in DNA from 153 patients with haematological malignancies other than AML FAB type M3 using RAR alpha cDNA probes. Alterations of RAR alpha were detected in 1/42 myelodysplastic syndromes (MDS), 2/24 AML, 3/47 B-chronic lymphocytic leukaemias (B-CLL), 0/40 lymphomas and 0/60 normal individuals. These data strongly suggest that alterations of RAR alpha might predispose for myeloid and lymphoid disorders.

Two flow cytometric apoptosis assays, the terminal deoxynucleotidyl transferase (TdT) assay and in situ nick translation (ISNT) assay, were assessed for their ability to quantitate drug-induced apoptosis in CLL lymphocytes. In contrast to HL60 cells, biotinylated dUTP could not be effectively incorporated into apoptotic CLL lymphocytes using exogenous TdT. This suggested that CLL lymphocytes possess a different type of endonuclease that cleaves DNA, leaving blunt or 3′ recessed DNA breaks, which are poor substrates for TdT. This possibility was tested using λ exonuclease, which can convert a blunt or 3′ recessed DNA break into a 3′ overhang. Apoptotic CLL lymphocytes pre-treated with λ exonuclease demonstrated increased nucleotide incorporation with TdT. Single-strand DNA breaks are also present in apoptotic CLL lymphocytes, as labelled nucleotides could be incorporated using the in situ nick translation assay. This study suggests that the efficiency of tailing reactions may be limited by the nature of the endonuclease activity in certain cell types and that validation with other parameters is an essential prerequisite to their quantitative use. Cytometry 31:130–136, 1998. © 1998 Wiley-Liss, Inc.

In an acute promyelocytic leukemia (APL)-transplantable mouse model, we previously reported the presence of antibodies recognizing PML-RARalpha and RARalpha in the sera of ATRA-treated mice. To evaluate this immune response, we determined the prevalence of anti-RARalpha antibodies in a cohort of 48 APL mice, treated by ATRA (n = 24) or by placebo pellets (n = 24), and in a preliminary subset of 9 patients with APL using a specific enzyme-linked immunosorbent assay (ELISA). In APL mice, significantly higher antibody levels were observed at the latest time points (day 48 to 58 levels superior to day 15 to 18 or day 28 to 38 levels). Antibody levels were higher in ATRA-treated mice than in placebo-treated mice and were also predictive of better survival. In the patients with APL, anti-RARalpha antibodies were detected at diagnosis and after maintenance therapy, reminiscent of the ATRA-treated APL mice. Antinuclear or antineutrophil cytoplasmic autoantibodies were also detected. These data reveal for the first time that in patients with APL an immune response may be detected at diagnosis and enhanced after maintenance therapy.

RAS mutations arise at high frequency (20–40%) in both acute myeloid leukemia and myelodysplastic syndrome (which is considered to be a manifestation of preleukemic disease). In each case, mutations arise predominantly at the N-RAS locus. These observations suggest a fundamental role for this oncogene in leukemogenesis. However, despite its obvious significance, little is known of how this key oncogene may subvert the process of hematopoiesis in human cells. Using CD34+ progenitor cells, we have modeled the preleukemic state by infecting these cells with amphotropic retrovirus expressing mutant N-RAS together with the selectable marker gene lacZ. Expression of the lacZ gene product, β-galactosidase, allows direct identification and study of N-RAS–expressing cells by incubating infected cultures with a fluorogenic substrate for β-galactosidase, which gives rise to a fluorescent signal within the infected cells. By using multiparameter flow cytometry, we have studied the ability of CD34+ cells expressing mutant N-RAS to undergo erythroid differentiation induced by erythropoietin. By this means, we have found that erythroid progenitor cells expressing mutant N-RAS exhibit a proliferative defect resulting in an increased cell doubling time and a decrease in the proportion of cells in S + G2M phase of the cell cycle. This is linked to a slowing in the rate of differentiation as determined by comparative cell-surface marker analysis and ultimate failure of the differentiation program at the late-erythroblast stage of development. The dyserythropoiesis was also linked to an increased tendency of the RAS-expressing cells to undergo programmed cell death during their differentiation program. This erythroid lineage dysplasia recapitulates one of the most common features of myelodysplastic syndrome, and for the first time provides a causative link between mutational activation of N-RAS and the pathogenesis of preleukemia.

