Biology subjects

Aime, C.

Publications and source records attributed to Aime, C..

7 recordsLinked to original sources

bioRxiv2025

The extracellular matrix dictates ovarian cancer cell migration in an in vivo-derived circulating environment

Ovarian cancer (OC) disseminates via ascites and interaction with peritoneal extracellular matrix (ECM). To dissect the crosstalk between ECM and ascites in OC cell migration, we developed an ovarian tumor-on-chip integrating OC tumor spheroids, perfusion-induced shear stress of fluid supplemented with key components of ascites or patient-derived ascites, and biomimetic ECMs mimicking either early-stage basement membrane or late-stage connective tissues. We evaluated the individual and combined effects of two key ascitic components, fibronectin and TGF-{beta}, and compared these results with the perfusion of patient ascites. Results showed that cell migration, morphology, and epithelial-to-mesenchymal transition (EMT) markers such as the reorganization of vimentin cytoskeleton depend strongly on ECM composition, regardless of biochemical cues. Fibronectin and TGF-{beta} synergistically enhanced migration and EMT signatures, especially on basement membrane-rich ECM. Patient ascites further promoted migration but did not override ECM-driven migration patterns. Our findings show that clinical ascites perfusion exemplifies the ECM-dependence of cancer cell migration. This highlights that ECM protein composition is a dominant regulator of OC cell migration, providing key insights for in vitro tumor modeling and therapeutic strategies targeting the metastatic microenvironment.

cancer biology↗

bioRxiv2024

Hotwiring integrin endocytosis acutely modulates cell interactions

Integrins are heterodimeric cell surface receptors that govern cell-cell interactions, which in turn can influence multiscale processes: cell migration, extracellular matrix remodeling and tissue formation. These processes occur over timescales which range from milliseconds to days. While various strategies exist to study integrin function across biological scales from cell to tissue, they are often chronic and fail to target specific cell-cell interactions acutely. We engineered cells to rapidly alter cell behavior by downregulating the surface population of 5{beta}1 integrins through hot-wired clathrin-mediated endocytosis. This method allows for inducible, specific internalization of 5{beta}1 integrins, achieving acute downregulation across various cell lines in 5-30 minutes. We show that induced internalization of 5{beta}1 decreases the cell area, causes uptake of extracellular fibronectin, and decreases the rate of tumor spheroid compaction. This targeted control of multiscale processes by rapid downregulation of this important class of cell surface receptors demonstrates that hot-wired endocytosis is a useful tool to acutely modulate cell biology.

bioengineering↗

bioRxiv2023

Phylogenomics, biogeography, and trait evolution of the Boletaceae (Boletales, Agaricomycetes, Basidiomycota)

The species-rich porcini mushroom family Boletaceae is a widespread and well-known group of ectomycorrhizal (ECM) mushroom-forming fungi that has eluded intrafamilial phylogenetic resolution despite many attempts using morphological traits and multi-locus molecular datasets. In this study, we present a genome-wide molecular dataset of 1764 single-copy gene families from a global sampling of 418 Boletaceae specimens. The resulting phylogenetic analysis has strong statistical support for most branches of the tree, including the first statistically robust backbone. The enigmatic Phylloboletellus chloephorus from non-ECM Argentinian subtropical forests was recovered as an early diverging lineage within the Boletaceae. Time-calibrated branch lengths estimate that the family first arose in the early- to mid-Cretaceous and underwent a rapid radiation in the Eocene, possibly when the ECM nutritional mode arose with the emergence and diversification of ECM angiosperms. Biogeographic reconstructions reveal a complex history of vicariance and episodic long-distance dispersal correlated with historical geologic events, including Gondwanan origins and cladogenesis patterns that parallel its fragmentation. Ancestral state reconstruction of sporocarp morphological traits predicts that the ancestor of the Boletaceae was lamellate with ornamented basidiospores, contrary to most contemporary "bolete" morphologies. Transition rates indicated that the lamellate hymenophore and sequestrate sporocarp are reversible traits. Together, this study represents the most comprehensively sampled, data-rich molecular phylogeny of the Boletaceae to date, enabling robust inferences of trait evolution and biogeography in the group.

evolutionary biology↗

bioRxiv2023

The balance between shear flow and extracellular matrix in ovarian cancer-on-chip

