Cancer cells utilize the main de novo pathway and the alternative salvage pathway for deoxyribonucleotide biosynthesis to achieve adequate nucleotide pools. Deoxycytidine kinase is the rate-limiting ...enzyme of the salvage pathway and it has recently emerged as a target for anti-proliferative therapies for cancers where it is essential. Here, we present the development of a potent inhibitor applying an iterative multidisciplinary approach, which relies on computational design coupled with experimental evaluations. This strategy allows an acceleration of the hit-to-lead process by gradually implementing key chemical modifications to increase affinity and activity. Our lead compound, OR0642, is more than 1000 times more potent than its initial parent compound, masitinib, previously identified from a drug repositioning approach. OR0642 in combination with a physiological inhibitor of the de novo pathway doubled the survival rate in a human T-cell acute lymphoblastic leukemia patient-derived xenograft mouse model, demonstrating the proof-of-concept of this drug design strategy.
The acquisition of genetic abnormalities engendering oncogene dysregulation underpins cancer development. Certain proto-oncogenes possess several dysregulation mechanisms, yet how each mechanism ...impacts clinical outcome is unclear. Using T-cell acute lymphoblastic leukemia (T-ALL) as an example, we show that patients harboring 5'super-enhancer (5'SE) mutations of the TAL1 oncogene identifies a specific patient subgroup with poor prognosis irrespective of the level of oncogene dysregulation. Remarkably, the MYB dependent oncogenic 5'SE can be targeted using Mebendazole to induce MYB protein degradation and T-ALL cell death. Of note Mebendazole treatment demonstrated efficacy in vivo in T-ALL preclinical models. Our work provides proof of concept that within a specific oncogene driven cancer, the mechanism of oncogene dysregulation rather than the oncogene itself can identify clinically distinct patient subgroups and pave the way for future super-enhancer targeting therapy.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Cancer cells undergo massive alterations in their DNA methylation patterns which result in aberrant gene expression and malignant phenotypes. Abnormal DNA methylation is a prognostic marker in ...several malignancies, but its potential prognostic significance in adult T-cell acute lymphoblastic leukemia (T-ALL) is poorly defined. Here, we performed methylated DNA immunoprecipitation to obtain a comprehensive genome-wide analysis of promoter methylation in adult T-ALL (n=24) compared to normal thymi (n=3). We identified a CpG hypermethylator phenotype that distinguishes two T-ALL subgroups and further validated it in an independent series of 17 T-lymphoblastic lymphoma. Next, we identified a methylation classifier based on nine promoters which accurately predict the methylation phenotype. This classifier was applied to an independent series of 168 primary adult T-ALL treated accordingly to the GRAALL03/05 trial using methylation-specific multiplex ligation-dependent probe amplification. Importantly hypomethylation correlated with specific oncogenic subtypes of T-ALL and identified patients associated with a poor clinical outcome. This methylation-specific multiplex ligation-dependent probe amplification based methylation profiling could be useful for therapeutic stratification of adult T-ALL in routine practice. The GRAALL-2003 and -2005 studies were registered at http://www.clinicaltrials.gov as #NCT00222027 and #NCT00327678, respectively.
Monocytes/macrophages are major effectors of lung inflammation associated with various forms of pulmonary hypertension (PH). Interactions between the CCL2/CCR2 and CX3CL1/CX3CR1 chemokine systems ...that guide phagocyte infiltration are incompletely understood. Our objective was to explore the individual and combined actions of CCL2/CCR2 and CX3CL1/CX3CR1 in hypoxia-induced PH in mice; particularly their roles in monocyte trafficking, macrophage polarization, and pulmonary vascular remodeling. The development of hypoxia-induced PH was associated with marked increases in lung levels of CX3CR1, CCR2, and their respective ligands, CX3CL1 and CCL2. Flow cytometry revealed that both inflammatory Ly6C
and resident Ly6C
monocyte subsets exhibited sustained increases in blood and a transient peak in lung tissue, and that lung perivascular and alveolar macrophage counts showed sustained elevations. CX3CR1
mice were protected against hypoxic PH compared with wild-type mice, whereas CCL2
mice and double CX3CR1
/CCL2
mice exhibited similar PH severity, as did wild-type mice. The protective effects of CX3CR1 deficiency occurred concomitantly with increases in lung monocyte and macrophage counts and with a change from M2 to M1 macrophage polarization that markedly diminished the ability of conditioned media to induce pulmonary artery smooth muscle cell (PA-SMC) proliferation, which was partly dependent on CX3CL1 secretion. Results in mice given the CX3CR1 inhibitor F1 were similar to those in CX3CR1
mice. In conclusion, CX3CR1 deficiency protects against hypoxia-induced PH by modulating monocyte recruitment, macrophage polarization, and PA-SMC cell proliferation. Targeting CX3CR1 may hold promise for treating PH.
