Research Article

Gene Expression Profiling and Pathway Network Analysis Predicts a Novel Antitumor Function for a Botanical-Derived Drug, PG2

Figure 4

The effect of combining PG2 and doxorubicin on cell death in HL-60 cells. (a) The top 80 confidence interactions associated with doxorubicin were obtained from STITCH. Five of these (MDM4, IL-8, PRODH2, BCL2, and BIRC5) are derived from the PG2 signature and interact with doxorubicin (identified with arrows). Associated strength is represented by the thickness of the line. Protein-protein interactions are colored in blue, and chemical-protein interactions are colored in green. (b) Drug-target interactions between anthracyclines and PG2. Among these, daunorubicin and epirubicin are associated with only one interactor. HL-60 cells were treated with different concentrations of PG2 for 6 hr. (c) IL8, (d) MDM4, and (e) BIRC5 gene expressions were measured by Q-RT-PCR and normalized to β-actin (). (f) HL-60 cells were treated with various concentrations of PG2 in the presence or absence of doxorubicin (0.75 µg/mL). Cell viability was determined by the trypan blue exclusion assay. Data are expressed as the mean ± standard deviation (SD) of three repeats. A representative result from three independent experiments is shown () (; ; versus vehicle control group).