Biology subjects

Logue, J. S.

Publications and source records attributed to Logue, J. S..

9 recordsLinked to original sources

bioRxiv2026

Serotonin Receptor Signaling Promotes Amoeboid Migration of Melanoma Cells Through cAMP/PKA Activation

Melanoma cells frequently utilize bleb-driven amoeboid migration to navigate confined microenvironments during metastasis. Through a morphology-based drug repurposing screen, we identified the anti-migraine medication dihydroergotamine (DHE) as a potent inhibitor of this behavior. We show that DHE suppresses amoeboid motility by targeting serotonin receptors, primarily 5-HTR7. Trace levels of peripheral serotonin activates 5-HTR7, which in turn stimulates cAMP/PKA and ROCK signaling. This signaling cascade increases the cortical contractility necessary to sustain blebbing. Accordingly, DHE treatment or PKA inhibition significantly impairs confined migration without altering cell proliferation. Clinically, elevated levels of serotonin-degrading enzymes, such as MAOB, correlate with favorable patient prognoses and are reduced in metastatic lesions. Ultimately, these findings reveal an unanticipated role for peripheral serotonin in melanoma biomechanics and highlight serotonin receptors as highly actionable targets to limit metastatic dissemination. Significance StatementMetastasis is the leading cause of melanoma-related mortality, driven in part by the ability of tumor cells to adopt a highly contractile amoeboid mode of migration that enables movement through spatially confined tissues. This study uncovers a previously unrecognized mechanobiological role for peripheral serotonin in promoting this invasive behavior. We show that low concentrations of serotonin activate cAMP/PKA signaling to generate the actomyosin contractility required for amoeboid migration. Importantly, the FDA-approved migraine drug dihydroergotamine (DHE) blocks this pathway and significantly inhibits cancer cell motility. Supported by patient data linking reduced serotonin degradation with increased metastatic progression, these findings identify serotonin signaling as a novel driver of melanoma dissemination and provide a compelling rationale for repurposing serotonin-targeting therapeutics to prevent metastatic spread.

cancer biology↗

bioRxiv2025

Targeting Cholesterol-Dependent Piezo1 Activation Impairs Amoeboid Migration in Melanoma Cells

Bleb-based migration enables cancer cells to navigate the heterogeneous tumor microenvironment. Here, we report a phenotypic screen identifying drugs that inhibit bleb formation, a driver of amoeboid migration. Statins, including Fluvastatin and Pitavastatin, suppress amoeboid migration of melanoma cells in confined environments by reducing intracellular cholesterol. This disrupts plasma membrane tension sensing by Piezo1, lowering intracellular Ca2+ levels. Both cholesterol supplementation and Piezo1 activation rescue migration in confined environments, confirming their functional link. Notably, high cholesterol biosynthesis enzyme levels correlate with reduced patient survival in melanoma. These findings reveal that cholesterol is essential for confinement sensing through Piezo1, identifying cholesterol biosynthesis or uptake as rational therapeutic targets against metastasis. Significance StatementThis study builds on a phenotypic drug screen that identified statins as inhibitors of bleb-based migration, a key mode of cancer cell movement through confined spaces. We show that statins reduce membrane cholesterol, disrupting the function of the mechanosensitive channel Piezo1 and impairing melanoma cell migration. Restoring cholesterol or activating Piezo1 rescues this effect, revealing a functional link between cholesterol and confinement sensing. Our findings highlight cholesterol biosynthesis as essential for invasive cell behavior and identify it as a therapeutic vulnerability. Importantly, elevated cholesterol pathway activity correlates with reduced survival in melanoma patients, underscoring the clinical relevance of targeting this pathway to limit metastasis.

cancer biology↗

bioRxiv2023

The amoeboid migration of monocytes in confining channels requires the local remodeling of the cortical actin cytoskeleton by cofilin-1

