PBX1 Increases the Radiosensitivity of Oesophageal Squamous Cancer by Targeting of STAT3.

The radioresistance of oesophageal squamous cell carcinoma (OSCC) is a critical factor leading to a poor prognosis among patients. The expression of PBX1 is abnormally high in a broad range of human tissues, and this gene plays a key role in tumour proliferation. This research intended to explore the radiosensitization of OSCC by silencing PBX1. The OSCC cell lines KYSE450 and KYSE150 were subjected to PBX1 silencing and/or irradiation (IR). Cell proliferation, colony formation, and apoptosis were tested to evaluate the radiosensitization ability of PBX1 silencing. The levels of STAT3 and p-STAT3 in the OSCC cells were tested by Western blotting. Furthermore, KYSE150 cells with or without PBX1 silencing were xenografted into nude mice with or without radiation exposure. Concomitant PBX1 silencing and IR can obviously suppress growth and enhance radiosensitivity in OSCC cells and xenografts. Moreover, the downregulation of PBX1 inhibits the expression of STAT3 and p-STAT3. The downregulation of PBX1 may increase radiosensitivity in OSCC cells and xenografts via the PBX1/STAT3 pathway. Our findings demonstrate that PBX1 may be a potential target for promoting the effect of radiation therapy in OSCC patients.