Author/Editor     Avsec, Damjan; Jakoš Djordjevič, Alma Tana; Kandušer, Maša; Podgornik, Helena; Škerget, Matevž; Mlinarič-Raščan, Irena
Title     Targeting autophagy triggers apoptosis and complements the action of venetoclax in chronic lymphocytic leukemia cells
Type     članek
Vol. and No.     Letnik 13, št. 18
Publication year     2021
Volume     str. 1-20
ISSN     2072-6694 - Cancers
Language     eng
Abstract     Continuous treatment of patients with chronic lymphocytic leukemia (CLL) with venetoclax, an antagonist of the anti-apoptotic protein Bcl-2, can result in resistance, which highlights the need for novel targets to trigger cell death in CLL. Venetoclax also induces autophagy by perturbing the Bcl-2/Beclin-1 complex, so autophagy might represent a target in CLL. Diverse autophagy inhibitors were assessed for cytotoxic activities against patient-derived CLL cells. The AMPK inhibitor dorsomorphin, the ULK1/2 inhibitor MRT68921, and the autophagosome-lysosome fusion inhibitor chloroquine demonstrated concentration-dependent and time-dependent cytotoxicity against CLL cells, even in those from hard-to-treat patients who carried del(11q) and del(17p). Dorsomorphin and MRT68921 but not chloroquine triggered caspase-dependent cell death. According to the metabolic activities of CLL cells and PBMCs following treatments with 10 [micro]M dorsomorphin (13% vs. 84%), 10 [micro]M MRT68921 (7% vs. 78%), and 25 [micro]M chloroquine (41% vs. 107%), these autophagy inhibitors are selective toward CLL cells. In these CLL cells, venetoclax induced autophagy, and addition of dorsomorphin, MRT68921, or chloroquine showed potent synergistic cytotoxicities. Additionally, MRT68921 alone induced G2 arrest, but when combined with venetoclax, it triggered caspase-dependent cytotoxicity. These data provide the rationale to target autophagy and for autophagy inhibitors as potential treatments for patients with CLL.
Descriptors     Kronična limfocitna levkemija
Tarčno zdravljenje
Apoptoza
Keywords     avtofagi
odpornost na zdravila
tarčna terapija
chronic lymphocytic leukemia
autophagy
AMPK/ULK1
venetoclax
drug resistance
targeted therapy