[Analysis of mitochondrial DNA D-loop region mutation and its significance in human oncocytoma]

To investigate the mutation in mitochondrial DNA displacement-loop (mtDNA D-loop) region in oncocytoma and its relationship with tumorigenesis and tumor development.

The mtDNA D-Loop region of 20 thyroid or renal oncocytomas and the adjacent normal tissues were amplified by PCR, and then sequenced. Five human fetal renal tissues were collected as matched controls.

Among the 20 oncocytomas, 21 mutations which focused on hypervariable region I (HVI) were found in 7 tumor tissues and 1 normal tissue with the mutation rates of 35% and 5%, respectively. At the same time, 191 polymorphisms were found in the 20 cases.

mtDNA D-loop region, especially HV I, is the mutational hotspot of oncocytomas, which may be closely related with mtDNA duplicating rate and the function of mitochondria.