Point mutations at codons 301 and 969 of the FMS proto-oncogene have been reported in both myelodysplasia (MDS) and acute myeloid leukaemia (AML). We report here the incidence of such mutations in patients at risk of developing secondary MDS and AML. Peripheral blood DNA from 70 patients in remission from lymphoma was screened for mutations by oligonucleotide (ONH) using mutant specific probes. Codon 969 mutations were detected in 11 of the 70 (15.7%) cases. No codon 301 mutations were detected. Five of these mutations were confirmed using an independent technique (single nucleotide primer extension analysis, SNPE) and a further mutation was detected in a single patient using single-stranded conformational polymorphism analysis (SSCP). No codon 969 mutations were detected in 62 lymphoma biopsy specimens from these patients or from three patients with detectable FMS mutations where pre-therapy marrow was investigated by ONH. No mutations at either codons 301 or 969 were detected by ONH in 61 normal controls. Somatic mutations at codon 969 of the FMS gene occur commonly following cytotoxic therapy for lymphoma and their detection indicates the presence of a clonally expanded population of abnormal cells.

Objectifs Le syndrome myelodysplasique de haut risque (SMD-HR), caracterise par une diminution de l’apoptose des precurseurs de la moelle osseuse, est a risque de transformation en leucemie aigue myeloide (LAM) et de mauvais pronostic en l’absence de chimiotherapie efficace. L’evaluation de nouveaux traitements dans les modeles animaux est entravee par l’absence de biomarqueur fiable permettant de suivre in vivo l’efficacite therapeutique, la biopsie medullaire etant impossible chez la souris. La TEP-FLT permet de quantifier in vivo la proliferation cellulaire et a ete suggeree comme outil de diagnostic et de suivi therapeutique chez les patients atteints de LAM. Notre objectif etait d’evaluer la TEP-FLT pour la quantification in vivo des blastes medullaires chez la souris. Materiels et methodes Nous avons etudie 3 groupes de souris FVB/N : controles normales ( n = 4), souris porteuses du gene mute NRASD12 sous regulation du promoteur myeloide MRP8 ( n = 6) et modele transgenique MMTVtTA/TetoBCL-2/MRP8NRASD12 de SMD-HR ( n = 7). Toutes les souris ont une TEP/TDM a la FLT entre 10 et 19 semaines de vie. Des images statiques (10 mns) ont ete acquises 1 h apres injection du radiotraceur. Le % de dose de FLT injectee par g de moelle osseuse (%ID FLT/g) a ete quantifie sur les images au niveau des vertebres dorsales et des epiphyses femorales. Juste avant la TEP, des prelevements sanguins ont ete effectues pour la numeration des plaquettes sanguines et la mesure de l’expression du transgene BCl-2. Apres l’imagerie, la moelle osseuse des femurs a ete recueillie pour analyse cytologique. Resultats Les chiffres de plaquettes sanguines etait de 1496 ± 688/mL et 966 ± 226/mL (NS) chez, respectivement, les souris controles et les souris transgeniques ; l’expression de BCl-2 etait de 1,2 ± 1,1 % vs 24,3 ± 15,1 % ( p p p r = 0,43, NS), ni a l’expression de BCl-2 ( r = 0,35, NS). Par contre, ils etaient correles au %ID/g de FLT dans la moelle osseuse des vertebres dorsales ( r = 0,85 ; p r = 0,73 ; p r = 0,82 ; p = 0,0001). Conclusions La TEP-FLT est correlee au taux blastes medullaires dans notre modele murin de SMD-HR. Par contre, le taux de plaquettes sanguines et l’expression de BCl-2 n’apparaissent pas correles a l’infiltration blastique de la moelle osseuse. La TEP-FLT pourrait permettre le diagnostic de transformation des SMD-HR et eviter les biopsies de moelle osseuse repetees au cours du suivi therapeutique.

Myelodysplastic syndromes represent particularly challenging hematologic malignancies that arise from a large spectrum of genetic events resulting in a disease characterized by a range of different presentations and outcomes. Despite efforts to classify and identify the key genetic events, little improvement has been made in therapies that will increase patient survival. Animal models represent powerful tools to model and study human diseases and are useful pre-clinical platforms. In addition to enforced expression of candidate oncogenes, gene inactivation has allowed the consequences of the genetic effects of human myelodysplastic syndrome to be studied in mice. This review aims to examine the animal models expressing myelodysplastic syndrome-associated genes that are currently available and to highlight the most appropriate model to phenocopy myelodysplastic syndrome disease and its risk of transformation to acute myelogenous leukemia.