Nuclear type II [3H]estradiol binding site ligands: inhibition of ER-positive and ER-negative cell proliferation and c-Myc and cyclin D1 gene expression.

These studies assessed the effects of 3,4-dihydroxybenzalacetone (ZN-1) and 1-(3,4-dihydroxyphenyl)-2-propanol (ZN-2) on MCF-7 cell proliferation. The compounds blocked [3H]estradiol binding to nuclear type II sites, but did not compete for [3H]estradiol binding to recombinant ERalpha or ERbeta. ZN-1 and ZN-2 inhibited the proliferation of ERalpha and ERbeta positive (MCF-7) and negative (MCF-10A) breast cells, further ruling out direct binding to ER in the mechanism of action of these compounds.

Identification of nuclear type II [(3)H]estradiol binding sites as histone H4.

[3H]Luteolin binds covalently to uterine nuclear type II sites [B. Markaverich, K. Shoulars, M.

Identification of an endocrine disrupting agent from corn with mitogenic activity.

A mitogenic agent in corncob bedding and fresh corn products disrupts sexual behavior and estrous cyclicity in rats. The mitogenic activity resides in an isomeric mixture of linoleic acid derivatives with a tetrahydrofuran ring and two hydroxyl groups (THF-diols) that include 9, (12)-oxy-10,13-dihydroxystearic acid and 10, (13)-oxy-9,12-dihydroxystearic acid. Synthetic THF-diols stimulated breast cancer cell proliferation in vitro and disrupted the estrous cycle in female rats at oral doses of approximately 0.

A novel endocrine-disrupting agent in corn with mitogenic activity in human breast and prostatic cancer cells.

Housing adult rats on ground corncob bedding impedes male and female mating behavior and causes acyclicity in females. The suppressive effects on ovarian cyclicity are mimicked by a mitogenic agent purified from the ground corncob bedding material (corn mitogen; CM), which stimulates the proliferation of estrogen receptor (ER)-positive (MCF-7 cells) and ER-negative (MDA-MD-231 cells) breast cancer cells. Purified CM does not compete for [(3)H]estradiol binding to ER or nuclear type II sites, and its effects on MCF-7 breast cancer cell proliferation are not blocked by the antiestrogen ICI-182,780.