Bruton tyrosine kinase (BTK) inhibitor therapy induces peripheral blood lymphocytosis in chronic lymphocytic leukemia (CLL), which lasts for several months. It remains unclear whether nongenetic adaptation mechanisms exist, allowing CLL cells' survival during BTK inhibitor-induced lymphocytosis and/or playing a role in therapy resistance. We show that in approximately 70% of CLL cases, ibrutinib treatment in vivo increases Akt activity above pretherapy levels within several weeks, leading to compensatory CLL cell survival and a more prominent lymphocytosis on therapy. Ibrutinib-induced Akt phosphorylation (pAktS473) is caused by the upregulation of Forkhead box protein O1 (FoxO1) transcription factor, which induces expression of Rictor, an assembly protein for the mTORC2 protein complex that directly phosphorylates Akt at serine 473 (S473). Knockout or inhibition of FoxO1 or Rictor led to a dramatic decrease in Akt phosphorylation and growth disadvantage for malignant B cells in the presence of ibrutinib (or PI3K inhibitor idelalisib) in vitro and in vivo. The FoxO1/Rictor/pAktS473 axis represents an early nongenetic adaptation to B cell receptor (BCR) inhibitor therapy not requiring PI3Kδ or BTK kinase activity. We further demonstrate that FoxO1 can be targeted therapeutically and its inhibition induces CLL cells' apoptosis alone or in combination with BTK inhibitors (ibrutinib, acalabrutinib, pirtobrutinib) and blocks their proliferation triggered by T cell factors (CD40L, IL-4, and IL-21).
- MeSH
- adenin * analogy a deriváty farmakologie MeSH
- chronická lymfatická leukemie * farmakoterapie metabolismus genetika patologie MeSH
- forkhead box protein O1 * metabolismus genetika MeSH
- fosforylace MeSH
- lidé MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- nádorové proteiny metabolismus genetika MeSH
- piperidiny * farmakologie MeSH
- protein RICTOR * genetika metabolismus MeSH
- proteinkinasa BTK metabolismus genetika antagonisté a inhibitory MeSH
- protoonkogenní proteiny c-akt * metabolismus genetika MeSH
- pyrazoly * farmakologie MeSH
- pyrimidiny * farmakologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Several in vitro models have been developed to mimic chronic lymphocytic leukemia (CLL) proliferation in immune niches; however, they typically do not induce robust proliferation. We prepared a novel model based on mimicking T-cell signals in vitro and in patient-derived xenografts (PDXs). Six supportive cell lines were prepared by engineering HS5 stromal cells with stable expression of human CD40L, IL4, IL21, and their combinations. Co-culture with HS5 expressing CD40L and IL4 in combination led to mild CLL cell proliferation (median 7% at day 7), while the HS5 expressing CD40L, IL4, and IL21 led to unprecedented proliferation rate (median 44%). The co-cultures mimicked the gene expression fingerprint of lymph node CLL cells (MYC, NFκB, and E2F signatures) and revealed novel vulnerabilities in CLL-T-cell-induced proliferation. Drug testing in co-cultures revealed for the first time that pan-RAF inhibitors fully block CLL proliferation. The co-culture model can be downscaled to five microliter volume for large drug screening purposes or upscaled to CLL PDXs by HS5-CD40L-IL4 ± IL21 co-transplantation. Co-transplanting NSG mice with purified CLL cells and HS5-CD40L-IL4 or HS5-CD40L-IL4-IL21 cells on collagen-based scaffold led to 47% or 82% engraftment efficacy, respectively, with ~20% of PDXs being clonally related to CLL, potentially overcoming the need to co-transplant autologous T-cells in PDXs.
