Suppression of metastasis of rat prostatic cancer by introducing human chromosome 8.

In previous allelotype analyses of human prostatic cancer specimens, allelic loss on the short arm of chromosome 8 is frequently observed. However, it is still unclear whether this allelic loss is an initial event or a later one in development of prostatic cancer. Our previous studies demonstrate that introduction of human chromosome 11 into highly metastatic rat prostatic cancer cells results in suppression of metastatic ability without suppression of the in vivo growth rate or tumorigenicity of the hybrid cells (T. Ichikawa et al. Cancer Res., 52: 3486-3490, 1992). To clarify the role of human chromosome 8 in prostatic cancer, this chromosome was introduced into highly metastatic rat prostatic cancer cells using microcell-mediated chromosome transfer. Introduction of human chromosome 8 resulted in suppression of metastatic ability of the microcell hybrids, whereas no suppression of the in vivo growth rate or tumorigenicity was observed. These results demonstrate that human chromosome 8 contains metastasis suppressor gene(s) for prostatic cancer derived from a rat. These also suggest that human chromosome 8 has an important role in development of prostatic cancer.