TY - JOUR
T1 - Properties of recombinant human N1-acetylpolyamine oxidase (hPAO)
T2 - Potential role in determining drug sensitivity
AU - Wang, Yanlin
AU - Hacker, Amy
AU - Murray-Stewart, Tracy
AU - Frydman, Benjamin
AU - Valasinas, Aldonia
AU - Fraser, Alison V.
AU - Woster, Patrick M.
AU - Casero, Robert A.
N1 - Funding Information:
Acknowledgements This research was supported by National Institutes of Health grants CA51085, CA85509, CA88843, and CA98454.
PY - 2005/7
Y1 - 2005/7
N2 - The recent cloning of the mammalian gene coding for N1- acetylpolyamine oxidase (PAO) provides the opportunity to directly examine the role of human PAO (hPAO) in polyamine homeostasis as well as its potential role in determining cellular response to antitumor polyamine analogues. To facilitate the study of this enzyme, the production, purification, and characterization of the recombinant hPAO is reported. hPAO oxidizes N1-acetylspermidine (Km=2.1 μM, Kcat=15.0 s-1) and has very high affinity for N1-acetylspermine (Km=0.85 μM, K cat=31.7 s-1). The recombinant hPAO does not efficiently oxidize spermine, thereby demonstrating a significant difference in substrate specificity from the previously described human spermine oxidase PAOh1/SMO. Importantly, hPAO demonstrates the ability to oxidize a subset of antitumor polyamine analogues, suggesting that this oxidase activity could have a significant effect on determining tumor sensitivity to these or similar agents. Transfection of A549 human lung cancer cells with an hPAO-expressing plasmid leads to a profound decrease in sensitivity to those analogues which act as substrates, confirming its potential to alter drug response. One similarity that hPAO shares with human PAOh1/SMO, is that certain oligoamine analogues are potent inhibitors of its oxidase activity. The results of these studies demonstrate how changes in polyamine catabolism may affect drug response.
AB - The recent cloning of the mammalian gene coding for N1- acetylpolyamine oxidase (PAO) provides the opportunity to directly examine the role of human PAO (hPAO) in polyamine homeostasis as well as its potential role in determining cellular response to antitumor polyamine analogues. To facilitate the study of this enzyme, the production, purification, and characterization of the recombinant hPAO is reported. hPAO oxidizes N1-acetylspermidine (Km=2.1 μM, Kcat=15.0 s-1) and has very high affinity for N1-acetylspermine (Km=0.85 μM, K cat=31.7 s-1). The recombinant hPAO does not efficiently oxidize spermine, thereby demonstrating a significant difference in substrate specificity from the previously described human spermine oxidase PAOh1/SMO. Importantly, hPAO demonstrates the ability to oxidize a subset of antitumor polyamine analogues, suggesting that this oxidase activity could have a significant effect on determining tumor sensitivity to these or similar agents. Transfection of A549 human lung cancer cells with an hPAO-expressing plasmid leads to a profound decrease in sensitivity to those analogues which act as substrates, confirming its potential to alter drug response. One similarity that hPAO shares with human PAOh1/SMO, is that certain oligoamine analogues are potent inhibitors of its oxidase activity. The results of these studies demonstrate how changes in polyamine catabolism may affect drug response.
KW - FAD-dependent
KW - HO
KW - Polyamines
KW - Spermidine/spermine N-acetyltransferase
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U2 - 10.1007/s00280-004-0936-5
DO - 10.1007/s00280-004-0936-5
M3 - Article
C2 - 15791459
AN - SCOPUS:21244483811
SN - 0344-5704
VL - 56
SP - 83
EP - 90
JO - Cancer Chemotherapy and Pharmacology
JF - Cancer Chemotherapy and Pharmacology
IS - 1
ER -