In the JY 1 106 treatment of A549 cells, the cytotoxic response to Taxol increased dramatically. Isobologram analysis was adopted to study the potential synergism selleck screening library of cellular toxicity following a combination of Taxol and JY 1 106 treatment. Isobologram analysis as sists in the determination of whether or not combination therapies are additive, synergistic or an tagonistic. The CI values presented in Figure 5B demonstrate that for all doses examined, the combina tions of Taxol and JY 1 106 were synergistic in A549 cells. A similar degree of sensitization was observed in multiple cancer cell lines. Measuring BH3 only protein expression in Taxol treated cancer cells by western blotting indicated that two BH3 only proteins, Bim and PUMA, were significantly increased upon Taxol treat ments, whilst others remain unchanged.

Annexin V/flow cytometric analysis of A549 cells con firmed an increased sensitization with a combination of Taxol and JY 1 106 by revealing that the Inhibitors,Modulators,Libraries percentage of apoptotic cells was significantly higher when cells were treated with both agents compared with individual treat ments. To evaluate whether inhibiting Bcl xL and Mcl 1 could lead to decreased ATP production in metabolically stressed cancer cells, A549 cells were exposed to a very low dose of JY 1 106 in addition to metabolic stress. As demonstrated in Figure 6A, significant cell death was observed in the A549 cells treated with the combination of metabolic stress medium and 0. 25 uM JY 1 106, which has little effect on cancer viability under regular culture conditions.

Decreased ATP production was quan titatively measured in A549 cells. Measuring BH3 only protein expression in cancer cells Inhibitors,Modulators,Libraries after meta bolic stress indicated that Bim and PUMA were signifi cantly increased upon 12 hours of metabolic stress. Annexin V/flow cytometric analysis of A549 cells again confirmed an increased sensitization with a combination of metabolic stress and 1 uM JY 1 106 Inhibitors,Modulators,Libraries by revealing that the percentage of apoptotic cells was signifi cantly higher when cells were treated with both agents compared with individual treatments. Inhibition of tumor growth by JY 1 106 in a lung cancer xenograft model To evaluate the effects of JY 1 106 in an animal model, 10 million A549 cells were injected Inhibitors,Modulators,Libraries intraperitoneally Inhibitors,Modulators,Libraries into nude mice, and the tumors were allowed to grow for 20 days before any treatment was initiated.

Following three daily intraperitoneal administrations of JY 1 106 at 25 mg/ kg or vehicle control, each animal appeared to be in good health. At necropsy, no gross signs of toxicity were found. Intraperitoneally transplanted tumor samples were col lected and stained using the TUNEL assay. As demon strated in Figure 7A, JY more info 1 106, but not the vehicle control, induced significant apoptosis in the tumors. Histopa thologic examination revealed no significant pathologic lesions in the liver, kidney, lung and spleen.