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At least 379 records · Page 21

Near-field radiative heat transfer between rough surfaces modeled using effective media with gradient distribution of dielectric function

Near-field radiative heat transfer (NFRHT) between rough surfaces, due to its widespread presence in engineering practice of near-field energy utilization, requires indepth studies, especially from the perspective of physical mechanism. In this paper, an effective multilayer model is built to approach the NFRHT between random rough surfaces of silicon carbide (SiC). Using the effective medium theory (EMT), the effective dielectric function of each layer is obtained, which forms a gradient distribution of dielectric function along the depth of the medium. The influence of the effective dielectric function on surface phonon polaritons (SPhPs) is analyzed, showing that the effective layers with small filling fraction of SiC feature lower SPhP resonance frequencies than SiC bulk. The coupling of SPhPs from the gradient distribution of dielectric function produces new surface modes that dominates the NFRHT. Investigation on the effect of root mean square height (RMS height, σ) reveals that the peaks of local density of states (LDOS) and spectral heat flux are red-shifted as σ increases, while the spectral heat flux below the peak frequency gets larger. This can be attributed to the coupling of SPhPs inside the rough layer. We also found the total net heat flux between rough surfaces separated by an average distance exceeds that between smooth plates and increases with increasing σ, which offer a new way to enhance NFRHT. Finally, this work provides a reference for the simulation and understanding of the NFRHT between rough surfaces.

42 ENGINEERING↗

Osthole inhibits the invasive ability of human lung adenocarcinoma cells via suppression of NF-κB-mediated matrix metalloproteinase-9 expression

The induction of matrix metalloproteinase (MMP)-9 is particularly important for the invasiveness of various cancer cells. Osthole, a natural coumarin derivative extracted from traditional Chinese medicines, is known to inhibit the proliferation of a variety of tumor cells, but the effect of osthole on the invasiveness of tumor cells is largely unknown. This study determines whether and by what mechanism osthole inhibits invasion in CL1-5 human lung adenocarcinoma cells. Herein, we found that osthole effectively inhibited the migratory and invasive abilities of CL1-5 cells. A zymographic assay showed that osthole inhibited the proteolytic activity of MMP-9 in CL1-5 cells. Inhibition of migration, invasion, and MMP2 and/or MMP-9 proteolytic activities was also observed in other lung adenocarcinoma cell lines (H1299 and A549). We further found that osthole inhibited MMP-9 expression at the messenger RNA and protein levels. Moreover, a chromatin immunoprecipitation assay showed that osthole inhibited the transcriptional activity of MMP-9 by suppressing the DNA binding activity of nuclear factor (NF)-κB in the MMP-9 promoter. Using reporter assays with point-mutated promoter constructs further confirmed that the inhibitory effect of osthole requires an NF-κB binding site on the MMP-9 promoter. Western blot and immunofluorescence assays demonstrated that osthole inhibited NF-κB activity by inhibiting IκB-α degradation and NF-κB p65 nuclear translocation. In conclusion, we demonstrated that osthole inhibits NF-κB-mediated MMP-9 expression, resulting in suppression of lung cancer cell invasion and migration, and osthole might be a potential agent for preventing the invasion and metastasis of lung cancer. -- Highlights: ► Osthole treatment inhibits lung adenocarcinoma cells migration and invasion. ► Osthole reduces the expression and proteolytic activity of MMP-9. ► Osthole inhibits MMP-9 transcription via suppression of NF-κB binding activity. ► Osthole inhibits IκBα degradation and NF-κB nucleus translocation. ► Osthole suppresses EMT by repressing vimentin and inducing E-cadherin expression.

