Current location: JICS Archive > Vol. 6 > No. 4 > Articles : 6

Interference of Arsenic Trioxide on Magnesium Dependent Polymerization of Microtubule Proteins

R. Mahinpour^a, G.H. Riazi^a,*, M.N. Sarbolouki^a, A.A. Moosavi-Movahedi^a, S. Ahmadian^a, M.A. Shokrgozar^b and S.Z.  Moosavi-Nejad^c

^aInstitute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
^bNational Cell Bank of Iran, Pasteur Institute of Iran, Tehran, Iran
^cDepartment of Biology, Faculty of Science, Alzahra University, Tehran, Iran

Prevention of microtubule polymerization is considered as one of the promising approaches towards inhibition of cell proliferation, especially in treatment of malignancies. Arsenic trioxide, As₂O₃, is being successfully used in the treatment of human lymphoma, while the mechanism of its therapeutic function is still under investigation. Experiments were designed to determine if indeed As₂O₃ interferes with polymerization of nanotube microtubule. Microtubules were extracted from sheep brain and their interaction with arsenic trioxide was examined by spectrometery. Electrical conductometry of 2 mM MgSO₄ solution containing various concentrations of As₂O₃ was studied in order to determine their possible interaction. Transmission electron microscopy was used to show microtubule structure in the presence of arsenic trioxide. Fluorometric characteristics of tubulin dimer were examined in presence of varying concentrations of arsenic trioxide. It is concluded that arsenic trioxide interacts with Mg²⁺ ion around GTPase site of β-tubulin, resulting enhancement of depolymerization of the microtubule polymer.

Keywords: Microtubule polymerization, Arsenic trioxide, Anticancer drug, Magnesium ion