Biology subjects

Simons, B.

Publications and source records attributed to Simons, B..

3 recordsLinked to original sources

bioRxiv2025

Xeno-free human iPSC-derived prostate organoid platform for multilineage differentiation and genetic manipulation

Current prostate organoid models rely on tissue-derived material or animal components and lack epithelial and stromal complexity. We defined a xeno-free system to generate human prostate organoids from induced pluripotent stem cells with consistent multilineage differentiation. Floating organoids self-organize into epithelial and stromal domains with basal, luminal, neuroendocrine, fibroblast, and smooth muscle markers. In an alternative modular co-culture system, engineered epithelial progenitors are aggregated with wild-type mesenchymal progenitors, enabling compartment-specific manipulation. Androgen receptor-overexpressing organoids showed increased epithelial AR and PSA expression and proliferation. Single-cell transcriptomics, together with qPCR and immunostaining, confirmed prostate lineage specification and tissue organization. This new xeno-free platform provides a reproducible, scalable, and genetically tractable model to study in-vitro prostate lineage programs, epithelial-stromal interactions, and disease biology. Graphic AbstractThis study describes the generation of prostate organoids from human iPSCs. iPSCs, including those reprogrammed from patients carrying germline mutations, can be differentiated into prostate organoids either through monoculture or by co-culturing endodermal cells with mesenchymal progenitors. Genetic manipulation can be introduced before endoderm specification to model cancer drivers. The resulting multi-lineage organoids exhibit distinct epithelial (AR, NKX3.1, PSA, CK8/18) and stromal (VIM, -SMA) compartments, providing a versatile platform for developmental studies, disease modelling, drug screening, and biomarker discovery. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=120 SRC="FIGDIR/small/683654v1_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@1cc13eborg.highwire.dtl.DTLVardef@12fe2a4org.highwire.dtl.DTLVardef@c89d64org.highwire.dtl.DTLVardef@d541e0_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2025

Cell Type-Specific Effects of miR-21 Loss Attenuate Tumor Progression in MYC-Driven Prostate Cancer

Aberrant microRNA expression is common in cancer, yet cell-type-specific microRNA activity in the tumor microenvironment (TME) remains poorly understood. Here, we show that germline deletion of miR-21 significantly attenuated the progression of MYC-driven prostate cancer (PCa), reducing prostate weight, tumor burden, and proliferation index in Hi-Myc mice. In situ hybridization revealed elevated miR-21 expression in multiple cell types during disease progression. Inflammatory and premalignant lesions in mouse and human prostate showed increased miR-21 in both stroma and epithelium, with further enrichment in the stroma of invasive adenocarcinoma. In Hi-Myc mice, single cell RNA-sequencing revealed miR-21 gene regulation in neoplastic, stromal, and immune cells in a cell-type-specific manner, impacting both direct and indirect targets. Notably, miR-21 deletion reduced immune infiltration into the prostate TME, particularly Trem2-expressing macrophages and regulatory T cells. The Timp1-fibroblast gene signature in MYC-driven PCa was suppressed in miR-21 knockout prostates. Cell-cell communication analysis showed that miR-21 suppressed TGF-beta signaling in the TME, partially through Ski and Smad7 suppression in cancer-associated fibroblasts. These findings underscore the crucial role of miR-21 in PCa and provide some of the first in situ insights into cell-type-specific miRNA activity in solid tumors.

cancer biology↗

bioRxiv2023

Convergent alterations in the tumor microenvironment of MYC-driven human and murine prostate cancer

The tissue microenvironment in prostate cancer is profoundly altered. While such alterations have been implicated in driving prostate cancer initiation and progression to aggressive disease, how prostate cancer cells and their precursors mediate those changes is unclear, in part due to the inability to longitudinally study the disease evolution in human tissues. To overcome this limitation, we performed extensive single-cell RNA-sequencing (scRNA-seq) and rigorous molecular pathology of the comparative biology between human prostate cancer and key time points in the disease evolution of a genetically engineered mouse model (GEMM) of prostate cancer. Our studies of human tissues, with validation in a large external data set, revealed that cancer cell-intrinsic activation of MYC signaling was the top up-regulated pathway in human cancers, representing a common denominator across the well-known molecular and pathological heterogeneity of human prostate cancer. Likewise, numerous non-malignant cell states in the tumor microenvironment (TME), including non-cancerous epithelial, immune, and fibroblast cell compartments, were conserved across individuals, raising the possibility that these cell types may be a sequelae of the convergent MYC activation in the cancer cells. To test this hypothesis, we employed a GEMM of prostate epithelial cell-specific MYC activation in two mouse strains. Cell communication network and pathway analyses suggested that MYC oncogene-expressing neoplastic cells, directly and indirectly, reprogrammed the TME during carcinogenesis, leading to the emergence of cascading cell state alterations in neighboring epithelial, immune, and fibroblast cell types that paralleled key findings in human prostate cancer. Importantly, among these changes, the progression from a precursor-enriched to invasive-cancer-enriched state was accompanied by a cell-intrinsic switch from pro-immunogenic to immunosuppressive transcriptional programs with coinciding enrichment of immunosuppressive myeloid and Treg cells in the immune microenvironment. These findings implicate activation of MYC signaling in reshaping convergent aspects of the TME of prostate cancer as a common denominator across the otherwise well-documented molecular heterogeneity of human prostate cancer.

cancer biology↗