05, **P …IC50 value for deracoxib was found as 974.481��M. However, as a maximal inhibitory effect of piroxicam was not observed in the Ceritinib mw concentration range studied, the corresponding IC50 value could not be calculated. When the 2 inhibitors were combined, a significant decrease in cell growth was observed at 100, 250, 500, and 1000��M concentrations (36.5%, 34.94%, 43.84%, and 50.66%, resp.) (Figure 2). The combination of both COX inhibitors exhibited a synergistic effect in CMT-U27 cells. Figure 2Antiproliferative effects of coadministration of piroxicam (Pir) and deracoxib (Der) on canine mammary carcinoma cell line after 72h incubation. Data are expressed as the percentage of inhibition compared with control in which cell survival was …3.2.

Apoptosis AssayThe apoptotic cell number of CMT-U27 cells after 72h incubation in the presence or absence of piroxicam and deracoxib at various concentrations (50�C1000��M) was shown in Figure 3. Piroxicam at 1000��M concentration (P < 0.05), deracoxib at 250��M, and higher concentrations (P < 0.01, P < 0.001) decreased the number of viable cells and increased the number of apoptotic cells as a sum of early and late apoptotic cells significantly.Figure 3 Flow cytometric analysis of apoptosis of CMT-U27 cells after treatment with piroxicam (Pir) and deracoxib (Der) for 72h. Data are expressed as mean values �� standard error of means shown with *P < 0.05, **P < 0.01, ...Whereas, again, the combination of piroxicam and deracoxib (100��M and higher) exhibited a significant increase in the apoptotic activity.

The percentages of apoptotic cells were 5.56% (control), and 5.32% (piroxicam 50��M + deracoxib 50��M), 23.47% (piroxicam 100��M + deracoxib 100��M), 24.14% (piroxicam 250��M + deracoxib 250��M), 28.86% (piroxicam 500��M + deracoxib 500��M), 53.62% (piroxicam 1000��M + deracoxib 1000��M). Figure 4 shows representative results of flow cytometry for the apoptosis of CMT-U27 cells after incubation in the presence of piroxicam and deracoxib.Figure 4Flow cytometric analysis of apoptosis of coadministration of piroxicam and deracoxib on canine mammary carcinoma cell line after 72h incubation. The lower left quadrant of the histogram shows the viable cells, which exclude PI, and are negative …3.3.

Cell Cycle AnalysesCell cycle phase distribution was evaluated to assess which cell cycle changes contribute Drug_discovery to CMT-U27 cell number reduction by piroxicam and deracoxib, and cellular DNA contents were examined by flow cytometry. The results showed that treating cells with piroxicam and deracoxib at 500 and 1000��M concentrations caused a significant inhibition of cell cycle progression in CMT-U27 cells at 72h (Table 1) resulting in a clear increase of the percentage of cells in the G0/G1 phase when compared with the control. The cell cycle evaluation in CMT-U27 cell line showed an average: 45.23%, 35.62%, and 19.16% of cells in G0/G1, S, and G2/M phases, respectively.