Targeting Telomere Biology in Acute Lymphoblastic Leukemia.

Increased cell proliferation is a hallmark of acute lymphoblastic leukemia (ALL), and genetic alterations driving clonal proliferation have been identified as prognostic factors. To evaluate replicative history and its potential prognostic value, we determined telomere length (TL) in lymphoblasts, B-, and T-lymphocytes, and measured telomerase activity (TA) in leukocytes of patients with ALL. In addition, we evaluated the potential to suppress the in vitro growth of B-ALL cells by the telomerase inhibitor imetelstat. We found a significantly lower TL in lymphoblasts (4.3 kb in pediatric and 2.3 kb in adult patients with ALL) compared to B- and T-lymphocytes (8.0 kb and 8.2 kb in pediatric, and 6.4 kb and 5.5 kb in adult patients with ALL). TA in leukocytes was 3.2 TA/C for pediatric and 0.7 TA/C for adult patients. Notably, patients with high-risk pediatric ALL had a significantly higher TA of 6.6 TA/C compared to non-high-risk patients with 2.2 TA/C. The inhibition of telomerase with imetelstat ex vivo led to significant dose-dependent apoptosis of B-ALL cells. These results suggest that TL reflects clonal expansion and indicate that elevated TA correlates with high-risk pediatric ALL. In addition, telomerase inhibition induces apoptosis of B-ALL cells cultured in vitro. TL and TA might complement established markers for the identification of patients with high-risk ALL. Moreover, TA seems to be an effective therapeutic target; hence, telomerase inhibitors, such as imetelstat, may augment standard ALL treatment

Longitudinal cytokine profiling identifies GRO-α and EGF as potential biomarkers of disease progression in Essential Thrombocythemia

Myeloproliferative neoplasms (MPNs) are characterized by deregulation of mature blood cell production and increased risk of myelofibrosis (MF) and leukemic transformation. Numerous driver mutations have been identified but substantial disease heterogeneity remains unexplained, implying the involvement of additional as yet unidentified factors. The inflammatory microenvironment has recently attracted attention as a crucial factor in MPN biology, in particular whether inflammatory cytokines and chemokines contribute to disease establishment or progression. Here we present a large-scale study of serum cytokine profiles in more than 400 MPN patients and identify an essential thrombocythemia (ET)-specific inflammatory cytokine signature consisting of Eotaxin, GRO-α, and EGF. Levels of 2 of these markers (GRO-α and EGF) in ET patients were associated with disease transformation in initial sample collection (GRO-α) or longitudinal sampling (EGF). In ET patients with extensive genomic profiling data (n = 183) cytokine levels added significant prognostic value for predicting transformation from ET to MF. Furthermore, CD56+CD14+ pro-inflammatory monocytes were identified as a novel source of increased GRO-α levels. These data implicate the immune cell microenvironment as a significant player in ET disease evolution and illustrate the utility of cytokines as potential biomarkers for reaching beyond genomic classification for disease stratification and monitoring.The serum cytokine studies were supported by a research grant from the Rosetrees Trust. NFØ was supported by grants from the Danish Lundbeck Foundation and Danish Cancer Society, J.G. was supported by fellowships from Bloodwise and the Kay Kendall Leukaemia Fund; and M.S.S. is the recipient of a Biotechnology and Biological Sciences Research Council Industrial Collaborative Awards in Science and Engineering PhD Studentship. Work in the R.C.S. laboratory was supported by grants from the Stiftung Blutspendezentrum SRK beider Basel, the Swiss National Science Foundation (31003A-147016/1 and 31003A_166613), and the Swiss Cancer League (KLS-2950-02-2012 and KFS-3655-02-2015). A.K. was supported by the Else Kröner-Fresenius Foundation. Work in the A.R.G. laboratory is supported by the Wellcome Trust, Bloodwise, Cancer Research UK, the Kay Kendall Leukaemia Fund, and the Leukemia and Lymphoma Society of America. Work in the D.G.K. laboratory is supported by a Bloodwise Bennett Fellowship (15008), a European Hematology Association Non-Clinical Advanced Research Fellowship, and an ERC Starting Grant (ERC-2016-STG–715371). D.G.K. and A.R.G. are supported by a core support grant from the Wellcome Trust and Medical Research Council to the Wellcome MRC Cambridge Stem Cell Institute, the National Institute for Health Research Cambridge Biomedical Research Centre, and the CRUK Cambridge Cancer Centre

Longitudinal Cytokine Profiling Identifies GRO-α and EGF as Potential Biomarkers of Disease Progression in Essential Thrombocythemia.

