Del1-shRNA downregulates Del1 expression but has no effects on cell viability in vitro. (A) Del1 protein (upper row) in lysates of untreated LS-174T cells (lane 1) or cells transfected with control vector (lane 2), or Del1-shRNA plasmid (lane 3) was Western blotted. The density of each band was measured and compared to that of the internal control β-actin (lower row). (B) Del1 mRNA (350 bp) expression detected by RT-PCR in lysates of untreated LS-174T cells (lane 2) or cells transfected with control vector (lane 3), or Del1-shRNA plasmid (lane 4). G3PDH (500 bp) was amplified as a PCR internal control. Lane 1 denotes the DNA marker. * Indicates a significant difference at P < 0.05 in the band intensities of Del1 compared to control. (C) The LS-174T cells were further cultured in medium supplemented with %FCS, or (D) without FCS, and harvested at indicated time points. The viability of cells was assessed by the MTT method.