EXPRESSION OF DIFFERENT MITOGEN-REGULATED PROTEIN PROLIFERIN MESSENGER-RNAS IN EHRLICH CARCINOMA-CELLS/

Results from in vivo and from serum-free primary cultures of Ehrlich c ells suggest that the expression of mitogen-regulated protein/prolifer in (MRP/PLF) mRNAs is not essential for proliferation of this murine t umor. Two sizes for MRP/PRL-related open reading frames (ORFs) have be en detected by reverse transcription/PCR amplification. They are almos t identical to that reported for PLF-1; but 20% of the amplified cDNA included a shorter ORF, which lacks the entire sequence corresponding to that of the exon 3 of the mrp/plf genes. Ehrlich carcinoma may repr esent a good model to study regulation of expression and physiological roles of MRP/PLFs in vivo.