Kooperativer Bibliotheksverbund

In: Blood, American Society of Hematology, Vol. 122, No. 21 ( 2013-11-15), p. 842-842

Kurzfassung: Hepatosplenic T-cell lymphoma (HSTL) is a rare form of lymphoma, comprising less than 1% of the cases. However, HSTL extracts a highly disproportionate toll on patients with a median age of diagnosis of 35 years and an expected median survival of less than two years. The vast majority of HSTL patients eventually succumb to their disease. The genetic basis of the disease is largely unknown. Although abnormalities of chromosome 7, including isochromosome 7q occur commonly in the disease, the role of specific genes and genetic mutations to the disease remains essentially unknown. Methods In this study, we sought to define the genetic features of HSTL through the whole genome sequencing and exome sequencing of 32 HSTL tumors and germline DNA (where available) from the same patients. Exome enrichment of DNA was carried out using the Agilent solution-based system of exon capture, which uses RNA baits to target all protein coding genes as well as ∼700 human microRNAs. Both whole genome and exome sequencing were performed using the Illumina platform. Results We identified 28 candidate cancer genes that were recurrently mutated in HSTL. Commonly implicated biological processes comprising these genes included signal transduction (e.g. PIK3CD, KRAS) and chromatin modification (e.g. TET1, SETD2 and MLL3), accounting for 16% and 23% of the total genetic events, respectively. Nearly all of these genes have been implicated in HSTL for the first time and provide new insights into the pathogenesis of the disease and potential targets for therapy. Whole genome sequencing confirmed isochromosome 7q as the most common recurrent chromosomal abnormality in HSTL and additional structural genetic alterations in chromosome 7. Conclusion Our study provides the most comprehensive genetic portrait of HSTL to date, and is a significant step in defining the genetic causes of this disease. Disclosures: No relevant conflicts of interest to declare.

Materialart: Online-Ressource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood.V122.21.842.842

Sprache: Englisch

Verlag: American Society of Hematology

Publikationsdatum: 2013

ZDB Id: 1468538-3

ZDB Id: 80069-7

In: Blood, American Society of Hematology, Vol. 106, No. 11 ( 2005-11-16), p. 415-415

Kurzfassung: Background Burkitt lymphoma(BL) is a potentially curable, aggressive lymphoma. The distinction between BL and diffuse large B-cell lymphoma (DLBCL) is important because they differ significantly in clinical management. The distinction can be difficult because DLBCL can resemble BL in morphology, immunophenotype and cytogenetics. We investigated whether gene expression profiling (GEP) could create a molecular definition of BL that can reliably distinguish it from DLBCL. Methods Biopsy samples were collected from 312 patients with a diagnosis of sporadic BL or Burkitt-like lymphoma, or DLBCL. All cases were reviewed by a panel of expert hematopathologists. GEP of all the samples was carried out using a specialized oligonucleotide microarray. We constructed a predictor using 197 genes to distinguish BL from each molecular subtype of DLBCL. Leave-one-out cross-validation was used to evaluate the predictor’s performance. Chemotherapy treatments were grouped into either CHOP-like(CHOP, CNOP) or intensive(BFM, CODOX-M IVAC, regimens requiring stem cell rescue). Results After pathology review, the samples were reclassified as:classic BL(25 cases), atypical BL(19), DLBCL(261), and unclassifiable lymphoma(7). All classic BL and 18/19 cases of atypical BL shared a profile that was strikingly different from that of all the molecular subtypes of DLBCL, including those DLBCL cases that have a c-myc translocation. C-myc and its target genes, and genes related to germinal center differentiation were expressed at high levels in BL. NF-kB and its target genes and MHC class-I genes were expressed at very low levels in BL. Interestingly, 10 cases that were DLBCL by pathology were classified as BL by the predictor. The diagnosis of BL was supported by FISH analysis indicating a c-myc translocation. Among adults identified as having BL by the predictor (with full clinical data in N=15), overall survival was markedly superior for those receiving intensive regimens compared to CHOP-like regimens(Fig 1). The groups were similar with regard to age, stage, performance status and sites of involvement. Conclusion This study demonstrates that the molecular characteristics of BL can be used to accurately distinguish it from DLBCL. Importantly, a subgroup of BL was identified by the predictor that could not be diagnosed as BL by conventional criteria. The ability of the predictor to identify patients who benefit from aggressive therapies suggests that it will be useful in the diagnosis and management of patients with Burkitt lymphoma. Figure Figure

Materialart: Online-Ressource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood.V106.11.415.415

