Review

Possibility of selection against mtDNA mutations in tumors

M Khaidakov and RJ Shmookler Reis

Department of Geriatrics, University of Arkansas for Medical Sciences, John McClellan Veterans Medical Center, 4300 West 7^th Street, Little Rock, AR 72205, USA

author email corresponding author email

Molecular Cancer 2005, 4:36doi:10.1186/1476-4598-4-36

Published:	13 September 2005

Abstract

Several studies of tumors have revealed substantial numbers of clonally expanded somatic mutations in mitochondrial DNA (mtDNA), not observed in adjacent intact tissues. These findings were interpreted as indicating the involvement of mtDNA mutations in tumorigenesis. Such comparisons, however, ignore an important confounding factor: the monoclonal origin of tumors as opposed to the highly polyclonal nature of normal tissues. Analysis of recently published data on the incidence of somatic mutations in nontumor monoclonal cells suggests that, contrary to the prevailing view, the process of tumorigenesis may be accompanied by active selection against detrimental mtDNA mutations.