Induction of albumin gene transcription in hepatocytes by extracellular matrix proteins.

Transcriptional activity of the albumin gene was induced in primary cultures of hepatocytes by adding dilute concentrations of basement membrane-like proteins derived from the EHS mouse sarcoma tumor to established type I collagen cultures. By immunofluorescence microscopy with antialbumin antibody, the population of cells responded uniformly to dilute EHS. Of the three major components of EHS, purified laminin was as effective as unfractionated EHS at inducing an increase in albumin mRNA levels and albumin secretion; type IV collagen and heparan sulfate proteoglycan were ineffective.