Detection of cancer cells in the peripheral blood and lung of mice after transplantation of human adenoid cystic carcinoma.

Polymerase chain reaction (PCR) targeting human beta-globin gene has been reported to be able to detect micrometastasis in an animal model. We attempted to detect cancer cells from the lung and peripheral blood in nude mice, into which a human adenoid cystic carcinoma (ACC) line (KOA-1 and KOA-1L3) had been transplanted. Positive PCR reaction was observed in the lung of a total of 19 of 47 (40.4%) mice into which KOA-1 tumor cells had been transplanted: none of 10 after 1 month, seven of 18 after 2 months, and 12 of 19 after 3 months or later. The KOA-1L3 tumor showed earlier lung metastasis, that is, two of 24 after 7 days and two of 12 after 14 days. Positive PCR reaction was confirmed in the blood samples of three of 19 mice. The lungs of these mice were positive PCR results after subcutaneous transplantation of the KOA-1 tumor. Three of four mice in these blood samples were confirmed in Positive PCR reaction after subcutaneous transplantation of the KOA-1L3 tumor similarly. The lungs of these mice were PCR positive reaction as well as the lungs of transplantation KOA-1 tumor mice. On the other hand, negative PCR reaction was showed these lungs of 60 mice after subcutaneous transplantation of the KOA-1 or KOA-1L3 tumor. All of them were showed negative PCR results in the blood samples. This experimental model can be expected to provide a more detailed understanding of ACC, as well as help to develop a therapy for metastasis of ACC.