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Supplementary Figure S1 shows enrichment of FBL in LSC, correlation of FBL with LSC signature and rRNA 2'-O-Me in healthy hematopoietic cells. Supplementary Figure S2 shows the association of rRNA 2’-O-Me with LSC and hematopoietic differentiation signatures. Supplementary Figure S3 shows strategy for LSC sorting and distribution of LSC methylation sites on ribosomes. Supplementary Figure S4 shows the effect of FBL knockdown on rRNA 2’-O-methylation and in vitro proliferation of leukemia cells. Supplementary Figure S5 show the effect of FBL overexpression on in vivo engraftment of primary AML cells. Supplementary Figure S6 shows the effect of FBL knockdown on nascent proteome and metabolism of AML cells. Supplementary Figure S7 shows the ribosome footprinting analysis after FBL knockdown. Supplementary Figure S8 shows the association of Gm1447 with LSC signature and the effect of Gm1447 supression on cellular amino acid levels. Supplementary Figure S9 shows regulatory effect of Gm1447 on in vivo leukemic self-renewal.

The development and regulation of malignant self-renewal remain unresolved issues. Here, we provide biochemical, genetic, and functional evidence that dynamics in ribosomal RNA (rRNA) 2′-O-methylation regulate leukemia stem cell (LSC) activity in vivo. A comprehensive analysis of the rRNA 2′-O-methylation landscape of 94 patients with acute myeloid leukemia (AML) revealed dynamic 2′-O-methylation specifically at exterior sites of ribosomes. The rRNA 2′-O-methylation pattern is closely associated with AML development stage and LSC gene expression signature. Forced expression of the 2′-O-methyltransferase fibrillarin (FBL) induced an AML stem cell phenotype and enabled engraftment of non-LSC leukemia cells in NSG mice. Enhanced 2′-O-methylation redirected the ribosome translation program toward amino acid transporter mRNAs enriched in optimal codons and subsequently increased intracellular amino acid levels. Methylation at the single site 18S-guanosine 1447 was instrumental for LSC activity. Collectively, our work demonstrates that dynamic 2′-O-methylation at specific sites on rRNAs shifts translational preferences and controls AML LSC self-renewal.Significance:We establish the complete rRNA 2′-O-methylation landscape in human AML. Plasticity of rRNA 2′-O-methylation shifts protein translation toward an LSC phenotype. This dynamic process constitutes a novel concept of how cancers reprogram cell fate and function.This article is highlighted in the In This Issue feature, p. 247

Supplementary table S1 shows all rRNA 2’-O-methylation sites identified in human AMLs. Supplementary table S2 shows dynamic rRNA 2’-O-methylation sites in each DyMeC cluster. Supplementary table S3 shows the location of rRNA 2’-O-methylation static sites in ribosome regions. Supplementary table S4 shows proteins with altered translation after FBL knockdown.

We retrospectively analysed all German inpatient cases of haemophagocytic lymphohistiocytosis (HLH) from 2014 to 2020 to describe the epidemiology, clinical course, and underlying diseases of 4065 HLH patients. The age-standardized incidence rate of HLH in Germany was 0.52/100 000 people in 2014 and steadily increased by 10% per year to 0.97/100 000 in 2020 (mean 0.70/100 000). Inpatient deaths related to HLH increased from 0.84/1 000 000 people in 2014 to 2.32/1 000 000 people in 2020, caused by rising numbers of older HLH patients. Overall, HLH is more frequent than previously expected and incidence as well as HLH-related deaths increased significantly.

Higher doses of cytarabine appear to improve long-term outcome in acute myeloid leukemia (AML), in particular for younger patients. To this end, the optimal dosage of single agent cytarabine in consolidation therapy remains elusive. Here, we assessed the impact of different dosages of cytarabine consolidation after 7 + 3 induction on outcome in a large real-world data set from the German Study Alliance Leukemia-Acute Myeloid Leukemia (SAL-AML) registry. Patients below 65 years of age, registered between April 2005 and September 2020, who attained complete remission after intensive induction and received at least one consolidation cycle with intermediate (IDAC) or high dose cytarabine (HiDAC) were selected. To account for differences in patient and disease characteristics between both groups, the average treatment effect was estimated by propensity score weighting. Six-hundred-forty-two patients received HiDAC consolidation with median dosage of median 17.6 (IQR, 16.5–18.0) g/m² for a median number of 3 cycles (IQR, 2–3), whereas 178 patients received IDAC consolidation with 5.9 (IQR, 5.7–8.6) g/m² for a median of 2 cycles (IQR, 1–3). Both groups differed significantly in some important characteristics (age, sex, cytogenetic risk group, ECOG performance status, disease status, HCT-CI, number of induction cycles). After propensity score weighting for differences in patient and disease characteristics, relapse-free survival after 2 years was comparable between HiDAC-treated (55.3%) and IDAC-treated (55.6%) patients. Moreover, no significant differences in overall survival were observed after 2 years (84.7 vs. 80.6%). Notably, more patients treated with IDAC received allogeneic hematopoietic cell transplantation in first remission (37.6 vs. 19.8%, p

