| 1. |
- Jamil, Seema, et al.
(författare)
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Tropism of the in situ growth from biopsies of childhood neuroectodermal tumors following transplantation into experimental teratoma
- 2014
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 134:7, s. 1630-1637
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Tidskriftsartikel (refereegranskat)abstract
- Experimental teratoma induced from human pluripotent stem cells with normal karyotype can be described as a failed embryonic process and includes besides advanced organoid development also large elements of tissue with a prolonged occurrence of immature neural components. Such immature components, although benign, exhibit strong morphological resemblance with tumors of embryonic neuroectodermal origin. Here, we demonstrate that biopsy material from childhood tumors of neural embryonic origin transplanted to mature experimental teratoma can show an exclusive preference for matching tissue. Tumor specimens from five children with; Supratentorial primitive neuroectodermal tumor (sPNET); Pilocytic astrocytoma of the brainstem; Classic medulloblastoma; peripheral primitive neuroectodermal tumor (pPNET) or neuroblastoma (NB), respectively, were transplanted. Analysis of up to 120 sections of each tumor revealed an engraftment for three of the transplanted tumors: pPNET, sPNET, and NB, with a protruding growth from the latter two that were selected for detailed examination. The histology revealed a strict tropism with a non-random integration into what morphologically appeared as matched embryonic microenvironment recuperating the patient tumor histology. The findings suggest specific advantages over xenotransplantation and lead us to propose that transplantation to the human embryonic microenvironment in experimental teratoma can be a well-needed complement for preclinical in vivo studies of childhood neuroectodermal tumors. What's new? The ability to better replicate the human neoplastic niche in vivo could help improve the predictive reliability of animal models. To that end, this study shows that biopsies from childhood neuroectodermal tumors are able to engraft into specific embryonic components of human experimental teratoma. Histological examination revealed a strict tropism of a neuroblastoma as well as a supratentorial primitive neuroectodermal tumor, showing nonrandom integration into morphologically identifiable tissues. The study opens new possibilities for the analysis of growth-promoting environmental factors and for investigating novel therapies targeted to the microenvironment of childhood neuroectodermal tumors.
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| 2. |
- Gertow, Karin, et al.
(författare)
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Early Events in Xenograft Development from the Human Embryonic Stem Cell Line HS181-Resemblance with an Initial Multiple Epiblast Formation
- 2011
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:11, s. e27741-
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Tidskriftsartikel (refereegranskat)abstract
- Xenografting is widely used for assessing in vivo pluripotency of human stem cell populations. Here, we report on early to late events in the development of mature experimental teratoma from a well-characterized human embryonic stem cell (HESC) line, HS181. The results show an embryonic process, increasingly chaotic. Active proliferation of the stem cell derived cellular progeny was detected already at day 5, and characterized by the appearance of multiple sites of engraftment, with structures of single or pseudostratified columnar epithelium surrounding small cavities. The striking histological resemblance to developing embryonic ectoderm, and the formation of epiblast-like structures was supported by the expression of the markers OCT4, NANOG, SSEA-4 and KLF4, but a lack of REX1. The early neural marker NESTIN was uniformly expressed, while markers linked to gastrulation, such as BMP-4, NODAL or BRACHYURY were not detected. Thus, observations on day 5 indicated differentiation comparable to the most early transient cell populations in human post implantation development. Confirming and expanding on previous findings from HS181 xenografts, these early events were followed by an increasingly chaotic development, incorporated in the formation of a benign teratoma with complex embryonic components. In the mature HS181 teratomas not all types of organs/tissues were detected, indicating a restricted differentiation, and a lack of adequate spatial developmental cues during the further teratoma formation. Uniquely, a kinetic alignment of rare complex structures was made to human embryos at diagnosed gestation stages, showing minor kinetic deviations between HS181 teratoma and the human counterpart.
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| 3. |
- Hedborg, Fredrik, et al.
