Effects of estrogens on microtubule polymerization in vitro: correlation with estrogenicity.

Several estrogens of diverse classes, namely stilbene estrogens, steroidal estrogens, phytoestrogens, mycoestrogens, lignans, and bisphenol A, were studied for their ability to interfere with the assembly of microtubules under cell-free conditions. Inhibition of microtubules in intact cells may lead to the induction of micronuclei and aneuploidy and thereby contribute to estrogen-mediated carcinogenesis. Diethylstilbestrol and various other stilbene estrogens, as well as bisphenol A, were good inhibitors of microtubule polymerization whereas the other tested compounds were devoid of this activity. Therefore, the ability of estrogenic substances to interact with microtubules does not correlate with the hormonal activity.