Biology subjects

Scheele, C. L.

Publications and source records attributed to Scheele, C. L..

5 recordsLinked to original sources

bioRxiv2024

Chemotherapy-driven de novo Wnt pathway activation dictates a dynamic shift to a drug-tolerant state in breast cancer cells

The efficacy of chemotherapy is often hindered by the enrichment of a population of cancer cells that enter a drug-tolerant persister (DTP) state, mimicking embryonic diapause, yet the underlying mechanisms of this transition remain poorly understood. This study demonstrates that both parental and chemotherapy-induced Wnt-active (WntHigh) cells in Triple-negative breast cancer exhibit transcriptional and functional properties characteristic of DTP cells, including a diapause transcriptional signature, reduced MYC expression, reversible restricted proliferation, and pronounced chemoresistance. Our findings reveal that the de novo activation of the Wnt signaling pathway, triggered by the transcriptional upregulation of components essential for canonical Wnt ligand-secretion and -activation, is critical for enriching the diapause-DTP (DTPDiap) population across various chemotherapy regimens. The diapause-DTP/WntHigh population can be selectively ablated by concomitant, rather than sequential, pharmacological inhibition of Wnt ligand-secretion alongside chemotherapy, highlighting new vulnerabilities in DTPDiap cell-emergence and potentially yielding a therapeutic opportunity against DTPs. This study shows that activation of Wnt signaling pathway is sufficient and necessary for the induction of a DTPDiap state and enhances our understanding of the introductory mechanisms driving DTP cell-enrichment upon chemotherapy.

cancer biology↗

bioRxiv2023

Morphometric analysis of the terminal ductal lobular unit architecture in human breast

AbstractThe major lactiferous ducts of the human breast branch out and ultimately end at terminal ductal lobular units (TDLUs). These glandular structures are the source of milk upon lactation, and also the most common origin of breast cancer. Despite their functional and clinical importance, the three dimensional (3D) architecture of TDLUs has remained undetermined, largely due to their absence in rodent animal models. By utilizing recent technological advances in optical tissue clearing, 3D reconstruction histology and microscopy, we imaged the 3D structure of healthy human breast tissue to determine whether general branching patterns or cell type specific niches exist in the TDLU. Our data demonstrate that highly branched TDLUs, also exhibiting elevated proliferation, are uncommon in the breast tissue regardless of donor age, parity or hormonal contraception. Overall, TDLUs have a consistent shape and their branch parameters are largely comparable between different TDLUs and individuals irrespective of donor age or parity. Simulation of TDLU branching morphogenesis in 3D by mathematical modelling suggests that evolutionarily conserved mechanisms regulate mammary gland branching in humans and mice, despite their anatomical differences. The data also demonstrate a new level of organization within the TDLU structure identifying a main subtree that dominates in bifurcation events and exhibits a more duct-like keratin expression pattern. In all, our data provide the first structural insights into 3D human breast anatomy and branching, and exemplify the power of volumetric imaging in deeper understanding of human breast biology. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=85 SRC="FIGDIR/small/532249v2_ufig1.gif" ALT="Figure 1"> View larger version (28K): org.highwire.dtl.DTLVardef@16caf77org.highwire.dtl.DTLVardef@73d65dorg.highwire.dtl.DTLVardef@fea93eorg.highwire.dtl.DTLVardef@1192c1c_HPS_FORMAT_FIGEXP M_FIG C_FIG

developmental biology↗

bioRxiv2021

Myosin-X-dependent assembly of the extracellular matrix limits breast cancer invasion

