Antitumor activity and induction of TP53-dependent apoptosis toward ovarian clear cell adenocarcinoma by the dual PI3K/mTOR inhibitor DS-7423

Tomoko Kashiyama; Katsutoshi Oda; Yuji Ikeda; Yoshinobu Shiose; Yasuhide Hirota; Kanako Inaba; Chinami Makii; Reiko Kurikawa; Aki Miyasaka; Takahiro Koso; Tomohiko Fukuda; Michihiro Tanikawa; Keiko Shoji; Kenbun Sone; Takahide Arimoto; Osamu Wada-Hiraike; Kei Kawana; Shunsuke Nakagawa; Koichi Matsuda; Frank McCormick; Hiroyuki Aburatani; Tetsu Yano; Yutaka Osuga; Tomoyuki Fujii

doi:10.1371/journal.pone.0087220

Antitumor activity and induction of TP53-dependent apoptosis toward ovarian clear cell adenocarcinoma by the dual PI3K/mTOR inhibitor DS-7423

PLoS One. 2014 Feb 4;9(2):e87220. doi: 10.1371/journal.pone.0087220. eCollection 2014.

Authors

Tomoko Kashiyama¹, Katsutoshi Oda¹, Yuji Ikeda¹, Yoshinobu Shiose², Yasuhide Hirota², Kanako Inaba¹, Chinami Makii¹, Reiko Kurikawa¹, Aki Miyasaka¹, Takahiro Koso¹, Tomohiko Fukuda¹, Michihiro Tanikawa¹, Keiko Shoji¹, Kenbun Sone¹, Takahide Arimoto¹, Osamu Wada-Hiraike¹, Kei Kawana¹, Shunsuke Nakagawa³, Koichi Matsuda⁴, Frank McCormick⁵, Hiroyuki Aburatani⁶, Tetsu Yano⁷, Yutaka Osuga¹, Tomoyuki Fujii¹

Affiliations

¹ Department of Obstetrics and Gynecology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan.
² Oncology Research Laboratories, Daiichi Sankyo Co. Ltd., Tokyo, Japan.
³ Department of Obstetrics and Gynecology, Faculty of Medicine, Teikyo University, Tokyo, Japan.
⁴ Laboratory of Molecular Medicine, Human Genome Center, Institute of Medical Science, The University of Tokyo, Tokyo, Japan.
⁵ Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, California, United States of America.
⁶ Genome Science Division, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan.
⁷ Department of Obstetrics and Gynecology, National Center for Global Health and Medicine, Tokyo, Japan.

Abstract

DS-7423, a novel, small-molecule dual inhibitor of phosphatidylinositol-3-kinase (PI3K) and mammalian target of rapamycin (mTOR), is currently in phase I clinical trials for solid tumors. Although DS-7423 potently inhibits PI3Kα (IC50 = 15.6 nM) and mTOR (IC50 = 34.9 nM), it also inhibits other isoforms of class I PI3K (IC50 values: PI3Kβ = 1,143 nM; PI3Kγ = 249 nM; PI3Kδ = 262 nM). The PI3K/mTOR pathway is frequently activated in ovarian clear cell adenocarcinomas (OCCA) through various mutations that activate PI3K-AKT signaling. Here, we describe the anti-tumor effect of DS-7423 on a panel of nine OCCA cell lines. IC50 values for DS-7423 were <75 nM in all the lines, regardless of the mutational status of PIK3CA. In mouse xenograft models, DS-7423 suppressed the tumor growth of OCCA in a dose-dependent manner. Flow cytometry analysis revealed a decrease in S-phase cell populations in all the cell lines and an increase in sub-G1 cell populations following treatment with DS-7423 in six of the nine OCCA cell lines tested. DS-7423-mediated apoptosis was induced more effectively in the six cell lines without TP53 mutations than in the three cell lines with TP53 mutations. Concomitantly with the decreased phosphorylation level of MDM2 (mouse double minute 2 homolog), the level of phosphorylation of TP53 at Ser46 was increased by DS-7423 in the six cell lines with wild-type TP53, with induction of genes that mediate TP53-dependent apoptosis, including p53AIP1 and PUMA at 39 nM or higher doses. Our data suggest that the dual PI3K/mTOR inhibitor DS-7423 may constitute a promising molecular targeted therapy for OCCA, and that its antitumor effect might be partly obtained by induction of TP53-dependent apoptosis in TP53 wild-type OCCAs.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adenocarcinoma, Clear Cell / drug therapy
Adenocarcinoma, Clear Cell / enzymology
Adenocarcinoma, Clear Cell / genetics
Adenocarcinoma, Clear Cell / pathology*
Animals
Antineoplastic Agents / pharmacology*
Antineoplastic Agents / therapeutic use
Apoptosis / drug effects*
Apoptosis Regulatory Proteins / metabolism
Cell Line, Tumor
Cell Proliferation / drug effects
Class I Phosphatidylinositol 3-Kinases
DNA Mutational Analysis
Female
Flow Cytometry
Gene Expression Regulation, Neoplastic / drug effects
Humans
Mice, Nude
Ovarian Neoplasms / drug therapy
Ovarian Neoplasms / enzymology
Ovarian Neoplasms / genetics
Ovarian Neoplasms / pathology*
Phosphatidylinositol 3-Kinases / metabolism
Phosphoinositide-3 Kinase Inhibitors*
Phosphorylation / drug effects
Phosphoserine / metabolism
Protein Kinase Inhibitors / pharmacology*
Protein Kinase Inhibitors / therapeutic use
RNA, Messenger / genetics
RNA, Messenger / metabolism
Signal Transduction / drug effects
Signal Transduction / genetics
Sirolimus / pharmacology
TOR Serine-Threonine Kinases / antagonists & inhibitors*
TOR Serine-Threonine Kinases / metabolism
Tumor Suppressor Protein p53 / metabolism
Xenograft Model Antitumor Assays

Substances

Antineoplastic Agents
Apoptosis Regulatory Proteins
P53AIP1 protein, human
Phosphoinositide-3 Kinase Inhibitors
Protein Kinase Inhibitors
RNA, Messenger
Tumor Suppressor Protein p53
Phosphoserine
MTOR protein, human
Class I Phosphatidylinositol 3-Kinases
PIK3CA protein, human
TOR Serine-Threonine Kinases
Sirolimus

Grants and funding

This work was supported by Daiichi Sankyo Co. Ltd., The Grant-in-Aid for Scientific Research (C), Grant Number 19599005 and 23592437 from the Ministry of Education, Culture, Sports, Science and Technology of Japan (to K Oda). This study was also performed as a research program of the Project for Development of Innovative Research on Cancer Therapeutics (P-Direct), Ministry of Education, Culture, Sports, Science and Technology of Japan (to T Yano). Yoshinobu Shiose and Yasuhide Hirota, employees of Daiichi Sankyo Co. Ltd, contributed to the experiments (in vivo experiments) as listed in the “contributions” of each author. The funders themselves had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.