The unchanged FLT uptake late in the treatment course could be due to several factors

of proliferation induced by the NHAPI-TMX combination was more pronounced than the effects of either of the individual agents alone. Moreover, different shapes of the proliferation curves of NHAPI, the NHAPI-Fe complex and their combinations with TMX were observed. The proliferation curve of NHAPI at its IC50 concentration closely paralleled the control curve, which may be caused by an increase in cells in the S-phase of the cell cycle that have a broader adhesive area. The shape of the proliferation curve of cells exposed to NHAPI at double its IC50 concentration consisted of an initial increase of adhesivity, followed later by decline in cellular viability. 4.2. Flow cytometric analysis. Flow cytometric analyses revealed a slight, but significant increase in the proportion of S-phase cells after a 72 h incubation with NHAPI. This observation is supported by the observed shape of the electrical impedance proliferation curve of the NHAPI-treated cells, as described above. Furthermore, a significant decrease in G2/M-phase cells was observed following the incubation of the cells with the 26 IC50 concentration of NHAPI relative to the control. TMX at the tested concentration showed a significantly decreased S-phase population in favor of G1 cells. Increasing the concentration of TMX resulted in excessive toxicity that precluded cell cycle analysis. In contrast to the ligand alone, the NHAPI-Fe complex caused no significant changes in the cell cycle. The combinations of NHAPI or its Fe complex with TMX resulted in a G1-S cell cycle arrest that was similar to that observed with TMX treatment alone. 4.3. Mitochondrial membrane potential. To examine the qualitative and quantitative assessment of the mitochondrial membrane potential, epiLuteolin 7-O-β-D-glucoside cost fluorescence microscopy and flow cytometry were PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19638617 used implementing the JC-1 PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19640586 probe. Epifluorescence microscopy to assess DYm: Incubation of control cells with the JC-1 probe exhibited marked red fluorescence which reflects the mitochondrial inner membrane potential -dependent accumulation of probe dimers in actively respiring mitochondria. Diffuse cytosolic green fluorescence indicates monomers of the probe released into the cytoplasm after mitochondrial depolarization, whereas yellow fluorescence indicates a mixture of red and green fluorescence in cells undergoing mitochondrial depolarization. A lack of fluorescence is indicative of probe release from necrotic or secondary apoptotic cells. In cells incubated with TMX in particular, but also NHAPI and to a much lesser extent NHAPI-Fe, there was diffuse green and rarely yellow fluorescence in some cells, but not others. Combined incubations of NHAPI or the NHAPI-Fe complex with TMX resulted in a marked decrease in total fluorescence, which was primarily due to a loss of red fluorescence. In the small percentage of cells remaining after treatment with the combination of agents, green and sometimes yellow fluorescence was observed, with only an extremely minor indication of red fluorescence in the NHAPI+TMX combination. Collectively, these observations from the combination studies are indicative of probe loss from necrotic or late-stage apoptotic cells due to organelle and membrane damage. With respect to cellular morphology as shown by bright field microscopy, the cells that were incubated with TMX alone tended to retract their filopodia and “round up”, whereas NHAPI slightly increased their surface area compared to the control cells. Combinations of NHAPI or its