Abstract
The integrated stress response (ISR) converges on eIF2α phosphorylation to regulate protein synthesis. ISR is activated by several stress conditions, including endoplasmic reticulum (ER) stress, executed by protein kinase R-like endoplasmic reticulum kinase (PERK). We report that ER stress combined with ISR inhibition causes an impaired maturation of several tyrosine kinase receptors (RTKs), consistent with a partial block of their trafficking from the ER to the Golgi. Other proteins mature or are secreted normally, indicating selective retention in the ER (sERr). sERr is relieved upon protein synthesis attenuation and is accompanied by the generation of large mixed disulfide bonded complexes, including ERp44. sERr was pharmacologically recapitulated by combining the HIV-protease inhibitor nelfinavir with ISRIB, an experimental drug that inhibits ISR. Nelfinavir/ISRIB combination is highly effective to inhibit the growth of RTK-addicted cell lines and hepatocellular (HCC) cells in vitro and in vivo. Thus, pharmacological sERr can be utilized as a modality for cancer treatment.
Original language | English |
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Article number | 1304 |
Journal | Nature Communications |
Volume | 11 |
Issue number | 1 |
DOIs | |
State | Published - 1 Dec 2020 |
Bibliographical note
Funding Information:B.T. is the incumbent of the David Eisenberg Chair in Pharmacy. Research was funded by grants from the David R. Bloom Center for Pharmacy, the Dr. Adolph and Klara Brettler Center for Research in Pharmacology, Israel Cancer Association Grant No. 20200018 (B.T.), ISF Grants Nos. 696/2014 (B.T.), 1537/18, 1765/13 (D.R.), Treatment H2020-MSCA-ITN-721236 (B.T. and P.D.), START Program of the Medical Faculty of the RWTH Aachen University (T.W., 691517), German Israeli Fund (Grant no. I-1471-414.13/2018) to B.T. and M.H. M.M. is the recipient of the Zvi Yanai Doctoral Fellowship of the Israeli Ministry of Science and Technology.
Publisher Copyright:
© 2020, The Author(s).