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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

Overexpression of Snail in retinal pigment epithelial triggered epithelial–mesenchymal transition

Highlights: • First reported overexpression of Snail in RPE cells could directly trigger EMT. • Further confirmed the regulator role of Snail in RPE cells EMT in vitro. • Snail may be a potential therapeutic target to prevent the fibrosis of PVR. - Abstract: Snail transcription factor has been implicated as an important regulator in epithelial–mesenchymal transition (EMT) during tumourigenesis and fibrogenesis. Our previous work showed that Snail transcription factor was activated in transforming growth factor β1 (TGF-β1) induced EMT in retinal pigment epithelial (RPE) cells and may contribute to the development of retinal fibrotic disease such as proliferative vitreoretinopathy (PVR). However, whether Snail alone has a direct role on retinal pigment epithelial–mesenchymal transition has not been investigated. Here, we analyzed the capacity of Snail to drive EMT in human RPE cells. A vector encoding Snail gene or an empty vector were transfected into human RPE cell lines ARPE-19 respectively. Snail overexpression in ARPE-19 cells resulted in EMT, which was characterized by the expected phenotypic transition from a typical epithelial morphology to mesenchymal spindle-shaped. The expression of epithelial markers E-cadherin and Zona occludin-1 (ZO-1) were down-regulated, whereas mesenchymal markers a-smooth muscle actin (a-SMA) and fibronectin were up-regulated in Snail expression vector transfected cells. In addition, ectopic expression of Snail significantly enhanced ARPE-19 cell motility and migration. The present data suggest that overexpression of Snail in ARPE-19 cells could directly trigger EMT. These results may provide novel insight into understanding the regulator role of Snail in the development of retinal pigment epithelial–mesenchymal transition.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Metformin inhibits epithelial–mesenchymal transition in prostate cancer cells: Involvement of the tumor suppressor miR30a and its target gene SOX4

Highlights: • Metformin inhibits TGF-β-induced EMT in prostate cancer (PCa) cells. • Metformin upregulates tumor suppressor miR30a and downregulates SOX4 in PCa cells. • SOX4 is a target gene of miR30a. - Abstract: Tumor metastasis is the leading cause of mortality and morbidity of prostate cancer (PCa) patients. Epithelial–mesenchymal transition (EMT) plays a critical role in cancer progression and metastasis. Recent evidence suggested that diabetic patients treated with metformin have lower PCa risk and better prognosis. This study was aimed to investigate the effects of metformin on EMT in PCa cells and the possible microRNA (miRNA)-based mechanisms. MiRNAs have been shown to regulate various processes of cancer metastasis. We herein showed that metformin significantly inhibits proliferation of Vcap and PC-3 cells, induces G0/G1 cell cycle arrest and inhibits invasiveness and motility capacity of Vcap cells. Metformin could inhibit TGF-β-induced EMT in Vcap cells, as manifested by inhibition of the increase of N-cadherin (p = 0.013), Vimentin (p = 0.002) and the decrease of E-cadherin (p = 0.0023) and β-catenin (p = 0.034) at mRNA and protein levels. Notably, we demonstrated significant upregulation of miR30a levels by metformin (P < 0.05) and further experiments indicated that miR30a significantly inhibits proliferation and EMT process of Vcap cells. Interestingly, we identified that SOX4, a previously reported oncogenic transcriptional factor and modulator of EMT, is a direct target gene of miR30a. Finally, we screened the expression of miR30a and SOX4 in 84 PCa cases with radical prostatectomy. Of note, SOX4 overexpression is significantly associated with decreased levels of miR30a in PCa cases. In all, our study suggested that inhibition of EMT by metformin in PCa cells may involve upregulation of miR30a and downregulation of SOX4.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Epstein-Barr virus-encoded latent membrane protein 1 induces epithelial to mesenchymal transition by inducing V-set Ig domain containing 4 (VSIG4) expression via NF-kB in renal tubular epithelial HK-2 cells

