PMID- 10070056
OWN - NLM
STAT- MEDLINE
DCOM- 19990415
LR  - 20190205
IS  - 0002-9513 (Print)
IS  - 0002-9513 (Linking)
VI  - 276
IP  - 3
DP  - 1999 Mar
TI  - Interaction of asparagine and EGF in the regulation of ornithine decarboxylase in 
      IEC-6 cells.
PG  - G773-80
LID - 10.1152/ajpgi.1999.276.3.G773 [doi]
AB  - Our laboratory has shown that asparagine (ASN) stimulates both ornithine 
      decarboxylase (ODC) activity and gene expression in an intestinal epithelial cell 
      line (IEC-6). The effect of ASN is specific, and other A- and N-system amino 
      acids are almost as effective as ASN when added alone. In the present study, 
      epidermal growth factor (EGF) was unable to increase ODC activity in cells 
      maintained in a salt-glucose solution (Earle's balanced salt solution). However, 
      the addition of ASN (10 mM) in the presence of EGF (30 ng/ml) increased the 
      activity of ODC 0.5- to 4-fold over that stimulated by ASN alone. EGF also showed 
      induction of ODC with glutamine and alpha-aminoisobutyric acid, but ODC induction 
      was maximum with ASN and EGF. Thus the mechanism of the interaction between ASN 
      and EGF is important for understanding the regulation of ODC under physiological 
      conditions. Therefore, we examined the expression of the ODC gene and those for 
      several protooncogenes under the same conditions. Increased expression of the 
      genes for c-Jun and c-Fos but not for ODC occurred with EGF alone. The addition 
      of ASN did not further increase the expression of the protooncogenes, but the 
      combination of EGF and ASN further increased the expression of ODC over that of 
      ASN alone. Western analysis showed no significant difference in the level of ODC 
      protein in Earle's balanced salt solution, ASN, EGF, or EGF plus ASN. Addition of 
      cycloheximide during ASN and ASN plus EGF treatment completely inhibited ODC 
      activity without affecting the level of ODC protein. These results indicated that 
      1) the increased expression of protooncogenes in response to EGF is independent 
      of increases in ODC activity and 2) potentiation between EGF and ASN on ODC 
      activity may not be due to increased gene transcription but to posttranslational 
      regulation and the requirement of ongoing protein synthesis involving a specific 
      factor dependent on ASN.
FAU - Ray, R M
AU  - Ray RM
AD  - Department of Physiology and Biophysics, University of Tennessee, Memphis, 
      College of Medicine, Memphis, Tennessee 38163, USA. rray@physio1.utmem.edu
FAU - Viar, M J
AU  - Viar MJ
FAU - Patel, T B
AU  - Patel TB
FAU - Johnson, L R
AU  - Johnson LR
LA  - eng
GR  - DK-16505/DK/NIDDK NIH HHS/United States
GR  - HL-48308/HL/NHLBI NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Am J Physiol
JT  - The American journal of physiology
JID - 0370511
RN  - 0 (Ornithine Decarboxylase Inhibitors)
RN  - 0 (Protein Synthesis Inhibitors)
RN  - 0 (RNA, Messenger)
RN  - 1CC1JFE158 (Dactinomycin)
RN  - 62229-50-9 (Epidermal Growth Factor)
RN  - 7006-34-0 (Asparagine)
RN  - 98600C0908 (Cycloheximide)
RN  - EC 4.1.1.17 (Ornithine Decarboxylase)
RN  - W36ZG6FT64 (Sirolimus)
SB  - IM
MH  - Animals
MH  - Asparagine/*pharmacology
MH  - Cell Line
MH  - Cycloheximide/pharmacology
MH  - Dactinomycin/pharmacology
MH  - Drug Stability
MH  - Epidermal Growth Factor/*pharmacology
MH  - Intestinal Mucosa/cytology/enzymology
MH  - Ornithine Decarboxylase/genetics/*metabolism
MH  - Ornithine Decarboxylase Inhibitors
MH  - Protein Synthesis Inhibitors/pharmacology
MH  - RNA, Messenger/metabolism
MH  - Sirolimus/pharmacology
EDAT- 1999/03/10 00:00
MHDA- 1999/03/10 00:01
CRDT- 1999/03/10 00:00
PHST- 1999/03/10 00:00 [pubmed]
PHST- 1999/03/10 00:01 [medline]
PHST- 1999/03/10 00:00 [entrez]
AID - 10.1152/ajpgi.1999.276.3.G773 [doi]
PST - ppublish
SO  - Am J Physiol. 1999 Mar;276(3):G773-80. doi: 10.1152/ajpgi.1999.276.3.G773.