Simultaneous expression of salivary and pancreatic amylase genes in cultured mouse hepatoma cells.
The tissue-specific expression of two types of mouse amylase genes does not overlap in vivo; the Amy-1 locus is transcribed in the parotid gland and the liver, while expression of Amy-2 is limited to the pancreas. We identified a mouse hepatoma cell line, Hepa 1-6, in which both amylase genes can be simultaneously expressed. Amy-1 is constitutively active in these cells and is inducible by dexamethasone at the level of mRNA. We demonstrated that the liver-specific promoter of Amy-1 is utilized by the dexamethasone-treated hepatoma cells, and that glucocorticoid consensus sequences are present upstream of this promoter. Amy-2 is not detectable constitutively, but can be activated if the cells are cultured in serum-free medium containing dexamethasone. Expression of Amy-2 in a nonpancreatic cell type has not previously been observed. We speculate that induction of Amy-1 and activation of Amy-2 may involve different regulatory mechanisms. Hepa 1-6 cells provide an experimental system for molecular analysis of these events.
D000681:Amylases / Q000096:biosynthesis / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D003907:Dexamethasone / Q000494:pharmacology; D004790:Enzyme Induction / Q000187:drug effects; D005796:Genes; D007527:Isoenzymes / Q000235:genetics*; D008099:Liver / Q000201:enzymology; D008114:Liver Neoplasms, Experimental / Q000201:enzymology*; D051379:Mice; D008810:Mice, Inbred C57BL; D010179:Pancreas / Q000201:enzymology*; D010306:Parotid Gland / Q000201:enzymology; D011401:Promoter Regions, Genetic / Q000187:drug effects; D012463:Saliva / Q000201:enzymology*; D014158:Transcription, Genetic
D007527:Isoenzymes; D003907:Dexamethasone; D000681:Amylases