T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive cancer arising from lymphoblasts of T-cell origin. While TALL accounts for only 15% of childhood and 25% of adult ALL, 30% of patients relapse with a poor outcome. Targeted therapy of resistant and high-risk pediatric T-ALL is therefore urgently needed, together with precision medicine tools allowing the testing of efficacy in patient samples. Furthermore, leukemic cell heterogeneity requires drug response assessment at the single-cell level. Here we used single-cell mass cytometry to study signal transduction pathways such as JAK-STAT, PI3K-AKT-mTOR and MEK-ERK in 16 diagnostic and five relapsed T-ALL primary samples, and investigated the in vitro response of cells to Interleukin-7 (IL-7) and the inhibitor BEZ-235. T-ALL cells showed upregulated activity of the PI3K-AKT-mTOR and MEK-ERK pathways and increased expression of proliferation and translation markers. We found that perturbation induced by the ex vivo administration of either IL-7 or BEZ-235 reveals a high degree of exclusivity with respect to the phospho-protein responsiveness to these agents. Notably, these response signatures were maintained from diagnosis to relapse in individual patients. In conclusion, we demonstrated the power of mass cytometry single-cell profiling of signal transduction pathways in T-ALL. Taking advantage of this advanced approach, we were able to identify distinct clusters with different responsiveness to IL-7 and BEZ-235 that can persist at relapse. Collectively our observations can contribute to a better understanding of the complex signaling network governing T-ALL behavior and its correlation with influence on the response to therapy.

• MeSH
• dítě MeSH
• fosfatidylinositol-3-kinasy metabolismus   MeSH
• interleukin-7 * farmakologie   MeSH
• lidé MeSH
• lymfoblastická leukemie-lymfom z prekurzorových T-buněk * farmakoterapie   metabolismus   MeSH
• protoonkogenní proteiny c-akt metabolismus   MeSH
• recidiva MeSH
• T-lymfocyty metabolismus   MeSH
• TOR serin-threoninkinasy metabolismus   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Childhood T-cell acute lymphoblastic leukemia (T-ALL) still remains a therapeutic challenge due to relapses which are resistant to further treatment. L-asparaginase (ASNase) is a key therapy component in pediatric T-ALL and lower sensitivity of leukemia cells to this drug negatively influences overall treatment efficacy and outcome. PTEN protein deletion and/or activation of the PI3K/Akt signaling pathway leading to altered cell growth and metabolism are emerging as a common feature in T-ALL. We herein investigated the relationship amongst PTEN deletion, ASNase sensitivity and glucose metabolism in T-ALL cells. First, we found significant differences in the sensitivity to ASNase amongst T-ALL cell lines. While cell lines more sensitive to ASNase were PTEN wild type (WT) and had no detectable level of phosphorylated Akt (P-Akt), cell lines less sensitive to ASNase were PTEN-null with high P-Akt levels. Pharmacological inhibition of Akt in the PTEN-null cells rendered them more sensitive to ASNase and lowered their glycolytic function which then resembled PTEN WT cells. In primary T-ALL cells, although P-Akt level was not dependent exclusively on PTEN expression, their sensitivity to ASNase could also be increased by pharmacological inhibition of Akt. In summary, we highlight a promising therapeutic option for T-ALL patients with aberrant PTEN/PI3K/Akt signaling.

• MeSH
• asparaginasa * farmakologie   terapeutické užití   MeSH
• dítě MeSH
• fosfatidylinositol-3-kinasy * genetika   metabolismus   MeSH
• fosfohydroláza PTEN * genetika   metabolismus   MeSH
• lidé MeSH
• lymfoblastická leukemie-lymfom z prekurzorových T-buněk * farmakoterapie   genetika   metabolismus   MeSH
• protoonkogenní proteiny c-akt metabolismus   MeSH
• signální transdukce MeSH
• T-lymfocyty metabolismus   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The biology of T-cell acute lymphoblastic leukemia (ALL) is characterized by functional pre-T-cell receptor (TCR) signaling. Non-T-cell activation linker (NTAL) is a nonenzymatic transmembrane adaptor molecule that is involved in the proximal signaling of lymphocytes. In our previous work, we found an association between high NTAL expression in T-cell ALL blasts and a favorable response to initial glucocorticoid treatment. In the present study, we confirm our previous observation in an experimental model. In addition, the molecular mechanism of the contribution of NTAL to malignant T-cell ALL blast signaling and to methylprednisolone-induced cell death is analyzed. In the in vitro experiments, we used the T-cell ALL Jurkat cell line (Jurkat/wt) and derived Jurkat cell line with stable NTAL expression (Jurkat/NTAL(+)). Cell signaling and cell death after methylprednisolone treatment and after TCR stimulation were analyzed using flow cytometry, Western blot, and quantitative polymerase chain reaction. Jurkat/NTAL(+) cells are significantly more sensitive to both methylprednisolone treatment and TCR-induced stimulation. In addition, after TCR stimulation, Jurkat/NTAL(+) cells show a higher level of intracellular extracellular signal-regulated kinase 1/2 (ERK) phosphorylation and increased expression of the CD69 activation marker on the cell surface than the Jurkat/wt cells. The ERK inhibitor U0126 almost completely abrogates TCR-induced cell death and, importantly, reverses the sensitizing effect of the NTAL protein on methylprednisolone-induced cell death. In conclusion, NTAL acts as a tumor suppressor that enhances the proximal signaling of leukemic blasts. The key downstream molecule responsible for the biological effect of TCR signaling is ERK. Higher ERK phosphorylation leads to enhanced cell death after TCR stimulation and increases cell sensitivity to methylprednisolone-induced cell death.

