Biology subjects

Cipitria, A.

Publications and source records attributed to Cipitria, A..

16 recordsLinked to original sources

bioRxiv2026

Matrix biophysical cues drive transient or prolonged breast cancer dormancy programmes

Breast cancer metastasis can emerge after disease-free periods through the reawakening of dormant disseminated cancer cells. Despite evidence that the extracellular matrix (ECM) modulates this phenomenon, biophysical cues regulating dormancy fate and therapeutic responses remain poorly understood. Here, we engineered stiffness-matched gelatin methacryloyl (GelMA) and alginate-based 3D matrices to disentangle matrix stiffness from adhesion and degradability and uncover their contributions to dormancy. Deep learning-based 3D segmentation revealed that adhesive and degradable matrices supported rounded and proliferative tumour masses, whereas inert matrices favoured single cell dormancy. Within inert matrices, stiffness further determined dormancy fate, with soft matrices activating SOX9-associated transient stem-like dormancy, while stiff matrices reduced cell volume, increased intracellular macromolecular crowding of proteins and induced NR2F1-associated prolonged dormancy marked by autophagy and cellular stress. Transiently dormant cells retrieved from soft matrices retained dormancy memory and failed to form tumours in chicken chorioallantoic membranes, demonstrating persistence of matrix-induced states after removal of biophysical cues. Moreover, patient-derived cells in soft inert matrices recapitulated transient dormant states and exhibited therapy resistance. We demonstrate that tuneable biophysical cues shape distinct dormancy states, linking matrix mechanics to dormancy regulation and therapeutic response.

bioengineering↗

bioRxiv2026

Patterned alginate hydrogel spatially guides collagen fibrillogenesis, viscoelasticity and endothelial cell invasion

Angiogenesis following injury has been shown to be driven by fibrillar proteins of the extracellular matrix (ECM), such as collagen. However, the use of protein-based biomaterials presents some challenges, such as uncontrolled degradation and limited tuneability. We demonstrate how to create patterned interpenetrating networks (IPNs) based on covalently crosslinked alginate and physically crosslinked collagen that provide suitable mechanical properties to support migration of endothelial cells (ECs) in a spatially controlled manner. Low molecular weight alginate is functionalized with norbornene (N) or tetrazine (T), which enables two independent covalent crosslinking methods: UV-mediated and degradable crosslinks with matrix metalloproteinase (MMP) sensitive peptides (Deg) and slower spontaneous N:T non-degradable crosslinks (noDeg). Using photolithography, patterns in degradation, collagen fibrillogenesis, microarchitecture and matrix viscoelasticity are created. The potential of such 3D patterned alginate-collagen (Alg-Col) IPNs to spatially guide EC invasion and proliferation was tested in a microfluidics platform resembling an early healing setting. Only regions combining collagen fibrillogenesis, alginate degradability and viscoelasticity demonstrated EC cell invasion similar to the ones found in vivo following injury. The 3D patterned Alg-Col IPNs are compatible with microfluidics, offer an strategy to widen the applications of protein-based hydrogels and present a versatile platform for tissue engineering and disease modeling.

bioengineering↗

bioRxiv2026

Extracellular Matrix Mechanobiology in Pancreatic Ductal Adenocarcinoma: Correlating In Vivo Patient Magnetic Resonance Elastography with Ex Vivo Tissue Mechanics and Histopathology

