Targeting mitochondrial oxidative phosphorylation eradicates therapy-resistant chronic myeloid leukemia stem cells

Menée in vitro et à l'aide d'une xénogreffe de leucémie myéloïde chronique humaine, cette étude met en évidence l'intérêt de cibler la phosphorylation oxydative mitochondriale pour lever la résistance thérapeutique des cellules souches cancéreuses

Résumé en anglais

Treatment of chronic myeloid leukemia (CML) with imatinib mesylate and other second- and/or third-generation c-Abl-specific tyrosine kinase inhibitors (TKIs) has substantially extended patient survival1. However, TKIs primarily target differentiated cells and do not eliminate leukemic stem cells (LSCs)2, 3, 4. Therefore, targeting minimal residual disease to prevent acquired resistance and/or disease relapse requires identification of new LSC-selective target(s) that can be exploited therapeutically5, 6. Considering that malignant transformation involves cellular metabolic changes, which may in turn render the transformed cells susceptible to specific assaults in a selective manner7, we searched for such vulnerabilities in CML LSCs. We performed metabolic analyses on both stem cell–enriched (CD34+ and CD34+CD38−) and differentiated (CD34−) cells derived from individuals with CML, and we compared the signature of these cells with that of their normal counterparts. Through combination of stable isotope–assisted metabolomics with functional assays, we demonstrate that primitive CML cells rely on upregulated oxidative metabolism for their survival. We also show that combination treatment with imatinib and tigecycline, an antibiotic that inhibits mitochondrial protein translation, selectively eradicates CML LSCs both in vitro and in a xenotransplantation model of human CML. Our findings provide a strong rationale for investigation of the use of TKIs in combination with tigecycline to treat patients with CML with minimal residual disease.