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: Structure-dependent induction of aryl hydrocarbon hydroxylase in human breast cancer cell lines and characterization of the Ah receptor.
    Author: Harris M, Piskorska-Pliszczynska J, Zacharewski T, Romkes M, Safe S.
    Journal: Cancer Res; 1989 Aug 15; 49(16):4531-5. PubMed ID: 2545344.
    Abstract:
    The structure-dependent induction of aryl hydrocarbon hydroxylase (AHH) and ethoxyresorufin O-deethylase by 2,3,7,8-tetrachlorodibenzo-p-dioxin, 2,3,7,8-tetrachlorodibenzofuran, and 1,2,4,7,8-pentachlorodibenzo-p-dioxin was determined in the MCF-7, T47-D, and MDA-MB-231 human breast cancer cell lines. Both the MCF-7 and T47-D cells were responsive to the induction effects of the halogenated aryl hydrocarbons and the structure-induction relationships were comparable to the reported structure-activity (induction, receptor binding, and toxicity) relationships observed in rodents and rodent cells in culture. The induction of ethoxyresorufin O-deethylase in the T47-D cells was the most sensitive aryl hydrocarbon (Ah) receptor-mediated response in both cell lines and this enzyme activity was more inducible than aryl hydrocarbon hydroxylase. In contrast, the three congeners were inactive as monooxygenase enzyme inducers in the MDA-MB-231 cells. Despite the differential Ah responsiveness of the cell lines, incubation of the cells with [3H]-2,3,7,8-tetrachlorodibenzo-p-dioxin followed by extraction of the nuclei with high salt and velocity sedimentation analysis of the extracts showed that specifically bound nuclear Ah receptor complexes were present in the three cell lines. The sedimentation coefficients (and levels) for the nuclear receptors were 6.6 S (32.1 fmol/mg protein/mg DNA), 6.9 S (61.6 fmol/mg protein/mg DNA), and 7.4 S (38.2 fmol/mg protein/mg DNA) in the T47-D, MCF-7, and MDA-MB-231 cell lines, respectively. Cytosolic receptor was also detected in the MCF-7 and MDA-MB-231 cells. Thus, despite the differences in Ah responsiveness of the T47-D and MDA-MB-231 cells, comparable levels of nuclear receptor were detected in both cell lines. Furthermore, the elution profiles of the nuclear receptors from DNA-Sepharose columns by using a salt gradient were similar and this suggested that defects in the DNA-binding activity of MDA-MB-231 nuclear receptor complexes were not major factors associated with their failure to respond to 2,3,7,8-tetrachlorodibenzo-p-dioxin and related compounds.
    [Abstract] [Full Text] [Related] [New Search]