Prognostic Significance of CDCP1 Expression in Colorectal Cancer and Effect of Its Inhibition on Invasion and Migration

To assess the correlations and functions of complement C1r/C1s, Uegf, Bmp1 domain-containing protein-1 (CDCP1) in identifying colorectal cancer (CRC) patients who are at high risk for metastasis. Tumor specimens from 101 patients were analyzed by real-time polymerase chain reaction to detect CDCP1 expression. CDCP1 expression plasmids and shRNA were used to knock down CDCP1 expression in this study to investigate migratory and invasive abilities by Boyden chambers. The mRNA expression profiles in shCDCP1 transfectants were compared to those in control cells by conducting microarray analysis. Its downstream effectors were also invested in this study. CRC patients with a high CDCP1 expression had a statistically significant lower overall survival and disease-free survival compared to those exhibiting low CDCP1 expression. In vitro, knock-down CDCP1 expression significantly decreased migratory and invasive abilities in HCT116. Aberrant expression of CDCP1 increased cancer cell migration and invasion. By using integrated genomics, we identified ROCK1 (rho-associated, coiled-coil-containing protein kinase 1 pseudogene 1) as a downstream effector in CDCP1-mediated migration and as an invasion mediator. Clinically, ROCK1 and CDCP1 mRNA expression exhibited a strong positive correlation in CRC patient samples. Our results implicated CDCP1 as a key regulator of CRC migration and invasion, and suggest that it is a useful prognostic factor for patients with CRC. Improved identification of a high-risk subset of early metastatic patients may guide indications of individualized treatment in clinical practice.