Metformin Induces Resistance of Cancer Cells to the Proteasome Inhibitor Bortezomib.

The anti-diabetic drug metformin is currently tested for the treatment of hematological and solid cancers. Proteasome inhibitors, e.g.

Mitochondrial Regulation of the 26S Proteasome.

The proteasome is the main proteolytic system for targeted protein degradation in the cell and is fine-tuned according to cellular needs. Here, we demonstrate that mitochondrial dysfunction and concomitant metabolic reprogramming of the tricarboxylic acid (TCA) cycle reduce the assembly and activity of the 26S proteasome. Both mitochondrial mutations in respiratory complex I and treatment with the anti-diabetic drug metformin impair 26S proteasome activity.