Novel synergistic antitumor effects of rapamycin with bortezomib on hepatocellular carcinoma cells and orthotopic tumor model

BMC Cancer

Research Article

Lu Sun¹  Xiaonan Kang¹  Kai Jiang¹  Hong Shu²  Kun Guo²  Dongmei Gao²  Yan Li²  Weizhong Wu²  Cun Wang³  Guangzhi Jin³  Haiyan Sun³  Chun Sun³  Yinkun Liu³ 

[1] Institutes of Biomedical Sciences, Fudan University, 200032, Shanghai, China;Liver Cancer Institute, Zhongshan Hospital, Fudan University, Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, 200032, Shanghai, China;Liver Cancer Institute, Zhongshan Hospital, Fudan University, Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, 200032, Shanghai, China;Institutes of Biomedical Sciences, Fudan University, 200032, Shanghai, China;

关键词: Rapamycin;    Bortezomib;    mTOR;    Akt;    Hepatocellular carcinoma;   

DOI  :  10.1186/1471-2407-12-166

 received in 2012-02-08, accepted in 2012-05-04,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundDespite recent advances in the treatment of hepatocellular carcinoma (HCC), the chemotherapy efficacy against HCC is still unsatisfactory. The mammalian target of rapamycin (mTOR) has been emerged as an important cancer therapeutic target. However, HCC cells often resistant to rapamycin because of the paradoxical activation of Akt by rapamycin. In this study, we investigated whether bortezomib could enhance the antitumor effects of rapamycin.MethodsThe effects of rapamycin and bortezomib on HCC proliferation, apoptosis, migration, and invasiveness in vitro were assessed by CCK-8 analysis, flow cytometry, Hoechst 33342 staining and transwell assays, respectively. Total and phosphorylated protein levels of Akt were detected by Western blotting. The effects of rapamycin and/or bortezomib on the mRNA expression levels of p53, p27, p21 and Bcl-2 family in HCCLM3 cells were evaluated by RT-PCR. The roles of rapamycin and bortezomib on HCC growth and metastasis in xenograft models were evaluated by tumor volumes and fluorescent signals. The effects of rapamycin and bortezomib on cell proliferation and apoptosis in vivo were test by PCNA and TUNEL staining.ResultsBortezomib synergized with rapamycin to reduce cell growth, induce apoptosis, and inhibit cell mobility in vitro. Further mechanistic studies showed that bortezomib inhibited rapamycin-induced phosphorylated Akt, which in turn enhanced apoptosis of HCC cell lines. The alteration of the mRNA expression of cell cycle inhibitors p53, p27, p21 and apoptosis associated genes Bcl-2, Bax were also involved in the synergistic antitumor effects of rapamycin and bortezomib. P53 inhibitor PFT-α significantly attenuate the effect of rapamycin and bortezomib on cell apoptosis, which indicated that the pro-apoptotic effect of rapamycin and bortezomib may be p53-dependent. Treatment of HCCLM3-R bearing nude mice with rapamycin and bortezomib significantly enhanced tumor growth inhibition (72.4%), comparing with either rapamycin- (54.7%) or bortezomib-treated mice (22.4%). In addition, the lung metastasis was significantly suppressed in mice received the combination treatment (16.6%). The combination treatment of rapamycin and bortezomib significantly inhibited tumor cell proliferation and tumor angiogenesis in vivo.ConclusionThe combination of rapamycin with bortezomib could be a novel and promising therapeutic approach to the treatment of HCC.

【 授权许可】

Unknown   
© Wang et al.; licensee BioMed Central Ltd. 2012. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.