Population genetics of cancer cell clones: possible implications of cancer stem cells.
BACKGROUND
The population dynamics of the various clones of cancer cells existing within a tumour is complex and still poorly understood. Cancer cell clones can be conceptualized as sympatric asexual species, and as such, the application of theoretical population genetics as it pertains to asexual species may provide additional insights.


RESULTS
The number of generations of tumour cells within a cancer has been estimated at a minimum of 40, but high cancer cell mortality rates suggest that the number of cell generations may actually be in the hundreds. Such a large number of generations would easily allow natural selection to drive clonal evolution assuming that selective advantages of individual clones are within the range reported for free-living animal species. Tumour cell clonal evolution could also be driven by variation in the intrinsic rates of increase of different clones or by genetic drift. In every scenario examined, the presence of cancer stem cells would require lower selection pressure or less variation in intrinsic rates of increase.


CONCLUSIONS
The presence of cancer stem cells may result in more rapid clonal evolution. Specific predictions from theoretical population genetics may lead to a greater understanding of this process.
Department of Pathology and Laboratory Medicine, University of Calgary and Calgary Laboratory Services, C414, Diagnostic and Scientific Centre, 9, 3535 Research Road NW, Calgary AB, T2L 2K8 Canada. christopher.naugler@cls.ab.ca
Christopher T
CT
Naugler
D049109:Cell Proliferation; D002999:Clone Cells / Q000378:metabolism / Q000473:pathology; D040961:Genetic Drift; D014644:Genetic Variation; D006801:Humans; D009154:Mutation / Q000235:genetics; D009369:Neoplasms / Q000235:genetics* / Q000473:pathology*; D014411:Neoplastic Stem Cells / Q000378:metabolism* / Q000473:pathology*; D012641:Selection, Genetic / Q000235:genetics; D013997:Time Factors