GS-1101 (CAL-101) is an oral PI3Kδ-specific inhibitor that has shown preclinical and clinical activity in non-Hodgkin lymphoma and chronic lymphocytic leukemia. To investigate the potential role of PI3Kδ in Hodgkin lymphoma (HL), we screened 5 HL cell lines and primary samples from patients with HL for PI3Kδ isoform expression and constitutive PI3K pathway activation. Inhibition of PI3Kδ by GS-1101 resulted in the inhibition of Akt phosphorylation. Cocultures with stroma cells induced Akt activation in HL cells, and this effect was blocked by GS-1101. Conversely, production of the stroma-stimulating chemokine, CCL5, by HL cells was reduced by GS-1101. GS-1101 also induced dose-dependent apoptosis of HL cells at 48 hours. Reductions in cell viability and apoptosis were enhanced when combining GS-1101 with the mTOR inhibitor everolimus. Our findings suggest that excessive PI3Kδ activity is characteristic in HL and support clinical evaluation of GS-1101, alone and in combination, as targeted therapy for HL.
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http://dx.doi.org/10.1182/blood-2011-10-386763 | DOI Listing |
Br J Haematol
January 2025
Department of Medicine and Surgery, University of Insubria, Varese, Italy.
Allogeneic hematopoietic stem cell transplantation (alloHSCT) remains an option for young and fit chronic lymphocytic leukaemia (CLL) patients with high-risk disease features. However, allotransplanted patients are generally excluded from clinical trials, making data regarding the use of venetoclax after alloHSCT extremely rare. We report data from 7 CLL patients who received venetoclax after alloHSCT among 53 Italian centers.
View Article and Find Full Text PDFClin Cancer Res
December 2024
University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States.
Purpose: Although the B-cell receptor (BCR) signal plays a critical role in CLL cell survival and a target of current therapies (ibrutinib targets Bruton's tyrosine kinase; idelalisib targets PI3Kδ), contribution of the cytokine-driven JAK2 pathway to the "CLL cell-survival signaling network" is largely undefined.
Experimental Design: CLL patients were enrolled to investigate expression/activation of JAK2 and acylglycerol kinase (AGK), and their functional implication in primary CLL cell survival. A series of biochemical and molecular biology assays were employed to uncover the underlying mechanism.
Int J Mol Sci
October 2024
NeuroAllergy Research Laboratory (NARL), School of Life and Environmental Sciences, Faculty of Science, Engineering and Built Environment, Deakin University, 75 Pigdons Road, Geelong, VIC 3216, Australia.
Neuroinflammation, characterised by the activation of immune cells in the central nervous system (CNS), plays a dual role in both protecting against and contributing to the progression of neurodegenerative diseases, such as Alzheimer's disease (AD) and multiple sclerosis (MS). This review explores the role of phosphoinositide 3-kinase (PI3K), a key enzyme involved in cellular survival, proliferation, and inflammatory responses, within the context of neuroinflammation. Two PI3K isoforms of interest, PI3Kγ and PI3Kδ, are specific to the regulation of CNS cells, such as microglia, astrocytes, neurons, and oligodendrocytes, influencing pathways, such as Akt, mTOR, and NF-κB, that control cytokine production, immune cell activation, and neuroprotection.
View Article and Find Full Text PDFAnn Hematol
November 2024
Hematology Department, Hôpital Pitié Salpêtrière APHP, Sorbonne University, Paris, France.
We present the 6-year update of a phase 2 study evaluating the combination of obinutuzumab and idelalisib in relapse/refractory Waldenstrom macroglobulinemia. The results of the REMODEL trial demonstrated interesting efficacy in a high-risk genotype profile population. The primary endpoint was achieved with a median PFS of 25.
View Article and Find Full Text PDFExp Hematol Oncol
November 2024
First Faculty of Medicine, BIOCEV, Charles University, Prumyslova 595, Prague, 25250, Czech Republic.
The phosphatidylinositol 3‑kinase/protein kinase B (PI3K/AKT) signaling pathway is critically active in many cell types, both normal and neoplastic. Many small-molecule inhibitors targeting different levels of the PI3K/AKT pathway have been developed for cancer therapy, but their efficacy is reduced by compensatory pathway re-activation mechanisms, and their tolerability by toxic side effects. We studied this problem using cell lines representing diffuse large B-cell lymphoma (SUDHL-4 and OCI-Ly7), a genetically-encoded live-cell reporter of AKT activity, and 3 small-molecule inhibitors targeting different levels of the pathway: idelalisib (PI3Kδ), GSK2334470 (PDPK1), and ipatasertib (AKT).
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