TY - JOUR
T1 - HuR posttranscriptionally regulates WEE1
T2 - Implications for the DNA damage response in pancreatic cancer cells
AU - Lal, Shruti
AU - Burkhart, Richard A.
AU - Beeharry, Neil
AU - Bhattacharjee, Vikram
AU - Londin, Eric R.
AU - Cozzitorto, Joseph A.
AU - Romeo, Carmella
AU - Jimbo, Masaya
AU - Norris, Zoë A.
AU - Yeo, Charles J.
AU - Sawicki, Janet A.
AU - Winter, Jordan M.
AU - Rigoutsos, Isidore
AU - Yen, Timothy J.
AU - Brody, Jonathan R.
PY - 2014/2/15
Y1 - 2014/2/15
N2 - HuR (ELAV1), an RNA-binding protein abundant in cancer cells, primarily resides in the nucleus, but under specific stress (e.g., gemcitabine), HuR translocates to the cytoplasm in which it tightly modulates the expression of mRNA survival cargo. Here, we demonstrate for the first time that stressing pancreatic ductal adenocarcinoma (PDA) cells by treatment with DNA-damaging anticancer agents (mitomycin C, oxaliplatin, cisplatin, carboplatin, and a PARP inhibitor) results in HuR's translocation from the nucleus to the cytoplasm. Importantly, silencing HuR in PDA cells sensitized the cells to these agents, whereas overexpressing HuR caused resistance. HuR's role in the efficacy of DNA-damaging agents in PDA cells was, in part, attributed to the acute upregulation of WEE1 by HuR. WEE1, a mitotic inhibitor kinase, regulates the DNA damage repair pathway, and therapeutic inhibition of WEE1 in combination with chemotherapy is currently in early phase trials for the treatment of cancer.Wevalidate WEE1 as a HuR target in vitro and in vivo by demonstrating (i) direct binding of HuR to WEE10s mRNA (a discrete 56-bp region residing in the 30 untranslated region) and (ii) HuR siRNA silencing and overexpression directly affects the protein levels of WEE1, especially after DNA damage. HuR's positive regulation of WEE1 increases γ-H2AX levels, induces Cdk1 phosphorylation, and promotes cell-cycle arrest at the G2-M transition. We describe a novel mechanism that PDA cells use to protect against DNA damage in which HuR posttranscriptionally regulates the expression and downstream function of WEE1 upon exposure to DNA-damaging agents.
AB - HuR (ELAV1), an RNA-binding protein abundant in cancer cells, primarily resides in the nucleus, but under specific stress (e.g., gemcitabine), HuR translocates to the cytoplasm in which it tightly modulates the expression of mRNA survival cargo. Here, we demonstrate for the first time that stressing pancreatic ductal adenocarcinoma (PDA) cells by treatment with DNA-damaging anticancer agents (mitomycin C, oxaliplatin, cisplatin, carboplatin, and a PARP inhibitor) results in HuR's translocation from the nucleus to the cytoplasm. Importantly, silencing HuR in PDA cells sensitized the cells to these agents, whereas overexpressing HuR caused resistance. HuR's role in the efficacy of DNA-damaging agents in PDA cells was, in part, attributed to the acute upregulation of WEE1 by HuR. WEE1, a mitotic inhibitor kinase, regulates the DNA damage repair pathway, and therapeutic inhibition of WEE1 in combination with chemotherapy is currently in early phase trials for the treatment of cancer.Wevalidate WEE1 as a HuR target in vitro and in vivo by demonstrating (i) direct binding of HuR to WEE10s mRNA (a discrete 56-bp region residing in the 30 untranslated region) and (ii) HuR siRNA silencing and overexpression directly affects the protein levels of WEE1, especially after DNA damage. HuR's positive regulation of WEE1 increases γ-H2AX levels, induces Cdk1 phosphorylation, and promotes cell-cycle arrest at the G2-M transition. We describe a novel mechanism that PDA cells use to protect against DNA damage in which HuR posttranscriptionally regulates the expression and downstream function of WEE1 upon exposure to DNA-damaging agents.
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UR - http://www.scopus.com/inward/citedby.url?scp=84894256396&partnerID=8YFLogxK
U2 - 10.1158/0008-5472.CAN-13-1915
DO - 10.1158/0008-5472.CAN-13-1915
M3 - Article
C2 - 24536047
AN - SCOPUS:84894256396
SN - 0008-5472
VL - 74
SP - 1128
EP - 1140
JO - Cancer Research
JF - Cancer Research
IS - 4
ER -