The epithelial to mesenchymal transition (EMT), a hallmark of chronic kidney disease, is a key event in the conversion from tubular epithelial cells to myofibroblasts in renal fibrosis. Epstein-Barr virus (EBV) is a γ-herpes oncovirus associated with chronic kidney disease. However, the relationship between EBV and the EMT process in renal tubular epithelial cells is not well understood. Among EBV-latent genes, EBV-encoded latent membrane protein 1 (LMP1) induces EMT by regulating a variety of molecules in EBV-induced oncogenic transformation. In this study, we investigated EBV-encoded LMP1 and EMT process markers in human proximal tubule epithelial cell line HK-2. LMP1 overexpression induces cell morphological changes via the epithelial to mesenchymal process in HK-2 cells, and these changes accelerate cell proliferation, cell motility, and invasion. Furthermore, VSIG4 upregulation by EBV-LMP1 induced LMP1-mediated EMT, cell motility, and invasion. VSIG4 upregulation by LMP1 was regulated at the transcriptional level via the NF-kB signaling axis. These results suggest that EBV-encoded LMP1 regulates EMT through the NF-kB-VSIG4 axis in HK-2 cells, and VSIG4 is a potential target in EBV-induced chronic kidney diseases. - Highlights: • Epstein Barr virus-encoded LMP1 overexpression induces epithelial to mesenchymal transition in renal epithelial HK-2 cells. • Upregulation of VISG4 expression by EBV-LMP1 plays an important role in LMP1-induced EMT process in HK-2 cells. • VSIG4 upregulation by EBV-LMP1 is regulated at transcriptional level via LMP1-induced NF-kB activation. • The interruption of VSIG4 expression could be a potential strategy for treatment of EBV-infected renal diseases.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

K-ras mutation promotes ionizing radiation-induced invasion and migration of lung cancer in part via the Cathepsin L/CUX1 pathway

Highlights: • CTSL has important roles in the regulation of invasion and migration in NSCLC and is promoted by mutated K-ras. • Mutated K-ras and IR-induced CTSL play crucial roles in the EMT in the lung cancer. • The regulatory effects of CTSL on the EMT are attributed to proteolytic processing of the transcription factor CUX1. • Inhibition of CTSL or CUX1 may be a promising therapeutic target. • CTSL is a promising therapeutic target to overcome the invasion and migration induced by IR. K-ras mutation is involved in cancer progression including invasion and migration, but the underlying mechanism is not yet clear. Cathepsin L is a lysosomal cysteine protease and has recently been associated with invasion and migration in human cancers when it is overexpressed. Our recent studies have shown that ionizing radiation (IR) enhanced expression of cathepsin L and increased invasion and migration of tumor cells, but the molecular mechanism is still unclear. In the present study, the effects of K-ras mutation and IR induced invasion and migration of lung cancer as well as the underlying mechanisms were investigated both in vitro and in vivo. Firstly, the levels of cathepsin L and epithelial mesenchymal transition (EMT) marker proteins remarkably changed in A549 (K-ras mutant) after irradiation compared with H1299 (K-ras wild), thereby promoting invasion and migration. Additionally, cathepsin L and its downstream transcription factor CUX1/p110 were increased after irradiation in A549 transfected with CUX1/p200, and the proteolytic processing of CUX1 by cathepsin L was remarkably increased after co-transfection of CUX1/p200 and cathepsin L-lentivirus in H1299. In addition, delivery of a mutant K-ras (V12) into HEK 293 cells stimulated EMT after irradiation due to the accumulation of cathepsin L. Moreover, mutated K-ras was associated with IR-induced cathepsin L and EMT in BALB/c nude mice. Finally, the level of cathepsin L expression was higher in samples carrying a K-ras mutation than in wild-type K-ras samples and the mesenchymal markers were upregulated in the samples of mutant K-ras, whereas the epithelial marker E-cadherin was downregulated in non-small cell lung cancers tissues. In conclusion, the findings demonstrated that mutated K-ras promotes cathepsin L expression and plays a pivotal role in EMT of human lung cancer. The regulatory effect of IR-induced cathepsin L on lung cancer invasion and migration was partially attributed to the Cathepsin L /CUX1-mediated EMT signaling pathway. This study will provide cathepsin L as a potential target for tumor therapy.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Silencing PFKP inhibits starvation-induced autophagy, glycolysis, and epithelial mesenchymal transition in oral squamous cell carcinoma

