Browsing by Subject "Acute Myeloid Leukemia"

Now showing 1 - 7 of 7
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    Acute Myeloid Leukemia: The Aga Khan Experience
    (Association of Kenya Physicians, 2007) Ngunga, Mzee; Association of Kenya Physicians Scientific Conference (11th : Mar. 2007 : Eldoret, Kenya)
    AML is characterized by an increase in the number of myeloid cells in the marrow and an arrest in their maturation.
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    Clinical features and outcomes of patients with Shwachman-Diamond syndrome and myelodysplastic syndrome or acute myeloid leukaemia: a multicentre, retrospective, cohort study
    (Elsevier, 2020-03) Myers, Kasiani C.; Furutani, Elissa; Weller, Edie; Siegele, Bradford; Galvin, Ashley; Arsenault, Valerie; Alter, Blanche P.; Boulad, Farid; Bueso-Ramos, Carlos; Burroughs, Lauri; Castillo, Paul; Connelly, James; Davies, Stella M.; DiNardo, Courtney D.; Hanif, Iftikhar; Ho, Richard H.; Karras, Nicole; Manalang, Michelle; McReynolds, Lisa J.; Nakano, Taizo A.; Nalepa, Grzegorz; Norkin, Maxim; Oberley, Matthew J.; Orgel, Etan; Pastore, Yves D.; Rosenthal, Joseph; Walkovich, Kelly; Larson, Jordan; Malsch, Maggie; Elghetany, M. Tarek; Fleming, Mark D.; Shimamura, Akiko; Pediatrics, School of Medicine
    Background: Data to inform surveillance and treatment for leukaemia predisposition syndromes are scarce and recommendations are largely based on expert opinion. This study aimed to investigate the clinical features and outcomes of patients with myelodysplastic syndrome or acute myeloid leukaemia and Shwachman-Diamond syndrome, an inherited bone marrow failure disorder with high risk of developing myeloid malignancies. Methods: We did a multicentre, retrospective, cohort study in collaboration with the North American Shwachman-Diamond Syndrome Registry. We reviewed patient medical records from 17 centres in the USA and Canada. Patients with a genetic (biallelic mutations in the SBDS gene) or clinical diagnosis (cytopenias and pancreatic dysfunction) of Shwachman-Diamond syndrome who developed myelodysplastic syndrome or acute myeloid leukaemia were eligible without additional restriction. Medical records were reviewed between March 1, 2001, and Oct 5, 2017. Masked central review of bone marrow pathology was done if available to confirm leukaemia or myelodysplastic syndrome diagnosis. We describe the clinical features and overall survival of these patients. Findings: We initially identified 37 patients with Shwachman-Diamond syndrome and myelodysplastic syndrome or acute myeloid leukaemia. 27 patients had samples available for central pathology review and were reclassified accordingly (central diagnosis concurred with local in 15 [56%] cases), 10 had no samples available and were classified based on the local review data, and 1 patient was excluded at this stage as not eligible. 36 patients were included in the analysis, of whom 10 (28%) initially presented with acute myeloid leukaemia and 26 (72%) initially presented with myelodysplastic syndrome. With a median follow-up of 4·9 years (IQR 3·9-8·4), median overall survival for patients with myelodysplastic syndrome was 7·7 years (95% CI 0·8-not reached) and 0·99 years (95% CI 0·2-2·4) for patients with acute myeloid leukaemia. Overall survival at 3 years was 11% (95% CI 1-39) for patients with leukaemia and 51% (29-68) for patients with myelodysplastic syndrome. Management and surveillance were variable. 18 (69%) of 26 patients with myelodysplastic syndrome received upfront therapy (14 haematopoietic stem cell transplantation and 4 chemotherapy), 4 (15%) patients received no treatment, 2 (8%) had unavailable data, and 2 (8%) progressed to acute myeloid leukaemia before receiving treatment. 12 patients received treatment for acute myeloid leukaemia-including the two patients initially diagnosed with myelodysplastic who progressed- two (16%) received HSCT as initial therapy and ten (83%) received chemotherapy with intent to proceed with HSCT. 33 (92%) of 36 patients (eight of ten with leukaemia and 25 of 26 with myelodysplastic syndrome) were known to have Shwachman-Diamond syndrome before development of a myeloid malignancy and could have been monitored with bone marrow surveillance. Bone marrow surveillance before myeloid malignancy diagnosis was done in three (33%) of nine patients with leukaemia for whom surveillance status was confirmed and 11 (46%) of 24 patients with myelodysplastic syndrome. Patients monitored had a 3-year overall survival of 62% (95% CI 32-82; n=14) compared with 28% (95% CI 10-50; n=19; p=0·13) without surveillance. Six (40%) of 15 patients with available longitudinal data developed myelodysplastic syndrome in the setting of stable blood counts. Interpretation: Our results suggest that prognosis is poor for patients with Shwachman-Diamond syndrome and myelodysplastic syndrome or acute myeloid leukaemia owing to both therapy-resistant disease and treatment-related toxicities. Improved surveillance algorithms and risk stratification tools, studies of clonal evolution, and prospective trials are needed to inform effective prevention and treatment strategies for leukaemia predisposition in patients with Shwachman-Diamond syndrome.
