Silencing of HOXB9 suppresses cellular proliferation, angiogenesis, migration and invasion of prostate cancer cells.

The Homeobox B9 (HOXB9) is a homeodomain-containing transcription factor that participates in the progression of various malignancies. Nevertheless, the functional role of HOXB9 in prostate cancer cells is largely unknown. Hence, we aimed to address the effect of HOXB9 on the progression of prostate cancer cells. Small interfering RNA (siRNA) against HOXB9 was used to downregulate HOXB9 expression in PC3 and DU145 cells. Western blotting was performed to detect the expression levels of HOXB9 and other related proteins. Cell proliferation was tested by the Cell Counting Kit-8 (CCK-8) and cell cycle and apoptosis were investigated by flow cytometry. Angiogenesis was examined using tube formation assays The Transwell assays were carried out to assess the migratory and invasive capacities of cells. Here, we found that HOXB9 knockdown significantly reduced cell proliferation via inducing cell cycle arrest at G1 phase. This treatment also reduced angiogenesis, migration and invasion abilities of PC3 and DU145 cells in vitro. We also found that HOXB9 knockdown inhibits the activation of the PI3K/AKT signaling pathway in prostate cancer cells. In conclusion, our findings revealed that HOXB9 promotes prostate cancer progression and might be a novel and effective therapeutic target for human prostate cancer.