Lagarde A E
Invasion Metastasis. 1983;3(1):52-64.
A fluctuation analysis was performed on cell populations of a nonmetastatic, wheat germ agglutinin-resistant mutant (MDW4-1) of the murine MDAY-D2 tumor in order to determine the spontaneous frequency of occurrence of metastatic revertants during in vitro proliferation. A number of clones derived from the MDW4-1 mass culture were expanded in vitro and equal samples were inoculated intravenously into groups of DBA/2 mice. The number of metastatic cells present in each clonal population was estimated on the basis of the mean survival time per animal group, by making reference to a standard dose-response relationship. The final calculation indicated that metastatic cells arise randomly in vitro at a rate of 2 X 10(-5) cell per MDW4-1 cell per generation (upper estimate). The lower estimate of the rate reveals that only few metastatic revertants preexisted prior to inoculation when wheat germ agglutinin-sensitive cells are counterselected in the presence of the lectin. We conclude that the reexpression of the metastatic potential in the MDW4-1 tumor cell line may occur spontaneously, outside the host-selective environment, and may be linked to the loss of the wheat germ agglutinin-resistance phenotype.
为了确定小鼠MDAY-D2肿瘤的非转移性、麦胚凝集素抗性突变体（MDW4-1）细胞群体在体外增殖过程中转移性回复突变体的自发出现频率，进行了波动分析。从MDW4-1大量培养物中获得的许多克隆在体外进行扩增，并将等量样品静脉注射到DBA/2小鼠组中。根据每组动物的平均存活时间，并参考标准剂量反应关系，估计每个克隆群体中存在的转移细胞数量。最终计算表明，转移细胞在体外以每代每MDW4-1细胞2×10^(-5)个细胞的速率随机产生（上限估计）。速率的下限估计表明，当在凝集素存在下对麦胚凝集素敏感细胞进行反选择时，接种前仅预先存在少数转移性回复突变体。我们得出结论，MDW4-1肿瘤细胞系中转移潜能的重新表达可能在宿主选择环境之外自发发生，并且可能与麦胚凝集素抗性表型的丧失有关。
