IDENTIFICATION OF A NEURAL-SPECIFIC CDNA, NPDC-1, ABLE TO DOWN-REGULATE CELL-PROLIFERATION AND TO SUPPRESS TRANSFORMATION

Immortalized neural precursor cell lines carrying the polyoma large tu mor (T) gene have been shown previously to retain a clear-cut contact inhibition of growth and to differentiate in vitro. In the present stu dy, we have identified and isolated cDNA clones corresponding to RNA e xpressed preferentially when these cells reach confluence, One of them , NPDC-1, is expressed specifically in the nervous system, The transfe ction of dividing cells with a NPDC-1 expression vector results in the inhibition of cell proliferation. In addition, the stable introductio n of NPDC-1 into transformed cells, even of nonneural origin, leads to the suppression of transformed characteristics.