- MeSH
- buňky stromatu * metabolismus patologie MeSH
- chronická lymfatická leukemie * patologie genetika farmakoterapie MeSH
- inhibitory proteinkinas farmakologie MeSH
- interleukiny genetika metabolismus MeSH
- kokultivační techniky * MeSH
- lidé MeSH
- ligand CD40 * metabolismus genetika MeSH
- myši MeSH
- proliferace buněk * MeSH
- T-lymfocyty imunologie metabolismus MeSH
- xenogenní modely - testy antitumorózní aktivity MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Recirculation of chronic lymphocytic leukemia (CLL) cells between the peripheral blood and lymphoid niches plays a critical role in disease pathophysiology, and inhibiting this process is one of the major mechanisms of action for B-cell receptor (BCR) inhibitors such as ibrutinib and idelalisib. Migration is a complex process guided by chemokine receptors and integrins. However, it remains largely unknown how CLL cells integrate multiple migratory signals while balancing survival in the peripheral blood and the decision to return to immune niches. Our study provided evidence that CXCR4/CD5 intraclonal subpopulations can be used to study the regulation of migration of CLL cells. We performed RNA profiling of CXCR4dimCD5bright vs CXCR4brightCD5dim CLL cells and identified differential expression of dozens of molecules with a putative function in cell migration. GRB2-associated binding protein 1 (GAB1) positively regulated CLL cell homing capacity of CXCR4brightCD5dim cells. Gradual GAB1 accumulation in CLL cells outside immune niches was mediated by FoxO1-induced transcriptional GAB1 activation. Upregulation of GAB1 also played an important role in maintaining basal phosphatidylinositol 3-kinase (PI3K) activity and the "tonic" AKT phosphorylation required to sustain the survival of resting CLL B cells. This finding is important during ibrutinib therapy, because CLL cells induce the FoxO1-GAB1-pAKT axis, which represents an adaptation mechanism to the inability to home to immune niches. We have demonstrated that GAB1 can be targeted therapeutically by novel GAB1 inhibitors, alone or in combination with BTK inhibition. GAB1 inhibitors induce CLL cell apoptosis, impair cell migration, inhibit tonic or BCR-induced AKT phosphorylation, and block compensatory AKT activity during ibrutinib therapy.
- MeSH
- adaptorové proteiny signální transdukční biosyntéza MeSH
- adenin analogy a deriváty farmakologie MeSH
- chronická lymfatická leukemie farmakoterapie metabolismus patologie MeSH
- forkhead box protein O1 metabolismus MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- piperidiny farmakologie MeSH
- pohyb buněk * MeSH
- protoonkogenní proteiny c-akt metabolismus MeSH
- regulace genové exprese u leukemie * MeSH
- signální transdukce * MeSH
- upregulace * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Publikační typ
- abstrakt z konference MeSH
- Publikační typ
- abstrakt z konference MeSH
Although methotrexate (MTX) is the most well-known antifolate included in many standard therapeutic regimens, substantial toxicity limits its wider use, particularly in pediatric oncology. Our study focused on a detailed analysis of MTX effects in cell lines derived from two types of pediatric solid tumors: medulloblastoma and osteosarcoma. The main aim of this study was to analyze the effects of treatment with MTX at concentrations comparable to MTX plasma levels in patients treated with high-dose or low-dose MTX. The results showed that treatment with MTX significantly decreased proliferation activity, inhibited the cell cycle at S-phase and induced apoptosis in Daoy and Saos-2 reference cell lines, which were found to be MTX-sensitive. Furthermore, no difference in these effects was observed following treatment with various doses of MTX ranging from 1 to 40 µM. These findings suggest the possibility of achieving the same outcome with the application of low-dose MTX, an extremely important result, particularly for clinical practice. Another important aspect of treatment with high-dose MTX in clinical practice is the administration of leucovorin (LV) as an antidote to reduce MTX toxicity in normal cells. For this reason, the combined application of MTX and LV was also included in our experiments; however, this application of MTX together with LV did not elicit any detectable effect. The expression analysis of genes involved in the mechanisms of resistance to MTX was a final component of our study, and the results helped us to elucidate the mechanisms of the various responses to MTX among the cell lines included in our study.
