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Biomedical subjects

C A Reilly

Publications and source records attributed to C A Reilly.

5 recordsLinked to original sources

FBJ osteosarcoma virus in tissue culture. III. Isolation and characterization of non-virus-producing FBJ-transformed cells.

Hamster and rat cell lines have been established that have been transformed by FBJ murine sarcoma virus (FBJ-MuSV) but that do not produce virus. The hamster cell line originated from an osteosarcoma that appeared in a hamster inoculated at birth with an extract of a CFNo1 mouse FBJ-osteosarcoma. The rat cell line was obtained by transferring the FBJ-MuSV genome to normal rat kidney cells in the absence of the FBJ type C virus (FBJ-MuLV), which, usually in high concentration, accompanies the FBJ-MuSV. Both transformed hamster and rat cell lines contain the FBJ-MuSV genome, which can be rescued by ecotropic and xenotropic murine type C viruses. This rescued genome produces characteristic FBJ-MuSV foci in tissue culture and, in appropriate animal hosts, induces osteosarcomas typical of those induced by FBJ-MuSV. FBJ-MuSV was isolated originally from a parosteal osteosarcoma that occurred naturally in a mouse. Since there was no previous history of passage of the agent through any other animal species, these non-virus-producing hamster and rat cells transformed by FBJ-MuSV should be very helpful in molecular studies examining the origin of spontaneous sarcoma genomes in mice.

Animals

Pathogenesis of radiation and virus-induced bone tumors.

Bone cancer can be induced by radionuclides that localize in the skeleton. Histologically, these experimentally induced tumors resemble those found naturally in man; they range from densely ossified osteogenic sarcomas to osteolytic tumors with giant cells and only a small osteoid component. Fibrosarcomas and hemangiosarcomas also can occur in some species. It has not been possible to determine the dose in terms of absorbed energy necessary for bone-tumor induction because radionuclides are not deposited uniformly, and they diminish in amount with time. Also, the precise time when irreversible noeplastic change occurs is not known. With X-rays, however, 500 rads delivered to the endosteal surface of a mouse femur has been shown to cause osteogenic sarcoma. Bone tumors can be induced in mice by viruses. FBJ osteosarcoma virus and RFB osteoma virus were obtained from spontaneous tumors; FBR osteosarcoma virus came from a radiation-induced tumor. All three are RNA viruses with C-type particle morphology, and they are propagated by injecting cell-free extracts of virus-induced tumor. All three are RNA viruses with C-type particle morphology, and they are propagated by injecting cell-free extracts of virus-induced tumor into newborn mice. Interaction studies with bone-seeking radionuclides and these viruses have led to the hypothesis that radiation produces cancer by inactivating a viral inhibitor. There is also evidence of a bone tumor virus in the human disease. The injection of cell-free extracts of human bone cancer into newborn Syrian hamsters has induced a variety of mesenchymal tumors at a rate significantly higher than in the control hamsters. Sixty tumors of this type, including 20 osteosarcomas, 11 fibrosarcomas, and 9 osteomas, have been diagnosed so far in experimental animals; in control hamsters there has been only one, a fibrosarcoma. Immunofluorescence assays and cytotoxicity studies indicated that these hamster tumors carried a human antigen.

Animals

Plasma alkaline phosphatase in mice with experimentally-induced osteosarcomas.

No statistically significant difference in alkaline phosphatase levels was demonstrated in animals injected with the FBJ virus. However, there was a significant increase associated with the development of osteosarcomas in response to the iv injection of 1.0 uCi 90 Sr/g body weight into 11-18-mo-old Anl:CFl females. It was proposed that alkaline phosphatase determinations can be used as well as roentenographic analysis to detect 90Sr-induced tumors in mice.

Alkaline Phosphatase

The etiology of osteosarcoma. A review of current considerations.

Various agents have caused osteosarcoma in several experimental animal systems. These agents or initiators may be classified as chemicals, radiation, viruses, and miscellaneous. Zinc beryllium silicate with beryllium oxide in rabbits and FBJ virus in mice are two such initiating agents. The relevance of these animal experiments to the human situation is not known, but recent reports regarding a transmissible agent obtained from human osteosarcoma tissue suggest that a virus may be implicated. There is a theoretic indication that the various etiologic agents, including viruses, may affect the DNA of normal cells in such a way that further evolution and differentiation through several cell divisions may result in the clinical appearance of cancer.

Animals