Blocking XIAP:CASP7-p19 selectively induces apoptosis of CASP3/DR malignancies by a novel reversible small molecule

Abstract X-linked inhibitor of apoptosis (XIAP) inhibits caspases 3, 7, and 9, thereby preventing cell apoptosis. Endogenous Second mitochondria-derived activator of caspase (Smac) competes out the binding of caspases with XIAP and causes apoptosis, so that Smac mimetics are under clinical trials fo...

Full description

Saved in:
Bibliographic Details
Main Authors: Shih-Hsun Chen, Szu-Ying Wu, Yun-Xun Chang, En-Ning Lui, Chih-Kang Chang, Sheng-Wei Lin, Michael Hsiao, Jinn-Moon Yang, Po-Huang Liang
Format: Article
Language:English
Published: Nature Publishing Group 2025-06-01
Series:Cell Death and Disease
Online Access:https://doi.org/10.1038/s41419-025-07774-y
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849685829027364864
author Shih-Hsun Chen
Szu-Ying Wu
Yun-Xun Chang
En-Ning Lui
Chih-Kang Chang
Sheng-Wei Lin
Michael Hsiao
Jinn-Moon Yang
Po-Huang Liang
author_facet Shih-Hsun Chen
Szu-Ying Wu
Yun-Xun Chang
En-Ning Lui
Chih-Kang Chang
Sheng-Wei Lin
Michael Hsiao
Jinn-Moon Yang
Po-Huang Liang
author_sort Shih-Hsun Chen
collection DOAJ
description Abstract X-linked inhibitor of apoptosis (XIAP) inhibits caspases 3, 7, and 9, thereby preventing cell apoptosis. Endogenous Second mitochondria-derived activator of caspase (Smac) competes out the binding of caspases with XIAP and causes apoptosis, so that Smac mimetics are under clinical trials for anti-cancer chemotherapy. We demonstrated by selectively alkylating caspase 7 (CASP7) to release the active CASP7 for killing the drug-resistant cancer cells with accumulated XIAP:CASP7 resulted from caspase-3 down-regulation (CASP3/DR). However, finding a reversible inhibitor of the protein-protein interaction (PPI) poses a significant challenge. Here, we identified a reversible XIAP:CASP7 inhibitor, 643943, through a multiple-mode virtual screening strategy. In vitro experiments revealed that 643943 bound to CASP7, released the linker-BIR2 domain of XIAP, and activated the caspase. Removing an essential hydroxyl group on 643943 or replacing the OH-interacting Asp93 on CASP7 caused loss of 643943 cytotoxicity, revealing the binding mode. This compound thus selectively killed MCF-7 and other CASP3/DR triple-negative breast cancer cell lines, but not the cancer and normal cell lines expressing higher levels of CASP3 in vitro and in vivo. Moreover, 643943 overcame chemoresistance via down-regulating β-catenin and its associated ABC transporters in paclitaxel-resistant MCF-7 cells. Our studies not only serve as a proof-of-concept for using XIAP:CASP7 as a drug target, but also provide the first reversible XIAP:CASP7 inhibitor for cancer therapy of CASP3/DR malignancies.
format Article
id doaj-art-965d455fb220466db5354ffc956f0ff5
institution DOAJ
issn 2041-4889
language English
publishDate 2025-06-01
publisher Nature Publishing Group
record_format Article
series Cell Death and Disease
spelling doaj-art-965d455fb220466db5354ffc956f0ff52025-08-20T03:22:57ZengNature Publishing GroupCell Death and Disease2041-48892025-06-0116111310.1038/s41419-025-07774-yBlocking XIAP:CASP7-p19 selectively induces apoptosis of CASP3/DR malignancies by a novel reversible small moleculeShih-Hsun Chen0Szu-Ying Wu1Yun-Xun Chang2En-Ning Lui3Chih-Kang Chang4Sheng-Wei Lin5Michael Hsiao6Jinn-Moon Yang7Po-Huang Liang8Institute of Biochemical Sciences, National Taiwan UniversityInstitute of Biochemical Sciences, National Taiwan UniversityInstitute of Biochemical Sciences, National Taiwan UniversityInstitute of Biochemical Sciences, National Taiwan UniversityInstitute of Biological Chemistry, Academia SinicaInstitute of Biological Chemistry, Academia SinicaGenomics Research Center, Academia SinicaDepartment of Biological Science and Technology, National Yang Ming Chiao