Biology subjects

Shim, J. S.

Publications and source records attributed to Shim, J. S..

5 recordsLinked to original sources

bioRxiv2026

Tumor-infiltrating natural killer cell profiling for therapeutic stratification in patients with resectable non-small cell lung cancer

ObjectiveNeoadjuvant chemoimmunotherapy has improved outcomes in resectable non-small cell lung cancer (NSCLC), yet its real-world implementation is often challenged by surgical delays, immune-mediated fibrosis, and postoperative complications. Smokers with NSCLC, despite a high risk for surgical morbidity, show enhanced responses to neoadjuvant chemoimmunotherapy. This study aimed to identify smoking-associated immune cell determinants that could guide treatment strategies. MethodsSingle-cell RNA sequencing (scRNAseq) was performed on 61 lung tissues from non-smokers and smokers to identify smoking-related immune compositions. The scRNAseq data from 19 invasive lung adenocarcinomas were used to validate their presence in the tumor-immune microenvironment. Bulk RNA sequencing data from 102 resected NSCLC and 24 NSCLC patients treated with neoadjuvant chemoimmunotherapy followed by surgery were used for in silico cellular deconvolution and outcome analyses. ResultsAmong 135 lung cellular phenotypes, two natural killer (NK) cell subsets were strongly associated with smoking and chronic obstructive pulmonary disease (COPD) severity. "Stress-responsive" NK (NKSR) cells exhibited immature features and cytokine-responsive features, and "Adaptive and immunoregulatory NK" (NKAIR) cells showed mature features and elevated multiple immune checkpoint expression. High intratumoral NKSR cells correlated with improved survival after surgery, particularly in current smokers. Conversely, tumors with low NKSR and high NKAIR cells responded more favorably to neoadjuvant chemoimmunotherapy. ConclusionsIntratumoral NK cell phenotyping may aid in therapeutic stratification in patients with NSCLC. NKSR cell preservation predicts benefit from upfront surgery, while NKAIR cell enrichment indicates improved response to neoadjuvant chemoimmunotherapy. These NK cell profiles may help optimize treatment by balancing therapeutic benefit and risk. Graphic Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=112 SRC="FIGDIR/small/696292v1_ufig1.gif" ALT="Figure 1"> View larger version (50K): org.highwire.dtl.DTLVardef@168bc03org.highwire.dtl.DTLVardef@10fa947org.highwire.dtl.DTLVardef@132a92dorg.highwire.dtl.DTLVardef@100e4a4_HPS_FORMAT_FIGEXP M_FIG C_FIG Central Picture O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=81 SRC="FIGDIR/small/696292v1_ufig2.gif" ALT="Figure 2"> View larger version (21K): org.highwire.dtl.DTLVardef@1a2d3b4org.highwire.dtl.DTLVardef@f8f84borg.highwire.dtl.DTLVardef@17510bcorg.highwire.dtl.DTLVardef@9da763_HPS_FORMAT_FIGEXP M_FIG C_FIG NK cell profiling for treatment stratification in resectable NSCLC Central MessageTumor-infiltrating NK cell profiling identifies distinct immune phenotypes that can inform personalized treatment strategies in resectable NSCLC. Perspective statementAbundance of intratumoral stress-responsive NK cells predicts favorable outcomes after upfront surgery, whereas enrichment of adaptive and immunoregulatory NK cells suggests greater benefit from neoadjuvant chemoimmunotherapy. These findings support incorporating NK-cell profiling into preoperative decision-making to optimize therapy selection and balance risks in the high-risk surgical population.

immunology↗

bioRxiv2025

Decrypting cellular engagement and recruitment from spatially resolved transcriptomics

The recruitment of the various types of cells into the tissue microenvironment and how these cells engage with other cells in the tissue sites play critical biological roles. However, it is difficult to study these processes on a genome-wide scale using traditional low-throughput experiments. To address this gap, we developed a fully interpretable multi-instance deep learner, coined "spacer". Spacer digests the transcriptomics and spatial modalities of spatially resolved transcriptomics (SRT) data in alignment with the biological principles of the tissue spatial architecture. We deployed spacer to a panel of 17 high definition and 20 low definition SRT datasets, for studying how stromal and immune cells were recruited into tumors and heart during myocarditis. Spacer discovered novel biological insights not affordable by prior spatial data analysis tools, which were validated by orthogonal immuno-peptidomics, spatial T cell receptor (TCR) sequencing, and single cell sequencing experiments. We discovered genes that encode more immunogenic peptides and that are involved in developmental pathways are more potent in recruiting T cells to local tumor sites, while the recruitment of B cells and macrophages is stipulated by a different molecular program. On the other hand, expression of mucins in the tumor cells was found to repel T cell localization. For the engaging cell side, we also uncovered T cell-intrinsic features that determine their localization, validated by spatial-TCR-seq data. Spacer also unexpectedly revealed that CD4+ T cells, though fewer in numbers, are more responsive than CD8+ T cells in the heart during myocarditis. Collectively, this study establishes a new spatially resolved paradigm for studying cellular localization mechanisms in situ and shifts the paradigm from descriptive mapping to mechanistic discovery.

bioinformatics↗

bioRxiv2024

A florigen-expressing subpopulation of companion cells expresses other small proteins and reveals a nitrogen-sensitive FT repressor

