Anti-IL-10R antibody improves the therapeutic efficacy of targeted liposomal oligonucleotides

Biological Insight and Recent Advancement in the Treatment of Neuroblastoma

One of the most frequent solid tumors in children is neuroblastoma, which has a variety of clinical behaviors that are mostly influenced by the biology of the tumor. Unique characteristics of neuroblastoma includes its early age of onset, its propensity for spontaneous tumor regression in newborns, and its high prevalence of metastatic disease at diagnosis in individuals older than 1 year of age. Immunotherapeutic techniques have been added to the previously enlisted chemotherapeutic treatments as therapeutic choices. A groundbreaking new treatment for hematological malignancies is adoptive cell therapy, specifically chimeric antigen receptor (CAR) T cell therapy. However, due to the immunosuppressive nature of the tumor microenvironment (TME) of neuroblastoma tumor, this treatment approach faces difficulties. Numerous tumor-associated genes and antigens, including the MYCN proto-oncogene (MYCN) and disialoganglioside (GD2) surface antigen, have been found by the molecular analysis of neuroblastoma cells. The MYCN gene and GD2 are two of the most useful immunotherapy findings for neuroblastoma. The tumor cells devise numerous methods to evade immune identification or modify the activity of immune cells. In addition to addressing the difficulties and potential advancements of immunotherapies for neuroblastoma, this review attempts to identify important immunological actors and biological pathways involved in the dynamic interaction between the TME and immune system.

Novel Treatments and Technologies Applied to the Cure of Neuroblastoma

Neuroblastoma (NB) is the most common extracranial solid tumour in childhood, accounting for approximately 15% of all cancer-related deaths in the paediatric population1. It is characterised by heterogeneous clinical behaviour in neonates and often adverse outcomes in toddlers. The overall survival of children with high-risk disease is around 40-50% despite the aggressive treatment protocols consisting of intensive chemotherapy, surgery, radiation therapy and hematopoietic stem cell transplantation2,3. There is an ongoing research effort to increase NB's cellular and molecular biology knowledge to translate essential findings into novel treatment strategies. This review aims to address new therapeutic modalities emerging from preclinical studies offering a unique translational opportunity for NB treatment.

Strategies to Improve Chimeric Antigen Receptor Therapies for Neuroblastoma

Chimeric antigen receptors (CARs) are among the curative immunotherapeutic approaches that exploit the antigen specificity and cytotoxicity function of potent immune cells against cancers. Neuroblastomas, the most common extracranial pediatric solid tumors with diverse characteristics, could be a promising candidate for using CAR therapies. Several methods harness CAR-modified cells in neuroblastoma to increase therapeutic efficiency, although the assessment has been less successful. Regarding the improvement of CARs, various trials have been launched to overcome insufficient capacity. However, the reasons behind the inadequate response against neuroblastoma of CAR-modified cells are still not well understood. It is essential to update the present state of comprehension of CARs to improve the efficiency of CAR therapies. This review summarizes the crucial features of CARs and their design for neuroblastoma, discusses challenges that impact the outcomes of the immunotherapeutic competence, and focuses on devising strategies currently being investigated to improve the efficacy of CARs for neuroblastoma immunotherapy.

State of the art in immunotherapy of neuroblastoma

Neuroblastoma (NB) is a common and deadly malignancy mostly observed in children. Evolution of therapeutic options for NB led to the addition of immunotherapeutic modalities to the previously recruited chemotherapeutic options. Molecular studies of the NB cells resulted in the discovery of many tumor-associated genes and antigens such as MYCN gene and GD2. MYCN gene and GD2 surface antigen are two of the most practical discoveries regarding immunotherapy of neuroblastoma. The GD2 antigen has been targeted in many animal and human studies including Phase III clinical trials. Even though these antigens have changed the face of pediatric neuroblastoma, they do not take as much credit in immunotherapy of adult-onset neuroblastoma. Monoclonal antibodies have been designed to detect this antigen on the surface of NB tumor cells. Despite bettering the outcomes for NB patients, current therapies still fail in many cases. Studies are underway to discover more specific tumor-associated antigens and more effective treatment options. In the current narrative, immunotherapy of NB - from emerging of this therapeutic backbone in NB to the latest discoveries regarding this malignancy - has been reviewed.

Novel Immunotherapeutic Approaches for Neuroblastoma and Malignant Melanoma

Neuroblastoma (NB) and malignant melanoma (MM), tumors of pediatric age and adulthood, respectively, share a common origin, both of them deriving from the neural crest cells. Although NB and MM have a different behavior, in respect to age of onset, primary tissue involvement and metastatic spread, the prognosis for high stage-affected patients is still poor, in spite of aggressive treatment strategies and the huge amount of new discovered biological knowledge. For these reasons researchers are continuously attempting to find out new treatment options, which in a near future could be translated to the clinical practice. In the last two decades, a strong effort has been spent in the field of translational research of immunotherapy which led to satisfactory results. Indeed, several immunotherapeutic clinical trials have been performed and some of them also resulted beneficial. Here, we summarize preclinical studies based on immunotherapeutic approaches applied in models of both NB and MM.

