In contrast, the expression of a key marker in the apoptotic pathway, caspase-3, is largely unaffected by these treatments. Figure 4 Rapamycin and docetaxel decrease the level of Survivin expression while the expression of caspase-3 is unaffected. (A) The presence of Mdivi1 cost various proteins was detected by Western blot. (B) The relative level of Survivin and caspase-3 expression to GAPDH is shown in bar graph. Combination treatment of rapamycin with docetaxel decreases the phosphorylation level of ERK1/2 in 95D

cell lines To further clarify the cell growth inhibitory mechanism of rapamycin with docetaxel, we examined the changes in the expression levels of the enzymes involved S63845 in cell growth signal transduction pathways. 95D cells were exposed to rapamycin (10 nM, 20 nM) and docetaxel (1 nM, 10 nM) alone or in combination

(Rapa 20 nM+ DTX 10 nM). After 24 hr of incubation, the expression and the phosphorylation levels of ERK1/2 were examined. As presented in Figure 5, a 24-hr exposure to rapamycin or docetaxel alone did not significantly alter the level of expression or phosphorylation of ERK1/2, whereas cells treated with the combination of rapamycin with docetaxel exhibited a marked reduction in the phosphorylation levels of ERK1/2. This suggests that there may exist positive interactions between rapamycin and docetaxel in the suppression of ERK1/2 pathway in 95D cells. Figure 5 Combination treatment of rapamycin and docetaxel PCI-34051 cost decreases phosphorylation of ERK in 95D cell lines. 95D cells were treated with 1 nM and 10 nM docetaxel alone, 10 nM and 20 nM rapamycin alone and a combination with 10 nM docetaxel and 20 nM rapamycin for 24 hr. After incubation, levels of ERK1/2 and p-ERK1/2 (phosphorylated Tyr204) were examined. Con: control, Rapa: rapamycin, DTX: docetaxel. Discussion The prognosis for inoperable or recurrent lung cancer patients

has not been much improved despite the advent of new chemotherapeutic agents. the Although early stage lung cancer is potentially curable, most lung cancer patients were already at advanced stages when diagnosed. Moreover, most advanced lung cancer patients have a history of smoking thus suffer concurrent complications in both cardiovascular and pulmonary systems, rendering aggressive surgery and multimodality therapy unfeasible. Docetaxel is a common second-line therapeutic agent used for advanced NSCLC. In several randomized clinical tries, combination cytotoxic chemotherapy regimens for second-line therapy of advanced NSCLC failed to establish patient survival benefit, although there was report of higher cytotoxic effect[23]. It has been thought that the clinical benefit of present second-line therapies for advanced NSCLC has reached its peak.