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Lin F, de Gooijer MC, Hanekamp D, Chandrasekaran G, Buil LCM, Thota N, Sparidans RW, Beijnen JH, Würdinger T, van Tellingen O. PI3K-mTOR Pathway Inhibition Exhibits Efficacy Against High-grade Glioma in Clinically Relevant Mouse Models. Clin Cancer Res 2016; 23:1286-1298. [PMID: 27553832 DOI: 10.1158/1078-0432.ccr-16-1276] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 08/08/2016] [Accepted: 08/17/2016] [Indexed: 11/16/2022]
Abstract
Purpose: The PI3K-AKT-mTOR signaling pathway is frequently activated in glioblastoma and offers several druggable targets. However, clinical efficacy of PI3K/mTOR inhibitors in glioblastoma has not yet been demonstrated. Insufficient drug delivery may limit the efficacy of PI3K/mTOR inhibitors against glioblastoma. The presence of the efflux transporters ABCB1/Abcb1 (P-glycoprotein, MDR1) and ABCG2/Abcg2 (BCRP) at the blood-brain barrier (BBB) restricts the brain penetration of many drugs.Experimental Design: We used in vitro drug transport assays and performed pharmacokinetic/pharmacodynamic studies in wild-type and ABC-transporter knockout mice. The efficacy of PI3K-mTOR inhibition was established using orthotopic allograft and genetically engineered spontaneous glioblastoma mouse models.Results: The mTOR inhibitors rapamycin and AZD8055 are substrates of ABCB1, whereas the dual PI3K/mTOR inhibitor NVP-BEZ235 and the PI3K inhibitor ZSTK474 are not. Moreover, ABCG2 transports NVP-BEZ235 and AZD8055, but not ZSTK474 or rapamycin. Concordantly, Abcb1a/b-/-;Abcg2-/- mice revealed increased brain penetration of rapamycin (13-fold), AZD8055 (7.7-fold), and NVP-BEZ235 (4.5-fold), but not ZSTK474 relative to WT mice. Importantly, ABC transporters limited rapamycin brain penetration to subtherapeutic levels, while the reduction in NVP-BEZ235 brain penetration did not prevent target inhibition. NVP-BEZ235 and ZSTK474 demonstrated antitumor efficacy with improved survival against U87 orthotopic gliomas, although the effect of ZSTK474 was more pronounced. Finally, ZSTK474 prolonged overall survival in Cre-LoxP conditional transgenic Pten;p16Ink4a/p19Arf;K-Rasv12;LucR mice, mainly by delaying tumor onset.Conclusions: PI3K/mTOR inhibitors with weak affinities for ABC transporters can achieve target inhibition in brain (tumors), but have modest single-agent efficacy and combinations with (BBB penetrable) inhibitors of other activated pathways may be required. Clin Cancer Res; 23(5); 1286-98. ©2016 AACR.
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Affiliation(s)
- Fan Lin
- Department of Bio-Pharmacology/Mouse Cancer Clinic, The Netherlands Cancer Institute (Antoni van Leeuwenhoek Hospital), Amsterdam, the Netherlands
| | - Mark C de Gooijer
- Department of Bio-Pharmacology/Mouse Cancer Clinic, The Netherlands Cancer Institute (Antoni van Leeuwenhoek Hospital), Amsterdam, the Netherlands
| | - Diana Hanekamp
- Department of Bio-Pharmacology/Mouse Cancer Clinic, The Netherlands Cancer Institute (Antoni van Leeuwenhoek Hospital), Amsterdam, the Netherlands
| | - Gayathri Chandrasekaran
- Department of Bio-Pharmacology/Mouse Cancer Clinic, The Netherlands Cancer Institute (Antoni van Leeuwenhoek Hospital), Amsterdam, the Netherlands
| | - Levi C M Buil
- Department of Bio-Pharmacology/Mouse Cancer Clinic, The Netherlands Cancer Institute (Antoni van Leeuwenhoek Hospital), Amsterdam, the Netherlands
| | - Nishita Thota
- Department of Bio-Pharmacology/Mouse Cancer Clinic, The Netherlands Cancer Institute (Antoni van Leeuwenhoek Hospital), Amsterdam, the Netherlands
| | - Rolf W Sparidans
- Department of Pharmacy and Pharmacology, The Netherlands Cancer Institute/Slotervaart Hospital, Amsterdam, the Netherlands
| | - Jos H Beijnen
- Department of Pharmacy and Pharmacology, The Netherlands Cancer Institute/Slotervaart Hospital, Amsterdam, the Netherlands.,Faculty of Science, Department of Pharmaceutical Sciences, Division of Pharmacoepidemiology & Clinical Pharmacology, Utrecht University, Utrecht, the Netherlands
| | - Tom Würdinger
- Neuro-oncology Research Group, Departments of Neurosurgery and Pediatric Oncology/Hematology, Cancer Center Amsterdam, VU University Medical Center, Amsterdam, the Netherlands.,Molecular Neurogenetics Unit, Departments of Neurology and Radiology, Massachusetts General Hospital, and Neuroscience Program, Harvard Medical School, Boston, Massachusetts
| | - Olaf van Tellingen
- Department of Bio-Pharmacology/Mouse Cancer Clinic, The Netherlands Cancer Institute (Antoni van Leeuwenhoek Hospital), Amsterdam, the Netherlands.
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Fecher LA, Amaravadi RK, Schuchter LM, Flaherty KT. Drug targeting of oncogenic pathways in melanoma. Hematol Oncol Clin North Am 2009; 23:599-618, x. [PMID: 19464605 DOI: 10.1016/j.hoc.2009.03.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Melanoma continues to be one of the most aggressive and morbid malignancies once metastatic. Overall survival for advanced unresectable melanoma has not changed over the past several decades. However, the presence of some long-term survivors of metastatic melanoma highlights the heterogeneity of this disease and the potential for improved outcomes. Current research is uncovering the molecular and genetic scaffolding of normal and aberrant cell function. The known oncogenic pathways in melanoma and the attempts to develop therapy for them are discussed. The targeting of certain cellular processes, downstream of the common genetic alterations, for which the issues of target and drug validation are somewhat distinct, are also highlighted.
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Affiliation(s)
- Leslie A Fecher
- Department of Medicine, Division of Hematology and Oncology, Abramson Cancer Center, University of Pennsylvania, 3400 Spruce Street, 16 Penn Tower, Philadelphia, PA 19104, USA.
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