Mutations of mitochondrion DNA in mouse tumors

Objective： To ascertain the variations of mitochondrion DNA （mtDNA） in mouse tumors and to inquire into the relationship between mutations of mtDNA and carcinogenesis Methods： The 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. Results： ND3 and tRNA^Met＋Glu＋Ile gene fragments ofmtDNA from the tumors showed no variation in 27 endonuclease sites; D-loop ofmtDNA 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 ofmtDNA was found to possess mutations in 4 of 6 tumors. Conclusion： D-loop is the hot spot of tumor mtDNA mutation which can act as contributors to the carcinogenic