Sprache: Englisch

Verlag: American Society of Hematology

Publikationsdatum: 2005

ZDB Id: 1468538-3

ZDB Id: 80069-7

In: Blood, American Society of Hematology, Vol. 120, No. 21 ( 2012-11-16), p. 471-471

Kurzfassung: Abstract 471 Lymphoma progression remains an obstacle after allogeneic HCT, particularly after non-myeloablative conditioning in patients with high-risk histology (non-indolent; Kahl et al; Blood, 2007) and chemotherapy refractory disease (Bishop et al; Cancer, 2010). In murine models, rapamycin-resistant T cells favorably modulated the balance between GVHD, graft rejection, and GVT effects. To translate this, we conducted a multi-center phase II trial (NCT0074490) of T-Rapa cells infused as a pre-emptive DLI after low-intensity allogeneic HCT; here, we report overall outcome of patients with high-risk lymphoma diagnoses, many of whom were chemotherapy refractory. T-Rapa cells were manufactured by ex vivo culture of donor CD4+ T cells using CD3/CD28 co-stimulation and IL-4, IL-2, and rapamycin for 12-days (T-Rapa12) or 6-days (T-Rapa6), and administered (2.5 × 107 cells/kg) at d14 post-HCT. Both populations of T-Rapa cells expressed a mixed Th2/Th1 phenotype with minimal T-Reg content. Patients (n=42) received outpatient-intensity chemotherapy (typically, EPOCH-FR) until CD4 count was 〈 200 cells/μl, and then received an HLA-matched sibling mobilized allograft and GVHD prophylaxis of cyclosporine plus short-course sirolimus (to d14 post-HCT); conditioning consisted of fludarabine (120 mg/m2) and cyclophosphamide (1200 mg/m2). Table I details the high-risk diagnoses, pre-treatment history (median of 4 prior regimens), remission status at time of HCT (7/42 [17%] in CR), and presence of chemotherapy refractory disease (stable or progressive disease to prior therapy: 23/42 pts, 55%). T-Rapa cell infusion was relatively safe, with no engraftment syndrome or d100 TRM; incidences of grade II-IV acute, late acute, and classical chronic GVHD were 17%, 34%, and 36%, respectively. Initial mixed donor/host chimerism converted to predominate donor chimerism after T-Rapa cell DLI (Table I). Overall median survival probability at 24 months post-HCT is 85.7% for patients with chemotherapy sensitive disease vs. 39.1% for patients with chemotherapy refractory disease (Fig. 1; p=0.0008). All deaths were due to progressive disease except for 2 infection-related deaths at days 162 and 359 post-HCT; all surviving patients are in CR. Survival was not statistically significantly influenced by DLI type (T-Rapa12 vs. T-Rapa6) or histology-type (NHL vs. HD). Pre-emptive DLI using donor T-Rapa cells after low-intensity conditioning is safe and very effective in patients with high-risk lymphoma diagnoses and chemotherapy sensitive disease; for such patients, future randomized trials should compare low-intensity T-Rapa cell therapy to other transplantation regimens. For patients with high-risk lymphoma diagnoses and chemotherapy-refractory disease, we are evaluating a modification to the current platform that incorporates high-dose sirolimus therapy. Table I Patient Characteristics Chimerism Resultsc CD3 CD15 Number of Patients n = 42 Day 14 post-HCT 57 (12-97) 46 (8-94) Age (median, range) 44 (23-68) Day 28 post-HCT 77 (37-100) 76 (29-98) Sex (male/female) (26/16) # of Prior Therapies (mean, range) 4 (1-6) Day 100 post-HCT 89 (51-100) 93 (35-100) Histologya n=26 total (62%) Survival Resultsd 24 Mo. Surv. Prob. NHL Category n=12 ChemoSens/T-R12 78.6% (n=7) DLBCL n=5 ChemoSens/T-R6 85.7% (n=12) DLBCL-tr n=2 ChemoRefr/T-R12 41.7% (n=11) DLBCL-EBV n=3 ChemoRefr/T-R6 36.4% (n=12) PlasmacytoidDC n=3 All NHL 57.4% (n=26) T Cell n=16 total (38%) All HD/Grey Zone 68.8% (n=16) HD Category n=12 HD n=4 Grey Zone Chemo. Responseb 23/42 (55%) Refractory (SD/PD) 19/42 (45%) Sensitive (PR/CR) Complete Remission 7/42 (17%) At Time of HCT DLBCL, diffuse large B cell lymphoma; DLBCL-tr, transformed; DLBCL-EBV, Epstein Barr Virus related; Plasmacytoid DC, dendritic cell; HD, Hodgkins Disease; SD, stable disease; PD, progressive disease; PR/CR is partial or complete response. a Grey Zone Lymphoma and Hodgkins Disease were pooled for statistical analyses. b Chemotherapyresponse, as determined after last regimen prior to study entry. c Chimerism determined by VNTR-PCR at days 14, 28, and 100 post-HCT (mean and range of values shown); CD3, T cell chimerism; CD15, myeloid cell chimerism. d Survival by Kaplan-Meier analysis; 24 month median survival probability values shown; T-R12 and T-R6 indicates recipient of T-Rapa cells manufactured for 12 days vs. 6 days. Disclosures: Levine: TxCell: Consultancy, Membership on an entity's Board of Directors or advisory committees; University of Pennsylvania: financial interest due to intellectual property and patents in the field of cell and gene therapy. Conflict of interest is managed in accordance with University of Pennsylvania policy and oversight, financial interest due to intellectual property and patents in the field of cell and gene therapy. Conflict of interest is managed in accordance with University of Pennsylvania policy and oversight Patents & Royalties. June:Novartis: Research Funding, institution owned patents have been licensed by Novartis, institution owned patents have been licensed by Novartis Patents & Royalties. Mato:Celgene, Milennium, Genentech, Seattle Genetics: Speakers Bureau.

