The expression and functional role of FOX transcription factor FOXJ1 in prostate cancer

As one common malignant tumor in male reproductive-urinary system, the incidence of prostate cancer is increasing rapidly. Recent study revealed the participation of FOX transcription factor family in tumor occurrence and progression. FOXJ1, one member of FOX family, plays an important role in tumor pathogenesis and advancement, although its expression and functional role in prostate cancer has not been illustrated. Both tumor and adjacent tissues were collected from prostate cancer patients. Real-time PCR and Western blot were used to test the FOXJ1 expressions, and to analyze their correlation with pathological feature of cancer. DU145 cells were in vitro cultured and were transfected with FOXJ1-overexpressing vectors. MTT assay detected the effect of FOXJ1 on tumor cell proliferation. Western blot quantified MMP-2 and MMP-9 expressions, while Transwell invasion assay determined the impact of FOXJ1 on tumor invasion. Both mRNA and protein levels of FOXJ1 in prostate tumor tissues were significantly depressed compared to adjacent tissues (P<0.05). FOXJ1 expression level was negatively correlated with TNM stage, tumor volume and lymphatic metastasis (P<0.05). The transfection of DU145 cells by FOXJ1-overexpressed vectors inhibited proliferation or invasion abilities, and reduced MMP-2 and MMP-9 expressions (P<0.05 compared to control group). FOXJ1 was down-regulated in prostate cancer tissues, and was closely correlated with pathological features of tumor. FOXJ1 regulated proliferation of prostate cancer cells, and functioned as molecular targets for tumor diagnosis and prognostic prediction via modulating MMP-2 and MMP-9 mediated tumor invasion.