60 APPLIED LIFE SCIENCES↗

Obaculactone protects against bleomycin-induced pulmonary fibrosis in mice

Idiopathic pulmonary fibrosis is a progressive, degenerative and almost irreversible disease. There is hardly an effective cure for lung damage due to pulmonary fibrosis. The purpose of this study was to evaluate the role of obaculactone in an already-assessed model of idiopathic pulmonary fibrosis induced by bleomycin administration. Mice were subjected to intratracheal instillation of bleomycin, and obaculactone was given orally after bleomycin instillation daily for 23 days. Treatment with obaculactone ameliorated body weight loss, lung histopathology abnormalities and pulmonary collagen deposition, with a decrease of the inflammatory cell number and the cytokine level in bronchoalveolar lavage fluid. Moreover, obaculactone inhibited the expression of icam1, vcam1, inos and cox2, and attenuated oxidative stress in bleomycin-treated lungs. Importantly, the production of collagen I and α-SMA in lung tissues as well as the levels of TGF-β1, ALK5, p-Smad2 and p-Smad3 in lung homogenates was also reduced after obaculactone treatment. Finally, the TGF-β1-induced epithelial-mesenchymal transition via Smad-dependent and Smad-independent pathways was reversed by obaculactone. Collectively, these data suggest that obaculactone may be a promising drug candidate for the treatment of idiopathic pulmonary fibrosis. - Highlights: • Obaculactone ameliorates bleomycin-induced pulmonary fibrosis in mice. • Obaculactone mitigates bleomycin-induced inflammatory response in lungs. • Obaculactone exerts inhibitory effects on TGF-β1 signaling and TGF-β1-induced EMT progress.

60 APPLIED LIFE SCIENCES↗

Transient and permanent changes in DNA methylation patterns in inorganic arsenic-mediated epithelial-to-mesenchymal transition

Chronic low dose inorganic arsenic exposure causes cells to take on an epithelial-to-mesenchymal phenotype, which is a crucial process in carcinogenesis. Inorganic arsenic is not a mutagen and thus epigenetic alterations have been implicated in this process. Indeed, during the epithelial-to-mesenchymal transition, morphologic changes to cells correlate with changes in chromatin structure and gene expression, ultimately driving this process. However, studies on the effects of inorganic arsenic exposure/withdrawal on the epithelial-to-mesenchymal transition and the impact of epigenetic alterations in this process are limited. In this study we used high-resolution microarray analysis to measure the changes in DNA methylation in cells undergoing inorganic arsenic-induced epithelial-to-mesenchymal transition, and on the reversal of this process, after removal of the inorganic arsenic exposure. We found that cells exposed to chronic, low-dose inorganic arsenic exposure showed 30,530 sites were differentially methylated, and with inorganic arsenic withdrawal several differential methylated sites were reversed, albeit not completely. Furthermore, these changes in DNA methylation mainly correlated with changes in gene expression at most sites tested but not at all. This study suggests that DNA methylation changes on gene expression are not clear-cut and provide a platform to begin to uncover the relationship between DNA methylation and gene expression, specifically within the context of inorganic arsenic treatment. - Highlights: • Transient and permanent methylation patterns are modulated by iAs exposure. • Arsenite contributes to the epithelial-to-mesenchymal transition. • Arsenite mediated epigenetic changes play a role in EMT.

60 APPLIED LIFE SCIENCES↗

Tumor-produced, active Interleukin-1 {beta} regulates gene expression in carcinoma-associated fibroblasts