Materialart: Online-Ressource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood.V120.21.471.471

Sprache: Englisch

Verlag: American Society of Hematology

Publikationsdatum: 2012

ZDB Id: 1468538-3

ZDB Id: 80069-7

In: Blood, American Society of Hematology, Vol. 113, No. 20 ( 2009-05-14), p. 4834-4840

Kurzfassung: Rituximab improves outcomes for persons with lymphoproliferative disorders and is increasingly used to treat immune-mediated illnesses. Recent reports describe 2 patients with systemic lupus erythematosus and 1 with rheumatoid arthritis who developed progressive multifocal leukoencephalopathy (PML) after rituximab treatment. We reviewed PML case descriptions among patients treated with rituximab from the Food and Drug Administration, the manufacturer, physicians, and a literature review from 1997 to 2008. Overall, 52 patients with lymphoproliferative disorders, 2 patients with systemic lupus erythematosus, 1 patient with rheumatoid arthritis, 1 patient with an idiopathic autoimmune pancytopenia, and 1 patient with immune thrombocytopenia developed PML after treatment with rituximab and other agents. Other treatments included hematopoietic stem cell transplantation (7 patients), purine analogs (26 patients), or alkylating agents (39 patients). One patient with an autoimmune hemolytic anemia developed PML after treatment with corticosteroids and rituximab, and 1 patient with an autoimmune pancytopenia developed PML after treatment with corticosteroids, azathioprine, and rituximab. Median time from last rituximab dose to PML diagnosis was 5.5 months. Median time to death after PML diagnosis was 2.0 months. The case-fatality rate was 90%. Awareness is needed of the potential for PML among rituximab-treated persons.

Materialart: Online-Ressource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood-2008-10-186999

Sprache: Englisch

Verlag: American Society of Hematology

Publikationsdatum: 2009

ZDB Id: 1468538-3

ZDB Id: 80069-7

In: Blood, American Society of Hematology, Vol. 122, No. 21 ( 2013-11-15), p. 626-626

