VEGF-C, VEGF-D and VEGFR-3 expression in peripheral neuroblastic tumours

Pediatric reference values of VEGF-D derived from a German population-based cohort of healthy children

BACKGROUND

Vascular endothelial growth factor D (VEGF-D) is a growth-factor involved in the development of blood vessels and lymphatics in tissues all over the human body. Interestingly, VEGF-D serum levels are increased in certain tumor entities. For tuberous sclerosis complex (TSC), a rare genetic disease associated with (benign) tumor growth, VEGF-D is already implemented as a diagnostic and therapeutic biomarker to monitor onset and progress of lymphangioleiomyomatosis (LAM), one of the noncancerous tumor manifestations in mainly female adult TSC patients. To date only adult VEGF-D serum cut off values are established and used as a diagnostic tool in LAM. Neither cut off nor pediatric reference values for VEGF-D serum levels are known, our study aims to provide reliable pediatric VEGF-D results in samples from healthy children and adolescents.

METHODS

We analyzed 2003 samples provided by healthy children aged 0.25-18 years participating in the prospective longitudinal population-based cohort study "LIFE Child" in Leipzig, Germany. Serum VEGF-D levels were measured by enzyme-linked immunoassay.

RESULTS

VEGF-D levels in healthy children and adolescents show age-and gender specific variations. We showed a significant difference between girls and boys in post pubertal VEGF-D levels. Especially the fact, that girls showed higher VEGF-D levels with advancing stages of puberty is underlining the importance of estrogen metabolism in context of VEGF-D mediated cell proliferation, angiogenesis and associated disease mechanisms.

CONCLUSION

Knowing VEGF-D levels in growing healthy young children and adolescents could help to recognize early disease progression of LAM in individuals at risk especially young women suffering from TSC. Further studies are needed on VEGF-D serum levels in children, especially the impact of estrogen metabolism on VEGF-D should be investigated further.

Lymphatic vessel: origin, heterogeneity, biological functions, and therapeutic targets

Lymphatic vessels, comprising the secondary circulatory system in human body, play a multifaceted role in maintaining homeostasis among various tissues and organs. They are tasked with a serious of responsibilities, including the regulation of lymph absorption and transport, the orchestration of immune surveillance and responses. Lymphatic vessel development undergoes a series of sophisticated regulatory signaling pathways governing heterogeneous-origin cell populations stepwise to assemble into the highly specialized lymphatic vessel networks. Lymphangiogenesis, as defined by new lymphatic vessels sprouting from preexisting lymphatic vessels/embryonic veins, is the main developmental mechanism underlying the formation and expansion of lymphatic vessel networks in an embryo. However, abnormal lymphangiogenesis could be observed in many pathological conditions and has a close relationship with the development and progression of various diseases. Mechanistic studies have revealed a set of lymphangiogenic factors and cascades that may serve as the potential targets for regulating abnormal lymphangiogenesis, to further modulate the progression of diseases. Actually, an increasing number of clinical trials have demonstrated the promising interventions and showed the feasibility of currently available treatments for future clinical translation. Targeting lymphangiogenic promoters or inhibitors not only directly regulates abnormal lymphangiogenesis, but improves the efficacy of diverse treatments. In conclusion, we present a comprehensive overview of lymphatic vessel development and physiological functions, and describe the critical involvement of abnormal lymphangiogenesis in multiple diseases. Moreover, we summarize the targeting therapeutic values of abnormal lymphangiogenesis, providing novel perspectives for treatment strategy of multiple human diseases.

MYCN Impact on High-Risk Neuroblastoma: From Diagnosis and Prognosis to Targeted Treatment

Among childhood cancers, neuroblastoma is the most diffuse solid tumor and the deadliest in children. While to date, the pathology has become progressively manageable with a significant increase in 5-year survival for its less aggressive form, high-risk neuroblastoma (HR-NB) remains a major issue with poor outcome and little survivability of patients. The staging system has also been improved to better fit patient needs and to administer therapies in a more focused manner in consideration of pathology features. New and improved therapies have been developed; nevertheless, low efficacy and high toxicity remain a staple feature of current high-risk neuroblastoma treatment. For this reason, more specific procedures are required, and new therapeutic targets are also needed for a precise medicine approach. In this scenario, MYCN is certainly one of the most interesting targets. Indeed, MYCN is one of the most relevant hallmarks of HR-NB, and many studies has been carried out in recent years to discover potent and specific inhibitors to block its activities and any related oncogenic function. N-Myc protein has been considered an undruggable target for a long time. Thus, many new indirect and direct approaches have been discovered and preclinically evaluated for the interaction with MYCN and its pathways; a few of the most promising approaches are nearing clinical application for the investigation in HR-NB.

Targeting the Tumor Microenvironment in Neuroblastoma: Recent Advances and Future Directions

Neuroblastoma (NB) is the most common pediatric tumor malignancy that originates from the neural crest and accounts for more than 15% of all the childhood deaths from cancer. The neuroblastoma cancer research has long been focused on the role of MYCN oncogene amplification and the contribution of other genetic alterations in the progression of this malignancy. However, it is now widely accepted that, not only tumor cells, but the components of tumor microenvironment (TME), including extracellular matrix, stromal cells and immune cells, also contribute to tumor progression in neuroblastoma. The complexity of different components of tumor stroma and their resemblance with surrounding normal tissues pose huge challenges for therapies targeting tumor microenvironment in NB. Hence, the detailed understanding of the composition of the TME of NB is crucial to improve existing and future potential immunotherapeutic approaches against this childhood cancer. In this review article, I will discuss different components of the TME of NB and the recent advances in the strategies, which are used to target the tumor microenvironment in neuroblastoma.

