A biomechanical model for the transendothelial migration of cancer cells

Unravelling cell migration: defining movement from the cell surface

Cell motility is essential for life and development. Unfortunately, cell migration is also linked to several pathological processes, such as cancer metastasis. Cells' ability to migrate relies on many actors. Cells change their migratory strategy based on their phenotype and the properties of the surrounding microenvironment. Cell migration is, therefore, an extremely complex phenomenon. Researchers have investigated cell motility for more than a century. Recent discoveries have uncovered some of the mysteries associated with the mechanisms involved in cell migration, such as intracellular signaling and cell mechanics. These findings involve different players, including transmembrane receptors, adhesive complexes, cytoskeletal components , the nucleus, and the extracellular matrix. This review aims to give a global overview of our current understanding of cell migration.

Magnetic torque–driven living microrobots for increased tumor infiltration

Biohybrid bacteria–based microrobots are increasingly recognized as promising externally controllable vehicles for targeted cancer therapy. Magnetic fields in particular have been used as a safe means to transfer energy and direct their motion. Thus far, the magnetic control strategies used in this context rely on poorly scalable magnetic field gradients, require active position feedback, or are ill-suited to diffuse distributions within the body. Here, we present a magnetic torque–driven control scheme for enhanced transport through biological barriers that complements the innate taxis toward tumor cores exhibited by a range of bacteria, shown for Magnetospirillum magneticum as a magnetically responsive model organism. This hybrid control strategy is readily scalable, independent of position feedback, and applicable to bacterial microrobots dispersed by the circulatory system. We observed a fourfold increase in translocation of magnetically responsive bacteria across a model of the vascular endothelium and found that the primary mechanism driving increased transport is torque-driven surface exploration at the cell interface. Using spheroids as a three-dimensional tumor model, fluorescently labeled bacteria colonized their core regions with up to 21-fold higher signal in samples exposed to rotating magnetic fields. In addition to enhanced transport, we demonstrated that our control scheme offers further advantages, including the possibility for closed-loop optimization based on inductive detection, as well as spatially selective actuation to reduce off-target effects. Last, after systemic intravenous injection in mice, we showed significantly increased bacterial tumor accumulation, supporting the feasibility of deploying this control scheme clinically for magnetically responsive biohybrid microrobots.

Tools for computational analysis of moving boundary problems in cellular mechanobiology

A cell's ability to change shape is one of the most fundamental biological processes and is essential for maintaining healthy organisms. When the ability to control shape goes awry, it often results in a diseased system. As such, it is important to understand the mechanisms that allow a cell to sense and respond to its environment so as to maintain cellular shape homeostasis. Because of the inherent complexity of the system, computational models that are based on sound theoretical understanding of the biochemistry and biomechanics and that use experimentally measured parameters are an essential tool. These models involve an inherent feedback, whereby shape is determined by the action of regulatory signals whose spatial distribution depends on the shape. To carry out computational simulations of these moving boundary problems requires special computational techniques. A variety of alternative approaches, depending on the type and scale of question being asked, have been used to simulate various biological processes, including cell motility, division, mechanosensation, and cell engulfment. In general, these models consider the forces that act on the system (both internally generated, or externally imposed) and the mechanical properties of the cell that resist these forces. Moving forward, making these techniques more accessible to the non-expert will help improve interdisciplinary research thereby providing new insight into important biological processes that affect human health. This article is categorized under: Cancer > Cancer>Computational Models Cancer > Cancer>Molecular and Cellular Physiology.

The apoptotic effect of GSK-3 inhibitors: BIO and CHIR 98014 on H1975 lung cancer cells through ROS generation and mitochondrial dysfunction

OBJECTIVE

GSK-3 has been reported to be upregulated in malignant diseases, including lung cancers, thus suggesting it to be a valid target for cancer treatment. The study elucidates the possible mechanism involved in the ability of GSK-3 inhibitors: BIO and CHIR 98014 to regulate proteins involved in cell death of H1975 lung cancer cells.

RESULTS

BIO and CHIR 98014 successfully induced apoptosis at lower concentrations in H1975 cells but not in H460 lung cancer cells. Moreover, increased ROS generation and depolarization of mitochondrial membrane potential were observed in both treatments. Cleavage of caspase-3 was observed in both BIO and CHIR 98014-treated cells after 72 h with monolayer and tumorsphere cell culture models.

CONCLUSIONS

The use of GSK-3 inhibitors shows promising apoptotic abilities in clinical cancer treatments, particularly for lung cancer cells. This study is the first report to describe the significant apoptotic effects of BIO and CHIR 98014 through multiple mechanisms of H1975 NSCLC that are linked to their proliferative and migratory capacities.