It was previously reported that the stroma of ductal infiltrating carcinoma (DIC) of the human breast contains considerable amount of an embryo-foetal collagen type, OF/LB (onco-foetal/laminin-binding), and that adhesion of 8701-BC DIC cells onto OF/LB collagen substrates selectively promotes cell growth, motility, production of extracellular lytic enzymes and invasion "in vitro" if compared with other collagen species. To detect possible transcriptional differences for regulatory proteins following OF/LB collagen-cell interactions, we submitted RNA preparations from 8701-BC cells grown on collagen type I, IV and OF/LB to "differential display"-PCR in the presence of degenerate C(2)H(2) zinc finger and protein tyrosine kinase domain oligonucleotide primers. We report that growth of 8701-BC cells on OF/LB collagen is consistently associated with the up-regulation of hRPB17 gene, coding for an RNA polymerase subunit, as confirmed by conventional RT-PCR and Northern analyses.