Pancreatic ductal adenocarcinoma (PDAC) is characterized by a dense desmoplastic extracellular matrix (ECM) that contributes to tumor progression, therapeutic resistance, and poor patient survival. However, the relationship between in vivo imaging-derived mechanical properties, ex vivo tissue biomechanics, ECM architecture, and cellularity remains incompletely understood. Here, we combined pre-operative in vivo clinical magnetic resonance elastography (MRE) with ex vivo biomechanical testing of fresh human PDAC tissue and histopathological analyses. Nine patients undergoing pancreatic resection were prospectively enrolled. Quantitative MRE was performed pre-operatively to assess tissue stiffness through shear wave speed (c) and relative viscosity or fluidity through the loss angle ({varphi}). Fresh tumor and adjacent non-malignant tissue biopsies were subsequently analyzed ex vivo by unconfined uniaxial compression testing to determine elastic moduli and stress relaxation halftime. Histological analyses quantified collagen-rich fibrous tissue area, cell nuclei density, and nuclear morphology. Tumor tissue exhibited significantly increased stiffness and collagen fraction compared with adjacent non-malignant tissue, together with reduced cellularity, smaller nuclear area and more elongated nuclei. Ex vivo stiffness positively correlated with collagen content and negatively correlated with patient survival. Reduced stress relaxation halftime, indicative of increased tissue viscosity, was associated with lower cellularity and elongated nuclei. Importantly, pre-operative MRE parameters of the intact surrounding environment correlated significantly with ex vivo tumor mechanics, cellular organization, and survival. Specifically, a softer and less viscous surrounding environment was associated with stiffer and more viscous tumors, with lower cellularity and elongated nuclei, and poorer prognosis. These findings demonstrate that MRE-derived mechanical biomarkers reflect underlying ECM remodeling and tumor mechanobiology in PDAC. Integrating in vivo imaging with ex vivo tissue mechanics and histopathology may improve non-invasive disease characterization and support biomechanically-informed therapeutic strategies.

bioengineering↗

bioRxiv2026

Dynamic cancer dormancy and awakening emerge from tumor microenvironment feedback in a minimal theoretical model

Cancer cell dormancy is characterized by late relapse and therapy resistance, yet the mechanisms that awaken dormant cells remain poorly understood. The tumor microenvironment has emerged as a key driver of these state transitions. Here we present a theoretical framework based on evolutionary game theory in which interactions between cancer and host cells are coupled explicitly to a changing tumor microenvironment. Cancer cells produce a conditioning factor that is cleared by the microenvironment and tolerated only up to a threshold. Through this conditioning factor, the microenvironment feeds back on cancer-host interactions and reshapes their competitive balance. Unlike a model with fixed interactions, this feedback allows dormancy and awakening to emerge as dynamic outcomes of microenvironmental change. We show that this minimal coupling is sufficient to generate distinct long-term regimes. Across these regimes, feedback generates thresholds and history dependence, so that the same cancer population can follow different fates depending on whether the microenvironment is already primed. Our framework reduces these dynamics to experimentally and biologically interpretable parameters linked to conditioning factor production, clearance, tolerance, and microenvironment-dependent changes in cancer-host competition. More broadly, it provides a quantitative basis for testing how collective microenvironmental feedback shapes cancer dormancy and awakening, and for designing experiments to uncover the mechanisms that awaken dormant cancer cells.

systems biology↗

bioRxiv2026

Lung-mimicking click alginate-dECM model of breast cancer lung metastasis reveals the role of ECM mechanics in tumor growth dynamics and genomic instability

