Dual blockade of PI3K/AKT/mTOR (NVP-BEZ235) and Ras/Raf/MEK (AZD6244) pathways synergistically inhibit growth of primary endometrioid endometrial carcinoma cultures, whereas NVP-BEZ235 reduces tumor growth in the corresponding xenograft models.
OBJECTIVE
Endometrial carcinoma (EC) is the most common gynecological cancer in the Western World. Treatment options are limited for advanced and recurrent disease. Therefore, new treatment options are necessary. Inhibition of the PI3K/AKT/mTOR and/or the Ras/Raf/MEK pathways is suggested to be clinically relevant. However, the knowledge about the effect of combination targeted therapy in EC is limited. The aim of this study was to investigate the effect of these therapies on primary endometrioid EC cell cultures in vitro and in vivo.


METHODS
Primary endometrioid EC cell cultures were incubated with Temsirolimus (mTORC1 inhibitor), NVP-BKM120 (pan-PI3K inhibitor), NVP-BEZ235 (pan-PI3K/mTOR inhibitor), or AZD6244 (MEK1/2 inhibitor) as single treatment. In vitro, the effect of NVP-BEZ235 with or without AZD6244 was determined for cell viability, cell cycle arrest, apoptosis induction, and cell signaling. In vivo, the effect of NVP-BEZ35 was investigated for 2 subcutaneous xenograft models of the corresponding primary cultures.


RESULTS
NVP-BEZ235 was the most potent PI3K/AKT/mTOR pathway inhibitor. NVP-BEZ235 and AZD6244 reduced cell viability and induced cell cycle arrest and apoptosis, by reduction of p-AKT, p-S6, and p-ERK levels. Combination treatment showed a synergistic effect. In vivo, NVP-BEZ235 reduced tumor growth and inhibited p-S6 expression. The effects of the compounds were independent of the mutation profile of the cell cultures used.


CONCLUSIONS
A synergistic antitumor effect was shown for NVP-BEZ235 and AZD6244 in primary endometrioid EC cells in vitro. In addition, NVP-BEZ235 induced reduction of tumor growth in vivo. Therefore, targeted therapies seem an interesting strategy to further evaluate in clinical trials.
KU Leuven - University of Leuven, University Hospitals Leuven, Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, B-3000 Leuven, Belgium. Electronic address: Stefanie.Schrauwen@med.kuleuven.be.
Stefanie
S
Schrauwen
KU Leuven - University of Leuven, University Hospitals Leuven, Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, B-3000 Leuven, Belgium; KU Leuven, Department of Oncology, Laboratory for Translational Genetics, B-3000 Leuven, Belgium; VIB, Vesalius Research Center (VRC), B-3000 Leuven, Belgium. Electronic address: Jeroen.Depreeuw@vib-kuleuven.be.
Jeroen
J
Depreeuw
KU Leuven - University of Leuven, University Hospitals Leuven, Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, B-3000 Leuven, Belgium. Electronic address: coenegracthslieve@hotmail.com.
Lieve
L
Coenegrachts
KU Leuven - University of Leuven, University Hospitals Leuven, Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, B-3000 Leuven, Belgium. Electronic address: Els.Hermans@uzleuven.be.
Els
E
Hermans
KU Leuven, Department of Oncology, Laboratory for Translational Genetics, B-3000 Leuven, Belgium; VIB, Vesalius Research Center (VRC), B-3000 Leuven, Belgium. Electronic address: Diether.Lambrechts@vib-kuleuven.be.
Diether
D
Lambrechts
KU Leuven - University of Leuven, University Hospitals Leuven, Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, B-3000 Leuven, Belgium. Electronic address: Frederic.Amant@uzleuven.be.
Frédéric
F
Amant
D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D001562:Benzimidazoles / Q000008:administration & dosage / Q000494:pharmacology*; D018269:Carcinoma, Endometrioid / Q000188:drug therapy* / Q000201:enzymology; D004357:Drug Synergism; D016889:Endometrial Neoplasms / Q000188:drug therapy* / Q000201:enzymology; D005260:Female; D006801:Humans; D007093:Imidazoles / Q000008:administration & dosage / Q000494:pharmacology*; D020930:MAP Kinase Kinase Kinases / Q000037:antagonists & inhibitors; D020935:MAP Kinase Signaling System / Q000187:drug effects; D051379:Mice; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D051057:Proto-Oncogene Proteins c-akt / Q000037:antagonists & inhibitors / Q000378:metabolism; D011804:Quinolines / Q000008:administration & dosage / Q000494:pharmacology*; D058570:TOR Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays; D048490:raf Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D018631:ras Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism
D001562:Benzimidazoles; D007093:Imidazoles; D020930:MAP Kinase Kinase Kinases; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D051057:Proto-Oncogene Proteins c-akt; D011804:Quinolines; D058570:TOR Serine-Threonine Kinases; D048490:raf Kinases; D018631:ras Proteins; C517975:AZD 6244; C546842:MTOR protein, human; C531198:dactolisib
AZD6244; Endometrioid endometrial cancer; NVP-BEZ235; Primary cell culture; Targeted therapy