Figure 1

Characterization of doxorubicin treatment of tumor cells. MOSEC or MOSEC/luc tumor cells (1 × 10⁶) were cultured in the presence of different doses of doxorubicin: 0, 0.01, 0.1, 1,10, 50, 100 μg/ml. Flow cytometry was performed on doxorubicin-treated MOSEC cells (MOSEC-dox) at 2 hrs of incubation. (A) Flow cytometry showing uptake of doxorubicin at each concentration by the MOSEC tumor cells. Another pool of MOSEC cells incubated for 2 hrs with doxorubicin were spun to form cell-pellets, which were lysed with protein-extraction buffer and added to DMSO. The amount of doxorubicin in the cell lysate solution was determined using spectrophotometry along with generating a standard curve. (B) Bar graph superimposed under standard curve showing the amount of doxorubicin inside the MOSEC cells for each concentration after extraction from cell lysates. The numbers above each bar indicate μg of doxorubicin per 1 × 10⁶ cells. The left y-axis indicates optical density reading at 470 nm; the right y-axis indicates micrograms of doxorubicin used to generate the standard curve. A pool of MOSEC tumor cells was incubated with doxorubicin for 24 hrs and an MTT assay was then performed. (C) Representative bar graph from the MTT data showing the viability of MOSEC cells after incubation with different concentrations of doxorubicin. MOSEC/luc tumor cells which were incubated with doxorubicin for 24 hrs were imaged using bioluminescence IVIS systems. (D) Luminescence image showing luciferase activity in viable MOSEC/luc cells. The numbers at the top indicate 3 identical trials of the same experiment. The bar graph depicts the kinetic expression of luciferase in MOSEC/luc cells incubated with different amounts of doxorubicin.