Overexpression of HOXB9 promotes metastasis and indicates poor prognosis in colon cancer.

Objective: Homeobox B9 (HOXB9) is proposed to be involved in tumor angiogenesis and metastasis. We investigated the role of HOXB9 in the progression of colon cancer.

Methods: HOXB9 expression was investigated by immunohistochemically and Western blotting in 128 colon cancer patients and the results were analyzed statistically associated with clinicopathological data and survival of the patients. The effect of HOXB9 on cell invasion and metastases abilities were analyzed in vitro and in vivo.

Results: HOXB9 is overexpressed in colon cancer tissues and significantly correlated with metastasis and poor survival of patients (P<0.05, respectively). Additionally, high levels of expression of HOXB9 were observed in metastatic lymph nodes. The down-regulation of HOXB9 expression can inhibit the migration and invasive ability of colon cancer cells, while exogenous expression of HOXB9 in colon cancer cells enhanced cell migration and invasiveness. Moreover, stable knockdown of HOXB9 reduced the liver and lung metastasis of colon cancer in vivo.

Conclusions: HOXB9 may play an important role in the invasion and metastasis of colon cancer cells and may be a useful biomarker for metastasis and prognostic of colon cancer.