Heregulin is rapidly translocated to the nucleus and its transport is correlated with c-myc induction in breast cancer cells
Li, W.; Park, J.W.; Nuijens, A.; Sliwkowski, M.X.; Keller, G.A.
Oncogene 12(11): 2473-2477
1996
ISSN/ISBN: 0950-9232 PMID: 8649790 Document Number: 457010
Heregulins (neuregulins) are a family of proteins known to interact and activate the receptor tyrosine kinases ErbB2 in association with ErbB3 or ErbB4. Using immunofluorescence microscopy, electron microscopy autoradiography, and SDS-PAGE analysis of nuclear fractions, we show that the heregulin-beta1(1-244) isoform is rapidly internalized and translocated to the nucleus of SK-BR-3 breast cancer cells as an intact molecule. Heregulin-beta 1(1-244) treatment up-regulated expression of c-myc mRNA and protein, which was also observed to undergo its own translocation from the cytosol to the nucleus. c-myc thus appears to be a cellular target gene of HRGbeta 1(1-244), and its induction may be related to the nuclear translocation of heregulin.