Ovarian cancer is the most lethal gynecologic cancer in developed countries. Silent onset of the metastatic activity of ovarian tumor cells is factor for poor outcomes. In the tumor microenvironment, the extracellular matrix (ECM) and flow shear stress are known to play key roles in directing cell invasion. Hence, acute and tunable tools are critical to mimic scaffold and fluid for building clinically relevant in vitro models. We have built an ovarian tumor-on-chip where tunable ECM models are easily seeded with tumor spheroids and integrated within a microfluidic chip. This allows the investigation of the crosstalk between the characteristics of the ECM models and shear stress on the migratory behavior and cellular heterogeneity of ovarian tumor cells. We vary the composition of the ECM playing with type I and IV collagens and laminin, and control the shear stress in the chip. This work shows that in the shear stress regime of the peritoneal cavity, the ECM plays a major role in driving individual or collective modes of migration. In the presence of basement membrane proteins, migration is more collective that on type I collagen regardless of shear stress level. In addition, with increasing shear stress, individual cell migration was enhanced, while no significant impact on collective migration could be measured. This highlights our ability to discriminate relevant parameters for onset and shifts of cell behavior using our in vitro models. Furthermore, we described the ability to shift cells from an epithelial phenotype to a more mesenchymal phenotype, which could allow us to describe the role of these parameters during epithelial-to-mesenchymal (EMT) transition as a continuous process. Finally, we conclude that the ECM should hold a central position in in vitro cancer models, to understand cell response and develop platforms for therapeutic development.

bioengineering↗

bioRxiv2022

Topology of connective tissues: a key parameter in cellular heterogeneity, beyond composition and stiffness

Cellular plasticity is essential in physiological contexts, including pathological ones. It is the basis of morphogenesis and organogenesis, as well as tumorigenesis and metastasis. The extracellular matrix (ECM) is a key player in the generation of cellular heterogeneity. Advances in our understanding of cell plasticity rely on our ability to provide relevant in vitro models. This requires to catch the characteristics of the tissues that are essential for controlling cell fate. To do this, we must consider the diversity of tissues, the diversity of physiological contexts, and the constant remodeling of ECM along these processes. To this aim, we have fabricated a library of ECM models for reproducing the scaffold of connective tissues and basement membrane with different biofabrication routes based on the electrospining and drop casting of biopolymers. Using a combination of multiphoton imaging and nanoindentation, we show that we can vary independently protein composition, topology of connective tissues and stiffness of ECM models. Reproducing the features of a tissue and physiological context in turns allows to generate the complexity of the phenotypic landscape associated with the epithelial-to-mesenchymal transition (EMT) in human ovarian cancer. We show that EMT shift cannot be directly correlated with a unique ECM feature, which reflects the multidimensionality of living environments. Very importantly, our combinatorial approach allows us to provide in vitro models, where the impact of the topological cues on cellular phenotypes can be revealed, beyond protein composition and stiffness of the ECM matrix. On this line, this work is a further step towards the development of ECM models recapitulating the constantly remodeled scaffolding environment that cells face and provides new insights for the development of cell-free matrices.

bioengineering↗

bioRxiv2021

High-throughput tuning of ovarian cancer spheroids for on-chip invasion assays

We developed an invasion assay by using microfabricated culture devices. First, ovarian tumor spheroids were generated with a culture patch device consisting of an agarose membrane formed with a honeycomb microframe - the patch - and gelatin nanofiber backbone. By changing the dimensions of the honeycomb compartments we were able to control the number of cells and size of the spheroids. When the spheroids were placed on a patch coated with a thin membrane of fibrillary type I collagen, spheroid disruption was observed due to substrate induced cell migration. This process is straightforward and should be applicable to other cancer types, as well as assays under microfluidic conditions, thereby holding the potential for use in tumor modeling and anti-cancer drug development.

bioengineering↗

bioRxiv2019

Electrospinning of pure, native, cross-linker free self-supported collagen membrane

Electrospinning (ES) is an extremely promising method for the preparation of self-supported membranes for tissue engineering by mimicking the 3D fibrillar structure of the extracellular matrix. Conflicting results about collagen ES in the literature concern the conditions of collagen solubilization to improve electrospinnability, and the use of co-polymers and chemical cross-linkers to stabilize the structure of collagen membranes. Here we report for the first time (1) the ES of pure and native collagen into a self-supported membrane in absence of polymer support and (2) the preservation of the membrane integrity in hydrated media in absence of crosslinker. We use a multiscale approach to characterize collagen native structure at the molecular level using synchrotron radiation circular dichroism, and to investigate collagen hierarchical organization within the self-supported membrane using electron and multiphoton microscopies. Finally, we show that the membranes are perfectly suited for cell adhesion and spreading, making very promising candidates for the development of advanced biomaterials.

bioengineering↗