NEUROBLASTOMA CELL DETECTION BY REVERSE-TRANSCRIPTASE POLYMERASE CHAIN-REACTION (RT-PCR) FOR TYROSINE-HYDROXYLASE MESSENGER-RNA

The presence of tumour cells in peripheral blood or neuroblastoma pati ents is of considerable clinical importance. Nucleic acid amplificatio n offers an opportunity to detect very small numbers of such cells, bu t in neuroblastoma a frequent specific abnormality in the tumour DNA s uitable for this purpose has yet to be identified. To facilitate the d etection of such cells we have developed RT-PCR using tyrosine hydroxy lase (TH) as a tissue-specific target gene. TH mRNA was detected in 3 neuroblastoma cell lines and in all neuroblastoma tumours examined, bu t was undetectable in peripheral blood from children without neuroblas toma. The method was highly sensitive, detecting 1-10 neuroblastoma ce ll per 10(7) blood cells. Thirty blood samples from 24 patients were a nalysed and results were compared with known disease status. At diagno sis 4/7 patient blood specimens were positive; the four positive sampl es were from stage-4 patients. In blood samples from these patients 6- 8 weeks after the initiation of treatment, TH mRNA was undetectable. O f 7 samples taken at the time of clinical relapse, 5 were positive; 4 of these were from patients with evidence of disseminating disease. Of 16 blood samples from disease-free patients, 14 were negative and 2 w ere positive. One positive patient in this group subsequently hd a cli nical relapse. These results show that this technique is of value for detecting neuroblastoma cells in peripheral blood. The significance of these cells at diagnosis, during treatment or on follow-up requires f urther evaluation. (C) 1994 Wiley-Liss, Inc.