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Group Introduction

Cell Mechanics Research Group

Introduction to research

Cytoskeletal systems that include filamentous networks consisting of actin microfilaments, microtubules and intermediate filaments, molecular motors such as myosin and dynein, and adhesive proteins, e.g. integrin, play critical roles in various cellular activities and govern cell properties. For example, nestin, one of the intermediate filaments, plays important and unknown roles in cancer metastasis, suggesting that dynamic changes of cytoskeletal proteins regulate motility and behavior of the cells. We aim to elucidate the unknown functions of those cytoskeletal proteins and contribute to the development of the biomedical field.

Novel cell analysis and manipulation technology using Nanoneedle (Chikashi Nakamura)

Nanoneedle of 200 nm in diameter and 20 μm in length can be inserted into cells with minimal damages. Examples of nanoneedle applications;
*Analysis of mechanical properties of cytoskeletal proteins using AFM cantilever nanoneedle
*High efficiency molecular delivery using nanoneedle array (100,000 needles on 5 mm chip)
*Novel mechanical cell separation by targeting intracellular markers using nanoneedle array.

Analysis of mechanical properties of cytoskeletal proteins

High efficiency molecular delivery using nanoneedle array

High efficiency molecular delivery using nanoneedle array High efficiency molecular delivery using nanoneedle array

Structural and functional studies of the motile mechanisms of molecular motor proteins (Keiko Hirose)

Dynein is a molecular motor that powers the motility of cilia and flagella. To understand the molecular mechanism of force production by dynein, we are developing model systems in which the dynein-microtubule complex is cross-linked with DNA-origami structures. We are analyzing their motility by optical trap nanometry, and studying the structures of force-producing dynein molecules by electron microscopy.

Structural and functional studies of the motile mechanisms of molecular motor proteins

Free Surface Cell Biology (Kouichi Tachibana)

We have found that loss of adhesion induces phosphorylation of ERM proteins, which leads to actin reorganization and changes in cell shapes. Meanwhile, dephosphorylation of phosphorylated-ERM is essential for cell adhesion to substrata. Thus, cell adhesion and non-adhesion are regulated by phosphorylation of ERM proteins. We are studying the regulation and functions of adhesion-free cell surface, which we call as “Free Surface Cell Biology”.

Free Surface Cell Biology

Elucidation of molecular mechanism of cell motility(Akira Nagasaki)

Cell migration plays a major role in a variety of biological processes including cancer metastasis and detailed understanding of associated mechanisms will lead to advances in the medical sciences, for example, in drug discovery for cancer therapy. Especially, actin filaments are organized into several cellular structures, and are involved in several cell motilities including cell division, intercellular transport and cell migration, etc. Therefore, we focus on physiological role of actin using microscopic imaging methods. Furthermore, we develop research tools such as new actin probes and high-performance gene editing vectors for our study.

Elucidation of molecular mechanism of cell motility

Single cell measurements and manipulations by using "microcups" (Hyonchol Kim)

We are trying to develop new applications of cup-shaped metal hemispheres, "microcups", for single cell measurements and manipulations. One development is molecular sensing in single cell level. In the technology, target cells were captured in concaves of microcups, and molecular expressions on the cells can be detected with probe molecules immobilized on inner surfaces of the cups. Another is single cell manipulation and force measurement by using atomic force microscopy (AFM). In the technology, a microcup was attached on an apex of AFM cantilever, a target cell was picked up by using the "cup-chip", and intercellular adhesion strengths can be quantitatively measured. These developed technologies are applied to study intercellular interactions in tumor microenvironments.

Single cell measurements and manipulations by using "microcups"

Functional analysis of intermediate filament in the metastasis process of breast cancer cell (Ayana Yamagishi)

Intermediate filament Nestin which is one of the cytoskeletal proteins highly expresses in high metastatic cancer cell. Because recent study reported that knockdown of nestin led the decrease of metastatic ability in cancer cells, nestin is considered to be involved in the cancer cell metastasis. Therefore, we focus on nestin as a novel molecular target for inhibition of cancer metastasis and are analyzing its function by use of nestin knockout mouse breast cancer cell.

Functional analysis of intermediate filament in the metastasis process of breast cancer cell

Development of monitoring technologies of coastal and oceanic ecosystem (Tatsuro Akiba)

Technologies for automatic measurement of abundance of zooplankton and phytoplankton, and a fine scale sampler have been developed for the study of vertical distribution of constituents in water column.

Development of monitoring technologies of coastal and oceanic ecosystem

List of Publications

20172016201520142013201220112010

Staff:

  • Chikashi Nakamura (Research Group Leader)

  • Keiko Hirose

  • Tatsuro Akiba 

  •  Akira Nagasaki

  • Kouichi Tachibana

  • Hyonchol Kim

  • Ayana Yamagishi