Mutations in receptor tyrosine kinase/RAS signaling pathway genes are frequent in core-binding factor (CBF) acute myeloid leukemias (AMLs), but their prognostic relevance is debated. A subset of CBF ...AML patients harbors several signaling gene mutations. Genotyping of colonies and of relapse samples indicates that these arise in independent clones, thus defining a process of clonal interference (or parallel evolution). Clonal interference is pervasive in cancers, but the mechanisms underlying this process remain unclear, and its prognostic impact remains unknown. We analyzed a cohort of 445 adult and pediatric patients with CBF AML treated with intensive chemotherapy and with deep sequencing of 6 signaling genes (KIT, NRAS, KRAS, FLT3, JAK2, CBL). A total of 152 (34%), 167 (38%), and 126 (28%) patients harbored no, a single, and multiple signaling clones (clonal interference), respectively. Clonal interference of signaling mutations was associated with older age (P = .004) and inv(16) subtype (P = .025) but not with white blood cell count or mutations in chromatin or cohesin genes. The median allele frequency of signaling mutations was 31% in patients with a single clone or clonal interference (P = .14). The repertoire of KIT, FLT3, and NRAS/KRAS variants differed between groups. Clonal interference did not affect complete remission rate or minimal residual disease after 1-2 courses, but it did convey inferior event-free survival (P < 10−4), whereas the presence of a single signaling clone did not (P = .44). This inferior outcome was independent of clinical parameters and of the presence of specific signaling clones. Our results suggest that specific clonal architectures can herald distinct prognoses in AML.
•Presence of ≥2 independent subclones in the receptor tyrosine kinase/RAS pathway, defining clonal interference, is found in 28% of CBF AMLs.•Clonal interference predicts shorter event-free survival independently of clinical variables and presence of specific signaling mutations.
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Retrospective comparisons have suggested that adolescents or teenagers with acute lymphoblastic leukemia (ALL) benefit from pediatric rather than adult chemotherapy regimens. Thus, the aim of the ...present phase II study was to test a pediatric-inspired treatment, including intensified doses of nonmyelotoxic drugs, such as prednisone, vincristine, or L-asparaginase, in adult patients with ALL up to the age of 60 years.
Between 2003 and 2005, 225 adult patients (median age, 31 years; range, 15 to 60 years) with Philadelphia chromosome-negative ALL were enrolled onto the Group for Research on Adult Acute Lymphoblastic Leukemia 2003 protocol, which included several pediatric options. Some adult options, such as allogeneic stem-cell transplantation for patients with high-risk ALL, were nevertheless retained.
were retrospectively compared with the historical France-Belgium Group for Lymphoblastic Acute Leukemia in Adults 94 (LALA-94) trial experience in 712 patients age 15 to 55 years. Results Complete remission rate was 93.5%. At 42 months, event-free survival (EFS) and overall survival (OS) rates were 55% (95% CI, 48% to 52%) and 60% (95% CI, 53% to 66%), respectively. Age remained an important bad prognostic factor, with 45 years of age as best cutoff. In older versus younger patients, there was a higher cumulative incidence of chemotherapy-related deaths (23% v 5%, respectively; P < .001) and deaths in first CR (22% v 5%, respectively; P < .001), whereas the incidence of relapse remained stable (30% v 32%, respectively). Complete remission rate (P = .02), EFS (P < .001), and OS (P < .001) compared favorably with the previous LALA-94 experience.
These results suggest that pediatric-inspired therapy markedly improves the outcome of adult patients with ALL, at least until the age of 45 years.
The prognostic implications of
genotype in T-cell acute lymphoblastic leukemia are incompletely understood. We performed comprehensive genetic and clinico-biological analyses of T-cell acute ...lymphoblastic leukemia patients with
mutations treated during the GRAALL-2003 and -2005 studies. Eighteen of 198 cases (9.1%) had
alterations. Two patients also had
mutations in non-leukemic cell DNA, providing the first potential evidence of age-related clonal hematopoiesis in T-cell acute lymphoblastic leukemia.
mutation was associated with older age (median 43.9 years
29.4 years,
<0.001), immature T-cell receptor genotype (53.3%
24.4%,
=0.016) and lower remission rates (72.2% mutated
94.4% non-mutated,
=0.006).
alterations were significantly associated with worse clinical outcome, with higher cumulative incidence of relapse (HR 2.33, 95% CI: 1.05-5.16,
=0.037) and markedly poorer event-free survival (HR 3.22, 95% CI: 1.81-5.72,
<0.001) and overall survival (HR 2.91, 95% CI: 1.56-5.43,
=0.001). Adjusting for age as a covariate, or restricting the analysis to patients over 40 years, who account for almost 90% of
-mutated cases, did not modify these observations. In multivariate analysis using the risk factors that were used to stratify treatment during the GRAALL studies,
mutation was significantly associated with shorter event-free survival (HR 2.33, 95% CI: 1.06 - 4.04,
=0.02). Altogether, these results identify
genotype as a predictor of aggressive T-cell acute lymphoblastic leukemia biology. The GRAALL-2003 and -2005 studies were registered at
as
and
, respectively.
