Mechanisms ofpromoting the bone invasion of cancer cells by osteopontin

我们分离了小鼠骨桥蛋白（OPN）基因，并分析了其结构和功能。此外，我们在α - 1抗胰蛋白酶启动子的控制下，产生了表达OPN的转基因（TG）小鼠。OPN含有GRGDS整合素结合域，可促进癌细胞的粘附和迁移。破骨细胞通过αvβ3和骨唾液蛋白与骨基质结合。我们在体内和体外实验中分析了OPN在癌细胞浸润和转移中的作用。作为一个结果。对sopn - tg小鼠和野生型小鼠皮下或龈内注射B16黑色素瘤细胞。两组小鼠肿瘤的生长和侵袭无显著差异。出乎意料的是，与野生型小鼠相比，OPN-TG小鼠的肺转移明显受到抑制。iv.预给药重组OPN显著抑制黑色素瘤细胞的肺转移。2. 重组蛋白的构建及含OPN2功能域的合成肽。为了构建重组蛋白，我们制备了编码功能片段的gst融合dna并将其转染到大肠杆菌中。但是，没有证实蛋白质的产生。因此，我们制作了一些带有或不带有Arg-Gly-Asp序列的肽。在初步实验中，在含有Arg-Gly-Asp序列的肽上观察到肺肿瘤菌落数量的显著减少。

We isolated the mouse osteopontin(OPN) gene and analyzed its structure and function. Furthermore, we generated transgenic(TG) mice expressing OPN under the control of the α1-anti-trypsin promoter. OPN contains a GRGDS integrin-binding domain and is shown to promote the adhesion and migration of cancer cells. Osteoclasts have been shown to bind to bone matrix via αvβ3 and bone sialoprotein for attachment.We analyzed the role of OPN under the infiltration and metastasis of cancer cells in vivo and in vitro. As a result1. Bone infiltration and lung metastasis of cancer cellsOPN-TG mice and wild-type mice were given subcutaneous or intra-gingival injections of B16 melanoma cells. There was no significant difference of tumor growth and invasion between two groups of mice. Unexpectedly, significant inhibition of lung metastases in OPN-TG mice was observed as compared with the wild-type mice. The iv. pre-administration of recombinant OPN significantly inhibited the lung metastases with melanoma cells. 2. Construction of recombinant proteins and synthetic peptides possessing a functional domain derived from OPN2. Construction of recombinant proteins and synthetic peptides possessing a functional domain derived from OPNTo construct a recombinant proteins, the GST-fusion DNAs encoding the putative functional fragments were made and transfected into E. coli. But, no production of protein was confirmed. We therefore made some peptides with or without an Arg-Gly-Asp sequence. In preliminary experiment, a significant reduction in the number of lung tumor colonies was observed at a peptide containing Arg-Gly-Asp sequence.