(författare)
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Differentiation in Neuroblastoma : Diffusion-Limited Hypoxia Induces Neuro-Endocrine Secretory Protein 55 and Other Markers of a Chromaffin Phenotype
- 2010
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 5:9, s. e12825-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Neuroblastoma is a childhood malignancy of sympathetic embryonal origin. A high potential for differentiation is a hallmark of neuroblastoma cells. We have previously presented data to suggest that in situ differentiation in tumors frequently proceeds along the chromaffin lineage and that decreased oxygen ( hypoxia) plays a role in this. Here we explore the utility of Neuro-Endocrine Secretory Protein 55 ( NESP55), a novel member of the chromogranin family, as a marker for this process. Methodology/Principal Findings: Immunohistochemical analyses and in situ hybridizations were performed on human fetal tissues, mouse xenografts of human neuroblastoma cell lines, and on specimens of human neuroblastoma/ganglioneuroma. Effects of anaerobic exposure on gene expression by cultured neuroblastoma cells was analyzed with quantitative real-time PCR. Fetal sympathetic nervous system expression of NESP55 was shown to be specific for chromaffin cell types. In experimental and clinical neuroblastoma NESP55 immunoreactivity was specific for regions of chronic hypoxia. NESP55 expression also correlated strikingly with morphological evidence of differentiation and with other chromaffin-specific patterns of gene expression, including IGF2 and HIF2 alpha. Anaerobic culture of five neuroblastoma cell lines resulted in an 18.9-fold mean up-regulation of NESP55. Conclusions/Significance: The data confirms that chronic tumor hypoxia is a key microenvironmental factor for neuroblastoma cell differentiation, causing induction of chromaffin features and NESP55 provides a reliable marker for this neuronal to neuroendocrine transition. The hypoxia-induced phenotype is the predominant form of differentiation in stroma-poor tumors, while in stroma-rich tumors the chromaffin phenotype coexists with ganglion cell-like differentiation. The findings provide new insights into the biological diversity which is a striking feature of this group of tumors.
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| 4. |
- Holmquist Mengelbier, Linda, et al.
(författare)
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Deletions of 16q in Wilms Tumors Localize to Blastemal-Anaplastic Cells and Are Associated with Reduced Expression of the IRXB Renal Tubulogenesis Gene Cluster.
- 2010
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Ingår i: American Journal of Pathology. - : Elsevier BV. - 1525-2191 .- 0002-9440. ; 177:5, s. 2609-2621
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Tidskriftsartikel (refereegranskat)abstract
- Wilms tumor is the most common pediatric renal neoplasm, but few molecular prognostic markers have been identified for this tumor. Somatic deletion in the long arm of chromosome 16 (16q) is known to predict a less favorable outcome in Wilms tumor, but the underlying molecular mechanisms are not known. We show that 16q deletions are typically confined to immature anaplastic-blastic tumor elements, while deletions are absent in maturing tumor components. The smallest region of deletion overlap mapped to a 1.8-Mb segment containing the IRXB gene cluster including IRX3, IRX5, and IRX6, of which IRX3 is a recently identified regulator of tubular maturation during nephrogenesis. Tumors with 16q deletion showed a lower overall mRNA expression of IRXB genes, and 16q-deleted tumor cells failed to express IRX3 while it was expressed in differentiating tubular tumor elements with intact 16q. Consistent with a role for IRX3 in tubular differentiation, gene sets linked to Notch signaling, Rho signaling, and ion channel activity were enriched in tumors with high IRX3 expression, while WTs with low expression were enriched for gene sets linked to cell cycle progression. Low mRNA levels of IRXB genes were associated with diffuse anaplasia, high-stage disease, and death. A disturbed balance between tubular differentiation and self-renewal of anaplastic-blastic elements may thus be one mechanism linking 16q deletion to adverse outcome in Wilms tumor.
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| 5. |
- Ljungman, Gustaf, et al.
(författare)
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Incidence and Survival Analyses in Children with Solid Tumours Diagnosed in Sweden 1983-2007.