Kurzfassung: Recent genome wide association studies (GWAS) of Hodgkin lymphoma (HL) have identified several associations at both HLA and non-HLA loci. However, much of HL heritability remains unexplained. Methods To identify novel risk loci, we performed a meta-analysis of 3 HL GWAS including a total of 1,810 cases and 7,879 controls. Results were replicated in an independent set of 1,163 cases and 2,580 controls, for a total of 3,097 and 11,097 cases and controls combined, respectively. participants in discovery and replication stages were of European descent. quality control and imputation we conducted a meta-analysis addressing 1,004,829 variants (λ= 1.10, λ1000= 1.03). Associations between SNP genotypes and HL risk were evaluated under a log-additive model of inheritance adjusting for sex, study center and significant principal components to control for population stratification. We performed an analysis with all HL cases and then conducted stratified analyses by histological subtype (classical, nodular sclerosis and mixed cellularity), age at diagnosis (nodular sclerosis among those diagnosed at 15- 35 years in all studies, and those diagnosed at 35 and older years in the European Study only) and EBV tumor status (negative and positive). We then used a bioinformatic approach (FunciSNP) to identify potential functional variants associated with HD risk correlated with risk loci of interest. We extracted publically available ENCODE data on biofeatures to identify potential functional motifs associated with the index SNP or correlated SNPs. Finally, we measured expression levels of the two alternative mRNA transcripts in lymphoblastoid cell lines (LCLs) from 49 post-therapy HL patients and 25 unaffected controls. RT-PCR was carried out in triplicate. Relative expression levels were calculated relative to TBP as housekeeping gene. Linear models were used to assess correlation between genotype and TCF3expression levels. Results The meta-analysis identified a novel susceptibility variant at chromosome 19p13.3 (rs1860661) associated with HL risk (Odds Ratio [OR]= 0.78, P=2.0*10-8, I2=0%). variant is located in intron 2 of TCF3 (also known as E2A), a regulator of B- and T-cell lineage commitment. was also significantly associated with HL (OR= 0.85, P=0.002) in the replication series of 1,281 cases and 3,218 controls. the combined analysis consisting of the discovery and replication sets, rs1860661was strongly associated with HL (OR=0.81,=3.5*10-10), with no evidence of heterogeneity between contributing studies (Phom=0.41, I2=0%). The number of G alleles defined by rs1860661 was significantly associated with a reduced risk of each HL subtype except EBV positive HL. rs1860661 and two correlated SNPs, rs10413888 (r2=0.90) and rs8103453 (r2=0.89) identified by FunciSNP analysis map in or near marks of open chromatin and in DNAse hypersensitivity sites in TCF3 in CD20+ B cell lines., the protective minor alleles of these SNPs as defined by the G-G-G haplotype map to the binding sites for ZBTB7a (rs10413888 and rs1860661) and (rs8103453) transcription factors, likely improving the binding efficiency to the sites which may result in increased transcription rates of TCF3. TCF3 is encoded by two alternative transcripts (E12 and E47). Higher expression levels of TCF3-E47, whose transcription start site is located close to rs1860661, was associated with the rs1860661-G allele in controls (P=0.02), but not in HL patients (P=0.22). Conclusion/Discussion TCF3 is essential for the commitment of lymphoid progenitors to both B-cell and T-cell lineage development. A molecular and phenotypic hallmark of classical HL is the loss of the B-cell phenotype in HRS cells, including lack of demonstrable B-cell receptor and most B-cell specific markers such as CD19 or CD20. HRS cells have a low level of TCF3, particularly homodimers of the isoform E47, due to expression of the ABF-1 and ID2 inhibitors that bind to TCF3. Thus, higher TCF3 levels in HRS precursor cells may lead to enhanced retention of the B cell phenotype, thereby conferring a protective effect. These data suggest a link between the 19p13.3 locus including TCF3 and HL risk, indicating that TCF3 could be relevant to HL etiology and pathogenesis. Disclosures: Link: Genentech: Consultancy; Millenium: Consultancy; Pharmacyclics: Consultancy; Spectrum: Consultancy.

Materialart: Online-Ressource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood.V122.21.626.626

Sprache: Englisch

Verlag: American Society of Hematology

Publikationsdatum: 2013

ZDB Id: 1468538-3

ZDB Id: 80069-7

In: Blood, American Society of Hematology, Vol. 134, No. Supplement_1 ( 2019-11-13), p. 318-318