Acquired somatic deletions and loss-of-function mutations in one or several codons of the TET2 (Ten-Eleven Translocation-2) gene were recently identified in hematopoietic cells from patients with ...myeloid malignancies, including myeloproliferative disorders and myelodys-plastic syndromes. The present study was designed to determine the prevalence of TET2 gene alterations in chronic myelomonocytic leukemias.
Blood and bone marrow cells were collected from 88 patients with chronic phase chronic myelomonocytic leukemia and from 14 with acute transformation of a previously identified disease. Polymerase chain reaction analysis and direct sequencing were used to sequence exons 3 to 11 of the TET2 gene. Annotated single nucleotide polymorphisms were excluded. Survival curves were constructed by the Kaplan-Meier method.
We detected TET2 mutations in 44 of 88 (50%) patients with chronic myelomonocytic leukemia, which suggests that TET2 gene mutations are especially frequent in this myeloid disease. A TET2 gene alteration was identified in 18 of the 43 patients studied at diagnosis and was associated with a trend to a lower overall survival rate; confining the analysis to the 29 patients with chronic myelomonocytic leukemia-1, according to the WHO classification, the difference in overall survival between patients with or without TET2 gene mutations became statistically significant.
TET2 gene alterations are more frequent in chronic myelomonocytic leukemia than in other subgroups of hematopoietic diseases studied so far and could negatively affect the patients' outcome. The striking association between TET2 gene alterations and monocytosis, already observed in patients with systemic mastocytosis, could indicate a negative role of TET2 in the control of monocytic lineage determination.
T-cell acute lymphoblastic leukemias (T-ALL) represent 15% of pediatric and 25% of adult ALL. Since they have a particularly poor outcome in relapsed/refractory cases, identifying prognosis factors ...at diagnosis is crucial to adapting treatment for high-risk patients. Unlike acute myeloid leukemia and BCP ALL, chromosomal rearrangements leading to chimeric fusion-proteins with strong prognosis impact are sparsely reported in T-ALL. To address this issue an RT-MPLA assay was applied to a consecutive series of 522 adult and pediatric T-ALLs and identified a fusion transcript in 20% of cases. PICALM-MLLT10 (4%, n = 23), NUP214-ABL1 (3%, n = 19) and SET-NUP214 (3%, n = 18) were the most frequent. The clinico-biological characteristics linked to fusion transcripts in a subset of 235 patients (138 adults in the GRAALL2003/05 trials and 97 children from the FRALLE2000 trial) were analyzed to identify their prognosis impact. Patients with HOXA trans-deregulated T-ALLs with MLLT10, KMT2A and SET fusion transcripts (17%, 39/235) had a worse prognosis with a 5-year EFS of 35.7% vs 63.7% (HR = 1.63; p = 0.04) and a trend for a higher cumulative incidence of relapse (5-year CIR = 45.7% vs 25.2%, HR = 1.6; p = 0.11). Fusion transcripts status in T-ALL can be robustly identified by RT-MLPA, facilitating risk adapted treatment strategies for high-risk patients.
Finding an effective treatment for acute myeloid leukemia (AML) remains a challenge, and all cellular processes that are deregulated in AML cells should be considered in the design of targeted ...therapies. We show in our current study that the LKB1/AMPK/TSC tumor suppressor axis is functional in AML and can be activated by the biguanide molecule metformin, resulting in a specific inhibition of mammalian target of rapamycin (mTOR) catalytic activity. This induces a multisite dephosphorylation of the key translation regulator, 4E-BP1, which markedly inhibits the initiation step of mRNA translation. Consequently, metformin reduces the recruitment of mRNA molecules encoding oncogenic proteins to the polysomes, resulting in a strong antileukemic activity against primary AML cells while sparing normal hematopoiesis ex vivo and significantly reducing the growth of AML cells in nude mice. The induction of the LKB1/AMPK tumor-suppressor pathway thus represents a promising new strategy for AML therapy.
The deregulation of translation markedly contributes to the malignant phenotype in cancers, and the assembly of the translation initiating complex eIF4F is the limiting step of this process. The ...mammalian Target of Rapamycin Complex 1 (mTORC1) is thought to positively regulate eIF4F assembly and subsequent oncogenic protein synthesis through 4E-BP1 phosphorylation. We showed here that the translation inhibitor 4EGI-1 decreased the clonogenic growth of leukemic progenitors and induced apoptosis of blast cells, with limited toxicity against normal hematopoiesis, which emphasize the importance of translation deregulation in acute myeloid leukemia (AML) biology. However, the mTORC1 inhibitor RAD001 (a rapamycin derivate) did not induce AML blast cell apoptosis. We herein demonstrated that mTORC1 disruption using raptor siRNA or RAD001 failed to inhibit 4E-BP1 phosphorylation in AML. Moreover, RAD001 failed to inhibit eIF4F assembly, to decrease the proportion of polysome-bound c-Myc mRNA, and to reduce the translation-dependent accumulation of oncogenic proteins. We identified the Pim-2 serine/threonine kinase as mainly responsible for 4E-BP1 phosphorylation on the S65 residue and subsequent translation control in AML. Our results strongly implicate an mTORC1-independent deregulation of oncogenic proteins synthesis in human myeloid leukemogenesis. Direct inhibition of the translation initiating complex thus represents an attractive option for the development of new therapies in AML.
