Fig. 1The ectopic expression of maspin decreases the rate of survival to drug-induced cell death. (A) RT-PCR and Western blot analysis demonstrating the ectopic expression of recombinant maspin in the NCI-H157 cells. (B) The effect of a stable maspin expression on the cytotoxicity of cisplain (50 µM), doxorubicin (5 µM) and etoposide (10 µM) in the NCI-H157 cells. Cells (1×105/well) were plated in 6-well plates and they were treated with drugs for 24 h on the following day. Trypan blue staining was performed to detect the live cells and cell survival is expressed as the ratio of the number of viable cells following a given treatment to the number of untreated cells×100 (%). Bars, SD.
Fig. 2Maspin knockdown modulates the phosphorylation of Akt and drug-induced apoptosis. (A) Active caspase-3 and PARP cleavage demonstrates reduction of active caspase-3 and the cleaved PARP fragment in the siMaspin-transfected (siMas, 50 nM) A549 cells, as compared with the parental (-), and siControl-transfected cells (siC, 50 µM), after the treatment with 5 µM doxorubicin. The identical blot was reprobed with β-actin as a control for loading. (B) Western blot analysis demonstrating the induction of phosphorylated Akt in the siMaspin (50 nM) - transfected A549 cells after EGF (10 nM) treatment.
Fig. 3Western blot analysis of the survival-related proteins in the total cell lysates from the tumors derived from the mock-transfected (H157/C, 5 samples) and maspin over-expressing (H157/mas, 4 samples) cells. The identical blot was reprobed with β-actin as a control for loading.
Fig. 4The effect of maspin DNA transfer on the established tumor. A pCMV-maspin or control plasmid was given every other day (arrow) into the subcutaneous tumor that had been established after the injection of NCI-H157 cells (5×106 cells). The plasmid was administered as a mixture of 50 µg DNA in 50 µL PBS per injection. Nine mice were used for each group. p=0.0048, t-test comparing the control plasmid injected xenographs to the pCMV-maspin injected xenografts on day 23. Bars, SEM.
Table 1List of the genes that were up- or down-regulated by maspin