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

应用RT-PCR方法比较了口腔鳞癌原发灶和微转移灶外周血中细胞角蛋白19（CK 19）、CD 44及其变异体（s、v6、v9）mRNA的表达。采用免疫磁性分离技术收集微转移癌细胞，激光捕获显微切割法获得原发癌细胞。5 ml血液中可捕获50个癌细胞，包被人上皮抗原特异性抗体的免疫球可有效捕获癌细胞. CK 19 mRNA在约一半的原发癌细胞和循环癌细胞中表达.原发癌细胞不表达CD 44 mRNA，而外周血中大部分癌细胞表达CD 44及其变异体的mRNA. MMP（2，7，9）mRNA在原发癌细胞上表达，而在循环癌细胞上不表达.通过将舌癌细胞系（SCCC、SAS或N2 NA）移植到裸大鼠体内，制备转移性病变（肺、淋巴结），并检测上述mRNA在原发性和转移性病变中的表达，这些结果表明原发性和循环癌细胞之间的基因表达可能不同。

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.