Fernandes Russell J, Harkey Michael A, Weis Maryann, Askew Jennifer W, Eyre David R
Department of Orthopaedics and Sports Medicine, Box 356500, University of Washington, Seattle, WA 98195-6500, USA.
Bone. 2007 May;40(5):1343-51. doi: 10.1016/j.bone.2007.01.011. Epub 2007 Jan 25.
The human osteosarcoma-derived cell line, SAOS-2, exhibits many of the phenotypic characteristics of osteoblasts including the deposition of types I and V collagens in an extracellular matrix. Lesser amounts of collagen XI chains were also detected. The cell layer collagen contains hydroxylysyl pyridinoline cross-links but without the accompanying lysyl pyridinoline typical of human bone collagen. This indicates that the lysine residues at the two helical cross-linking loci are fully hydroxylated. The isoform of lysyl hydroxylase, LH1, known to be required for full hydroxylation at these sites, was shown to be highly expressed by SAOS-2 cells. Our findings provide insight on the mechanism of post-translational overmodification of lysine residues in collagen made by osteosarcoma tumors, and may be relevant for understanding a similar overmodification observed in osteoporotic bone.
人骨肉瘤衍生细胞系SAOS-2表现出许多成骨细胞的表型特征，包括在细胞外基质中沉积I型和V型胶原蛋白。还检测到少量的XI型胶原链。细胞层胶原蛋白含有羟赖氨酰吡啶交联，但没有人类骨胶原蛋白特有的赖氨酰吡啶交联。这表明两个螺旋交联位点的赖氨酸残基已完全羟基化。已知在这些位点进行完全羟基化所需的赖氨酰羟化酶同工型LH1，在SAOS-2细胞中高度表达。我们的研究结果为骨肉瘤肿瘤产生的胶原蛋白中赖氨酸残基的翻译后过度修饰机制提供了见解，可能有助于理解在骨质疏松性骨中观察到的类似过度修饰。
