Tokunaga K, Ogose A, Endo N, Nomura S, Takahashi H E
Department of Orthopedic Surgery, Niigata University School of Medicine, Japan.
Bone. 1996 Nov;19(5):447-54. doi: 10.1016/s8756-3282(96)00253-0.
To distinguish the origin of bone-forming cells in the osteosarcoma (OST) tumor inoculated into nude mice, we have developed a novel in situ hybridization technique. The system used digoxygenin (DIG) labeled DNA probes that encoded human specific repetitive gene, Alu, and mouse specific repetitive gene, mouse L1 (m-L1). The chondrogenic and osteogenic cells in the tumor had strongly positive signals for m-L1 probe without any signals for Alu probe. The expression of bone matrix proteins was also examined by in situ hybridization. The bone-forming cells were positive for mRNAs of mouse osteonectin, osteopontin, and osteocalcin relating to calcification during bone formation, while these were negative for human mRNAs of these bone matrix proteins. The OST cells in the tumor expressed the human bone morphogenetic proteins (BMPs) mRNAs by RT-PCR. These data indicated that the mouse cells, not the human sarcoma cells, are responsible for cartilage and bone formation in the OST tumor inoculated into nude mice, and we speculated that BMPs, at least in part, could play an important role in this ossification.
为了区分接种到裸鼠体内的骨肉瘤（OST）肿瘤中骨形成细胞的来源，我们开发了一种新型原位杂交技术。该系统使用地高辛（DIG）标记的DNA探针，这些探针编码人类特异性重复基因Alu和小鼠特异性重复基因小鼠L1（m-L1）。肿瘤中的软骨生成细胞和成骨细胞对m-L1探针有强阳性信号，而对Alu探针无信号。还通过原位杂交检测了骨基质蛋白的表达。骨形成细胞对与骨形成过程中钙化相关的小鼠骨连接蛋白、骨桥蛋白和骨钙素的mRNA呈阳性，而对这些骨基质蛋白的人类mRNA呈阴性。肿瘤中的OST细胞通过RT-PCR表达人类骨形态发生蛋白（BMPs）的mRNA。这些数据表明，在接种到裸鼠体内的OST肿瘤中，是小鼠细胞而非人类肉瘤细胞负责软骨和骨的形成，并且我们推测BMPs至少在一定程度上可能在这种骨化过程中发挥重要作用。