Recently we described a co-culture model of periodontal ligament (PDL) fibroblasts and SCC-25 lingual squamous carcinoma cells, which resulted in conversion of normal fibroblasts into carcinoma-associated fibroblasts (CAFs), and in epithelial-mesenchymal transition (EMT) of SCC-25 cells. We have found a constitutive high interleukin-1{beta} (IL1-{beta}) expression in SCC-25 cells in normal and in co-cultured conditions. In our hypothesis a constitutive IL1-{beta} expression in SCC-25 regulates gene expression in fibroblasts during co-culture. Co-cultures were performed between PDL fibroblasts and SCC-25 cells with and without dexamethasone (DEX) treatment; IL1-{beta} processing was investigated in SCC-25 cells, tumor cells and PDL fibroblasts were treated with IL1-{beta}. IL1-{beta} signaling was investigated by western blot and immunocytochemistry. IL1-{beta}-regulated genes were analyzed by real-time qPCR. SCC-25 cells produced 16 kD active IL1-{beta}, its receptor was upregulated in PDL fibroblasts during co-culture, which induced phosphorylation of interleukin-1 receptor-associated kinase-1 (IRAK-1), and nuclear translocalization of NF{kappa}B{alpha}. Several genes, including interferon regulatory factor 1 (IRF1) interleukin-6 (IL-6) and prostaglandin-endoperoxide synthase 2 (COX-2) were induced in CAFs during co-culture. The most enhanced induction was found for IL-6 and COX-2. Treatment of PDL fibroblasts with IL1-{beta} reproduced a time- and dose-dependent upregulation of IL1-receptor, IL-6 and COX-2. A further proof was achieved by DEX inhibition for IL1-{beta}-stimulated IL-6 and COX-2 gene expression. Constitutive expression of IL1-{beta} in the tumor cells leads to IL1-{beta}-stimulated gene expression changes in tumor-associated fibroblasts, which are involved in tumor progression. -- Graphical abstract: SCC-25 cells produce active, processed IL1-{beta}. PDL fibroblasts possess receptor for IL1-{beta}, and its expression is increased 4.56-times in the presence of SCC-25 tumor cells. IL1-{beta} receptor expression in fibroblasts, especially in CAFs represents a major option in coordination of fibroblast and tumor behavior. A key event in IL1-{beta} signaling, the phosphorylation of IRAK1, occurred in co-cultured fibroblasts, which has lead to nuclear translocation of NF{kappa}B{alpha}, and finally to induction of several genes, including BDNF, IRF1, IL-6 and COX-2. The most enhanced induction was found for IL-6 and COX-2.

60 APPLIED LIFE SCIENCES↗

Inherent phenotypic plasticity facilitates progression of head and neck cancer: Endotheliod characteristics enable angiogenesis and invasion

The presence of the EMT (epithelial-mesenchymal transition), EndMT (endothelial-mesenchymal transition) and VM (vasculogenic mimicry) demonstrates the multidirectional extent of phenotypic plasticity in cancers. Previous findings demonstrating the crosstalk between head and neck squamous cell carcinoma (HNSCC) and vascular endothelial growth factor (VEGF) imply that HNSCC cells share some functional commonalities with endothelial cells. Our current results reveal that cultured HNSCC cells not only possess endothelial-specific markers, but also display endotheliod functional features including low density lipoprotein uptake, formation of tube-like structures on Matrigel and growth state responsiveness to VEGF and endostatin. HNSCC cell subpopulations are also highly responsive to transforming growth factor-β1 and express its auxiliary receptor, endoglin. Furthermore, the endotheliod characteristics observed in vitro recapitulate phenotypic features observed in human HNSCC tumors. Conversely, cultured normal human oral keratinocytes and intact or ulcerated human oral epithelia do not express comparable endotheliod characteristics, which imply that assumption of endotheliod features is restricted to transformed keratinocytes. In addition, this phenotypic state reciprocity facilitates HNSCC progression by increasing production of factors that are concurrently pro-proliferative and pro-angiogenic, conserving cell energy stores by LDL internalization and enhancing cell mobility. Finally, recognition of this endotheliod phenotypic transition provides a solid rationale to evaluate the antitumorigenic potential of therapeutic agents formerly regarded as exclusively angiostatic in scope. - Highlights: ► HNSCC tumor cells express endothelial specific markers VE-cadherin, CD31 and vimentin. ► Similarly, cultured HNSCC cells retain expression of these markers. ► HNSCC cells demonstrate functional endotheliod characteristics i.e. AcLDL uptake. ► HNSCC cell subpopulations are highly responsive to TGF- β1, VEGF and endostatin. ► TGF-β1 facilitates cadherin switching and augments invasiveness of HNSCC subpopulations.

