Fig. 2.

Growth of Gli1-silenced breast cancer cells. a Gli1 expression was reduced by lentiviral transduction of shRNA directed to Gli1 (sh1, sh2). A non-targeting (NT) shRNA was a control. QRT was performed to confirm a reduction in Gli1 expression in the ERα-positive MCF7 and MDA-MB-361 (361) cells and the ERα-negative MDA-MB-231 (231) and Hs578T cells. The mean expression and standard deviation are presented. b Gli1 expression was also verified by western blot analysis using a rabbit polyclonal antibody. β-actin is a loading control. F9 cells are a teratocarcinoma cell line with a very high expression of Gli1 and are a positive control. The asterisks mark a non-specific immunoreactive band. The absence of an immunore-active band to β-actin in F9 cells in the blot for Hs578T cells is due to technical issues, but does not interfere in the interpretation of the results. c NT control and Gli1 silenced cells were grown until the NT cells approached confluence, which was 7 days for MCF7 cells, 9 days for MDA-MB-361 cells, and 5 days for both MDA-MB-231 and Hs578T cells. Growth was measured by MTT assay. Data are normalized to the NT control and are the mean and standard error of three experiments performed in triplicate. Significance is indicated by asterisks (P < 0.05)