Downregulation of E2F1 during ER stress is required to induce apoptosis
Abstract
The endoplasmic reticulum (ER) has recently emerged as an alternative target to induce cell death in tumours, because prolonged ER stress results in the induction of apoptosis even in chemoresistant transformed cells. Here, we show that the DNA-damage-responsive pro-apoptotic factor E2F1 is unexpectedly downregulated during the ER stress-mediated apoptotic programme. E2F1 decline is a late event during the ER response and is mediated by the two unfolded protein response (UPR) sensors ATF6 and IRE1 (also known as ERN1). Whereas ATF6 directly interacts with the E2F1 promoter, IRE1 requires the involvement of the known E2F1 modulator E2F7, through the activation of its main target Xbp-1. Importantly, inhibition of the E2F1 decrease prevents ER-stress-induced apoptosis, whereas E2F1 knockdown efficiently sensitises cells to ER stress-dependent apoptosis, leading to the upregulation of two main factors in the UPR pro-apoptotic execution phase, Puma and Noxa (also known as BBC3 and PMAIP1, respectively). Our results point to a novel key role of E2F1 in the cell survival/death decision under ER stress, and unveil E2F1 inactivation as a valuable novel potential therapeutic strategy to increase the response of tumour cells to ER stress-based anticancer treatments.
Autore Pugliese
Tutti gli autori
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Pagliarini V. , Giglio P. , Bernardoni P. , De Zio D. , Fimia G.M. , Piacentini M. , Corazzari M.
Titolo volume/Rivista
JOURNAL OF CELL SCIENCE
Anno di pubblicazione
2015
ISSN
0021-9533
ISBN
Non Disponibile
Numero di citazioni Wos
10
Ultimo Aggiornamento Citazioni
25/04/2018
Numero di citazioni Scopus
10
Ultimo Aggiornamento Citazioni
26/04/2018
Settori ERC
Non Disponibile
Codici ASJC
Non Disponibile
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