SUPPRESSION OF TUMORIGENICITY OF BREAST-CANCER CELLS BY TRANSFER OF HUMAN-CHROMOSOME-17 DOES NOT REQUIRE TRANSFERRED BRCA1 AND P53 GENES

A number of candidate tumor suppressor genes located on the human chro mosome 17 are thought to have a role to play in the development of bre ast cancer. In addition to the p53 gene on 17p13.1 and the BRCA1 gene mapped to 17q12-21, other chromosomal regions for tumor suppressor gen es have been suggested to exist on 17p13.3 and both the central and th e distal parts of 17q, although definitive functional proof of their i nvolvement in breast cancer tumorigenesis is still lacking. In this re port we show that microcell transfer of a human chromosome 17 into wil d-type p53 breast cancer cells CAL51 results in loss of tumorigenicity and anchorage-independent growth, changes in cell morphology and a re duction of cell growth rates of the neo-selected microcell hybrids. In the hybrid cells, which express the p53 wild-type protein, only the p - and the distal parts of the q arm of donor chromosome 17 are transfe rred. Thus, our results provide functional evidence for the presence o f one or more tumor suppressor gene(s) on chromosome 17, which are dis tinct from the p53 and the BRCA1 genes.