Atmospheric resuspension of insoluble radioactive cesium-bearing particles found in the difficult-to-return area in Fukushima

The deposition of insoluble radiocesium-bearing microparticles (CsMPs), which were released from the Fukushima Daiichi Nuclear Power Plant (F1NPP) accident in March 2011, has resulted in the widespread contamination of eastern Japan. Obviously, these deposited insoluble CsMPs may become the secondary contamination sources by atmospheric migration or other environmental transferring process; however, the understanding of the transport mechanism remains non-elucidation, and the relevant evidence has not been directly provided. This study, for the first time, provides the direct evidence for the resuspension of these insoluble CsMPs to the atmosphere from (1) proximity of ¹³⁷Cs radioactivity and resemblance of the morphology and the elemental compositions of CsMPs in the samples of soil and aerosol derived from the same sampling site, (2) the special characteristics of the resuspended CsMPs of which the ratios of Na/Si, K/Si and/or Cs/Si were smaller than those from the initially released CsMPs collected at either long distance or near F1NPP, which can be ascribed to the slowly natural corrosion of CsMPs by the loss of the small amount of soluble contents in CsMPs, and (3) high CsMPs concentration of 10 granules/g in the surface soil of our sampling site and high resuspension frequency of CsMPs in spring when predominant suspended particles were soil dust. Specifically, 15 single CsMPs were successfully isolated from the aerosol filters collected by unmanned high-volume air samplers at a severely polluted area in Fukushima Prefecture, about 25 km away from F1NPP, from January 2015 to September 2019. The mean diameter of these CsMPs was 1.8 ± 0.5 μm, and the average ¹³⁷Cs radioactivity was 0.35 ± 0.23 Bq/granule. The contribution rate of the resuspended CsMPs to the atmospheric radiocesium was estimated from the ratio of ¹³⁷Cs radioactivity of a single CsMP to that of the aerosol filter to be of 23.9 ± 15.3%. There has been no considerable decreasing trend in the annual CsMP resuspension frequency

Co-Overexpression of GEP100 and AMAP1 Proteins Correlates with Rapid Local Recurrence after Breast Conservative Therapy

A major problem of current cancer research and therapy is prediction of tumor recurrence after initial treatment, rather than the simple biological characterization of the malignancy and proliferative properties of tumors. Breast conservation therapy (BCT) is a well-approved, standard treatment for patients with early stages of breast cancer, which consists of lumpectomy and whole-breast irradiation. In spite of extensive studies, only 'age' and 'Ki-67 positivity' have been identified to be well correlated with local recurrence after BCT. An Arf6 pathway, activated by GEP100 under receptor tyrosine kinases (RTKs) and employs AMAP1 as its effector, is crucial for invasion and metastasis of some breast cancer cells. This pathway activates beta 1 integrins and perturbs E-cadherin-based adhesions, hence appears to be integral for epithelial-mesenchymal transdifferentiation (EMT). We here show that expression of the Arf6 pathway components statistically correlates with rapid local recurrence after BCT. We retrospectively analyzed four hundred seventy-nine patients who received BCT in Hokkaido University Hospital, and found 20 patients had local recurrence. We then analyzed pathological samples of patients who experienced local recurrence by use of Kaplan-Meier analysis, Stepwise regression analysis and the t-test, coupled with immunostaining, and found that co-overexpression of GEP100 and AMAP1 correlates with rapidity of the local recurrence. Their margin-status, node-positivity, and estrogen receptor (ER)-or progesterone receptor (PgR)positivity did not correlated with the rapidity. This study is the first to show that expression of a certain set of proteins correlates with the rapidity of local recurrence. Our results are useful not only for prediction, but highlight the possibility of developing novel strategies to block local recurrence. We also discuss why mRNAs encoding these proteins have not been identified to correlate with local recurrence by previous conventional gene expression profiling analyses

TGF-β-Neutralizing Antibody 1D11 Enhances Cytarabine-Induced Apoptosis in AML Cells in the Bone Marrow Microenvironment.

