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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 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
DOE OSTI2015

Sulforaphane, a cancer chemopreventive agent, induces pathways associated with membrane biosynthesis in response to tissue damage by aflatoxin B{sub 1}

Aflatoxin B{sub 1} (AFB{sub 1}) is one of the major risk factors for liver cancer globally. A recent study showed that sulforaphane (SF), a potent inducer of phase II enzymes that occurs naturally in widely consumed vegetables, effectively induces hepatic glutathione S-transferases (GSTs) and reduces levels of hepatic AFB{sub 1}-DNA adducts in AFB{sub 1}-exposed Sprague Dawley rats. The present study characterized the effects of SF pre-treatment on global gene expression in the livers of similarly treated male rats. Combined treatment with AFB{sub 1} and SF caused reprogramming of a network of genes involved in signal transduction and transcription. Changes in gene regulation were observable 4 h after AFB{sub 1} administration in SF-pretreated animals and may reflect regeneration of cells in the wake of AFB{sub 1}-induced hepatotoxicity. At 24 h after AFB{sub 1} administration, significant induction of genes that play roles in cellular lipid metabolism and acetyl-CoA biosynthesis was detected in SF-pretreated AFB{sub 1}-dosed rats. Induction of this group of genes may indicate a metabolic shift toward glycolysis and fatty acid synthesis to generate and maintain pools of intermediate molecules required for tissue repair, cell growth and compensatory hepatic cell proliferation. Collectively, gene expression data from this study provide insights into molecular mechanisms underlying the protective effects of SF against AFB{sub 1} hepatotoxicity and hepatocarcinogenicity, in addition to the chemopreventive activity of this compound as a GST inducer. - Highlights: • This study revealed sulforaphane (SF)-deregulated gene sets in aflatoxin B{sub 1} (AFB{sub 1})-treated rat livers. • SF redirects biochemical networks toward lipid biosynthesis in AFB{sub 1}-dosed rats. • SF enhanced gene sets that would be expected to favor cell repair and regeneration.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Curcumin enhances recovery of pancreatic islets from cellular stress induced inflammation and apoptosis in diabetic rats

The phytochemical, curcumin, has been reported to play many beneficial roles. However, under diabetic conditions, the detail mechanism of its beneficial action in the glucose homeostasis regulatory organ, pancreas, is poorly understood. The present study has been designed and carried out to explore the role of curcumin in the pancreatic tissue of STZ induced and cellular stress mediated diabetes in eight weeks old male Wistar rats. Diabetes was induced with a single intraperitoneal dose of STZ (65 mg/kg body weight). Post to diabetes induction, animals were treated with curcumin at a dose of 100 mg/kg body weight for eight weeks. Underlying molecular and cellular mechanism was determined using various biochemical assays, DNA fragmentation, FACS, histology, immunoblotting and ELISA. Treatment with curcumin reduced blood glucose level, increased plasma insulin and mitigated oxidative stress related markers. In vivo and in vitro experimental results revealed increased levels of proinflammatory cytokines (TNF-α, IL1-β and IFN-γ), reduced level of cellular defense proteins (Nrf-2 and HO-1) and glucose transporter (GLUT-2) along with enhanced levels of signaling molecules of ER stress dependent and independent apoptosis (cleaved Caspase-12/9/8/3) in STZ administered group. Treatment with curcumin ameliorated all the adverse changes and helps the organ back to its normal physiology. Results suggest that curcumin protects pancreatic beta-cells by attenuating inflammatory responses, and inhibiting ER/mitochondrial dependent and independent pathways of apoptosis and crosstalk between them. This uniqueness and absence of any detectable adverse effect proposes the possibility of using this molecule as an effective protector in the cellular stress mediated diabetes mellitus. - Highlights: • STZ induced cellular stress plays a vital role in pancreatic dysfunction. • Cellular stress causes inflammation, pancreatic islet cell death and diabetes. • Deregulation of Nrf-2 mediated antioxidant defense machinery takes place. • Islet cells undergo apoptosis (via ER/mitochondrial dependent/independent pathways). • Curcumin protects pancreatic β-cells from the adverse effects of cellular stress.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Tungsten-induced carcinogenesis in human bronchial epithelial cells