Highlights: • The effect of starvation on glycolysis, autophagy and EMT in OSCC. • We verified the PFKP higher expression under starvation condition. • PFKP modulates starvation mediated glycolysis, autophagy, EMT of OSCC. • PFKP knockdown inhibits OSCC xenograft tumor growth. • The role of PFKP on clinicopathology in the progression of OSCC. The tumor starvation microenvironment plays a pivotal role in the malignant progression of cancer, which is closely related to autophagy, glycolysis, and epithelial mesenchymal transition (EMT). Nevertheless, the underlying mechanisms of the starvation-mediated malignant phenotype are still not well documented. In this study, we aimed to investigate the effect of starvation on glycolysis, autophagy, and EMT in OSCC and to further elucidate the key metabolic modulator. The results showed that starvation can induce autophagy, EMT, and enhanced glycolysis in OSCC cells. We determined that the expression of the key glycolytic enzyme phosphofructokinase-platelet (PFKP) obviously increased under starvation conditions and that PFKP knockdown inhibited starvation-mediated glycolysis, autophagy and EMT in OSCC cells. Moreover, we confirmed that PFKP knockdown inhibited OSCC xenograft growth in vivo. In addition, PFKP expression was significantly increased in OSCC patients and its upregulation was associated with the presence of tumor pathological differentiation and lymph node metastasis. Taken together, our findings demonstrate that PFKP is necessary for starvation-mediated autophagy, glycolysis, and EMT, thereby promoting the malignant progression of OSCC.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Gauge-symmetrization method for energy-momentum tensors in high-order electromagnetic field theories

For electromagnetic field theories, canonical energy-momentum conservation laws can be derived from the underpinning spacetime translation symmetry according to the Noether procedure. However, the canonical energy-momentum tensors (EMTs) are neither symmetric nor gauge-symmetric (gauge invariant). The Belinfante-Rosenfeld (BR) method is a well-known procedure to symmetrize the EMTs, which also renders them gauge symmetric for first-order field theories. High-order electromagnetic field theories appear in the study of gyrokinetic systems for magnetized plasmas and the Podolsky system for the radiation reaction of classical charged particles. For these high-order field theories, gauge-symmetric EMTs are not necessarily symmetric and vice versa. In the present study, we develop a new gauge-symmetrization method for EMTs in high-order electromagnetic field theories. The Noether procedure is carried out using the Faraday tensor $F_{μν}$, instead of the 4-potential $A_{μ}$, to derive a canonical EMT $T^{μν}_{N}$. We show that the gauge-dependent part of $T^{μν}_{N}$ can be removed using the displacement-potential tensor $F^{σμν}$ ≡ $D^{σμ}A^{ν}/4π$, where $D^{σμ}$ is the antisymmetric electric displacement tensor. This method gauge-symmetrizes the EMT without necessarily making it symmetric, which is adequate for applications not involving general relativity. For first-order electromagnetic field theories, such as the standard Maxwell system, $F^{σμν}$ reduces to the familiar BR superpotential $S^{σμν}$, and the method developed can be used as a simpler procedure to calculate $S^{σμν}$ without employing the angular momentum tensor in 4D spacetime. When the electromagnetic system is coupled to classical charged particles, the gauge-symmetrization method for EMTs is shown to be effective as well.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2019

Exergy surface shaping and thermodynamic flow control of electro-mechanical-thermal systems

Our work extends the concepts and tools of Hamiltonian Surface Shaping and Power Flow Control (HS SPFC) for electro-mechanical (EM) systems(i.e., adiabatic irreversible work processes and Hamiltonian natural systems)to Exergy Surface Shaping and Thermodynamic Flow Control (ESSTFC) for electro-mechanical-thermal (EMT) systems (i.e., irreversible work processes with heat and mass flows). The extension of HSSPFC requires the development of exergy potential functions, irreversible entropy production terms of the entropy balance equation to obtain the exergy destruction terms for inclusion in the exergy balance equation, and variational principles for producing consistent equations of motion for coupled EMT systems. The Hamiltonian for natural EM systems is an exergy potential function which leaves the development of exergy potential functions for the thermal part of the coupled models. This development is completed by integrating the exergy function over the control volume subject to the modeling assumptions. The irreversible entropy production terms are the exergy destruction terms of the exergy balance equation and the generalization of the mechanical dissipation and electrical resistance within EM systems. These generalized dissipation terms enable the derivation of a consistent set of coupled equations of motion for EMT systems. For this paper, Extended Irreversible Thermodynamics will be utilized to produce consistent thermal equations of motion that directly include the exergy destruction terms. There are several variational principles that are available for application to EMT systems. We focus on the variational principles developed by Biot and Fung [1, 2]. Furthermore, a simplified EMT system that models the EMT dynamics of a Navy ship equipped with a railgun is used to demonstrate the application of ESSTFC for designing high performance, stable nonlinear controllers for EMT systems.

