MLL fusion proteins are leukemogenic, but their mechanism is unclear. Induced dimerization of a truncated MLL immortalizes bone marrow and imposes a reversible block on myeloid differentiation associated with upregulation of Hox a7, a9, and Meis1. Both dimerized MLL and exon-duplicated MLL are potent transcriptional activators, suggesting a link between dimerization and partial tandem duplication of DNA binding domains of MLL. Dimerized MLL binds with higher affinity than undimerized MLL to a CpG island within the Hox a9 locus. However, MLL-AF9 is not dimerized in vivo. The data support a model in which either MLL dimerization/exon duplication or fusion to a transcriptional activator results in Hox gene upregulation and ultimately transformation.
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http://dx.doi.org/10.1016/s1535-6108(03)00214-9 | DOI Listing |
Adv Protein Chem Struct Biol
January 2025
Laboratory of Integrative Genomics, Department of Integrative Biology, School of BioSciences and Technology, Vellore Institute of Technology (VIT), Vellore, Tamil Nadu, India. Electronic address:
The prognosis for mixed-lineage leukemia (MLL), particularly in young children, remains a significant health concern due to the limited therapeutic options available. MLL refers to KMT2A chromosomal translocations that produce MLL fusion proteins. The protein menin, which is essential for the malignant potential of these MLL fusion proteins, offers novel targets for acute leukemia treatment.
View Article and Find Full Text PDFZhongguo Dang Dai Er Ke Za Zhi
January 2025
Department of Children's Hematology and Oncology, First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China.
Objectives: To investigate the clinical characteristics and prognosis of acute erythroleukemia (AEL) in children.
Methods: A retrospective analysis was conducted on the clinical data, treatment, and prognosis of 8 children with AEL treated at the First Affiliated Hospital of Zhengzhou University from January 2013 to December 2023.
Results: Among the 7 patients with complete bone marrow morphological analysis, 4 exhibited trilineage dysplasia, with a 100% incidence of erythroid dysplasia (7/7), a 71% incidence of myeloid dysplasia (5/7), and a 57% incidence of megakaryocytic dysplasia (4/7).
Drug Resist Updat
January 2025
Loma Linda University Cancer Center, Loma Linda, CA 92354, United States; Department of Basic Sciences, Loma Linda University, Loma Linda, CA 92354, United States. Electronic address:
Chromosomal rearrangements (CR) initiate leukemogenesis in approximately 50 % of acute myeloid leukemia (AML) patients; however, limited targeted therapies exist due to a lack of accurate molecular and genetic biomarkers of refractory mechanisms during treatment. Here, we investigated the pathological landscape of treatment resistance and relapse in 16 CR-AML patients by monitoring cytogenetic, RNAseq, and genome-wide changes among newly diagnosed, refractory, and relapsed AML. First, in FISH-diagnosed KMT2A (MLL gene, 11q23)/AFDN (AF6, 6q27)-rearrangement, RNA-sequencing identified an unknown CCDC32 (15q15.
View Article and Find Full Text PDFCancers (Basel)
January 2025
Hematology Unit, S. Eugenio Hospital (ASL Roma 2), 00122 Rome, Italy.
Menin (MEN1) is a well-recognized powerful tumor promoter in acute leukemias (AL) with KMT2A rearrangements (KMT2Ar, also known as MLL) and mutant nucleophosmin 1 (NPM1m) acute myeloid leukemia (AML). MEN1 is essential for sustaining leukemic transformation due to its interaction with wild-type KMT2A and KMT2A fusion proteins, leading to the dysregulation of KMT2A target genes. MEN1 inhibitors (MIs), such as revumenib, ziftomenib, and other active small molecules, represent a promising new class of therapies currently under clinical development.
View Article and Find Full Text PDFSheng Li Xue Bao
December 2024
State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China.
The objective of the present study was to investigate the role and mechanism of bone marrow microenvironmental cells in regulating the mitochondrial mass of leukemia cells, and to uncover the mechanism of leukemia progression at the metabolic level. A mouse model of acute myeloid leukemia (AML) induced by the overexpression of the MLL-AF9 (MA9) fusion protein was established, and the bone marrow cells of AML mice were transplanted into mitochondrial fluorescence reporter mice expressing the Dendra2 protein (mito-Dendra2 mice). The proportion of Dendra2 cells in bone marrow leukemia cells at different stages of AML was quantified by flow cytometry.
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