Autonomous derivatives of estrogen-induced renal carcinomas and spontaneous renal tumors in the Syrian hamster.

carcinomas, all of which are available in a liquid nitrogen tumor bank, are included. Although androgen inhibits estrogen tumorigenesis in the Syrian hamster kidney, it can be substituted successfully for estrogen in maintaining growth of early transplant serial passages. In such transplants hormone dependency is usually lost between the 12th and 20th serial passages (autonomy). These autonomous derivatives of hor mone-dependent renal tumors retain responsiveness to some steroidal hormones to varying extents. None of them has been as completely autonomous, i.e., hormone unresponsive, as the renal carcinoma of "spontaneous" origin. Although removal of