High mitochondrial DNA levels accelerate lung adenocarcinoma progression

Menée à l'aide de modèles murins transgéniques d'adénocarcinome du poumon, cette étude met en évidence un mécanisme par lequel un nombre élevé de copies de l'ADN mitochondrial dans les cellules cancéreuses accélère la progression tumorale

Résumé en anglais

Lung adenocarcinoma is a common aggressive cancer and a leading cause of mortality worldwide. Here, we report an important in vivo role for mitochondrial DNA (mtDNA) copy number during lung adenocarcinoma progression in the mouse. We found that lung tumors induced by KRASG12D expression have increased mtDNA levels and enhanced mitochondrial respiration. To experimentally assess a possible causative role in tumor progression, we induced lung cancer in transgenic mice with a general increase in mtDNA copy number and found that they developed a larger tumor burden, whereas mtDNA depletion in tumor cells reduced tumor growth. Immune cell populations in the lung and cytokine levels in plasma were not affected by increased mtDNA levels. Analyses of large cancer databases indicate that mtDNA copy number is also important in human lung cancer. Our study thus reports experimental evidence for a tumor-intrinsic causative role for mtDNA in lung cancer progression, which could be exploited for development of future cancer therapies. High mtDNA levels increase tumor burden in mice through enhanced mitochondrial respiratory chain capacity.