Validation of a Strategy for Cancer Therapy: Delivering Aminoglycoside Drugs to Mitochondria in HeLa Cells

Mitochondria in human cancer cells have been implicated in cancer cell proliferation, invasion, metastasis, and even drug-resistance mechanisms, making them a potential target organelle for the treatment of human malignancies. Gentamicin (GM), an aminoglycoside drug (AG), is a small molecule that functions as an antibiotic and has ototoxic and nephrotoxic characteristics. Thus, the delivery of GM to mitochondria in cancer cells would be an innovative anticancer therapeutic strategy. In this study, we attempted mitochondrial delivery of GM in HeLa cells derived from a human cervical cancer. For the mitochondrial delivery, we used MITO-Porter, a liposomal nanocarrier for mitochondrial delivery via membrane fusion. We first encapsulated GM in the aqueous phase of the carrier to construct GM-MITO-Porter. Flow cytometry analysis and fluorescent microscopy observations permitted us to confirm that the GM-MITO-Porter was efficiently taken up by HeLa cells and accumulated in mitochondria, whereas naked GM was not taken up by the cells. Moreover, cell viability assays using HeLa cells showed that the GM-MITO-Porter induced strong cytotoxic effects related to mitochondrial disorder. This finding is the first report of the mitochondrial delivery of an AG to cancer cells for cancer therapeutic strategy.