Connecting endoplasmic reticulum stress to autophagy through IRE1/JNK/beclin-1 in breast cancer cells

Retraction in: /10.3892/ijmm.2021.4997

  • Authors:
    • Xiu Cheng
    • Hao Liu
    • Chen-Chen Jiang
    • Lin Fang
    • Chao Chen
    • Xu-Dong Zhang
    • Zhi-Wen Jiang
  • View Affiliations

  • Published online on: June 25, 2014     https://doi.org/10.3892/ijmm.2014.1822
  • Pages: 772-781
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Abstract

Current experimental results indicate that endoplasmic reticulum (ER) stress activates the unfolded protein response (UPR), which rebuilds ER homeostasis, through which tumor cells can become resistant chemotherapeutic agents. Autophagy is a form of programmed cell death, but it can also play a cytoprotective role in tumor cells, indicating that it has an inverse function. The aim of the present study was to investigate whether tunicamycin (TM) induces autophagy, as well as whether the inhibition of autophagy enhances the apoptosis ofbreast cancer cells induced by TM. In addition, we wished to investigate the mechanisms through which specific UPR targets control autophagy. We found that MCF-7 and MDA-MB‑231 breast cancer cells were insensitive to TM at a relatively low concentration. As shown by western blot analysis, treatment with TM increased the expression of 78 kDa glucose-regulated protein (GRP78), inositol requiring enzyme 1 (IRE1), beclin-1, IRE1α, p-JNK and microtubule-associated protein 1 light chain 3 (LC3); the expression of p62 increased at an early time point during treatment and subsequently decreased. We also used the specific inhibitor of autophagy, 3-methyladenine (3-MA), to elucidate the role of autophagy in ER stress in the breast cancer cells treated with TM. The transformation of LC3-I to LC3-II which was induced by TM, was reversed following treatment with 3-MA. The inhibition of autophagy by 3-MA treatment enhanced the inhibitory and apoptotic rates of TM in the breast cancer cells, as shown by confocal microscopy and flow cytometry. TM increased the misfolded proteins that lead to the activation of ER stress-mediated protection and induced apoptosis paralleled by autophagy in breast cancer cells which was regulated by IRE1/JNK/beclin-1. Autophagy attenuates ER stress by clearing ubiquitinated proteins and decreasing apoptosis, which plays a protective role. The inhibition of autophagy or the promotion of ER stress may be used as therapeutic targets to improve the efficacy of chemotherapeutic drugs.
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September-2014
Volume 34 Issue 3

Print ISSN: 1107-3756
Online ISSN:1791-244X

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Spandidos Publications style
Cheng X, Liu H, Jiang C, Fang L, Chen C, Zhang X and Jiang Z: Connecting endoplasmic reticulum stress to autophagy through IRE1/JNK/beclin-1 in breast cancer cells Retraction in /10.3892/ijmm.2021.4997. Int J Mol Med 34: 772-781, 2014
APA
Cheng, X., Liu, H., Jiang, C., Fang, L., Chen, C., Zhang, X., & Jiang, Z. (2014). Connecting endoplasmic reticulum stress to autophagy through IRE1/JNK/beclin-1 in breast cancer cells Retraction in /10.3892/ijmm.2021.4997. International Journal of Molecular Medicine, 34, 772-781. https://doi.org/10.3892/ijmm.2014.1822
MLA
Cheng, X., Liu, H., Jiang, C., Fang, L., Chen, C., Zhang, X., Jiang, Z."Connecting endoplasmic reticulum stress to autophagy through IRE1/JNK/beclin-1 in breast cancer cells Retraction in /10.3892/ijmm.2021.4997". International Journal of Molecular Medicine 34.3 (2014): 772-781.
Chicago
Cheng, X., Liu, H., Jiang, C., Fang, L., Chen, C., Zhang, X., Jiang, Z."Connecting endoplasmic reticulum stress to autophagy through IRE1/JNK/beclin-1 in breast cancer cells Retraction in /10.3892/ijmm.2021.4997". International Journal of Molecular Medicine 34, no. 3 (2014): 772-781. https://doi.org/10.3892/ijmm.2014.1822