Karyopherin-α3 (KPNA3) promotes proliferation, migration, and invasion in triple-negative breast cancer. (A) Expression pattern of KPNA3 protein in different breast cancer subtypes obtained from the UALCAN database, consisting of normal (n = 18), luminal (n = 64), HER2 (n = 10), and TNBC (n = 16) subtypes. (B) mRNA expression pattern of KPNA3 in different breast cancer subtypes. Expression data were obtained from the GENT2 database, consisting of luminal (n = 17), luminal A (n = 379), luminal B (n = 244), HER2 (n = 230), basal (n = 363), and TNBC (n = 251) subtypes. For each subtype, the log2 fold change (FC) was calculated. (C) Survival rate analysis of breast cancer patients according to differential expression levels of KPNA3 obtained from the GENT2 database. Low (n = 252) and high (n = 250) expression levels of KPNA3 were divided by median expression. (D) Expression levels of KPNA3 protein in MDA-MB-231 cells exposed to two siRNAs of KPNA3 (KPNA3-KD) for 48 h by western blot analysis using β-actin as a loading control. (E) Proliferation rates in cells exposed to KPNA3-KD, as examined by the WST-1 assay at various time intervals. Data represent the mean ± standard deviation (SD) of three independent experiments. (F) Cell images of migrated or invaded cells under the same conditions as those in (D) (left panel). The number of migrated or invaded cells (right panel). Data represent the mean number of cells per five visual regions (×100) of three replicate wells.