Blood Cancer Discovery最新文献

{"title":"Abstract A05: Multiplexed CyTOF analysis of FLT3-ITD AML landscape identifies proteomic profiles associated with resistance to targeted therapies","authors":"M. Muftuoglu, M. Yilmaz, Mahesh Basyal, Li Li, N. Daver, M. Andreeff","doi":"10.1158/2643-3249.aml23-a05","DOIUrl":"https://doi.org/10.1158/2643-3249.aml23-a05","url":null,"abstract":"\u0000 Targeted therapies(TT) combining FLT3 inhibitors with hypomethylating agents (HMA) and Venetoclax (Ven) are highly effective against FLT3-ITD acute myeloid leukemia (AML) with high response rates. Signaling mutations along with emergence of rarer mutations are the key contributors to primary and secondary resistance to TT. We hypothesize that resistant leukemia clones have unique proteomic profiles that facilitate survival under therapy pressure(TP) and deciphering proteomic profiles at the single-cell level will delineate resistance mechanisms and adaptive responses driven by TP. We performed multiplexed single-cell proteomic analysis of serial PB and BM samples (n:162) from patients treated with FLT3i+HMA+/-VEN using CyTOF. Unsupervised analysis identified leukemia cells and non-malignant cellular elements of the leukemia compartment in an unbiased manner. Next, we interrogated the leukemia proteomic landscape to identify leukemia associated proteomic features. Since Ven targets BCL2 and FLT3i modulates the expression of anti-apoptotic molecules we assessed the expression of apoptosis regulators and found that leukemia cells with immature phenotype, including those with leukemia stem cell(LSC) phenotype, almost always expressed moderate-high levels of BCL2. Monocytic cells(MC) lacked BCL2 expression and had the highest levels of MCL1. Despite expressing moderate levels of MCL1 and BCL-XL, TT was effective in substantially eliminating CD34+ immature leukemia cells. We observed a relative enrichment of MCs, either benign or malignant, after TT. Since cells with MC phenotype were inherently resistant to TT we hypothesized that leukemia cell subsets having similar proteomic profiles to MCs will persist after TT. Phenotypic interrogation of leukemia cells (UMAP) revealed that LSCs generally clustered on the opposite pole distant from MCs and leukemia cells on poles facing MCs were more differentiated. Remarkably, FLT3-ITD mutation partners differentially altered the proteomic landscape. NPM1 mutant FLT3-ITD AML cells displayed a less diverse leukemia architectural organization with differentiation block. Contrarily, signaling mutations diversified the leukemia landscape into a diverse continuum of differentiation states. We also observed that RAS/MAPK mutations could overcome differentiation block and gave rise to a differentiation continuum encompassing less-differentiated, transitional and differentiated leukemia cells. The transitional CD34+ leukemia cells, mapped in close vicinity to MCs, and differentiated MCs that preferentially persisted at D28, had active signaling pathways and expressed CD36. The presence of CD34+ leukemia cells with persistent signaling at D28 was indicative of poor clinical outcomes. Conclusion: Multiplexed single-cell proteomic analysis identified a unique mode of resistance and proteomic features of surviving cells in with FLT3-ITD AML patients treated with TT, and elucidated how different mutation partners in FLT3-IT","PeriodicalId":29944,"journal":{"name":"Blood Cancer Discovery","volume":" ","pages":""},"PeriodicalIF":11.2,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43106890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract A50: Distinguishing Mosaic Li Fraumeni Syndrome, Clonal Hematopoiesis and Incidental Myeloid Neoplasms in Patients with Solid Tumors with Pathogenic TP53 Mutations Identified by Germline Testing or Cell-Free Circulating DNA Sequencing","authors":"S. Loghavi, Yoheved Gerstein, M. Routbort, K. Patel, Koichi Takahashi, M. Daniels, Julie B Moskowitz, D. Hammond, K. Chien, L. Medeiros, F. Ravandi, H. Kantarjian, G. Garcia-Manero, B. Arun, Joseph