Tumor necrosis factor and lymphotoxin-alpha genetic polymorphisms and risk of relapse in childhood B-cell precursor acute lymphoblastic leukemia: a case-control study of patients treated with BFM therapy

BACKGROUND: Circulating levels of tumor necrosis factor (TNF) and lymphotoxin-α (LT-α) have been associated with outcome in solid and hematologic malignancies. Within the TNF gene and the LT-α gene, polymorphisms have been identified at nucleotide positions -308 and +252, respectively. The variant alleles for TNF are designated TNF1 and TNF2, the ones for LT-α LT-α (10.5 kb) and LT-α (5.5 kb). Of interest, TNF2 and LT-α (5.5 kb) were shown to be associated with higher TNF and LT-α plasma levels than their counterparts. In the present study, we investigated the associations of the above mentioned polymorphisms with risk of relapse in childhood acute lymphoblastic leukemia (ALL) treated according to Berlin-Frankfurt-Münster (BFM) protocols. METHODS: Matched case-control study of 64 relapsed and 64 successfully treated non-relapsed childhood B-cell precursor ALL patients of standard and intermediate risk for treatment failure. RESULTS: The odds ratio (OR) for the combined category of TNF1/TNF2 and TNF2/TNF2 genotypes in comparison to the TNF1/TNF1 genotype was 1.17 (95 % confidence interval (CI) = 0.53 - 2.56, P = 0.697). The ORs for the LT-α (10.5 kb/5.5 kb) and the LT-α (5.5 kb/5.5 kb) genotypes with reference to the LT-α (10.5 kb/10.5 kb) genotype were 2.17 (95 % CI = 0.84 - 5.58, P = 0.107) and 0.5 (95 % CI = 0.09 - 2.66, P = 0.418), respectively. CONCLUSIONS: Our results do not suggest a major role of the investigated genetic polymorphisms with regard to risk of relapse in standard- and intermediate-risk childhood B-cell precursor ALL treated according to BFM protocols

Über die Brüderlichkeit: Rede eines demokratischen Hofnarren an ein bürgerliches Publikum

Kaufmann F-X. Über die Brüderlichkeit: Rede eines demokratischen Hofnarren an ein bürgerliches Publikum. In: Rahner K, Welte B, eds. Mut zur Tugend: über die Fähigkeit, menschlicher zu leben. Taschenbuch . Vol 1986. Freiburg im Breisgau: Herder; 1979: 67-71

Mutations in the gene for the granulocyte colony-stimulating-factor receptor in patients with acute myeloid leukemia preceded by severe congenital neutropenia

BACKGROUND. In severe congenital neutropenia the maturation of myeloid progenitor cells is arrested. The myelodysplastic syndrome and acute myeloid leukemia develop in some patients with severe congenital neutropenia. Abnormalities in the signal-transduction pathways for granulocyte colony-stimulating factor (G-CSF) may play a part in the progression to acute myeloid leukemia. METHODS. We isolated genomic DNA and RNA from hematopoietic cells obtained from two patients with acute myeloid leukemia and histories of severe congenital neutropenia. The nucleotide sequences encoding the cytoplasmic domain of the G-CSF receptor were amplified by means of the polymerase chain reaction and sequenced. Murine myeloid 32D.C10 cells were transfected with complementary DNA encoding the wild-type or mutant G-CSF receptors and tested for their responses to G-CSF. RESULTS. Point mutations in the gene for the G-CSF receptor were identified in both patients. The mutations, a substitution of thymine for cytosine at the codon for glutamine at position 718 (Gln718) in one patient and at the codon for glutamine at position 731(Gln731) in the other, caused a truncation of the C-terminal cytoplasmic region of the receptor. Both mutant and wild-type genes for the G-CSF receptor were present in leukemic cells from the two patients. In one patient, the mutation was also found in the neutropenic stage, before the progression to acute myeloid leukemia. The 32D.C10 cells expressing mutant receptors had abnormally high proliferative responses but failed to mature when cultured in G-CSF. The mutant G-CSF receptors also interfered with terminal maturation mediated by the wild-type G-CSF receptor in the 32D.C10 cells that coexpressed the wild-type and mutant receptors. CONCLUSIONS. Mutations in the gene for the G-CSF receptor that interrupt signals required for the maturation of myeloid cells are involved in the pathogenesis of severe congenital neutropenia and associated with the progression to acute myeloid leukemia