60 APPLIED LIFE SCIENCES↗

BCL-2 family protein, BAD is down-regulated in breast cancer and inhibits cell invasion

We have previously demonstrated that the anti-apoptotic protein BAD is expressed in normal human breast tissue and shown that BAD inhibits expression of cyclin D1 to delay cell-cycle progression in breast cancer cells. Herein, expression of proteins in breast tissues was studied by immunohistochemistry and results were analyzed statistically to obtain semi-quantitative data. Biochemical and functional changes in BAD-overexpressing MCF7 breast cancer cells were evaluated using PCR, reporter assays, western blotting, ELISA and extracellular matrix invasion assays. Compared to normal tissues, Grade II breast cancers expressed low total/phosphorylated forms of BAD in both cytoplasmic and nuclear compartments. BAD overexpression decreased the expression of β-catenin, Sp1, and phosphorylation of STATs. BAD inhibited Ras/MEK/ERK and JNK signaling pathways, without affecting the p38 signaling pathway. Expression of the metastasis-related proteins, MMP10, VEGF, SNAIL, CXCR4, E-cadherin and TlMP2 was regulated by BAD with concomitant inhibition of extracellular matrix invasion. Inhibition of BAD by siRNA increased invasion and Akt/p-Akt levels. Clinical data and the results herein suggest that in addition to the effect on apoptosis, BAD conveys anti-metastatic effects and is a valuable prognostic marker in breast cancer. - Highlights: • BAD and p-BAD expressions are decreased in breast cancer compared with normal breast tissue. • BAD impedes breast cancer invasion and migration. • BAD inhibits the EMT and transcription factors that promote cancer cell migration. • Invasion and migration functions of BAD are distinct from the BAD's role in apoptosis.

60 APPLIED LIFE SCIENCES↗

Hispidulin inhibits proliferation and enhances chemosensitivity of gallbladder cancer cells by targeting HIF-1α

Gallbladder cancer (GBC) is an aggressive malignancy of the bile duct, which is associated with a low (5-year) survival and poor prognosis. The transcription factor HIF-1α is implicated in the angiogenesis, cell survival, epithelial mesenchymal transition (EMT) and invasiveness of GBC. In this study, we have investigated the role of HIF-1α in the pathobilogy of GBC and effect of hispidulin on the molecular events controlled by this transcription factor. We observed that hispidulin caused induction of apoptosis, blockade of growth and cell cycle progression in GBC cells. Our results have demonstrated for the first time that hispidulin-exerted anti-tumor effect involved the suppression of HIF-1α signaling. Hispidulin was found to repress the expression of HIF-1α protein dose-dependently without affecting the HIF-1α mRNA expression. In addition, the inhibition of HIF-1α protein synthesis was revealed to be mediated through the activation of AMPK signaling. Hispidulin also sensitized the tumor cells to Gemcitabine and 5-Fluoroucil by down-regulating HIF-1α/P-gp signaling. Given the low cost and exceedingly safe profile, hispidulin appears to be a promising and novel chemosensitizer for GBC treatment. - Highlights: • Hispidulin inhibits proliferation of gallbladder cancer cells by targeting HIF-1α. • Hispidulin regulates HIF-1α via activating AMPK signaling. • Hispidulin sensitized the GBC cells to chemotherapeutics by down-regulating P-gp.