D. Khoury, C. Dinardo","doi":"10.1158/2643-3249.aml23-a50","DOIUrl":"https://doi.org/10.1158/2643-3249.aml23-a50","url":null,"abstract":"\u0000 The incorporation of panel-based germline genetic testing for assessment of pathogenic or likely pathogenic variants associated with increased risk of breast, ovarian, prostatic and pancreatic cancer in NCCN guidelines and wide adoption of cell-free circulating DNA sequencing (liquid biopsy) for patients with advanced solid tumors has increased the identification of pathogenic TP53 variants in blood of patients with solid tumors. The variant allelic frequency (VAF) of the pathogenic variant is often used to help infer the compartment of origin (germline vs somatic) with near heterozygous (~50%) VAF favoring germline; however, when VAF is low (sub heterozygous) potential considerations include mosaic Li Fraumeni syndrome, clonal hematopoiesis, or incidental myeloid neoplasms, and determining the origin of the TP53 mutation can be a challenge with important surveillance and treatment implications. We describe a cohort of patients with solid tumors or hematologic malignancies in whom pathogenic or likely pathogenic TP53 variants of uncertain origin were identified by clinical genetic testing of peripheral blood, next generation sequencing (NGS) using an 81 gene hematologic malignancy-based panel, or cell-free DNA sequencing/liquid biopsy. In a subset of patients for whom solid tumor, adjacent normal tissue and/or bone marrow (BM) was available, immunohistochemistry for p53 protein was performed. Patients (n= 17) included 11 (61%) women and 7 (39%) men with a median age of 54 years (range 8-7) at initial cancer diagnosis, with 17 unique TP53 variants with a median VAF of 16% (range, 2-50%). The most common indication for referral for additional investigation of the TP53 origin was sub-heterozygous VAF on germline testing of blood (8/47%) or saliva (1/6%); TP53 variant identified in plasma when the concurrent solid tumor was TP53 wild-type (3/18%) followed by presence of a pathogenic TP53 variant in remission BM of patients with history of hematologic malignancies (4/24%). Additional germline testing of skin fibroblasts and/or BM examination was performed in in 9 (53%) and 8 (47%) patients, respectively. p53 IHC was performed on 3 BM biopsies and 2 solid tumor tissues. A multimodality/multidisciplinary interpretation of these results allowed appropriate classification of the TP53 variants in 12/18 patients (67%). These included Li Fraumeni syndrome (5/12; 42%); clonal hematopoiesis (5/12; 42%); donor-derived clonal hematopoiesis (1/12;8%) and therapy-related myelodysplastic syndrome (1/12; 8%) patients. Appropriate awareness and distinction of clonal hematopoiesis and potential myeloid neoplasms from mosaic germline TP53 in the setting of subheterozygous VAF identified on peripheral blood or bone marrow analyses can be challenging. Multimodality testing and a multidisciplinary approach for accurate interpretation is required. Immunohistochemical staining for p53 can be useful in making this distinction in a subset of patients.\u0000 Citation Format: Sana","PeriodicalId":29944,"journal":{"name":"Blood Cancer Discovery","volume":" ","pages":""},"PeriodicalIF":11.2,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43469199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract A46: Heterozygous mutations in DDX41 cause erythroid progenitor cell defects and cooperate with p53 mutations to cause hematologic malignancy","authors":"Timothy M. Chlon, Emily Stepanchick, Analise Sulentic, Andrew F. Wilson, D. Starczynowski","doi":"10.1158/2643-3249.aml23-a46","DOIUrl":"https://doi.org/10.1158/2643-3249.aml23-a46","url":null,"abstract":"\u0000 Germline mutations in the RNA Helicase gene DDX41 are the most common cause of inherited susceptibility to adult MDS and AML. These mutations are always heterozygous and are typically frameshifts, causing loss