Study of stem cell marker nestin and its correlation with vascular endothelial growth factor and microvascular density in ependymomas

MYCN immunohistochemistry as surrogate marker for MYCN-amplified spinal ependymomas

MYCN (master regulator of cell cycle entry and proliferative metabolism) gene amplification defines a molecular subgroup of spinal cord ependymomas that show high-grade morphology and aggressive behavior. Demonstration of MYCN amplification by DNA methylation or fluorescence-in situ hybridization (FISH) is required for diagnosis. We aimed to (i) assess prevalence and clinicopathological features of MYCN-amplified spinal ependymomas and (ii) evaluate utility of immunohistochemistry (IHC) for MYCN protein as a surrogate for molecular testing. A combined retrospective-prospective study spanning 8 years was designed during which all spinal cord ependymomas with adequate tissue were subjected to MYCN FISH and MYCN IHC. Among 77 spinal cord ependymomas included, MYCN amplification was identified in 4 samples from 3 patients (3/74, 4%) including two (1st and 2nd recurrences) from the same patient. All patients were adults (median age at diagnosis of 32 years) including two females and one male. The index tumors were located in thoracic (n = 2) and lumbar (n = 1) spinal cord. One of the female patients had neurofibromatosis type 2 (NF2). All four tumors showed anaplastic histology. Diffuse expression of MYCN protein was seen in all four MYCN-amplified samples but in none of the non-amplified cases, thus showing 100% concordance with FISH results. On follow-up, the NF2 patient developed widespread spinal dissemination while another developed recurrence proximal to the site of previous excision. To conclude, MYCN-amplified spinal ependymomas are rare tumors, accounting for ~ 4% of spinal cord ependymomas. Within the limitation of small sample size, MYCN IHC showed excellent concordance with MYCN gene amplification.

Human Patient-Derived Brain Tumor Models to Recapitulate Ependymoma Tumor Vasculature

Despite in vivo malignancy, ependymoma lacks cell culture models, thus limiting therapy development. Here, we used a tunable three-dimensional (3D) culture system to approximate the ependymoma microenvironment for recapitulating a patient's tumor in vitro. Our data showed that the inclusion of VEGF in serum-free, mixed neural and endothelial cell culture media supported the in vitro growth of all four ependymoma patient samples. The growth was driven by Nestin and Ki67 double-positive cells in a putative cancer stem cell niche, which was manifested as rosette-looking clusters in 2D and spheroids in 3D. The effects of extracellular matrix (ECM) such as collagen or Matrigel superseded that of the media conditions, with Matrigel resulting in the greater enrichment of Nestin-positive cells. When mixed with endothelial cells, the 3D co-culture models developed capillary networks resembling the in vivo ependymoma vasculature. The transcriptomic analysis of two patient cases demonstrated the separation of in vitro cultures by individual patients, with one patient's culture samples closely clustered with the primary tumor tissue. While VEGF was found to be necessary for preserving the transcriptomic features of in vitro cultures, the presence of endothelial cells shifted the gene's expression patterns, especially genes associated with ECM remodeling. The homeobox genes were mostly affected in the 3D in vitro models compared to the primary tumor tissue and between different 3D formats. These findings provide a basis for understanding the ependymoma microenvironment and enabling the further development of patient-derived in vitro ependymoma models for personalized medicine.

Cancer Stem Cells in Tumours of the Central Nervous System in Children: A Comprehensive Review

Cancer stem cells (CSCs) are a subgroup of cells found in various kinds of tumours with stem cell characteristics, such as self-renewal, induced differentiation, and tumourigenicity. The existence of CSCs is regarded as a major source of tumour recurrence, metastasis, and resistance to conventional chemotherapy and radiation treatment. Tumours of the central nervous system (CNS) are the most common solid tumours in children, which have many different types including highly malignant embryonal tumours and midline gliomas, and low-grade gliomas with favourable prognoses. Stem cells from the CNS tumours have been largely found and reported by researchers in the last decade and their roles in tumour biology have been deeply studied. However, the cross-talk of CSCs among different CNS tumour types and their clinical impacts have been rarely discussed. This article comprehensively reviews the achievements in research on CSCs in paediatric CNS tumours. Biological functions, diagnostic values, and therapeutic perspectives are reviewed in detail. Further investigations into CSCs are warranted to improve the clinical practice in treating children with CNS tumours.

