Detecting circulating tumor cells (CTCs) has proven valuable for evaluating the prognosis of cancer patients and for studying the mechanisms of treatment resistance. Owing to the lack of universal and specific tumor markers for neuroblastoma (NB), in this prospective study, we adopted an EpCAM-independent method to detect CTCs in the peripheral blood of NB patients. We used an EpCAM-independent assay to delete leukocytes and to enrich the CTCs. CTCs were identified by immunostaining of CD45, DAPI and DNA fluorescence in situ hybridization (FISH) of the centromere of chromosome 8 probe (CEP8). Cells that were DAPI+/CD45-/CEP8 ≥ 3 were considered CTCs. We collected peripheral blood from 28 NB patients as well as clinical and follow-up data. The number of CTCs among the different risk groups were significantly different (p = .0208, Kruskal-Wallis test). Patients with metastasis had more CTCs than those without metastasis (p < .0001, Mann-Whitney test). Patients with ≥3 CTCs per 4 ml of peripheral blood had an increased likelihood of having metastasis (sensitivity, 88.89%; specificity, 78.59%), and patients with ≥10 CTCs per 4 ml of peripheral blood had poorer overall survival. The EpCAM-independent assay along with immunostaining-FISH (i-FISH) described here can detect CTCs in patients with NB at a high sensitivity and may have clinical value for prognosis evaluation and diagnosing metastasis when imaging data are ambiguous.

Background: Hirschsprung's disease (HSCR) is a relatively common congenital disability. Accumulating extracellular matrix (ECM) prompts intestinal fibrosis remodelling in the aganglionic segments of HSCR. The contributions of various cellular subsets in the fibrogenesis of HSCR segments are poorly understood.Methods: Single‐cell transcriptomics from 8 aganglionic segments and 5 normal segments of 7 HSCR subjects and 26 healthy segments of seven healthy donors were analysed. Fibrotic phenotype and alterations were explored using differential expression analysis and single‐cell trajectory analysis. Fibrosis‐related transcription factors were inferred through single‐cell regulatory network inference. Bulk transcriptomic data, proteomic data, immunohistochemistry (IHC) and real‐time polymerase chain reaction were used to validate the alterations in the HSCR intestine.Results: Various collagen, fibronectin and laminin protein‐coding genes expression were up‐regulated in the stromal and glial cells of the HSCR intestine. The number of fibroblasts and myofibroblasts in the aganglionic segments increased, and more myofibroblasts were activated at an earlier stage in HSCR segments, which infers that there is an intestinal fibrosis phenotype in HSCR segments. The fibrotic regulators POSTN, ANXA1 and HSP70 were highly expressed in the ECM‐related cellular subsets in the transitional segments and aganglionic segments. The transcription factor regulatory network revealed that fibrosis‐related and megacolon‐related NR2F1 in the fibroblasts and glial subsets was up‐regulated in the aganglionic segment.Conclusions: This work identifies intestinal fibrosis and related regulators in aganglionic segments of HSCR; hence, anti‐fibrotic therapy may be considered to prevent HSCR‐associated enterocolitis (HAEC), relieve intestinal stricture and improve cell therapy.