Metastatic breast cancer (BC) is the main cause of cancer-related death in women. Accumulating evidence highlights the prominent changes within the lung metastatic niche, resulting in stiffening of the extracellular matrix (ECM). The prevailing concept of cancer evolution encompasses the acquisition of beneficial traits as a consequence of genomic instability, yet it remains elusive to what extend altered lung ECM mechanics feed into this. To investigate this, a tunable 3D bioengineered model, capturing the biophysical and biochemical characteristics of the BC metastatic lung niche is developed. Porcine derived lung decellularized ECM (dECM), combined with norbornene and tetrazine modified click-crosslinkable alginate, recapitulates composition and mechanics of healthy soft (3 kPa) and metastatic stiff (13 kPa) lung niches. Label-free optical microscopy further validates the microarchitectural resemblance between resulting matrices and human lung metastasis samples. Encapsulation of MDA-MB-231 and MCF7 cells reveals that stiffer matrices promote BC cluster growth and DNA damage, indicated by yH2AX, independent of BC subtype. Moreover, this platform is compatible with patient derived cells, which remain viable for 14 days. These findings underscore the critical role of tissue mechanics in regulating BC metastasis progression and demonstrate the utility of the herein developed tunable, physiologically relevant platform for patient-based models. Table of Content O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=180 SRC="FIGDIR/small/698349v1_ufig1.gif" ALT="Figure 1"> View larger version (59K): org.highwire.dtl.DTLVardef@19a164dorg.highwire.dtl.DTLVardef@12e1c1aorg.highwire.dtl.DTLVardef@371378org.highwire.dtl.DTLVardef@1df3ddb_HPS_FORMAT_FIGEXP M_FIG C_FIG Fabrication of 3D bioengineered breast cancer (BC) lung metastasis niche to investigate how tissue mechanics modulate cancer evolution. Tunable hybrid biomaterials recapitulate the mechanical and biochemical characteristics of healthy soft and diseased stiff lung. Within these niches, stiffness promotes enhanced BC cluster growth and genomic instability. Biocompatibility with patient-derived BC cells, opens opportunities for drug testing platforms for personalized medicine.

bioengineering↗

bioRxiv2025

Stiffness and Viscoelasticity of Adipose Tissue Decellularized Extracellular Matrix Hydrogels Influence Proliferation, Growth Pattern, Migration and Invasion of Breast Cancer Cells

Breast cancer remains the leading cause of cancer-related mortality among women. Cellular behavior is influenced by the physicochemical factors of the extracellular matrix (ECM) surrounding them. In order to model the breast ECM, adipose tissue decellularized extracellular matrix (dECM)-derived hydrogels are generated, which retain the full biochemical complexity of the source tissue, while also exhibiting stiffness and viscoelastic properties comparable to those of breast tissue. By recapitulating the characteristics of their native environment, validated through proteomic analysis and rheology, the poorly metastatic MCF-7 and the highly invasive MDA-MB-231 breast cancer cell lines exhibit their archetypal behaviors within the 3D hydrogels. Moreover, these cells display significantly distinct proliferation, invasion, and growth patterns in hydrogels with different stiffness and viscoelasticity, highlighting the importance of biophysical parameters in modulating cell phenotype. These results illustrate that user-friendly 3D biomaterial models based on adipose tissue dECM can effectively replicate crucial aspects of in vivo cellular behavior. Table of ContentsThis study presents 3D hydrogels derived from porcine adipose tissue dECM that mimic biophysical and biochemical properties of breast tissue. Two breast cancer cell lines mimicking luminal and triple-negative subtypes, exhibited distinct proliferation, migration, and invasion behaviors depending on hydrogel stiffness and viscoelasticity. The results highlight how biophysical cues shape cell phenotype in a user-friendly 3D model. O_FIG O_LINKSMALLFIG WIDTH=179 HEIGHT=200 SRC="FIGDIR/small/693682v1_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@d0216eorg.highwire.dtl.DTLVardef@42c45borg.highwire.dtl.DTLVardef@1693385org.highwire.dtl.DTLVardef@1b598e1_HPS_FORMAT_FIGEXP M_FIG Created with Biorender.com C_FIG

bioengineering↗

bioRxiv2024

Breast cancer cell-derived extracellular vesicles accelerate collagen fibrillogenesis and integrate into the matrix

