Metastasis suppressor genes for prostate cancer.

To examine the role of human chromosomes in the development of metastatic prostate cancer, we introduced a copy of human chromosomes into highly metastatic Dunning R-3327 rat prostatic cancer cells by microcell-mediated chromosome transfer. Each microcell hybrid clones containing human chromosomes 8, 10, 11, and 17, respectively, showed decreased ability to metastasize to the lung, without any loss of tumorigenicity. This finding demonstrates that these human chromosomes contain metastasis suppressor genes for prostate cancer. Spontaneous deletion of portions of human chromosomes was observed in human chromosome 10, 11, and 17 studies. In the human chromosome 8 study, irradiated microcell-mediated chromosome transfer was performed to enrich chromosomal arm deletions of human chromosome 8. Relationships between the size of human chromosomes introduced into microcell hybrid clones and the number of lung metastases produced by the clones were analyzed to determine which part of human chromosomes contained metastasis suppressor gene(s) for prostate cancer. Molecular and cytogenetic analyses of microcell hybrid clones demonstrated that metastasis suppressor genes on human chromosomes 8, 10, and 11 were located on 8p23-q12, 10q, 11p13-11.2, respectively. Further analyses are proposed to confirm the potentially useful advantage of this assay system to identify metastasis suppressor gene(s) for prostate cancer.