Ghost mitochondria drive metastasis through adaptive GCN2/Akt therapeutic vulnerability

Area of Science:

• Mitochondrial biology
• Cancer research
• Cellular metabolism

Background:

• Mitochondrial dysfunction is a hallmark of cancer, yet its regulatory mechanisms remain unclear.
• Mic60 (Mitofilin) is crucial for mitochondrial structure and function.
• Tumor cells often exhibit altered mitochondrial properties.

Purpose of the Study:

• To investigate the role of Mic60 in cancer metabolism and progression.
• To understand how mitochondrial damage influences tumor behavior, including metastasis.
• To identify potential therapeutic targets in Mic60-low tumors.

Main Methods:

• Analysis of Mic60 levels in human tumors.
• Assessment of mitochondrial integrity and bioenergetics upon Mic60 depletion.
• Investigation of gene expression changes, including innate immunity and EMT.
• Small-molecule drug screening to identify vulnerabilities in Mic60-low cancer cells.

Main Results:

• Human tumors frequently display heterogeneous and reduced Mic60 levels.
• Mic60 depletion leads to mitochondrial collapse but promotes cancer cell survival and proliferation.
• Loss of Mic60 triggers innate immunity signaling, EMT, and enhanced cell motility.
• Compensatory activation of GCN2 and Akt signaling sustains Mic60-low tumor viability.
• Damaged mitochondria in Mic60-low tumors drive metastatic dissemination.

Conclusions:

• Acutely damaged mitochondria, driven by Mic60 loss, promote tumor progression and metastasis.
• Mic60 depletion creates a therapeutic vulnerability exploitable through targeting stress response pathways.
• Targeting Mic60 or related pathways offers a novel strategy for treating metastasis-prone cancers.