Antimalarial Drug Atovaquone Shows Promise Against Triple-Negative Breast Cancer

Triple-negative breast cancer represents one of the most aggressive forms of breast cancer, with limited treatment options and poor patient outcomes. While most cases overexpress EGFR receptors, making them theoretical targets for EGFR inhibitor drugs, these treatments often fail due to cancer cell resistance mechanisms.

Researchers investigated why EGFR inhibitors show poor effectiveness in triple-negative breast cancer. They discovered that a protein called TDP43 plays a crucial role in drug resistance by relocating from the cell nucleus to mitochondria when cancer cells are exposed to EGFR inhibitors.

The study revealed that TDP43 enhances cellular energy production through oxidative phosphorylation, which fuels cancer stem cells and promotes treatment resistance. When researchers knocked down TDP43 expression or used atovaquone to inhibit it, cancer cells became significantly more sensitive to EGFR inhibitors.

Atovaquone, currently approved as an antimalarial medication, emerged as an effective TDP43 inhibitor that disrupts cancer cell energy metabolism. The combination of atovaquone with EGFR inhibitors showed enhanced anti-cancer effects compared to either treatment alone.

This research has significant implications for cancer treatment, as it identifies a potential drug repurposing opportunity using an already-approved medication. The findings suggest that targeting cellular energy metabolism alongside growth factor receptors could overcome treatment resistance in aggressive cancers, potentially improving survival outcomes for patients with limited therapeutic options.