Adult "T cell" acute lymphoblastic leukemia (T-ALL) is an aggressive hematological malignancy that is associated with poor outcomes, requiring additional therapeutic options. The DNA methylation ...landscapes of adult T-ALL remain undercharacterized. Here, we systematically analyzed the DNA methylation profiles of normal thymic-sorted T cell subpopulations and 143 primary adult T-ALLs as part of the French GRAALL 2003-2005 trial. Our results indicated that T-ALL is epigenetically heterogeneous consisting of five subtypes (C
-C
), which were either associated with co-occurring
(
)/
(
)
(
) mutations (C
),
,
(
) deregulation (C
),
(
) (C
),
/in
-
(
) (C
), or in
-
overexpression (C
). Integrative analysis of DNA methylation and gene expression identified potential cluster-specific oncogenes and tumor suppressor genes. In addition to an aggressive hypomethylated subgroup (C
), our data identified an unexpected subset of hypermethylated T-ALL (C
) associated with poor outcome and primary therapeutic response. Using mouse xenografts, we demonstrated that hypermethylated T-ALL samples exhibited therapeutic responses to the DNA hypomethylating agent 5-azacytidine, which significantly (survival probability;
= 0.001 for C
, 0.01 for C
, and 0.0253 for C
) delayed tumor progression. These findings suggest that epigenetic-based therapies may provide an alternative treatment option in hypermethylated T-ALL.
Biological explanation for discrepancies in patient-related response to chemotherapy depending on the underlying oncogenic events is a promising research area. TLX1- or TLX3-deregulated T-cell acute ...lymphoblastic leukemias (T-ALL; TLX1/3
) share an immature cortical phenotype and similar transcriptional signatures. However, their prognostic impacts differ, and inconsistent clinical outcome has been reported for TLX3. We therefore hypothesized that the overlapping transcriptional profiles of TLX1
and TLX3
T-ALLs would allow identification of candidate genes, which might determine their distinct clinical outcomes.
We compared TLX1
and TLX3
adult T-ALL outcome in the successive French national LALA-94 and GRAALL-2003/2005 multicentric trials and analyzed transcriptomic data to identify differentially expressed genes. Epigenetic regulation of asparagine synthetase (
) and
l-asparaginase sensitivity were evaluated for T-ALL cell lines and primary samples.
We show that TLX1
patients expressed low levels of
when compared with TLX3
and TLX-negative patients, due to epigenetic silencing of
by both DNA methylation and a decrease of active histone marks. Promoter methylation of the
gene correlated with l-asparaginase sensitivity in both T-ALL cell lines and patient-derived xenografts. Finally,
promoter methylation was an independent prognostic factor for both event-free survival HR, 0.42; 95% confidence interval (CI), 0.24-0.71;
= 0.001 and overall survival (HR, 0.40; 95% CI, 0.23-0.70;
= 0.02) in 160 GRAALL-2003/2005 T-ALL patients and also in an independent series of 47 LL03-treated T lymphoblastic lymphomas (
= 0.012).
We conclude that
methylation status at diagnosis may allow individual adaptation of l-asparaginase dose.