Within the bloodstream, monocytes must traverse the microvasculature to prevent leukostasis, which is the entrapment of monocytes within the confines of the microvasculature. Using the model cell line, THP-1, and VCAM-1 coated channels to simulate the microvasculature surface, we demonstrate that monocytes predominantly adopt an amoeboid phenotype, which is characterized by the formation of blebs. As opposed to cortical actin flow in leader blebs, cell movement is correlated with myosin contraction at the cell rear. It was previously documented that cofilin-1 promotes cortical actin turnover at leader bleb necks in melanoma cells. In monocytes, our data suggest that cofilin-1 promotes the local upregulation of myosin contractility through actin cytoskeleton remodeling. In support of this concept, cofilin-1 is found to localize to a single cell edge. Moreover, the widespread upregulation of myosin contractility was found to inhibit migration. Thus, monocytes within the microvasculature may avoid entrapment by adopting an amoeboid mode of migration. Summary StatementIn confining channels, monocytes largely adopt an amoeboid migrating phenotype, which is found to depend on the upregulation of myosin contractility at the cell rear and cortical actin remodeling by cofilin-1.

cell biology↗

bioRxiv2023

Piezo1 conspires with INF2 to promote amoeboid migration in confined environments

To invade heterogenous tissues, transformed cells may undergo a mesenchymal to amoeboid transition (MAT). However, the molecular mechanisms regulating this transition are poorly defined. In invasive melanoma cells, we demonstrate that intracellular [Ca2+] increases with the degree of confinement in a Piezo1 dependent fashion. Moreover, Piezo1/Ca2+ is found to drive amoeboid and not mesenchymal migration in confined environments. Consistent with a model in which Piezo1 senses tension at the plasma membrane, the percentage of cells using amoeboid migration is further increased in undulating microchannels. Surprisingly, amoeboid migration was not promoted by myosin light chain kinase (MLCK), which is sensitive to intracellular [Ca2+]. Instead, we report that Piezo1/Ca2+ activates inverted formin-2 (INF2) to induce widespread actin cytoskeletal remodeling. Strikingly, the activation of INF2 is found to promote de-adhesion, which in turn facilitates MAT. Using micropatterned surfaces, we demonstrate that cells require INF2 to effectively migrate in environments with challenging mechanochemical properties. Summary StatementMigrating melanoma cells are found to rely on the activation of inverted formin-2 (INF2) by Piezo1/Ca2+ for mesenchymal to amoeboid transition (MAT) in confined environments.

cell biology↗

bioRxiv2021

A novel Fiji/ImageJ-based macro identifies the limitations of F-actin markers in studying the fast amoeboid migration of confined cells

When confined, cells have recently been shown to undergo a phenotypic switch to what has been termed, fast amoeboid (leader bleb-based) migration. However, as this is a nascent area of research, few tools are available for the rapid analysis of cell behavior. Here, we demonstrate that a novel Fiji/ImageJ-based plugin, Analyze_Blebs, can be used to quickly obtain cell migration parameters and morphometrics from time lapse images. As validation, we show that Analyze_Blebs can detect significant differences in cell migration and morphometrics, such as the largest bleb size, upon introducing different live markers of F-actin, including F-tractin and LifeAct tagged with green and red fluorescent proteins. We also demonstrate, using flow cytometry, that live markers increase total levels of F-actin. Furthermore, that F-tractin increases cell stiffness, which was found to correlate with a decrease in migration, thus reaffirming the importance of cell mechanics as a determinant of Leader Bleb-Based Migration (LBBM). Highlight summaryA new plugin, Analyze_Blebs, enables the rapid analysis of cell migration and morphometrics of fast amoeboid cells. Morphometrics combined with cell stiffness are found to be predictive of confined, fast amoeboid (leader bleb-based), migration.

cell biology↗

bioRxiv2021

Melanoma cells adopt features of both mesenchymal and amoeboid migration within confining channels

For metastasis to occur, cancer cells must traverse a range of tissue environments. In part, this is accomplished by cells adjusting their migration mode to one that is best suited to the environment. Melanoma cells have been shown to be particularly plastic, frequently using both mesenchymal and amoeboid (bleb-based) modes of migration. It has been demonstrated that 2D confinement will promote the transition from mesenchymal to bleb-based migration. However, if melanoma cells similarly transition to bleb-based migration in response to 3D confinement, such as within narrow channels, is unknown. Here, using micro-fabricated channels, we demonstrate that melanoma cells adopt features of both mesenchymal and bleb-based migration. In narrow (8 m; height and width) channels coated with fibronectin, ~50% of melanoma cells were found to use either mesenchymal or bleb-based migration modes. In contrast, the inhibition of Src family kinases or coating channels with BSA, completely eliminated any features of mesenchymal migration. Detailed comparisons of migration parameters revealed that blebbing cells, particularly in the absence of adhesions, were faster than mesenchymal cells. In contrast to what has been previously shown under conditions of 2D confinement, pharmacologically inhibiting Arp2/3 promoted a fast filopodial-based mode of migration. Accordingly, we report that melanoma cells adopt a unique range of phenotypes under conditions of 3D confinement.

