TRANSFORMATION OF NIH 3T3 CELLS AND SW-48 0 CELLS DISPLAYING A K-RAS MUTATION/

The spontaneous release of a glyconucleoprotein complex in the superna tant of eukaryote cell cultures is a general phenomenon independant of cell lysis. The DNA recovered from this glyconucleoprotein material c ontains most part of the genome. The SW 480 cell line, originating fro m a human colon carcinoma presents a point mutation of the K-ras gene on both alleles. These cells in culture release the mutated K-ras gene . When crude SW 480 cell supernatant is given, without any other adjon ction, to NIH/3T3 mouse cells, transformed foci appear as numerous as those occuring after a transfection provoked by a cloned E.J. ras gene administered as a calcium precipitate. The presence of a mutated ras gene in the transfected foci of the 3T3 cells has been checked by hybr idization, after PCR, with an oligonucleotide probe specific to the mu tation. This result was confirmed by sequencing the PCR product.