Transcriptional factors targeting in cancer stem cells for tumor modulation

Cancer Stem Cells (CSCs) are now considered the primary "seeds" for the onset, development, metastasis, and recurrence of tumors. Despite therapeutic breakthroughs, cancer remains the leading cause of death worldwide. This is because the tumor microenvironment contains a key population of cells known as CSCs, which promote tumor aggression. CSCs are self-renewing cells that aid tumor recurrence by promoting tumor growth and persisting in patients after many traditional cancer treatments. According to reports, numerous transcription factors (TF) play a key role in maintaining CSC pluripotency and its self-renewal property. The understanding of the functions, structures, and interactional dynamics of these transcription factors with DNA has modified the hypothesis, paving the way for novel transcription factor-targeted therapies. These TFs, which are crucial and are required by cancer cells, play a vital function in the etiology of human cancer. Such CSC TFs will help with gene expression profiling, which provides crucial data for predicting the prognosis of patients. To overcome anti-cancer medication resistance and completely eradicate cancer, a potent therapy combining TFs-based CSC targets with traditional chemotherapy may be developed. In order to develop therapies that could eliminate CSCs, we here concentrated on the effect of TFs and other components of signalling pathways on cancer stemness.

The Role and Mechanism of the Vascular Endothelial Niche in Diseases: A Review

Vascular endothelial cells, forming the inner wall of the blood vessels, participate in the body’s pathological and physiological processes of immunity, tumors, and infection. In response to an external stimulus or internal pathological changes, vascular endothelial cells can reshape their microenvironment, forming a “niche”. Current research on the vascular endothelial niche is a rapidly growing field in vascular biology. Endothelial niches not only respond to stimulation by external information but are also decisive factors that act on neighboring tissues and circulating cells. Intervention through the vascular niche is meaningful for improving the treatment of several diseases. This review aimed to summarize reported diseases affected by endothelial niches and signal molecular alterations or release within endothelial niches. We look forward to contributing knowledge to increase the understanding the signaling and mechanisms of the vascular endothelial niche in multiple diseases.

Nestin-Expressing Cells in the Lung: The Bad and the Good Parts

Nestin is a member of the intermediate filament family, which is expressed in a variety of stem or progenitor cells as well as in several types of malignancies. Nestin might be involved in tissue homeostasis or repair, but its expression has also been associated with processes that lead to a poor prognosis in various types of cancer. In this article, we review the literature related to the effect of nestin expression in the lung. According to most of the reports in the literature, nestin expression in lung cancer leads to an aggressive phenotype and resistance to chemotherapy as well as radiation treatments due to the upregulation of phenomena such as cell proliferation, angiogenesis, and metastasis. Furthermore, nestin may be involved in the pathogenesis of some non-cancer-related lung diseases. On the other hand, evidence also indicates that nestin-positive cells may have a role in lung homeostasis and be capable of generating various types of lung tissues. More research is necessary to establish the true value of nestin expression as a prognostic factor and therapeutic target in lung cancer in addition to its usefulness in therapeutic approaches for pulmonary diseases.

Nestin Expression as a Diagnostic and Prognostic Marker in Colorectal Cancer and Other Tumors

Lung cancer, colon cancer, breast cancer, and prostate cancer are the leading causes of death in developed countries. Many cancers display non-specific signs in the early stage of the disease, thus making early diagnosis often difficult. We focused on nestin as a new biomarker of possible clinical importance in the early diagnosis and monitoring of cancer. The expression of nestin takes place at an early stage of neural differentiation, but no expression of the nestin gene can be revealed in normal, mature adult tissues. Nestin plays an important role in the development of the central nervous system and contributes to the organization and maintenance of cell shape. Nestin was found to be a marker of microvessel density, which in turn has proven to be a reliable prognostic factor for neoplastic malignancies in patients. Nestin expression correlates with an increased aggressiveness of tumor cells. The role of nestin in cancers of the colon and rectum, liver, central nervous system, lung cancer, breast cancer, melanoma, and other cancers has been reviewed in the literature. Associations between nestin expression and prognosis or drug-resistance may help in disease management. More research is needed to understand the molecular mechanisms of nestin expression and its role in possible targeted therapy.

