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

Diffuse large B-cell lymphoma (DLBCL) is an aggressive disease that exhibits constitutive activation of phosphoinositide 3-kinase (PI3K) driven by chronic B-cell receptor signaling or PTEN deficiency. Since pan-PI3K inhibitors cause severe side effects, we investigated the anti-lymphoma efficacy of the specific PI3Kβ/δ inhibitor AZD8186. We identified a subset of DLBCL models within activated B-cell-like (ABC) and germinal center B-cell-like (GCB) DLBCL that were sensitive to AZD8186 treatment. On the molecular level, PI3Kβ/δ inhibition decreased the pro-survival NF-κB and AP-1 activity or led to downregulation of the oncogenic transcription factor MYC. In AZD8186-resistant models, we detected a feedback activation of the PI3K/AKT/mTOR pathway following PI3Kβ/δ inhibition, which limited AZD8186 efficacy. The combined treatment with AZD8186 and the mTOR inhibitor AZD2014 overcame resistance to PI3Kβ/δ inhibition and completely prevented outgrowth of lymphoma cells in vivo in cell line- and patient-derived xenograft mouse models. Collectively, our study reveals that subsets of DLBCLs are addicted to PI3Kβ/δ signaling and thus identifies a previously unappreciated role of the PI3Kβ isoform in DLBCL survival. Furthermore, our data demonstrate that combined targeting of PI3Kβ/δ and mTOR is effective in all major DLBCL subtypes supporting the evaluation of this strategy in a clinical trial setting.

• MeSH
• difúzní velkobuněčný B-lymfom * patologie   MeSH
• fosfatidylinositol-3-kinasy * metabolismus   MeSH
• lidé MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• signální transdukce MeSH
• TOR serin-threoninkinasy metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• AZD8186 MeSH Prohlížeč
• fosfatidylinositol-3-kinasy * MeSH
• MTOR protein, human MeSH Prohlížeč
• TOR serin-threoninkinasy MeSH