Mitochondrial Complex I Inhibitors Expose a Vulnerability for Selective Killing of Pten-Null Cells

Area of Science:

• Biochemistry
• Oncology
• Molecular Biology

Background:

• Advanced prostate cancer (PC) is characterized by the loss of PTEN and p53 tumor suppressor functions.
• This loss creates a metabolic vulnerability in cancer cells that can be targeted for selective elimination.

Purpose of the Study:

• To identify compounds that selectively kill prostate cancer cells with concomitant loss of PTEN and p53 function.
• To elucidate the mechanism of selective killing and explore therapeutic strategies for advanced PC.

Main Methods:

• Screening of cytotoxic compounds on Pten-null;Trp53-null fibroblasts and Pten-wild-type controls.
• Investigating the role of mitochondrial respiration, specifically complex I (CI) and complex V (CV), in drug sensitivity.
• In vivo studies using a genetically engineered mouse model for metastatic PC.

Main Results:

• Deguelin, a natural compound, selectively killed Pten-null cells by inhibiting mitochondrial CI.
• Pten-null cells showed increased ATP consumption via CV, leading to glucose dependency.
• Lipophilic CI inhibitors demonstrated selective killing of Pten-null cells.
• Deguelin suppressed metastatic PC progression in a mouse model.

Conclusions:

• Loss of PTEN and p53 function confers sensitivity to mitochondrial CI inhibitors in advanced prostate cancer.
• Targeting mitochondrial respiration, particularly CI, represents a promising therapeutic strategy for incurable PC.
• Exploiting the metabolic vulnerability of Pten-null cells offers a pathway for selective cancer therapy.