The present study aimed to investigate whether the JWA gene can regulate the proliferation, migration and invasion of human breast cancer cells through the MAPK signaling pathway. The role of JWA in proliferation, migration, invasion and apoptosis was investigated in the MDA‑MB‑231 human breast cancer cell line. Following transfection with JWA‑small interfering (si)RNA, the effect of JWA on apoptosis was assessed by Western blot analysis, proliferation was determined using Transwell chambers and cell migration and invasion were analyzed by transwell assay. The expression levels of extracellular signal‑regulated kinase (ERK) 1/2, CSBP/RK/Mpk2 kinase (p38) and c‑Jun N‑terminal kinase (JNK) were detected using Western blot analysis in the siRNA and control groups. The expression of JWA in the breast cancer cells was significantly lower compared with the normal breast cells. Downregulation of JWA protein levels reduced the apoptosis and enhanced proliferation, migration and invasion of the MDA‑MB‑231 cells in vitro. The results of the Western blot analysis demonstrated that, compared with the control groups, the expression levels of phosphorylated (p‑)p38 decreased significantly in the JWA siRNA group. No significant changes were observed in the expression levels of p‑ERK1/2 or p‑JNK. Therefore, the JWA gene may regulate human breast cancer cells through the MAPK signaling pathway using different types of regulation.