Pathogenic Heteroplasmic Somatic Mitochondrial DNA Mutation Confers Platinum-Resistance and Recurrence of High-Grade Serous Ovarian Cancer

Platinum resistance is a primary barrier to improving the survival rate of ovarian cancer. The relationship between mtDNA somatic mutations and response to platinum-based chemotherapy in ovarian cancer has not been well clarified. Here, we employed the next-generation sequencing (NGS) platform to identify mtDNA mutations of the unrelated high-grade serous ovarian cancer (HGSOC) patients. We identified 569 germline variants and 28 mtDNA somatic mutations, and found the platinum-sensitive relapsed HGSOC patients had more synonymous mutations while the platinum-resistant relapsed HGSOC patients had more missense mutations in the mtDNA somatic mutations. Meanwhile, we found that the HGSOC patients who harbored heteroplasmic pathogenic mtDNA somatic mutations had significantly higher prevalence of both platinum-resistance and relapse than those without (80.0% versus 16.7%, p=0.035). Additionally, we observed that the tumor tissues had significantly higher lactate-to-pyruvate (L/P) ratio than the paired nontumor tissues (p