Figure 4. Downregulation of Gli1/2 leads to decreased cell viability and downregulation of Gli2, but not Gli1, sensitizes ovarian cancer cells to cisplatin in vitro.
A) mRNA expression of GLI1 and GLI2 was quantified in 8 different ovarian cancer cell lines using quantitative PCR. Gene expression is shown as log2 transformed ΔC T values. B) Downregulation of Gli1/2 in A2780cp20 and ES2 cells using 2 different siRNA constructs was determined by quantitative PCR. Each siRNA construct demonstrated selectivity for the GLI gene to which it was designed against. ND = not detectable; *P<0.01. C) Knockdown of Gli1 or Gli2 alone diminished A2780cp20 cell viability, whereas only knockdown of Gli2 diminished ES2 cell viability as determined by MTT assay. Increased sensitivity to cisplatin (CDDP) was noted in A2780cp20 and ES2 cells transfected with GLI2 siRNAs, but not GLI1 siRNAs. D) Cell cycle analysis (PI staining) of A2780cp20 cells exposed to control siRNA, GLI1 siRNA or GLI2 siRNA for a total of 72 hours. Downregulation of Gli2, and to a lesser extent Gli1, led to an accumulation of cells in the sub-G0 or apoptotic fraction. Data are representative of 3 independent experiments.