Autophagy inhibition dysregulates TBK1 signaling and promotes pancreatic inflammation

Shenghong Yang, Yu Imamura, Russell W. Jenkins, Israel Canadas, Shunsuke Kitajima, Amir Aref, Arthur Brannon, Eiji Oki, Adam Castoreno, Zehua Zhu, Tran Thai, Jacob Reibel, Zhirong Qian, Shuji Ogino, Kwok Kwong, Hideo Baba, Alec C. Kimmelman, Marina Pasca Di Magliano, David A. Barbie

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24 Citations (Scopus)

Abstract

Autophagy promotes tumor progression downstreamof oncogenic KRAS, yet also restrains inflammation and dysplasia through mechanisms that remain incompletely characterized. Understanding the basis of this paradox has important implications for the optimal targeting of autophagy in cancer. Using a mouse model of cerulein-induced pancreatitis, we found that loss of autophagy by deletion of Atg5 enhanced activation of the IkB kinase (IKK)-related kinase TBK1 in vivo, associated with increased neutrophil and T-cell infiltration and PD-L1 upregulation. Consistent with this observation, pharmacologic or genetic inhibition of autophagy in pancreatic ductal adenocarcinoma cells, including suppression of the autophagy receptors NDP52 or p62, prolonged TBK1 activation and increased expression of CCL5, IL6, and several other T-cell and neutrophil chemotactic cytokines in vitro. Defective autophagy also promoted PD-L1 upregulation, which is particularly pronounced downstream of IFNg signaling and involves JAK pathway activation. Treatment with the TBK1/IKKe/JAK inhibitor CYT387 (also known as momelotinib) not only inhibits autophagy, but also suppresses this feedback inflammation and reduces PD-L1 expression, limiting KRAS-driven pancreatic dysplasia. These findings could contribute to the dual role of autophagy in oncogenesis and have important consequences for its therapeutic targeting.

Original languageEnglish
Pages (from-to)520-530
Number of pages11
JournalCancer Immunology Research
Volume4
Issue number6
DOIs
Publication statusPublished - Jun 2016

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All Science Journal Classification (ASJC) codes

  • Immunology
  • Cancer Research

Cite this

Yang, S., Imamura, Y., Jenkins, R. W., Canadas, I., Kitajima, S., Aref, A., ... Barbie, D. A. (2016). Autophagy inhibition dysregulates TBK1 signaling and promotes pancreatic inflammation. Cancer Immunology Research, 4(6), 520-530. https://doi.org/10.1158/2326-6066.CIR-15-0235