Salinomycin Triggers Human Colorectal Cancer HCT116 Cell Death by Targeting Unfolded Protein Responses and Autophagy Pathways

Document Type : Research/Original Article


1 Autophagy Research Center, Shiraz University of Medical Sciences, Shiraz, Iran

2 Department of Biochemistry, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran

3 Endocrinology and Metabolism Research Center, Shiraz University of Medical Sciences, Shiraz, Iran

4 Autophagy Research Center, Department of Biochemistry, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran


Background: Autophagy and the unfolded protein response (UPR) are important pathways in colorectal tumorigenesis and drug resistance, rendering them as potential therapeutic targets for treating this cancer. As an ionophoric polyether antibiotic, salinomycin has anti-cancer effects and overcomes drug resistance in cancer cells. Considering the minimal information on the molecular action mechanism of salinomycin in colorectal cancer (CRC), this study was designed to investigate the effect of this compound on autophagy and UPR pathways in CRC cells. 
Methods: The in vitro cytotoxicity of salinomycin on CRC cell line HCT116 was determined using the MTT assay by treating the cells with different concentrations of salinomycin for 24 and 48 h. The gene expression analysis of three main autophagy biomarkers (Beclin1, LC3, and P62) and two UPR biomarkers (XBP-1s and CHOP) was performed using quantitative real-time polymerase chain reaction (RT-PCR). Data were analyzed with GraphPad Prism 8 software. 
Results: Salinomycin had cytotoxic effects on HCT116 cells in a time- and dose-dependent manner. The expression analysis of the UPR and autophagy-related genes showed UPR activation at both 24 h and 48 h (increase of XBP-1s and CHOP), autophagy activation at 24 h (increase of Beclin 1, LC3II, and decrease of P62), and autophagy flux inhibition at 48 h (increase of Beclin 1, LC3II and P62). 
Conclusion: The anti-cancer activity of salinomycin against the HCT116 cell line seems to be through triggering cell death by targeting UPR and autophagy pathways. Further studies are required to confirm our results.


