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Indexed by:期刊论文

Date of Publication:2013-05-14

Journal:BRITISH JOURNAL OF CANCER

Included Journals:SCIE、PubMed、Scopus

Volume:108

Issue:9

Page Number:1870-1878

ISSN No.:0007-0920

Key Words:Bcl-2 phosphorylation; S1; BH3 mimetics; antileukaemic

Abstract:Background: Bcl-2-like members have been found to be inherently overexpressed in many types of haematologic malignancies. The small-molecule S1 is a BH3 mimetic and a triple inhibitor of Bcl-2, Mcl-1 and Bcl-XL.
   Methods: The lethal dose 50 (LD50) values of S1 in five leukaemic cell lines and 41 newly diagnosed leukaemia samples were tested. The levels of Bcl-2 family members and phosphorylated Bcl-2 were semiquantitatively measured by western blotting. The interactions between Bcl-2 family members were tested by co-immunoprecipitation. The correlation between the LD50 and expression levels of Bcl-2 family members, alone or in combination, was analysed.
   Results: S1 exhibited variable sensitivity with LD50 values ranging >2 logs in both established and primary leukaemic cells. The ratio of pBcl-2/(Bcl-2 + Mcl-1) could predict the S1 response. Furthermore, we demonstrated that pBcl-2 antagonised S1 by sequestering the Bak and Bim proteins that were released from Mcl-1, andpBcl-2/Bak, pBcl-2/Bax and pBcl-2/Bim complexes cannot be disrupted by S1.
   Conclusion: A predictive index was obtained for the novel BH3 mimetic S1. The shift of proapoptotic proteins from being complexed with Mcl-1 to being complexed with pBcl-2 was revealed for the first time, which is the mechanism underlying the index value described herein.