p53-independent Noxa induction by cisplatin is regulated by ATF3/ATF4 in head and neck squamous cell carcinoma cells.

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p53-independent Noxa induction by cisplatin is regulated by ATF3/ATF4 in head and neck squamous cell carcinoma cells.

Mol Oncol. 2018 Jan 19;:

Authors: Sharma K, Vu TT, Cook W, Naseri M, Zhan K, Nakajima W, Harada H

Abstract
The platinum-based DNA damaging agent cisplatin is used as a standard therapy for locally advanced head and neck squamous cell carcinoma (HNSCC). However, the mechanisms underpinning the cytotoxic effects of this compound are not entirely elucidated. Cisplatin produces anticancer effects primarily via activation of the DNA damage response, followed by inducing BCL-2 family-dependent mitochondrial apoptosis. We have previously demonstrated that cisplatin induces the expression of pro-apoptotic BCL-2 family protein, Noxa, that can bind to the pro-survival BCL-2 family protein, MCL-1, to inactivate its function and induce cell death. Here, we show that the up-regulation of Noxa is critical for cisplatin-induced apoptosis in p53-null HNSCC cells. This induction is regulated at the transcriptional level. With a series of Noxa promoter-luciferase reporter assays, we find that the CRE (cAMP response element) in the promoter is critical for the Noxa induction by cisplatin treatment. Among the CREB/ATF transcription factors, ATF3 and ATF4 are induced by cisplatin, and down-regulation of ATF3 or ATF4 reduced cisplatin-induced Noxa. ATF3 and ATF4 bind to and cooperatively activate the Noxa promoter. Furthermore, ERK1 is involved in cisplatin-induced ATF4 and Noxa induction. In conclusion, ATF3 and ATF4 are important regulators that induce Noxa by cisplatin treatment in a p53-independent manner.

PMID: 29352505 [PubMed - as supplied by publisher]

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