of functional protein. We recently reported that at least one functional copy of DDX41 is essential for hematopoiesis, and that DDX41 is required for ribosome biogenesis (Chlon et al., Cell Stem Cell 2021). While biallelic DDX41 mutations cause dramatic defects in hematopoiesis, the role of heterozygous mutations in MDS pathogenesis is not yet understood. DDX41 mutation carriers frequently experience idiopathic cytopenias of unknown significance (ICUS) prior to MDS onset, suggesting that underlying hematopoietic defects contribute to MDS/AML (Choi et al., Haemotologica 2021). The majority of DDX41-mutant MDS patients have refractory anemia, indicating that the erythroid lineage is particularly affected in these patients (Sebert et al., Blood 2019). Since ribosome defects are a common cause of inherited anemias and also contribute to MDS pathogenesis, we characterized the effect of heterozygous DDX41 mutations on erythropoiesis in murine and human models. Mice that were transplanted with Ddx41+/− bone marrow develop anemia at 12-15 months post-transplant. At younger ages, these mice have normal hematopoietic indices, but when stress erythropoiesis is induced by Pheylhydrazine-treatment, the Ddx41+/− mice have prolonged anemia. These observations indicate that heterozygous loss of DDX41 causes defects in erythropoiesis during stress and aging. We further characterized the effect of Ddx41-hetrozyogisty on erythroid progenitor function in vitro. In colony assays, we found that Ddx41+/− HSPC form fewer BFU-E but comparable numbers of myeloid colonies. In liquid culture erythroid differentiation cultures, we found that Ddx41+/− HSPC produce fewer CD71+ Ter119+ progenitors than controls. Mechanistically, we found that in vitro-derived erythroid progenitors from both mice and cell line models had decreased protein translation, suggesting that ribosome defects underlie the observed inefficiency in erythropoiesis. In congenital ribosomopathy diseases, ribosome defects lead to p53 activation which contributes to defects in erythropoiesis. Interestingly, TP53 mutations are common in DDX41-mutant MDS/AML (Sebert et al., Blood 2019), suggesting that the ribosome deficiency selects for these mutations. To assess the role of p53 mutations in the development of DDX41-mutant MDS, we generated Ddx41+/−;p53+/− mice and transplanted the bone marrow into lethally-irradiated recipients and followed the mice for 1 year. These mice developed a lethal MDS-like phenotype at 7-12 months post-transplant while control mice lived until the end of the study period. The sick mice had anemia and other cytopenias accompanied by enlarged spleens and dysplastic myeloid cells. Collectively, these results indicate that p53 mutations cooperate with Ddx41-heterozygosity to promo","PeriodicalId":29944,"journal":{"name":"Blood Cancer Discovery","volume":" ","pages":""},"PeriodicalIF":11.2,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42113875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract A48: Aging-related, Senescence-associated Secretory Phenotype and Allogeneic Hematopoietic Cell Transplantation Outcomes in Older Adults","authors":"R. Lin, P. Wong, J. Flynn, Erika R Ritter, Caleb Ho, J. Ruiz, A. Jakubowski, E. Papadopoulos, B. Shaffer, H. Castro-Malaspina, C. Cho, Doris Ponce, J. Barker, R. Tamari, C. Sauter, B. Gyurkocza, M. V. D. van den Brink, J. Young, M. Perales, S. Devlin, S. Giralt","doi":"10.1158/2643-3249.aml23-a48","DOIUrl":"https://doi.org/10.1158/2643-3249.aml23-a48","url":null,"abstract":"\u0000 Introduction: Older adults with hematologic malignancies such as AML and MDS increasingly undergo allogeneic hematopoietic cell transplantation (alloHCT). The impact of the aging host environment, especially cellular senescence, remains unexplored, however.\u0000 Objectives: We hypothesize that pre-transplant senescence-associated secretary phenotype (SASP) is associated with alloHCT outcomes among older patients and tested it in this biomarker correlative study.