Infantile mediastinal neuroblastoma presenting as an oncologic emergency: usefulness of serum-based MYCN gene amplification analysis for risk stratification

We reported two infantile cases of mediastinal neuroblastoma with life-threatening tracheal obstructions presenting as oncologic emergencies that were successfully treated per tentative risk classification using serum-based MYCN gene amplification (MNA) analysis. Tentative risk stratification based on age, tumour location and serum-based MNA status may be useful in patients with neuroblastoma presenting as oncologic emergencies who require urgent therapy stratification but for whom tumor-based molecular diagnoses cannot be established.

Identification of VRK1 as a New Neuroblastoma Tumor Progression Marker Regulating Cell Proliferation

Neuroblastoma (NB) is one of the most common pediatric cancers and presents a poor survival rate in affected children. Current pretreatment risk assessment relies on a few known molecular parameters, like the amplification of the oncogene MYCN. However, a better molecular knowledge about the aggressive progression of the disease is needed to provide new therapeutical targets and prognostic markers and to improve patients’ outcomes. The human protein kinase VRK1 phosphorylates various signaling molecules and transcription factors to regulate cell cycle progression and other processes in physiological and pathological situations. Using neuroblastoma tumor expression data, tissue microarrays from fresh human samples and patient-derived xenografts (PDXs), we have determined that VRK1 kinase expression stratifies patients according to tumor aggressiveness and survival, allowing the identification of patients with worse outcome among intermediate risk. VRK1 associates with cell cycle signaling pathways in NB and its downregulation abrogates cell proliferation in vitro and in vivo. Through the analysis of ChIP-seq and methylation data from NB tumors, we show that VRK1 is a MYCN gene target, however VRK1 correlates with NB aggressiveness independently of MYCN gene amplification, synergizing with the oncogene to drive NB progression. Our study also suggests that VRK1 inhibition may constitute a novel cell-cycle-targeted strategy for anticancer therapy in neuroblastoma.

MYCN Fish combined with immunohistochemistry is a more prognostic factor for neuroblastoma

Background: MYCN is an identified driver and important prognosticator of neuroblastoma and performs biological function at protein level. At present, most detection methodologies focus on MYCN DNA level and fail to detect MYCN protein expression for poor antibody, especially in China.Results：In the present study, through the analysis of neuroblastoma gene expression profile data, we found MYCN expression is closely related with prognosis of neuroblastoma, especially in stage I-III and IVs at RNA level in current medical conditions. FISH was almost accurate as WES to test MYCN DNA level based on our hospital data. In 56 neuroblastoma cases, IHC analysis by a newfound antibody (#84406s, Cell Signaling Technology) demonstrated a 75%-85% concordance with FISH. Further analyzing those cases with inconsistent results, we found patients with FISH+ but IHC score<9 all had no adverse events, while 63.6% patients with FISH+ and IHC score≥9 tended to have poor outcome. As to those MYCN FISH- patients, once their tumor showed MYCN protein expression, all of them were poor prognosis, while 81% of the rest patients with neither MYCN gene nor protein expression had ideal prognosis.Conclusions: The results suggest that this newfound antibody is reliable in IHC, and IHC combined with FISH performs better in evaluating prognosis and guiding treatment.

Correlation Between MYCN Gene Status and MYCN Protein Expression in Neuroblastoma: A Pilot Study To Propose the Use of MYCN Immunohistochemistry in Limited-Resource Areas

PURPOSE The most significant adverse risk factor for neuroblastoma (NB) is MYCN gene amplification, which strongly associates with high-risk disease. Fluorescent in situ hybridization (FISH) is considered the best method to evaluate MYCN gene status. However, it requires a laboratory that can perform highly complex testing, specialized personnel, and costly reagents. Herein, we aimed to investigate the feasibility of using immunohistochemistry (IHC) to detect MYCN protein expression in lieu of FISH, a strategy potentially useful in areas with limited resources. METHODS A pilot cohort of 78 patients with NB, including 34 of Middle Eastern descent (MED) who had a higher prevalence of MYCN gene amplification (44.11%) and 44 of North American descent (NAD), nine (20.45%) of whom had MYCN amplification, was evaluated with IHC for MYCN protein. Correlations of FISH results and protein expression are presented. RESULTS A positive correlation between MYCN gene amplification and protein expression by IHC was seen in 22 (91.66%) of the 24 MYCN-amplified NB cases—14 (93.33%) of 15 patients of MED and eight (88.88%) of nine patients of NAD. Agreement between negative FISH and negative IHC results was noted in 18 (94.73%) patients of MED and 34 (97.14%) patients of NAD. Two cases had weak protein expression but no gene amplification (MED: n = 1; 5.0%; NAD: n = 1; 2.9%). CONCLUSION An excellent overall correlation between MYCN gene status by FISH and MYCN protein expression by IHC was confirmed. MYCN IHC in NB with reflexing to FISH in equivocal cases is potentially useful in a limited-resource setting. Evaluation of effectiveness using a larger cohort and optimization to perform MYCN IHC manually is needed.