Conventional and Advanced Magnetic Resonance Imaging Features of Supratentorial Extraventricular Ependymomas

OBJECTIVE

To describe the magnetic resonance imaging characteristics of supratentorial ependymomas.

METHODS

The magnetic resonance imaging and computed tomography imaging characteristics of 49 cases of supratentorial ependymomas were analyzed retrospectively. The location, size, degree of perilesional edema, gross appearance, computed tomography attenuation characteristics, T1 and T2 signal intensity characteristics, degree of diffusion restriction, presence of calcification, and hemorrhage were documented for each lesion. The intratumoral susceptibility scores (ITSS), apparent diffusion coefficient (ADC) values, relative cerebral blood volume, and choline/N-acetyl aspartate ratios were documented where available.

RESULTS

The frontal lobe was the most common location with a mean size of 6.37 × 4.8 cm. Severe perilesional edema was evident in 30%. Heterogenous, solid-cystic appearance was present in 96% lesions, with 95% of extraventricular lesions extending from pial surface to the ventricular margin. Calcification was seen in 55% of cases. The ITSS was 3 in 85.7% of lesions. The mean ADC value calculated was 600 × 10 mm/s. The mean relative cerebral blood volume on dynamic susceptibility contrast perfusion was 4.83. The mean choline/N-acetyl aspartate ratio was 5.87. Leptomeningeal dissemination was demonstrable in 5 lesions. Four lesions were abutting the dura with frank dural invasion in one. One patient presented with disseminated disease without evidence of a primary lesion.

CONCLUSIONS

A large lesion with relatively well-defined margins, heterogeneous solid cystic appearance, extending from the pial surface to the ventricular margin, presence of calcification, and ADC values approaching those of white matter should raise a suspicion of supratentorial ependymoma. High ITSS, MR perfusion parameters, and magnetic resonance spectroscopy characteristics are similar to those of other high-grade gliomas.

Expression and Clinical Significance of Translation Regulatory Long Non-Coding RNA 1 (TRERNA1) in Ependymomas

Long noncoding RNAs (lncRNA) have emerged as vital molecules governing epithelial-to-mesenchymal transition (EMT) in cancers. Translation regulatory RNA 1 (TRERNA1) is one such lncRNA known to enhance the transcriptional activity of the EMT-transcription factor, Snail. We have previously demonstrated differential upregulation of EMT-transcription factors and cadherin switching across various clinico-pathologic-molecular subclasses of ependymomas (EPN). With an aim to analyze the correlation between the expression of TRERNA1 in EPNs, we performed gene expression analysis for TRERNA1 on 75 Grade II/III EPNs and correlated with tumor site, C11orf95-RELA fusions, age, MIB-1 proliferative indices, and outcome wherever available. Upregulation of gene expression levels of TRERNA1 was seen in intracranial EPNs, with highest expression levels in pediatric posterior fossa EPNs. High TRERNA1 expression was found associated with higher proliferative indices (p = 0.034) and shorter progression free survival (p = 0.002). Our study, for the first time, demonstrates an association between TRERNA1 expressions and pediatric posterior fossa EPNs. Further in-vivo and in-vitro studies are required to confirm these findings and evaluate TRERNA1 as a novel biomarker and potential therapeutic target in childhood PF-EPNs.

Ultrastructural and histological changes in tibial remnant of ruptured anterior cruciate ligament stumps: a transmission electron microscopy and immunochemistry-based observational study

OBJECTIVES

Anterior cruciate ligament (ACL) rupture is a common injury and has a non-union rate of 40-100%. Important cellular events, such as fibroblast proliferation, angiogenesis and change in collagen fibril thickness in the ACL remnant, as described in other dense connective tissue, might have an implication in graft recovery following ACL reconstruction. Thus we conducted a study with an aim to characterize the ultrastructural and histological features of ruptured ACL tibial stump and correlate the same with the duration of injury.