- 2011
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Ingår i: Acta paediatrica. - : Wiley. - 1651-2227 .- 0803-5253. ; 100:5, s. 750-757
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Tidskriftsartikel (refereegranskat)abstract
- Aim: Solid tumours constitute 40% of childhood malignancies. The Swedish Childhood Cancer Registry is population-based and includes all children with cancer reported from the six paediatric oncology centres in Sweden. The aim was to investigate incidence and survival. Methods: We used the new WHO ICCC-3 for reclassification of the patients. Incidence and survival analyses were performed in the study population. Results: 2 487 children (< 15 years) were diagnosed with solid tumours in Sweden 1983 - 2007. The distribution of diagnoses was similar to that reported in other studies. The annual incidence was 65.3/million children. The survival rates at 10 years follow up have improved significantly when comparing the two time periods 1983-95 and 1995-2007 (76 vs. 82%; p<0.01). Conclusions: The mean annual incidence of solid tumours in children was 65.3/ million and has been stable during the study period. Survival rates for solid tumours at 5, 10 and 20 years follow up were 80, 79 and 76%, respectively.
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| 6. |
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| 7. |
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| 8. |
- Ljungman, Gustaf, et al.
(författare)
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Incidence and survival analyses in children with solid tumours diagnosed in Sweden between 1983 and 2007
- 2011
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Ingår i: Acta Paediatrica. - : Wiley. - 0803-5253 .- 1651-2227. ; 100:5, s. 750-757
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Tidskriftsartikel (refereegranskat)abstract
- Aim: Solid tumours constitute 40% of childhood malignancies. The Swedish Childhood Cancer Registry is population based and includes all children with cancer reported from the six paediatric oncology centres in Sweden. The aim was to investigate incidence and survival. Methods: We used the new WHO ICCC-3 for reclassification of the patients. Incidence and survival analyses were performed in the study population. Results: Two thousand four hundred and eighty-seven children (< 15 years) were diagnosed with solid tumours in Sweden between 1983 and 2007. The distribution of diagnoses was similar to that reported in other studies. The annual incidence was 65.3 per million children. The survival rates at 10 years of follow-up have improved significantly when comparing the two time periods, 1983-1995 and 1995-2007 (76 vs. 82%; p < 0.01). Conclusions: The mean annual incidence of solid tumours in children was 65.3/million and has been stable during the study period. Survival rates for solid tumours at 5, 10 and 20 years follow-up were 80, 79 and 76%, respectively.
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| 9. |
- Sehic, Daniel, et al.
(författare)
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SIX1 protein expression selectively identifies blastemal elements in Wilms tumor.
- 2012
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Ingår i: Pediatric Blood & Cancer. - : Wiley. - 1545-5017 .- 1545-5009. ; 59:1, s. 62-68
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Wilms tumor (WT) is the most common renal neoplasm in children. Histologically, most WTs consist of three tissue elements: blastema, epithelium, and stroma. Some cases also show diffuse or focal anaplastic features. Previous studies have shown that a predominance of blastemal cells in post-chemotherapy WT specimens is associated with a poor clinical course. However, there is currently no molecular marker for blastemal cells, and risk stratification for post-nephrectomy treatment is therefore often based on clinico-histological parameters alone. PROCEDURE: In the present study, three public gene expression microarray datasets, including 82 WTs and 8 normal fetal kidneys, were used to establish a consensus gene expression profile of WT. By bioinformatic analyses, 17 genes overexpressed in WT compared to fetal kidney were then selected for evaluation of their protein expression in WT cell lines and in the different histological components in paraffin-embedded WT tissue sections by immunofluorescence. RESULTS: Most of the evaluated proteins were expressed in all three common histological components. A prominent exception was SIX1, being expressed predominantly in blastemal elements in 24/25 pediatric cases containing blastema. Anaplastic elements exhibited highly variable SIX1-positivity. The SIX2 protein, known to be co-expressed with SIX1 during nephrogenesis, only exhibited blastemal-predominant expression in half of the SIX2 evaluated cases. CONCLUSIONS: Genes highly expressed in WT compared to fetal kidney are generally overexpressed in all of the three common WT tissue elements. An exception is the predominant expression of SIX1 in blastemal cells, hereby identifying this protein as a candidate marker for blastema. Pediatr Blood Cancer © 2011 Wiley Periodicals, Inc.
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