Myeloproliferative neoplasms (MPNs) are characterized by deregulation of mature blood cell production and increased risk of myelofibrosis (MF) and leukemic transformation. Numerous driver mutations have been identified but substantial disease heterogeneity remains unexplained, implying the involvement of additional as yet unidentified factors. The inflammatory microenvironment has recently attracted attention as a crucial factor in MPN biology, in particular whether inflammatory cytokines and chemokines contribute to disease establishment or progression. Here we present a large-scale study of serum cytokine profiles in more than 400 MPN patients and identify an essential thrombocythemia (ET)-specific inflammatory cytokine signature consisting of Eotaxin, GRO-α, and EGF. Levels of 2 of these markers (GRO-α and EGF) in ET patients were associated with disease transformation in initial sample collection (GRO-α) or longitudinal sampling (EGF). In ET patients with extensive genomic profiling data (n = 183) cytokine levels added significant prognostic value for predicting transformation from ET to MF. Furthermore, CD56+CD14+ pro-inflammatory monocytes were identified as a novel source of increased GRO-α levels. These data implicate the immune cell microenvironment as a significant player in ET disease evolution and illustrate the utility of cytokines as potential biomarkers for reaching beyond genomic classification for disease stratification and monitoring.The serum cytokine studies were supported by a research grant from the Rosetrees Trust. NFØ was supported by grants from the Danish Lundbeck Foundation and Danish Cancer Society, J.G. was supported by fellowships from Bloodwise and the Kay Kendall Leukaemia Fund; and M.S.S. is the recipient of a Biotechnology and Biological Sciences Research Council Industrial Collaborative Awards in Science and Engineering PhD Studentship. Work in the R.C.S. laboratory was supported by grants from the Stiftung Blutspendezentrum SRK beider Basel, the Swiss National Science Foundation (31003A-147016/1 and 31003A_166613), and the Swiss Cancer League (KLS-2950-02-2012 and KFS-3655-02-2015). A.K. was supported by the Else Kröner-Fresenius Foundation. Work in the A.R.G. laboratory is supported by the Wellcome Trust, Bloodwise, Cancer Research UK, the Kay Kendall Leukaemia Fund, and the Leukemia and Lymphoma Society of America. Work in the D.G.K. laboratory is supported by a Bloodwise Bennett Fellowship (15008), a European Hematology Association Non-Clinical Advanced Research Fellowship, and an ERC Starting Grant (ERC-2016-STG–715371). D.G.K. and A.R.G. are supported by a core support grant from the Wellcome Trust and Medical Research Council to the Wellcome MRC Cambridge Stem Cell Institute, the National Institute for Health Research Cambridge Biomedical Research Centre, and the CRUK Cambridge Cancer Centre

Hb G-Waimanalo [A1] [α64(E13)Asp→Asn; HBA1: c.193 G > A] with Decreased Oxygen Affinity

A clinically asymptomatic 12-year-old girl showed microcytosis in routine examination. Cation exchange high performance liquid chromatography (HPLC), revealed two additional peaks eluting after Hb A and DNA sequencing uncovered a novel heterozygous mutation at codon 64 of the α1-globin gene. The hemoglobin (Hb) variant was annotated as Hb G-Waimanalo [A1]. Further analyses demonstrated a decreased oxygen affinity Hb compared to the normal Hb configuration

Fulminant Essential Thrombocythemia Associated with Acquired Von Willebrand Syndrome and Bleeding Episodes in a 14-year-old Girl.

