Mutations in the mitochondrial DNA D-Loop region occur frequently in human osteosarcoma

To explore the polymorphisms and mutations of mitochondrial D-Loop region in osteosarcoma and their possible association with carcinogenesis, direct DNA sequencing method was used to detect the variants of the mitochondrial D-Loop in 20 patients with osteosarcoma. We found mutations of the mitochondrial D-Loop in 14/20 (70%) of the tested osteosarcoma samples, including 34 novel mutations. We did not detect any new polymorphisms in osteosarcomas, nor was there any association between variants and the three histopathological subtypes. We identified 89 variant sites, most of which were within the hypervariable I and II (HV I and HV II) regions. These data suggest that mtDNA mutations within the D-Loop region, particularly the HV I and HV II segments, are a frequent event in osteosarcomas.