Experimental Transplantation of Carcinoma to Tooth Extraction Sockets: A bone invasion model

抄録

The purpose of this study was to delineate the process of bone invasion by oral carcinoma. An experimental model of oral carcinoma invading jawbone was established by transplanting mouse NR-S1 tumor or human-cultured NB-1 tumor to the tooth extraction socket. In the early stage after tumor transplantation, the tumor grew in the extraction socket and subsequently filled the socket and extended outward to the neighboring regions. Bone resorption and collagen production status, as well as HSP47 expression, were investigated in the process of the tumor invasion. Osteoclasts appeared increasingly on the surface of the corresponding bone during the early stage and then decreased in number as bone resorption with tumor invasion progressed. Enlarged osseous lacunae, as well as Haversian and Volkmann's canals, were present in the bone near the tumor, and tumor cells were also detected in the enlarged osseous spaces. Expression of HSP47 was positive for the carcinoma cells infiltrating into the bone tissue, but not for the counterparts in the mass. In summary, cells may invade bone through the osteolytic spaces and necessitate ECM around them for their nutritional supply to proliferate.