cell biology↗

bioRxiv2021

ADF and cofilin-1 collaborate to promote cortical actin flow and the leader bleb-based migration of confined cells

Melanoma cells have been shown to undergo fast amoeboid (leader bleb-based) migration, requiring a single large bleb for migration. In leader blebs, is a rapid flow of cortical actin that drives the cell forward. Using RNAi, we find that co-depleting cofilin-1 and ADF led to a large increase in cortical actin, suggesting that both proteins regulate cortical actin. Furthermore, severing factors can promote contractility through the regulation of actin architecture. However, RNAi of cofilin-1 but not ADF led to a significant decrease in cell stiffness. We found cofilin-1 to be enriched at leader bleb necks, whereas RNAi of cofilin-1 and ADF reduced bleb sizes and the frequency of motile cells. Strikingly, cells without cofilin-1 and ADF had blebs with abnormally long necks. Many of these blebs failed to retract and displayed slow actin turnover. Collectively, our data identifies cofilin-1 and ADF as actin remodeling factors required for fast amoeboid migration.

cell biology↗

bioRxiv2020

Emerin regulation of nuclear stiffness is required for the amoeboid migration of cancer cells in confining environments

When metastasizing, tumor cells must traverse environments with diverse physicochemical properties. Recently, the cell nucleus has emerged as a major regulator of the transition from mesenchymal to fast amoeboid (leader bleb-based) migration. Here, in melanoma cells, we demonstrate that increasing nuclear stiffness through elevating Lamin A, inhibits fast amoeboid migration. Importantly, nuclei may respond to force through stiffening. A key factor in this process is the inner nuclear membrane (INM) protein, emerin. Accordingly, we determined the role of emerin in regulating fast amoeboid migration. Strikingly, we found that both the up- and down-regulation of emerin results in an inhibition of fast amoeboid migration. However, when key Src phosphorylation sites were removed, up-regulation of emerin no longer inhibited fast amoeboid migration. Interestingly, in confined cells, Src activity was low, as measured by a Src biosensor. Thus, the fast amoeboid migration of melanoma cells depends on the precise calibration of emerin activity. Summary StatementIn mechanically constrictive microenvironments, amoeboid migrating melanoma cells require emerin for the precise calibration of nuclear stiffness.

cell biology↗

bioRxiv2019

A flexible network of Vimentin intermediate filaments promotes the migration of amoeboid cancer cells through confined environments

The spread of tumor cells to distant sites is promoted by their ability to switch between mesenchymal and amoeboid (bleb-based) migration. Because of this, inhibitors of metastasis must account for each motility mode. To this end, here we determine the precise role of the Vimentin intermediate filament system in regulating the migration of amoeboid human cancer cells. Vimentin is a classic marker of epithelial to mesenchymal transition and is therefore, an ideal target for a metastasis inhibitor. However, the role of Vimentin in amoeboid migration has not been determined. Since amoeboid, leader bleb-based migration occurs in confined spaces and Vimentin is known to be a major determinant of cell mechanical properties, we hypothesized that a flexible Vimentin network is required for fast amoeboid migration. This was tested using our PDMS slab-based approach for the confinement of cells, RNAi, over-expression, pharmacological treatments, and measurements of cell stiffness. In contrast to Vimentin RNAi, inducing the bundling of Vimentin was found to inhibit fast amoeboid migration and proliferation. Importantly, these effects were independent of changes in actomyosin contractility. Collectively, our data supports a model whereby the perturbation of cell mechanical properties by Vimentin bundling inhibits the invasive properties of cancer cells.

cell biology↗