Metals such as arsenic, cadmium, beryllium, and nickel are known human carcinogens; however, other transition metals, such as tungsten (W), remain relatively uninvestigated with regard to their potential carcinogenic activity. Tungsten production for industrial and military applications has almost doubled over the past decade and continues to increase. Here, for the first time, we demonstrate tungsten's ability to induce carcinogenic related endpoints including cell transformation, increased migration, xenograft growth in nude mice, and the activation of multiple cancer-related pathways in transformed clones as determined by RNA sequencing. Human bronchial epithelial cell line (Beas-2B) exposed to tungsten developed carcinogenic properties. In a soft agar assay, tungsten-treated cells formed more colonies than controls and the tungsten-transformed clones formed tumors in nude mice. RNA-sequencing data revealed that the tungsten-transformed clones altered the expression of many cancer-associated genes when compared to control clones. Genes involved in lung cancer, leukemia, and general cancer genes were deregulated by tungsten. Taken together, our data show the carcinogenic potential of tungsten. Further tests are needed, including in vivo and human studies, in order to validate tungsten as a carcinogen to humans. - Highlights: • Tungsten (W) induces cell transformation and increases migration in vitro. • W increases xenograft growth in nude mice. • W altered the expression of cancer-related genes such as those involved in leukemia. • Some of the dysregulated leukemia genes include, CD74, CTGF, MST4, and HOXB5. • For the first time, data is presented that demonstrates tungsten's carcinogenic potential.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Doxorubicin: Comparison between 3-h continuous and bolus intravenous administration paradigms on cardio-renal axis, mitochondrial sphingolipids and pathology

Doxorubicin (DOX) is a potent and effective broad-spectrum anthracycline antitumor agent, but its clinical usefulness is restricted by cardiotoxicity. This study compared pharmacokinetic, functional, structural and biochemical effects of single dose DOX bolus or 3-h continuous iv infusion (3-h iv) in the Han–Wistar rat to characterize possible treatment-related differences in drug safety over a 72 h observation period. Both DOX dosing paradigms significantly altered blood pressure, core body temperature and QA interval (indirect measure of cardiac contractility); however, there was no recovery observed in the bolus iv treatment group. Following the 3-h iv treatment, blood pressures and QA interval normalized by 36 h then rose above baseline levels over 72 h. Both treatments induced biphasic changes in heart rate with initial increases followed by sustained decreases. Cardiac injury biomarkers in plasma were elevated only in the bolus iv treatment group. Tissue cardiac injury biomarkers, cardiac mitochondrial complexes I, III and V and cardiac mitochondrial sphingolipids were decreased only in the bolus iv treatment group. Results indicate that each DOX dosing paradigm deregulates sinus rhythm. However, slowing the rate of infusion allows for functional compensation of blood pressure and may decrease the likelihood of cardiac myocyte necrosis via a mechanism associated with reduced mitochondrial damage. - Highlights: • Despite damaging cardiomyocytes, continuous iv doxorubicin improves cardiovascular outcomes. • This study supports administration of doxorubicin via slow continuous iv infusion limits acute cardio-toxicity. • This study supports use of metabolomic-derived lipid biomarkers for improved quantification of cardiovascular risk. • This study supports systems-based physiological approach to generate a data that can greatly inform risk assessments.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

Toll-like receptor 4 is involved in the cell cycle modulation and required for effective human cytomegalovirus infection in THP-1 macrophages

Suitable host cell metabolic conditions are fundamental for the effective development of the human cytomegalovirus (HCMV) lytic cycle. Indeed, several studies have demonstrated the ability of this virus to interfere with cell cycle regulation, mainly by blocking proliferating cells in G1 or G1/S. In the present study, we demonstrate that HCMV deregulates the cell cycle of THP-1 macrophages (a cell line irreversibly arrested in G0) by pushing them into S and G2 phases. Moreover, we show that HCMV infection of THP-1 macrophages leads to Toll-like receptor 4 (TLR4) activation. Since various studies have indicated TLR4 to be involved in promoting cell proliferation, here we investigate the possible role of TLR4 in the observed HCMV-induced cell cycle perturbation. Our data strongly support TLR4 as a mediator of HCMV-triggered cell cycle activation in THP-1 macrophages favouring, in turn, the development of an efficient viral lytic cycle. - Highlights: ► We studied HCMV infection impact on THP-1 macrophage cell cycle. ► We analysed the role played by Toll-like receptor (TLR) 4 upon HCMV infection. ► HCMV pushes THP-1 macrophages (i.e. resting cells) to re-enter the cell cycle. ► TLR4 pathway inhibition strongly affects the effectiveness of HCMV replication. ► TLR4 pathway inhibition significantly decreases HCMV-induced cell cycle re-entry.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Acetylation of the c-MYC oncoprotein is required for cooperation with the HTLV-1 p30{sup II} accessory protein and the induction of oncogenic cellular transformation by p30{sup II}/c-MYC

