{Reference Type}: Journal Article {Title}: Effects of antibiotic antitumor drugs on nucleotide levels in cultured tumor cells: an exploratory method to distinguish the mechanisms of antitumor drug action based on targeted metabolomics. {Author}: Wang F;Liu X;Liu C;Liu Z;Sun L; {Journal}: Acta Pharm Sin B {Volume}: 5 {Issue}: 3 {Year}: May 2015 {Factor}: 14.903 {DOI}: 10.1016/j.apsb.2015.03.010 {Abstract}: Nucleotide pools in mammalian cells change due to the influence of antitumor drugs, which may help in evaluating the drug effect and understanding the mechanism of drug action. In this study, an ion-pair RP-HPLC method was used for a simple, sensitive and simultaneous determination of the levels of 12 nucleotides in mammalian cells treated with antibiotic antitumor drugs (daunorubicin, epirubicin and dactinomycin D). Through the use of this targeted metabolomics approach to find potential biomarkers, UTP and ATP were verified to be the most appropriate biomarkers. Moreover, a holistic statistical approach was put forward to develop a model which could distinguish 4 categories of drugs with different mechanisms of action. This model can be further validated by evaluating drugs with different mechanisms of action. This targeted metabolomics study may provide a novel approach to predict the mechanism of action of antitumor drugs.