\u0000 Methods: We measured ten SASP-related cytokines (IFNγ, IL1β, IL2, IL4, IL6, IL8, IL10, IL12, IL13, and TNFα, and C-reactive protein (CRP) from pre-transplant plasma samples of 155 patients (>50 years) who had undergone alloHCT at MSKCC from 2011 to 2019 for acute leukemias and other myeloid malignancies. Expression of aging biomarker p16 was measured on a subset of patients by immunohistochemistry.\u0000 Results and Discussion: The median age was 64.1 years (IQR 58.3 – 67.8). Diseases included 57% acute leukemias (AML and ALL) and 43% MDS/MPN. KPS was <90 in 43% and HCT-CI was >3 in 53% of patients. With median follow-up of 61 months for survivors, the 5-year OS and PFS is 50% and 46%, respectively. The 2-year cumulative incidence of non-relapse mortality (NRM) and relapse is 18% and 31%, respectively. At the baseline, these SASP-related cytokines have variable degree of association with KPS, chronologic age, and disease risk. IL2 trended toward significant positive association with OS (HR 1.19, 95% CI 1-1.43, p=0.052) and was significantly associated with PFS (HR 1.21, 95% CI 1.02-1.44, p=0025) in univariate analysis, but not in multivariate analysis after adjusting for clinical characteristics. No cytokine was associated with NRM. IL2 and IL4 were associated with relapse in univariate but not multivariate analysis. Several cytokines including IL12 p70, IL13, IL4, and TNFα were associated with 100d grade II-IV acute GVHD in patients who received CNI-based GVHD prophylaxis. In summary, we found potential association of SASP-related cytokines with patient characteristics and transplant outcomes. We aim to validate these findings and examine their therapeutic potential to improve alloHCT outcomes.\u0000 Citation Format: Richard J Lin, Phillip Wong, Jessica R Flynn, Erika R Ritter, Caleb Ho, Josel D Ruiz, Ann A Jakubowski, Esperanza B Papadopoulos, Brian C Shaffer, Hugo R Castro-Malaspina, Christina J Cho, Doris R Ponce, Juliet N Barker, Roni Tamari, Craig S Sauter, Boglarka Gyurkocza, Marcel van den Brink, James W Young, Miguel-Angel Perales, Sean M Devlin, Sergio A Giralt. Aging-related, Senescence-associated Secretory Phenotype and Allogeneic Hematopoietic Cell Transplantation Outcomes in Older Adults [abstract]. In: Proceedings of the AACR Special Conference: Acute Myeloid Leukemia and Myelodysplastic Syndrome; 2023 Jan 23-25; Austin, TX. Philadelphia (PA): AACR; Blood Cancer Discov 2023;4(3_Suppl):Abstract nr A48.","PeriodicalId":29944,"journal":{"name":"Blood Cancer Discovery","volume":" ","pages":""},"PeriodicalIF":11.2,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42262431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract A19: Targeting epigenetic regulators to override cellular identity programs and induce therapeutic differentiation in MLL-rearranged acute myeloid leukemia","authors":"A. Blanco","doi":"10.1158/2643-3249.aml23-a19","DOIUrl":"https://doi.org/10.1158/2643-3249.aml23-a19","url":null,"abstract":"\u0000 Acute myeloid leukemia (AML) is a poor-prognosis disease that is universally characterized by a prominent differentiation block. Chemotherapeutic regimens and disease outcomes have not changed in decades, and there is great need for novel therapeutic treatments and approaches. Differentiation therapy is a fundamentally different therapy that aims to reactivate latent maturation programs to induce proliferation arrest and apoptosis. This approach is curative in the promyelocytic AML subtype but not others. It is therefore critical to identify the enforcers of differentiation arrest in non-APL AML. Here, we performed a cell-fate selection CRISPR screen for chromatin factors whose inhibition promotes AML cell differentiation. We found that both genetic and chemical inhibition of the histone acetyltransferase KAT6A induces myeloid maturation, most prominently in MLL-rearranged AML. KAT6A loss markedly reduces self-renewal and extinguishes the proliferative capacity of AML cells. Through