The human T-cell leukemia retrovirus type-1 (HTLV-1) p30{sup II} protein is a multifunctional latency-maintenance factor that negatively regulates viral gene expression and deregulates host signaling pathways involved in aberrant T-cell growth and proliferation. We have previously demonstrated that p30{sup II} interacts with the c-MYC oncoprotein and enhances c-MYC-dependent transcriptional and oncogenic functions. However, the molecular and biochemical events that mediate the cooperation between p30{sup II} and c-MYC remain to be completely understood. Herein we demonstrate that p30{sup II} induces lysine-acetylation of the c-MYC oncoprotein. Acetylation-defective c-MYC Lys→Arg substitution mutants are impaired for oncogenic transformation with p30{sup II} in c-myc{sup −/−} HO15.19 fibroblasts. Using dual-chromatin-immunoprecipitations (dual-ChIPs), we further demonstrate that p30{sup II} is present in c-MYC-containing nucleoprotein complexes in HTLV-1-transformed HuT-102 T-lymphocytes. Moreover, p30{sup II} inhibits apoptosis in proliferating cells expressing c-MYC under conditions of genotoxic stress. These findings suggest that c-MYC-acetylation is required for the cooperation between p30{sup II}/c-MYC which could promote proviral replication and contribute to HTLV-1-induced carcinogenesis. - Highlights: • Acetylation of c-MYC is required for oncogenic transformation by HTLV-1 p30{sup II}/c-MYC. • Acetylation-defective c-MYC mutants are impaired for foci-formation by p30{sup II}/c-MYC. • The HTLV-1 p30{sup II} protein induces lysine-acetylation of c-MYC. • p30{sup II} is present in c-MYC nucleoprotein complexes in HTLV-1-transformed T-cells. • HTLV-1 p30{sup II} inhibits apoptosis in c-MYC-expressing proliferating cells.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2010

MicroRNA-15a fine-tunes the level of Delta-like 1 homolog (DLK1) in proliferating 3T3-L1 preadipocytes

Delta like 1 homolog (Dlk1) exists in both transmembrane and soluble molecular forms, and is implicated in cellular growth and plays multiple roles in development, tissue regeneration, and cancer. Thus, DLK1 levels are critical for cell function, and abnormal DLK1 expression can be lethal; however, little is known about the underlying mechanisms. We here report that miR-15a modulates DLK1 levels in preadipocytes thus providing a mechanism for DLK1 regulation that further links it to cell cycle arrest and cancer since miR-15a is deregulated in these processes. In preadipocytes, miR-15a increases with cell density, and peaks at the same stage where membrane DLK1{sup M} and soluble DLK1{sup S} are found at maximum levels. Remarkably, miR-15a represses the amount of all Dlk1 variants at the mRNA level but also the level of DLK1{sup M} protein while it increases the amount of DLK1{sup S} supporting a direct repression of DLK1 and a parallel effect on the protease that cleaves off the DLK1 from the membrane. In agreement with previous studies, we found that miR-15a represses cell numbers, but additionally, we report that miR-15a also increases cell size. Conversely, anti-miR-15a treatment decreases cell size while increasing cell numbers, scenarios that were completely rescued by addition of purified DLK1{sup S}. Our data thus imply that miR-15a regulates cell size and proliferation by fine-tuning Dlk1 among others, and further emphasize miR-15a and DLK1 levels to play important roles in growth signaling networks.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2012

