Cytotoxic effects of 15-deoxy-Δ12,14-prostaglandin J2 alone and in combination with dasatinib against uterine sarcoma in vitro

Effective chemotherapeutic strategies for uterine sarcoma are lacking; existing therapies achieve poor response rates. Previous studies have identified the prostaglandin 15-deoxy- Δ12,14-prostaglandin J2 (15d-PGJ2) as a potential anticancer treatment; however, its effectiveness in uterine sarcoma has not been examined. Furthermore, the molecular mechanisms underlying the cytotoxic mechanism of 15d-PGJ2 remain unclear. Here, we evaluated the effects of 15d-PGJ2 alone and in combination with the tyrosine kinas inhibitor (TKI) dasatinib in uterine sarcoma cell lines (MES-SA, MES-SA/DX5 and SKN). 15d-PGJ2 inhibited cell growth and increased apoptosis. Western blotting demonstrated that 15d-PGJ2 treatment increased MEK and ERK phosphorylation, and decreased levels of phosphorylated AKT. Dasatinib in combination with 15d-PGJ2 significantly reduced cell proliferation compared with 15d-PGJ2 alone, and repressed both the AKT and MAPK pathways. The cell growth inhibition rate in the PGJ2 was 21.5±12.0, 35.3±5.4 and 28.3±4.2%, respectively (MES-SA, MES-SA/DX5 and SKN cell lines) and the cell growth inhibition rate in the combination therapy was significantly higher compared with 15d-PGJ2 alone (MES-SA; 64.2±0.8, MES-SA/DX5;23.9±8.2 and SKN; 41.4±17.6%). The PGJ2 IC50 determined by MTT assay was 27.41,10.46 and 17.38 μmol/l, respectively (MES-SA, MES-SA/DX5 and SKN cell lines) and the dasatinib IC50 was 6.68,17.30 and 6.25 μmol/l, respectively. Our findings demonstrate that 15d-PGJ2 suppresses proliferation by inactivating the AKT pathway in uterine sarcoma. Furthermore, combining 15d-PGJ2 with dasatinib produced a synergistic effect on cancer cell inhibition by repressing 15d-PGJ2-mediated activation of MAPK signaling, and further repressing AKT signaling. These results suggest that 15d-PGJ2 could be used in combination with dasatinib as a potential therapeutic approach for uterine sarcoma.

内容要旨・審査要旨・論文本文の公開：
内容要旨・審査要旨：LID201705191007.pdf
論文本文：LID201706261001.pdf
本論文は，著者TAKAKO KAWAKITAの学位論文として提出され，学位審査・授与の対象となっている。
著者の申請により要約(2017-05-19公開)に替えて論文全文を公開(2017-06-26)

© Kawakita et al. This is an open access article distributed under the terms of Creative Commons Attribution License (https://creativecommons.org/licenses/by-nc-nd/4.0/).