Overexpression of fibrinogen-like protein 2 induces epithelial-to-mesenchymal transition and promotes tumor progression in colorectal carcinoma

The main cause of death in colorectal carcinoma (CRC) patients is tumor metastasis; however, the underlying molecular mechanisms are largely unknown. In the present study, a novel metastasis-related gene, fibrinogen-like protein 2 (FGL2), was characterized for its role in CRC metastasis and underlying molecular mechanisms. The clinical significance of FGL2 was investigated using tissue microarray analysis of samples from 82 patients with CRC. The molecular effects of FGL2 in CRC cells were determined using RNA interference and ectopic expression of FGL2. The overexpression of FGL2 was examined by immunohistochemistry in 82 CRC patients, and it was determined to be an independent predictor of overall survival (P < 0.05). The depletion of FGL2 expression inhibited tumor progression and epithelial-to-mesenchymal transition (EMT) in vitro and in vivo, while ectopic overexpression of FGL2 enhanced cell invasion and induced EMT in vitro. Our results suggest that FGL2 plays an important oncogenic role in CRC aggressiveness by inducing EMT, and FGL2 could be employed as a novel prognostic marker and effective therapeutic target for CRC.