Development of detection method of metastasis from squamous cell carcinoma of head and neck using peripheral blood

采用逆转录聚合酶链式反应(RT-PCR)的方法，比较了细胞角蛋白19(CK19)、CD44及其变异体(S、V6、V9)在口腔鳞癌原代细胞及其外周血微转移癌细胞中的表达。用免疫磁分离技术收集微转移癌细胞，用激光捕获显微切割法获得原代癌细胞，结果如下：1.包被人上皮抗原特异性抗体的免疫小球可以捕获5ml血液中的50个癌细胞。约一半的原代癌细胞和循环癌细胞表达CK19基因。CD44在原代癌细胞上不表达，而外周血中的癌细胞大部分表达CD44及其变异体的mRNA。原代癌细胞表达MMP2、7、9mRNAs，而在循环癌细胞上通常不表达。将舌癌细胞系(SCCC、SAS或N2NA)移植到裸鼠体内，造成肺、淋巴结转移灶，检测原发灶和转移灶细胞上上述mRNAs的表达，提示原代和循环癌细胞的基因表达可能存在差异。

We compared the expression of cytokeratin 19 (CK19), CD 44, and its variant forms (s, v6, v9) mRNAs on primary oral squamous carcinoma cells and their micrometastatic cancer cells in peripheral blood by using RT-PCR method. The micrometastatic cancer cells were collected by an immunomagnetic separation technique and the primary cancer cells were obtained by a laser-captured microdissection method.The results obtained were as follows :1. Fifty cancer cells in 5 ml of blood could be captured by immunobeads coated with specific antibody for human epithelial antigen.2. The expression of CK19 mRNA was detected in about half of the primary and circulating cancer cells.3. CD44 mRNA was not expressed on the primary cancer cells, whereas most of cancer cells in peripheral blood expressed mRNA of CD44 and its variant forms.4. MMP (2, 7, 9) mRNAs were expressed on the primary cancer cells, but they were not usually expressed on circulating cancer cells.5. Metastatic lesions (lung, lymph node) were made by transplanting tongue cancer cell lines (SCCC, SAS or N2NA) into nude rats and the expression of above-mentioned mRNAs on cells in primary and metastatic lesions are now being examined.These results indicate that the gene expression might be different between primary and circulating cancer cells.