Kurzfassung: The discovery that thalidomide derivatives recruit the E3 ligase CRBN to induce neomorphic degradation of proteins critical for multiple myeloma (MM) cells stimulated the research into proteolysis-targeting chimeric compounds (PROTACs), led to development of several CRBN- or VHL-based PROTACs against various oncoproteins and put a new spotlight on the biology and therapeutic targeting of E3 ligases in human neoplasias. However, so far only a few of the ~600 known/presumed E3 ligases have been leveraged for generation of PROTACs. The mechanisms regulating the function of most E3 ligases have not been systematically examined. Because the function of an E3 ligase is considered essential for anti-tumor activity of its respective PROTACs, we applied CRISPR knock-out (KO) systems to identify candidate regulators of E3 ligase function, via characterizing the the network of genes which modulate MM cell responses to PROTACs. We thus performed genome-scale CRISPR-based gene editing (for loss-of-function, LOF) studies in MM.1S cells treated with PROTACs targeting BET bromodomain proteins through MDM2 (A1874), CRBN (dBET6) or VHL (ARV-771 or MZ-1) or targeting CDK9 through CRBN (Thal-SNS-032); and validated key hits with individual sgRNAs in different MM cell lines. The top individual LOF events conferring resistance to PROTACs did not involve a compensatory mechanism or "work-around" the loss of the respective oncoprotein, but were predominantly associated with LOF of the respective E3 ligase; or with LOF for genes with known or plausible role in regulating the respective E3 ligases. For instance, sgRNAs against members of the COP9 signalosome complex decreased MM cell responses to CRBN- and (to a lesser extent) VHL-, but not MDM2-based PROTACs. PROTACs leveraging different E3 ligases were regulated by different cullin ring ligase (CRL) complex members (e.g. CUL2, RBX1, TCEB1, TCEB2 for VHL- vs. DDB1 for CRBN- vs. no CRL member for MDM2-based PROTACs) or E2 conjugating enzymes (UBE2R2 vs. UBE2G1 for VHL- vs. CRBN-based PROTACs). Collectively, these results suggest that MDM2 regulation is largely CRL- and COP9-signalosome independent; while VHL regulation is less COP9 signalosome-dependent compared to CRBN. These mechanistic differences suggest that PROTACs targeting the same oncoprotein through different E3 ligases should not be associated with cross-resistance, a result which we validated in experiments involving sequential administration of different PROTACs against BRD4/3/2. In turn, this observation implied that developing PROTACs that leverage a more extended spectrum of E3 ligases may facilitate sequential uses of existing and these new PROTACs to delay or prevent treatment resistance. Building on results of our genome-scale CRISPR essentiality screens, we examined the dependency landscape of known E3 ligases of MM (n=20 cell lines) and 500+ non-MM cell lines. CRBN is redundant for nearly all MM or non-MM cell lines tested, while most other E3 ligases leveraged for PROTACs (e.g. MDM2, BIRC2, DCAF15, DCAF16, RNF114) are essential for only modest or small subsets of human cancer cell lines, suggesting that resistance to respective PROTACs may readily emerge through LOF of these E3 ligases without major fitness cost to tumor cells. We thus sought to identify E3 ligases which are highly expressed in subsets of human tumor cell lines (at levels well above the large majority of normal tissues) and are major dependencies for these "high expressor" cell lines: we identified MDM2 as a major dependency for p53-wild-type cell lines (consistent with MDM2 role as E3 ligase for p53) and we validated this result by documenting the preferential activity of a MDM2-based PROTAC for BRD4/3/2 against p53 wild-type cells. We also identified other E3 ligases genes with well-known roles in tumor cell biology (e.g. members of anaphase promoting complex/cyclosome); as well as E3 ligases (e.g. KCMF1, RNF4) which, to our knowledge, have not been leveraged for design of PROTACs, but warrant consideration given their patterns of essentiality in "high expressor" tumor cells. Our study provides insights on differential regulation and distinct patterns of essentiality for different E3 ligases and informs the design of new PROTACs which leverage different E3 ligases to help delay/overcome treatment resistance in MM and beyond. Disclosures Schlossman: Millennium Pharmaceuticals, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited: Employment. Richardson:Oncopeptides: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees. Ebert:Broad Institute: Other: Contributor to a patent filing on this technology that is held by the Broad Institute.; Celgene: Research Funding; Deerfield: Research Funding. Tsherniak:Tango Therapeutics: Consultancy. Boise:Genentech Inc.: Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Honoraria, Research Funding. Gray:Gatekeeper, Syros, Petra, C4, B2S and Soltego.: Equity Ownership; Novartis, Takeda, Astellas, Taiho, Janssen, Kinogen, Voronoi, Her2llc, Deerfield and Sanofi.: Equity Ownership, Research Funding. Mitsiades:Takeda: Other: employment of a relative ; Ionis Pharmaceuticals: Honoraria; Fate Therapeutics: Honoraria; Arch Oncology: Research Funding; Sanofi: Research Funding; Karyopharm: Research Funding; Abbvie: Research Funding; TEVA: Research Funding; EMD Serono: Research Funding; Janssen/Johnson & Johnson: Research Funding.

