Epithelial-mesenchymal transition (EMT) is a crucial event in tumor invasion and metastasis. However, most of past EMT studies have been conducted in the conventional two-dimensional (2D) monolayer culture. Therefore, it remains unclear what invasive phenotypes are acquired by EMT-induced cancer cells. To address this point, we attempted to characterize EMT cells in more physiological, three-di...

We propose two terahertz reflectometry modalities which are optimized to be sensitive to the curvature of surface features. The first is a dark-field technique which allows to detect protrusions and dents on surfaces with high sensitivity. It cannot distinguish, however, between convex and concave shape. This becomes possible with the second technique, which combines out-of-focus imaging with s...

One of the important clinical features to differentiate benign melanocytic nevi from malignant melanomas is the irregularity of the lesion border. A careful examination of a lesion border reveals two types of irregularity: texture irregularity and structure irregularity. Texture irregularities are the small variations along the border, while structure irregularities are the global indentations ...

The p21-activated kinase (PAK) 1 kinase, an effector of the Cdc42 and Rac1 GTPases, regulates cell protrusions and motility by controlling actin and adhesion dynamics. Its deregulation has been linked to human cancer. We show here that activation of PAK1 is necessary for protrusive activity during cell spreading. To investigate PAK1 activation dynamics at live protrusions, we developed a confor...

Dendritic protrusions (spines and filopodia) are structural indicators of synapses that have been linked to neuronal learning and memory through their morphological alterations induced by development and experienced-dependent activities. Although previous studies have demonstrated that depriving sensory experience leads to structural changes in neocortical organization, the more subtle effects ...

Development and remodeling of synaptic networks occurs through a continuous turnover of dendritic spines. However, the mechanisms that regulate the formation and stabilization of newly formed spines remain poorly understood. Here, we applied repetitive confocal imaging to hippocampal slice cultures to address these issues. We find that, although the turnover rate of protrusions progressively de...

Several bacterial pathogens, including Listeria monocytogenes, Shigella flexneri and Rickettsia spp., have evolved mechanisms to actively spread within human tissues. Spreading is initiated by the pathogen-induced recruitment of host filamentous (F)-actin. F-actin forms a tail behind the microbe, propelling it through the cytoplasm. The motile pathogen then encounters the host plasma membrane, ...

The development of luminal organs begins with the formation of spherical cysts composed of a single layer of epithelial cells. Using a model three-dimensional cell culture, this study examines the role of a cytoskeletal motor, myosin II, in cyst formation. Caco-2 and SK-CO15 intestinal epithelial cells were embedded into Matrigel, and myosin II was inhibited by blebbistatin or siRNA-mediated kn...

Myosin I is present in Swiss 3T3 fibroblasts and its localization reflects a possible involvement in the extension and/or retraction of protrusions at the leading edge of locomoting cells and the transport of vesicles, but not in the contraction of stress fibers or transverse fibers. An affinity-purified polyclonal antibody to brush border myosin I colocalizes with a polypeptide of 120 kD in fi...