肿瘤干细胞标志CD166在结肠癌中的表达及其临床生物学意义

Expression of CD166 in colon cancer and its biological significance

目的探讨肿瘤干细胞标志CD166在原发结肠癌组织中的表达及其临床生物学意义。方法收集57例患者的原位结肠癌组织,应用免疫组织化学检测其CD166表达。应用流式细胞分选(FACS)技术,以CD166/CD133标志分选结肠癌细胞株SW620,通过NOD/SCID小鼠脾脏移植,观察肝转移情况。结果 CD166可表达于结肠癌细胞的细胞质和细胞膜,其中细胞质阳性率98.2%(56/57),细胞膜阳性率42.1%(24/57)。膜CD166阳性表达与局部浸润(P=0.01 0)、pTNM分期(P=0.035)、远处转移(P=0.013)、年龄(P=0.026)相关;而与性别(P=0.426)、淋巴结转移(P=0.104)、肿瘤分化(P=0.171)无相关性。Log-rank生存分析显示:结肠癌细胞膜CD166阳性表达与患者生存期(P=0.014)呈负相关。动物实验的初步结果显示:脾包膜接种CD166阳性的SW620细胞可形成肝转移灶。结论 CD166阳性表达与肿瘤局部进展和远处转移有关,是判断预后不良的标志,CD166阳性的肿瘤细胞可能具有肝转移潜能。

Objective To investigate the expression and biological significance of CD166 in primary colon cancer. Meth- ods The expression of CD166 was detected by immunohistochemistry in tissue specimens from 57 patients with colon cancer of various pTNM stages. Human colon cancer SW620 cells were screened for positive expression of CD166 and CD133. The CD166 and CD133-positive SW620 cells were inoculated in spleen of NOD/SCID mice; then the ability of liver metastases of transplanted SW620 tumors was evaluated. Results The CD166 was positively expressed in cytoplasm and membrane of colon cancer cells, being 98.2% （56/57） in cytoplasm and 42.1% （24/57） in membrane of cancer cells. CD166 membrane expression was significantly associated with older age（P=0.026）, tumor stage （P=0.035）, and distance metastasis（P=0.013）, not with gender（P =0.426）, lymph node metastasis （P=0.104） and tumor differentiation （P =0.171）. Log-rank survival analysis revealed that CD166 membrane ex- pression was negatively correlated with the survival of patient （P=0.014）. The results of the animal experiments demonstrated metastatic growth in the liver after splenic capsule injection CD166＋ SW620 cells. Conclusion The expression of membrane CD166 is associated with poor clinical outcome and short survival in the patient with colon cancer. CD166＋ colon cancer cells may have a potential of liver metastasis.