Stability of sublines in the R3327-H rat prostatic tumor

Over several years of in vivo maintenance passage the R3327-H rat prostatic tumor has given rise to nine unique sublines in our laboratory. Some have emerged under selective treatment pressure while others apparently represent spontaneous or random modulation. Each new subline embodied an altered histology, growth rate, metastatic pattern or treatment sensitivity in comparison to its parent subline. However, each has been subsequently passaged enough times to provide evidence of considerable phenotypic stability, a notable point in view of the R3327 tumor's well known potential for modulation.