ATR-101 disrupts mitochondrial functions in adrenocortical carcinoma cells and in vivo

Area of Science:

• Oncology
• Pharmacology
• Biochemistry

Background:

• Adrenocortical carcinoma (ACC) presents a significant clinical challenge with limited effective treatment options for advanced or metastatic disease.
• Understanding the mechanisms of novel therapeutic agents is crucial for developing improved ACC treatments.

Purpose of the Study:

• To elucidate the mechanisms underlying the cytotoxic, xenograft suppressive, and adrenalytic effects of ATR-101, a potential ACC therapeutic.
• To investigate ATR-101's impact on cellular energy metabolism and mitochondrial function in ACC models.

Main Methods:

• In vitro and in vivo studies using ACC cell lines (H295R) and xenografts in mice.
• Assessment of apoptosis, mitochondrial function (hyperpolarization, ATP depletion, reactive oxygen species), and F1F0-ATPase activity.
• In vivo administration in guinea pigs to evaluate adrenalytic effects and lipofuscin accumulation.

Main Results:

• ATR-101 inhibited ACC xenograft growth and induced apoptosis in cancer cells.
• The agent triggered mitochondrial hyperpolarization, reactive oxygen release, and ATP depletion, preceding caspase activation.
• ATR-101 directly inhibited F1F0-ATPase, suppressing mitochondrial ATP synthesis and causing adrenalytic effects in vivo.

Conclusions:

• ATR-101 demonstrates significant anti-cancer activity against ACC through a mechanism involving mitochondrial dysfunction and energy depletion.
• The findings support ATR-101's development as a novel therapeutic agent for adrenocortical carcinoma.
• Adrenalytic compounds like ATR-101 represent a promising class of drugs for treating ACC.