ChIP-seq, RNA-seq, and clinical dataset analyses, we found that KAT6A is the likely initiator of a newly-described \"writer-reader\" module that drives oncogene expression in AML. KAT6A catalyzes promoter H3K9 acetylation, which is bound by the H3K9ac reader ENL, leading to Super-elongation complex recruitment and release of paused RNA PolII at oncogenic loci such as MYC. KAT6A is elevated in human AMLs compared to matched normal tissue, and its downregulation correlates with monocytic differentiation in clinical AML datasets. These findings suggest the potential of targeting KAT6A and/or ENL to disrupt this writer-reader module and ablate downstream MYC transcriptional programs in MLL-rearranged AML. This strategy may be viable in the near future, as a recently developed KAT6A/B inhibitor has already entered clinical trials for breast cancer. In follow-up work, we performed differentiation-specific \"synergy screens,\" in which we delivered sgRNA libraries to U937 cells and ER-Hoxb8 cells treated with or without an LSD1 inhibitor (LSD1i). We identified multiple genes whose knockout synergized with LSD1i treatment to induce complete, terminal differentiation with low toxicity. Genetic results were confirmed with small molecule inhibitors of selected hits, and the most synergistic drug combination was pursued further. We found that AML cells dependent on hyperactivity of both Hoxa9 and Meis1 are most sensitive to this drug combination. Preliminary data suggest that LSD1i treatment alone fails to downregulate Meis1 expression, and that the ability of the second drug to fully ablate Meis1 is the likely mechanism underlying the observed synergy. Importantly, the second drug is also in clinical trials and will be discussed in the abstract presentation. Altogether, this work advances our understanding of the AML differentiation block and nominates a specific drug combination for AML differentiation therapy.\u0000 Citation Format: Andres Blanco. Targeting epigenetic regulators to o","PeriodicalId":29944,"journal":{"name":"Blood Cancer Discovery","volume":" ","pages":""},"PeriodicalIF":11.2,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48926955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract A39: Role of LARP1 in the leukemogenesis of Acute Myeloid Leukemia","authors":"D. A. Nahotko, Aneta Baran, Mariafausta Fischietti, E. Beauchamp, L. Platanias","doi":"10.1158/2643-3249.aml23-a39","DOIUrl":"https://doi.org/10.1158/2643-3249.aml23-a39","url":null,"abstract":"Mammalian target of rapamycin (mTOR) is a strong driver of tumorigenesis in multiple types of tumors, however targeting mTOR for cancer therapy has yielded only limited success. This may be explained in part by signaling redundancy with other pathways, such as CDK9 mTOR-Like (CTORC) complexes, recently described by our group. One of the binders common to mTORC1 and CTORC2 is La related protein 1 (LARP1). LARP1 influences ribosome biogenesis by regulating translation of 5'terminal oligopyrimidine tract (5’ TOP) containing mRNAs, which often encode ribosomal proteins and translation factors. Here, we validate LARP1 as common target of mTORC1 and CTORC2 as well as investigate its influence on leukemogenesis. To explore LARP1’s role in leukemogenesis we utilized CRISPR/CAS9 technology to create OCI-AML5 and U937 LARP1 knockout (KO) cells. Loss of LARP1 expression significantly diminished proliferation potential of AML cell lines both in vitro as well as in vivo when implanted into the flank of athymic nude mice as xenografts. Additionally, primary CD34+ leukemia cells were transfected with LARP1 targeting or scrambled siRNA and leukemic progenitor growth was assessed in methocellulose colony formation assays. We observed suppression of leukemic progenitors colony forming ability in LARP1 siRNA transfected cells, compared to the Ctrl siRNA transfected cells. We also determined enhanced sensitivity of Larp1 KO cell lines to standard chemotherapy agents such Azacitidine, Cytarabine