Hypoxia and interactions with bone marrow (BM) stromal cells have emerged as essential components of the leukemic BM microenvironment in promoting leukemia cell survival and chemoresistance. High levels of transforming growth factor beta 1 (TGFβ1) produced by BM stromal cells in the BM niche regulate cell proliferation, survival, and apoptosis, depending on the cellular context. Exogenous TGFβ1 induced accumulation of acute myeloid leukemia (AML) cells in a quiescent G0 state, which was further facilitated by the co-culture with BM-derived mesenchymal stem cells (MSCs). In turn, TGFβ-neutralizing antibody 1D11 abrogated rhTGFβ1 induced cell cycle arrest. Blocking TGFβ with 1D11 further enhanced cytarabine (Ara-C)-induced apoptosis of AML cells in hypoxic and in normoxic conditions. Additional constituents of BM niche, the stroma-secreted chemokine CXCL12 and its receptor CXCR4 play crucial roles in cell migration and stroma/leukemia cell interactions. Treatment with 1D11 combined with CXCR4 antagonist plerixafor and Ara-C decreased leukemia burden and prolonged survival in an in vivo leukemia model. These results indicate that blockade of TGFβ by 1D11 and abrogation of CXCL12/CXCR4 signaling may enhance the efficacy of chemotherapy against AML cells in the hypoxic BM microenvironment

β1-Integrin via NF-κB signaling is essential for acquisition of invasiveness in a model of radiation treated in situ breast cancer.

IntroductionDuctal carcinoma in situ (DCIS) is characterized by non-invasive cancerous cell growth within the breast ducts. Although radiotherapy is commonly used in the treatment of DCIS, the effect and molecular mechanism of ionizing radiation (IR) on DCIS are not well understood, and invasive recurrence following radiotherapy remains a significant clinical problem. This study investigated the effects of IR on a clinically relevant model of Akt-driven DCIS and identified possible molecular mechanisms underlying invasive progression in surviving cells.MethodsWe measured the level of phosphorylated-Akt (p-Akt) in a cohort of human DCIS specimens by immunohistochemistry (IHC) and correlated it with recurrence risk. To model human DCIS, we used Akt overexpressing human mammary epithelial cells (MCF10A-Akt) which, in three-dimensional laminin-rich extracellular matrix (lrECM) and in vivo, form organotypic DCIS-like lesions with lumina expanded by pleiomorphic cells contained within an intact basement membrane. In a population of cells that survived significant IR doses in three-dimensional lrECM, a malignant phenotype emerged creating a model for invasive recurrence.ResultsP-Akt was up-regulated in clinical DCIS specimens and was associated with recurrent disease. MCF10A-Akt cells that formed DCIS-like structures in three-dimensional lrECM showed significant apoptosis after IR, preferentially in the luminal compartment. Strikingly, when cells that survived IR were repropagated in three-dimensional lrECM, a malignant phenotype emerged, characterized by invasive activity, up-regulation of fibronectin, α5β1-integrin, matrix metalloproteinase-9 (MMP-9) and loss of E-cadherin. In addition, IR induced nuclear translocation and binding of nuclear factor-kappa B (NF-κB) to the β1-integrin promoter region, associated with up-regulation of α5β1-integrins. Inhibition of NF-κB or β1-integrin signaling abrogated emergence of the invasive activity.ConclusionsP-Akt is up-regulated in some human DCIS lesions and is possibly associated with recurrence. MCF10A-Akt cells form organotypic DCIS-like lesions in three-dimensional lrECM and in vivo, and are a plausible model for some forms of human DCIS. A population of Akt-driven DCIS-like spheroids that survive IR progresses to an invasive phenotype in three-dimensional lrECM mediated by β1-integrin and NF-κB signaling

β1-Integrin via NF-κB signaling is essential for acquisition of invasiveness in a model of radiation treated in situ breast cancer.