42 ENGINEERING↗
DOE OSTI2015

1,25(OH)2D3 attenuates TGF-β1/β2-induced increased migration and invasion via inhibiting epithelial–mesenchymal transition in colon cancer cells

1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) has been reported to inhibit proliferation and migration of multiple types of cancer cells. However, the mechanism underlying its anti-metastasis effect is not fully illustrated. In this study, the effect of 1,25(OH)2D3 on TGF-β1/β2-induced epithelial–mesenchymal transition (EMT) is tested in colon cancer cells. The results suggest that 1,25(OH)2D3 inhibited TGF-β1/β2-induced increased invasion and migration of in SW-480 and HT-29 cells. 1,25(OH)2D3 also inhibited the cadherin switch in SW-480 and HT-29 cells. TGF-β1/β2-induced increased expression of EMT-related transcription factors was also inhibited by 1,25(OH)2D3. 1,25(OH)2D3 also inhibited the secretion of MMP-2 and MMP-9 and increased expression of F-actin induced by TGF-β1/β2 in SW-480 cells. Taken together, this study suggests that the suppression of EMT might be one of the mechanisms underlying the anti-metastasis effect of 1,25(OH)2D3 in colon cancer cells. - Highlights: • TGF-β1/β2-induced model of EMT was used in this study to test the effect of 1,25(OH)2D3 on EMT in colon cancer cells. • 1,25(OH)2D3 inhibited TGF-β1/β2-induced increased migration and invasion. • 1,25(OH)2D3 inhibited TGF-β1/β2-induced increased level of EMT-related transcription factors. • 1,25(OH)2D3 inhibited TGF-β1/β2-induced increased expression of F-actin in SW-480 cells.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Mechanism of c-Met and EGFR tyrosine kinase inhibitor resistance through epithelial mesenchymal transition in non-small cell lung cancer

According to currently available estimates from Cancer Research UK, 14.1 million new lung cancer cases were diagnosed and a staggering 8.2 million people worldwide died from lung cancer in 2012. EGFR and c-Met are two tyrosine kinase receptors most commonly overexpressed or mutated in Non-small Cell Lung Cancer (NSCLC) resulting in increased proliferation and survival of lung cancer cells. Tyrosine kinase inhibitors (TKIs), such as erlotinib, approved by the FDA as first/second line therapy for NSCLC patients have limited clinical efficacy due to acquired resistance. In this manuscript, we investigate and discuss the role of epithelial mesenchymal transition (EMT) in the development of resistance against EGFR and c-Met TKIs in NSCLC. Our findings show that Zeb-1, a transcriptional repressor of E-Cadherin, is upregulated in TKI-resistant cells causing EMT. We observed that TKI-resistant cells have increased gene and protein expression of EMT related proteins such as Vimentin, N-Cadherin, β-Catenin and Zeb-1, while expression of E-Cadherin, an important cell adhesion molecule, was suppressed. We also confirmed that TKI-resistant cells display mesenchymal cell type morphology, and have upregulation of β-Catenin which may regulate expression of Zeb-1, a transcriptional repressor of E-Cadherin in TKI-resistant NSCLC cells. Finally, we show that down-regulating Zeb-1 by inducing miR-200a or β-Catenin siRNA can increase drug sensitivity of TKI-resistant cells. - Highlights: • Resistance to TKIs in NSCLC cells is mediated via modulation in EMT related proteins. • EMT may induce c-Met mediated TKI resistance, similar to EGFR TKI resistance. • Role of β-catenin and cadherins in TKI resistance was validated by FACS and qPCR. • Knockdown of β-catenin or Zeb-1 can increase TKI sensitivity in TKI-resistant cells. • Targeting key EMT related proteins may overcome TKI resistance in NSCLC.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Quercetin restrains TGF-β1-induced epithelial–mesenchymal transition by inhibiting Twist1 and regulating E-cadherin expression

