Figure 1.

Knockdown of Srx sensitizes human lung cancer A549 cells to ER stress–induced cell death. A, representative results of Srx knockdown using two different shSrx constructs in human lung cancer cells. B, knockdown of Srx sensitizes cells to tunicamycin-induced death. Data from six replicates are presented as mean ± S.D. (error bars), and the IC₅₀ values were calculated through log transformation and linear regression analysis. Calculated IC₅₀ values of control cells (ShNT) and Srx knockdown cells (ShSrx) are 1.69 and 0.36 μg/ml, respectively. C, knockdown of Srx induces a rapid response of UPR, as indicated by the accelerated splicing of XBP-1 mRNA. D, expression of spliced XBP protein and activation of ATF6α in the presence of tunicamycin in A549 control and Srx knockdown cells. NS, nonspecific band. The bar graph with a dot plot on the right indicates the quantitative results (*, p < 0.05, t test).