Fig. 3

PDCD4 negatively regulate SKP2 protein levels and SKP2 increases the survival of breast cancer cells via PDCD4 suppression. a MCF7-Con and MCF-7-SKP2 cells were transfected with control or Flag-PDCD4 plasmid, selected and harvested for IB. b MDA-MB-231-Con and MDA-MB-231-sgSKP2 cells were transfected with control or shPDCD4 plasmid, selected and harvested for IB. c, e MCF-7-Con, MCF-7-SKP2 and MCF-7-SKP2 with PDCD4 stable expression cells were untreated or treated with radiation (6GY), followed by MTT assay and clonogenic survival assay (n = 3). d, f MDA-MB-231-Con, MDA-MB-231-sgSKP2 and MDA-MB-231-sgSKP2 with shPDCD4 stable expression cells were treated with radiation (6GY), followed by MTT assay and clonogenic survival assay (n = 3). g MCF-7-Con, MCF-7-SKP2 and MCF-7-SKP2 with PDCD4 stable expression cells were subcutaneously injected into nude mice (n = 5 for each group). A photo of five tumors aligned together were presented. h Tumor weight was measured. i Tumor size was monitored and calculated by caliper for up to 6 weeks. j Breast tumors were harvested from nude mice at 6 week for Ki-67 staining by IHC and quantitated (Scale bars, 50 um, Scale bars inside the box, 20 um). k MDA-MB-231-Con, MDA-MB-231-sgSKP2 and MDA-MB-231-sgSKP2 with shPDCD4 stable expression cells were subcutaneously injected into nude mice (n = 5 for each group). A photo of five tumors aligned together were presented. l Tumor weight was measured. m Tumor size was monitored and calculated by caliper for up to 6 weeks. n Breast tumors were harvested from nude mice at 6 week for Ki-67 staining by IHC and quantitated (Scale bars, 50 um, Scale bars inside the box, 20 um). c-f, h-j, l-n Data represent the mean ± SEM of three independent experiments. Student’s t-test used: *P < 0.05; **P < 0.01