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    DNA Damage On The DOCK In FLT3-ITD-Driven Acute Myeloid Leukemia
    (Ferrata Storti Foundation, 2019-12) Pandey, Ruchi; Kapur, Reuben; Pediatrics, School of Medicine
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    Internal Tandem Duplication in FLT3 Attenuates Proliferation and Regulates Resistance to the FLT3 Inhibitor AC220 by Modulating p21Cdkn1a and Pbx1 in Hematopoietic Cells
    (Public Library of Science (PLoS), 2016) Abe, Mariko; Pelus, Louis M.; Singh, Pratibha; Hirade, Tomohiro; Onishi, Chie; Purevsuren, Jamiyan; Taketani, Takeshi; Yamaguchi, Seiji; Fukuda, Seiji; Department of Microbiology and Immunology, IU School of Medicine
    Internal tandem duplication (ITD) mutations in the Fms-related tyrosine kinase 3 (FLT3) gene (FLT3-ITD) are associated with poor prognosis in patients with acute myeloid leukemia (AML). Due to the development of drug resistance, few FLT3-ITD inhibitors are effective against FLT3-ITD+ AML. In this study, we show that FLT3-ITD activates a novel pathway involving p21Cdkn1a (p21) and pre-B cell leukemia transcription factor 1 (Pbx1) that attenuates FLT3-ITD cell proliferation and is involved in the development of drug resistance. FLT3-ITD up-regulated p21 expression in both mouse bone marrow c-kit+-Sca-1+-Lin- (KSL) cells and Ba/F3 cells. The loss of p21 expression enhanced growth factor-independent proliferation and sensitivity to cytarabine as a consequence of concomitantly enriching the S+G2/M phase population and significantly increasing the expression of Pbx1, but not Evi-1, in FLT3-ITD+ cells. This enhanced cell proliferation following the loss of p21 was partially abrogated when Pbx1 expression was silenced in FLT3-ITD+ primary bone marrow colony-forming cells and Ba/F3 cells. When FLT3-ITD was antagonized with AC220, a selective inhibitor of FLT3-ITD, p21 expression was decreased coincident with Pbx1 mRNA up-regulation and a rapid decline in the number of viable FLT3-ITD+ Ba/F3 cells; however, the cells eventually became refractory to AC220. Overexpressing p21 in FLT3-ITD+ Ba/F3 cells delayed the emergence of cells that were refractory to AC220, whereas p21 silencing accelerated their development. These data indicate that FLT3-ITD is capable of inhibiting FLT3-ITD+ cell proliferation through the p21/Pbx1 axis and that treatments that antagonize FLT3-ITD contribute to the subsequent development of cells that are refractory to a FLT3-ITD inhibitor by disrupting p21 expression.
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    Outcomes of Pediatric Patients with Therapy-Related Myeloid Neoplasms
    (Springer Nature, 2021) Sharma, Akshay; Huang, Sujuan; Li, Ying; Brooke, Russell J.; Ahmed, Ibrahim; Allewelt, Heather B.; Amrolia, Persis; Bertaina, Alice; Bhatt, Neel S.; Bierings, Marc B.; Bies, Joshua; Brisset, Claire; Brondon, Jennifer E.; Dahlberg, Ann; Dalle, Jean-Hugues; Eissa, Hesham; Fahd, Mony; Gassas, Adam; Gloude, Nicholas J.; Goebel, W. Scott; Goeckerman, Erika S.; Harris, Katherine; Ho, Richard; Hudspeth, Michelle P.; Huo, Jeffrey S.; Jacobsohn, David; Kasow, Kimberly A.; Katsanis, Emmanuel; Kaviany, Saara; Keating, Amy K.; Kernan, Nancy A.; Ktena, Yiouli P.; Lauhan, Colette R.; López-Hernandez, Gerardo; Martin, Paul L.; Myers, Kasiani C.; Naik, Swati; Olaya-Vargas, Alberto; Onishi, Toshihiro; Radhi, Mohamed; Ramachandran, Shanti; Ramos, Kristie; Rangarajan, Hemalatha G.; Roehrs, Philip A.; Sampson, Megan E.; Shaw, Peter J.; Skiles, Jodi L.; Somers, Katherine; Symons, Heather J.; de Tersant, Marie; Uber, Allison N.; Versluys, Birgitta; Cheng, Cheng; Triplett, Brandon M.; Pediatrics, School of Medicine
    Long-term outcomes after allogeneic hematopoietic cell transplantation (HCT) for therapy-related myeloid neoplasms (tMNs) are dismal. There are few multicenter studies defining prognostic factors in pediatric patients with tMNs. We have accumulated the largest cohort of pediatric patients who have undergone HCT for a tMN to perform a multivariate analysis defining factors predictive of long-term survival. Sixty-eight percent of the 401 patients underwent HCT using a myeloablative conditioning (MAC) regimen, but there were no statistically significant differences in the overall survival (OS), event-free survival (EFS), or cumulative incidence of relapse and non-relapse mortality based on the conditioning intensity. Among the recipients of MAC regimens, 38.4% of deaths were from treatment-related causes, especially acute graft versus host disease (GVHD) and end-organ failure, as compared to only 20.9% of deaths in the reduced-intensity conditioning (RIC) cohort. Exposure to total body irradiation (TBI) during conditioning and experiencing grade III/IV acute GVHD was associated with worse OS. In addition, a diagnosis of therapy-related myelodysplastic syndrome and having a structurally complex karyotype at tMN diagnosis were associated with worse EFS. Reduced-toxicity (but not reduced-intensity) regimens might help to decrease relapse while limiting mortality associated with TBI-based HCT conditioning in pediatric patients with tMNs.
