Factors that determine cell-specific gene expression in pancreatic endocrine tumor cells.
Phenotypically distinct islet tumor cell lines may recapitulate certain of the developmental pathways of normal islet cell differentiation by expressing a combinatorial set of positively and negatively acting DNA-binding proteins to allow for the programmed expression of genes encoding polypeptide hormones. The structure of one of these DNA-binding proteins, a cyclic AMP-responsive protein (CREB) that binds specific DNA regulatory elements in the somatostatin gene, has been deduced from the sequence of a cloned cDNA. The CREB protein contains a DNA-binding domain separate from a cAMP-dependent protein kinase A activation domain. Further characterizations of the genes encoding the DNA-binding proteins should help to elucidate the cellular processes involved in islet cell differentiation and the genesis of tumors.
Habener
J F
JF
Laboratory of Molecular Endocrinology, Massachusetts General Hospital, Harvard Medical School, Boston.
Vallejo
M
M
Hoeffler
J P
JP
D007516:Adenoma, Islet Cell / Q000235:genetics* / Q000648:ultrastructure; D000818:Animals; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D010190:Pancreatic Neoplasms / Q000235:genetics* / Q000648:ultrastructure