Sheridan J W, Finlay-Jones J J
J Cell Physiol. 1979 May;99(2):247-59. doi: 10.1002/jcp.1040990212.
A transplantable methylcholanthrene-induced fibrosarcoma of female BALB/c mice (the MC-2 fibrosarcoma) was dissociated by combined mechanical and enzymatic means, then fractionated by isopycnic centrifugation in linear albumin gradients. In some experiments recovered cells were both cultured in soft nutrietn agar and inoculated subcutaneously into syngeneic recipients. In these experiments a highly significant correlation was observed between subsequtnt colony number and rapid growth phase tumor size suggesting identity of clonigenic and tumorigenic cells. It was consistently found that clonigenic cells were markedly depleted from the low density extremes of the cell density distribution profiles suggesting that the low density neoplastic cells had irreversibly left the growth fraction. With increasing tumor age, sequential studies showed that both total and clonigenic cell density distribution profiles were variable, showing no obvious trend, suggesting that in the age (13-35 days) and size (2-8 g) range studied growth fraction changes had little selective effect on cells of any specific density. These results imply that a marked selective depletion of low density clonigenic cells (or selective accumulation of low density non-proliferative cells) must mainly occur during an earlier phase of tumor growth. Studies on several other murine solid tumors also showed maximal depletion of clonigenic cells from the least dense fractions, suggesting that this situation may be common.
通过机械和酶促联合方法解离雌性BALB/c小鼠的可移植性甲基胆蒽诱导纤维肉瘤（MC-2纤维肉瘤），然后在线性白蛋白梯度中通过等密度离心进行分级分离。在一些实验中，回收的细胞既在软营养琼脂中培养，也皮下接种到同基因受体中。在这些实验中，观察到后续集落数与快速生长阶段肿瘤大小之间存在高度显著的相关性，表明克隆原性细胞和致瘤性细胞具有同一性。一直发现，克隆原性细胞在细胞密度分布曲线的低密度极端处明显减少，这表明低密度肿瘤细胞已不可逆地离开了生长分数。随着肿瘤年龄的增加，连续研究表明，总细胞密度分布曲线和克隆原性细胞密度分布曲线都是可变的，没有明显趋势，这表明在所研究的年龄（13 - 35天）和大小（2 - 8克）范围内，生长分数的变化对任何特定密度的细胞几乎没有选择性影响。这些结果意味着低密度克隆原性细胞的显著选择性减少（或低密度非增殖性细胞的选择性积累）必定主要发生在肿瘤生长的早期阶段。对其他几种小鼠实体瘤的研究也表明，克隆原性细胞在密度最低的部分减少最多，这表明这种情况可能很常见。
