Mutations of mitochondrion DNA in mouse tumors

ObjectiveTo ascertain the variations of mitochondrion DNA (mtDNA) in mouse tumors and to inquire into the relationship between mutations of mtDNA and carcinogenesis.MethodsThe variations of D-loop, ND3 and tRNA^Met+Glu+Ile gene fragments of mtDNA from six tumor cell lines of mice were analyzed by PCR technology with restriction fragment length polymorphism analysis (polymerase chain reaction-restriction fragment length polymorphism, PCR-RFLP) and single strand conformation polymorphism analysis (SSCP-PCR) method.ResultsND3 and tRNA^Met+Glu+Ile gene fragments of mtDNA from the tumors showed no variation in 27 endonuclease sites; D-loop of mtDNA from Hca-F had an additional endonuclease sites of Hinf I in contrast to that of the inbred mouse. Deeply analyzed by PCR-SSCP, the D-loop of mtDNA was found to possess mutations in 4 of 6 tumors.ConclusionD-loop is the hot spot of tumor mtDNA mutation which can act as contributors to the carcinogenic process.