We have located links that may give you full text access.
Targeting cancer cells and tumor microenvironment in preclinical and clinical models of Hodgkin lymphoma using the dual PI3Kδ/γ inhibitor RP6530.
Clinical Cancer Research 2018 October 24
PURPOSE: Tumor-associated macrophages (TAMs) and the hyperactivation of phosphoinositide 3-kinase(PI3K)/AKT pathway are involved in the pathogenesis of Hodgkin lymphoma (HL) and affect disease outcome. Since the δ and γ isoforms of PI3K are overexpressed in Hodgkin/Reed-Sternberg (HRS) cells and the tumor microenvironment (TME), we propose that the PI3Kδ/γ inhibitor RP6530 might affect both HRS cells and TME, ultimately leading to an enhanced antitumor response.
EXPERIMENTAL DESIGN: HL cell lines (L-540, KM-H2 and L-428) and primary human macrophages were used to investigate the activity of RP6530 in vitro and in vivo in HL cell line xenografts.
RESULTS: In vitro , RP6530 besides killing and inhibiting the proliferation of HL cells, downregulated lactic acid metabolism, switching the activation of macrophages from an immunosuppressive M2-like phenotype to a more inflammatory M1-like state. By RNA sequencing, we define tumor glycolysis as a specific PI3Kδ/γ-dependent pathway implicated in the metabolic reprogramming of cancer cells. We identify the metabolic regulator Pyruvate Kinase M2 (PKM2) as the main mediator of tumor-induced immunosuppressive phenotype of macrophages. Furthermore, we show in human tumor xenografts that RP6530 repolarizes TAMs into pro-inflammatory macrophages and inhibits tumor vasculature, leading to tumor regression. Interestingly, HL patients experiencing objective responses (CR and PR) in a phase 1 trial using RP6530 showed a significant inhibition of circulating MDSCs and an average mean reduction in serum TARC levels of 40% (range, 4-76%).
CONCLUSIONS: Our results support PI3Kδ/γ inhibition as a novel therapeutic strategy that targets both malignant cells and the TME to treat HL patients.
EXPERIMENTAL DESIGN: HL cell lines (L-540, KM-H2 and L-428) and primary human macrophages were used to investigate the activity of RP6530 in vitro and in vivo in HL cell line xenografts.
RESULTS: In vitro , RP6530 besides killing and inhibiting the proliferation of HL cells, downregulated lactic acid metabolism, switching the activation of macrophages from an immunosuppressive M2-like phenotype to a more inflammatory M1-like state. By RNA sequencing, we define tumor glycolysis as a specific PI3Kδ/γ-dependent pathway implicated in the metabolic reprogramming of cancer cells. We identify the metabolic regulator Pyruvate Kinase M2 (PKM2) as the main mediator of tumor-induced immunosuppressive phenotype of macrophages. Furthermore, we show in human tumor xenografts that RP6530 repolarizes TAMs into pro-inflammatory macrophages and inhibits tumor vasculature, leading to tumor regression. Interestingly, HL patients experiencing objective responses (CR and PR) in a phase 1 trial using RP6530 showed a significant inhibition of circulating MDSCs and an average mean reduction in serum TARC levels of 40% (range, 4-76%).
CONCLUSIONS: Our results support PI3Kδ/γ inhibition as a novel therapeutic strategy that targets both malignant cells and the TME to treat HL patients.
Full text links
Related Resources
Trending Papers
Heart failure with preserved ejection fraction: diagnosis, risk assessment, and treatment.Clinical Research in Cardiology : Official Journal of the German Cardiac Society 2024 April 12
Proximal versus distal diuretics in congestive heart failure.Nephrology, Dialysis, Transplantation 2024 Februrary 30
Efficacy and safety of pharmacotherapy in chronic insomnia: A review of clinical guidelines and case reports.Mental Health Clinician 2023 October
World Health Organization and International Consensus Classification of eosinophilic disorders: 2024 update on diagnosis, risk stratification, and management.American Journal of Hematology 2024 March 30
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app
All material on this website is protected by copyright, Copyright © 1994-2024 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.
By using this service, you agree to our terms of use and privacy policy.
Your Privacy Choices
You can now claim free CME credits for this literature searchClaim now
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app