Inpharma 1652 - 23 Aug 2008

Novel way around drug resistancediscovered by researchers

Researchers from Stanford University, Palo Alto,California, US, have discovered a way of overcomingpaclitaxel [Taxol] resistance in ovarian cancer cells, andtheir approach may be applicable for the treatment ofother diseases for which drug resistance is an issue.

The key to their discovery is arginine, an amino acidpresent in almost every cell in the body. Professor PaulWender stated that "nature has developed all this firepower for getting things into cells, and one of the ways isto create entities that are arginine-rich". The researchersfound that the guanidinium subunit of arginine enablesforeign substances entry into cells. Further researchrevealed that if mice with paclitaxel-resistant ovariancancer were treated with paclitaxel attached to a’necklace’ of eight arginine molecules, the efficacy of thedrug was restored.

Their approach circumvents the type of resistancewhich develops as the pumps in the cell membranebecome sensitised to foreign substances. These pumps,which eject foreign material from the cell, increase innumber in resistant cells; unfortunately, the foreignsubstances they eject can include therapeutic agents.However, by bonding drugs to arginine transporters thedrugs can enter the cells without attracting the notice ofthe pumps.

Professor Nelson Teng, said "this could potentially beused with any drug which is effective but has a deliveryproblem", including drug-resistant infections and othercancers.Eurekalert. New method to overcome multiple drug resistant diseases developed byStanford researchers. Media Release : 18 Aug 2008. Available from: URL: http://www.eurekalert.org 809092337

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Inpharma 23 Aug 2008 No. 16521173-8324/10/1652-0001/$14.95 Adis © 2010 Springer International Publishing AG. All rights reserved