These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Differential responsiveness of normal and simian virus 40-transformed BALB/c 3T3 cells to retinoic acid: rapid enhancement of epidermal growth factor receptor binding in a simian virus 40-3T3 variant.
    Author: Chen JK, Li LW, Mioh H.
    Journal: Cancer Res; 1987 Oct 01; 47(19):4995-9. PubMed ID: 3040236.
    Abstract:
    The effects of retinoic acid on the epidermal growth factor (EGF) receptor binding and cell growth of normal and simian virus 40 (SV40)-transformed BALB/c 3T3 cells were compared under identical culture conditions. Retinoic acid induced a rapid enhancement of EGF binding to SV40-transformed cells. Half-maximal enhancement occurred at about 7 h after the cells were exposed to 20 ng/ml of retinoic acid, and maximal stimulation (from 2.5- to 3.5-fold over the control) was obtained after 12 h of exposure. The kd of the control and retinoic acid-treated cells was calculated to be 8.0 X 10(-10) M and 8.2 X -10 M, respectively. However, the number of unoccupied EGF binding sites increased from 0.98 X 10(4) to 2.28 X 10(4) per cell. Normal 3T3 cells would not respond to retinoic acid unless they were cultured in serum-containing medium. After 96 h of exposure, only a 50% enhancement of EGF binding was observed. The EGF receptor number of the untreated normal cells was calculated to be 1.82 X 10(4) per cell, twice the number expressed by untreated SV40-transformed cells. The increase of EGF receptor number caused by retinoic acid in SV40-transformed cells was blocked by either actinomycin D or cycloheximide treatment. These results indicated that SV40 transformation of BALB/c 3T3 cells altered the regulatory mechanism governing the complement of cell surface EGF receptors.
    [Abstract] [Full Text] [Related] [New Search]