Pediatric Solid Cancers: Dissecting the Tumor Microenvironment to Improve the Results of Clinical Immunotherapy

Pediatric gliomas immunity challenges and immunotherapy advances

Pediatric gliomas, the most frequent brain tumors in children, are characterized by heterogeneity and a unique tumor immune microenvironment. They are categorized into different subtypes, including low-grade gliomas like pilocytic astrocytomas and high-grade gliomas such as diffuse midline gliomas and diffuse intrinsic pontine gliomas, each exhibiting distinct immunological profiles. The tumor immune microenvironment in pediatric gliomas is shaped by cellular and non-cellular components, including immune cells, cytokines, and the extracellular matrix, involved in tumor progression, immune evasion, and response to therapy. While pediatric low-grade gliomas often display an immunosuppressed microenvironment, high-grade gliomas are characterized by complex immune infiltrates and intricate immunosuppressive mechanisms. The blood-brain barrier further obscures immune cell recruitment and therapeutic delivery. Despite advances in understanding adult gliomas, the immunobiology of pediatric tumors is poorly investigated, with limited data on the interactions between glioma cells and immune populations such as T and natural killer cells, as well as tumor-associated macrophages. Herein, we provide an update of the current knowledge on tumor immune microenvironment interactions in pediatric gliomas, highlighting the immunosuppressive mechanisms and emerging immunotherapeutic strategies aiming at overcoming these barriers to improve clinical outcomes for affected children.

Argatroban and Menadione exert protective effects in ultraviolet-irradiated skin inflammation: A transcriptomic analysis based on identification of iron overload related biomarkers

Ultraviolet light (UV) can cause serious damage to human skin. The inflammatory reaction arising from repeated UV exposure leads to severe skin lesions and even promotes photo-carcinogenesis. Iron overload is featured by excessive iron intake and deposition and will promote inflammatory response inside cells. However, the core molecules involved in UV radiation induced iron overload and related anti-inflammatory strategies remain unclear. Signature genes involved in UV-irradiated skin were filtered through integrated datasets from the Gene Expression Omnibus (GEO) database. Subsequently, immune cell infiltration analysis was carried out to examine the relationship between signature gene expression and immune cell abundance. Single cell RNA-seq matrix data implicated in UV-irradiated skin was then applied to assess the expression level of signature genes in different cell clusters and to find out the core cell type and the key signaling pathway involved in UV radiation. Finally, cytological and animal experiments were conducted to investigate the potential of signature genes as therapeutic targets. SAT1 and RBMS1 were screened and validated as signature genes of UV irradiation. Immune cell infiltration analysis demonstrated that SAT1 and RBMS1 expression were associated closely with immune cell abundance, and skin fibroblasts were identified as the central cell type to communicate with other cell clusters in UV-irradiated skin. Disturbance of SAT1 exerted observably more suppressive effects on the release of inflammatory cytokines than overexpression of RBMS1. Two small molecule drugs targeting SAT1, namely Argatroban and Menadione, were predicted. Moreover, their therapeutic potentials in the treatment of UV-irradiated skin injury were confirmed experimentally.

Neuroblastoma-A Review of Combination Immunotherapy

Neuroblastoma is the most common extracranial solid tumor found in childhood and is responsible for 15% of deaths among children with cancer. Although multimodal therapies focused on surgery, chemotherapy, radiotherapy, and stem cell transplants have favorable results in many cases, the use of conventional therapies has probably reached the limit their possibility. Almost half of the patients with neuroblastoma belong to the high-risk group. Patients in this group require a combination of several therapeutic approaches. It has been shown that various immunotherapies combined with conventional methods can work synergistically. Due to the development of such therapeutic methods, we present combinations and forms of combining immunotherapy, focusing on their mechanisms and benefits but also their limitations and potential side effects.