Ikeda Jun-Ichiro, Morii Eiichi, Liu Yalan, Qiu Ying, Nakamichi Naoto, Jokoji Ryu, Miyoshi Yasuo, Noguchi Shinzaburo, Aozasa Katsuyuki
Department of Pathology, Graduate School of Medicine, Osaka University, Yamada-oka 2-2, Suita 565-0871, Japan.
Clin Cancer Res. 2008 Aug 1;14(15):4780-6. doi: 10.1158/1078-0432.CCR-07-1844.
Our recent study revealed that CD55-high population in breast cancer cell line was resistant to apoptosis and formed colonies in vitro more efficiently than CD55-low population. The present study was conducted to examine whether CD55-high population in breast cancer cell line possesses higher tumorigenic potential in vivo and presence of CD55-high cells in breast cancer affects clinicopathologic behavior of patients.
CD55-high and CD55-low population was sorted from breast cancer cell line, injected into immunodeficient mice, and the resultant tumor volume was measured. CD55 expression was immunohistochemically examined in clinical samples from 74 cases with breast cancers, and cases with >1% of tumor cells showing high level of CD55 expression were categorized as CD55 high.
The xenotransplanted tumor volume derived from CD55-high population was significantly larger than that from CD55-low population. Fifty (67.6%) of 74 cases of breast cancer were CD55-high. A significant correlation was observed between CD55-high character and relapse rate (P < 0.001). Univariate analysis showed that tumor size (P = 0.005) and CD55 expression (P = 0.005) were unfavorable prognostic factors. Multivariate analysis revealed that the tumor size (P = 0.013) and CD55 expression (P = 0.011) were independent prognostic factors.
CD55 play an important role in tumorigenesis of breast cancer, and presence of small population of cells with strong CD55 expression would be sufficient to predict poor prognosis of patients.
我们最近的研究表明，乳腺癌细胞系中CD55高表达群体对凋亡具有抗性，并且在体外比CD55低表达群体更有效地形成集落。本研究旨在检测乳腺癌细胞系中CD55高表达群体在体内是否具有更高的致瘤潜力，以及乳腺癌中CD55高表达细胞的存在是否影响患者的临床病理行为。
从乳腺癌细胞系中分选CD55高表达和CD55低表达群体，注射到免疫缺陷小鼠体内，并测量所得肿瘤体积。对74例乳腺癌临床样本进行CD55表达的免疫组织化学检测，肿瘤细胞中CD55高表达水平>1%的病例归类为CD55高表达。
源自CD55高表达群体的异种移植肿瘤体积明显大于源自CD55低表达群体的肿瘤体积。74例乳腺癌中有50例（67.6%）为CD55高表达。观察到CD55高表达特征与复发率之间存在显著相关性（P<0.001）。单因素分析显示肿瘤大小（P=0.005）和CD55表达（P=0.005）是不良预后因素。多因素分析显示肿瘤大小（P=0.013）和CD55表达（P=0.011）是独立预后因素。
CD55在乳腺癌的肿瘤发生中起重要作用，少量具有强CD55表达的细胞的存在足以预测患者的不良预后。
