Pilot Study to Evaluate MYCN Expression as a Neuroblastoma Cell Marker to Detect Minimal Residual Disease by RT-PCR

Abstract

This pilot study was performed to determine whether MYCN expression warrants further investigation as a tumor marker to detect low levels of residual neuroblastoma (NB). Seven NB cell lines and 30 bone marrow (BM) samples from patients with high-risk NB were analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR) for MYCN expression, and for the established NB marker tyrosine hydroxylase. MYCN was expressed in all 7 NB cell lines, but not in normal peripheral blood, CD34 cells, or BM. In dilution studies using cell lines with or without DNA amplification of MYCN, 1 NB cell in 10 to 10 nucleated blood cells was detectable by RT-PCR. MYCN was identified in all 21 BM samples in which tumor cells were identified by histologic examination, including 4 samples in which tyrosine hydroxylase was not detected. Additionally, expression of both markers was detected in 5 samples that were negative by histology but presumably contained low levels of tumor cells, consistent with the greater sensitivity of RT-PCR compared with morphologic methods. Detection of MYCN RNA was independent of MYCN DNA amplification status. The selective expression of MYCN in tumor cells, and the sensitivity of detection of MYCN by RT-PCR noted in this and other studies, supports further evaluation of MYCN as a NB marker for molecular detection of minimal residual disease.

Consensus criteria for sensitive detection of minimal neuroblastoma cells in bone marrow, blood and stem cell preparations by immunocytology and QRT-PCR: recommendations by the International Neuroblastoma Risk Group Task Force

“…Interestingly a combination of techniques or targets might provide not only prognostication about the clinical significance of MD but could also provide additional biologically relevant information. expression of specific target mRNAs may identify profiles that are prognostic or predictive of the behaviour of the metastatic tumour cell (Wagner et al, 2006;Grau et al, 2009). Alternatively analysis using multiple complementary methods may be valuable to define prognostic/predictive groups, for example the coupling of anti-G D2 antibodies with antibodies against proliferation markers or with DNA probes capable of detecting genetic alterations of prognostic significance (Méhes et al, 2001).…”