60 APPLIED LIFE SCIENCES↗

Stabilization of gene expression and cell morphology after explant recycling during fin explant culture in goldfish

The development of fin primary cell cultures for in vitro cellular and physiological studies is hampered by slow cell outgrowth, low proliferation rate, poor viability, and sparse cell characterization. Here, we investigated whether the recycling of fresh explants after a first conventional culture could improve physiological stability and sustainability of the culture. The recycled explants were able to give a supplementary cell culture showing faster outgrowth, cleaner cell layers and higher net cell production. The cells exhibited a highly stabilized profile for marker gene expression including a low cytokeratin 49 (epithelial marker) and a high collagen 1a1 (mesenchymal marker) expression. Added to the cell spindle-shaped morphology, motility behavior, and actin organization, this suggests that the cells bore stable mesenchymal characteristics. This contrast with the time-evolving expression pattern observed in the control fresh explants during the first 2 weeks of culture: a sharp decrease in cytokeratin 49 expression was concomitant with a gradual increase in col1a1. We surmise that such loss of epithelial features for the benefit of mesenchymal ones was triggered by an epithelial to mesenchymal transition (EMT) process or by way of a progressive population replacement process. Overall, our findings provide a comprehensive characterization of this new primary culture model bearing mesenchymal features and whose stability over culture time makes those cells good candidates for cell reprogramming prior to nuclear transfer, in a context of fish genome preservation. - Highlights: • Recycled fin explants outgrow cells bearing stable mesenchymal traits. • Cell production and quality is enhanced in the recycled explant culture system. • Fresh fin primary culture is highly variable and loose epithelial traits over time.

60 APPLIED LIFE SCIENCES↗

FHOD1 formin is upregulated in melanomas and modifies proliferation and tumor growth

The functional properties of actin-regulating formin proteins are diverse and in many cases cell-type specific. FHOD1, a formin expressed predominantly in cells of mesenchymal lineage, bundles actin filaments and participates in maintenance of cell shape, migration and cellular protrusions. FHOD1 participates in cancer-associated epithelial to mesenchymal transition (EMT) in oral squamous cell carcinoma and breast cancer. The role of FHOD1 in melanomas has not been characterized. Here, we show that FHOD1 expression is typically strong in cutaneous melanomas and cultured melanoma cells while the expression is low or absent in benign nevi. By using shRNA to knockdown FHOD1 in melanoma cells, we discovered that FHOD1 depleted cells are larger, rounder and have smaller focal adhesions and inferior migratory capacity as compared to control cells. Importantly, we found FHOD1 depleted cells to have reduced colony-forming capacity and attenuated tumor growth in vivo, a finding best explained by the reduced proliferation rate caused by cell cycle arrest. Unexpectedly, FHOD1 depletion did not prevent invasive growth at the tumor margins. These results suggest that FHOD1 participates in key cellular processes that are dysregulated in malignancy, but may not be essential for melanoma cell invasion.

60 APPLIED LIFE SCIENCES↗

A central role for cadherin signaling in cancer

Cadherins are homophilic adhesion molecules with important functions in cell-cell adhesion, tissue morphogenesis, and cancer. In epithelial cells, E-cadherin accumulates at areas of cell-cell contact, coalesces into macromolecular complexes to form the adherens junctions (AJs), and associates via accessory partners with a subcortical ring of actin to form the apical zonula adherens (ZA). As a master regulator of the epithelial phenotype, E-cadherin is essential for the overall maintenance and homeostasis of polarized epithelial monolayers. Its expression is regulated by a host of genetic and epigenetic mechanisms related to cancer, and its function is modulated by mechanical forces at the junctions, by direct binding and phosphorylation of accessory proteins collectively termed catenins, by endocytosis, recycling and degradation, as well as, by multiple signaling pathways and developmental processes, like the epithelial to mesenchymal transition (EMT). Nuclear signaling mediated by the cadherin associated proteins β-catenin and p120 promotes growth, migration and pluripotency. Receptor tyrosine kinase, PI3K/AKT, Rho GTPase, and HIPPO signaling, are all regulated by E-cadherin mediated cell-cell adhesion. Finally, the recruitment of the microprocessor complex to the ZA by PLEKHA7, and the subsequent regulation of a small subset of miRNAs provide an additional mechanism by which the state of epithelial cell-cell adhesion affects translation of target genes to maintain the homeostasis of polarized epithelial monolayers. Collectively, the data indicate that loss of E-cadherin function, especially at the ZA, is a common and crucial step in cancer progression. - Highlights: • General review of the cadherin-catenin complex. • Nuclear signaling events regulated by β-catenin, p120, and E-cadherin. • Cadherin dysfunction in cancer. • Crosstalk between cadherin complexes and the RNAi machinery.

