Fig. 2.

Sp1 is upregulated in GBM and enriched in TMZ-resistant cells. (A) A database study from Sun et al. in ONCOMINE (www.oncomine.org) showed significantly increased Sp1 mRNA expression in GBM [40]. (B) Sp1 protein expression in samples from brain tumor tissue array blocks was analyzed by IHC. The correlation between Sp1 level and tumor grade is shown in the right panel. (C) The expression of Sp1 in five TMZ-resistant GBM lines (TMZ-R) and their parental (Con) cells was measured by Western blotting. Quantitation of Sp1 levels in control and TMZ-resistant U87MG cells is shown in the right panel. (t-test: ***p < 0.001).