Intricacies of hedgehog signaling pathways: A perspective in tumorigenesis

The hedgehog (HH) signaling pathway is a crucial negotiator of developmental proceedings in the embryo governing a diverse array of processes including cell proliferation, differentiation, and tissue patterning. The overall activity of the pathway is significantly curtailed after embryogenesis as well as in adults, yet it retains many of its functional capacities. However, aberration in HH signaling mediates the initiation, proliferation and continued sustenance of malignancy in different tissues to varying degrees through different mechanisms. In this review, we provide an overview of the role of constitutively active aberrant HH signaling pathway in different types of human cancer and the underlying molecular and genetic mechanisms that drive tumorigenesis in that particular tissue. An insight into the various modes of anomalous HH signaling in different organs will provide a comprehensive knowledge of the pathway in these tissues and open a window for individually tailored, tissue-specific therapeutic interventions. The synergistic cross talking of HH pathway with many other regulatory molecules and developmentally inclined signaling pathways may offer many avenues for pharmacological advances. Understanding the molecular basis of abnormal HH signaling in cancer will provide an opportunity to inhibit the deregulated pathway in many aggressive and therapeutically challenging cancers where promising options are not available.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

Rap G protein signal in normal and disordered lymphohematopoiesis

Rap proteins (Rap1, Rap2a, b, c) are small molecular weight GTPases of the Ras family. Rap G proteins mediate diverse cellular events such as cell adhesion, proliferation, and gene activation through various signaling pathways. Activation of Rap signal is regulated tightly by several specific regulatory proteins including guanine nucleotide exchange factors and GTPase-activating proteins. Beyond cell biological studies, increasing attempts have been made in the past decade to define the roles of Rap signal in specific functions of normal tissue systems as well as in cancer. In the immune and hematopoietic systems, Rap signal plays crucial roles in the development and function of essentially all lineages of lymphocytes and hematopoietic cells, and importantly, deregulated Rap signal may lead to unique pathological conditions depending on the affected cell types, including various types of leukemia and autoimmunity. The phenotypical studies have unveiled novel, even unexpected functional aspects of Rap signal in cells from a variety of tissues, providing potentially important clues for controlling human diseases, including malignancy.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

The cytoskeletal inhibitors latrunculin A and blebbistatin exert antitumorigenic properties in human hepatocellular carcinoma cells by interfering with intracellular HuR trafficking

The impact of the RNA-binding protein HuR for the post-transcriptional deregulation of tumor-relevant genes is well established. Despite of elevations in HuR expression levels, an increase in cytoplasmic HuR abundance in many cases correlates with a high grade of malignancy. Here, we demonstrated that administration of the actin-depolymerizing macrolide latrunculin A, or blebbistatin, an inhibitor of myosin II ATPase activity, caused a dose- and time-dependent reduction in the high cytoplasmic HuR content of HepG2 and Huh7 hepatocellular carcinoma (HCC) cells. Subcellular fractionation revealed that in addition, both inhibitors strongly attenuated cytoskeletal and membrane-bound HuR abundance and conversely increased the HuR amount in nuclear cell fractions. Concomitant with changes in intracellular HuR localization, both cytoskeletal inhibitors markedly decreased the half-lives of cyclooxygenase-2 (COX-2), cyclin A and cyclin D{sub 1} encoding mRNAs resulting in a significant reduction in their expression levels in HepG2 cells. Importantly, a similar reduction in the expression of these HuR targets was achieved by a RNA interference (RNAi)-mediated knockdown of either HuR or nonmuscle myoin IIA. Using polysomal fractionation, we further demonstrate that the decrease in cytoplasmic HuR by latrunculin A or blebbistatin is accompanied by a marked change in the allocation of HuR and its mRNA cargo from polysomes to ribonucleoprotein (RNP) particles. Functionally, the basal migration and prostaglandin E{sub 2} synthesis are similarly impaired in inhibitor-treated and stable HuR-knockdown HepG2 cells. Our data demonstrate that interfering with the actomyosin-dependent HuR trafficking may comprise a valid therapeutic option for antagonizing pathologic posttranscriptional gene expression by HuR and furthermore emphasize the potential benefit of HuR inhibitory strategies for treatment of HCC. - Highlights: • We tested the effects of latrunculin A and blebbistatin on different HuR activities. • Both cytoskeletal inhibitors disturbed the RNP-polysome HuR allocation in HepG2 cells. • Accordingly, both inhibitors reduced the stability and levels of HuR controlled mRNAs. • Functionally, important HuR-triggered cell functions were impaired by both compounds. • Targeting of HuR trafficking implies a useful approach for novel antitumor therapy.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Epigenetic regulation of hematopoietic stem cell aging