The immunohistochemical landscape of the VEGF family and its receptors in glioblastomas

Background

Angiogenesis is one of the hallmarks of cancer. This complex mechanism of tumor progression provides tumors cells with essential nutrients. There have been a limited number of investigations of markers of angiogenesis in Glioblastomas (GBMs), and most previous studies have focused on VEGF-A. Recent evidence suggests that there is a complex lymphatic system in central nervous system (CNS), which suggests VEGF-C and VEGF–D as interesting biomarker candidates. This study was designed to evaluate the expressions of VEGF-A, −C, −D and their co-receptors, VEGFR-1, VEGFR-2, and VEGFR-3 by immunohistochemistry (IHC) using a series of GBMs. In addition, we evaluate any putative correlations between IHC expression levels of VEGF and clinical data of patients.

Methods

Tumor samples of 70 GBM patients (64 isocitrate dehydrogenase-1 wildtype (wtIDH-1) and 6 mutant (mutIDH-1)) were assessed by IHC using tissue microarray platforms for VEGF subunits and their co-receptors. The medical records were reviewed for clinical and therapeutic data.

Results

All VEGF subunits and receptors were highly expressed in GBMs: 57 out of 62 (91.9%), 53 out of 56 (94.6%) and 55 out of 63 cases (87.3%) showed VEGF-A, VEGF-C and -D imunoexpression, respectively. Interestingly, we had found both nuclear and cytoplasmic localization of VEGF-C staining in GBM tumor cells. The frequency of immunoexpression of VEGF receptors was the following: VEGFR-1, 65 out of 66 cases (98.5%); VEGFR-2, 63 out of 64 cases (98.4%); VEGFR-3, 49 out of 50 cases (90.0%). There were no significant differences in the patient overall survival (OS) related to the VEGF staining. A weak and monotonous correlation was observed between VEGF and its cognate receptors. The pattern of VEGF IHC was found to be similar when GBM mutIDH-1 subtypes were compared to wtIDH-1.

Conclusion

Both VEGF-C and –D, together with their receptors, were found to be overexpressed in the majority GBMs, and the IHC expression levels did not correlate with OS or IDH status. To understand the significance of the interactions and increased expression of VEGF-C, VEGF-D, VEGFR-2, and VEGFR-3 axis in GBM requires more extensive studies. Also, functional assays using a larger series of GBM is also necessary to better address the biological meaning of nuclear VEGF-C expression in tumor cells.

Vessel adherent growth represents a major challenge in the surgical resection of neuroblastoma and Is associated with adverse outcome

PURPOSE

Neuroblastoma (NB) is the most common extracranial, solid tumor in childhood, with a peak incidence in children under 6 years of age. Due to its variable course of disease, which ranges from spontaneous regression to metastatic spread, NB still represents a significant therapeutic challenge. Strikingly, a certain number of NBs intraoperatively show vessel adhesion and/or infiltrative growth, which is often not visible in pre-operative imaging. We proposed the term unexpected vessel infiltration of NB (UVIN) to denote this phenomenon. UVIN represents a major surgical challenge.

METHODS

In this study, we determined frequency and clinical relevance of UVIN in a cohort of 100 NB-patients with subsequent correlation to several unfavorable characteristics of disease. RNA expression levels of MYCN and its co-regulated antisense transcript MYCNOS to identify markers was measured by PCR.

RESULTS

We found UVIN to be present in 34% of cases and significantly correlated with incomplete resection, MYCN amplification, complications, neoadjuvant therapy, tumor grade and MYCNOS expression levels. MYCN expression levels showed no significant results with UVIN.

CONCLUSION

Collectively, our data show that UVIN represents a frequent surgical problem associated with a poor outcome in NB patients. MYCN and MYCNOS seem to be no appropriate markers for UVIN.

TYPE OF STUDY

Prognosis study.

LEVEL OF EVIDENCE

Level III.

Neuroblastoma in children: Update on clinicopathologic and genetic prognostic factors

Neuroblastoma is the most common extracranial solid tumor in childhood accounting for 8-10% of all childhood malignancies. The tumor is characterized by a spectrum of histopathologic features and a heterogeneous clinical phenotype. Modern multimodality therapy results in variable clinical response ranging from cure in localized tumors to limited response in aggressive metastatic disease. Accurate clinical staging and risk assessment based on clinical, surgical, biologic and pathologic criteria are of pivotal importance in assigning prognosis and planning effective treatment approaches. Numerous studies have analyzed the presence of several clinicopathologic and biologic factors in association with the patient's prognosis and outcome. Although patient's age, tumor stage, histopathologic classification, and MYCN amplification are the most commonly validated prognostic markers, several new gene mutations have been identified in sporadic and familial neuroblastoma cases that show association with an adverse outcome. Novel molecular studies have also added data on chromosomal segmental aberrations in MYCN nonamplified tumors. In this review, we provide an updated summary of the clinical, serologic and genetic prognostic indicators in neuroblastoma including classic factors that have consistently played a role in risk stratification of patients as well as newly discovered biomarkers that may show a potential significance in patients' management.

Heart regeneration, stem cells, and cytokines

The human heart has limited regenerative capacity, which makes the reparative response after the cardiac infarction quite challenging. During the last decade, stem cells have become promising candidates for heart repair, owing to their potent differentiation capacity and paracrine cytokine secretion. Among the different types of stem cells, mesenchymal stem cells have high proliferative potential and secrete numerous cytokines, growth factors, and microRNAs. The paracrine cytokines play important roles in cardiac regeneration, neovascularization, anti-apoptosis, and anti-remodeling mechanisms, among others. This review summarizes the cytokines secreted by stem cells and their relative signaling pathways, which represent key mechanisms for heart regeneration and may serve as a promising future therapeutic strategy for myocardial infarction patients.