MATERIALS AND METHODS

This was a prospective observational study in which 60 ruptured human ACLs were evaluated for collagen fibril thickness, blood vessel density (per mm²) and fibroblast density (per mm²) with the help of transmission electron microscopy, immunohistochemistry via CD34 antibody staining and light microscopy (H&E staining). The findings were correlated with duration of injury.

RESULTS

Fifty-four male and six female patients with a mean duration of the injury of 23.01 weeks (SD = 26.09; range 2-108 weeks) were included for the study and were divided on the basis of duration of injury as follows: Group I (≤ 6 weeks; N = 16), Group II (7-12 weeks; N = 18), Group III (13-20 weeks; N = 7), Group IV (21-50 weeks; N = 12), Group V (> 50 weeks; N = 7). A significant correlation was seen with blood vessel density (r = 0.303, p = 0.01) and fibroblast density (r = - 0.503, p = 0.001). Thickness of collagen fibril did not correlate with the duration of injury (r = 0.15, p = 0.23). The thickness of the collagen reached its peak after 50 weeks following injury, whereas highest density of blood vessel and fibroblast was seen at 12-20 weeks. Matched pair analysis revealed a significant decrease in collagen fibril thickness and an increase in fibroblast density at 7-12 weeks.

CONCLUSION

Following injury to ACL, the ruptured tibial stump undergoes a series of changes at the cellular level vis-à-vis changes in collagen fibril thickness, vascular density and fibroblast density that possibly suggest an intrinsic healing response. This further may have implications on the functional outcome following ACL reconstruction with remnant preservation.

LEVEL OF EVIDENCE

III.

Transcriptional co-expression regulatory network analysis for Snail and Slug identifies IL1R1, an inflammatory cytokine receptor, to be preferentially expressed in ST-EPN-RELA and PF-EPN-A molecular subgroups of intracranial ependymomas

Recent molecular subgrouping of ependymomas (EPN) by DNA methylation profiling has identified ST-EPN-RELA and PF-EPN-A subgroups to be associated with poor outcome. Snail/Slug are cardinal epithelial-to-mesenchymal transcription factors (EMT-TFs) and are overexpressed in several CNS tumors, including EPNs. A systematic analysis of gene-sets/modules co-expressed with Snail and Slug genes using published expression microarray dataset (GSE27279)identified 634 genes for Snail with enriched TGF-β, PPAR and PI3K signaling pathways, and 757 genes for Slug with enriched focal adhesion, ECM-receptor interaction and regulation of actin cytoskeleton related pathways. Of 37 genes commonly expressed with both Snail and Slug, IL1R1, a cytokine receptor of interleukin-1 receptor family, was positively correlated with Snail (r=0.43) and Slug (r=0.51), preferentially expressed in ST-EPN-RELA and PF-EPN-A molecular groups, and enriched for pathways related to inflammation, angiogenesis and glycolysis. IL1R1 expression was fairly specific to EPNs among various CNS tumors analyzed. It also showed significant positive correlation with EMT, stemness and MDSC (myeloid derived suppressor cell) markers. Our study reports IL1R1 as a poor prognostic marker associated with EMT-like phenotype and stemness in EPNs. Our findings emphasize the need to further examine and validate IL1R1 as a novel therapeutic target in aggressive subsets of intracranial EPNs.

Epithelial-to-mesenchymal transition-related transcription factors are up-regulated in ependymomas and correlate with a poor prognosis

Epithelial-to-mesenchymal transition (EMT) plays an important role in invasion and metastasis of various cancers including gliomas. EMT has also been linked to cancer stem cells and resistance to chemotherapy. An initial in-silico data mining in a published ependymoma (EPN) patient series (GSE21687) revealed up-regulation of EMT transcription factors in tumor samples. Furthermore, quantitative real-time polymerase chain reaction-based gene expression analysis of EMT transcription factors in 96 EPNs showed significant up-regulation of SNAI1, SNAI2, ZEB1, and TWIST1 as compared with normal brain, associated with up-regulation of CDH2/N-cadherin and down-regulation of CDH1/E-cadherin. Although this was observed in varying degrees in all clinicopathological-molecular subgroups of EPNs, it was most evident in supratentorial EPNs harboring fusions of RELA (v-rel avian reticuloendotheliosis viral oncogene homolog A) gene and in posterior fossa EPNs. Immunohistochemistry performed in 60 of the above cases corroborated with gene expression patterns, and immunopositivity for Snail, Slug, Zeb1, and Twist1 was observed in 80%, 80%, 81%, and 63% of all EPNs. Immunopositivity for N-cadherin and E-cadherin was observed in 76.6% and 2% of the cases, respectively. Univariate Cox regression analysis showed that low expression of CDH1/E-cadherin (P = .002) and high expression levels of CDH2/N-cadherin (P < .001), SNAI1/Snail (P = .023), SNAI2/Slug (P < .001), and ZEB1 (P < .001) were associated with shorter progression-free survival. Here, we report for the first time the existence of EMT-like phenotype in EPNs. These factors could represent new prognostic and therapeutic targets in EPN.

