Antimicrotubule drugs

Yamamoto, E., Zeng, L., and Baird, W. V. (1998). Alpha-tubulin missense mutations correlate with antimicrotubule drug resistance in Eleusine indica. Plant Cell 10, 297-308. 

The formation of the neurite-like processes appears to be dependent on assembly of microtubules as colchicine and Colcemid, antimicrotubule drugs, prevented shape changes in the presence of butyrate (2,8). The amount of tubulin per cell did not change when HeLa were treated with butyrate (R.C.Henneberry, unpublished observations). The role of microtubule assembly was further explored with a calcium ionophore which alters intracellular calcium levels and thus promotes microtubule depolymerization. 

Stearns, T., M. A. Hoyt, and D. Botstein (1990). Yeast mutants sensitive to antimicrotubule drugs define three genes that affect microtubule function. Genetics 124, 251-262. 

The antimitotic mechanism of taxol differs from the antimicrotubule agents such as colchicine and the vinca alkaloids discussed earlier. Rather than causing disassembly of the microtubules, taxol actually enhances tubulin polymerization. This upsets the normal dynamic equilibrium between soluble tubules, which are dimers, and the microtubule polymers. The stabilization of the latter inhibits mitosis in the latter part of Phase G2 and M. Although sharing much of the toxicology of many of the anticancer drugs, taxol promises to be an important addition to the cancer armamentarium. 

The overexpression of the anti-apoptotic protein Bcl-2 in cancer has been associated with resistance to chemotherapeutic agents. The phosphorylation of Bcl-2 is one mechanism by which antimicrotubule agents in clinic such as paclitaxel, taxotere and vinblastine inactivate the Bcl-2 proteins. Many natural products and semi-synthetic molecules are used in clinic for anticancer activity. In this chapter, the importance of the Bcl-2 phosphoiylating molecule from nutraceuticals that shed light on the future development of molecules for chemoprevention and anticancer drugs will be discussed. The roots of Licorice (Glycyrrhiza glabra) have been used in traditional medicine for a variety of... 

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