The precise onset of flowering is crucial to ensure successful plant reproduction. The gene FLOWERING LOCUS T (FT) encodes florigen, a mobile signal produced in leaves that initiates flowering at the shoot apical meristem. In response to seasonal changes, FT is induced in phloem companion cells located in distal leaf regions. Thus far, a detailed molecular characterization of the FT-expressing cells has been lacking. Here, we used bulk nuclei RNA-seq and single nuclei RNA (snRNA)-seq to investigate gene expression in FT-expressing cells and other phloem companion cells. Our bulk nuclei RNA-seq demonstrated that FT-expressing cells in cotyledons and true leaves showed differences especially in FT repressor genes. Within the true leaves, our snRNA-seq analysis revealed that companion cells with high FT expression form a unique cluster in which many genes involved in ATP biosynthesis are highly upregulated. The cluster also expresses other genes encoding small proteins, including the flowering and stem growth inducer FPF1-LIKE PROTEIN 1 (FLP1) and the anti-florigen BROTHER OF FT AND TFL1 (BFT). In addition, we found that the promoters of FT and the genes co-expressed with FT in the cluster were enriched for the consensus binding motifs of NITRATE-INDUCIBLE GARP-TYPE TRANSCRIPTIONAL REPRESSOR 1 (NIGT1). Overexpression of the paralogous NIGT1.2 and NIGT1.4 repressed FT expression and significantly delayed flowering under nitrogen-rich conditions, consistent with NIGT1s acting as nitrogen-dependent FT repressors. Taken together, our results demonstrate that major FT-expressing cells show a distinct expression profile that suggests that these cells may produce multiple systemic signals to regulate plant growth and development.

plant biology↗

bioRxiv2024

Triptolide sensitizes cancer cells to nucleoside DNA methyltransferase inhibitors through inhibition of DCTPP1-mediated cell-intrinsic resistance

While nucleoside DNA methyltransferase inhibitors (DNMTi) such as decitabine and azacitidine are effective in treating myelodysplatic syndrome (MDS)/leukemia, they have had limited utility for the majority of other cancers. Through a chemical library screen, we identified that triptolide, a diterpenoid epoxide from Tripterygium wilfordii, or analogs significantly augmented the epigenetic and anti-cancer effects of decitabine in vitro and in vivo. These effects were attributable to inhibition of DCTPP1-mediated cleavage of 5-aza-deoxycytidine triphosphate, the convergent activated metabolite of nucleoside DNMTi, leading to enhanced drug incorporation into genomic DNA, increased DNMT degradation, enhanced global DNA demethylation and associated transcriptional reprogramming. We show that high DCTPP1 expression was associated with cell-intrinsic resistance to nucleoside DNMTi, and that triptolide and its analogs could overcome this resistance. SIGNIFICANCEWe screened a library of existing drugs to identify those capable of enhancing the anti-cancer effects of the nucleoside DNMTi decitabine. The combination of triptolide and decitabine synergistically inhibited cancer cell growth and survival in vitro, and was highly effective in inhibiting xenograft growth in vivo. Biochemical, genetic and structural biology studies with triptolide and its analogs revealed that this synergy was due to their inhibition of DCTPP1-mediated pyrophosphate cleavage from 5-aza-deoxycytidine triphosphate, the active metabolite of DNMTi. The genomic incorporation and efficacy of decitabine in cancer cell lines were significantly correlated with DCTPP1 expression more so than those of other nucleoside metabolizing genes. Triptolide and its analogs comprise rational adjuncts to nucleoside DNMTi ripe for further pre-clinical/clinical translation. HIGHLIGHTSO_LITriptolide synergistically sensitizes cancer cells to DNMTi in vitro. C_LIO_LITriptolide and decitabine combination shows favorable efficacy and safety in vivo. C_LIO_LISynergy of triptolide and decitabine is mediated through inhibition of DCTPP1. C_LIO_LIHigh DCTPP1 expression confers cell intrinsic resistance to DNMTi. C_LI

cancer biology↗

bioRxiv2020

Large-scale Phenotypic Drug Screen Identifies Neuroprotectants in Zebrafish and Mouse Models of Retinitis Pigmentosa

Retinitis pigmentosa (RP) and associated inherited retinal diseases (IRDs) are caused by rod photoreceptor degeneration, necessitating therapeutics promoting rod photoreceptor survival. To address this, we tested compounds for neuroprotective effects in zebrafish and mouse RP models, reasoning drugs effective across species may translate better clinically. We first performed a large-scale phenotypic drug screen using a larval zebrafish model of inducible RP. 2,934 compounds, mostly human-approved drugs, were tested across six concentrations. Statistically, 113 compounds achieved "hit" status. Secondary tests of 42 high-priority hits confirmed eleven lead compounds. Nine leads were then evaluated in mouse RP models, with six exhibiting neuroprotective effects. An analysis of potential mechanisms of action suggested complementary activities. Paired lead compound assays in zebrafish showed additive neuroprotective effects for the majority. These results highlight the value of cross-species phenotypic drug discovery and suggest combinatorial drug therapies may provide enhanced therapeutic benefits for patients with RP and IRDs.

neuroscience↗