Comparison of ATG5-/- Bcl-2 tumors expressing p62-GFP versus those expressing EGFP

Autophagy is a starvation response that facilitates cell survival under metabolic stress and yet defects in autophagy promote tumorigenesis. While the role of understarvation is relatively clearer, its mechanistic role in tumorigenesis is poorly understood. We show that defective autophagy promotes protein damage and accumulation of p62, a marker for protein damage accumulation that is cleared through autophagy pathway. The failure to eliminate p62 in autophagy-defective cells, leads to deregulation of cell signalling and gene expression and ultimately promotes tumorigenesis. Thus defective-autophagy is a mechanism for p62 accumulation commonly observed in human tumors.

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Mathew R, Karp CM, Beaudoin B, Vuong N, Chen G, Chen HY, Bray K, Reddy A, Bhanot G, Gelinas C, Dipaola RS, Karantza-Wadsworth V, White E