Updated project metadata. Cancer cells are known to reprogram their metabolism to adapt to adverse conditions dictated by tumor growth and microenvirontment. A subtype of cancer cells with stem-like properties, known as cancer stem cells (CSC) is thought to be responsible for tumour recurrence. These consequences are fatal for cancer patients as metastatic tumors are much more aggressive than the primary tumors from which they originate. Since both CSC and chemoresistant cancer cells may share common qualities and implicate involvement of mitochondria, drugs inducing mitochondrial dysfunction as for example, bactericidal antibiotics, may effectively suppress growth of cancer cells. In the current study, we demonstrate that CSC and chemoresistant cells derived from triple negative breast cancer (TNBC) cells display enrichment of up- and down-regulated proteins from metabolic pathways that suggest a direct link to mitochondria. Both cancer cell types (resistant cells and CSC) can be targeted by antibiotics, in particular, linezolid which decreases tumour growth rate by suppressing mitochondrial functions. As autophagy itself can “feed” cancer cells in their trial to reduce ROS induction by antibiotics, we propose that specific bactericidal antibiotics used in combination with autophagy blocker may suppress cancer cell proliferation and decrease tumour growth.