- MeSH
- antagonisté kyseliny listové aplikace a dávkování MeSH
- chemorezistence genetika MeSH
- dihydrofolátreduktasa metabolismus MeSH
- lidé MeSH
- meduloblastom * enzymologie genetika MeSH
- methotrexát aplikace a dávkování MeSH
- nádorové buněčné linie MeSH
- nádory kostí * enzymologie genetika MeSH
- nádory mozečku * enzymologie genetika MeSH
- osteosarkom * enzymologie genetika MeSH
- polymerázová řetězová reakce s reverzní transkripcí MeSH
- proliferace buněk účinky léků MeSH
- průtoková cytometrie MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Publikační typ
- abstrakt z konference MeSH
Metotrexát, strukturální analog kyseliny listové, je jedním z nejčastěji používaných chemoterapeutik především pro léčbu hematoonkologických onemocnění, solidních nádorů, ale také některých autoimunitních poruch. Primárně metotrexát narušuje folátový metabolizmus inhibicí dihydrofolátreduktázy, což má za následek potlačení syntézy pyrimidinových a purinových prekurzorů. Nedostatek stavebních kamenů nukleových kyselin se pak odráží v cytostatickém, cytotoxickém a diferenciačním efektu metotrexátu. Mezi další procesy, které jsou ovlivněny inhibicí folátového metabolizmu, patří metylace biomolekul, především proteinů a DNA. Metotrexát však působí na metabolické dráhy a buněčné procesy i nezávisle na metabolizmu folátů. Na základě podobnosti struktury metotrexátu a funkčních skupin některých inhibitorů histondeacetyláz bylo predikováno a poté i experimentálně potvrzeno, že metotrexát má schopnost inhibovat histondeacetylázy. Dále byla prokázána schopnost metotrexátu účinně ovlivňovat glyoxalázový a antioxidační systém. I když je metotrexát používán jako folátový antagonista v protinádorové terapii více než 60 let, odhalování jeho dalších cílů působení na molekulární i buněčné úrovni stále pokračuje.
Methotrexate, a structural analogue of folic acid, is one of the most frequently used chemotherapeutics, especially in haematological malignancies, various solid tumours and also inflammatory disorders. Methotrexate interferes with folate metabolism, mainly by inhibition of dihydrofolate reductase, resulting in the suppression of purine and pyrimidine precursor synthesis. The depletion of nucleic acid precursors seems to be responsible for the cytostatic, cytotoxic and differentiation effects of methotrexate. Methylation of biomolecules represents another folate-dependent pathway that is also affected by methotrexate. Furthermore, methotrexate is able to modify metabolic pathways and cellular processes independently of folate metabolism. Based on the similar structure of methotrexate and of functional groups of certain histone deacetylase inhibitors, the ability of methotrexate to inhibit histone deacetylases was predicted and consequently verified. Recently published findings also suggest that methotrexate affects glyoxalase and antioxidant systems. Although methotrexate has been used as a folate metabolism antagonist in anticancer therapy for more than 60 years, the identification of its’ other molecular targets in cellular metabolism still continues.
- Klíčová slova
- oxidativní stres, glyoxalázový systém, inhibitory histondeacetylázy, dihydrofolátreduktáza, folátový metabolizmus,
- MeSH
- antagonisté kyseliny listové farmakologie MeSH
- apoptóza účinky léků MeSH
- buněčná smrt účinky léků MeSH
- dihydrofolátreduktasa účinky léků MeSH
- inhibitory histondeacetylas MeSH
- kyselina listová metabolismus MeSH
- laktoylglutathionlyasa účinky léků MeSH
- lidé MeSH
- methotrexát * farmakologie MeSH
- metylace DNA účinky léků MeSH
- metylace MeSH
- nádory farmakoterapie MeSH
- oxidační stres účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
