对含精氨酸-甘氨酸-天冬氨酸肽具有抗脱离能力的人骨肉瘤细胞会过量产生纤连蛋白受体。
Human osteosarcoma cells resistant to detachment by an Arg-Gly-Asp-containing peptide overproduce the fibronectin receptor.
作者信息
Dedhar S, Argraves W S, Suzuki S, Ruoslahti E, Pierschbacher M D
机构信息
La Jolla Cancer Research Foundation, California 92037.
出版信息
J Cell Biol. 1987 Sep;105(3):1175-82. doi: 10.1083/jcb.105.3.1175.
MG-63 human osteosarcoma cells were selected for attachment and growth in the presence of increasing concentrations of a synthetic peptide containing the cell attachment-promoting Arg-Gly-Asp sequence derived from the cell-binding region of fibronectin. Cells capable of attachment and growth in 5-mM concentrations of a peptide having the sequence Gly-Arg-Gly-Asp-Ser-Pro overproduce the cell surface receptor for fibronectin. In contrast, these cells show no differences in the numbers of vitronectin receptor they express as compared with the parental MG-63 cells. In agreement with the resistance of the selected cells to detachment by the peptide, 25-fold more Arg-Gly-Asp-containing peptide is required to prevent the attachment of these cells to fibronectin-coated surfaces than is needed to inhibit the attachment of MG-63 cells to the same substrate. However, similar concentrations of this peptide inhibit attachment of both cell lines to vitronectin-coated surfaces. The increase in fibronectin receptor is due to an increase in the levels of mRNA encoding the fibronectin receptor. Because of the nature of the selection process, we reasoned that this increase might be due to amplification of the fibronectin receptor gene, but no increase in gene copy number was detected by Southern blot analysis. The peptide-resistant cells display a very different morphology from that of the MG-63 cells, one that has a greater resemblance to that of osteocytes. The resistant cells also grow much more slowly than the MG-63 cells. The increased fibronectin receptor and altered morphology and growth properties were stable for at least 3 mo in the absence of peptide. The enhanced expression of the fibronectin receptor on the resistant cells indicates that cells are capable of altering the amount of fibronectin receptor on their surface in response to environmental factors and that this may in turn affect the phenotypic properties of the cell.
选用MG-63人骨肉瘤细胞，使其在含有源自纤连蛋白细胞结合区域、具有促进细胞黏附作用的精氨酸-甘氨酸-天冬氨酸（Arg-Gly-Asp）序列的合成肽浓度不断增加的条件下进行黏附与生长。能够在5 mM浓度的具有甘氨酸-精氨酸-甘氨酸-天冬氨酸-丝氨酸-脯氨酸（Gly-Arg-Gly-Asp-Ser-Pro）序列的肽中黏附并生长的细胞，会过量产生纤连蛋白的细胞表面受体。相比之下，与亲代MG-63细胞相比，这些细胞所表达的玻连蛋白受体数量没有差异。与所选细胞对该肽介导的脱离具有抗性一致，要阻止这些细胞黏附到纤连蛋白包被的表面，所需的含Arg-Gly-Asp的肽量是抑制MG-63细胞黏附到相同底物所需量的25倍。然而，相似浓度的该肽可抑制这两种细胞系黏附到玻连蛋白包被的表面。纤连蛋白受体的增加是由于编码纤连蛋白受体的mRNA水平升高。鉴于选择过程的性质，我们推测这种增加可能是由于纤连蛋白受体基因的扩增，但Southern印迹分析未检测到基因拷贝数的增加。肽抗性细胞呈现出与MG-63细胞非常不同的形态，更类似于骨细胞的形态。抗性细胞的生长也比MG-63细胞慢得多。在没有肽的情况下，增加的纤连蛋白受体以及改变的形态和生长特性至少在3个月内保持稳定。抗性细胞上纤连蛋白受体的增强表达表明，细胞能够响应环境因素改变其表面纤连蛋白受体的数量，而这反过来可能会影响细胞的表型特性。
Zotero 插件