Extranodal NK/T-cell lymphoma (ENKTCL) is an Epstein-Barr virus (EBV)-related neoplasm with male dominance and a poor prognosis. A better understanding of the genetic alterations and their functional ...roles in ENKTCL could help improve patient stratification and treatments. Here, we performed comprehensive genetic analysis of 177 ENKTCL cases to delineate the landscape of mutations, copy number alterations (CNAs), and structural variations, identifying 34 driver genes including six previously unappreciated ones, namely HLA-B, HLA-C, ROBO1, CD58, POT1, and MAP2K1. Among them, CD274 (24%) was the most frequently altered, followed by TP53 (20%), CDKN2A (19%), ARID1A (15%), HLA-A (15%), BCOR (14%), and MSN (14%). Chromosome X (chrX) losses were the most common arm-level CNAs in females (~40%), and alterations of four X-linked driver genes (MSN, BCOR, DDX3X, and KDM6A) were more frequent in males and females harboring chrX losses. Among X-linked drivers, MSN was the most recurrently altered, and its expression was lost in approximately one-third of cases using immunohistochemical analysis. Functional studies of human cell lines demonstrated that MSN disruption promoted cell proliferation and NF-κB activation. Moreover, MSN inactivation increased sensitivity to NF-κB inhibition in vitro and in vivo. In addition, recurrent deletions were observed at the origin of replication in the EBV genome (6%). Finally, by integrating the 34 drivers and 19 significant arm-level CNAs, non-negative matrix factorization and consensus clustering identified two molecular groups with different genetic features and prognosis irrespective of clinical prognostic factors. Together, these findings could help improve diagnostic and therapeutic strategies in ENKTCL.
In a recent systematic review, aging has been identified as the only factor independently associated with mortality during human acute respiratory distress syndrome (ARDS). We explored this ...age-dependent severity in a clinically relevant double hit murine ARDS model.
Young adult (Y, 10–12weeks) and middle-old (O, 12–13months) male C57BL6 mice underwent an aspiration of Escherichia coli lipopolysaccharide (LPS) or control saline vehicle. Twenty hours later, four groups of mice were sacrificed Y(control), O(control), Y(LPS) and O(LPS). Four other groups of mice underwent 3h of low tidal volume (8mL/kg) mechanical ventilation (MV) Y(MV), O(MV), Y(LPS+MV) and O(LPS+MV). Lung mechanics were assessed hourly during MV. Right ventricular pressure and cardiac output were measured at the end of the MV. After sacrifice, lung inflammation, edema and injury were explored with bronchoalveolar lavage (BAL) and histology.
After saline aspiration, middle-old mice had a higher respiratory system compliance than young adult mice. LPS aspiration dramatically altered the baseline compliance in middle-old (O(LPS)), but not in young adult (Y(LPS)) mice. Middle-old mice had a more pronounced alteration in lungs mechanics during MV as compared to young adult mice. Lung inflammation (as assessed by the total cell count, IL-6, TNFα and MIP-2 concentrations in BAL fluid), systemic inflammation (as assessed by plasma IL-6 concentration) and alveolocapillary leak (as assessed by the total protein concentration of BAL fluid) were higher in O(LPS) and O(LPS+MV) mice as compared to Y(LPS) and Y(LPS+MV) mice, respectively. The combination of LPS+MV induced a higher lung injury as compared to LPS alone in middle-old mice but not in young adult mice. Hemodynamics (systemic blood pressure, cardiac output and pulmonary vascular resistances) were similar between Y(MV) and O(MV) on the one hand and between Y(LPS+MV) and O(LPS+MV) on the other hand.
Middle-old mice were more susceptible to both LPS alone and the combination of LPS and low tidal volume MV as compared to their young adult counterparts. The synergism between LPS and MV was amplified in middle-old mice.
•A clinically relevant double hit murine model of ARDS is used.•LPS aspiration and low tidal volume mechanical ventilation are combined.•An aged-dependent severity is observed.•Middle-old mice are more susceptible to LPS aspiration than young adult mice.•Synergism between LPS and mechanical ventilation is amplified in middle-old mice.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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