The prognostic value of IL7-receptor pathway (IL7Rp) mutations in T-cell acute lymphoblastic leukemia (T-ALL) remains unclear. We performed a comprehensive study of 200 adult patients with T-ALL ...included in the GRAALL2003/2005 protocols to address the clinical significance of IL7Rp mutations. Next-generation sequencing of the IL7Rp (IL7R/JAK1/JAK3/STAT5B) revealed that IL7Rp mutations were frequent in adult T-ALL (28%) particularly in immature/early T-cell progenitor (ETP)-ALL. They were associated with mutations of NOTCH-pathway, PHF6, and PRC2 components but not with K/NRAS. IL7Rp mutated (IL7Rp
) T-ALL were slow-responders, with a high rate of M2/M3 day-8 marrow compared with IL7Rp non-mutated (IL7Rp
) T-ALL (p = 0.002) and minimal residual disease positivity at 6-weeks (MRD1) (p = 0.008) but no difference in MRD2 positivity at 12-weeks. Despite this, no adverse prognosis was evidenced when censored for allogeneic hematopoietic stem cell transplantation (HSCT). In time-dependent analysis, HSCT did not benefit IL7Rp
patients whereas it was of marked benefit to IL7Rp
cases. IL7Rp-mutations identify a subgroup of slow-responder T-ALLs which benefit from post-induction chemotherapy regimens but not from HSCT. Our data suggest that prior knowledge of the mutation status of IL7Rp may influence HSCT decision and help to guide therapy reduction.
The phosphatidylinositol 3-kinase (PI3K)/Akt and mTORC1 pathways are frequently activated, representing potential therapeutic targets in acute myeloid leukemia (AML). In 19 AML samples with ...constitutive PI3K/Akt activation, the rapamycin derivative inhibitor everolimus (RAD001) increased Akt phosphorylation. This mTOR C1-mediated Akt up-regulation was explained by an insulin-like growth factor-1 (IGF-1)/IGF-1 receptor autocrine loop: (1) blast cells expressed functional IGF-1 receptors, and IGF-1-induced Akt activation was increased by RAD001, (2) a neutralizing anti-IGF-1R α-IR3 monoclonal antibody reversed the RAD001-induced Akt phosphorylation, and (3) autocrine production of IGF-1 was detected in purified blast cells by quantitative reverse transcription-polymerase chain reaction and immunofluorescence. This RAD001-induced PI3K/Akt up-regulation was due to an up-regulated expression of the IRS2 adaptor. Finally, we observed that concomitant inhibition of mTORC1 and PI3K/Akt by RAD001 and IC87114 induced additive antiproliferative effects. Our results suggest that dual inhibition of the mTORC1 complex and the IGF-1/IGF-1R/PI3K/Akt pathway in AML may enhance the efficacy of mTOR inhibitors in treatment of this disease.
The growth and survival of acute myeloid leukemia (AML) cells are enhanced by the deregulation of signaling pathways such as phosphoinositide 3-kinase (PI3K)/Akt and mammalian target of rapamycin ...(mTOR). Major efforts have thus been made to develop molecules targeting these activated pathways. The mTOR serine/threonine kinase belongs to two separate complexes: mTORC1 and mTORC2. The mTORC1 pathway is rapamycin sensitive and controls protein translation through the phosphorylation of 4E-BP1 in most models. In AML, however, the translation process is deregulated and rapamycin resistant. Furthermore, the activity of PI3K/Akt and mTOR is closely related, as mTORC2 activates the oncogenic kinase Akt. We therefore tested, in this study, the antileukemic activity of the dual PI3K/mTOR ATP-competitive inhibitor NVP-BEZ235 compound (Novartis).
The activity of NVP-BEZ235 was tested in primary AML samples (n = 21) and human leukemic cell lines. The different signaling pathways were analyzed by Western blotting. The cap-dependent mRNA translation was studied by 7-methyl-GTP pull-down experiments, polysomal analysis, and (3)Hleucine incorporation assays. The antileukemic activity of NVP-BEZ235 was tested by analyzing its effects on leukemic progenitor clonogenicity, blast cell proliferation, and survival.
The NVP-BEZ235 compound was found to inhibit PI3K and mTORC1 signaling and also mTORC2 activity. Furthermore, NVP-BEZ235 fully inhibits the rapamycin-resistant phosphorylation of 4E-BP1, resulting in a marked inhibition of protein translation in AML cells. Hence, NVP-BEZ235 reduces the proliferation rate and induces an important apoptotic response in AML cells without affecting normal CD34(+) survival.
Our results clearly show the antileukemic efficiency of the NVP-BEZ235 compound, which therefore represents a promising option for future AML therapies.
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