Extracellular vesicles (EVs) within the extracellular matrix (ECM) are often studied as passive elements whose diffusion and behaviour are subject to the composition and structure of the ECM. While EV diffusion and distribution in tissues are indeed governed by matrix interactions, accumulating evidence suggests that EVs contain much of the cellular machinery required for actively remodeling ECM. Using rheology and confocal reflectance microscopy, we investigate the gelation of collagen I hydrogels formed in the presence of EVs, and show that EVs can play an active role in ECM formation. EVs appear to nucleate new fibrils, recruiting collagen molecules from solution and accelerating their polymerization. Trypsinization of EVs shows that collagen-EV interactions are primarily mediated by surface proteins. The use of extruded plasma membrane vesicles shows that membrane composition determines final fibril length and matrix structure. EVs also become integrated into the fibril structures that they help form, reminiscent of matrix vesicles found in situ within tissues. This represents a plausible way by which EVs are deposited into the ECM, becoming signaling cues for resident cells. Our data show that EV-matrix interactions are dynamic and can contribute to the remodeling of tissue microenvironments. SignificanceExtracellular vesicles (EVs) are nanoscale membrane structures known for their role in facilitating cellto-cell trafficking of proteins, lipids, RNA, and other signaling molecules. In this report, we show that EVs derived from breast cancer cells are not merely passive messengers, but also direct active effectors of extracellular matrix (ECM) remodeling processes. Bulk rheology and confocal microscopy show that these EVs have the ability to nucleate new collagen fibrils and accelerate the formation of dense fibrillar collagenous networks. This has important implications in cancer pathology, where matrix density is often associated with worse disease outcomes, but could also potentially be exploitable in future tissue engineering applications.

biophysics↗

bioRxiv2024

Extracellular vesicle mobility in collagen I hydrogels is modulated by RGD-binding integrins

Extracellular vesicles (EVs) are a diverse population of membrane structures produced and released by cells into the extracellular space for the intercellular trafficking of cargo molecules. They are implicated in various biological processes, including angiogenesis, immunomodulation, and cancer cell signaling. While much research has focused on their biogenesis or their effects on recipient cells, less is understood about how EVs are capable of traversing diverse tissue environments and crossing biological barriers. Their interactions with extracellular matrix components are of particular interest, as such interactions govern diffusivity and mobility, providing a potential basis for organotropism. To start to untangle how EV-matrix interactions affect diffusivity, we use highspeed epifluorescence microscopy, single particle tracking, and confocal reflectance microscopy to analyze particle mobility and localization in extracellular matrix-mimicking hydrogels composed of collagen I. EVs are compared with synthetic liposomes and extruded plasma membrane vesicles to better understand the importance of membrane composition on these interactions. By treating EVs with trypsin to digest surface proteins, we determine that proteins are primarily responsible for EV immobilization in collagen I hydrogels. We next use a synthetic peptide competitive inhibitor to narrow down the identity of the proteins involved to argynylglycylaspartic acid (RGD) motif-binding integrins, which interact with unincorporated or denatured non-fibrillar collagen. Moreover, the effect of integrin inhibition with RGD peptides has strong implications for the use of RGD-peptide-based drugs to treat certain cancers, as integrin inhibition appears to increase EV mobility, improving their ability to infiltrate tissue-like environments.

biophysics↗

bioRxiv2024

3D patterns in alginate hydrogel degradation spatially guide YAP nuclear translocation and hMSC osteogenic differentiation

Tissue engineering involves assembling cells and mimicking the complex anisotropic architecture of biological tissues to perform specific functions. This study explores the impact of patterned hydrogels with anisotropic degradation compared to single-phase materials on the potential of enhancing cell spreading, collective alignment, mechanotransduction and osteogenic differentiation of encapsulated human mesenchymal stromal cells (hMSCs). Spatial patterns of degradable (Deg) and non-degradable (noDeg) subregions are formed by photolithography: UV-triggered thiol-ene crosslinking with matrix metalloprotease (MMP) sensitive peptides form Deg phases, while non-UV exposed regions result in Diels-Alder spontaneous click crosslinking and noDeg phases. 3D patterns in hydrogel degradation enhance hMSC spreading and allow collective cell alignment in Deg areas, while cells remain rounded with no alignment in noDeg regions. In addition, we observe a boosted osteogenic differentiation when compared to single-phase materials, as mid osteogenic markers (osteocalcin) are expressed at day 14 in anisotropic gels, whereas in single-phase only early osteogenic markers are found (osterix). Mechanosensing pathways were evaluated using the expression and localization of YAP. Deg sections in patterned materials have an enhanced nuclear translocation and higher YAP expression compared to single-phase Deg materials and noDeg sections. This effect is lost and no patterns in YAP expression and localization emerge when using an MMP-scramble peptide or no-RGD materials. These findings demonstrate that 3D patterns in alginate hydrogel degradation guide hMSC spreading, collective alignment, enhance YAP nuclear translocation and osteogenic differentiation. Mimicking tissue anisotropy in 3D patterned hydrogels could have broad applications in biofabrication and tissue engineering. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=79 SRC="FIGDIR/small/588803v3_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@f7aa3aorg.highwire.dtl.DTLVardef@1c8d2a4org.highwire.dtl.DTLVardef@17d2371org.highwire.dtl.DTLVardef@a1d6a2_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical AbstractC_FLOATNO C_FIG

