Biology subjects

Xuan, S.

Publications and source records attributed to Xuan, S..

6 recordsLinked to original sources

bioRxiv2025

Dual pathway regulation of castration response and ferroptosis in the prostate epithelium

Understanding how sex hormones maintain tissue integrity--and how their disruption can promote cancer--is a central question in biology. In the prostate, androgen signaling is crucial for development, homeostasis, and cancer, yet the molecular mechanisms underlying tissue regression after androgen-deprivation have remained unknown. Here we show that castration induces epithelial regression via ferroptosis in the normal mouse and human prostate, as well as in prostate tumors. Using in vivo analyses in genetically-engineered mice, supported by validation in human organotypic cultures, we demonstrate that androgen receptor (AR) signaling controls castration response through two distinct pathways: an intrinsic luminal epithelial pathway regulated by the prostate-specific transcription factor NKX3.1, and an extrinsic stromal signal mediated by the secreted factor pleiotrophin (PTN). Together, these AR signaling pathways coordinately regulate biosynthesis of monounsaturated fatty acid (MUFA) phospholipids and GPX4 expression to suppress prostate epithelial ferroptosis. Our findings reveal a sex hormone-regulated ferroptotic program that governs tissue homeostasis and suggest that ferroptosis induction could represent a new therapeutic strategy for prostate cancer.

developmental biology↗

bioRxiv2025

Sequencing-based Spatial Transcriptomics with scRNA-seq Sensitivity

The advent of spatial transcriptomics has dramatically expanded our ability to study the vast network of cell-cell interactions at the molecular level in tissue. Among current methods, sequencing-based approaches have great potential in discovering because of its unbiased capture. In the last couple of years, the spatial resolution for the capture addresses has been significantly improved from 100 m to <1 m, well below the size of a mammalian cell. However, the capture efficiency has always been a pain point, [~]one order of magnitude lower than that of single cell RNA sequencing (scRNA-seq). The low capture efficiency limits the depth and breadth of its applications in the study of complex biological systems and diseases. Here, we introduce Salus Spatial transcriptomic system (Salus-STS), which provides [~]1 m capture resolution and a capture efficiency [~]1 order of magnitude higher than other current methods. Analysis with sub-cellular resolution becomes practical for sequencing-based spatial transcriptomics.

molecular biology↗

bioRxiv2020

Molecular and clinicopathological characterization of a prognostic immune gene signature associated with MGMT methylation in glioblastoma

BackgroundO6-methylguanine-DNA methyltransferase (MGMT) methylation status affects tumor chemo-resistance and the prognosis of glioblastoma (GBM) patients. We aimed to investigate the role of MGMT methylation in the regulation of GBM immunophenotype and discover an effective biomarker to improve prognosis prediction of GBM patients. MethodsA total of 769 GBM patients with clinical information from five independent cohorts were enrolled in the present study. Samples from the Cancer Genome Atlas (TCGA) dataset were used as the training set, whereas transcriptome data from the Chinese Glioma Genome Atlas (CGGA) RNA-seq, CGGA microarray, GSE16011, and the Repository for Molecular Brain Neoplasia (REMBRANDT) cohort were used for validation. A series of bioinformatics approaches were carried out to construct a prognostic signature based on immune-related genes, which were tightly related with the MGMT methylation status. The influence of the signature on immunosuppression and remodeling of the tumor microenvironment were comprehensively investigated. Then, the utility of this immune gene signature was analyzed by the development and evaluation of a nomogram. ResultsWe found that MGMT unmethylation was closely associated with immune-related biological processes in GBM. Sixty-five immune genes were more highly expressed in the MGMT unmethylated than the MGMT methylated group. An immune gene-based risk model was further established to divide patients into high and low-risk groups, and the prognostic value of this signature was validated in several GBM cohorts. Functional analyses manifested a universal up-regulation of immune-related pathways in the high-risk group as compared to the low-risk group. Furthermore, the risk score was highly correlated to the immune cell infiltration, immunosuppression, inflammatory activities, as well as the expression levels of immune checkpoints. Finally, a nomogram was developed for clinical application. ConclusionsMGMT methylation is strongly related to the immune responses in GBM. The immune gene-based signature we identified may have potential implications in predicting the prognosis of GBM patients and mechanisms underlying the role of MGMT methylation.

