Stably downregulated ENO1 expression suppressed cell proliferation in vitro and tumorigenicity in vivo. (A). Effect of ENO1 knockdown on U251 and U87 cell proliferation as measured by MTT assay. Absorbance was read at 490 nm with averages from triplicate wells. Data are presented as mean ± SD for three independent experiments. (B). Transiently reducing the expression of ENO1 by siRNA inhibited cell proliferation in glioma U251 and U87 cells. (C). In vitro proliferative ability of glioma cells was significantly decreased in ENO1-suppressed cells compared to PLV-Ctr cells by colony formation assay. (D). When compared with PLV-Ctr, tumorigenicity of shENO1-U25 and shENO1-U87 cells was markedly reduced in vivo (*P < 0.05). (E). Immunohistochemical (IHC) staining of ENO1 expression in subcutaneous tumors of mice injected with shENO1 and PLV-Ctr cells.