Paired box gene 4 (PAX4) is a transcriptional modulator located on chromosome 7q32, and its expression is dysregulated in a variety of human cancers, suggesting that PAX4 may be important in multiple tumors as a driver gene. Here, we show that PAX4 promoted migration and invasion in human epithelial cancers by decreasing miR-144 and miR-451 (miR-144/451) expression levels. Accordingly, miR-144/451 suppressed the migratory and invasive phenotypes, even in PAX4-expressing cells. Mechanistically, miR-144/451 inhibits cancer metastasis by targeting the A disintegrin and metalloproteinase (ADAM) protein family members ADAMTS5 and ADAM10. Their dysregulation is associated with increased tumor invasiveness and metastasis, then reduced patient prognosis in certain epithelial cancers. This discovery suggests that a PAX4-miR-144/451-ADAMs axis regulates human epithelial cancer metastasis, thus opening up therapeutic possibilities and predicting prognosis for those cancer types.