Bedaquiline, an FDA-approved drug, inhibits mitochondrial ATP production and metastasis in vivo, by targeting the gamma subunit (ATP5F1C) of the ATP synthase

Marco Fiorillo,Federica Sotgia,Antonio Giuseppe Naccarato,Cristian Scatena,Michael P Lisanti

doi:10.1038/s41418-021-00788-x

Abstract

Here, we provide evidence that high ATP production by the mitochondrial ATP-synthase is a new therapeutic target for anticancer therapy, especially for preventing tumor progression. More specifically, we isolated a subpopulation of ATP-high cancer cells which are phenotypically aggressive and demonstrate increases in proliferation, stemness, anchorage-independence, cell migration, invasion and multi-drug resistance, as well as high antioxidant capacity. Clinically, these findings have important implications for understanding treatment failure and cancer cell dormancy. Using bioinformatic analysis of patient samples, we defined a mitochondrial-related gene signature for metastasis, which features the gamma-subunit of the mitochondrial ATP-synthase (ATP5F1C). The relationship between ATP5F1C protein expression and metastasis was indeed confirmed by immunohistochemistry. Next, we used MDA-MB-231 cells as a model system to functionally validate these findings. Importantly, ATP-high MDA-MB-231 cells showed a nearly fivefold increase in metastatic capacity in vivo. Consistent with these observations, ATP-high cells overexpressed (i) components of mitochondrial complexes I–V, including ATP5F1C, and (ii) markers associated with circulating tumor cells (CTCs) and metastasis, such as EpCAM and VCAM1. Knockdown of ATP5F1C expression significantly reduced ATP-production, anchorage-independent growth, and cell migration, as predicted. Similarly, therapeutic administration of the FDA-approved drug, Bedaquiline, downregulated ATP5F1C expression in vitro and prevented spontaneous metastasis in vivo. In contrast, Bedaquiline had no effect on the growth of non-tumorigenic mammary epithelial cells (MCF10A) or primary tumors in vivo. Taken together, our results suggest that mitochondrial ATP depletion is a new therapeutic strategy for metastasis prophylaxis, to avoid treatment failure. In summary, we conclude that mitochondrial ATP5F1C is a promising new biomarker and molecular target for future drug development, for the prevention of metastatic disease progression.

Highlights

ATP is the universal bioenergetic “currency” of all living cells and tissues, including microorganisms, such as prokaryotic bacteria and eukaryotic yeast(s) [1,2,3]In eukaryotes, mitochondrial organelles function as the “powerhouse” of the cell [4,5,6,7]
An inoculum of 1 × 106 MDA-MB-231 cells was added onto the chorioallantoic membrane (CAM) of each egg (E9) and eggs were randomized into groups
Here we demonstrate that high mitochondrial ATP production is a key driver of “stemness” traits and proliferation in cancer cells

Summary

Introduction

ATP is the universal bioenergetic “currency” of all living cells and tissues, including microorganisms, such as prokaryotic bacteria and eukaryotic yeast(s) [1,2,3]In eukaryotes, mitochondrial organelles function as the “powerhouse” of the cell [4,5,6,7]. Mitochondrial dysfunction induces ATP depletion, resulting in autophagy, apoptosis (programmed cell death), and/or necrosis [9]. In MCF7 breast cancer cells, mitochondrial-driven OXPHOS contributes to 80–90% of ATP production, while glycolysis only contributes the remaining 10-20%, under normoxic conditions [14, 15]. Like normal cells, cancer cells are highly dependent on mitochondrial ATP production [14, 16]. It still remains largely unknown if ATP levels in cancer cells contribute to “stemness” and cell cycle progression, as well as their ability to undergo 3D anchorage-independent growth, a characteristic feature of metastatic spread

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