Figure 6

Knockdown of Sp1 suppressed the sphere formation and the expressions of stem cell markers of NPC cells. (A and B) Knockdown of Sp1 repressed the sphere formation of CNE2 cells. CNE2 cells transfected with either siSp1-1#, siSp1-2# or siNC were grown in tumor sphere medium for 7 days. Colonies were photographed at 200× magnification and were counted at 40× magnification. *** P < 0.001. (C) The effect of Sp1 knockdown on the expressions of stem cell transcription factors. CNE2 and HNE1 cells transfected with siSp1-1#, siSp1-2# or siNC for 72 h were analyzed for the levels of stem cell transcription factors by qRT-PCR. The expression level of the indicated gene was normalized to β-actin. * P < 0.05, ** P < 0.01, *** P < 0.001.