Microtubules are tubulin polymers that form part of the cytoskeleton and provide structure and shape for eukaryotic cells. Importantly, microtubules are one of the cytoskeletal filament systems in eukaryotic cells. Their role is to determine cell shape and various cell movements. Particularly, the microtubule cytoskeleton is involved in the transport of intracellular substances, which is carried out by the moving proteins on the surface of microtubules. Tubulin is a dimer composed of two closely related 55 KD polypeptides, namely α- Tubulin and β- Tubulin. Microtubule polymerization takes place through nucleation elongation mechanism, i.e. reversible noncovalent addition at both ends of microtubule α- And β- Tubulin dimer.

Obviously, anti-microtubule agents prevent cell growth by stopping mitosis (cell division). Anti-microtubule agents are anti-mitotic chemicals from plants, which act on the polymerization kinetics of spindles to prevent cell proliferation. Besides, the common feature of anti-MT drugs is that they specifically bind to TB in the dimer, MT, or some other form. Moreover, even small changes in microtubule dynamics can participate in spindle checkpoint, preventing cell cycle progression during mitosis and subsequently leading to cell death. Furthermore, natural compounds that target microtubules and destroy the normal function of the mitotic spindle are one of the best cancer chemotherapy drugs available in clinic. Today, we will introduce an orally active antimicrotubule chemotherapy agent, Estramustine.

Estramustine, an Estradiol Analog, is an Orally Active Anti-microtubule Chemotherapy Agent.

Firstly, Estramustine, an estradiol analog, is an orally active antimicrotubule chemotherapy agent. Meanwhile, Estramustine depolymerizes microtubules by binding to microtubule-associated proteins (MAPs) and/or to tubulin. Nonetheless, Estramustine induces prostate cancer cells apoptosis and can be used for prostate cancer research.

Secondly, Estramustine with 1 µg/mL treatment suppressed PC3 cell growth. Estramustine significantly elevates phosphatidylserine eversion amount on PC3 cells. Estramustine induces PC3 cell apoptosis and decreases MiR-31 level. Interestingly, Estramustine induces s prostate cancer cell line PC3 apoptosis by reducing miR-31. Additionally, Estramustine is selectively taken up by prostate cells and exerts antineoplastic effects by interfering with microtubule of dynamics and by reducing plasma levels of testosterone.
Again, Estrone and estradiol are products of the metabolism of Estramustine. They have shown antigonadotrophic activity resulting in reduced testosterone levels similar to those achieved after surgical castration. In addition, Estramustine with 4-12 mg/kg/day by IP for 2 weeks inhibits PAC120 tumor growth by 53% by day 35.

Finally, Estramustine, an estradiol analog, is an orally active antimicrotubule chemotherapy agent.


Perry CM, et al. Drugs Aging. 1995 Jul;7(1):49-74.