癌胚抗原分泌性肿瘤患者外周血中癌胚抗原mRNA的表达

Carcinoembryonic antigen mRNA expression in peripheral blood of patients with carcinoembryonic antigen-producing tumors

目的观察外周血中癌胚抗原（ＣＥＡ）分泌性肿瘤标志基因的表达。方法设计特异的引物，用逆转录ＰＣＲ方法检 测正常人及肿瘤病人外周血有核细胞成分中的 ＣＥＡ ｍＲＮＡ。结果 ４６例肿瘤患者中有 ２５例检出 ＣＥＡ ｍＲＮＡ，阳性率 为５４．３５％；正常对照者 １２例均阴性。肿瘤临床分期为Ⅲ、Ⅳ期的患者血清ＣＥＡｍＲＮＡ检出率明显高于Ⅰ、Ⅱ期的病人 （Ｐ＜０．０５）。 ＣＥＡ ｍＲＮＡ阳性率与血清 ＣＥＡ水平无显著性关系（Ｐ＜０．０５）。临床有远处转移者 ＣＥＡ ｍＲＮＡ阳性率明显高 于无远处转移者（Ｐ＜０．０５）。对临床无远处转移征兆，而 ＣＥＡ ｍＲＮＡ检测阳性的 １２例患者进行半年的随访，３例出现脏 器的转移。结论外周血标志基因检测是肿瘤微转移检测的灵敏方法。ＣＥＡｍＲＮＡ阳性率与肿瘤临床分期正相关，与肿 瘤的远处转移密切相关，而与血清ＣＥＡ水平无显著性关系。血中标志基因阳性可能提示肿瘤的早期转移。

Objective To observe the expression of the marker gene of carcinoembryonic antigen (CEA)-producing tumors in the peripheral blood of patients with the malignancy and explore its clinical implications. Methods CEA mRNA expression in the nucleated cells in the peripheral blood of 46 patients and 12 healthy subjects was measured by means of reverse transcriptional polymerase chain reaction with designed specific primers. Results Twenty-five (54.35%) patients were found CEA mRNA-positive, but none in the healthy subjects. The positivity rate of CEA mRNA was obviously higher in the tumor patients of stages Ⅲ and Ⅳ than in those of stages Ⅰ and Ⅱ (P<0.05), which was closely associated with the presence of distant tumor metastasis, but not with serum CEA levels (P<0.05). Distantmetastasis of the primary tumors was found in 3 of 12 CEA mRNApositive patients during the follow-up for half a year who were previously clear of clinical metastatic evidence. Conclusions The positivity rate of CEA mRNA increases with the development of the malignancies. The presence of the marker gene in the peripheral blood can be indicative of early metastasis of the tumors, and the detection of the marker gene, therefore, is sensitive for diagnosing micrometastasis.