Aging is invariably associated with alterations of the hematopoietic stem cell (HSC) compartment, including loss of functional capacity, altered clonal composition, and changes in lineage contribution. Although accumulation of DNA damage occurs during HSC aging, it is unlikely such consistent aging phenotypes could be solely attributed to changes in DNA integrity. Another mechanism by which heritable traits could contribute to the changes in the functional potential of aged HSCs is through alterations in the epigenetic landscape of adult stem cells. Indeed, recent studies on hematopoietic stem cells have suggested that altered epigenetic profiles are associated with HSC aging and play a key role in modulating the functional potential of HSCs at different stages during ontogeny. Even small changes of the epigenetic landscape can lead to robustly altered expression patterns, either directly by loss of regulatory control or through indirect, additive effects, ultimately leading to transcriptional changes of the stem cells. Potential drivers of such changes in the epigenetic landscape of aged HSCs include proliferative history, DNA damage, and deregulation of key epigenetic enzymes and complexes. This review will focus largely on the two most characterized epigenetic marks – DNA methylation and histone modifications – but will also discuss the potential role of non-coding RNAs in regulating HSC function during aging.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Osteoprotegerin activates osteosarcoma cells that co-express RANK and RANKL

Background: Osteosarcoma (OS) is an aggressive and often fatal cancer that afflicts over 1000 humans and 10,000 dogs per year in the United States. Recent evidence suggests deregulation in the signaling triad, receptor activator of nuclear factor kappa B (RANK), its activating ligand (RANKL), and the RANKL inhibitor, osteoprotegerin (OPG) plays a key role in the pathogenesis of OS. This study investigated the expression of RANK and RANKL in osteosarcoma tumors and cell lines and describes an activating effect of OPG on OS cells in vitro. Results: Canine OS tumors and cell lines co-express mRNA for both RANK and RANKL. Expression of these proteins in OS cell lines was confirmed by Western blot and immunofluorescence microscopy. Expression of the soluble form of RANKL was not detected in media from OS cells. OPG-Fc incubation increased the phosphorylation status of ERK, AKT and the p65 subunit of nuclear factor kappa B (NFκB) and induced NFκB translocation from the cytoplasm to the nucleus in canine OS cells. OPG increased proliferation in both canine and human derived OS cell lines. Conclusion: RANKL is produced by OS tumors and cell lines that also express RANK. This data provides preliminary evidence for a potential autocrine and or paracrine activation pathway in canine OS. An activating effect of exogenous OPG on signal transduction proteins, NFκB and proliferation in OS is described. These data provide new information concerning aberrant signaling in OS and could be important to those considering OPG as a therapeutic agent for osteosarcoma. - Highlights: • Osteosarcoma cells express receptor activator of NFκ-B (RANK) and its ligand RANKL. • Osteoprotegrin (OPG) activates ERK, AKT and NFκB in canine osteosarcoma cells. • Osteoprotegrin incubation causes an increase in total NFκB and phosphorylated NFκB in the nucleus. • Osteoprotegrin increases proliferation in canine and human osteosarcoma cells independent of exogenous RANKL.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

The β-catenin signaling pathway induces aggressive potential in breast cancer by up-regulating the chemokine CCL5

β-Catenin signaling plays a pivotal role in the genesis of a variety of malignant tumors, but its role in breast cancer has not been fully elucidated. Here, we examined whether deregulation of β-catenin signaling is related to the aggressive characteristics of certain types of breast cancers. Analysis of cytokine levels in MDA-MB-231 cells overexpressing a constitutively active form of β-catenin (CAβ-catenin) revealed a higher level of CCL5 expression. Cells transfected with CAβ-catenin or stimulated with recombinant CCL5 exhibited increased cell invasion activity and spheroid formation in vitro. Furthermore, CAβ-catenin-transfected MDA-MB-231 cells formed larger tumor masses that contained more Ki-67-positive cells and infiltrating lymphocytes than did the control cells. An inhibitor of CCR5 and a pan-CXCR neutralizing antibody dramatically reduced CAβ-catenin-promoted activities. In addition to CCL5, 6-BIO, a chemical activator of β-catenin, induced cell invasion and spheroid formation in MDA-MB-231 cells. Furthermore, high levels of nuclear β-catenin accumulation were detected in breast cancer in patients with metastasis but not in those without metastasis. Nuclear β-catenin localization is related to increased CCL5 production in breast cancer. These findings suggest that β-catenin expression enhances tumor progression via chemokine production in breast cancers and that β-catenin signaling is a critical regulator of the aggressive traits of breast cancers. - Highlights: •The expression of chemokines, especially CCL5, is positively regulated by β-catenin signaling •The inhibition of CCR5 signaling suppressed β-catenin-induced tumor spreading in vitro and in vivo. • β-catenin was detected in cell nuclei in specimens from carcinoma regions of metastasized breast cancer • β-catenin nuclear translocation and cytokines have implications in leading to metastasis events.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Enhanced expression of CD31/platelet endothelial cell adhesion molecule 1 (PECAM1) correlates with hypoxia inducible factor-1 alpha (HIF-1α) in human glioblastoma multiforme

