COORDINATE EXPRESSION OF C-FOS, P53 AND CYTOKERATIN GENES DURING THE ALTERATION OF GROWTH OF HUMAN HEPATOMA-CELLS - MESSENGER-RNA LEVELS MEASURED BY REVERSE TRANSCRIPTION AND POLYMERASE CHAIN-REACTION

Teleocidin, a tumor promoter, inhibited the proliferation, enhanced cytokeratin assembly and increased the type III procollagen production of PLC/PRF/5 hepatoma cells. Teleocidin transiently increased the levels of c-fos and p53 mRNAs measured by reverse transcription and polymerase chain reaction. This was followed by a reduction of c-myc mRNA and an increase of cytokeratin mRNA. The level of p120 mRNA was not remarkably altered. Sequential alterations of the expression of c-fos, p53, c-myc and cytokeratin genes induced by teleocidin may be responsible for the morphological and functional changes of hepatoma cells induced by this tumor promoter.