Reticulocalbin 2 correlates with recurrence and prognosis in colorectal cancer

Reticulocalbin (RCN) family members could play oncogenic roles in human malignancies and facilitate tumor cell proliferation and metastasis. However, the expression pattern and potential function of Reticulocalbin 2 (RCN2) in colorectal cancer has not been addressed yet. In the present study, we investigated the protein expression of RCN2 by immunohistochemistry assay, and analyzed its association with tumor progression, recurrence and prognosis in 326 cases of patients. Results suggested that the expression of RCN2 was up-regulated in colorectal cancer compared with paired adjacent nontumor specimens. RCN2 expression was closely related to tumor size and the depth of invasion. Kaplan-Meier analysis proved that RCN2 was associated with both disease-free survival and overall survival of patients with colorectal cancer. Moreover, cox's proportional hazards analysis showed that high RCN2 expression was an independent prognostic marker of poor outcome. Consistently, overexpressing RCN2 promoted CRC cell proliferation both in vitro and in vivo and knockdown RCN2 showed the opposite results. These results provided the first evidence that RCN2 level was increased in colorectal cancer and significantly correlated with tumor growth and proliferation. It also indicated that RCN2 might serve as a potential marker of tumor recurrence and prognosis of colorectal cancer.