Fig. 2

Mitochondrial stress adaptation and drug resistance. Mitochondrial dynamics are processes related to mitochondrial stress adaptation. These processes maintain proper mitochondrial numbers, structure, and position to ensure their function and could foster cancer drug resistance. (A) Fusion and fission allow mitochondria to constantly form networks or fragments according to cellular metabolic requirements. Mitophagy has been shown to coordinate with fission, facilitating the elimination of excessive or defective mitochondria. (B) While mitochondrial biogenesis and functions are largely regulated by nuclear coding factors, recent advances have revealed that mitochondrial dysfunction activates retrograde (mitochondria-to-nucleus) signaling to modify nuclear gene expression and subsequent cell behavior. This mitochondrial retrograde signaling functions as an adaptive mechanism for tumor cells to sense and mitigate mitochondrial stress. (C) Reshaping, localization, and motility of mitochondria along the microtubules facilitate mitochondria tethering with the ER or other organelles. (D) Recently described nanotunnel formation promotes component exchange and transfer of intercellular mitochondria, which usually increase OXPHOS output and ATP production of recipient cells and confer them with a survival advantage