Materialart: Online-Ressource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood-2019-130549

Sprache: Englisch

Verlag: American Society of Hematology

Publikationsdatum: 2019

ZDB Id: 1468538-3

ZDB Id: 80069-7

In: Blood, American Society of Hematology, Vol. 116, No. 24 ( 2010-12-09), p. 5111-5118

Kurzfassung: Invasive fungal infection (IFI) is a serious threat after allogeneic hematopoietic cell transplant (HCT). This multicenter, randomized, double-blind trial compared fluconazole (N = 295) versus voriconazole (N = 305) for the prevention of IFI in the context of a structured fungal screening program. Patients undergoing myeloablative allogeneic HCT were randomized before HCT to receive study drugs for 100 days, or for 180 days in higher-risk patients. Serum galactomannan was assayed twice weekly for 60 days, then at least weekly until day 100. Positive galactomannan or suggestive signs triggered mandatory evaluation for IFI. The primary endpoint was freedom from IFI or death (fungal-free survival; FFS) at 180 days. Despite trends to fewer IFIs (7.3% vs 11.2%; P = .12), Aspergillus infections (9 vs 17; P = .09), and less frequent empiric antifungal therapy (24.1% vs 30.2%, P = .11) with voriconazole, FFS rates (75% vs 78%; P = .49) at 180 days were similar with fluconazole and voriconazole, respectively. Relapse-free and overall survival and the incidence of severe adverse events were also similar. This study demonstrates that in the context of intensive monitoring and structured empiric antifungal therapy, 6-month FFS and overall survival did not differ in allogeneic HCT recipients given prophylactic fluconazole or voriconazole. This trial was registered at www.clinicaltrials.gov as NCT00075803.

Materialart: Online-Ressource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood-2010-02-268151

Sprache: Englisch

Verlag: American Society of Hematology

Publikationsdatum: 2010

ZDB Id: 1468538-3

ZDB Id: 80069-7

In: Blood, American Society of Hematology, Vol. 132, No. Supplement 1 ( 2018-11-29), p. 1367-1367

Kurzfassung: Heterobifunctional proteolysis-targeting chimeric compounds leverage the activity of E3 ligases (e.g. CRBN and VHL) to induce neopmorphic ubiquitination and proteasomal degradation of target oncoproteins, with potent preclinical activity against diverse neoplasias. Despite intense recent efforts to develop pharmacological "degraders" against many different oncoproteins, the mechanisms regulating tumor cell sensitivity to different classes of these "degraders" remain incompletely understood. To address this question in an unbiased manner, we performed genome-scale CRISPR/Cas9-based gene editing loss-of-function (LOF) studies in MM.1S multiple myeloma (MM) cells treated with CRBN-mediated degraders of BET bromodomain proteins (dBET6) or CDK9 (Thal-SNS-032); or with VHL-mediated degraders of BET bromodomain proteins (ARV-771 or MZ-1). We observed that MM cell resistance to any of these "degraders" does not involve genes with recurrent LOF in MM patients and association with high-risk MM (e.g. for TP53, PTEN, negative regulators of cell cycle, et.c.), suggesting that these degraders may exhibit activity against tumor cells with prognostically adverse genetic features. In tumor cells resistant to the CRBN-mediated degraders dBET6 and Thal-SNS-032, we observed significant enrichment of sgRNAs targeting CRBN itself or (to a lesser extent) other components or regulators of its cullin RING ligase (CRLCUL4A) complex, including members of the COP9 signalosome (COPS7A, COPS7B, COPS2, COPS3, COPS8, GPS1, etc.), DDB1, or the E2 ubiquitin conjugating enzyme UBE2G1. In tumor cells resistant to the VHL-mediated degraders MZ-1 and ARV-771, we observed pronounced enrichment of sgRNAs for CUL2, VHL itself, other members (e.g. RBX1, elongin B/C [TCEB1, TCEB2] of the CUL2 complex with VHL), as well as COP9 signalosome genes (COPS7B, COPS8) and UBE2R2. We also validated, using individual sgRNAs for several of these candidate genes that their CRISPR knockout can decrease tumor cell response to dBET6 and Thal-SNS-032 treatment (e.g. for CRBN, COPS7B, COPS2, or COPS8) or MZ-1 and ARV-771 (e.g. for VHL, COP7B and COPS8). Notably, the sgRNAs against COP9 signalosome genes conferred less pronounced decrease in sensitivity to VHL-, than CRBN-based, degraders, suggesting that COP9 signalosome loss has differential roles in the function of CUL4ACRBN vs. CUL2VHL and potentially other CRL complexes. Tumor cells isolated from our CRISPR knockout screens with confirmed resistance to a given degrader were then treated with other degraders operating through the same or different E3 ligase; and against the same or different oncoprotein: we observed cross-resistance between degraders operating through the same E3 ligase against different oncoproteins, but not for degraders targeting the same protein via different E3 ligase/CRLs: this result is consistent with our observation for substantial gene-level differences (despite pathway-level similarities) for resistance mechanisms for CRBN- vs. VHL-based degraders. In conclusion, our study systematically defined at genome-scale the resistance mechanisms of tumor cells against degraders which leverage the same E3 ligase against different targets; or target the same oncoprotein through different E3 ligases/CRL complexes. We observed that for multiple types of degraders, tumor cell resistance is primarily mediated by prevention of, rather than adaptation to, breakdown of the target oncoprotein. The observed pathway-level similarities and major individual gene-level differences in resistance mechanisms for CRBN- and VHL-mediated degraders likely reflects the different composition and regulation of the respective CRL complexes mediating the action of these classes of degraders Our observations suggest that preventing or delaying resistance to pharmacological degradation of oncoproteins may require concurrent or sequential/alternating use of degraders operating through different E3 ligases and ideally, different CRL complexes; while synthetic lethal strategies to prevent COP9 signalosome LOF may also be contemplated to counteract a common, but quantitatively less pronounced, potential mechanism of resistance for several different classes of degraders. Collectively, our study highlights important new directions in the development of new pharmacological degraders for blood cancers and other neoplasias. Disclosures Richardson: Karyopharm: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Research Funding; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees. Licht:Celgene: Research Funding. Boise:Abbvie: Consultancy; AstraZeneca: Honoraria. Gray:C4 Therapeutics: Consultancy. Mitsiades:TEVA: Research Funding; Janssen/ Johnson & Johnson: Research Funding; EMD Serono: Research Funding; Takeda: Other: employment of a relative; Abbvie: Research Funding.