bioengineering↗

bioRxiv2023

Phase diagrams of bone remodeling using a 3D stochastic cellular automaton

We propose a 3D stochastic cellular automaton model, governed by evolutionary game theory, to simulate bone remodeling dynamics. The model includes four voxel states: Formation, Quiescence, Resorption, and Environment. We simulate the Resorption and Formation processes on separate time scales to explore the parameter space and derive a phase diagram that illustrates the sensitivity of these processes to parameter changes. Combining these results, we simulate a full bone remodeling cycle. Furthermore, we show the importance of modeling small neighborhoods for studying local bone microenvironment controls. This model can guide experimental design and, in combination with other models, it could assist to further explore external impacts on bone remodeling. Consequently, this model contributes to an improved understanding of complex dynamics in bone remodeling dynamics and exploring alterations due to disease or drug treatment. Author summaryFunctional well-balanced bone remodeling is crucial for a healthy skeleton. Understanding the various causes for the disruption of this complex process requires models that combine behavior on micro- and macro-level. We propose a 3D stochastic cellular automaton model, where each voxel can take one of four different states representing phases of bone remodeling: Formation, Quiescence, Resorption and Environment. With a qualitative analysis, we show how and when small changes in key interaction parameters can make the difference between healthy and pathological bone remodeling. We also highlight the importance of spatial modeling and the size of the neighborhood for investigating local mechanisms. Our proposed model opens the window to explore the complex interplay of factors essential for healthy bone remodeling and potential alterations due to disease or drug treatment. In the long term this could help with the development of new treatment options for bone diseases.

systems biology↗

bioRxiv2023

Aging impairs muscle regeneration by desynchronizing matrix mechano-signaling and macrophage immunomodulation via fibro-adipogenic progenitors

Skeletal muscle regeneration depends on the function of fibro/adipogenic progenitors (FAPs). Here we show that aging impairs myogenic stem cells by disrupting the integration of extracellular matrix and immunomodulatory functions within the stem cell niche, thereby promoting fibro/fatty degeneration. We identify the FAP-secreted protein Periostin as a niche factor that is decreased in aged muscle and in circulation of aged humans with low-exercise lifestyle. Periostin controls FAP-expansion after injury and its depletion fate-regulates FAPs towards adipogenesis. This leads to delayed pro- to anti-inflammatory macrophage transition during regeneration. Transplantation of young FAPs with high Periostin secretion, but not Periostin-deficient FAPs, into aged muscle restores inflammation resolution and successful regeneration. Mechanistically, Periostin activates Focal adhesion kinase- and AKT-signaling in macrophages via integrins to promote an anti-inflammatory profile, which synchronizes matrix-derived mechanosensory signaling and immunomodulation. These results uncover a novel role of FAP-based regulation that orchestrates successful muscle regeneration and prevents fibro/fatty degeneration.

physiology↗

bioRxiv2023

3D osteocyte lacunar morphometry of human bone biopsies with high resolution microCT: from monoclonal gammopathy to newly diagnosed multiple myeloma