C11orf95-RELA fusions and upregulated NF-KB signalling characterise a subset of aggressive supratentorial ependymomas that express L1CAM and nestin

Ependymomas (EPN) show site specific genetic alterations and a recent DNA methylation profiling study identified nine molecular subgroups. C11orf95-RELA and YAP1 fusions characterise the RELA and YAP1 molecular subgroups, respectively, of supratentorial (ST)-EPNs. Current guidelines recommend molecular subgrouping over histological grade for accurate prognostication. Clinicopathological features of ST-EPNs in correlation with C11orf95-RELA and YAP1 fusions have been assessed in only few studies. We aimed to study these fusions in EPNs, and identify diagnostic and prognostic markers. qRT-PCR and Sanger Sequencing for the detection of C11orf95-RELA, YAP1-MAMLD1 and YAP1-FAM118B fusion transcripts, gene expression analysis for NFKB1, and immunohistochemistry for p53, MIB-1, nestin, VEGF, and L1CAM were performed. 88 EPNs (10-Grade I and 78-Grade II/III) from all sites were included. RELA fusions were unique to Grade II/III ST-EPNs, detected in 81.4% (22/27) and 18.5% (5/27) of pediatric and adult ST-EPNs respectively. ST-EPNs harbouring RELA fusions showed frequent grade III histology (81.5%), clear cell morphology (70.3%), upregulated NFKB1 expression, MIB-1 labelling indices (LI) ≥ 10% (77.8%), and immunopositivity for nestin (95.7%), VEGF (72%), L1CAM (79%), and p53 (64%). Presence of RELA fusions, L1CAM immunopositivity and MIB-1 LI ≥ 10% associated with poor outcome. L1CAM showed 81% concordance with RELA fusions. YAP1-MAMLD1 fusion was identified in a single RELA fusion negative adult anaplastic ST-EPN. RELA fusions are frequent in ST-EPNs and associate with poor outcome. L1CAM is a surrogate immunohistochemical marker. RELA fusion positive ST-EPNs strongly express nestin indicating increased stemness. Further evaluation of the interactions between NFKB and stem cell pathways is warranted.

Role of nestin expression in angiogenesis and breast cancer progression

Nestin is an intermediate filament protein and a stem cell marker expressed in several tumours. There is growing evidence of an association between the expression level of nestin and the pathogenesis of triple-negative breast cancer (TNBC). Nestin is also expressed in newly forming tumour vessels and is a valuable marker of ongoing angiogenesis. In this study, we aimed to evaluate the prognostic value of nestin expression in breast tumour cells and to determine whether this expression influences angiogenesis. Immunohistochemical (IHC) analyses were carried out on 124 cases of invasive ductal carcinoma (IDC) of the breast with a panel of murine monoclonal antibodies against nestin, CD31, CD34, SOX-18 and Ki‑67. We evaluated nestin expression in tumour and endothelial cells, Ki‑67 in tumour cells, and CD31, CD34 and SOX-18 in endothelial cells. Our results demonstrated that nestin expression in tumour cells correlated with the area and number of vessels expressing nestin, CD31, CD34 and SOX-18. We also found a positive correlation between nestin-expressing vessels and SOX-18-expressing vessels. Our results are consistent with those of previous studies, in which nestin expression in endothelial cells was shown to be strongly associated with triple-negative subtype, poorly differentiated G3 tumours, a higher proliferation index and a shorter overall survival. Nestin expression was also examined in human breast cancer cell lines (MCF-7, SK-BR-3, MDA‑MB‑231 and BO2 cells) representing a different level of tumour aggressiveness and reflecting histological grade. A higher nestin protein level was observed in more aggressive MDA‑MB‑231 and BO2 cells than in MCF-7 and SK-BR-3 cells.

