Aberrant expression of CD227 is correlated with tumor characteristics and invasiveness of breast carcinoma.

Increasing evidences demonstrate that CD227 plays a crucial role in the development and progression of breast cancer. However, the function of CD227 in breast carcinoma was still controversial and the investigation on CD227 in Asian race was scarce. To investigate the relationship between CD227 and tumor characteristics of breast carcinoma, CD227, estrogen receptor (ER), progesterone receptor (PR), Her2⁄neu and Ki-67 were detected by immunohistochemistry in a series of 227 patients. The Kaplan-Meier method and log-rank tests were used to estimate the correlation between CD227 expression and patients' prognosis. Furthermore, in vitro invasion assay was performed to examine the effect of CD227 on the invasiveness of breast carcinoma cells after transfection with CD227 cDNA or antisense phosphorothioate oligodeoxynucleotides (ASODN) against CD227 mRNA. Our data demonstrate that the cytoplasm staining and high expression of CD227 were positively related to the aggressiveness of breast cancer. Both circumferential membrane staining and cytoplasm staining were associated with lymph node metastasis. Moreover, the cytoplasm staining and overexpression of CD227 were found to be related to Her-2/neu positivity, higher Ki-67 positivity and poorer survival of patients. We further demonstrated that the invasion ability of breast carcinoma cells could be enhanced or inhibited by CD227 cDNA or ASODN, respectively. We conclude that the aberrant expression of CD227, especially cytoplasm staining could be predictive for tumor aggressiveness, lymph node metastasis, poorer outcome of patients with breast cancers. And CD227 could promote the invasion ability of breast cancer cells, suggesting a potential role of CD227 as an oncogene in breast carcinoma.