60 APPLIED LIFE SCIENCES↗

MRTF-A-miR-206-WDR1 form feedback loop to regulate breast cancer cell migration

Breast cancer is the leading cause of cancer death in women worldwide which is closely related to metastasis. Our previous study has shown that MRTF-A promote the migration of MDA-MB-231 cells and WDR1 promotes breast cancer cell migration. But the exact molecular mechanism on metastasis is still not fully understood, we now report that WDR1 enhanced the effect of MRTF-A induced-MDA-MB-231 cell migration by promoting the expression of the EMT markers and migration markers via RhoA-MRTF-A signaling pathway. Importantly, WDR1 promoted the nuclear importion of MRTF-A by affecting the expression of nuclear transport protein importin. But WDR1 did not affect the expression of MRTF-A. Interestingly, MRTF-A promoted the expression of miR-206 via its promoter CArG box but miR-206 inhibits the migration of breast cancer cells through suppressing the expression of WDR1 and MRTF-A via targeted their 3′UTR. Our data thus provide important and novel insights into MRTF-A-miR-206-WDR1 form feedback loop to regulate breast cancer cell migration. - Highlights: • WDR1 enhanced the effect of MRTF-A induced cell migration via RhoA-MRTF-A signaling pathway. • WDR1 promoted the nuclear importion of MRTF-A. • MRTF-A promoted the expression of miR-206 via its promoter CArG box. • miR-206 inhibits cell migration through suppressing the expression of WDR1 and MRTF-A. • MRTF-A-miR-206-WDR1 form feedback loop to regulate breast cancer cell migration.

60 APPLIED LIFE SCIENCES↗

Morphomechanical and structural changes induced by ROCK inhibitor in breast cancer cells

The EMT phenomenon is based on tumour progression. The cells lose their physiologic phenotype and assumed a mesenchymal phenotype characterized by an increased migratory capacity, invasiveness and high resistance to apoptosis. In this process, RHO family regulates the activation or suppression of ROCK (Rho-associated coiled-coil containing protein kinase) which in turn regulates the cytoskeleton dynamics. However, while the biochemical mechanisms are widely investigated, a comprehensive and careful estimation of biomechanical changes has not been extensively addressed. In this work, we used a strong ROCK inhibitor, Y-27632, to evaluate the effects of inhibition on living breast cancer epithelial cells by a biomechanical approach. Atomic Force Microscopy (AFM) was used to estimate changes of cellular elasticity, quantified by Young's modulus parameter. The morphometric alterations were analyzed by AFM topographies and Confocal Laser Scanning Microscopy (CLSM). Our study revealed a significant modification in the Young's modulus after treatment, especially as regards cytoskeletal region. Our evidences suggest that the use of Y-27632 enhanced the cell rigidity, preventing cell migration and arrested the metastasization process representing a potential powerful factor for cancer treatment. - Highlights: • RHO family regulated the activation or suppression of ROCK (Rho-associated protein kinase). • ROCK inhibitor (Y-2763) modified the Young Modulus's in the cytoskeletal region. • Y-2763 enhanced the cell rigidity and arrested metestatisation process. • Rock inhibitor reduction of cell elasticity envisaged novel antitumor therapies.

