Figure 9.

Apoptosis induced by SPHK1 depletion in HCC38 parental and CSCs is dependent on STAT1 function. (A) A stable pool of STAT1 depleted cells was generated by transduction of lentiviral shRNA targeting STAT1, followed by brief puromycin selection. Cells were then transfected with SPHK1 shRNAs. Immunoblots were performed at 72 h after SPHK1 knockdown. (B) Depletion of STAT1 rescued SPHK1 knockdown induced apoptosis. Apoptosis was quantitated using Annexin V/7-AAD flow cytometry at 72 h after SPHK1 knockdown. Bars represent the means ± s.d. of three independent experiments. Asterisks (*) indicate statistical significance compared with non-silencing (NS) control cells (p < 0.01, Student’s t-test).