The therapeutic potential of targeting PI3K/AKT/PTEN signalling in B-cell malignancies remains attractive. Whilst PI3K-α/δ inhibitors demonstrate clinical benefit in certain B-cell lymphomas, PI3K signalling inhibitors have been inadequate in relapsed/refractory diffuse large B-cell lymphoma (DLBCL) in part, due to treatment related toxicities. Clinically, AKT inhibitors exhibit a differentiated tolerability profile offering an alternative approach for treating patients with B-cell malignancies. To explore how AKT inhibition complements other potential therapeutics in the treatment of DLBCL patients, an in vitro combination screen was conducted across a panel of DLCBL cell lines. The AKT inhibitor, capivasertib, in combination with the BCL-2 inhibitor, venetoclax, produced notable therapeutic benefit in preclinical models of DLBCL. Capivasertib and venetoclax rapidly induced caspase and PARP cleavage in GCB-DLBCL PTEN wildtype cell lines and those harbouring PTEN mutations or reduced PTEN protein, driving prolonged tumour growth inhibition in DLBCL cell line and patient derived xenograft lymphoma models. The addition of the rituximab further deepened the durability of capivasertib and venetoclax responses in a RCHOP refractory DLBCL in vivo models. These findings provide preclinical evidence for the rational treatment combination of AKT and BCL-2 inhibitors using capivasertib and venetoclax respectively alongside anti-CD20 antibody supplementation for treatment of patients with DLBCL.

• MeSH
• apoptóza účinky léků   MeSH
• bicyklické sloučeniny heterocyklické * farmakologie   terapeutické užití   MeSH
• difúzní velkobuněčný B-lymfom * farmakoterapie   patologie   MeSH
• fosfohydroláza PTEN metabolismus   MeSH
• lidé MeSH
• myši SCID MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• proliferace buněk účinky léků   MeSH
• protokoly protinádorové kombinované chemoterapie * farmakologie   terapeutické užití   MeSH
• protoonkogenní proteiny c-akt * metabolismus   MeSH
• protoonkogenní proteiny c-bcl-2 * antagonisté a inhibitory   metabolismus   MeSH
• pyrimidiny * farmakologie   terapeutické užití   MeSH
• pyrroly farmakologie   terapeutické užití   MeSH
• rituximab farmakologie   terapeutické užití   MeSH
• sulfonamidy * farmakologie   terapeutické užití   MeSH
• xenogenní modely - testy protinádorové aktivity * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• BCL2 protein, human MeSH Prohlížeč
• bicyklické sloučeniny heterocyklické * MeSH
• capivasertib MeSH Prohlížeč
• fosfohydroláza PTEN MeSH
• protoonkogenní proteiny c-akt * MeSH
• protoonkogenní proteiny c-bcl-2 * MeSH
• pyrimidiny * MeSH
• pyrroly MeSH
• rituximab MeSH
• sulfonamidy * MeSH
• venetoclax MeSH Prohlížeč

Activated B-cell-like diffuse large B-cell lymphoma (ABC-DLBCL) is driven by aberrant activation of the B-cell receptor (BCR) and the TLR/MyD88 signaling pathways. The heat-shock protein HSP110 is a candidate for their regulation as it stabilizes MyD88. However, its role in overall BCR signaling remains unknown. Here, we used first-in-class HSP110 inhibitors to address this question. HSP110 inhibitors decreased the survival of several ABC-DLBCL cell lines in vitro and in vivo, and reduced the phosphorylation of BCR signaling kinases, including BTK and SYK. We identified an interaction between HSP110 and SYK and demonstrated that HSP110 promotes SYK phosphorylation. Finally, the combination of the HSP110 inhibitor with the PI3K inhibitor copanlisib decreases SYK/BTK and AKT phosphorylation synergistically, leading to suppression of tumor growth in cell line xenografts and strong reduction in patient-derived xenografts. In conclusion, by regulating the BCR/TLR signaling pathway, HSP110 inhibitors are potential drug candidates for ABC-DLBCL patients.

