Abstract 1332: Autophagic clearance of protein aggregates is impaired in cancer cells with dysfunctional mitochondria

Abstract Mitophagy and aggrephagy are selective types of autophagy that degrade damaged mitochondria and protein aggregates, respectively. Dysfunctional mitochondria are known to undergo mitophagy and cause protein aggregation. How a cell can simultaneously coordinate the removal of dysfunctional mitochondria and protein aggregates via autophagy is unknown. Here, two agents, Mitoquinone (MitoQ) and MitoApocynin (MitoApo), known to induce mitochondrial dysfunction and mitophagy in MDA-MB-231 cells were used to investigate the accumulation of protein aggregates and the mechanisms that contribute to selective autophagy. Using a protein aggregate dye and a poly-ubiquitinated antibody, carbonyl cyanide m-chlorophenyl hydrazine (CCCP), MitoQ, and MitoApo were identified as agents that caused an accumulation of poly-ubiquitinated protein aggregates in cancer cells by FACS analysis and confocal imaging. Microflow imaging of the cellular lysates confirmed a relative accumulation of large protein (>460 kDa) complexes. To establish the presence of aggrephagy, the aggregates were colocalized with LC3. Wild type and ATG7 knockout MEF cells were used to test whether protein aggregates accumulated in an autophagy-dependent manner. Our data currently demonstrates the kinetics of autophagic clearance of drug-induced protein aggregation and dysfunctional mitochondria. Citation Format: Thomas Biel, Ashutosh Rao. Autophagic clearance of protein aggregates is impaired in cancer cells with dysfunctional mitochondria [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1332.