Metformin produces growth inhibitory effects in combination with nutlin-3a on malignant mesothelioma through a cross-talk between mTOR and p53 pathways

BMC Cancer

Research Article

Takao Namiki¹  Ikuo Sekine²  Kenzo Hiroshima³  Koichiro Tatsumi⁴  Yuji Tada⁴  Kengo Shimazu⁵  Hideaki Shimada⁶  Takao Morinaga⁷  Masatoshi Tagawa⁸  Masato Shingyoji⁹ 

[1] Department of Japanese-Oriental Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, 260-8670, Chiba, Japan;Department of Medical Oncology, Faculty of Medicine, University of Tsukuba, Tennodai 1-1-1, Ibaragi, 305-8575, Tsukuba, Japan;Department of Pathology, Tokyo Women’s Medical University Yachiyo Medical Center, 477-96 Ohwadashinden, Yachiyo, 276-8524, Chiba, Japan;Department of Respirology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, 260-8670, Chiba, Japan;Department of Respirology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, 260-8670, Chiba, Japan;Division of Pathology and Cell Therapy, Chiba Cancer Center Research Institute, 666-2 Nitona, Chuo-ku, 260-8717, Chiba, Japan;Department of Japanese-Oriental Medicine, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, 260-8670, Chiba, Japan;Department of Surgery, School of Medicine, Toho University, 6-11-1 Oomori-nishi, Oota-ku, 143-8541, Tokyo, Japan;Division of Pathology and Cell Therapy, Chiba Cancer Center Research Institute, 666-2 Nitona, Chuo-ku, 260-8717, Chiba, Japan;Division of Pathology and Cell Therapy, Chiba Cancer Center Research Institute, 666-2 Nitona, Chuo-ku, 260-8717, Chiba, Japan;Department of Molecular Biology and Oncology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, 260-8670, Chiba, Japan;Division of Respirology, Chiba Cancer Center, 666-2 Nitona, Chuo-ku, 260-8717, Chiba, Chiba, Japan;

关键词: Mesothelioma;    Metformin;    Nutlin-3a;    p53;    Mammalian target of rapamycin;   

DOI  :  10.1186/s12885-017-3300-y

 received in 2016-08-20, accepted in 2017-04-25,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundMesothelioma is resistant to conventional treatments and is often defective in p53 pathways. We then examined anti-tumor effects of metformin, an agent for type 2 diabetes, and combinatory effects of metformin and nutlin-3a, an inhibitor for ubiquitin-mediated p53 degradation, on human mesothelioma.MethodsWe examined the effects with a colorimetric assay and cell cycle analyses, and investigated molecular events in cells treated with metformin and/or nutlin-3a with Western blot analyses. An involvement of p53 was tested with siRNA for p53.ResultsMetformin suppressed cell growth of 9 kinds of mesothelioma including immortalized cells of mesothelium origin irrespective of the p53 functional status, whereas susceptibility to nutlin-3a was partly dependent on the p53 genotype. We investigated combinatory effects of metformin and nutlin-3a on, nutlin-3a sensitive MSTO-211H and NCI-H28 cells and insensitive EHMES-10 cells, all of which had the wild-type p53 gene. Knockdown of p53 expression with the siRNA demonstrated that susceptibility of MSTO-211H and NCI-H28 cells to nutlin-3a was p53-dependent, whereas that of EHMES-10 cells was not. Nevertheless, all the cells treated with both agents produced additive or synergistic growth inhibitory effects. Cell cycle analyses also showed that the combination increased sub-G1 fractions greater than metformin or nutlin-3a alone in MSTO-211H and EHMES-10 cells. Western blot analyses showed that metformin inhibited downstream pathways of the mammalian target of rapamycin (mTOR) but did not activate the p53 pathways, whereas nutlin-3a phosphorylated p53 and suppressed mTOR pathways. Cleaved caspase-3 and conversion of LC3A/B were also detected but it was dependent on cells and treatments. The combination of both agents in MSTO-211H cells rather suppressed the p53 pathways that were activated by nutrin-3a treatments, whereas the combination rather augmented the p53 actions in NCI-H28 and EHMES-10 cells.ConclusionThese data collectively indicated a possible interactions between mTOR and p53 pathways, and the combinatory effects were attributable to differential mechanisms induced by a cross-talk between the pathways.

【 授权许可】

CC BY   
© The Author(s). 2017