Neale M L, Matthews N
Department of Medical Microbiology, University of Wales College of Medicine, Heath Park, Cardiff, UK.
Br J Cancer. 1990 Jun;61(6):831-5. doi: 10.1038/bjc.1990.186.
The tumour cell lines U937A and L929 form large, loosely packed colonies in vitro and can be killed by the cytokine tumour necrosis factor (TNF). In contrast, their TNF-resistant mutants U937A/R and L929/R form tightly packed colonies. Since cells which form loose colonies have increased metastatic potential it is important to understand the factors governing colonial morphology. To this end, we have compared the extracellular matrices (ECMs) of the 'loose' lines, U937A and L929 with their 'tight' mutants. By immunofluorescence, a polyvalent anti-U937A serum revealed a fibrillar network in the ECMs of the 'loose' lines which was absent in the 'tight'. On Western blotting of ECMs the antiserum detected an additional 300 kDa protein in the 'loose' lines which was subsequently shown to be cellular fibronectin. The four lines secreted comparable amounts of fibronectin and this was qualitatively indistinguishable between 'loose' and 'tight' cells by peptide mapping or lectin binding. It is concluded that the differences in colonial morphology are due to the 'tight' mutants' inability to incorporate fibronectin into the ECM.
肿瘤细胞系U937A和L929在体外形成大的、松散堆积的集落，并且可被细胞因子肿瘤坏死因子（TNF）杀死。相比之下，它们的TNF抗性突变体U937A/R和L929/R形成紧密堆积的集落。由于形成松散集落的细胞具有更高的转移潜能，因此了解控制集落形态的因素很重要。为此，我们比较了“松散”细胞系U937A和L929与其“紧密”突变体的细胞外基质（ECM）。通过免疫荧光，一种多价抗U937A血清在“松散”细胞系的ECM中显示出纤维状网络，而在“紧密”细胞系中则不存在。在ECM的蛋白质印迹分析中，该抗血清在“松散”细胞系中检测到一种额外的300 kDa蛋白质，随后证明其为细胞纤连蛋白。这四种细胞系分泌相当数量的纤连蛋白，并且通过肽图谱分析或凝集素结合在“松散”和“紧密”细胞之间在质量上无法区分。得出的结论是，集落形态的差异是由于“紧密”突变体无法将纤连蛋白整合到ECM中。
