Central nervous system recurrence of desmoplastic small round cell tumor following aggressive multimodal therapy: A case report

Desmoplastic Small Round Cell Tumor Presenting as an Intra/Extracranial Mass

Desmoplastic small round cell tumors (DSRCTs) are highly malignant tumors, with distinct reciprocal chromosome translocation (11;22)(p13;q12). Intracranial metastasis is a very rare complication of this tumor, with only a few cases reported in the literature. To our knowledge, this is the only case presenting an extracranial extension of intracranial metastasis of DSRCT. A 33-year-old man was diagnosed with DSRCT in the pelvic cavity. He presented with a scalp lump and right-sided weakness. A biopsy showed metastasis from DSRCT. Metastatic DSRCT to the brain is extremely rare. Surgical resection followed by adjuvant treatment, including chemotherapy and radiation, is indicated as it has a poor prognosis. Moreover, aggressive treatment is warranted to prevent progression and relapse.

Desmoplastic Small Round Cell Tumor With Ascending Intraspinal Metastasis at Recurrence: Case Report and Review of the Literature

BACKGROUND

Desmoplastic small round cell tumor (DSRCT) is a rare and aggressive malignancy commonly involving the abdomen and/or pelvic peritoneum. Despite aggressive therapy, the prognosis remains poor. Central nervous system relapse is rare in abdominal/pelvic primary DSRCT.

OBSERVATION

We report a case of a 10-year-old female with a large pelvic DSRCT and involvement of the rectosigmoid colon and liver. Following treatment with chemotherapy, and cytoreductive surgery with hyperthermic intraperitoneal chemotherapy an initial response was noted. With progressive lower limb weakness, recurrence with perineural invasion in the lumbosacral nerve root involving the conus was noted 2.5 years from diagnosis. Cerebrospinal fluid showed tumor cells with a molecular confirmation.

CONCLUSIONS

Perineural invasion and ascending paralysis secondary to primary abdominal DSRCT has not been previously reported to our knowledge. We recommend a high index of suspicion for early and accurate diagnosis of this rare presentation.

Comprehensive Molecular Profiling of Desmoplastic Small Round Cell Tumor

Desmoplastic small round cell tumor (DSRCT) is characterized by the EWSR1-WT1 t(11;22) (p13:q12) translocation. Few additional putative drivers have been identified, and research has suffered from a lack of model systems. Next-generation sequencing (NGS) data from 68 matched tumor-normal samples, whole-genome sequencing data from 10 samples, transcriptomic and affymetrix array data, and a bank of DSRCT patient-derived xenograft (PDX) are presented. EWSR1-WT1 fusions were noted to be simple, balanced events. Recurrent mutations were uncommon, but were noted in TERT (3%), ARID1A (6%), HRAS (5%), and TP53 (3%), and recurrent loss of heterozygosity (LOH) at 11p, 11q, and 16q was identified in 18%, 22%, and 34% of samples, respectively. Comparison of tumor-normal matched versus unmatched analysis suggests overcalling of somatic mutations in prior publications of DSRCT NGS data. Alterations in fibroblast growth factor receptor 4 (FGFR4) were identified in 5 of 68 (7%) of tumor samples, whereas differential overexpression of FGFR4 was confirmed orthogonally using 2 platforms. PDX models harbored the pathognomic EWSR1-WT1 fusion and were highly representative of corresponding tumors. Our analyses confirm DSRCT as a genomically quiet cancer defined by the balanced translocation, t(11;22)(p13:q12), characterized by a paucity of secondary mutations but a significant number of copy number alterations. Against this genomically quiet background, recurrent activating alterations of FGFR4 stood out, and suggest that this receptor tyrosine kinase, also noted to be highly expressed in DSRCT, should be further investigated. Future studies of DSRCT biology and preclinical therapeutic strategies should benefit from the PDX models characterized in this study. IMPLICATIONS: These data describe the general quiescence of the desmoplastic small round cell tumor (DSRCT) genome, present the first available bank of DSRCT model systems, and nominate FGFR4 as a key receptor tyrosine kinase in DSRCT, based on high expression, recurrent amplification, and recurrent activating mutations.

Olaparib and temozolomide in desmoplastic small round cell tumors: a promising combination in vitro and in vivo

Purpose

Desmoplastic small round cell tumors (DSRCTs) are highly malignant and very rare soft tissue sarcomas with a high unmet need for new therapeutic options. Therefore, we examined poly(ADP-ribose) polymerase 1 (PARP1) and Schlafen-11 (SLFN11) expression in DSRCT tumor tissue and the combination of PARP inhibitor olaparib with the alkylating agent temozolomide (TMZ) in a preclinical DSRCT model.