Stable long-term risk of leukaemia in patients with severe congenital neutropenia maintained on G-CSF therapy

In severe congenital neutropenia (SCN), long-term therapy with granulocyte colony-stimulating factor (G-CSF) has reduced mortality from sepsis, revealing an underlying predisposition to myelodysplastic syndrome and acute myeloid leukaemia (MDS/AML). We have reported the early pattern of evolution to MDS/AML, but the long-term risk remains uncertain. We updated a prospective study of 374 SCN patients on long-term G-CSF enrolled in the Severe Chronic Neutropenia International Registry. Long-term, the annual risk of MDS/AML attained a plateau (2·3%/year after 10 years). This risk now appears similar to, rather than higher than, the risk of AML in Fanconi anaemia and dyskeratosis congenita.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79264/1/j.1365-2141.2010.08216.x.pd

Ultra-Sensitive CSF3R Deep Sequencing in Patients With Severe Congenital Neutropenia

High frequency of acquired CSF3R (colony stimulating factor 3 receptor, granulocyte) mutations has been described in patients with severe congenital neutropenia (CN) at pre-leukemia stage and overt acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). Here, we report the establishment of an ultra-sensitive deep sequencing of a CSF3R segment encoding the intracellular “critical region” of the G-CSFR known to be mutated in CN-MDS/AML patients. Using this method, we achieved a mutant allele frequency (MAF) detection rate of 0.01%. We detected CSF3R mutations in CN patients with different genetic backgrounds, but not in patients with other types of bone marrow failure syndromes chronically treated with G-CSF (e.g., Shwachman-Diamond Syndrome). Comparison of CSF3R deep sequencing results of DNA and cDNA from the bone marrow and peripheral blood cells revealed the highest sensitivity of cDNA from the peripheral blood polymorphonuclear neutrophils. This approach enables the identification of low-frequency CSF3R mutant clones, increases sensitivity, and earlier detection of CSF3R mutations acquired during the course of leukemogenic evolution of pre-leukemia HSCs of CN patients. We suggest application of sequencing of the entire CSF3R gene at diagnosis to identify patients with inherited lost-of-function CSF3R mutations and annual ultra-deep sequencing of the critical region of CSF3R to monitor acquisition of CSF3R mutations

Histone deacetylase inhibitors induce apoptosis in myeloid leukemia by suppressing autophagy

Histone deacetylase (HDAC)-inhibitors (HDACis) are well characterized anti-cancer agents with promising results in clinical trials. However, mechanistically little is known regarding their selectivity in killing malignant cells while sparing normal cells. Gene expression-based chemical genomics identified HDACis as being particularly potent against Down syndrome associated myeloid leukemia (DS-AMKL) blasts. Investigating the anti-leukemic function of HDACis revealed their transcriptional and posttranslational regulation of key autophagic proteins, including ATG7. This leads to suppression of autophagy, a lysosomal degradation process that can protect cells against damaged or unnecessary organelles and protein aggregates. DS-AMKL cells exhibit low baseline autophagy due to mTOR activation. Consequently, HDAC inhibition repressed autophagy below a critical threshold, which resulted in accumulation of mitochondria, production of reactive oxygen species, DNA-damage and apoptosis. Those HDACi-mediated effects could be reverted upon autophagy activation or aggravated upon further pharmacological or genetic inhibition. Our findings were further extended to other major acute myeloid leukemia subgroups with low basal level autophagy. The constitutive suppression of autophagy due to mTOR activation represents an inherent difference between cancer and normal cells. Thus, via autophagy suppression, HDACis deprive cells of an essential pro-survival mechanism, which translates into an attractive strategy to specifically target cancer cells