肿瘤相关抗原在人大肠癌中的表达

Expression of Tumor-associated Antigen in Colorectal Carcinoma

目的应用ND-1单抗和抗CEA单抗对大肠癌细胞的标记情况对比,探讨LEA在大肠癌中的表达及意义。方法采用流式细胞仪和免疫细胞化学染色检测大肠癌细胞系LEA和CEA的表达。并采用间接ELISA法测定LEA和CEA单抗对大肠癌细胞系的特异性。应用免疫组化检测其在大肠癌组织中的表达。结果流式细胞仪检测显示,LEA抗原在CCL-187、CX-1、CLone A和CCL-229细胞表达的阳性峰平均荧光强度呈递减趋势,并且强于CEA的表达量(P<0.01)。LEA在高分化大肠癌细胞系CCL-187和CX-1高度表达,并且低侵袭大肠癌细胞系CCL-187和CX-1LEA表达量高于高侵袭大肠癌细胞系CLoneA和CCL-229(P<0.01)。ELISA检测表明,与抗CEA单抗相比,ND-1单抗对大肠癌细胞具有很强的特异性结合力(P<0.01)。LEA的表达阳性率随大肠腺癌组织分化程度降低而下降(P<0.01),而且对高分化腺癌表现出更高的选择性。抗CEA单抗对高、中、低分化癌选择性相似(P>0.05)。结论LEA是更加特异的高分化大肠癌相关抗原。LEA可能与癌细胞的分化程度、侵袭力、恶性程度有关,LEA可作为早期诊断和判断大肠癌恶性程度的有用指标。

Objective This study was designed to evaluate the expression and its significance of colorectal carcinoma-associated antigen LEA in colorectal carcinoma cells through the comparison of a new monoclonal antibody （ND-1） and anti-CEA monoclonal antibody. Methods Expression of LEA and CEA in colorectal carcinoma cells was detected with immunocytochemistry and flow cytometry. The specificity of LEA and CEA in colorectal cancercells was analyzed by ELISA, and to detect the expression of LEA in colorectal cancer tissues with immunohistochemical method. Results Flow cytometry detection showed that positive peak mean fluorescence intensity was gradually decreasing in the expression of LEA in CCL- 187,CX-1,CLoneA and CCL-229,and stronger than that of CEA（P〈0. 01 ）. LEA was highly expressed in the well differentiated colorectal cancer cells of CCL 187 and CX-1, and its expression amount in low invasive cell lines of CCL-187 and CX-1 was higher than high invasive ones of CLoneA and CCL-229（P〈 0. 01）. ELISA analysis revealed that monoclonal antibody ND-1 had stronger specific binding activity to the colorectal carcinoma cell lines as compared to the CEA （P〈0.01）. The expression of LEA was decreased following the drop of tumor differentiation degree（P〈0. 01 ）and exhibited higher selectivity in well differentiated colorectal cancer （P〈 0. 01）. CEA had similar selectivity in well,moderately,and poorly differentiated colorectal cancer（P〈 0. 05）. Conclusion LEA is more specific well differentiation colorectal carcinoma-associated antigen. LEA may be related to the differentiation degree, invasiveness and malignancy degree of cancer cells. LEA can be used as a useful measurement for the early diagnosis and malignancy degree of colorectal carcinoma.