and Venetoclax. We employed polysome profiling to compare global translation levels between Larp1 KO and control U937 cells. Our polysomal profiling results show that KO of LARP1 in U937 cells reduces global translation and ribosome biogenesis as expected as we observed a suppression of both monosomal and polysomal peaks. In summary, Larp1 is important for leukemogenesis and influences their response to treatment with currently used chemotherapy agents. These observations together suggest that LARP1 is a promising target for development of novel antileukemia approaches. Citation Format: Dominik A Nahotko, Aneta H Baran, Mariafausta Fischietti, Elspeth M Beauchamp, Leonidas C Platanias. Role of LARP1 in the leukemogenesis of Acute Myeloid Leukemia [abstract]. In: Proceedings of the AACR Special Conference: Acute Myeloid Leukemia and Myelodysplastic Syndrome; 2023 Jan 23-25; Austin, TX. Philadelphia (PA): AACR; Blood Cancer Discov 2023;4(3_Suppl):Abstract nr A39.","PeriodicalId":29944,"journal":{"name":"Blood Cancer Discovery","volume":" ","pages":""},"PeriodicalIF":11.2,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46939477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Defective Immunity Against SARS-CoV-2 Omicron Variants Despite Full Vaccination in Hematologic Malignancies.","authors":"Laurence Zitvogel,&nbsp;Lisa Derosa,&nbsp;Guido Kroemer","doi":"10.1158/2643-3230.BCD-22-0213","DOIUrl":"10.1158/2643-3230.BCD-22-0213","url":null,"abstract":"<p><strong>Summary: </strong>In patients with multiple myeloma, completion of mRNA-based vaccination schemes failed to yield detectable SARS-CoV-2 Omicron-neutralizing antibodies and S1-RBD-specific CD8+ T cells in approximately 60% and 80% of the cases, respectively. Patients who develop breakthrough infections exhibited very low levels of live-virus neutralizing antibodies and the absence of follicular T helper cells. See related article by Azeem et al., p. 106 (9). See related article by Chang et al., p. 1684 (10).</p>","PeriodicalId":29944,"journal":{"name":"Blood Cancer Discovery","volume":"4 3","pages":"172-175"},"PeriodicalIF":11.2,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10150292/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9875791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular Evolution of Classic Hodgkin Lymphoma Revealed Through Whole-Genome Sequencing of Hodgkin and Reed Sternberg Cells.","authors":"Francesco Maura, Bachisio Ziccheddu, Jenny Z Xiang, Bhavneet Bhinder, Joel Rosiene, Federico Abascal, Kylee H Maclachlan, Kenneth Wha Eng, Manik Uppal, Feng He, Wei Zhang, Qi Gao, Venkata D Yellapantula, Vicenta Trujillo-Alonso, Sunita I Park, Matthew J Oberley, Elizabeth Ruckdeschel, Megan S Lim, Gerald B Wertheim, Matthew J Barth, Terzah M Horton, Andriy Derkach, Alexandra E Kovach, Christopher J Forlenza, Yanming Zhang, Ola Landgren, Craig H Moskowitz, Ethel Cesarman, Marcin Imielinski, Olivier Elemento, Mikhail Roshal, Lisa Giulino-Roth","doi":"10.1158/2643-3230.BCD-22-0128","DOIUrl":"10.1158/2643-3230.BCD-22-0128","url":null,"abstract":"<p><p>The rarity of malignant Hodgkin and Reed Sternberg (HRS) cells in classic Hodgkin lymphoma (cHL) limits the ability to study the genomics of cHL. To circumvent this, our group has previously optimized fluorescence-activated cell sorting to purify HRS cells. Using this approach, we now report the whole-genome sequencing landscape of HRS cells and reconstruct the chronology and likely etiology of pathogenic events leading to cHL. We identified alterations in driver genes not previously described in cHL, APOBEC mutational activity, and the presence of complex structural variants including chromothripsis. We found that high ploidy in cHL is often acquired through multiple, independent chromosomal gains events including whole-genome duplication. Evolutionary timing analyses revealed that structural variants enriched for RAG motifs, driver mutations in B2M, BCL7A, GNA13, and PTPN1, and the onset of AID-driven mutagenesis usually preceded large chromosomal gains. This study provides a temporal reconstruction of cHL pathogenesis.