Guo Ying, Wang Jingmei, Huang Peilin
Department of Pathology, Nanjing University of Traditional Chinese Medicine, Nanjing 210029, China.
Zhongguo Fei Ai Za Zhi. 2009 Sep 20;12(9):1013-7. doi: 10.3779/j.issn.1009-3419.2009.09.014.
The tumor cells may disseminate into circulation even in early stages. However, the numbers of such cells are so small that they cannot be detected by conventional diagnostic methods. Developments in molecular technology have made it possible to detect small numbers of tumor cells in peripheral blood. In this study, 83 preoperative peripheral blood samples from patients with lung cancer were analyzed for the determination of CEA, CK19, and CK20 mRNA expression in peripheral blood, and its clinical significance was evaluated.
Nested reverse transcriptasepolymerase chain reaction (nested RT-PCR) was used to analyze CEA, CK19, and CK20 mRNA expression in peripheral blood. Fresh tumor tissues from patients with esophageal cancer (n=15) were used as a positive control, and blood samples from 15 healthy volunteers as a negative control.
Among 83 blood samples from patients with lung cancer, the expression of CK20, CK19 and CEA mRNA was 41.0%, 36.1% and 48.2%, respectively. 73.5% were positive for at least one markers for these three genes, and were significantly correlated with the metastasis of the cancer (P<0.05), but had no correlation with age and sex. In primary esophageal tumors, 15 tumor tissues were all positive for CEA, CK19, and CK20 mRNA. 2 of 15 blood samples from healthy donors were positive for CK19 and CEA mRNA, and 1 of 15 blood sample positive for CK20 mRNA.
The three markers of CK20, CK19 and CEA mRNA could be the target genes in detecting circulating tumor cells in peripheral blood from patients with lung cancer. The combined detection of CK20, CK19 and CEA mRNA by RT-PCR assay may contribute to the PCR positivity and sensitivity, and CK20, CK19, CEA mRNA expression increase the specificity.
肿瘤细胞甚至在早期阶段就可能扩散进入血液循环。然而，这类细胞数量极少，无法通过传统诊断方法检测到。分子技术的发展使得检测外周血中少量肿瘤细胞成为可能。在本研究中，分析了83例肺癌患者术前外周血样本中癌胚抗原（CEA）、细胞角蛋白19（CK19）和细胞角蛋白20（CK20）mRNA的表达情况，并评估其临床意义。
采用巢式逆转录聚合酶链反应（巢式RT-PCR）分析外周血中CEA、CK19和CK20 mRNA的表达。15例食管癌患者的新鲜肿瘤组织用作阳性对照，15名健康志愿者的血样用作阴性对照。
在83例肺癌患者的血样中，CK20、CK19和CEA mRNA的表达分别为41.0%、36.1%和48.2%。73.5%的样本至少有这三个基因中的一种标志物呈阳性，且与癌症转移显著相关（P<0.05），但与年龄和性别无关。在原发性食管肿瘤中，15例肿瘤组织的CEA、CK19和CK20 mRNA均呈阳性。15名健康供者的血样中有2例CK19和CEA mRNA呈阳性，15例血样中有1例CK20 mRNA呈阳性。
CK20、CK19和CEA mRNA这三种标志物可能是检测肺癌患者外周血循环肿瘤细胞的靶基因。通过RT-PCR法联合检测CK20、CK19和CEA mRNA可能有助于提高PCR阳性率和灵敏度，且CK20、CK19、CEA mRNA表达可提高特异性。