Tung UniversityInstitute of Biochemical Sciences, National Taiwan UniversityAbstract X-linked inhibitor of apoptosis (XIAP) inhibits caspases 3, 7, and 9, thereby preventing cell apoptosis. Endogenous Second mitochondria-derived activator of caspase (Smac) competes out the binding of caspases with XIAP and causes apoptosis, so that Smac mimetics are under clinical trials for anti-cancer chemotherapy. We demonstrated by selectively alkylating caspase 7 (CASP7) to release the active CASP7 for killing the drug-resistant cancer cells with accumulated XIAP:CASP7 resulted from caspase-3 down-regulation (CASP3/DR). However, finding a reversible inhibitor of the protein-protein interaction (PPI) poses a significant challenge. Here, we identified a reversible XIAP:CASP7 inhibitor, 643943, through a multiple-mode virtual screening strategy. In vitro experiments revealed that 643943 bound to CASP7, released the linker-BIR2 domain of XIAP, and activated the caspase. Removing an essential hydroxyl group on 643943 or replacing the OH-interacting Asp93 on CASP7 caused loss of 643943 cytotoxicity, revealing the binding mode. This compound thus selectively killed MCF-7 and other CASP3/DR triple-negative breast cancer cell lines, but not the cancer and normal cell lines expressing higher levels of CASP3 in vitro and in vivo. Moreover, 643943 overcame chemoresistance via down-regulating β-catenin and its associated ABC transporters in paclitaxel-resistant MCF-7 cells. Our studies not only serve as a proof-of-concept for using XIAP:CASP7 as a drug target, but also provide the first reversible XIAP:CASP7 inhibitor for cancer therapy of CASP3/DR malignancies.https://doi.org/10.1038/s41419-025-07774-y
spellingShingle Shih-Hsun Chen
Szu-Ying Wu
Yun-Xun Chang
En-Ning Lui
Chih-Kang Chang
Sheng-Wei Lin
Michael Hsiao
Jinn-Moon Yang
Po-Huang Liang
Blocking XIAP:CASP7-p19 selectively induces apoptosis of CASP3/DR malignancies by a novel reversible small molecule
Cell Death and Disease
title Blocking XIAP:CASP7-p19 selectively induces apoptosis of CASP3/DR malignancies by a novel reversible small molecule
title_full Blocking XIAP:CASP7-p19 selectively induces apoptosis of CASP3/DR malignancies by a novel reversible small molecule
title_fullStr Blocking XIAP:CASP7-p19 selectively induces apoptosis of CASP3/DR malignancies by a novel reversible small molecule
title_full_unstemmed Blocking XIAP:CASP7-p19 selectively induces apoptosis of CASP3/DR malignancies by a novel reversible small molecule
title_short Blocking XIAP:CASP7-p19 selectively induces apoptosis of CASP3/DR malignancies by a novel reversible small molecule
title_sort blocking xiap casp7 p19 selectively induces apoptosis of casp3 dr malignancies by a novel reversible small molecule
url https://doi.org/10.1038/s41419-025-07774-y
work_keys_str_mv AT shihhsunchen blockingxiapcasp7p19selectivelyinducesapoptosisofcasp3drmalignanciesbyanovelreversiblesmallmolecule
AT szuyingwu blockingxiapcasp7p19selectivelyinducesapoptosisofcasp3drmalignanciesbyanovelreversiblesmallmolecule
AT yunxunchang blockingxiapcasp7p19selectivelyinducesapoptosisofcasp3drmalignanciesbyanovelreversiblesmallmolecule
AT enninglui blockingxiapcasp7p19selectivelyinducesapoptosisofcasp3drmalignanciesbyanovelreversiblesmallmolecule
AT chihkangchang blockingxiapcasp7p19selectivelyinducesapoptosisofcasp3drmalignanciesbyanovelreversiblesmallmolecule
AT shengweilin blockingxiapcasp7p19selectivelyinducesapoptosisofcasp3drmalignanciesbyanovelreversiblesmallmolecule
AT michaelhsiao blockingxiapcasp7p19selectivelyinducesapoptosisofcasp3drmalignanciesbyanovelreversiblesmallmolecule
AT jinnmoonyang blockingxiapcasp7p19selectivelyinducesapoptosisofcasp3drmalignanciesbyanovelreversiblesmallmolecule
AT pohuangliang blockingxiapcasp7p19selectivelyinducesapoptosisofcasp3drmalignanciesbyanovelreversiblesmallmolecule