Epitope detection in monocytes (EDIM) for liquid biopsy including identification of GD2 in childhood neuroblastoma-a pilot study.

BACKGROUND: Neuroblastoma (NB) is the most common paediatric extracranial solid malignancy. We analysed the role of the epitope detection in monocytes (EDIM) technique for liquid biopsy in NB patients. METHODS: Tumour epitopes transketolase-like 1 (TKTL1), Apo10 (DNaseX) and GD2 were assessed: expression levels in seven NB tumour samples and five NB cell lines were analysed using RT-PCR and flow cytometry. LAN-1 cells were co-cultured with blood and assessed using EDIM. Peripheral blood macrophages of patients with neuroblastoma (n = 38) and healthy individuals (control group, n = 37) were labelled (CD14+/CD16+) and assessed for TKTL1, Apo10 and GD2 using the EDIM technology. RESULTS: mRNA expression of TKTL1 and DNaseX/Apo10 was elevated in 6/7 NB samples. Spike experiments showed upregulation of TKTL1, Apo10 and GD2 in LAN-1 cells following co-culturing with blood. TKTL1 and Apo10 were present in macrophages of 36/38 patients, and GD2 in 15/19 patients. The 37 control samples were all negative. EDIM expression scores of the three epitopes allowed differentiation between NB patients and healthy individuals. CONCLUSIONS: The EDIM test might serve as a non-invasive tool for liquid biopsy in children suffering from NB. Future studies are necessary for assessing risk stratification, tumour biology, treatment monitoring, and early detection of tumour relapses.

Epigallocatechin Gallate Inhibits Cell Growth and Hedgehog Signalling in Human Rhabdomyosarcoma Cell Lines.

BACKGROUND/AIM: Epigallocatechin gallate (EGCG), a major polyphenol of green tea, has been shown to inhibit cancer cell proliferation. In this study the effect of EGCG on cell metabolism and the human hedgehog signalling pathway (HH) in human rhabdomyosarcoma (RMS) cells was investigated. MATERIALS AND METHODS: Two human RMS cell lines (RD and RH30) were incubated with EGCG. To evaluate the effects of EGCG on RMS cells, cell viability, colony formation, cell migration, and alteration of genes related to the HH signalling pathway were investigated. RESULTS: EGCG showed cytostatic effects on RMS cells in a dose-dependent manner. Incubation with 25 µM EGCG resulted in a significant reduction of cell migration by 70% and downregulation of the HH pathway transcription factor GLI1. CONCLUSION: EGCG inhibits RMS cells in vitro by reducing cell proliferation and downregulating the HH signalling pathway. It may therefore be a promising agent in chemoresistant or advanced RMS in children.