Overexpression of ribonuclease inhibitor defines good prognosis and suppresses proliferation and metastasis in human colorectal cancer cells via PI3K/AKT pathway.

PURPOSE

We aim to evaluate the diagnostic value of ribonuclease inhibitor (RI) in colorectal cancer (CRC) and investigate the important role of RI in cell growth and metastasis of CRC.

METHODS/PATIENTS: In this study, the expression of RI was evaluated in human CRC samples with different histological grade and the association between RI expression and clinicopathological parameters was investigated. Furthermore, the exogenous RI gene was introduced into human HT29 CRC cells and the effects of RI on cell proliferation and metastasis were determined in vitro. The PI3K/Akt signaling pathway and some related protein molecules were detected.

RESULTS

RI is downregulated in CRC tissues compared to adjacent normal tissues and its expression is inversely associated with histological grade, pathological stage, and venous invasion, respectively. Multivariate analysis showed that RI expression was an independent prognostic factor for overall survival. In addition, the exogenous overexpression of RI reduced the proliferation and migration of HT29 CRC cell line in vitro by inhibiting the PI3K/Akt signaling pathway and suppressing the expression of vascular endothelial growth factor (VEGF) and upregulating phosphatase and tensin homolog (PTEN).

CONCLUSIONS

RI represents an important predictor of progression in patients with CRC and suppresses proliferation and metastasis in CRC cells through inhibiting PI3K/AkT pathway.