Figure 4

Gene transfection of STAT1C upregulated apoptosis and induced sub-G ₁ cell cycle increase. By western blots, gene transfection of STAT1C into ESCC cell lines induced cleavages of caspase 3, downregulated several pro-apoptotic proteins (including BCL-2, BCL-xL, survivin), and promoted G₁ cell-cycle arrest by decreasing cyclin D1 and increasing p21^waf1. Cell lysates were collected 2 days after the gene transfection of STAT1C in EC1 and EC109 (A). Time course experiments were performed, and the decrease in cyclin D1 expression was detectable as early as 6 hours after STAT1C transfection in EC1 cells (B). (C) Cell cycle analysis using flow cytometry revealed that STAT1C induced a significant increase in the sub-G1 fraction in both cell lines, EC1 and EC109 (*p < 0.05). All experiments were performed in triplicate, and results from a representative run are shown. (E.V.: empty vector).