The effect and mechanism of the ciglitazone on lung cancer cells A549 growthin vitro andin vivo were studied. Various concentrations of ciglitazone were added to the cultured A549 line, and the proliferation and differentiation of A549 cells were examined by MTT and cytometry analysis. A549 cells (1×10⁶/mouse) were inoculated subcutaneously into 20 nude mice, which were randomly divided into two groups: the control group, the ciglitazone treated group. The weights of subcutaneous tumors were measured. The expression of cyclin D1 and P21 in the lung was detected by immohistochemistry and Western blot respectively. The results showed that the proliferation of A549 was inhibited significantly by ciglitazone in a dose- and time-dependent manner. There were more cells arrested in G₁/G₀ phase and the expression of PPARγ was markedly up-regulated in ciglitazone-treated group. Direct injection of ciglitazone into A549-induced tumors could suppress tumor growth in nude mice and the growth inhibitory rate was 36%. The expression of cyclin D1 was decreased and P21 increased significantly in ciglitazone-treated group as compared with control group. It was concluded that ciglitazone could inhibit A549 proliferation dose-dependently and time-dependently and induce differentiation, which might be related to the modulation of cell cycle interfered by PPARγ.

In order to establish state high expression cell lines, the eukaryotic expression vector pIRES2EGFP and recombinant plasmid pIRES2EGFP-TIM-3 were transfected into mammalian cells CHO by Lipofectamine. The transfected cells were cultivated under selective growth medium including G418 and green fluorescent protein (GFP) positive cells were sorted by FACS. Simultaneously, growing transfectants were selected only by G418 in the medium. The GFP expression in stably transfected cells was detected by FACS. Under selective growth conditions with G418, the percent-age of GFP positive cells was reduced rapidly and GFP induction was low. In contrast, the percent-ages of GFP positive cells were increased gradually after FACS. By 3 rounds of GFP selection, the stable high expression cell lines were established. Furthermore, using FACS analysis GFP and the target protein TIM-3 co-expression in the stable transfectants cultured in nonselective medium was detected. Theses results demonstrated that the stably transfected cell lines that express high titer of recombinant protein can be simply and fleetly obtained by using GFP and selective growth medium.