HOXB5-activated ANGPT2 promotes the proliferation, migration, invasion and angiogenic effect of esophageal cancer cells via activating ERK/AKT signaling pathway

Esophageal cancer, which is the eighth most common cancer worldwide, has a poor prognosis and high mortality rate. The present study was designed to investigate the proliferation, migration, invasion and angiogenic effect of the homeobox B5 (HOXB5)/angiopoietin-2 (ANGPT2) interplay in esophageal cancer. The relative expression of ANGPT2 and HOXB5 in esophageal cancer and the association between gene expression was evaluated using data from Gene Expression Profiling Interactive Analysis databases. Following transduction of short hairpin RNA-ANGPT2#1/2 plasmids, ANGPT2 was silenced. Viability, proliferation and invasion of esophageal cancer cells were assessed using CCK-8, 5-EdU, colony formation, wound healing and Transwell assays, respectively. Moreover, the transcriptional activity of ANGPT2 and angiogenesis were detected with luciferase reporter, chromatin immunoprecipitation (CH-IP) and tube formation assays. The results of the present study indicated that ANGPT2 was upregulated, both in esophageal cancer cell lines and tissue and there was an association between the ANGPT2 upregulation and the poor patient prognosis. In addition, ANGPT2 silencing suppressed esophageal cancer cell proliferation, migration, invasion and angiogenesis. The HOXB5 expression was also increased in esophageal cancer, and transcriptionally activated ANGPT2. Moreover, HOXB5 overexpression reversed the effects of ANGPT2 silencing in esophageal cancer cells. Furthermore, ANGPT2 silencing inactivated ERK/AKT signaling, whereas the HOXB5 overexpression blocked this effect. In conclusion, ANGPT2, which was transcriptionally activated by HOXB5, activated the ERK/AKT signaling pathway to promote proliferation, metastasis and angiogenesis of esophageal cancer cells.