Osteocytes are mechanosensitive, bone-embedded cells which are connected via dendrites in a lacuno-canalicular network and regulate bone resorption and formation balance. Alterations in osteocyte lacunar volume, shape and density have been identified in conditions of aging, osteoporosis and osteolytic bone metastasis, indicating patterns of impaired bone remodeling, osteolysis and disease progression. Osteolytic bone disease is a hallmark of the hematologic malignancy multiple myeloma (MM), in which monoclonal plasma cells in the bone marrow disrupt the bone homeostasis and induce excessive resorption at local and distant sites. Qualitative and quantitative changes in the 3D osteocyte lacunar morphometry have not yet been evaluated in MM, nor in the precursor conditions monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM). In this study, we characterized the osteocyte lacunar morphology in trabecular bone of the iliac crest at the ultrastructural level using high resolution microCT in human bone biopsy samples of three MGUS, two SMM and six newly diagnosed MM. In MGUS, SMM and MM we found a trend for lower lacunar density and a shift towards larger lacunae with disease progression (higher 50% cutoff of the lacunar volume cumulative distribution) in the small osteocyte lacunae 20-900 m3 range compared to control samples. In the larger lacunae 900-3000 m3 range, we detected significantly higher lacunar density and microporosity in the MM group compared to the MGUS/SMM group. Regarding the shape distribution, the MGUS/SMM group showed a trend for flatter, more elongated and anisotropic osteocyte lacunae compared to the control group. Altogether, our findings suggest that osteocytes in human MM bone disease undergo changes in their lacunae density, volume and shape, which could be an indicator for osteolysis and disease progression. Future studies are needed to understand whether alterations of the lacunae architecture affect the mechanoresponsiveness of osteocytes and ultimately bone adaptation and fracture resistance in MM and its precursors conditions.

bioengineering↗

bioRxiv2023

Non-specific membrane-matrix interactions influence diffusivity of lipid vesicles in hydrogel environments

The diffusion of extracellular vesicles and liposomes in vivo is affected by different tissue environmental conditions and is of great interest in the development of liposome-based therapeutics and drug-delivery systems. Here, we use a bottom-up biomi-metic approach to better isolate and study steric and electrostatic interactions and their influence on the diffusivity of synthetic large unilamellar vesicles in hydrogel environments. Single-particle tracking of these extracellular vesicle-like particles in agarose hydrogels as an extracellular matrix model shows that membrane deformability and surface charge affect the hydrogel pore spaces that vesicles have access to, which determines overall diffusivity. Moreover, we show that passivation of vesicles with PEGylated lipids, as often used in drug delivery systems enhances diffusivity, but that this effect cannot be fully explained with electrostatic interactions alone. Finally, we compare our experimental findings with existing computational and theoretical work in the field to help explain the non-specific interactions between diffusing particles and gel matrix environments. Statement of SignificanceThe diffusion of nanoparticles in human tissues is dependent on interactions with the surrounding environment. This has wide implications for the development of nanoparticle-based therapeutics and drug delivery systems. Studying these interactions in human tissues and even in model hydrogels composed of reconstituted tissue components can be hampered by the many different complex interactions that can occur. By using a bio-inert hydrogel material like agarose, we remove the influence of specific biochemical interactions, allowing the study of how particle diffusion can be tuned with simple material properties like charge and rigidity. Taking advantage of these non-specific interactions, nanoparticles could one day be engineered to target specific organs by optimizing diffusion in certain tissue environments or retention and immobilization in others.

biophysics↗

bioRxiv2023

Hydrogels with stiffness-degradation spatial patterns control anisotropic 3D cell response