Emerging evidence has indicated that transforming growth factor-beta 1 (TGF-β1) induces the epithelial–mesenchymal transition (EMT) in cancer cells, thus promoting their motility and invasiveness. Quercetin, a member of the polyphenolic flavonoid family, has been reported to display anticancer activity against a broad range of cancer cell types. Indeed, numerous studies have shown the cancer preventive effects and molecular mechanisms of quercetin in vitro using diverse cell model systems. However, the potential effect of quercetin on EMT remains unclear. In this study, we identified a unique function of quercetin in inhibiting the EMT process induced by TGF-β1. In particular, quercetin rescued the morphological changes and EMT-like phenotypes in TGF-β1-activated SW480 cells, and this inhibition of TGF-β1-induced EMT was mediated via the suppression of Twist1 expression. In addition, quercetin strongly suppressed TGF-β1-induced invasion of SW480 cells. Thus, quercetin may be considered a novel therapeutic agent for the treatment of patients with refractory cancer and for the prevention of the metastatic cascade initiated by EMT.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

Knockdown of dual specificity phosphatase 4 enhances the chemosensitivity of MCF-7 and MCF-7/ADR breast cancer cells to doxorubicin

Background: Breast cancer is the major cause of cancer-related deaths in females world-wide. Doxorubicin-based therapy has limited efficacy in breast cancer due to drug resistance, which has been shown to be associated with the epithelial-to-mesenchymal transition (EMT). However, the molecular mechanisms linking the EMT and drug resistance in breast cancer cells remain unclear. Dual specificity phosphatase 4 (DUSP4), a member of the dual specificity phosphatase family, is associated with cellular proliferation and differentiation; however, its role in breast cancer progression is controversial. Methods: We used cell viability assays, Western blotting and immunofluorescent staining, combined with siRNA interference, to evaluate chemoresistance and the EMT in MCF-7 and adriamycin-resistant MCF-7/ADR breast cancer cells, and investigate the underlying mechanisms. Results: Knockdown of DUSP4 significantly increased the chemosensitivity of MCF-7 and MCF-7/ADR breast cancer cells to doxorubicin, and MCF-7/ADR cells which expressed high levels of DUSP4 had a mesenchymal phenotype. Furthermore, knockdown of DUSP4 reversed the EMT in MCF-7/ADR cells, as demonstrated by upregulation of epithelial biomarkers and downregulation of mesenchymal biomarkers, and also increased the chemosensitivity of MCF-7/ADR cells to doxorubicin. Conclusions: DUSP4 might represent a potential drug target for inhibiting drug resistance and regulating the process of the EMT during the treatment of breast cancer. - Highlights: • We used different technologies to prove our conclusion. • DUSP4 knockdown increased doxorubicin chemosensitivity in breast cancer cells. • DUSP4 is a potential target for combating drug resistance in breast cancer. • DUSP4 is a potential target for regulating the EMT in breast cancer.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Co-culture of 3D tumor spheroids with fibroblasts as a model for epithelial–mesenchymal transition in vitro

Epithelial–mesenchymal transition (EMT) acts as a facilitator of metastatic dissemination in the invasive margin of malignant tumors where active tumor–stromal crosstalks take place. Co-cultures of cancer cells with cancer-associated fibroblasts (CAFs) are often used as in vitro models of EMT. We established a tumor–fibroblast proximity co-culture using HT-29 tumor spheroids (TSs) with CCD-18co fibroblasts. When co-cultured with TSs, CCD-18co appeared activated, and proliferative activity as well as cell migration increased. Expression of fibronectin increased whereas laminin and type I collagen decreased in TSs co-cultured with fibroblasts compared to TSs alone, closely resembling the margin of in vivo xenograft tissue. Active TGFβ1 in culture media significantly increased in TS co-cultures but not in 2D co-cultures of cancer cells–fibroblasts, indicating that 3D context-associated factors from TSs may be crucial to crosstalks between cancer cells and fibroblasts. We also observed in TSs co-cultured with fibroblasts increased expression of α-SMA, EGFR and CTGF; reduced expression of membranous β-catenin and E-cadherin, together suggesting an EMT-like changes similar to a marginal region of xenograft tissue in vivo. Overall, our in vitro TS–fibroblast proximity co-culture mimics the EMT-state of the invasive margin of in vivo tumors in early metastasis. - Highlights: • An adjacent co-culture of tumor spheroids and fibroblasts is presented as EMT model. • Activation of fibroblasts and increased cell migration were shown in co-culture. • Expression of EMT-related factors in co-culture was similar to that in tumor tissue. • Crosstalk between spheroids and fibroblasts was demonstrated by secretome analysis.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