• MeSH
• adaptorové proteiny signální transdukční fyziologie   MeSH
• apoptóza účinky léků   fyziologie   MeSH
• butadieny farmakologie   MeSH
• CD antigeny metabolismus   MeSH
• chemorezistence účinky léků   MeSH
• diferenciační antigeny T-lymfocytů metabolismus   MeSH
• fosforylace účinky léků   MeSH
• inhibitory proteinkinas farmakologie   MeSH
• Jurkat buňky účinky léků   enzymologie   MeSH
• lektiny typu C metabolismus   MeSH
• lidé MeSH
• lymfoblastická leukemie-lymfom z prekurzorových T-buněk metabolismus   patologie   MeSH
• MAP kinasový signální systém účinky léků   MeSH
• methylprednisolon farmakologie   MeSH
• mitogenem aktivovaná proteinkinasa 1 antagonisté a inhibitory   metabolismus   MeSH
• mitogenem aktivovaná proteinkinasa 3 antagonisté a inhibitory   metabolismus   MeSH
• nádorové proteiny antagonisté a inhibitory   fyziologie   MeSH
• nitrily farmakologie   MeSH
• posttranslační úpravy proteinů účinky léků   MeSH
• receptory antigenů T-buněk účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• techniky in vitro MeSH

The present study evaluated the pharmacokinetics of methotrexate (MTX, CAS 59-05-2) and 7-hydroxymethotrexate (7-OHMTX, CAS 5939-37-7) in children with acute lymphoblastic leukemia (ALL) with particular interest devoted to the renal excretion at the steady-state and to the relationships between total (CL) and renal clearances (CL(R)) of both compounds. Ten children (seven girls) aged 8.5 years (2.9-16) years with standard or medium-risk ALL received four 24-h i.v. infusions of high-dose MTX (HDMTX, 5 g/m2) with leucovorin (CAS 58-05-9) rescue according to the ALL-BFM-95 protocol. MTX and 7-OHMTX were assayed in plasma and urine by high-performance liquid chromatography. At the steady-state, the clearance (CL) of MTX (6.28 +/- 2.79 l h(-1)) was correlated with its CL(R) (r(s) = 0.79, p < 0.0001) which accounted for 61% (SD 26%) of the former. There were weak correlations between pretreatment values of creatinine clearance calculated using Schwartz's formula and the drug's CL (r(s) = 0.30, p < 0.05) or CLR (r(s) = 0.41, p < 0.02). In contrast, the CL(R) accounted for only 26% (SD 15%) of the metabolite's CL which was estimated assuming 10% conversion of MTX to 7-OHMTX. The CL values of both compounds were highly correlated (r(s) = 0.86, p < 0.0001). The CL(R) of the parent compound was on the average 9-fold higher (range: 3.5- to 17-fold) and was strongly correlated with the CL(R) of the metabolite (r(s) = 0.87, p < 0.0001). The ratio 7-OHMTX/MTX of urinary concentrations was between 2.4 and 9.8% with the mean value of 4.1%. This study suggests that during the 24-h i.v. infusions of HDMTX to children with ALL, the exposure of patients to 7-OHMTX can be reasonably well predicted from the knowledge of MTX concentrations. The steady-state renal CLs, total CLs as well as urinary concentrations of the parent compound and metabolite are highly correlated and the correlation of plasma concentrations is moderate. Therefore, it is unlikely that simultaneous evaluation of 7-OHMTX and MTX steady-state concentrations could improve the predictive performance of the latter towards the response or the risk of complications, although future larger studies should verify this conclusion.

• MeSH
• analýza rozptylu MeSH
• antimetabolity antitumorózní krev   farmakokinetika   moč   MeSH
• dítě MeSH
• intravenózní infuze MeSH
• lidé MeSH
• lymfoblastická leukemie-lymfom z prekurzorových T-buněk metabolismus   MeSH
• methotrexát analogy a deriváty   krev   farmakokinetika   moč   MeSH
• mladiství MeSH
• plocha pod křivkou MeSH
• poločas MeSH
• předškolní dítě MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH