Displacement correlations between a single mesenchymal-like cell and its nucleus effectively link subcellular activities and motility in cell migration analysis

Unraveling Endothelial Cell Migration: Insights into Fundamental Forces, Inflammation, Biomaterial Applications, and Tissue Regeneration Strategies

Cell migration is vital for many fundamental biological processes and human pathologies throughout our life. Dynamic molecular changes in the tissue microenvironment determine modifications of cell movement, which can be reflected either individually or collectively. Endothelial cell (EC) migratory adaptation occurs during several events and phenomena, such as endothelial injury, vasculogenesis, and angiogenesis, under both normal and highly inflammatory conditions. Several advantageous processes can be supported by biomaterials. Endothelial cells are used in combination with various types of biomaterials to design scaffolds promoting the formation of mature blood vessels within tissue engineered structures. Appropriate selection, in terms of scaffolding properties, can promote desirable cell behavior to varying degrees. An increasing amount of research could lead to the creation of the perfect biomaterial for regenerative medicine applications. In this review, we summarize the state of knowledge regarding the possible systems by which inflammation may influence endothelial cell migration. We also describe the fundamental forces governing cell motility with a specific focus on ECs. Additionally, we discuss the biomaterials used for EC culture, which serve to enhance the proliferative, proangiogenic, and promigratory potential of cells. Moreover, we introduce the mechanisms of cell movement and highlight the significance of understanding these mechanisms in the context of designing scaffolds that promote tissue regeneration.

Decomposition of cell activities revealing the role of the cell cycle in driving biofunctional heterogeneity

Heterogeneity of cell phenotypes remains a barrier in progressing cell research and a challenge in conquering cancer-related drug resistance. Cell morphology, the most direct property of cell phenotype, evolves along the progression of the cell cycle; meanwhile, cell motility, the dynamic property of cell phenotype, also alters over the cell cycle. However, a quantifiable research understanding the relationship between the cell cycle and cell migration is missing. Herein, we coordinate the migratory behaviours of NIH 3T3 fibroblasts to their corresponding phases of the cell cycle, the G1, the S, and the G2 phases, and explain the relationship through the spatiotemporal arrangements between the Rho GTPases’ signals and cyclin-dependent kinase inhibitors, p21^Cip1, and p27^Kip1. Taken together, we demonstrate that both cell morphology and the dynamic subcellular behaviour are homogenous within each stage of the cell cycle phases but heterogenous between phases through quantitative cell analyses and an interactive molecular mechanism between the cell cycle and cell migration, posing potential implications in countering drug resistance.

Kalirin-RAC controls nucleokinetic migration in ADRN-type neuroblastoma

The migrational propensity of neuroblastoma is affected by cell identity, but the mechanisms behind the divergence remain unknown. Using RNAi and time-lapse imaging, we show that ADRN-type NB cells exhibit RAC1- and kalirin-dependent nucleokinetic (NUC) migration that relies on several integral components of neuronal migration. Inhibition of NUC migration by RAC1 and kalirin-GEF1 inhibitors occurs without hampering cell proliferation and ADRN identity. Using three clinically relevant expression dichotomies, we reveal that most of up-regulated mRNAs in RAC1- and kalirin-GEF1-suppressed ADRN-type NB cells are associated with low-risk characteristics. The computational analysis shows that, in a context of overall gene set poverty, the upregulomes in RAC1- and kalirin-GEF1-suppressed ADRN-type cells are a batch of AU-rich element-containing mRNAs, which suggests a link between NUC migration and mRNA stability. Gene set enrichment analysis-based search for vulnerabilities reveals prospective weak points in RAC1- and kalirin-GEF1-suppressed ADRN-type NB cells, including activities of H3K27- and DNA methyltransferases. Altogether, these data support the introduction of NUC inhibitors into cancer treatment research.

Intratumoral heterogeneity of endogenous tumor cell invasive behavior in human glioblastoma

Intratumoral genetic heterogeneity is a widely accepted characteristic of human cancer, including the most common primary malignant brain tumor, glioblastoma. However, the variability in biological behaviors amongst cells within individual tumors is not well described. Invasion into unaffected brain parenchyma is one such behavior, and a leading mechanism of tumor recurrence unaddressed by the current therapeutic armamentarium. Further, providing insight into variability of tumor cell migration within individual tumors may inform discovery of novel anti-invasive therapeutics. In this study, ex vivo organotypic slice cultures from EGFR-wild type and EGFR-amplified patient tumors were treated with the EGFR inhibitor gefitinib to evaluate potential sub-population restricted intratumoral drug-specific responses. High-resolution time-lapse microscopy and quantitative path tracking demonstrated migration of individual cells are punctuated by intermittent bursts of movement. Elevation of population aggregate mean speeds were driven by subpopulations of cells exhibiting frequent high-amplitude bursts, enriched within EGFR-amplified tumors. Treatment with gefitinib specifically targeted high-burst cell subpopulations only in EGFR-amplified tumors, decreasing bursting frequency and amplitude. We provide evidence of intratumoral subpopulations of cells with enhanced migratory behavior in human glioblastoma, selectively targeted via EGFR inhibition. These data justify use of direct human tumor slice cultures to investigate patient-specific therapies designed to limit tumor invasion.

Integrating transient cellular and nuclear motions to comprehensively describe cell migration patterns

Various subcellular activities, such as protrusion and detachment, compose a cell migration process. The molecular mechanisms of these subcellular activities have been elucidated. However, there is no method that can assess the contributions of these subcellular activities to the global cell migration pattern of a given cell type. Hence, we develop a powerful approach based on CN correlations that quantitatively profiles the cell migration pattern of a given cell type in terms of assembled subcellular activities. In this way, we bridge migration data at the cellular level with underlying molecular mechanisms. The CN correlation profile is found to uniquely and consistently represent the cell migration pattern of each cell type probed. It can clearly reveal the effects of molecular perturbations, such as Y27632 and Cdc42 knockdown on each subcellular migratory activity. As a result, the CN correlation approach serves as a cell dynamic descriptor that can extract comprehensive quantitative data from cell migration movies for integrative biological analyses.