</p><p><strong>Significance: </strong>Previous studies in cHL were limited to coding sequences and therefore not able to comprehensively decipher the tumor complexity. Here, leveraging cHL whole-genome characterization, we identify driver events and reconstruct the tumor evolution, finding that structural variants, driver mutations, and AID mutagenesis precede chromosomal gains. This article is highlighted in the In This Issue feature, p. 171.</p>","PeriodicalId":29944,"journal":{"name":"Blood Cancer Discovery","volume":"4 3","pages":"208-227"},"PeriodicalIF":11.5,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10150291/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9888501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract A38: Pediatric Germline CSF3R T618I mutation gives insight into disease progression and long-term therapy options of Chronic Neutrophilic Leukemia","authors":"Kecheng Zhang, M. Rees, M. Khanlari, Laura Rooms, Raul C. Ribeiro, M. Wlodarski","doi":"10.1158/2643-3249.aml23-a38","DOIUrl":"https://doi.org/10.1158/2643-3249.aml23-a38","url":null,"abstract":"\u0000 Chronic Neutrophilic Leukemia (CNL) is a rare BCR-ABL negative myeloproliferative neoplasm that affects approximately 1 in a million individuals. The typical age of onset and disease presentation is in elderly patients with a median age of 63 and a range of 9-84. The oncogenic driver of CSF3R, the G-CSF receptor protein, in CNL has been classified over the last decade and has improved therapies for patients with targeted Tyrosine Kinase Inhibitors, such as Ruxolitinib (a potent JAK1/2 inhibitor). Currently, the only curative option is an allogeneic hemopoietic stem cell transplant with typical median overall survival of 2 years. Because of the low occurrence rate of CNL, there have only been 3 germline cases of CSF3R classified in literature. With these patients, they exhibit a lifelong skewing of the myeloid lineage causing gross neutrophilia. Our patient presented at 13 months with leukocytosis and neutrophilia, resulting in genetic testing revealing the diagnosis of the youngest documented case of CNL. A germline CSF3R T618I constitutive activating mutation was documented in our patient and in her father. Her father had documented lifelong leukocytosis of indeterminate origin and it was not until 33 that genetic testing was done, and he was diagnosed with CNL. He underwent an allogeneic stem cell transplant after being admitted with gross hepatosplenomegaly with a WBC of 322, the highest recorded in a germline CNL patient in literature. Our patient presented to clinic with leukocytosis ranging from 45-98 and hepatosplenomegaly. After a bone marrow aspirate and biopsy was taken to determine disease stage and severity, we immediately began Ruxolitinib therapy. We began 20 mg BID dosing based on platelets and monitored response to therapy while conducting targeted RNA-seq for myelodysplastic and myeloid leukemia genes on the bone marrow, which did not detect any secondary mutations. Ruxolitinib dosing was tapered down in a stepwise fashion, until the patient arrived at the current dose of 7.5 mg BID Ruxolitinib, resulting in stable leukocyte counts around 25. As part of monitoring, we are currently conducting 6-month BM procedures and NGS for AML/MDS genes and Ruxolitinib resistance mutations alongside monthly CBCs. Our patient has been on Ruxolitinib for 9 months and has not developed any secondary contributing mutations and remains sensitive to therapy. We continue to monitor our patient’s response to Ruxolitinib to determine if germline predisposition alters the transformative nature of the disease. Within T618I germline CNL cases, we are investigating the difference in phenotype and disease burden that we observe in our patient’s family compared to literature. Based on current cases, it seems that germline CNL does