PI3K inhibitors remain an option for some relapsed indolent lymphomas and chronic lymphocytic leukemia, but their widespread use may be limited by adverse effects.
Altogether, these results underline the key role of PI3K/AKT pathway in the generation of the CLL proliferative pool and provide additional rationale for the usage of PI3K inhibitors.
Areas covered: Herein, we review PI3K isoforms and their inhibitors in general, and duvelisib in particular; examine literature on preclinical investigations, pharmacokinetics and clinical studies of duvelisib either as single agent or in combination, for patients with CLL and other lymphoid malignancies.
Areas covered: This review highlights key aspects of BTK, PI3K and BCL-2 inhibitors that are currently at various stages of preclinical and clinical development in CLL.
CLL cell death upon CK2 inhibition is mediated by inactivation of PKC, a PI3K downstream target, and correlates with increased PTEN activity, indicating that CK2 promotes CLL cell survival at least in part via PI3K-dependent signaling.
Collectively, these data demonstrate that CLL metabolism, especially OCR, is linked to prognostic factors and is curbed by BCR and PI3K pathway inhibition.<b>Implications:</b> This study identifies a relationship between oxidative phosphorylation in CLL and prognostic factors providing a rationale to therapeutically target these processes.<i></i>.
Considering the importance of the PI3K/AKT pathway in mediating survival and antiapoptotic signals in the B-cell types of chronic lymphocytic leukaemia (CLL) and acute lymphoblastic leukaemia (ALL), we sequenced the AKT1 exon 3 for the above mentioned mutation in 87 specimens, representing 45 CLLs, 38 ALLs and 4 prolymphocytic leukaemia (PLL) cases, which are all of B-cell origin.
Currently, inhibitors of kinases like BTK or PI3K blocking BCR signaling, and molecules that mimic the BH3 domain to compete with BCL-2 are established tools in the treatment of CLL.
Dysregulation of signaling pathways, such as B cell receptor , toll-like receptor, PI3K, nuclear factor κB, notch signaling pathway, Wnt/Fzd signaling pathway, and Hedgehog and Janus kinases/signal transducers and activators of transcription signaling pathway, as the terminal events of the aberrant gene expression and the pro-survival effects of microenvironment, plays a crucial role in the process of CLL. miRNAs, a novel found noncoding RNA, which regulate gene expression at transcription or post-transcription level and correlate with pathogenesis of CLL provide us new avenues to better evaluating prognosis and therapy of it.
Furthermore, addition of caffeine or Idelalisib to activated CLL cells significantly inhibited phosphorylation of AKT, a downstream kinase of PI3K, but did not affect CLL viability.
Genome-wide expression profiling of in vitro Mφ- and CD40L-stimulated CLL cells indicated activation of the phosphoinositide 3-kinase (PI3K)-V-Akt murine thymoma viral oncogene homolog (AKT)-mammalian target of rapamycin (mTOR) pathway, which was confirmed in ex vivo CLL LN material.
Here, we demonstrate that the class I phosphoinositide 3-kinase (PI3K) catalytic subunit p110δ is essential for CLL-derived macrophages to respond to therapeutic antibodies.
Here, we examined the mechanism by which the cyclic-AMP/PDE4 signaling axis suppresses PI3K, toward identifying a novel mechanism-based combinatorial strategy to attack BCR-dependency in mature B-cell malignancies.<b>Experimental Design:</b> We used <i>in vitro</i> and <i>in vivo</i> diffuse large B-cell lymphoma (DLBCL) cell lines and primary chronic lymphocytic leukemia (CLL) samples to preclinically evaluate the effects of the combination of the FDA-approved phosphodiesterase 4 (PDE4) inhibitor roflumilast and idelalisib on cell survival and tumor growth.
Idelalisib is a PI3Kδ inhibitor that has been approved for the treatment of lymphoma and chronic lymphocytic leukemia in the relapsed/refractory setting, and several other PI3K inhibitors are being developed targeting other isoforms of the PI3K enzyme, which results in distinct toxicities and variable efficacy in the clinical setting.
Idelalisib was the first PI3K inhibitor approved by the US Food and Drug Administration and is utilized in the treatment of relapsed/refractory chronic lymphocytic leukemia/small lymphocytic lymphoma and follicular lymphoma.
In chronic lymphocytic leukemia (CLL) and non-Hodgkin lymphomas (NHLs), B-cell receptor signaling leads to activation of the phosphatidylinositol 3-kinase (PI3K) pathway.
In conclusion, we characterize for the first time EZH2 target genes in CLL revealing a hitherto unknown implication of EZH2 in modulating the PI3K pathway in a non-canonical, PRC2-independent way, with potential therapeutic implications considering that PI3K inhibitors are effective therapeutic agents for CLL.
Perhaps because of the central role played by PI3K in BCR signaling, B cell leukemia and lymphomas are the first diseases for which a PI3K inhibitor has been approved for clinical use.