Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2006-8-21
pubmed:abstractText
The oxazaphosphorines including cyclophosphamide (CPA), ifosfamide (IFO) and trofosfamide are one important group of alkylating agents. However, resistance is the major hindrance for success of oxazaphosphorine chemotherapy. The mechanism of resistance to oxazaphosphorines is not fully identified, but recently some novel insights into these aspects have been generated by using sensitive analytical techniques and powerful pharmacogenetic techniques. Potential mechanisms for oxazaphosphorine resistance include decreased activation by cytochrome P450s (e.g. CYP3A4, CYP2C9 and CYP2B6), increased deactivation of the agents by deactivating enzymes such as aldehyde dehydrogenases (ALDHs), increased cellular thiol level, increased DNA repair capacity, and altered cellular apoptotic response to DNA repair, e.g. deficient apoptosis due to lack of cellular mechanisms to result in cell death following DNA damage. In addition, decreased cellular accumulation of cytotoxic species of oxazaphosphorines may also play a role in the resistance. This review highlights the pharmacology of oxazaphosphorine anticancer drugs and possible agents that reverse the resistance to these agents. Possible agents that can overcome oxazaphosphorine resistance include inducers of CYPs, modulators of GSTs and ALDHs, modulators of DNA repair process, antisense oligonucleotides against genes encoding various enzymes and signalling proteins, and novel gene delivery systems. Most of these agents have been investigated in preclinical studies and promising results have been observed. To date, several types of these agents are being evaluated in Phase III trials in cancer patients. Further studies are needed to identify the molecular targets associated with resistance to oxazaphosphorines.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1568-0096
pubmed:author
pubmed:issnType
Print
pubmed:volume
6
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
385-407
pubmed:dateRevised
2008-9-9
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Reversal of resistance to oxazaphosphorines.
pubmed:affiliation
Department of Pharmacology, Faculty of Medicine, National University of Singapore.
pubmed:publicationType
Journal Article, Review, Research Support, Non-U.S. Gov't