IL-10 and ARG-1 concentrations in bone marrow and peripheral blood of metastatic neuroblastoma patients do not associate with clinical outcome

The expression of the immunosuppressive molecules IL-10 and arginase 1 (ARG-1), and of FOXP3 and CD163, as markers of regulatory T cells (Treg) and macrophages, respectively, was evaluated in bone marrow (BM) and peripheral blood (PB) samples collected at diagnosis from patients with metastatic neuroblastoma (NB). IL-10 and ARG-1 plasma concentrations were measured and the association of each parameter with patients' outcome was tested. The percentages of immunosuppressive Treg and type-1 regulatory (Tr1) cells were also determined. In both BM and PB samples, IL-10 mRNA expression was higher in metastatic NB patients than in controls. IL-10 plasma concentration was higher in patients with NB regardless of stage. Neither IL-10 expression nor IL-10 plasma concentration significantly associated with patient survival. In PB samples from metastatic NB patients, ARG-1 and CD163 expression was higher than in controls but their expression did not associate with survival. Moreover, ARG-1 plasma concentration was lower than in controls, and no association with patient outcome was found. Finally, in metastatic NB patients, the percentage of circulating Treg was higher than in controls, whereas that of Tr1 cells was lower. In conclusion, although IL-10 concentration and Treg percentage were increased, their contribution to the natural history of metastatic NB appears uncertain.

Effects of Gekko sulfated polysaccharide-protein complex on the defective biorheological characters of dendritic cells under tumor microenvironment

We previously isolated a sulfated polysaccharide-protein complex from Gekko swinhonis Guenther, a traditional Chinese medicine, and have demonstrated its direct anti-cancer effect on human hepatocellular carcinoma cell line SMMC-7721. Here we investigated the effects of Gekko sulfated polysaccharide-protein complex (GSPP) on the defective biorheological characters of dendritic cells (DCs) under SMMC-7721 microenvironment. Our findings have shown that the biorheological properties of DCs were severely impaired by SMMC-7721 microenvironment, including decreased cell deformability, migration, and electrophoresis mobility, increased osmotic fragilities, and changed organizations of cytoskeletal proteins. We also found decreased secretion of interleukin (IL)-12 and increased secretion of IL-10 in DCs. However, supernatant collected from nonmalignant liver cells had no effect on these parameters. SMMC-7721 cells were treated with GSPP and the supernatant was used to culture DCs. We found that the defective biorheological parameters of DCs, except for osmotic fragility, were partially or completely improved. The secretion of IL-12 did not change as compared with that of DCs in SMMC-7721 microenvironment, but the secretion of IL-10 was resumed to the control level. Our results indicate that GSPP could partially restore the defective biorheological characteristics of DCs via modifying the tumor microenvironment and decreasing the secretion of IL-10 of DCs.

Cytokines in neuroblastoma: from pathogenesis to treatment

Cytokines released by cancer cells or by cells of the tumor microenvironment stimulate angiogenesis, act as autocrine or paracrine growth factors for malignant cells, promote tumor cell migration and metastasis or create an immunosuppressive microenvironment. These tumor-promoting effects of cytokines also apply to neuroblastoma (NB), a pediatric neuroectodermal malignancy with frequent metastatic presentation at diagnosis and poor prognosis. IL-6 and VEGF are the best characterized cytokines that stimulated tumor growth and metastasis, while others such as IFN-γ can exert anti-NB activity by inducing tumor cell apoptosis and inhibiting angiogenesis. On the other hand, cytokines are part of the anti-NB therapeutic armamentarium, as exemplified by IL-2 and granulocyte-macrophage colony stimulating factor that potentiate the activity of anti-NB antibodies. These recent results raise hope for more efficacious treatment of this ominous pediatric malignancy.

Neuroblastoma-targeted nanoparticles entrapping siRNA specifically knockdown ALK

RNA interference molecules have some advantages as cancer therapeutics, including a proved efficacy on both wild-type (WT) and mutated transcripts and an extremely high sequence-specificity. The most significant hurdle to be overcome if exogenous small interfering RNAs (siRNA) is to be used therapeutically is the specific, effective, nontoxic delivery of siRNA to its intracellular site of action. At present, human applications are confined almost exclusively to targets within the liver, where the delivery systems naturally accumulate, and extra-hepatic targets remain a challenge. Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase that has recently been shown to contribute to the cell growth and progression of human neuroblastoma (NB). We investigated its potential as a therapeutic target in NB by generating anti-GD₂-targeted nanoparticles that carry ALK-directed siRNA, which are specifically and efficiently delivered to GD₂-expressing NB cells. Relative to free ALK-siRNA, anti-GD₂-targeted liposomal formulations of ALK-siRNA had low plasma clearance, increased siRNA stability, and improved binding, uptake, silencing and induction of cell death, and specificity for NB cells. In NB xenografts, intravenous (i.v.) injection of the targeted ALK-siRNA liposomes showed gene-specific antitumor activity with no side effects. ALK-selective siRNA entrapped in anti-GD₂-targeted nanoparticles is a promising new modality for NB treatment.

Therapeutic targeting of TLR9 inhibits cell growth and induces apoptosis in neuroblastoma

The Toll-like receptor 9 (TLR9) evolved to cope with pathogens, but it is expressed in a variety of tumors for reasons that are unclear. In this study, we report that neuroblastoma (NB) cells express functional TLR9. Liposome-complexed CpG oligonucleotides inhibited the proliferation of TLR9-expressing NB cells and induced caspase-dependent apoptotic cell death. Inhibitory oligonucleotides (iODNs) abrogated these effects. RNA interference reduced TLR9 expression but not to the level where functional responses to CpG were abolished. Compared with free CpG, liposomal formulations of NB-targeted CpG (TL-CpG) significantly prolonged the survival of mice bearing NB tumor xenografts. While CpG alone lacked antitumor efficacy in NOD/SCID/IL2rg(-/-) mice, TL-CpG retained significant efficacy related to direct effects on tumor cells. TLR9 expression in primary human NB specimens was found to correlate inversely with disease stage. Our findings establish functional expression of TLR9 in NB and suggest that TLR9 may represent a novel theranostic target in this disease.