cancer biology↗

bioRxiv2020

A single-cell atlas of the mouse and human prostate reveals heterogeneity and conservation of epithelial progenitors

Understanding the cellular constituents of the prostate is essential for identifying the cell of origin for benign prostatic hyperplasia and prostate adenocarcinoma. Here we describe a comprehensive single-cell atlas of the adult mouse prostate epithelium, which demonstrates extensive heterogeneity. We observe distinct lobe-specific luminal epithelial populations (LumA, LumD, LumL, and LumV) in the distal region of the four prostate lobes, a proximally-enriched luminal population (LumP) that is not lobe-specific, as well as a periurethral population (PrU) that shares both basal and luminal features. Functional analyses suggest that LumP and PrU cells have multipotent progenitor activity in organoid formation and tissue reconstitution assays. Furthermore, we show that mouse distal and proximal luminal cells are most similar to human acinar and ductal populations, that a PrU-like population is conserved between species, and that the mouse lateral prostate is most similar to the human peripheral zone. Our findings elucidate new prostate epithelial progenitors, and help resolve long-standing questions about the anatomical relationships between the mouse and human prostate.

developmental biology↗

bioRxiv2020

Molecular and clinical characterization of 5mC regulators in glioma: results of a multicenter study

DNA methylation has been widely reported to associate with the progression of glioma. DNA methylation at the 5 position of cytosine (5-methylcytosine, 5mC), which is regulated by 5mC regulators ("writers", "erasers" and "readers"), is the most critical modification pattern. However, a systematic study on the role of these regulators in glioma is still lacking. In this study, we collected gene expression profiles and corresponding clinical information of gliomas from three independent public datasets. Gene expression of 21 5mC regulators was analyzed and linked to clinicopathological features. A novel molecular classification of glioma was developed using consensus non-negative matrix factorization (CNMF) algorithm, and the tight association with molecular characteristics as well as tumor immune microenvironment was clarified. Sixteen prognostic factors were identified using univariate Cox regression analysis, and a 5mC regulator-based gene signature was further constructed via the least absolute shrinkage and selection operator (LASSO) cox analysis. This risk model was proved as an efficient predictor of overall survival for diffuse glioma, glioblastoma (GBM), and low-grade glioma (LGG) patients in three glioma cohorts. The significant correlation between risk score and intratumoral infiltrated immune cells, as well as immunosuppressive pathways, was found, which explained the difference in clinical outcomes between high and low-risk groups. Finally, a nomogram incorporating the gene signature and other clinicopathological risk factors was established, which might direct clinical decision making. In summary, our work highlights the potential clinical application value of 5mC regulators in prognostic stratification of glioma and their potentialities for developing novel treatment strategies.

cancer biology↗

bioRxiv2019

Ins2 gene bursting activity defines a mature beta-cell state

Transcriptional and functional cellular specialization has been described for insulin-secreting {beta}-cells of the endocrine pancreas. However, it is not clear whether {beta}-cell heterogeneity is stable or reflects dynamic cellular states. We investigated the temporal kinetics of endogenous insulin gene activity using live cell imaging, with complementary experiments employing FACS and single cell RNA sequencing, in {beta}-cells from Ins2GFP knock-in mice. In vivo staining and FACS analysis of islets from Ins2GFP mice confirmed that at a given moment, ~25% of {beta}-cells exhibited significantly higher activity at the conserved insulin gene Ins2. Live cell imaging captured Ins2 gene activity dynamics in single {beta}-cells over days. Autocorrelation analysis revealed a subset of cells with oscillating behavior, with mean oscillation periods of 17 hours. Increased glucose concentrations stimulated more cells to oscillate and resulted in higher average Ins2 gene activity per cell. Single cell RNA sequencing showed that Ins2(GFP)HIGH {beta}-cells were enriched for markers of {beta}-cell maturity. Ins2(GFP)HIGH {beta}-cells were also significantly less viable at all glucose concentrations and in the context of ER stress. Collectively, our results demonstrate that the heterogeneity of insulin production, observed in mouse and human {beta}-cells, can be accounted for by dynamic states of insulin gene activity. BlurbPreviously reported pancreatic {beta}-cell heterogeneity reflects {beta}-cell state transitions.

cell biology↗