Initial p53 mutation screening of blast cells from 29 patients with acute leukaemia by PCR-denaturing gradient gel electrophoresis showed that 2 had a silent codon 213 polymorphism and only the index case had a somatic mutation identified to be an 8 bp insertion in codon 281 (5'CCGGGGGG-3').
A cohort of 75 MDS patients were investigated for RAS, FMS and p53 mutations, and these molecular findings were related to cytogenetics, clinical status, transformation to acute leukemia, prognostic scores and survival.
Overall, our data suggest that (1) TP53 inactivation is a relatively common event in leukemias with MLL rearrangements irrespective of the leukemic phenotype and of the patients' age; (2) at least two genetic lesions (i.e., MLL rearrangement and TP53 mutation) have accumulated in the short time (few weeks after the birth or conception of the child) corresponding to the development of acute leukemias of infancy.
Thus, disruption of regulated p53 expression resulting in lack of detectable p53 mRNA even by RT-PCR occurs in about 30% of cases of AML; however, p53 alterations typical for human solid tumors are an infrequent event in most types of human acute leukemias.
The expression of p53 was studied in 9 cell lines and 17 de novo acute leukemia (9 acute myeloid leukemia [AML], 8 acute lymphoblastic leukemia [ALL]) patients.
Immunohistochemical studies for GATA1 expression were performed on bone marrow biopsy specimens to define its role in the evaluation of acute leukemia and other hematologic disorders.
We did not find mutations in GATA1 in leukemic cells of DS patients with other types of acute leukemia, or in other patients with AMKL who did not have DS.
These mutations include JAK2, CALR and MPL mutations as the main disease drivers, mutations driving clonal expansion, and mutations that contribute to progression of chronic MPNs to myelodysplasia and acute leukemia.
These mutations include JAK2, CALR and MPL mutations as the main disease drivers, mutations driving clonal expansion, and mutations that contribute to progression of chronic MPNs to myelodysplasia and acute leukemia.
KMT2A-MLLT10 is one of the common chimeric genes diagnosed in acute leukemia with KMT2A rearrangement (8%), especially in acute myeloid leukemia (AML; 18%).
Although it is presently unclear whether these sarcomas belong to a single group, the well-established role of KMT2A fusions as drivers of acute leukaemia and a recent publication regarding identification of YAP1-KMT2A in one unclassifiable sarcoma support the significance of these fusions.
Overlap of MLL bcr sequences associated with both infant acute leukemia and therapy-related leukemia following exposure to the topoisomerase II inhibitor etoposide led to the hypothesis that exposure during pregnancy to biochemically similar compounds may promote infant acute leukemia.
The MLLT10 (formerly AF10) gene is the fourth most common KMT2A fusion partner across all acute leukemias and requires at least 3 breaks to form an in-frame KMT2A/MLLT10 fusion due to the opposite orientation of each gene.
This study aimed at assessing if the cell-of-origin of t(4;11) MLL-AF4 acute leukemia is sensitive to a viral or bacterial mimic and if maternal immune activation can lead to a full-blown leukemia.