60 APPLIED LIFE SCIENCES↗

Protein arginine methyltransferase 1 coordinates the epithelial-mesenchymal transition/proliferation dichotomy in gastric cancer cells

Protein arginine methyltransferase 1 (PRMT1) is up-regulated and promotes migration, invasion and proliferation in wide range of cancers. However, we for the first time identify that PRMT1 promotes migration and invasion and inhibits proliferation in gastric cancer cells, a phenomenon called “migration-proliferation dichotomy”. First, we find that PRMT1 overexpression promotes migration and invasion and inhibits proliferation, whereas PRMT1 knockdown reverses the above abilities. Next, PRMT1 reduces the expression of epithelial marker E-cadherin and increases the expression of mesenchymal markers including N-cadherin, Vimentin, snail and β-catenin in gastric cancer cells. Furthermore, our studies show that PRMT1 silencing promotes the phosphorylation of LATS1, and then induces YAP phosphorylation, while overexpression of PRMT1 down-regulates the phosphorylation of LATS1 and YAP, indicating that PRMT1 inhibits EMT probably via Hippo signaling. Collectively, the present study reveals important roles of PRMT1 in progression of gastric cancer. Given the dual functions of PRMT1, it is as a potential drug target of gastric cancer with extreme caution.

60 APPLIED LIFE SCIENCES↗

SPARC is down-regulated by DNA methylation and functions as a tumor suppressor in T-cell lymphoma

Highlights: • SPARC is significantly down-regulated in T-NHL tissues and cell lines. • High levels of SPARC demonstrated a favorable clinical outcome. • SPARC inhibits proliferation, invasion and migration, but promotes apoptosis of T-NHL cells. • 5-Aza-Cdr inhibits proliferation, invasion and migration, but promotes apoptosis of T-NHL cells. The aim of this study was to assess the functional role of SPARC in T-cell non-Hodgkin's lymphoma (T-NHL), as well as the underlying molecular mechanisms. Here, we first identified SPARC expression in T-NHL tissues and cell lines through western blot and real-time PCR (RT-PCR). Overall survival of T-NHL patients with different levels of SPARC was assessed by Kaplan-Meier survival curves. Then cell proliferation, apoptosis, migration and invasion of T-NHL cells with either knockdown or overexpression of SPARC were determined by MTT, flow cytometry, transwell migration and invasion assay, respectively. Finally, the molecular mechanism by which SPARC modulated T-NHL cell progression was assessed. We confirmed that SPARC was significantly down-regulated in T-NHL tissues and cell lines. T-NHL patients with high levels of SPARC demonstrated a favorable clinical outcome. SPARC significantly suppressed cell proliferation, migration and invasion, and EMT process, but facilitated cell apoptosis in T-NHL cells. Further, we found that loss of SPARC expression in T-NHL tissues and cell lines, both in mRNA and protein levels, was associated with the aberrant DNA methylation in SPRAC gene, and the disrupted SPARC expression could be rescued after treatment with the demethylating agent 5-Aza-2′-deoxycitydine (5-Aza-Cdr). Additionally, 5-Aza-Cdr reversed SPARC hypermethylation to restore its biological role as a tumor suppressor in T-NHL cells, including inhibiting cell proliferation, invasion and migration, while promoting cell apoptosis. Our data provided evidence that DNA methylation in SPARC gene may play a role in the progression of T-NHL.

60 APPLIED LIFE SCIENCES↗

CHD4-mediated loss of E-cadherin determines metastatic ability in triple-negative breast cancer cells