IntroductionDuctal carcinoma in situ (DCIS) is characterized by non-invasive cancerous cell growth within the breast ducts. Although radiotherapy is commonly used in the treatment of DCIS, the effect and molecular mechanism of ionizing radiation (IR) on DCIS are not well understood, and invasive recurrence following radiotherapy remains a significant clinical problem. This study investigated the effects of IR on a clinically relevant model of Akt-driven DCIS and identified possible molecular mechanisms underlying invasive progression in surviving cells.MethodsWe measured the level of phosphorylated-Akt (p-Akt) in a cohort of human DCIS specimens by immunohistochemistry (IHC) and correlated it with recurrence risk. To model human DCIS, we used Akt overexpressing human mammary epithelial cells (MCF10A-Akt) which, in three-dimensional laminin-rich extracellular matrix (lrECM) and in vivo, form organotypic DCIS-like lesions with lumina expanded by pleiomorphic cells contained within an intact basement membrane. In a population of cells that survived significant IR doses in three-dimensional lrECM, a malignant phenotype emerged creating a model for invasive recurrence.ResultsP-Akt was up-regulated in clinical DCIS specimens and was associated with recurrent disease. MCF10A-Akt cells that formed DCIS-like structures in three-dimensional lrECM showed significant apoptosis after IR, preferentially in the luminal compartment. Strikingly, when cells that survived IR were repropagated in three-dimensional lrECM, a malignant phenotype emerged, characterized by invasive activity, up-regulation of fibronectin, α5β1-integrin, matrix metalloproteinase-9 (MMP-9) and loss of E-cadherin. In addition, IR induced nuclear translocation and binding of nuclear factor-kappa B (NF-κB) to the β1-integrin promoter region, associated with up-regulation of α5β1-integrins. Inhibition of NF-κB or β1-integrin signaling abrogated emergence of the invasive activity.ConclusionsP-Akt is up-regulated in some human DCIS lesions and is possibly associated with recurrence. MCF10A-Akt cells form organotypic DCIS-like lesions in three-dimensional lrECM and in vivo, and are a plausible model for some forms of human DCIS. A population of Akt-driven DCIS-like spheroids that survive IR progresses to an invasive phenotype in three-dimensional lrECM mediated by β1-integrin and NF-κB signaling

Simultaneous blockade of TGF-β and CXCL12/CXCR4 signaling may enhance the efficacy of chemotherapy against AML cells in the hypoxic BM microenvironment.

<p>Within the BM microenvironment, TGF-β secreted by stromal cells induces cell cycle arrest of AML cells through p21 upregulation that is inhibited by 1D11. Combination of Plerixafor, which inhibits CXCL12-induced migration, and 1D11, which blocks TGF-β signaling, abrogates stroma-mediated chemoresistance and promotes the antileukemia effects of chemotherapy.</p

1D11 reverses TGF-β-mediated cell cycle inhibition and anti-apoptotic effects.

<p>(A)(B) MV4;11 cells were treated with rhTGF-β1 (2 ng/ml), with and without 1D11 (10 µM) or 13C4 (10 µM), for 72 hours under serum-starved conditions and cultured without and with MSCs, as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062785#s2" target="_blank">Materials and Methods</a>. (A) The percentage of Annexin V–positivity by flow cytometry analysis. Bar graph represent percentages of annexin V–positive cells (mean± SD) from three independent experiments. (B) Flow cytometric cell cycle analysis by PI staining. Bar graphs represent percentages of SubG₁- and G₀/G₁-phase cells (mean± SD) from three independent experiments. Graphs show the means ± SD of the results from three independent experiments. *<i>P</i><0.05, **<i>P</i><0.01. (C) Primary AML cells harboring mutant FLT3-ITD (Pt #1–3) or wt-FLT3 (Pt #4–10) were incubated for 48 h with rhTGF-β1 (2 ng/ml), 1D11 (10 µM), with or without MSCs co-culture condition. Clinical characteristics of patients are summarized in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062785#pone.0062785.s002" target="_blank">Table S1</a>. The percentage of G₀/G₁-, S- and G₂/M-phase cells were detected by flow cytometric PI cell cycle analysis. Average show the means ± SEM of the results from ten (i) or six (ii) primary AML cells, respectively.</p

Combination of 1D11, Plerixafor, and Ara-C induces potent antitumor effects <b><i>in vivo</i></b><b>.</b>

<p>Ba/F3-ITD-luciferase leukemia cells were injected into nude mice as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062785#s2" target="_blank">Materials and Methods</a>. (A) Serial bioluminescence images (i) and luciferase intensity (ii) of mice in the groups receiving 1D11, Ara-C, Plerixafor, one of the combinations indicated, or no treatment (control) were taken on days 13 and 17 after tumor cell injection. *<i>P</i>≤0.05, **<i>P</i><0.01. (B) Histologic sections of bone marrow taken from mice on day 17 were stained with H&E or anti-GFP antibody.</p