Figure 3.

PALMD induces apoptosis in response to DNA damage. (a) The specificity of the siRNAs of PALMD. Three different siRNAs, siPALMD-1, siPALMD-2, and siPALMD-3 or non-silencing siRNA were transfected into U2OS cells. After 24 h incubation, cells were harvested and total RNA was isolated. mRNA (upper panel, data represent fold expression of PALMD relative to the non-silencing siRNA) and protein expression (lower panel) were examined. (b) Apoptotic assay in PALMD-depleted cells. U2OS cells were seeded into four-well chamber slides and transfected with non-silencing siRNA, siPALMD-1, siPALMD-3, or sip53. Cells were treated with ADR or left untreated and incubated for 24 h. The results represent the percentage of the TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling)-positive cells. *P<0.01. (c) Apoptotic assay in PALMD-overexpressing cells. Empty vector as a control (green fluorescent protein (GFP)) and GFP-tagged PALMD (GFP-PALMD) were transfected into U2OS cells. Cells were left untreated or treated with ADR and incubated for 6 h. Apoptotic cells were analyzed with TUNEL-positive cells. *P<0.01. (d) The transfection efficiency of GFP and GFP-PALMD into U2OS cells. (e) Cell viability in PALMD-depleted cells. U2OS cells were seeded in 96-well plates and transfected with non-silencing siRNA or siPALMD-1 and treated with ADR. The MTS assay was performed after 24 h incubation. The data represent the mean±S.D. from three independent experiments, each performed in triplicates