Biology subjects

Isolan, G. R.

Publications and source records attributed to Isolan, G. R..

3 recordsLinked to original sources

bioRxiv2026

A Subset of G Protein-Coupled Serotonin Receptor Genes is Linked to a Neuronal Gene Expression Signature and Clinically Favorable Biology in IDH-Mutant Gliomas

Increasing evidence indicates that neurotransmitter signaling and neuronal interactions are important determinants of glioma biology. However, the clinical and biological significance of serotonin (5-hydroxytryptamine; 5-HT) receptor expression in lower-grade glioma (LGG) remains poorly understood. Here, we investigated G protein-coupled 5-HT receptor genes in LGG using transcriptomic and clinical data from The Cancer Genome Atlas (TCGA-LGG) and Chinese Glioma Genome Atlas (CGGA) cohorts. Initial survival screening identified HTR1A, HTR2A, HTR2C, and HTR6 as the genes most consistently associated with longer overall survival (OS). Multivariable Cox regression further identified HTR2A and HTR6 as independently associated with longer OS after adjustment for age, sex, tumor grade, and IDH/1p19q molecular subtype. Expression of the four genes was preferentially associated with molecular features of less aggressive gliomas, particularly IDH-mutant tumors. Single-cell RNA-sequencing (scRNA-seq) data supported malignant glioma cells as a major source of their expression, while cell-type deconvolution revealed strong positive associations with neuronal enrichment and inverse associations with stromal and immune signatures. Transcriptome-wide co-expression and Gene Ontology analyses showed that all four receptor genes were associated with neuronal and synaptic programs involving neurotransmitter release, synaptic vesicle function, ion channels, and synaptic signaling. These transcriptional programs were particularly coherent in IDH-mutant gliomas and more heterogeneous in IDH-wildtype tumors. Together, these findings identify a subset of 5-HT receptor genes associated with favorable clinical and molecular features in LGG and suggest that their expression may mark a neuronal/synaptic differentiation state, particularly within IDH-mutant gliomas.

cancer biology↗

bioRxiv2026

DLG2-DLG4 expression in lower-grade glioma is associated with improved survival and an excitatory synaptic transmission and plasticity gene signature

Background/ObjectivesIncreasing evidence indicates that gliomas co-opt mechanisms of excitatory synaptic transmission and plasticity to support tumor progression, yet these processes remain poorly characterized in lower-grade gliomas (LGGs). Here, we investigated whether genes associated with excitatory synaptic function are linked to patient prognosis in LGG. MethodsA curated panel of 36 synaptic genes was analyzed in LGG using RNA-sequencing and clinical data from The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) datasets. ResultsAmong the genes investigated, DLG2, DLG3, and DLG4, which encode the postsynaptic scaffolding proteins PSD-93, SAP-102, and PSD-95, respectively, showed strong associations with patient overall survival (OS). Higher expression of each gene was consistently associated with longer OS across both datasets. Expression of DLG2-DLG4 was higher in oligodendroglioma and IDH-mutant, 1p/19q co-deleted tumors, and lower in astrocytoma and IDH-wild-type tumors. Furthermore, expression of all three genes positively correlated with a broad gene signature associated with a synaptic gene program, including multiple components of glutamatergic signaling and postsynaptic organization. ConclusionsThese findings suggest that elevated expression of DLG2-DLG4 is associated with a transcriptional program resembling differentiated neuron-like features and favorable clinical outcome in LGG. Simple SummaryLower-grade gliomas are brain tumors with highly variable outcomes, and better markers are needed to predict how patients will fare. Recent research suggests that these tumors may use mechanisms normally involved in communication between brain cells, but this is not well understood in these cancer types. In this study, we analyzed large patient datasets to examine genes related to synaptic function. We found that higher expression of three genes involved in synaptic membrane organization, DLG2, DLG3, and DLG4 was consistently associated with longer patient survival. These genes were also linked to a broader pattern of gene expression suggestive of neural transmission and plasticity. Our findings suggest that some lower-grade gliomas may adopt characteristics of normal brain cells that are associated with less aggressive behavior. This work may help guide future research on prognostic markers and improve understanding of brain tumor biology.

cancer biology↗

bioRxiv2026

Subgroup-Specific Associations of GRIA Genes Encoding AMPA Glutamate Receptor Subunits with Patient Survival in Medulloblastoma

Brain cancers hijack biological systems involved in neural development and synaptic plasticity. Medulloblastoma (MB), the most common malignant brain tumor in children, is thought to arise from disruptions in neurodevelopmental programs. Glutamatergic transmission mediated by -amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors (AMPARs) has been implicated in synaptic communication between adult brain tumors and surrounding neurons; however, the possible role of AMPARs in MB remains largely unexplored. Here, we analyzed the expression of genes encoding AMPAR subunits, GRIA1-4, in datasets of MB tumor and cell lines, revealing distinct expression patterns and associations with overall survival (OS) across molecular subgroups and histological variants. Expression levels differed among MB molecular subgroups. Analysis using single-cell RNA sequencing (scRNA-seq) was consistent with enrichment of GRIA1 in Group 3 and GRIA4 in SHH MB. Higher GRIA1, GRIA2, and GRIA4 transcription was associated with more favorable patient outcomes in specific MB subgroups. In contrast, high expression of GRIA3 in SHH, or of either GRIA3 or GRIA4 in Group 3 MB, was associated with worse prognosis. Particularly robust but opposing associations with patient survival were found for GRIA3 and GRIA4 in SHH MB. Analysis of GRIA mRNA levels in MB cell lines using both quantitative reverse transcription polymerase chain reaction (qRT-PCR) and data from The Human Protein Atlas, supported some of the gene expression patterns observed in tumors. Together, these findings suggest that GRIA genes and their corresponding AMPAR subunits may have subgroup-specific prognostic relevance in MB.

cancer biology↗