The novel BH3 α-helix mimetic JY-1-106 induces apoptosis in a subset of cancer cells (lung cancer, colon cancer and mesothelioma) by disrupting Bcl-xL and Mcl-1 protein–protein interactions with Bak

Molecular Cancer

Research

Paul T Wilder¹  Wenbo Yu²  Kenno Vanommeslaeghe²  Jeremy L Yap²  Kwan-Young Jung²  Steven Fletcher³  Alexander D MacKerell³  Chander Peddaboina⁴  Dan Jupitor⁴  Roy W Smythe⁴  Arun Rai⁴  M Karen Newell-Rogers⁴  Weihua Jiang⁴  Xiaobo Cao⁴  Harry T Papaconstantinou⁴  Richard P Tubin⁴ 

[1] Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 108 N. Greene St., 21201, Baltimore, MD, USA;Department of Pharmaceutical Science, University of Maryland School of Pharmacy, 20 N. Pine St., 21201, Baltimore, MD, USA;Department of Pharmaceutical Science, University of Maryland School of Pharmacy, 20 N. Pine St., 21201, Baltimore, MD, USA;University of Maryland Marlene and Stewart Greenebaum Cancer Center, 22 S. Greene St., 21201, Baltimore, MD, USA;Department of Surgery, Scott & White Memorial Hospital and Clinic, The Texas A&M University System, Health Science Center, College of Medicine, 702 SW HK Dodgen Loop, 76504, Temple, Texas, USA;

关键词: Mcl-1;    Bcl-xL;    Small molecule inhibitor;    Cancer;    BH3 mimetic;   

DOI  :  10.1186/1476-4598-12-42

 received in 2013-02-20, accepted in 2013-05-02,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundIt has been shown in many solid tumors that the overexpression of the pro-survival Bcl-2 family members Bcl-2/Bcl-xL and Mcl-1 confers resistance to a variety of chemotherapeutic agents. We designed the BH3 α-helix mimetic JY-1-106 to engage the hydrophobic BH3-binding grooves on the surfaces of both Bcl-xL and Mcl-1.MethodsJY-1-106–protein complexes were studied using molecular dynamics (MD) simulations and the SILCS methodology. We have evaluated the in vitro effects of JY-1-106 by using a fluorescence polarization (FP) assay, an XTT assay, apoptosis assays, and immunoprecipitation and western-blot assays. A preclinical human cancer xenograft model was used to test the efficacy of JY-1-106 in vivo.ResultsMD and SILCS simulations of the JY-1-106–protein complexes indicated the importance of the aliphatic side chains of JY-1-106 to binding and successfully predicted the improved affinity of the ligand for Bcl-xL over Mcl-1. Ligand binding affinities were measured via an FP assay using a fluorescently labeled Bak-BH3 peptide in vitro. Apoptosis induction via JY-1-106 was evidenced by TUNEL assay and PARP cleavage as well as by Bax–Bax dimerization. Release of multi-domain Bak from its inhibitory binding to Bcl-2/Bcl-xL and Mcl-1 using JY-1-106 was detected via immunoprecipitation (IP) western blotting.At the cellular level, we compared the growth proliferation IC50s of JY-1-106 and ABT-737 in multiple cancer cell lines with various Bcl-xL and Mcl-1 expression levels. JY-1-106 effectively induced cell death regardless of the Mcl-1 expression level in ABT-737 resistant solid tumor cells, whilst toxicity toward normal human endothelial cells was limited. Furthermore, synergistic effects were observed in A549 cells using a combination of JY-1-106 and multiple chemotherapeutic agents. We also observed that JY-1-106 was a very effective agent in inducing apoptosis in metabolically stressed tumors. Finally, JY-1-106 was evaluated in a tumor-bearing nude mouse model, and was found to effectively repress tumor growth. Strong TUNEL signals in the tumor cells demonstrated the effectiveness of JY-1-106 in this animal model. No significant side effects were observed in mouse organs after multiple injections.ConclusionsTaken together, these observations demonstrate that JY-1-106 is an effective pan-Bcl-2 inhibitor with very promising clinical potential.

【 授权许可】

Unknown   
© Cao et al.; licensee BioMed Central Ltd. 2013. 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.