Glioblastoma multiforme (GBM) is characterized by numerous abnormal blood vessels, which rapidly proliferate and invade brain tissue and express different angiogenic factors. In this study we have investigated whether the expression levels of CD31/ PECAM1 are deregulated in human GBM tissue specimens and we have also correlated the expression levels of CD31/PECAM1 with those of HIF-1α. Finally, we have established a correlation between the expression levels of CD31/PECAM1 and HIF-1α, and those of two other biomarkers, namely N-cadherin and ADAM-10, of aggressiveness in the same tumors. Results have shown an increased expression of CD31/PECAM1 correlated to HIF-1α expression, confirming evidence demonstrating that different types of tumor are able to trigger aberrant angiogenesis through HIF-1α. Moreover, we also established a further correlation among CD31/PECAM1 and HIF-1α and N-cadherin and ADAM-10, two other markers of aggressiveness in the same tumors.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Apoptosis in human myelodysplastic syndrome CD34+ cells is modulated by the upregulation of TLRs and histone H4 acetylation via a β-arrestin 1 dependent mechanism

Excessive apoptosis of hematopoietic precursors in the bone marrow underlies the ineffective hematopoiesis characteristic of myelodysplastic syndrome (MDS). Toll-like receptor (TLR) signaling is abnormally activated in MDS and may be involved in excessive programmed cell death in the pathogenesis of MDS. TLRs expression and global histone H3/H4 acetylation were analyzed in bone marrow (BM) CD34+ cells from 20 lower-risk and 20 higher-risk MDS patients and 10 healthy controls. Apoptosis of BM CD34+ cells was examined by flow cytometry, and its correlation to histone acetylation and the expression of TLR2 and β-arrestin1 (β-arr1), measured by enzyme-linkedimmunosorbent assay and qRT-PCR, was assessed. TLR1, TLR2 and TLR6 expression and H4 acetylation levels were higher in lower-risk MDS patients than in higher-risk MDS patients or controls, and TLR2 expression and H4 acetylation levels were positively correlated with an increased rate of apoptosis. Lower-risk MDS was associated with increased β-arr1 expression and histone acetyltransferase p300 activity. In in vitro-cultured primary normal and lower-risk MDS CD34+ cells, TLR2 activation-induced apoptosis was mediated by the upregulation of β-arr1 leading to the recruitment of p300 and increased histone H4 acetylation. The nuclear accumulation of βarr1 following TLR2 activation promote H4 acetylation at specific target gene promoters and may thus affect transcription of target genes in BM CD34+ cells. The mechanisms underlying the deregulation of TLR2 and increased apoptosis in MDS may involve the β-arr1 mediated recruitment of p300 leading to increased levels of histone H4 acetylation. - Highlights: • TLR2 is upregulated in lower-risk MDS patients. • TLR2 expression and H4 acetylation correlated with increased CD34+ cell apoptosis. • TLR2-induced apoptosis was mediated by β-arr1 upregulation in normal CD34+ cells. • β-arr1 mediated recruitment of p300 lead to increased histone H4 acetylation levels.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Toll-like receptor 4 promotes angiogenesis in pancreatic cancer via PI3K/AKT signaling

