OBJECTIVE

To investigate the expression of receptor-tyrosine-kinase-like orphan receptor 1 (ROR1) and its role in cell growth in human colorectal carcinoma (CRC).

METHODS

Real-time quantitative PCR (qRT-PCR) and immunohistochemistry (IHC) were used to detect the expression of ROR1 in CRC (n=60) and matched tumor-adjacent tissues. The relationship between the expression of ROR1 and clinical features was analyzed by Pearson chi-square test. siRNA was used to down-regulate the expression of ROR1 in SW480 cells in vitro. The qRT-PCR and Western blotting were performed to confirm the down-regulation of ROR1 expression. The effects of down-regulated ROR1 on cell proliferation and apoptosis were measured by MTT assay and flow cytometry combined with annexin V-FITC/PI staining, respectively.

RESULTS

Both the mRNA and protein expression of ROR1 were significantly up-regulated in CRC tissues than in tumor-adjacent tissues, and the expression of ROR1 was positively correlated with tumor size (≥5 cm), lymphatic metastasis and TNM stage (III and IV). siRNA could significantly down-regulate the expression of ROR1 in SW480 cells, then suppressed proliferation and enhanced apoptosis in SW480 cells.

CONCLUSION

The expression of ROR1 was significantly higher in CRC tissues than in tumor-adjacent tissues. Down-regulation of ROR1 could play an anti-cancer role through inhibiting proliferation and inducing apoptosis in CRC.