SUBCHROMOSOMAL MAPPING OF A PUTATIVE TRANSFORMATION SUPPRESSOR GENE ON HUMAN CHROMOSOME-1

We previously reported that the introduction of a normal human chromos ome 1 via microcell-mediated chromosome transfer suppressed the transf ormed phenotypes, including anchorage-independent growth, of Kirsten m urine sarcoma virus-transformed NIH3T3 (DT) cells. Soft-agar clones de rived from DT-#1 cells (DT cells with an intact transferred human chro mosome 1) exclusively failed to retain an intact form of this chromoso me. Thus, a gene(s) with a suppressive activity on this chromosome had probably been lost. We therefore attempted to identify a commonly del eted region on human chromosome 1 in these soft-agar clones. Although eight of the 9 soft-agar clones examined still contained regions on th is chromosome, to a greater or lesser degree, four loci on 1q21 and 1q 23-q24 were commonly lost in all of them. Furthermore, the soft-agar c lones had growth properties similar to those of DT cells. Thus, chromo some and DNA analyses suggested that human 1921 and/or 1q23-q24 carrie s a transformation suppressor gene(s) which controls the transformed p henotypes of DT cells.