• MeSH
• chinazoliny MeSH
• difúzní velkobuněčný B-lymfom * farmakoterapie   metabolismus   patologie   MeSH
• fosforylace účinky léků   MeSH
• kinasa Syk * antagonisté a inhibitory   metabolismus   MeSH
• lidé MeSH
• myši SCID MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádorové buňky kultivované MeSH
• proteiny tepelného šoku HSP110 * metabolismus   MeSH
• pyrimidiny farmakologie   MeSH
• receptory antigenů B-buněk * metabolismus   MeSH
• signální transdukce * účinky léků   MeSH
• xenogenní modely - testy protinádorové aktivity * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chinazoliny MeSH
• copanlisib MeSH Prohlížeč
• kinasa Syk * MeSH
• proteiny tepelného šoku HSP110 * MeSH
• pyrimidiny MeSH
• receptory antigenů B-buněk * MeSH
• SYK protein, human MeSH Prohlížeč

Venetoclax (VEN), a B-cell lymphoma 2 (BCL2) inhibitor, has a promising single-agent activity in mantle cell lymphoma (MCL), acute lymphoblastic leukemia (ALL), and large BCLs, but remissions were generally short, which call for rational drug combinations. Using a panel of 21 lymphoma and leukemia cell lines and 28 primary samples, we demonstrated strong synergy between VEN and A1155463, a BCL-XL inhibitor. Immunoprecipitation experiments and studies on clones with knockout of expression or transgenic expression of BCL-XL confirmed its key role in mediating inherent and acquired VEN resistance. Of note, the VEN and A1155463 combination was synthetically lethal even in the cell lines with lack of expression of the proapoptotic BCL2L11/BIM and in the derived clones with genetic knockout of BCL2L11/BIM. This is clinically important because BCL2L11/BIM deletion, downregulation, or sequestration results in VEN resistance. Immunoprecipitation experiments further suggested that the proapoptotic effector BAX belongs to principal mediators of the VEN and A1155463 mode of action in the BIM-deficient cells. Lastly, the efficacy of the new proapoptotic combination was confirmed in vivo on a panel of 9 patient-derived lymphoma xenografts models including MCL (n = 3), B-ALL (n = 2), T-ALL (n = 1), and diffuse large BCL (n = 3). Because continuous inhibition of BCL-XL causes thrombocytopenia, we proposed and tested an interrupted 4 days on/3 days off treatment regimen, which retained the desired antitumor synergy with manageable platelet toxicity. The proposed VEN and A1155463 combination represents an innovative chemotherapy-free regimen with significant preclinical activity across diverse BCL2+ hematologic malignancies irrespective of the BCL2L11/BIM status.

• MeSH
• apoptóza účinky léků   MeSH
• benzothiazoly MeSH
• bicyklické sloučeniny heterocyklické * farmakologie   terapeutické užití   MeSH
• chemorezistence * MeSH
• isochinoliny MeSH
• lidé MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• protein bcl-X * metabolismus   antagonisté a inhibitory   MeSH
• protein BCL2L11 * metabolismus   genetika   MeSH
• protinádorové látky farmakologie   terapeutické užití   MeSH
• protoonkogenní proteiny c-bcl-2 metabolismus   antagonisté a inhibitory   MeSH
• sulfonamidy * farmakologie   terapeutické užití   MeSH
• synergismus léků MeSH
• xenogenní modely - testy protinádorové aktivity MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• A-1155463 MeSH Prohlížeč
• BCL2L1 protein, human MeSH Prohlížeč
• benzothiazoly MeSH
• bicyklické sloučeniny heterocyklické * MeSH
• isochinoliny MeSH
• protein bcl-X * MeSH
• protein BCL2L11 * MeSH
• protinádorové látky MeSH
• protoonkogenní proteiny c-bcl-2 MeSH
• sulfonamidy * MeSH
• venetoclax MeSH Prohlížeč