Materialart: Online-Ressource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood-2018-99-116232

Sprache: Englisch

Verlag: American Society of Hematology

Publikationsdatum: 2018

ZDB Id: 1468538-3

ZDB Id: 80069-7

In: Blood, American Society of Hematology, Vol. 134, No. Supplement_1 ( 2019-11-13), p. 3317-3317

Kurzfassung: Introduction: The introduction of next-generation sequencing (NGS) has expedited the discovery of novel genetic lesions in acute myeloid leukemia (AML), thereby allowing better risk stratification with respect to overall survival (OS). We have previously reported that AML patients with PTPN11 and NPM1 mutations had longer OS following chemotherapy, while those carrying mutations in ASXL1, JAK2, RUNX1, TP53 and SRSF2 had a shorter OS (Daher-Reyes,ASH 2018). Little is known, however, regarding the impact of genetic profiles (somatic mutations and cytogenetic abnormalities) at initial AML diagnosis on the treatment outcomes following allogeneic hematopoietic stem cell transplantation (HCT). Methods & Patients: We enrolled AML patients who had available NGS data at time of initial diagnosis as part of the AGILE project between February 2015 and December 2018, and who subsequently underwent allogeneic HCT. NGS was performed on DNA samples isolated from peripheral blood or bone marrow samples at diagnosis. Analysis was performed using the TruSight Myeloid Sequencing Panel on the MiSeq sequencer (Illumina; San Diego, CA). Transplant outcomes (overall survival (OS), relapse-free survival (RFS), relapse incidence (RI), and non-relapse mortality (NRM)) after HCT were compared according to genetic profiles defined at diagnosis. Survival analysis for OS and RFS was performed using Cox's proportional hazard model, while the Fine-Gray model was used for RI and NRM analyses. Variables considered in the model included CR status prior to HCT (CR1 vs. beyond CR1), de novo AML (vs. secondary/therapy-related AML), induction chemotherapy used (3+7 vs. others), conditioning regimen (myeloablative vs. reduced intensity), WBC, age, donor type, mutation status of commonly mutated genes, and the composite adverse genetic profile (defined as having at least one of monosomal karyotype (MK), TP53 mutation, del(5), complex karyotype (CK), and monosomy 7), given that these 5 features were highly co-occurring, adverse prognostic factors (Figure 1A). Results: We identified 435 patients in whom frontline NGS was performed, of whom a total of 178 patients (40.9%) received HCT and were included in the final analysis. A total of 598 (median 4, IQR 2-5) mutations were identified in 165 patients (n=165/178, 92.7%). Among 54 genes in the panel, 12 genes were mutated in more than 10% of the cohort, with the most commonly mutated genes being DNMT3A (30.3%), TET2 (25.3%), NPM1 (22.5%), RUNX1 (18.5%), IDH2 (16.9%), FLT3 (15.7%), ASXL1 (12.4%), BCOR (12.4%), CEBPA (11.2%), NRAS (11.2%), IDH1 (10.1%), and SRSF2 (10.1%). In univariate analysis, the groups with a composite adverse genetic profile (n=30/178, 16.9%) showed decreased OS (HR 2.19 [1.30-3.67]; p=0.003), while patients harbouring spliceosome gene (SF3B1, SRSF2, U2AF1, and ZRSR2) mutations (n=37/178, 20.8%) had longer OS (HR 0.39 [0.18-0.85] ; p=0.018), with 2-year OS rates of 24.9% and 57.9%, respectively (p=0.002)) (Figure 1B). The composite adverse genetic profile was also associated with shorter RFS (HR 2.23 [1.34-3.69]; p=0.002), while spliceosome gene mutations were associated with longer RFS (HR 0.42 [0.20-0.88] ; p=0.022), with 2-year RFS rates of 23.7% vs. 57.9%, respectively (p=0.001)). The composite adverse genetic profile was also associated with higher RI (HR 2.94 [1.52-5.66]; p=0.001), with 2-year RI rates of 47.2% vs. 17.2%, respectively, for patients with and without adverse genetic features (p=0.002) (Figure 1C). Neither the composite adverse