BACKGROUND  Essential thrombocythemia is a chronic myeloproliferative neoplasm. It is extremely rare in children below 15 years of age with an estimated annual incidence of only 0.09 per million. Usually, clinical symptoms associated with essential thrombocythemia are mild or absent. CASE  Here, we present the case of a 14-year-old female patient fulminantly presenting with acute symptoms comprising visual impairment, palmar and plantar stabbing pain. Blood count revealed massive thrombocytosis of 2373 × 109/L. Bone marrow morphology showed elevated numbers of mature megakaryocytes. Von Willebrand factor activity/antigen ratio was significantly reduced compatible with an acquired Von Willebrand syndrome associated with high platelet counts. Molecular analyses for driver mutations of myeloproliferative neoplasms including JAK2V617F, CALR and MPL were negative. Acute therapy comprising hyperhydration and oxygen supply complemented by acetylsalicylic acid led to amelioration of symptoms. Medication with hydroxycarbamide maintained a significant reduction of platelet counts but had to be reduced or withheld several times due to neutropenia. Repeated bleeding episodes observed in the course were clearly associated with increases in platelet counts above 1200 × 109/L explained by acquired von Willebrand syndrome. Sixteen months after diagnosis, therapy was switched to pegylated interferon and platelet counts could be stabilized without significant side effects

Loss of Stat1 decreases megakaryopoiesis and favors erythropoiesis in a JAK2-V617F-driven mouse model of MPNs

The interferon-gamma (IFNgamma)/signal transducer and activator of transcription 1 (Stat1) pathway shows higher activity in patients with essential thrombocythemia (ET) than in polycythemia vera (PV) and was proposed to be promoting the ET phenotype. We explored the phenotypic consequences of Stat1 deficiency on the effects of Janus kinase 2 (JAK2)-V617F in vivo by crossing mice expressing JAK2-V617F with Stat1 knockout mice. JAK2-V617F;Stat1(-/-) double transgenic mice showed higher red cell parameters and lower platelet counts compared with JAK2-V617F;Stat1(+/+) mice. Bone marrow transplantation reproduced these phenotypic changes in wild-type recipients, demonstrating that the effect of Stat1 is cell-intrinsic and does not require a Stat1-deficient microenvironment. Deletion of Stat1 increased burst-forming unit-erythroid and reduced colony-forming unit-megakaryocyte colony formation driven by JAK2-V617F, but was not sufficient to completely normalize the platelet count. Gata1, a key regulator of megakaryopoiesis and erythropoiesis, was decreased in Stat1-deficient platelets. V617F transgenic mice with thrombocytosis had higher serum levels of IFNgamma than normal controls and patients with ET showed higher IFNgamma serum levels than patients with PV. Together, these results support the concept that activating Stat1 in the presence of JAK2-V617F, for example, through IFNgamma, constrains erythroid differentiation and promotes megakaryocytic development, resulting in ET phenotype

Hearing loss and quality of life in survivors of paediatric CNS tumours and other cancers.

Hearing loss, a complication of cancer treatment, may reduce health-related quality of life (HRQoL), especially in childhood cancer survivors of central nervous system (CNS) tumours who often have multiple late effects. We examined the effect of hearing loss on HRQoL in young survivors of CNS and other childhood cancers. Within the Swiss Childhood Cancer Survivor Study, we sent questionnaires about hearing loss and HRQoL (KIDSCREEN-27) to parents of survivors aged 8-15 years. We stratified the effect of hearing loss on HRQoL by cancer diagnosis, using multivariable logistic regression and adjusting for sociodemographic and clinical factors. Hearing loss was associated with impaired physical well-being [unadjusted estimated differences - 4.6 (CI - 9.2, - 0.1); adjusted - 4.0 (CI - 7.6, - 0.3)] and peers and social support [unadjusted - 6.7 (CI - 13.0, - 0.3); adjusted - 5.0 (CI - 10.5, 0.9)] scores in survivors of CNS tumours (n = 123), but not in children diagnosed with other cancers (all p-values > 0.20, n = 577). Clinicians should be alert to signs of reduced physical well-being and impaired relationships with peers. Especially survivors of CNS tumours may benefit most from strict audiological monitoring and timely intervention to mitigate secondary consequences of hearing loss on HRQoL