An intrinsic thymic epithelial abnormality is responsible for the spontaneous development of predominantly lymphocytic thymomas in BUF/Mna rats.
The nature of tumorigenesis of predominantly lymphocytic thymoma was examined using an animal model. Rats of the inbred BUF/Mna strain were found spontaneously to develop predominantly lymphocytic thymomas, histologically indistinguishable from their human counterparts, at an incidence of virtually 100%. Thymic rudiments of BUF/Mna rats grafted 17 months previously under the renal capsule of young athymic ACI/NMs-rnu/rnu rats also gave rise to similar lesions. The lymphocytes in the thymomas expressed T-cell antigens (rat Lyt-1 and Lyt-2.3), as in the normal case, and ACI rat specific antigen. When BUF/Mna rats of thymoma age were irradiated with a lethal dose of 12 Gy and then received a single injection of bone marrow cells (8 x 10(7)) from BALB/c-nu/nu mice, thymomas were re-formed three weeks later (in 2 of 5 rats) with the replacement lymphocytes expressing mouse Thy-1.2 antigen. These results indicate that an intrinsic thymic epithelial abnormality is responsible for the development of predominantly lymphocytic thymomas in BUF/Mna rats.
Taguchi
O
O
Laboratory of Experimental Pathology, Aichi Cancer Center Research Institute, Nagoya.
Kontani
K
K
Ikeda
H
H
Matsuyama
M
M
D000818:Animals; D016026:Bone Marrow Transplantation; D004195:Disease Models, Animal; D008214:Lymphocytes / Q000473:pathology*; D051379:Mice; D008807:Mice, Inbred BALB C; D051381:Rats; D011915:Rats, Inbred BUF; D011916:Rats, Inbred F344; D011923:Rats, Nude; D013370:Subrenal Capsule Assay; D013945:Thymoma / Q000209:etiology* / Q000473:pathology; D013950:Thymus Gland / Q000473:pathology*; D014183:Transplantation, Heterologous