Biomaterial Database

Rapid transcriptional down-regulation of c-myc expression during cyclic adenosine monophosphate-promoted differentiation of leukemic cells. 1987

A Slungaard, and D L Confer, and W H Schubach

Pharmacologic elevation of cyclic AMP (cAMP) promotes growth arrest and differentiation in a variety of transformed mammalian cells, including the HL-60 human promyelocytic leukemia cell line. However, mechanisms underlying this phenomenon are poorly understood. Because cellular oncogenes play a pivotal role in regulating proliferation and differentiation, we examined whether cAMP-promoted differentiation of HL-60 was preceded by a decrease in the expression of c-myc, a cellular oncogene both amplified and constitutively expressed in HL-60. We find that cyclic AMP elevation in HL-60 caused by three different pharmacologic regimens is followed by an abrupt, greater than 90% decrease in steady state c-myc mRNA levels within 3 h, well before detectable changes in proliferation and differentiation. This decrease, which occurs despite protein synthetic blockade, is attributable to transcriptional down-regulation of c-myc and is accompanied by changes in chromatin structure near c-myc promoter sites. Our findings establish that cAMP, a ubiquitous intracellular regulatory messenger previously known only to enhance gene transcriptional activity in higher eukaryotic cells, can also suppress transcription of a cellular oncogene, thereby suggesting a potential mechanism for cAMP-promoted differentiation.

UI	MeSH Term	Description	Entries
D009857	Oncogenes	Genes whose gain-of-function alterations lead to NEOPLASTIC CELL TRANSFORMATION. They include, for example, genes for activators or stimulators of CELL PROLIFERATION such as growth factors, growth factor receptors, protein kinases, signal transducers, nuclear phosphoproteins, and transcription factors. A prefix of "v-" before oncogene symbols indicates oncogenes captured and transmitted by RETROVIRUSES; the prefix "c-" before the gene symbol of an oncogene indicates it is the cellular homolog (PROTO-ONCOGENES) of a v-oncogene.	Transforming Genes,Oncogene,Transforming Gene,Gene, Transforming,Genes, Transforming
D002454	Cell Differentiation	Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.	Differentiation, Cell,Cell Differentiations,Differentiations, Cell
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D002772	Cholera Toxin	An ENTEROTOXIN from VIBRIO CHOLERAE. It consists of two major protomers, the heavy (H) or A subunit and the B protomer which consists of 5 light (L) or B subunits. The catalytic A subunit is proteolytically cleaved into fragments A1 and A2. The A1 fragment is a MONO(ADP-RIBOSE) TRANSFERASE. The B protomer binds cholera toxin to intestinal epithelial cells and facilitates the uptake of the A1 fragment. The A1 catalyzed transfer of ADP-RIBOSE to the alpha subunits of heterotrimeric G PROTEINS activates the production of CYCLIC AMP. Increased levels of cyclic AMP are thought to modulate release of fluid and electrolytes from intestinal crypt cells.	Cholera Toxin A,Cholera Toxin B,Cholera Toxin Protomer A,Cholera Toxin Protomer B,Cholera Toxin Subunit A,Cholera Toxin Subunit B,Choleragen,Choleragenoid,Cholera Enterotoxin CT,Cholera Exotoxin,Cholera Toxin A Subunit,Cholera Toxin B Subunit,Procholeragenoid,Enterotoxin CT, Cholera,Exotoxin, Cholera,Toxin A, Cholera,Toxin B, Cholera,Toxin, Cholera
D003609	Dactinomycin	A compound composed of a two CYCLIC PEPTIDES attached to a phenoxazine that is derived from STREPTOMYCES parvullus. It binds to DNA and inhibits RNA synthesis (transcription), with chain elongation more sensitive than initiation, termination, or release. As a result of impaired mRNA production, protein synthesis also declines after dactinomycin therapy. (From AMA Drug Evaluations Annual, 1993, p2015)	Actinomycin,Actinomycin D,Meractinomycin,Cosmegen,Cosmegen Lyovac,Lyovac-Cosmegen,Lyovac Cosmegen,Lyovac, Cosmegen,LyovacCosmegen
D003850	Deoxyribonuclease I	An enzyme capable of hydrolyzing highly polymerized DNA by splitting phosphodiester linkages, preferentially adjacent to a pyrimidine nucleotide. This catalyzes endonucleolytic cleavage of DNA yielding 5'-phosphodi- and oligonucleotide end-products. The enzyme has a preference for double-stranded DNA.	DNase I,Streptodornase,DNA Endonuclease,DNA Nicking Enzyme,DNAase I,Dornavac,Endonuclease I,Nickase,Pancreatic DNase,T4-Endonuclease II,T7-Endonuclease I,Thymonuclease,DNase, Pancreatic,Endonuclease, DNA,T4 Endonuclease II,T7 Endonuclease I
D003994	Bucladesine	A cyclic nucleotide derivative that mimics the action of endogenous CYCLIC AMP and is capable of permeating the cell membrane. It has vasodilator properties and is used as a cardiac stimulant. (From Merck Index, 11th ed)	Dibutyryl Adenosine-3',5'-Monophosphate,Dibutyryl Cyclic AMP,(But)(2) cAMP,Bucladesine, Barium (1:1) Salt,Bucladesine, Disodium Salt,Bucladesine, Monosodium Salt,Bucladesine, Sodium Salt,DBcAMP,Dibutyryl Adenosine 3,5 Monophosphate,N',O'-Dibutyryl-cAMP,N(6),0(2')-Dibutyryl Cyclic AMP,AMP, Dibutyryl Cyclic,Adenosine-3',5'-Monophosphate, Dibutyryl,Cyclic AMP, Dibutyryl,Dibutyryl Adenosine 3',5' Monophosphate,Disodium Salt Bucladesine,Monosodium Salt Bucladesine,N',O' Dibutyryl cAMP,Sodium Salt Bucladesine
D005786	Gene Expression Regulation	Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.	Gene Action Regulation,Regulation of Gene Expression,Expression Regulation, Gene,Regulation, Gene Action,Regulation, Gene Expression
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000242	Cyclic AMP	An adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and ACTH.	Adenosine Cyclic 3',5'-Monophosphate,Adenosine Cyclic 3,5 Monophosphate,Adenosine Cyclic Monophosphate,Adenosine Cyclic-3',5'-Monophosphate,Cyclic AMP, (R)-Isomer,Cyclic AMP, Disodium Salt,Cyclic AMP, Monoammonium Salt,Cyclic AMP, Monopotassium Salt,Cyclic AMP, Monosodium Salt,Cyclic AMP, Sodium Salt,3',5'-Monophosphate, Adenosine Cyclic,AMP, Cyclic,Adenosine Cyclic 3',5' Monophosphate,Cyclic 3',5'-Monophosphate, Adenosine,Cyclic Monophosphate, Adenosine,Cyclic-3',5'-Monophosphate, Adenosine,Monophosphate, Adenosine Cyclic