Volume 04 · Issue 01 · 2022

The China’s top 10 hematological advances in 2021 was announced at the 2^nd Annual Meeting of Chinese Alliance for Societies of Hematology on January 16, 2022.

DNA methylation is one of the most important components of epigenetics, which plays essential roles in maintaining genome stability and regulating gene expression. In recent years, DNA methylation measuring methods have been continuously optimized. Combined with next generation sequencing technologies, these approaches have enabled the detection of genome-wide cytosine methylation at single-base resolution. In this paper, we review the development of 5-methylcytosine and its oxidized derivatives measuring methods, and recent advancement of single-cell epigenome sequencing technologies, offering more referable information for the selection and optimization of DNA methylation sequencing technologies and related research.

T cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematologic malignancy often associated with poor outcomes. To identify high-risk factors and potential actionable targets for T-ALL, we perform integrated genomic and transcriptomic analyses on samples from 165 Chinese pediatric and adult T-ALL patients, of whom 85% have outcome information. The genomic mutation landscape of this Chinese cohort is very similar to the Western cohort published previously, except that the rate of NOTCH1 mutations is significant lower in the Chinese T-ALL patients. Among 47 recurrently mutated genes in 7 functional categories, we identify RAS pathway and PTEN mutations as poor survival factors for non-TAL and TAL subtypes, respectively. Mutations in the PI3K pathway are mutually exclusive with mutations in the RAS and NOTCH1 pathways as well as transcription factors. Further analysis demonstrates that approximately 43% of the high-risk patients harbor at least one potential actionable alteration identified in this study, and T-ALLs with RAS pathway mutations are hypersensitive to MEKi in vitro and in vivo. Thus, our integrated genomic analyses not only systematically identify high-risk factors but suggest that these high-risk factors are promising targets for T-ALL therapies.

Variants in the solute carrier family 40 member 1 (SLC40A1) gene are the molecular basis of ferroportin disease, which is an autosomal dominant hereditary hemochromatosis. Here, we present a patient with pure red cell aplasia (PRCA) and large granular lymphocytic leukemia (LGLL) associated with an extremely high levels of serum ferritin and iron overload syndrome. Whole exon sequencing revealed a novel heterozygous variant in SLC40A1 (p.T419I), which was found in his daughter as well. A series of functional studies in vitro of the T419I variant in ferroportin were conducted and the results revealed a reduced capacity of iron export from cells without changes in protein localization and its sensitivity to hepcidin. Intracellular iron storage in mutated cells was significantly higher than that of wild-type. These findings suggest that the novel variant p.T419I can cause the classical form of ferroportin disease and an elevated intracellular iron level indicates a potential novel pathogenic mechanism underlying PRCA and LGLL.