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Biomedical subjects

Se-Young Jo

Publications and source records attributed to Se-Young Jo.

2 recordsLinked to original sources

Putative glioblastoma origin-like cells in the subventricular zone: isolation and characterization.

Glioblastoma (GBM) remains lethal despite maximal therapy. The adult subventricular zone (SVZ), a neural stem-cell niche, has been implicated as a potential site of origin, yet the identity and functional properties of putative GBM origin-like cells (GBM-OCs) within the SVZ remain unclear. An SVZ-restricted somatic mutation mouse model (Cre-induced EGFRvIII expression with Trp53 and Pten disruption) was established and mouse SVZ-derived cells were prospectively isolated for functional and molecular profiling. Self-renewal, multipotency, invasive potential and tumour-initiating capacity were assessed relative to control SVZ cells and matched tumour-derived tumourspheres. Whole-genome and RNA sequencing defined genomic and transcriptional alterations during early progression. Mouse GBM-OCs exhibited self-renewal and multilineage differentiation and initiated tumours only after re-implantation into the SVZ (11/29, 38%), whereas direct striatal implantation failed (0/25, 0%), indicating context-dependent tumorigenic potential associated with the SVZ microenvironment. In contrast, tumour-derived tumourspheres retained tumorigenic capacity upon implantation into both the SVZ and the striatum. During progression from mouse GBM-OCs to tumours, whole-chromosome and arm-level aneuploidies accumulated. In patients with GBM, multi-region single-nucleus RNA sequencing of tumour-free SVZ, matched tumours and tumour-free cortex identified rare neural stem cell-like, astrocyte-like and oligodendrocyte precursor-like SVZ populations transcriptionally aligned with GBM programmes. These cells showed single-nucleus RNA-inferred chromosome 7 gain and/or chromosome 10 loss signals, with concordant low-frequency copy-number alterations in the SVZ detected by exome sequencing and enriched in matched tumours. Together, these findings support the presence of SVZ-resident stem or progenitor-like populations with early GBM-associated features, consistent with putative GBM-OCs, and highlight the SVZ niche as a potential target for early detection and niche-informed therapeutic strategies.

Animals

Analysis of targeted and whole genome sequencing of PacBio HiFi reads for a comprehensive genotyping of gene-proximal and phenotype-associated Variable Number Tandem Repeats.

Variable Number Tandem repeats (VNTRs) refer to repeating motifs of size greater than five bp. VNTRs are an important source of genetic variation, and have been associated with multiple Mendelian and complex phenotypes. However, the highly repetitive structures require reads to span the region for accurate genotyping. Pacific Biosciences HiFi sequencing spans large regions and is highly accurate but relatively expensive. Therefore, targeted sequencing approaches coupled with long-read sequencing have been proposed to improve efficiency and throughput. In this paper, we systematically explored the trade-off between targeted and whole genome HiFi sequencing for genotyping VNTRs. We curated a set of 10&#xa0;,&#xa0;787 gene-proximal (G-)VNTRs, and 48 phenotype-associated (P-)VNTRs of interest. Illumina reads only spanned 46% of the G-VNTRs and 71% of P-VNTRs, motivating the use of HiFi sequencing. We performed targeted sequencing with hybridization by designing custom probes for 9,999 VNTRs and sequenced 8 samples using HiFi and Illumina sequencing, followed by adVNTR genotyping. We compared these results against HiFi whole genome sequencing (WGS) data from 28 samples in the Human Pangenome Reference Consortium (HPRC). With the targeted approach only 4,091 (41%) G-VNTRs and only 4 (8%) of P-VNTRs were spanned with at least 15 reads. A smaller subset of 3,579 (36%) G-VNTRs had higher median coverage of at least 63 spanning reads. The spanning behavior was consistent across all 8 samples. Among 5,638 VNTRs with low-coverage (&#xa0;<&#xa0;15), 67% were located within GC-rich regions (&#xa0;>&#xa0;60%). In contrast, the 40X WGS HiFi dataset spanned 98% of all VNTRs and 49 (98%) of P-VNTRs with at least 15 spanning reads, albeit with lower coverage. Spanning reads were sufficient for accurate genotyping in both cases. Our findings demonstrate that targeted sequencing provides consistently high coverage for a small subset of low-GC VNTRs, but WGS is more effective for broad and sufficient sampling of a large number of VNTRs.

Minisatellite Repeats