Deregulation of Toll-like receptor 4 (TLR4) is closely associated with the progression of various types of cancers, but its role in pancreatic carcinogenesis is unclear. This study aimed to investigate the role of TLR4 in the angiogenesis of pancreatic cancer and the underlying molecular mechanisms. The culture supernatant (conditioned medium) of PANC-1 cells after appropriate treatment was used for the treatment of HUVECs. The proliferation, migration and tube formation of HUVECs were assessed by MTT, Transwell and Matrigel, respectively. In pancreatic cancer tissues, TLR4, VEGF and CD31 were upregulated as determined by immunohistochemistry and the expression of TLR4 and VEGF was positively correlated with microvessel density as detected by CD31 staining. Activation of TLR4 signaling by LPS in PANC-1 cells resulted in increased VEGF and phosphorylation of AKT, which were abolished by TLR4 silencing with siRNA and PI3K/AKT signaling inhibitor LY294002. The conditioned medium from PANC-1 cells treated with LY294002 or transfected with TRL4 siRNA reduced the proliferation, migration and tube formation of HUVECs. In contrast, the conditioned medium from PANC-1 cells treated with LPS stimulated the proliferation, migration and tube formation of HUVECs, which was however significantly inhibited by pretreatment of PANC-1 cells with LY294002 or transfection with TRL4 siRNA. Our findings suggest TLR4 may promote angiogenesis in pancreatic cancer by activating the PI3K/AKT signaling pathway to induce VEGF expression.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Distinct hydrophobic “patches” in the N- and C-tails of beta-catenin contribute to nuclear transport

β-catenin is a key mediator of Wnt signaling and its deregulated nuclear accumulation can drive cancer progression. While the central armadillo (Arm) repeats of β-catenin stimulate nuclear entry, the N- and C-terminal “tail” sequences are thought to regulate turnover and transactivation. We show here that the N- and C-tails are also potent transport sequences. The unstructured tails of β-catenin, when individually fused to a GFP-reporter, could enter and exit the nucleus rapidly in live cells. Proximity ligation assays and pull-down assays identified a weak interaction between the tail sequences and the FG-repeats of nucleoporins, consistent with a possible direct translocation of β-catenin through the nuclear pore complex. Extensive alanine mutagenesis of the tail sequences revealed that nuclear translocation of β-catenin was dependent on specific uniformly distributed patches of hydrophobic residues, whereas the mutagenesis of acidic amino acids had no effect. Moreover, the mutation of hydrophobic patches within the N-tail and C-tail of full length β-catenin reduced nuclear transport rate and diminished its ability to activate transcription. We propose that the tail sequences can contribute to β-catenin transport and suggest a possible similar role for hydrophobic unstructured regions in other proteins. - Highlights: • We show that the N- and C-tails of beta-catenin possess nuclear transport activity. • Nuclear transport of the N- or C-tails requires specific hydrophobic amino acids. • Mutagenesis of the N-terminus diminished nuclear entry of full-length beta-catenin. • We propose the N-tail contributes to beta-catenin nuclear entry and transactivation.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

miR-429 inhibits metastasis by targeting KIAA0101 in Soft Tissue Sarcoma

Soft tissue sarcomas (STS) are a heterogeneous group of rare tumors with high metastatic potential. There being only a handful of publication on metastasis of STS, we investigated the miRNA mediated target gene regulations in modulating the metastatic processes in this cancer. In this study, we amalgamated gene and miRNA expression profiles of high-grade STS samples with miRNA target predictions and identified miR-429 targeting KIAA0101 as a novel pair, which remain unexplored in STS metastasis. We validated their expression in metastatic fibrosarcoma cell line, HT1080 and performed several functional assays using miRNA mimics and KIAA0101 over-expression vector to confirm their role in metastasis. We observed miR-429 is downregulated in HT1080 cells and acting as an anti-metastatic miRNA that inhibited proliferation, migration, anchorage independent growth and invasion by de-repressing KIAA0101. Moreover, the renilla luciferase reporter assay confirmed that miR-429 targets KIAA0101 by binding to its 3{sup /}UTR and influence its expression. Taken together, our work demonstrated miR-429 mediates deregulation of KIAA0101 by acting as an anti-metastatic miRNA that targets KIAA0101 pro-metastatic gene during metastasis of STS. - Highlights: • miR-429 inhibits metastasis by targeting KIAA0101 in Soft Tissue Sarcoma. • miR-429 suppresses proliferation, migration, anchorage independent growth and invasion in HT1080. • We validated targeting of miR-429 and KIAA0101 by reporter assay. • KIAA0101 overexpression is involved in decreased survival of STS patients.

60 APPLIED LIFE SCIENCES↗