CCR7 preservation via histone deacetylase inhibition promotes epithelial-mesenchymal transition of hepatocellular carcinoma cells

Highlights: • CCR7 promotes the progression of HCC and is associated with poor survival. • HDAC inhibition induces EMT in HCC cells via up-regulating CCR7. • HDAC inhibition up-regulates CCR7 via reversing the promoter hypoacetylation and increasing CCR7 transcription. The effects of Histone deacetylase (HDAC) inhibition on epithelial-mesenchymal transition (EMT) differs in various types of cancers. However, its function in hepatocellular carcinoma (HCC) is not well-explored. In this study, we investigated the effect of HDAC inhibition on EMT in HCC cells by using trichostatin A (TSA) and valproic acid (VPA). The results showed that TSA/VPA significantly induced EMT phenotype, as demonstrated by the decreased level of E-cadherin, increased level of N-cadherin, vimentin, Twist and snail, and enhanced capacity of cell migration and invasion. In addition, CCR7 was speculated and confirmed as a function target of HDAC inhibition. CCR7 promotes the progression of HCC and is associated with poor survival. Knockdown of CCR7 significantly attenuated the effect of TSA on EMT. Moreover, our results demonstrated that HDAC inhibition up-regulates CCR7 via reversing the promoter hypoacetylation and increasing CCR7 transcription. Taken together, our study has identified the function of HDAC in EMT of HCC and suggested a novel mechanism through which TSA/VPA exerts its carcinogenic roles in HCC. HDAC inhibitors require careful caution before their application as new anticancer drugs.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Novel antibody reagents for characterization of drug- and tumor microenvironment-induced changes in epithelial-mesenchymal transition and cancer stem cells

The presence of cancer stem cells (CSCs) and the induction of epithelial-to-mesenchymal transition (EMT) in tumors are associated with tumor aggressiveness, metastasis, drug resistance, and poor prognosis, necessitating the development of reagents for unambiguous detection of CSC- and EMT-associated proteins in tumor specimens. To this end, we generated novel antibodies to EMT- and CSC-associated proteins, including Goosecoid, Sox9, Slug, Snail, and CD133. Importantly, unlike several widely used antibodies to CD133, the anti-CD133 antibodies we generated recognize epitopes distal to known glycosylation sites, enabling analyses that are not confounded by differences in CD133 glycosylation. For all target proteins, we selected antibodies that yielded the expected target protein molecular weights by Western analysis and the correct subcellular localization patterns by immunofluorescence microscopy assay (IFA); binding selectivity was verified by immunoprecipitation-mass spectrometry and by immunohistochemistry and IFA peptide blocking experiments. Finally, we applied these reagents to assess modulation of the respective markers of EMT and CSCs in xenograft tumor models by IFA. We observed that the constitutive presence of human hepatocyte growth factor (hHGF) in the tumor microenvironment of H596 non-small cell lung cancer tumors implanted in homozygous hHGF knock-in transgenic mice induced a more mesenchymal-like tumor state (relative to the epithelial-like state when implanted in control SCID mice), as evidenced by the elevated expression of EMT-associated transcription factors detected by our novel antibodies. Similarly, our new anti-CD133 antibody enabled detection and quantitation of drug-induced reductions in CD133-positive tumor cells following treatment of SUM149PT triple-negative breast cancer xenograft models with the CSC/focal adhesion kinase (FAK) inhibitor VS-6063. Thus, our novel antibodies to CSC- and EMT-associated factors exhibit sufficient sensitivity and selectivity for immunofluorescence microscopy studies of these processes in preclinical xenograft tumor specimens and the potential for application with clinical samples.

