Cell Biol Int. 1996 Aug;20(8):523-30.  

Inhibition of cellular growth and steroid 11 beta-hydroxylation in
ras-transformed adrenocortical cells by the fungal toxins beticolins.

Ding G, Maume G, Milat ML, Humbert C, Blein JP, Maume BF.

Unite associee INRA-Universite 692, Universite de Bourgogne, Dijon, France.

The proliferation of GM16 and 4CDT ras-transformed newborn rat adrenocortical
(RTAC) cells and Y1 mouse adrenal tumor cells was inhibited by beticolins, the
fungal toxins extracted from Cercospora beticola, at submicromolar
concentrations in a dose-dependent manner. Inhibitory concentrations for half
the maximum inhibition were 150, 75 and 25 nM for beticolin-1 and 230, 150 and
50 nM for beticolin-2 in GM16, 4CDT and Y1 cells respectively. Beticolins
strongly inhibited the production of 11 beta-hydroxysteroids on the second and
third days of treatment in a dose-dependent manner between 0.1 and 1 microM.
Beticolins were shown by confocal microscopy to be localized in cytoplasmic
organelles about 30-40 min after treatment. This finding favors a direct action
of beticolins on mitochondrial steroid 11 beta-hydroxylase albeit another less
direct mechanism involving a cytoplasmic signaling pathway cannot be excluded.

PMID: 8938985 [PubMed - indexed for MEDLINE]