Our findings demonstrate that Ras oncogene-independent activation of RALB signaling is a therapeutically targetable mechanism of escape from NRAS oncogene addiction in AML.
Mutations of the NRAS and TP53 genes and internal tandem duplication (ITD) of the FLT3 gene are among the most frequently observed molecular abnormalities in the myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML).
CYP1A1*2B (Val) high-inducibility variant allele was overrepresented in patients with NRAS mutation compared with no mutation, for (1) the entire AML cohort (n = 8/53 vs 26/371; odds ratio [OR] = 2.36; 95% confidence interval [CI] 1.01-5.53) and (2) the poor-risk karyotype group (n = 6/14 vs 4/89; OR = 15.94; 95% CI 3.71-68.52) comprising patients with partial/complete deletion of chromosome 5 or 7, or abnormalities of chromosome 3.
As activation of Evi1 has been shown to coincide with NRAS mutations in human acute myeloid leukemia, our murine model recapitulates crucial events in human leukemogenesis.
Taken together, our findings provide new insight into the mechanism of wogonoside-induced nuclear translocation of PLSCR1 and illuminate the influence of N-RAS depalmitoylation on its Golgi trafficking and RAF1 signalling inactivation in AML.
Here we demonstrate the presence of a transforming N-ras gene in bone marrow cells from a patient with acute myeloblastic leukaemia at the outbreak of the acute disease phase.
These results suggest that mutation of the NF1 gene, at least in the FLR exon, is very rare in AML and the NF1 gene probably is not a functional complement of the N-ras gene mutation.
RAS mutations are frequent in FAB type M4 and M5 of acute myeloid leukemia, and related to late relapse: a study of the Japanese Childhood AML Cooperative Study Group.
Other abnormalities are also relatively specific but occur in only some cases such as NRAS in acute myelogenous leukemia or BCL2 in B-cell acute lymphoblastic leukemia.
An activated c-N-ras gene from a 45-year-old patient with AML was isolated by transfection analysis and subjected to molecular cloning and sequence analysis.
We analyzed 2502 patients with acute myeloid leukemia at diagnosis for NRAS mutations around the hot spots at codons 12, 13, and 61 and correlated the results to cytomorphology, cytogenetics, other molecular markers, and prognostic relevance of these mutations.
These results suggest that the amplification of c-MYC gene is common in dmin-positive AML patients and co-ordination of c-MYC and N-RAS oncogene might also play a significant role in the pathogenesis of some AML patients.
One of the compounds identified, GNF-7, potently and selectively inhibited NRAS-dependent cells in preclinical models of acute myelogenous leukemia and acute lymphoblastic leukemia.
This study showed that cooperation of DNMT3A mutation and NRAS mutation could promote the onset of AML by synergistically disturbing the transcriptional profiling with Myc pathway involvement in DKI mice.