Science & Technology - Other Topics↗
DOE OSTI2014

The network of epithelial–mesenchymal transition: potential new targets for tumor resistance

In multiple cell metazoans, the ability of polarized epithelial cells to convert to motile mesenchymal cells in order to relocate to another location is governed by a unique process termed epithelial-mesenchymal transition (EMT). While being an essential process of cellular plasticity for normal tissue and organ developments, EMT is found to be involved in an array of malignant phenotypes of tumor cells including proliferation and invasion, angiogenesis, stemness of cancer cells and resistance to chemo-radiotherapy. Although EMT is being extensively studied and demonstrated to play a key role in tumor metastasis and in sustaining tumor hallmarks, there is a lack of clear picture of the overall EMT signaling network, wavering the potential clinical trials targeting EMT.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2014

Mechanism-based inhibition of cancer metastasis with (−)-epigallocatechin gallate

Highlights: •EGCG reduced cell motility of highly metastatic human lung cancer cells. •EGCG increased cell stiffness of the cells, indicating the inhibition of phenotypes of EMT. •EGCG inhibited expression of vimentin and Slug in the cells at the leading edge of scratch. •Treatment of MβCD increased cell stiffness, and inhibited cell motility and vimentin expression. •Inhibition of EMT phenotypes with EGCG is a mechanism-based inhibition of cancer metastasis. -- Abstract: Cell motility and cell stiffness are closely related to metastatic activity of cancer cells. (−)-Epigallocatechin gallate (EGCG) has been shown to inhibit spontaneous metastasis of melanoma cell line into the lungs of mice, so we studied the effects of EGCG on cell motility, cell stiffness, and expression of vimentin and Slug, which are molecular phenotypes of epithelial–mesenchymal transition (EMT). Treatments of human non-small cell lung cancer cell lines H1299 and Lu99 with 50 and 100 μM EGCG reduced cell motility to 67.5% and 43.7% in H1299, and 71.7% and 31.5% in Lu99, respectively in in vitro wound healing assay. Studies on cell stiffness using atomic force microscope (AFM) revealed that treatment with 50 μM EGCG increased Young’s modulus of H1299 from 1.24 to 2.25 kPa and that of Lu99 from 1.29 to 2.28 kPa, showing a 2-fold increase in cell stiffness, i.e. rigid elasticity of cell membrane. Furthermore, treatment with 50 μM EGCG inhibited high expression of vimentin and Slug in the cells at a leading edge of scratch. Methyl-β-cyclodextrin, a reagent to deplete cholesterol in plasma membrane, showed inhibition of EMT phenotypes similar that by EGCG, suggesting that EGCG induces inhibition of EMT phenotypes by alteration of membrane organization.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

APBB1 reinforces cancer stem cell and epithelial-to-mesenchymal transition by regulating the IGF1R signaling pathway in non-small-cell lung cancer cells

Amyloid β precursor protein binding family B member 1(APBB1) was first identified as a binding partner of amyloid precursor protein during brain development, but its function in the context of cancer remain unclear. Here we show for the first time that APBB1 is partly associated with intensifying cancer stem cell(CSC) and epithelial-to-mesenchymal transition (EMT) and enhancing radiation-resistant properties of lung cancer cells. We found that APBB1 was highly expressed in ALDH1{sup high} CSC-like cells sorted from A549 lung cancer cells. In APBB1-deficient H460 cells with forced overexpression of APBB1, the protein directly interacted with IGF1Rβ, enhanced phosphorylation of IGF1Rβ/PI3K/AKT pathway(activation) and subsequently induced the phosphorylation of GSK3β(inactivation). This phosphorylation stabilized Snail1, a negative regulator of E-cadherin expression, and regulated β-catenin–mediated ALDH1 expression, which are representative markers for EMT and CSCs, respectively. In contrast, suppression of APBB1 expression with siRNA yielded the opposite effects in APBB1-rich A549 cells. We concluded that APBB1 partly regulates the expression of ALDH1. We also found that APBB1 regulates activation of nuclear factor-κB, which is involved in reducing various stresses including oxidative stress, which suggests that APBB1 is associated with γ-radiation sensitivity. Our findings imply that APBB1 plays an important role in the maintenance of EMT-associated CSC-like properties and γ-radiation resistance via activation of IGF1Rβ/AKT/GSK3β pathway in lung cancer cells, highlighting APBB1 as a potential target for therapeutic cancer treatment. - Highlights: • APBB1 was highly expressed in ALDH1{sup high} cells sorted from A549 cells. • APBB1 is associated with intensifying CSC and EMT and enhancing radiation-resistant properties of lung cancer cells. • APBB1 regulates EMT-associated CSC-like properties and γ-radiation resistance via activation of IGF1Rβ/AKT/GSK3β pathway. • APBB1 partly regulates the expression of ALDH1 via AKT/GSK3β-associated β-catenin pathway.

60 APPLIED LIFE SCIENCES↗