The clinical significance of forkhead box protein A1 and its role in colorectal cancer.

Forkhead box protein A1 (FOXA1) is a transcription factor; recent studies have reported that FOXA1 has an oncogenic or tumor suppressive role in human malignancies, and its expression is associated with the prognosis of patients with cancer. However, further studies are required to determine the clinical significance of FOXA1 and its role in colorectal cancer (CRC). In the present study, FOXA1 expression was detected in 90 samples of CRC tissues and matched noncancerous tissues using immunohistochemistry. In these cases, FOXA1 expression was detected in 57.8% (52/90) of the CRC samples, whereas only 37.8% (34/90) of the noncancerous specimens exhibited a positive FOXA1 signal. In addition, the present study demonstrated that the mRNA expression levels of FOXA1 were significantly increased in CRC tissues compared with in matched tumor‑adjacent tissues. Furthermore, the positive expression of FOXA1 was associated with poor clinicopathological characteristics of CRC, including poor tumor differentiation, large tumor size, lymph node metastases and advanced tumor‑node‑metastasis tumor stage. Notably, patients with CRC with positive FOXA1 expression exhibited a significantly reduced 5-year survival rate compared with those with negative FOXA1 expression. Multivariate Cox regression analysis revealed that FOXA1 expression was an independent prognostic indicator for patients with CRC. In addition, FOXA1 knockdown evidently inhibited cell proliferation and induced apoptosis in SW480 and HCT116 CRC cells. Notably, FOXA1 knockdown also prominently reduced the expression of yes‑associated protein (YAP) in SW480 and HCT116 cells. In conclusion, the results of the present study indicated that FOXA1 may be considered a potential prognostic marker, and may promote tumor growth of CRC by upregulating YAP expression.