IN-VITRO CHARACTERIZATION OF ESTROGEN-INDUCED SYRIAN-HAMSTER RENAL TUMORS - COMPARISON WITH AN IMMORTALIZED CELL-LINE DERIVED FROM DIETHYLSTILBESTROL-TREATED ADULT HAMSTER-KIDNEY

Primary diethylstilbestrol-induced kidney tumors from Syrian hamsters were grown in vitro and maintained in culture for 6 mo. Combined immun ohistochemical studies using antibodies to intermediate filaments and ultrastructural studies of tumor cells in culture exhibited characteri stics similar to tumor cells in vivo. Furthermore, the cells manifeste d transformed properties in culture; they grew both as multilayered co lonies attached to the tissue culture substrate and as floating multic ellular colonies (spheroids). When cultured cells were injected into d iethylstilbestrol-treated recipient hamsters, tumors developed at the injection sites. In contrast, renal tubules or whole kidney cortex fro m control hamsters cultured in the same medium underwent only short-te rm growth, with senescence developing after approximately 1 mo. Howeve r, cell cultures of kidney cortex from animals treated in vivo for 5 m o. with diethylstilbestrol formed a cell line. This diethylstilbestrol -induced cell line has been maintained in culture for 1.5 yr and has t he following characteristics: a) it is anchorage-dependent, b) it is n egative in in vivo tumorigenicity tests, and c) cultured cells are his tochemically and ultrastructurally similar to cultured tumor cells. Th is culture system should prove to be of use in studying hormonal carci nogenesis in vitro.