genetic profile, nor spliceosome gene mutations, were associated with NRM, with HR of 1.21 [0.55-2.65] , p=0.64) and 0.45 [0.16-1.31], p=0.15, respectively (Figure 1D). Multivariate analyses confirmed that the composite adverse genetic profile and spliceosome gene mutations were independent prognostic factors for OS, RFS, and RI (p=0.004, p=0.0 02, and p=0.001, respectively) and for OS and RFS (p=0.020 and p=0.022, respectively). Conclusion: In our cohort, the composite adverse genetic profile (i.e. having at least one of MK, TP53 mutation, del(5), CK and monosomy 7 remained as a poor prognostic factor even after allogeneic HCT. To clarify the role of genetic risk stratification in HCT, further analysis using a larger cohort is warranted. In addition, a comparative analysis between HCT vs no-HCT groups according to the genetic profile, is ongoing in a in a larger patient cohort. Figure 1 Disclosures Michelis: CSL Behring: Other: Financial Support. Mattsson:Gilead: Honoraria; Celgene: Honoraria; Therakos: Honoraria. Schimmer:Novartis Pharmaceuticals: Consultancy; Otsuka Pharmaceuticals: Consultancy; Jazz Pharmaceuticals: Consultancy; Medivir Pharmaceuticals: Research Funding. McNamara:Novartis Pharmaceutical Canada Inc.: Consultancy. Maze:Pfizer Inc: Consultancy; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees. Gupta:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sierra Oncology: Honoraria, Membership on an entity's Board of Directors or advisory committees; Incyte: Honoraria, Research Funding; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Yee:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astex: Research Funding; Hoffman La Roche: Research Funding; MedImmune: Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Merck: Research Funding; Millennium: Research Funding; Astellas: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees. Minden:Trillium Therapetuics: Other: licensing agreement. Schuh:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Agios: Honoraria; Teva Canada Innovation: Honoraria, Membership on an entity's Board of Directors or advisory committees; Astellas: Honoraria, Membership on an entity's Board of Directors or advisory committees; Jazz: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Materialart: Online-Ressource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood-2019-125780

Sprache: Englisch

Verlag: American Society of Hematology

Publikationsdatum: 2019

ZDB Id: 1468538-3

ZDB Id: 80069-7

In: Blood, American Society of Hematology, Vol. 118, No. 10 ( 2011-09-08), p. 2653-2655

Kurzfassung: The syndrome of monocytopenia, B-cell and NK-cell lymphopenia, and mycobacterial, fungal, and viral infections is associated with myelodysplasia, cytogenetic abnormalities, pulmonary alveolar proteinosis, and myeloid leukemias. Both autosomal dominant and sporadic cases occur. We identified 12 distinct mutations in GATA2 affecting 20 patients and relatives with this syndrome, including recurrent missense mutations affecting the zinc finger-2 domain (R398W and T354M), suggesting dominant interference of gene function. Four discrete insertion/deletion mutations leading to frame shifts and premature termination implicate haploinsufficiency as a possible mechanism of action as well. These mutations were found in hematopoietic and somatic tissues, and several were identified in families, indicating germline transmission. Thus, GATA2 joins RUNX1 and CEBPA not only as a familial leukemia gene but also as a cause of a complex congenital immunodeficiency that evolves over decades and combines predisposition to infection and myeloid malignancy.

Materialart: Online-Ressource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood-2011-05-356352

Sprache: Englisch

Verlag: American Society of Hematology

Publikationsdatum: 2011

ZDB Id: 1468538-3

ZDB Id: 80069-7