Knockdown of Homeobox B5 (HOXB5) inhibits cell proliferation, migration, and invasion in non-small cell lung cancer cells through inactivation of the Wnt/β-catenin pathway

Homeobox B5 (HOXB5), a member of the HOX gene family, has been shown to play an important role in tumor progression. However, the expression and functional role of HOXB5 in human non-small cell lung cancer (NSCLC) have not been defined. Thus, the purpose of this study was to elucidate the expression and functional role of HOXB5 in human NSCLC. Our results showed that HOXB5 expression was elevated in human NSCLC tissues and cell lines. The in vitro experiments demonstrated that knockdown of HOXB5 inhibited proliferation, migration, and invasion and prevented the EMT phenotype in NSCLC cells. In vivo experiments indicated that knockdown of HOXB5 attenuated the growth of NSCLC xenografts in vivo. Furthermore, knockdown of HOXB5 suppressed the protein expression levels of β-catenin and its downstream targets c-Myc and cyclin D1 in A549 cells. Taken together, for the first time we have shown that knockdown of HOXB5 significantly inhibited NSCLC cell proliferation, invasion, metastasis, and EMT, partly through the Wnt/β-catenin signaling pathway. These findings suggest that HOXB5 may be a novel therapeutic target for the treatment of NSCLC.