NOTCH-induced aldehyde dehydrogenase 1A1 deacetylation promotes breast cancer stem cells
Di Zhao, … , Kun-Liang Guan, Qun-Ying Lei
Di Zhao, … , Kun-Liang Guan, Qun-Ying Lei
Published November 10, 2014
Citation Information: J Clin Invest. 2014;124(12):5453-5465. https://doi.org/10.1172/JCI76611.
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Research Article Oncology

NOTCH-induced aldehyde dehydrogenase 1A1 deacetylation promotes breast cancer stem cells

Abstract

High aldehyde dehydrogenase (ALDH) activity is a marker commonly used to isolate stem cells, particularly breast cancer stem cells (CSCs). Here, we determined that ALDH1A1 activity is inhibited by acetylation of lysine 353 (K353) and that acetyltransferase P300/CBP–associated factor (PCAF) and deacetylase sirtuin 2 (SIRT2) are responsible for regulating the acetylation state of ALDH1A1 K353. Evaluation of breast carcinoma tissues from patients revealed that cells with high ALDH1 activity have low ALDH1A1 acetylation and are capable of self-renewal. Acetylation of ALDH1A1 inhibited both the stem cell population and self-renewal properties in breast cancer. Moreover, NOTCH signaling activated ALDH1A1 through the induction of SIRT2, leading to ALDH1A1 deacetylation and enzymatic activation to promote breast CSCs. In breast cancer xenograft models, replacement of endogenous ALDH1A1 with an acetylation mimetic mutant inhibited tumorigenesis and tumor growth. Together, the results from our study reveal a function and mechanism of ALDH1A1 acetylation in regulating breast CSCs.

Authors

Di Zhao, Yan Mo, Meng-Tian Li, Shao-Wu Zou, Zhou-Li Cheng, Yi-Ping Sun, Yue Xiong, Kun-Liang Guan, Qun-Ying Lei

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Figure 2

SIRT2 deacetylates and activates ALDH1A1.

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SIRT2 deacetylates and activates ALDH1A1. (A) SIRT2, not SIRT1, decrease...
(A) SIRT2, not SIRT1, decreased K353 acetylation and increased ALDH1A1 activity. 293T cells were transfected with the indicated plasmids. FLAG-ALDH1A1 was immunoprecipitated, and ALDH1A1 activity was assayed. (B) SIRT2 deacetylase activity was required to increase ALDH1A1 activity. 293T cells were cotransfected with FLAG-ALDH1A1 and SIRT2 WT or the inactive mutant H187Y. (C) SIRT2 knockdown increased K353 acetylation and decreased ALDH1A1 activity. 293T cells were transfected with the indicated plasmids and SIRT2 siRNA oligonucleotides. ALDH1A1 was immunoprecipitated and activity was assayed. ALDH1A1 acetylation at K353 was determined by Western blotting. (A–C) ALDH1A1 activity was normalized to protein levels, and relative enzyme activity data represent the mean ± SD of triplicate experiments. (D) SIRT2 overexpression decreased endogenous ALDH1A1 K353 acetylation. Plasmid expressing SIRT2 WT or the inactive mutant H187Y was transfected into HEPG2 cells, and endogenous K353 acetylation and ALDH1A1 were determined. (E) SIRT2 knockdown increased endogenous ALDH1A1 K353 acetylation. siRNA oligonucleotide targeting SIRT2 was transfected into HEPG2 cells, and the levels of endogenous K353 acetylation, ALDH1A1, and SIRT2 protein were determined by Western blotting. (F and G) ALDH1A1 bound to SIRT2. (F) The indicated plasmids were cotransfected into 293T cells, and ALDH1A1-SIRT2 binding was determined by IP and Western blotting. (G) Interaction of endogenous ALDH1A1 and SIRT2 in HEPG2 cells was determined by IP and Western blotting.