  1. Rawla P, Sunkara T, Barsouk A. Epidemiology of colorectal cancer: incidence, mortality, survival, and risk factors. Gastroenterology Review/Przegląd Gastroenterologiczny. 2019;14(2):89-103.
  2. Mokarram P, Albokashy M, Zarghooni M, Moosavi MA, Sepehri Z, Chen QM, et al. New frontiers in the treatment of colorectal cancer: Autophagy and the unfolded protein response as promising targets. Autophagy. 2017;13(5):781-819.
  3. Huang J, Pan H, Wang J, Wang T, Huo X, Ma Y, et al. Unfolded protein response in colorectal cancer. Cell & bioscience. 2021;11(1):1-16.
  4. Corazzari M, Gagliardi M, Fimia GM, Piacentini M. Endoplasmic reticulum stress, unfolded protein response, and cancer cell fate. Frontiers in oncology. 2017;7:78.
  5. Siri M, Behrouj H, Dastghaib S, Zamani M, Likus W, Rezaie S, et al. Casein Kinase-1-alpha inhibitor (D4476) sensitizes microsatellite instable colorectal cancer cells to 5-fluorouracil via authophagy flux inhibition. Archivum Immunologiae et Therapiae Experimentalis. 2021;69:1-16.
  6. Paskeh MDA, Entezari M, Clark C, Zabolian A, Ranjbar E, Farahani MV, et al. Targeted regulation of autophagy using nanoparticles: new insight into cancer therapy. Biochimica et Biophysica Acta (BBA)-Molecular Basis of Disease. 2022;1868(3):166326.
  7. Dastghaib S, Hajiahmadi S, Seyfoori A, Amereh M, Zamani M, Shahsavari Z, et al. Role of apoptosis, autophagy, and the unfolded protein response in glioblastoma chemoresistance. Glioblastoma Resistance to Chemotherapy: Molecular Mechanisms and Innovative Reversal Strategies: Elsevier; 2021. p. 201-42.
  8. Russell RC, Guan KL. The multifaceted role of autophagy in cancer. The EMBO Journal. 2022;41(13):e110031.
  9. Siwecka N, Rozpędek W, Pytel D, Wawrzynkiewicz A, Dziki A, Dziki Ł, et al. Dual role of endoplasmic reticulum stress-mediated unfolded protein response signaling pathway in carcinogenesis. International journal of molecular sciences. 2019;20(18):4354.
  10. Jiang J, Li H, Qaed E, Zhang J, Song Y, Wu R, et al. Salinomycin, as an autophagy modulator--a new avenue to anticancer: a review. Journal of Experimental & Clinical Cancer Research. 2018;37(1):1-13.
  11. Gupta PB, Onder TT, Jiang G, Tao K, Kuperwasser C, Weinberg RA, et al. Identification of selective inhibitors of cancer stem cells by high-throughput screening. Cell. 2009;138(4):645-59.
  12. Xipell E, Gonzalez-Huarriz M, de Irujo JJM, García-Garzón A, Lang FF, Jiang H, et al. Salinomycin induced ROS results in abortive autophagy and leads to regulated necrosis in glioblastoma. Oncotarget. 2016;7(21):30626.
  13. Hwang K-E, Kim H-J, Song I-S, Park C, Jung JW, Park D-S, et al. Salinomycin suppresses TGF-β1-induced EMT by down-regulating MMP-2 and MMP-9 via the AMPK/SIRT1 pathway in non-small cell lung cancer. International Journal of Medical Sciences. 2021;18(3):715.
  14. Liu Q, Sun J, Luo Q, Ju Y, Song G. Salinomycin suppresses tumorigenicity of liver cancer stem cells and Wnt/beta-catenin signaling. Current stem cell research & therapy. 2021;16(5):630-7.
  15. Dewangan J, Srivastava S, Mishra S, Divakar A, Kumar S, Rath SK. Salinomycin inhibits breast cancer progression via targeting HIF-1α/VEGF mediated tumor angiogenesis in vitro and in vivo. Biochemical Pharmacology. 2019;164:326-35.
  16. Yu J, Yang Y, Li S, Meng P. Salinomycin triggers prostate cancer cell apoptosis by inducing oxidative and endoplasmic reticulum stress via suppressing Nrf2 signaling. Experimental and Therapeutic Medicine. 2021;22(3):1-9.
  17. Klose J, Trefz S, Wagner T, Steffen L, Preißendörfer Charrier A, Radhakrishnan P, et al. Salinomycin: Anti-tumor activity in a pre-clinical colorectal cancer model. PLoS One. 2019;14(2):e0211916.
  18. Michalak M, Lach MS, Antoszczak M, Huczyński A, Suchorska WM. Overcoming resistance to platinum-based drugs in ovarian cancer by salinomycin and its derivatives—an in vitro study. Molecules. 2020;25(3):537.
  19. Carroll SL, Longo JF. Salinomycin targets the genome of radioresistant cells in glioblastomas. Oxford University Press US; 2020. p. 167-8.
  20. Zhou Y, Liang C, Xue F, Chen W, Zhi X, Feng X, et al. Salinomycin decreases doxorubicin resistance in hepatocellular carcinoma cells by inhibiting the β-catenin/TCF complex association via FOXO3a activation. Oncotarget. 2015;6(12):10350.
  21. Daman Z, Montazeri H, Azizi M, Rezaie F, Ostad SN, Amini M, et al. Polymeric micelles of PEG-PLA copolymer as a carrier for salinomycin against gemcitabine-resistant pancreatic cancer. Pharmaceutical research. 2015;32:3756-67.
  22. Yue W, Hamaï A, Tonelli G, Bauvy C, Nicolas V, Tharinger H, et al. Inhibition of the autophagic flux by salinomycin in breast cancer stem-like/progenitor cells interferes with their maintenance. Autophagy. 2013;9(5):714-29.
  23. Verdoodt B, Vogt M, Schmitz I, Liffers S-T, Tannapfel A, Mirmohammadsadegh A. Salinomycin induces autophagy in colon and breast cancer cells with concomitant generation of reactive oxygen species. 2012.
  24. Liu Y, Hao Y, Li Y, Zheng Y, Dai J, Zhong F, et al. Salinomycin induces autophagic cell death in salinomycin-sensitive melanoma cells through inhibition of autophagic flux. Scientific Reports. 2020;10(1):1-14.
  25. Yu S-N, Kim S-H, Kim K-Y, Ji J-H, Seo Y-K, Yu HS, et al. Salinomycin induces endoplasmic reticulum stress‑mediated autophagy and apoptosis through generation of reactive oxygen species in human glioma U87MG cells. Oncology reports. 2017;37(6):3321-8.
  26. Li T, Su L, Zhong N, Hao X, Zhong D, Singhal S, et al. Salinomycin induces cell death with autophagy through activation of endoplasmic reticulum stress in human cancer cells. Autophagy. 2013;9(7):1057-68.
  27. Yuan H, Li Y, Zou Y, Cai C, Shi X, Su Y. Salinomycin suppresses T24 cells by regulating KDM1A and the unfolded protein response pathway. Cytotechnology. 2022;74(5):579-90.
  28. Huang X, Borgström Br, Stegmayr J, Abassi Y, Kruszyk M, Leffler H, et al. The molecular basis for inhibition of stemlike cancer cells by salinomycin. ACS Central Science. 2018;4(6):760-7.
  29. Ghavami S, Mutawe MM, Sharma P, Yeganeh B, McNeill KD, Klonisch T, et al. Mevalonate cascade regulation of airway mesenchymal cell autophagy and apoptosis: a dual role for p53. PloS one. 2011;6(1):e16523.
  30. Yun CW, Jeon J, Go G, Lee JH, Lee SH. The dual role of autophagy in cancer development and a therapeutic strategy for cancer by targeting autophagy. International Journal of Molecular Sciences. 2020;22(1):179.
  31. Mowers EE, Sharifi MN, Macleod KF. Autophagy in cancer metastasis. Oncogene. 2017;36(12):1619-30.
  32. Papaioannou A, Chevet E. Driving cancer tumorigenesis and metastasis through UPR signaling. Coordinating Organismal Physiology Through the Unfolded Protein Response. 2018:159-92.