In nature, tissues are patterned, but most biomaterials used in human applications are not. Patterned biomaterials offer the opportunity to mimic spatially segregating biophysical and biochemical properties found in nature. Engineering such properties allows to study cell-matrix interactions in anisotropic matrices in great detail. Here, we developed alginate-based hydrogels with patterns in stiffness and degradation, composed of distinct areas of soft non-degradable (Soft-NoDeg) and stiff degradable (Stiff-Deg) material properties. The hydrogels exhibit emerging patterns in stiffness and degradability over time, taking advantage of dual Diels-Alder covalent crosslinking and UV-mediated peptide crosslinking. The materials were mechanically characterized using rheology for single-phase and surface micro-indentation for patterned materials. 3D encapsulated mouse embryonic fibroblasts (MEFs) allowed to characterize the anisotropic cell-matrix interaction in terms of cell morphology by employing a novel image-based quantification tool. Live/dead staining showed no differences in cell viability but distinct patterns in proliferation, with higher cell number in Stiff-Deg materials at day 14. Patterns of projected cell area became visible already at day 1, with larger values in Soft-NoDeg materials. This was inverted at day 14, when larger projected cell areas were identified in Stiff-Deg. This shift was accompanied by a significant decrease in cell circularity in Stiff-Deg. The control of anisotropic cell morphology by the material patterns was also confirmed by a significant increase in filopodia number and length in Stiff-Deg materials. The novel image-based quantification tool was useful to spatially visualize and quantify the anisotropic cell response in 3D hydrogels with stiffness-degradation spatial patterns. Our results show that patterning of stiffness and degradability allows to control cell anisotropic response in 3D and can be quantified by image-based strategies. This allows a deeper understanding of cell-matrix interactions in a multicomponent material.

bioengineering↗

bioRxiv2023

From breast cancer cell homing to the onset of early bone metastasis: dynamic bone (re)modeling as a driver of osteolytic disease

Breast cancer often metastasizes to bone causing osteolytic lesions. Structural and biophysical changes are rarely studied, yet are hypothesized to influence metastatic progression. Here, we developed a mouse model of early bone metastasis and multimodal 3D imaging to quantify cancer cell homing, dynamic bone (re)modeling and onset of bone metastasis. Using 3D light sheet fluorescence microscopy, we show eGFP+ cancer cells and small clusters in 3D (intact) bones. We detect early bone lesions using time-lapse in vivo microCT and reveal altered bone (re)modeling in absence of detectable lesions. With a new microCT image analysis tool, we detect and track the growth of early bone lesions over time. We show that cancer cells home in all bone compartments, while osteolytic lesions are only detected in the metaphysis, a region of high (re)modeling. Our study provides novel insights of dynamic bone (re)modeling as a driver during the early phase of metastasis.

bioengineering↗

bioRxiv2023

Quiescence-inducing 3D-engineered matrix uncovers mechanosensitive and drug protective FHL2-p21 signaling axis

Resected tumors frequently relapse with distant metastasis, despite systemic treatment. Cellular dormancy has been identified as an important mechanism underlying such drug resistance enabling late relapse. Nonetheless, hurdles associated with detection and isolation of disseminated cancer cells (DCCs) in disease-free patients urge the need for in vitro models of dormant cells suited for drug discovery. Here, we explore dormancy-inducing 3D-engineered matrices, which generate mechanical confinement and induce growth arrest and survival against chemotherapy in cancer cells. We characterized the dormant phenotype of solitary cells by P-ERKlow:P-p38high dormancy signaling ratio, along with Ki67-expression. As underlying mechanism, we identified stiffness-dependent nuclear localization of the four-and-a-half LIM domains 2 (FHL2) protein, leading to p53-independent high p21Cip1/Waf1 nuclear expression, validated in murine and human tissue. Suggestive of a resistance-causing role, cells in the dormancy-inducing matrix became sensitive against chemotherapy upon FHL2 downregulation. Thus, our biomaterial-based approach will enable systematic screens for novel compounds suited to eradicate potentially relapsing, dormant cancer cells. TeaserUsing semi-synthetic bioengineered hydrogels, we reveal a mechanosensitive and drug protective mechanism of dormant cancer cells in tissues

bioengineering↗