Ductal carcinoma in situ (DCIS) is a pre-invasive stage of breast cancer, where the tumor is encapsulated by a basement membrane (BM). At the invasive phase, the BM barrier is compromised enabling tumor cells to escape into the surrounding stroma. The molecular mechanisms that establish and maintain an epithelial BM barrier in vivo are poorly understood. Myosin-X (MYO10) is a filopodia-inducing motor protein implicated in metastasis and poor clinical outcome in patients with invasive breast cancer (IBC). We compared MYO10 expression in patient-matched normal breast tissue and DCIS lesions and found elevated MYO10 expression in DCIS samples, suggesting that MYO10 might facilitate the transition from DCIS to IBC. Indeed, MYO10 promoted the formation of filopodia and cell invasion in vitro and positively regulated the dissemination of individual cancer cells from IBC lesions in vivo. However, MYO10-depleted DCIS xenografts were, unexpectedly, more invasive. In these xenografts, MYO10 depletion compromised BM formation around the lesions resulting in poorly defined tumor borders and increased cancer cell dispersal into the surrounding stroma. Moreover, MYO10-depleted tumors showed increased EMT-marker-positive cells, specifically at the tumor periphery. We also observed cancer spheroids undergoing rotational motion and recruiting BM components in a filopodia-dependent manner to generate a near-continuous extracellular matrix boundary. Taken together, our data identify a protective role for MYO10 in early-stage breast cancer, where MYO10-dependent tumor cell protrusions support BM assembly at the tumor-stroma interface to limit cancer progression, and a pro-invasive role that facilitates cancer cell dissemination at later stages. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=123 SRC="FIGDIR/small/464987v2_ufig1.gif" ALT="Figure 1"> View larger version (28K): org.highwire.dtl.DTLVardef@d90a4eorg.highwire.dtl.DTLVardef@133ba9borg.highwire.dtl.DTLVardef@1204a05org.highwire.dtl.DTLVardef@dba254_HPS_FORMAT_FIGEXP M_FIG C_FIG Highlights- Filopodia sculpt the tumor-proximal stroma in pre-invasive ductal carcinoma in situ (DCIS). - Filopodia-dependent basement membrane (BM) assembly limits invasive transition of DCIS-like tumors in vivo. - Loss of MYO10-dependent filopodia impairs BM assembly and induces an EMT-like phenotype at the tumor-stroma interface in vivo. - MYO10 filopodia are anti-invasive in DCIS but facilitate dissemination in invasive breast cancer.

cell biology↗

bioRxiv2021

Annexin A1 is a polarity cue that directs planar mitotic spindle orientation during mammalian epithelial morphogenesis

Oriented cell divisions are critical for the formation and maintenance of structured epithelia. Proper mitotic spindle orientation relies on polarised anchoring of force generators to the cell cortex by the evolutionarily conserved Gi-LGN-NuMA complex. However, the polarity cues that control cortical patterning of this ternary complex remain largely unknown in mammalian epithelia. Here we identify the membrane-associated protein Annexin A1 (ANXA1) as a novel interactor of LGN in mammary epithelial cells. ANXA1 acts independently of Gi to instruct the accumulation of LGN and NuMA at the lateral cortex to ensure cortical anchoring of Dynein-Dynactin and astral microtubules and thereby planar alignment of the mitotic spindle. Loss of ANXA1 randomises mitotic spindle orientation, which in turn disrupts epithelial architecture and luminogenesis in three-dimensional cultures of primary mammary epithelial cells. Our findings establish ANXA1 as an upstream cortical cue that regulates LGN to direct planar cell divisions during mammalian epithelial morphogenesis.

cell biology↗

bioRxiv2020

Single Cell Analysis of Regions of Interest (SCARI) using a novel photoswitchable tag

The functional activity and differentiation potential of cells is determined by their interaction with surrounding cells. Approaches that allow the unbiased characterization of cell states while at the same time providing spatial information are of major value to assess this environmental influence. However, most current techniques are hampered by a trade-off between spatial resolution and cell profiling depth. Here, we developed a photoswitch-based technology that allows the isolation and in-depth analysis of live cells from regions of interest in complex ex vivo systems, including human tissues. The use of a highly sensitive 4-nitrophenyl(benzofuran)-cage coupled to nanobodies allowed photoswitching of cells in areas of interest with low-intensity violet light and without detectable phototoxicity. Single cell RNA sequencing of spatially defined CD8+ T cells was used to exemplify the feasibility of identifying location-dependent cell states at the single cell level. Finally, we demonstrate the efficient labeling and photoswitching of cells in live primary human tumor tissue. The technology described here provides a valuable tool for the analysis of spatially defined cells in diverse biological systems, including clinical samples.

bioengineering↗