Highlights: • CHD4 is associated with poor prognosis in triple-negative breast cancer patients. • Increased CHD4 is positively correlated with cell motility and drug resistance of TNBC cells. • CHD4 should be a potential prognostic biomarker in TNBC patient survival. Triple-negative breast cancer (TNBC) is a subtype of cancer with aggressive behaviors (high recurrence and metastasis rate) and poor prognosis. Therefore, studying the determining factors that lead to malignant TNBCs is necessary to develop personalized therapy and improve survival rates. In this study, we first analyzed levels of chromodomain helicase DNA binding protein 4 (CHD4) in 60 TNBC patients by immunohistochemical staining. We then clarified the role of CHD4 in TNBC and non-TNBC cell lines. Our clinical data indicated that higher CHD4 expression is positively correlated with metastatic stage, tumor recurrence, and survival status. Consistent with the clinical analytical data, our in vitro data also indicated that high level of CHD4 is positively correlated with malignant behaviors in TNBC cells, such as cell motility and mortality. For further analyses, we found that E-cadherin, N-cadherin and fibronetin are involved in CHD4-mediated epithelial-mesenchymal transition (EMT). Silencing of CHD4 also increased drug sensitivity to cisplatin and PARP1 inhibitor, especially in TNBC cells. Altogether, our findings showed that CHD4 is not only a potential prognostic biomarker for TNBC patient survival, but is also a powerful candidate in the development of new anti-cancer agents in TNBC.

60 APPLIED LIFE SCIENCES↗

Silencing of Kangai 1 C-terminal interacting tetraspanin suppresses progression of cholangiocarcinoma

Highlights: • KITENIN is expressed in murine and human cholangiocarcinoma (CC). • Knockdown of KITENIN reduced proliferation, migration, invasion and colony formation in CC cells. • Silencing of KITENIN inhibited the expression of epithelial-mesenchymal transition markers. • Targeting of KITENIN might function as a new therapeutic strategy against CC. Cholangiocarcinoma (CC) is the second most common primary hepatic malignancy. CC treatment options are very limited especially for patients with distant metastasis. Kangai 1 C-terminal interacting tetraspanin (KITENIN) is highly expressed in numerous cancers, but the role of KITENIN in CC remains unknown. Here, we have investigated for the first time the function of KITENIN in human CC cell lines (TFK-1, SZ-1), tissues and a CC mouse model (Alb-Cre/LSL-KRAS{sup G12D}/p53{sup L/L}). KITENIN was expressed in 92.2% of human CC tissues, in murine CC samples and also in human CC cell lines. Knockdown of KITENIN by small interfering RNA (siRNA) effectively reduced proliferation, migration, invasion and colony formation in both intra- and extra-hepatic CC cells. The expression of epithelial-mesenchymal transition (EMT) markers like N-cadherin, Vimentin, Snail and Slug were suppressed in KITENIN knockdown CC cells. Our results indicate that KITENIN is crucial for cholangiocarcinogenesis and it might become a potential therapeutic target for human CC treatment.

60 APPLIED LIFE SCIENCES↗

Hypoxia-induced HMGB1 expression of HCC promotes tumor invasiveness and metastasis via regulating macrophage-derived IL-6

Highlights: • Hypoxia heightens HMGB1 expression in HCC via HIF1α. • Elevated HMGB1 exacerbates macrophage infiltration into tumor under hypoxia. • Macrophage-derived IL-6 promotes EMT of HCC cells under hypoxia. • Inhibition of HMGB1 attenuates tumor metastasis and macrophage infiltration. Hypoxia is associated with the progression of hepatocellular carcinoma through promotion of spontaneous metastasis but the mechanism remains unclear. Here, we hypothesis that tumor cell-derived HMGB1 orchestrates macrophages infiltration and promotes metastasis of HCC via enhancing macrophage-secreted IL-6 under hypoxia. HMGB1 expression was robustly exacerbated in tumors of HCC patients with PVTT. Meanwhile, hypoxia exposure gave rise to HMGB1 expression in hepatoma cells of human and mouse in a HIF-1α-dependent manner and subsequently induced the infiltration and reprogramming of macrophages to augment the expression of Il-6. Further study demonstrated macrophage-derived IL-6 enhanced the invasiveness and metastasis of murine HCC cells. Therefore, our study provides a novel understanding of the relationship between tumor cells and tumor associated macrophages (TAMs) in the context of hypoxia.

60 APPLIED LIFE SCIENCES↗