Naugler Christopher T
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.
Theor Biol Med Model. 2010 Nov 9;7:42. doi: 10.1186/1742-4682-7-42.
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.
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.
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.
肿瘤内存在的各种癌细胞克隆的种群动态十分复杂，目前仍知之甚少。癌细胞克隆可被视为同域无性繁殖物种，因此，应用与无性繁殖物种相关的理论种群遗传学可能会提供更多见解。
据估计，癌症内肿瘤细胞的代数至少为40代，但癌细胞的高死亡率表明实际的细胞代数可能多达数百代。假设单个克隆的选择优势在自由生活动物物种所报告的范围内，如此大量的代数将很容易使自然选择推动克隆进化。肿瘤细胞克隆进化也可能由不同克隆内在增殖率的差异或遗传漂变驱动。在研究的每种情况下，癌症干细胞的存在都需要较低的选择压力或内在增殖率的较小差异。
癌症干细胞的存在可能导致更快速的克隆进化。理论种群遗传学的具体预测可能会使人们对这一过程有更深入的理解。
