Simultaneous induction and blockade of autophagy by a single agent

• Published in: Cell death & disease 2018-03, Vol.9 (3), p.353-15, Article 353
• Main Authors: Kucharewicz, Karolina, Dudkowska, Magdalena, Zawadzka, Anna, Ogrodnik, Mikolaj, Szczepankiewicz, Andrzej A., Czarnocki, Zbigniew, Sikora, Ewa
• Format: Article
• Language: English
• Subjects: 13/109; 13/21; 13/31; 14/1; 14/19; 14/28; 14/34; 14/35; 14/63; 82/29; AKT protein; Antibodies; Antineoplastic Agents - chemistry; Antineoplastic Agents - pharmacology; Apoptosis; Autophagy; Autophagy - drug effects; Biochemistry; Biomedical and Life Sciences; Breast cancer; Cancer; Cell Biology; Cell Culture; Cell death; Cell Death - drug effects; Cell Proliferation - drug effects; Cell Survival - drug effects; Cellular Senescence - drug effects; Cholinesterase Inhibitors - chemistry; Cholinesterase Inhibitors - pharmacology; Electron microscopy; Fibroblasts; G1 Phase - drug effects; HCT116 Cells; Humans; Immunology; LAMP-1 protein; Life Sciences; MCF-7 Cells; Melatonin; Melatonin - analogs & derivatives; Melatonin - pharmacology; Phagocytosis; Senescence; Tacrine; Tacrine - analogs & derivatives; Tacrine - pharmacology; TOR protein
• ISSN: 2041-4889; 2041-4889
• DOI: 10.1038/s41419-018-0383-6

Besides cell death, autophagy and cell senescence are the main outcomes of anticancer treatment. We demonstrate that tacrine-melatonin heterodimer C10, a potent anti-Alzheimer’s disease drug, has an antiproliferative effect on MCF-7 breast cancer cells. The main cell response to a 24 h-treatment with C10 was autophagy enhancement accompanied by inhibition of mTOR and AKT pathways. Significantly increased autophagy markers, such as LC3B- and ATG16L-positive vesicles, confirmed autophagy induction by C10. However, analysis of autophagic flux using mCherry-GFP-LC3B construct revealed inhibition of autophagy by C10 at the late-stage. Moreover, electron microscopy and analysis of colocalization of LC3B and LAMP-1 proteins provided evidence of autophagosome-lysosome fusion with concomitant inhibition of autolysosomal degradation function. After transient treatment with IC 50 dose of C10 followed by cell culture without the drug, 20% of MCF-7 cells displayed markers of senescence. On the other hand, permanent cell treatment with C10 resulted in massive cell death on the 5th or 6th day. Recently, an approach whereby autophagy is induced by one compound and simultaneously blocked by the use of another one has been proposed as a novel anticancer strategy. We demonstrate that the same effect may be achieved using a single agent, C10. Our findings offer a new, promising strategy for anticancer treatment.