RESUMO
<p><b>OBJECTIVE</b>To investigate variations of mtDNA in mouse tumors and to explore the relationship between mtDNA mutations and murine carcinogenesis.</p><p><b>METHODS</b>Variations of D-loop, ND3 and tRNAIle + Glu + Met gene fragments of mtDNA from six mouse tumor cell lines were analyzed by PCR-RFLP and PCR-SSCP techniques.</p><p><b>RESULTS</b>ND3 and tRNAIle + Glu + Met gene fragments of mtDNA from the tumors showed no variations at 27 endonuclease sites. The D-loop of mtDNA from Hca-F demonstrated an additional endonuclease site of Hinf I in contrast to the inbred mouse. Upon PCR-SSCP analysis, the D-loop of mtDNA was found to possess mutations in 4 of 6 tumors.</p><p><b>CONCLUSION</b>D-loop appears to be the hot spot for tumor mtDNA mutations, which may contribute to the carcinogenesis of murine tumors.</p>