The processes leading from disturbed B cell development to adult B cell progenitor acute lymphoblastic leukemia (BCP-ALL) are poorly understood. Here, we describe Irf4−/− mice as prone to developing BCP-ALL with age. Irf4−/− preB-I cells exhibited impaired differentiation but enhanced proliferation in response to IL-7, along with reduced retention in the IL-7 providing bone marrow niche due to decreased CXCL12 responsiveness. Thus selected, preB-I cells acquired Jak3 mutations, probably following irregular AID activity, resulting in malignant transformation. We demonstrate heightened IL-7 sensitivity due to Jak3 mutants, devise a model to explain it and describe structural and functional similarities to Jak2 mutations often occurring in human Ph-like ALL. Finally, targeting JAK signaling with Ruxolitinib in vivo prolonged survival of mice bearing established Irf4−/− leukemia. Intriguingly, organ infiltration including leukemic meningeosis was selectively reduced without affecting blood blast counts. In this work, we present spontaneous leukemogenesis following IRF4 deficiency with potential implications for high-risk BCP-ALL in adult humans.

Idiopathic Environmental Intolerance (IEI) has been associated with psychogenic factors and an increased number of comorbid psychiatric disorders such as depression and anxiety disorder. The purpose of the current study was to examine a possible overlap of psychological and somatic symptoms between subjects with IEI and patients with major depression and schizophrenia as well as to specify characteristic differences. The different symptom clusters included symptoms of chemical intolerance, neurotoxicity and psychological distress as well as measurements of mental health such as anxiety, depression, somatoform symptoms, and schizophrenia-specific disturbances in cognitive domains. IEI patients reported higher overall levels in physical symptoms such as chemical intolerance, neurotoxicity and somatic symptoms not attributable to an organic cause. Schizophrenia patients showed higher overall levels in self-experienced disturbances in several schizophrenia-specific cognitive domains, whereas general psychological distress, anxiety and depression were rated highest by patients with major depression. Importantly, the groups markedly differed in the shapes of profiles of various symptom clusters. Our results provide evidence that IEI patients can be distinguished on the phenomenological level from patients with major depression or schizophrenia, and that distinct domains of psychological and somatic symptoms are particularly problematic in specific diagnostic groups.

In order to assess any correlation between MDR-1 expression and chromosomal aberrations, and to define their impact on clinical outcome in newly diagnosed AML pts, we investigated bone marrow and peripheral blood samples of 49 consecutive pts admitted to our hospital. Monosomy 7, trisomy 8 and 5q- were evaluated by means of interphase fluorescence in situ hybridization (FISH). Monosomy 7 was present in 6 pts, trisomy 8 in 5 pts, and 5q- in 6 pts. More than one aberration was seen in 7 pts. Chromosomal aberrations were mostly found in older pts (12/14 >60 years; p=0.03) and in pts with CD34 positive leukemic blasts (13/14 coexpressed CD34, p=0.0004). In 25 pts also standard G-banding analysis was performed leading to concordant results regarding chromosomes 7, 8 and 5. Flow cytometry identifyed MDR-1 positivity (MDR+) in 16 pts. MDR-1 expression appeared to be a characteristic feature in CD34+ AML (12/16 were CD34+ and MDR+ pts; p=0.013). No correlation, however, was found between chromosomal aberrations and MDR-1 expression. Pts with aberrations of either chromosomes 7, 8 or 5 detected by FISH (FISH+) were predominantly resistant to induction therapy (6/8 pts, p=0.004). A lower rate of complete remission (CR) was also seen in pts with MDR-1 expression (p=0.006). MDR+/FISH+ pts (n=3) were all refractory to remission induction, while all MDR-/FISH- pts (n=19) achieved CR (p=0.0006). MDR-1+ as well as pts with aberrations of chromosomes 7, and 5(q) showed a significantly decreased probability of overall survival. In conclusion, MDR-1 expression as well as abnormalities of chromosomes 7, and 5(q) predict poor clinical outcome in AML. The identification of these prognostic factors provides useful information for risk adapted treatment strategies.