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    Primary Myeloid Sarcoma of the Prostate: A Case Report and Literature Review
    (Hindawi, 2018-04-29) Nguyen, Ryan; Sayar, Hamid; Medicine, School of Medicine
    We report the case of a 73-year-old male with primary myeloid sarcoma (MS) of the prostate. He underwent remission-induction chemotherapy followed by conventional consolidation for acute myeloid leukemia (AML). One year after initial diagnosis, he was without evidence of AML, the longest reported period of time in the literature for a case of primary MS of the prostate. From 1985 to 2017, fifteen other cases of MS of the prostate have been reported and are reviewed here. Five cases occurred as primary MS, without evidence of AML on bone marrow examination or prior history of hematologic disorders, and progressed to AML within a range of three weeks to seven months. None of these cases were started on conventional chemotherapy for AML prior to progression. Due to its rarity, primary MS of the prostate is often diagnosed incidentally, but prompt AML-targeted treatment is crucial to delaying the progression to AML.
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    Role of S6K1 in regulating self-renewal of hematopoietic stem cells and propagatoin of leukemia
    (2015-12-15) Ghosh, Joydeep; Kapur, Reuben; Carlesso, Nadia; Pelus, Louis M.; Srour, Edward F.
    The development and function of hematopoietic stem cells (HSCs) is regulated by numerous signaling pathways including Akt-mechanistic target of rapamycin complex1 (mTORC1) pathway. Dysregulation of this pathway results in impaired HSC function and contributes to the development of hematologic malignancies. Activated mTORC1 phosphorylates and subsequently activates ribosomal protein S6 kinase 1 (S6K1). To study the role of S6K1 in hematopoiesis as well as leukemogenesis, we used a genetic model of S6K1 deficient mice (S6K1-/-). We found that loss of S6K1 expression in HSCs results in reduction of absolute HSC number in bone marrow (BM). Following chemotherapy, cycling HSCs undergo apoptosis and quiescent HSCs are required to cycle to regenerate the hematopoietic system. S6K1 regulates the quiescence of HSCs and in the absence of S6K1, mice are more susceptible to repeated myeloablative stress. We also observed that loss of expression as well as gain of expression of S6K1 affects the self-renewal ability of HSCs. Interestingly, when we overexpressed S6K1, it also resulted in reduced self-renewal of HSCs. Next, we assessed the role of S6K1 in the propagation of acute myeloid leukemia (AML). The mixed-lineage leukemia (MLL) gene is required for the maintenance of adult HSCs. Translocations in MLL are detected in approximately 5-10% of adult acute leukemia patients and in approximately 70% of acute leukemias in infants. We expressed MLL-AF9 fusion oncoprotein in WT and S6K1-/- hematopoietic stem and progenitor cells (HSC/Ps) and performed serial transplantation. Upon secondary transplantation, recipients of S6K1 deficient AML cells survived significantly longer compared to controls. In vitro, pharmacological inhibition of S6K1 activity resulted in reduced growth of primary human cells expressing MLL-AF9. Both human and murine HSC/Ps expressing MLL-AF9 showed reduced mTORC1 activity upon inhibition of S6K1 suggesting that loss of S6K1 activity results in reduced Akt-mTORC1 activation both upstream and downstream of mTORC1. Overall, our studies establish a critical role of S6K1 activity in the maintenance of HSC function and in the propagation of leukemia.