6 >0.05 79 84.0 learn more >0.05 female 26 14 53.8   19 73.1   age               ≤60 67 41 61.2 >0.05 52 77.6

>0.05 >60 53 29 54.7   46 86.8   degree of differentiation               high 45 19 42.2 <0.01 31 68.9 <0.01 moderate 46 29 63.0   39 84.8   low or undifferentiation 29 22 75.9   28 96.6   clinical stage               I~II 43 18 41.9 <0.01 29 72.1 <0.01 III 77 52 67.5   69 87.0   lymph nodes metastasis               yes 73 49 67.1 <0.01 66 90.4 <0.01 no 47 21 44.7   32 68.1   Survivin Positive** 98 63 90(63/70)       = 0.005 Note: ** : r s = 0.255, p = 0.005. Figure 1 Expression of survivin and HIF-1α in NSCLC and benign lung disease tissues. Survivin and HIF-lα protein were detected and localised within paraffin-embedded Dasatinib human lung tissue using immunohistochemistry. A and B represent

the negative expression of survivin protein and HIF-1α protein, respectively, in benign lung disease tissues. C and D represent the positive expression (arrow) of survivin protein and HIF-1α protein, respectively, in NSCLC,. E: The graph shows the statistical results. 81.60% (98/120) of lung cancer tissue samples were positive for survivin staining, and 58.33% (70/120_) of lung cancer tissue samples were positive for HIF-1α staining. ** p < 0.01. Hypoxia induces expression of HIF-1α and survivin When A549 cells were incubated in hypoxic conditions for 24 h, the expression of HIF-1α Casein kinase 1 (2B, C, D) and survivin (2A, C, D) were detected by quantitative real time, reverse transcription-PCR (2A, B) and western blot (2 C, D). As shown in Fig 2, the expression of survivin and HIF-1α was increased significantly in hypoxia as compared to normoxia (p < 0.01). Figure 2 Hypoxia induces expression of HIF-1α and survivin. A549 cells were cultured in 10% FBS medium under hypoxic or normoxic conditions for 24h. The relative levels of survivin (A) and HIF-1α (B) to GAPDH mRNA were determined by quantitative

real time, reverse transcription-PCR. C: The expression of survivin and HIF-1α protein in A549 cells following HIF-1α-siRNA treatment as detected by Western blot analysis. D: The graph shows the statistical results of relative expression level of survivin and HIF-1α to β-actin protein. Data are given as means ± SD, n = 3, ** p < 0.01. Site directed mutagenesis of HIF-1α binding site on the survivin promoter decreases transcription activity of the survivin promoter To determine whether the binding-site of HIF-lα can affect the transcription of survivin in A549 cells, the GTGC sequence in -19 ~ -16 bp of survivin promoter (Fig. 2A) was changed to AGC by site-directed mutagenesis, and the relative activity of the normal and mutated survivin promoter were detected by luciferase activity assay. As shown in Fig.