The role of apoptosis repressor with a CARD domain (ARC) in the therapeutic resistance of renal cell carcinoma (RCC): the crucial role of ARC in the inhibition of extrinsic and intrinsic apoptotic signalling

Cell Communication and Signaling

Research

Marcia Gasis¹  Constanze Wiek²  Helmut Hanenberg³  Sebastian Heikaus⁴  Sarah Funke⁴  Csaba Mahotka⁴  Vanessa Nitsche⁴  Anna Liverts⁴  Viktoriya Zlachevska⁴  Csaba Toth⁵  Peter Schirmacher⁶ 

[1] Department of Neurology, Heinrich Heine University Hospital, Medical Faculty, Moorenstrasse 5, 40225, Düsseldorf, Germany;Department of Otorhinolaryngology, Head and Neck Surgery, Heinrich Heine University, Universitätsstrasse 1, 40225, Düsseldorf, Germany;Department of Otorhinolaryngology, Head and Neck Surgery, Heinrich Heine University, Universitätsstrasse 1, 40225, Düsseldorf, Germany;Department of Pediatrics, the Herman B. Wells Center for Pediatric Research 702 Barnhill Dr, 46202, Indianapolis, IN, USA;Institute of Pathology, Heinrich Heine University Hospital, Medical Faculty, Moorenstrasse 5, 40225, Düsseldorf, Germany;Institute of Pathology, Heinrich Heine University Hospital, Medical Faculty, Moorenstrasse 5, 40225, Düsseldorf, Germany;Institute of Pathology, University Hospital Heidelberg, Im Neuenheimer Feld 224, 69120, Heidelberg, Germany;Institute of Pathology, University Hospital Heidelberg, Im Neuenheimer Feld 224, 69120, Heidelberg, Germany;

关键词: ARC;    Apoptosis;    Bcl-2 family;    renal cell carcinoma (RCC);    ABT-263;    TRAIL;   

DOI  :  10.1186/s12964-017-0170-5

 received in 2016-11-11, accepted in 2017-03-21,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundRenal cell carcinomas (RCCs) display broad resistance against conventional radio- and chemotherapies, which is due at least in part to impairments in both extrinsic and intrinsic apoptotic pathways. One important anti-apoptotic factor that is strongly overexpressed in RCCs and known to inhibit both apoptotic pathways is ARC (apoptosis repressor with a CARD domain).MethodsExpression and subcellular distribution of ARC in RCC tissue samples and RCC cell lines were determined by immunohistochemistry and fluorescent immunohistochemistry, respectively. Extrinsic and intrinsic apoptosis signalling were induced by TRAIL (TNF-related apoptosis-inducing ligand), ABT-263 or topotecan. ARC knock-down was performed in clearCa-12 cells using lentiviral transduction of pGIPZ. shRNAmir constructs. Extrinsic respectively intrinsic apoptosis were induced by TRAIL (TNF-related apoptosis-inducing ligand), ABT263 or topotecan. Potential synergistic effects were tested by pre-treatment with topotecan and subsequent treatment with ABT263. Activation of different caspases and mitochondrial depolarisation (JC-1 staining) were analysed by flow cytometry. Protein expression of Bcl-2 family members and ARC in RCC cell lines was measured by Western blotting. Statistical analysis was performed by Student’s t-test.ResultsRegarding the extrinsic pathway, ARC knockdown strongly enhanced TRAIL-induced apoptosis by increasing the activation level of caspase-8. Regarding the intrinsic pathway, ARC, which was only weakly expressed in the nuclei of RCCs in vivo, exerted its anti-apoptotic effect by impairing mitochondrial activation rather than inhibiting p53. Topotecan- and ABT-263-induced apoptosis was strongly enhanced following ARC knockdown in RCC cell lines. In addition, topotecan pre-treatment enhanced ABT-263-induced apoptosis and this effect was amplified in ARC-knockdown cells.ConclusionTaken together, our results are the first to demonstrate the importance of ARC protein in the inhibition of both the extrinsic and intrinsic pathways of apoptosis in RCCs. In this context, ARC cooperates with anti-apoptotic Bcl-2 family members to exert its strong anti-apoptotic effects and is therefore an important factor not only in the therapeutic resistance but also in future therapy strategies (i.e., Bcl-2 inhibitors) in RCC. In sum, targeting of ARC may enhance the therapeutic response in combination therapy protocols.

【 授权许可】

CC BY   
© The Author(s). 2017