Methods

PARP1 and SLFN11 have been described as predictive biomarkers for response to PARP inhibition. Expression of PARP1 and SLFN11 was assessed in 16 and 12 DSRCT tumor tissue samples, respectively. Effects of single-agent olaparib, and olaparib and TMZ combination treatment were examined using the preclinical JN-DSRCT-1 model. In vitro, single-agent and combination treatment effects on cell viability, the cell cycle, DNA damage and apoptosis were examined. Olaparib and TMZ combination treatment was also assessed in vivo.

Results

PARP1 and SLFN11 expression was observed in 100% and 92% of DSRCT tumor tissues, respectively. Olaparib treatment reduced cell viability and cell migration in a dose-dependent manner in vitro. Drug synergy between olaparib and TMZ was observed in vitro and in vivo. Combination treatment led to a cell-cycle arrest and induction of DNA damage and apoptosis, even when combined at low dosages.

Conclusion

We show high PARP1 and SLFN11 expression in DSRCT tumor material and antitumor effects following olaparib and TMZ combination treatment in a preclinical DSRCT model. This suggests that olaparib and TMZ combination treatment could be a potential treatment option for DSRCTs.

Electronic supplementary material

The online version of this article (10.1007/s00432-020-03211-z) contains supplementary material, which is available to authorized users.

Mapping theme trends and knowledge structures for human neural stem cells: a quantitative and co-word biclustering analysis for the 2013-2018 period

Neural stem cells, which are capable of multi-potential differentiation and self-renewal, have recently been shown to have clinical potential for repairing central nervous system tissue damage. However, the theme trends and knowledge structures for human neural stem cells have not yet been studied bibliometrically. In this study, we retrieved 2742 articles from the PubMed database from 2013 to 2018 using "Neural Stem Cells" as the retrieval word. Co-word analysis was conducted to statistically quantify the characteristics and popular themes of human neural stem cell-related studies. Bibliographic data matrices were generated with the Bibliographic Item Co-Occurrence Matrix Builder. We identified 78 high-frequency Medical Subject Heading (MeSH) terms. A visual matrix was built with the repeated bisection method in gCLUTO software. A social network analysis network was generated with Ucinet 6.0 software and GraphPad Prism 5 software. The analyses demonstrated that in the 6-year period, hot topics were clustered into five categories. As suggested by the constructed strategic diagram, studies related to cytology and physiology were well-developed, whereas those related to neural stem cell applications, tissue engineering, metabolism and cell signaling, and neural stem cell pathology and virology remained immature. Neural stem cell therapy for stroke and Parkinson's disease, the genetics of microRNAs and brain neoplasms, as well as neuroprotective agents, Zika virus, Notch receptor, neural crest and embryonic stem cells were identified as emerging hot spots. These undeveloped themes and popular topics are potential points of focus for new studies on human neural stem cells.

Expression profiles of exosomal miRNAs isolated from plasma of patients with desmoplastic small round cell tumor

AIM

Desmoplastic small round cell tumor (DSRCT) is a rare, aggressive mesenchymal tumor, lacking biomarkers for diagnosis, treatment stratification and prognosis. We investigated the exosomal miRNA profile in plasma samples collected from DSRCT patients, evaluating their potential as circulating biomarkers for this tumor.

PATIENTS & METHODS

We isolated exosomes from plasma of three DSRCT adolescents and four age-matched healthy controls; expression of circulating miRNAs was quantified by qPCR.

RESULTS

We identified 55 miRNAs significantly modulated compared with healthy controls. Among these miRNAs, 14 were highly dysregulated in at least one patient and 5 were expressed in all patients.

CONCLUSION

To our knowledge, this is the first report describing exosomal miRNAs as promising biomarkers to characterize disease status in DSRCT patients.

L-MYC Expression Maintains Self-Renewal and Prolongs Multipotency of Primary Human Neural Stem Cells

Pre-clinical studies indicate that neural stem cells (NSCs) can limit or reverse CNS damage through direct cell replacement, promotion of regeneration, or delivery of therapeutic agents. Immortalized NSC lines are in growing demand due to the inherent limitations of adult patient-derived NSCs, including availability, expandability, potential for genetic modifications, and costs. Here, we describe the generation and characterization of a new human fetal NSC line, immortalized by transduction with L-MYC (LM-NSC008) that in vitro displays both self-renewal and multipotent differentiation into neurons, oligodendrocytes, and astrocytes. These LM-NSC008 cells were non-tumorigenic in vivo, and migrated to orthotopic glioma xenografts in immunodeficient mice. When administered intranasally, LM-NSC008 distributed specifically to sites of traumatic brain injury (TBI). These data support the therapeutic development of immortalized LM-NSC008 cells for allogeneic use in TBI and other CNS diseases.

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The generation of a new human fetal L-MYC-immortalized NSC line is described

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These NSCs display self-renewal and can differentiate into neurons and glia

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The NSCs can target glioma xenografts and sites of traumatic brain injury in mice

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This NSC line may become applicable in therapy of various CNS diseases