Figure 3.

Knockdown of FOXM1 attenuates cell proliferation in CRPC cells and regulates expression of DNA-repair-related genes. (A) Schematic of FOXM1 mRNA including individual sites of three siRNA binding sites. (B, C) PC-3 and 22Rv1 cells were transiently transfected with three FOXM1 siRNAs (siFOXM1-1, siFOXM1-2 and siFOXM1-3, respectively) or negative control siRNA (siNC). After 48 hr of transfection, FOXM1 mRNA (B) and protein (C) expression was determined by qRT-PCR and western blot analyses, respectively. (D) PC-3 and 22Rv1 cells were transfected with siFOXM1 or siNC. Cell viability was measured using the WST assay at the indicated time point. (E) Heat map of differentially expressed genes (fold change > 1.5; P < 0.05) in PC-3 cells transfected with siFOXM1 or siNC. (F) Venn diagram of differentially expressed genes identified using gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Overlap between the two circles represents 29 genes, DNA-repair-related genes. HR: homologous recombination; FA: Fanconi anemia; BER: base excision repair; NER: nucleotide excision repair; MMR: mismatch repair. (G, H) PC-3 and 22Rv1 cells were transfected with siFOXM1 for 48 hr (G) or were incubated with 2.5 μM niclosamide for 48 hr (H). mRNA expression was quantified using qRT-PCR. β-actin mRNA was used as an internal control to normalize the data. Data in (B, D, G, and H) are presented as the mean sed as an internal control to normalize the data. RP < 0.01, ***P < 0.001, two-tailed Student’s t test or one-way ANOVA test.