Restriction of the rat-specific RNS sequences of Ki-MSV to the nucleus of dibutyryl cyclic AMP-treated K-A31 cells.

The treatment of oncogenically transformed cells in culture, with dibutyryl cyclic AMP (cAMP) has, in many cases, resulted in a general phenotypic change towards the normal state. A virus-specific gene product(s) is responsible for the transformation of cells by sarcoma viruses and it has been suggested that the src gene product may act through the alteration of cAMP levels. With these premises we have studied the effects of dibutyryl cAMP on cell growth and virus genome expression in a Kirsten sarcoma virus-transformed mouse cell line. Our results suggest that certain virus-specific RNA sequences are restricted to the nucleus of these cells after several days of growth in medium containing dibutyryl cAMP and that these sequences appear to be those coding for the sarcoma information.