Overexpression of HOXB7 protein reduces sensitivity of oral cancer cells to chemo-radiotherapy.

The upregulation of homeobox-B7 (HOXB7) in cancers has been reported. However, its role in oral cancer progression remains to be investigated. In current study, our data revealed that reconstitution of HOXB7 expression by transient transfection resulted in increased cell growth, migration and invasion in vitro. In addition, apoptosis and clonogenic assay data showed that overexpression of HOXB7 decreased the sensitivity of oral cancer cells to vincristine-induced apoptosis of HSC-4 and KB/VCR cells. Furthermore, overexpression of HOXB7 promoted oral cancer cells' migration and invasion through activation of TGFβ2/SMAD3 signaling pathway. Moreover, forced expression of HOXB7 increased Bcl-2 to Bax ratio, which would promote cell survival and induce drug and radiotherapy resistance. Altogether, our findings support the role of HOXB7 in the progression of oral cancer. Therefore, HOXB7 potentially can be a therapeutic target for oral cancer.