Expression of nestin, CD133 and ABCG2 in relation to the clinical outcome in pediatric sarcomas

BACKGROUND

Nestin, CD133 and ABCG2 are recently discussed as putative markers, co-expression of which might determine a cancer stem cell (CSC) phenotype in sarcomas.

OBJECTIVE

Our study is focused on immunohistochemical analysis of nestin, CD133 and ABCG2 expression in rhabdomyosarcoma, Ewing sarcoma and osteosarcoma. Furthermore, we also analyzed the possible correlation of nestin, CD133 and ABCG2 expression levels with the patient outcome to identify potential prognostic values of these three putative CSC markers in the same cohorts.

METHODS

Using immunohistochemistry, expression of nestin, CD133 and ABCG2 was analyzed in 24 rhabdomyosarcoma, 22 Ewing sarcoma and 10 osteosarcoma tissue samples and expression levels of these markers were correlated with clinical outcome.

RESULTS

High nestin levels indicate poor prognosis in patients with Ewing sarcoma (P = 0.001), and high CD133 expression is associated with shorter survival in rhabdomyosarcoma patients (P = 0.002). In contrast, no significant relationship was found between ABCG2 expression and the clinical outcome.

CONCLUSIONS

Our analysis represents the first complex study of these three putative CSCs markers together in three different types of pediatric sarcomas and showed their possible prognostic values in these tumors.

Nestin as a marker of cancer stem cells

The crucial role of cancer stem cells (CSCs) in the pathology of malignant diseases has been extensively studied during the last decade. Nestin, a class VI intermediate filament protein, was originally detected in neural stem cells during development. Its expression has also been reported in different tissues under various pathological conditions. Specifically, nestin has been shown to be expressed in transformed cells of various human malignancies, and a correlation between its expression and the clinical course of some diseases has been proved. Furthermore, the coexpression of nestin with other stem cell markers was described as a CSC phenotype that was subsequently verified using tumorigenicity assays. The primary aim of this review is to summarize the recent findings regarding nestin expression in CSCs, its possible role in CSC phenotypes, particularly with respect to capacity for self-renewal, and its utility as a putative marker of CSCs.

Nestin-mediated cytoskeletal remodeling in endothelial cells: novel mechanistic insight into VEGF-induced cell migration in angiogenesis

Nestin is highly expressed in poorly differentiated and newly formed proliferating endothelial cells (ECs); however, the role of this protein in angiogenesis remains unknown. Additionally, the cytoskeleton and associated cytoskeleton-binding proteins mediate the migration of vascular ECs. Therefore, the aim of the present study was to determine whether VEGF regulates the cytoskeleton, as well as other associated proteins, to promote the migration of vascular ECs. The coexpression of nestin and CD31 during angiogenesis in alkali-burned rat corneas was examined via immunohistochemical analysis. Western blot analyses revealed that the exposure of human umbilical vein endothelial cells (HUVECs) to hypoxia promoted nestin expression in vitro. Additionally, nestin silencing via siRNA significantly inhibited many of the process associated with VEGF-induced angiogenesis, including tube formation and the migration and proliferation of HUVECs. Moreover, FITC-phalloidin labeling revealed that F-actin filaments were successfully organized into microfilaments in VEGF-treated cells, suggesting a network rearrangement accomplished via F-actin that contrasted with the uniform and loose actin filament network observed in the siRNA-nestin cells. The results of the present study highlight the key role played by nestin in activated HUVECs during angiogenesis. The inhibition of the ERK pathway suppressed the nestin expression induced by VEGF in the HUVECs. Therefore, our study provides the first evidence that nestin-mediated cytoskeleton remodeling in ECs occurs via filopodia formation along the cell edge, facilitating both filopodia localization and cell polarization and ultimately promoting HUVEC migration via VEGF induction, which may be associated with ERK pathway activation.