not transform during childhood and adolescence into AML without the influence of a secondary mutation. Retrospective studies into previous cases of CNL to determine if there is a higher frequency of germline origin could pave the","PeriodicalId":29944,"journal":{"name":"Blood Cancer Discovery","volume":"1 1","pages":""},"PeriodicalIF":11.2,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41457654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract A55: Role of ID2 in acute myeloid leukemia progression and resistance to chemotherapy","authors":"T. Sarkar, Jennifer Lombardo, Shweta Singh, K. Gudmundsson, Holly Morris, Shyam Saran, J. Keller","doi":"10.1158/2643-3249.aml23-a55","DOIUrl":"https://doi.org/10.1158/2643-3249.aml23-a55","url":null,"abstract":"\u0000 Acute myeloid leukemia (AML) is thought to be maintained by quiescent leukemia stem cells (LSCs), which are resistant to chemotherapy and responsible for relapse. Recent evidence suggests that a subset of LSCs with higher oxidative phosphorylation and/or increased senescence are responsible for resistance to chemotherapy and relapse. While several genes have been identified that are associated with the maintain LSC maintenance and promote resistance and relapse, the precious molecular mechanism(s) are currently not known. Inhibitor of DNA binding (ID) proteins are a group of Helix-Loop-Helix (HLH) transcription regulators, which function as dominant regulators of other HLH proteins (E proteins) that are required for normal hematopoietic, muscle, neuronal and other cell development. We found that loss of ID2 expression in murine hematopoietic cells results in activation, differentiation, and exhaustion of hematopoietic stem cells (HSCs). ID2 promotes quiescence by stabilizing HIF-1a expression. Analysis of TCGA data sets shows that high levels of ID2 expression is associated with reduced overall survival among AML patients, suggesting that ID2 may function to maintain LSCs. Similar to murine cells, knockdown (KD) of ID2 expression in human cord blood cells resulted in a loss of CD34+CD38− progenitors. Furthermore, knockdown of ID2 expression in the UT-7 AML cell line showed significantly reduced leukemogenic potential in NSG mice, suggesting that ID2 is required for AML cell growth in vivo. UT7-ID2-KD cell line shows significant reduction of colony number when cultured in low oxygen condition in vitro, suggesting a potential role of HIF protein. In comparison, overexpression (OE) of ID2 in the human AML cell line, MO7e, promotes their leukemic potential and burden in NSG mice in vivo, suggesting that ID2 may function to preserve LSC quiescence. Initial studies in primary AML-PDX cells showed reduced leukemic potential upon ID2 knock down. High level of ID2 expression is associated with poor chemotherapy response in patients. We found that MO7e-ID2-OE are resistance to Cytarabine (AraC), while UT7-ID2-KD are susceptible to AraC. Furthermore, we found that AML cell lines that survive AraC treatment show increased ID2 expression, suggesting that ID2 may promote survival of chemotherapy resistant AML cells. It has been reported that AraC resistance of AML cells is associated with increased senescence. We found that surviving UT7-ID2-KD cells after AraC treatment have significantly reduced senescence population compared to controls. Taken together, ID2 promotes normal murine and human HSC quiescence, and may function promote LSC maintenance and resistance to chemotherapy.\u0000 Citation Format: Tanmoy Sarkar, Jennifer Lombardo, Shweta Singh, Kristbjorn O Gudmundsson, Holly M Morris, Shyam Saran, Jonathan R Keller. Role of ID2 in acute myeloid leukemia progression and resistance to chemotherapy [abstract]. In: Proceedings of the AACR Special Conference: Ac","PeriodicalId":29944,"journal":{"name":"Blood Cancer Discovery","volume":" ","pages":""},"PeriodicalIF":11.2,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48812548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}