2000 Volume 5 Issue 2 Pages 71-76
To establish early diagnosis of lymph node metastasis, reverse transcriptase polymerase chain reaction (RT-PCR) for cytokeratin 19 (CK19) mRNA was evaluated in detecting tumor cells in blood and lymph nodes in an animal model of squamous cell carcinoma (termed O-1 N) with high potential of lymph node metastasis. RT-PCR using primers for CK19 cDNA designed from human counterparts produced a single band of CK19 product which showed high homology with human and mouse CK19 s. CK19 mRNA was expressed in O-1 N cells, but not of blood and lymph nodes, indicating that CK19 mRNA is a good target of RT-PCR. In a spiking experiment, tumor cells diluted to 102 cells/2 ml of blood were detected by RT-PCR. The presence of tumor cells in blood was detected much earlier than the occurrence of lymph node and lung metastases. These results indicate that CK19 mRNA in blood can be used as a predicting marker for lymph node metastasis.
