Sensitive Detection of Minimal Residual Neuroblastoma Cells Using RT-PCR for Tyrosine Hydroxylase mRNA

Sung, Ki Woong; Lee, Yun Hee; Jung, Hye Lim; Koo, Hong Hoe; Shin, Hee Young; Ahn, Hyo Seop

Abstract

PURPOSE: A sensitive assay to detect minimal residual disease (MRD) in neuroblastoma (NBL) is necessary for accurate assessment of disease status and optimal treatment. Reverse transcriptase-polymerase chain reaction (RT-PCR) for tyrosine hydroxylase (TH) mRNA was developed to detect minimal residual NBL cells.
METHODS
Thirteen patients with stage I to IV NBL and one healthy donor were included in this study. Samples for bone marrow (BM) and peripheral blood (PB) were obtained at diagnosis, during treatment, and during follow-up after completion of treatment, and were examined for TH mRNA with RT-PCR.
RESULTS
TH mRNA was detected in NBL cell line and cells obtained from BM with cytologic tumor invasion, but was not detected in normal PB mononuclear cells (MNC). Occult NBL cells were detected at a level of 1 for 105~6 normal PB MNC by this method. TH mRNA was detected in 13 of 28 BM or PB samples. TH mRNA came to be not detected after administration of chemotherapeutic agent. TH mRNA was detected in 1 PB sample harvested for transplantation and was detected in 2 of 5 PB samples obtained from patients who were transplanted with autologous PB stem cells in partial response (PR) state. TH mRNA was not detected in patient transplanted in complete response (CR) state. In recent examinations, TH mRNA was detected in 1 of 7 CRs and in 2 of 6 PRs.
CONCLUSION
RT-PCR for TH mRNA was a sensitive method to detect minimal residual NBL cells. This method can be used to evaluate initial disease status, response to treatment, time to collect stem cells for transplantation, suitability of cellected stem/progenitor cells and to detect relapse early. But the clinical significances of TH mRNA detected by this method require further investigation.