186 research outputs found
Escaping from, moving towards, following a path, squeezing through: lots of opportunities for moving cells
Oxidative Stress, Tumor Microenvironment, and Metabolic Reprogramming: A Diabolic Liaison
Conversely to normal cells, where deregulated oxidative stress drives the activation of death pathways, malignant cells exploit oxidative milieu for its advantage. Cancer cells are located in a very complex microenvironment together with stromal components that participate to enhance oxidative stress to promote tumor progression. Indeed, convincing experimental and clinical evidence underline the key role of oxidative stress in several tumor aspects thus affecting several characteristics of cancer cells. Oxidants influence the DNA mutational potential, intracellular signaling pathways controlling cell proliferation and survival and cell motility and invasiveness as well as control the reactivity of stromal components that is fundamental for cancer development and dissemination, inflammation, tissue repair, and de novo angiogenesis. This paper is focused on the role of oxidant species in the acquisition of two mandatory features for aggressive neoplastic cells, recently defined by Hanahan and Weinberg as new “hallmarks of cancer”: tumor microenvironment and metabolic reprogramming of cancer cells
Redox Regulation of Nonmuscle Myosin Heavy Chain during Integrin Engagement
On the basis of our findings reporting that cell adhesion induces the generation of reactive oxygen species (ROS) after integrin engagement, we were interested in identifying redox-regulated proteins during this process. Mass spectrometry analysis led us to identify nonmuscle myosin heavy chain (nmMHC) as a target of ROS. Our results show that, while nmMHC is reduced in detached/rounded cells, it turns towards an oxidized state in adherent/spread cells due to the integrin-engaged ROS machinery. The functional role of nmMHC redox regulation is suggested by the redox sensitivity of its association with actin, suggesting a role of nmMHC oxidation in cytoskeleton movement. Analysis of muscle MHC (mMHC) redox state during muscle differentiation, a process linked to a great and stable decrease of ROS content, shows that the protein does not undergo a redox control. Hence, we propose that the redox regulation of MHC in nonprofessional muscle cells is mandatory for actin binding during dynamic cytoskeleton rearrangement, but it is dispensable for static and highly organized cytoskeletal contractile architecture in differentiating myotubes
Cancer associated fibroblasts exploit reactive oxygen species through a proinflammatory signature leading to epithelial mesenchymal transition and stemness.
Time-dependent stabilization of hypoxia inducible factor-1α by different intracellular sources of reactive oxygen species.
Electrodynamic friction of a charged particle passing a conducting plate
The classical electromagnetic friction of a charged particle moving with
prescribed constant velocity parallel to a planar imperfectly conducting
surface is reinvestigated. As a concrete example, the Drude model is used to
describe the conductor. The transverse electric and transverse magnetic
contributions have very different character both in the low velocity
(nonrelativistic) and high velocity (ultrarelativistic) regimes. Both numerical
and analytical results are given. Most remarkably, the transverse magnetic
contribution to the friction has a maximum for , and persists
in the limit of vanishing resistivity for sufficiently high velocities. We also
show how Vavilov-\v{C}erenkov radiation can be treated in the same formalism.Comment: 13 pages, 7 figures. This is the extensively revised version accepted
by Physical Review Researc
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