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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 829 records · Page 46
All sourcesNASA NTRSDOE OSTI
DOE OSTI2013

Capacity of wild-type and chemokine-armed parvovirus H-1PV for inhibiting neo-angiogenesis

Anti-angiogenic therapy has been recognized as a powerful potential strategy for impeding the growth of various tumors. However no major therapeutic effects have been observed to date, mainly because of the emergence of several resistance mechanisms. Among novel strategies to target tumor vasculature, some oncolytic viruses open up new prospects. In this context, we addressed the question whether the rodent parvovirus H-1PV can target endothelial cells. We show that cultures of human normal (HUVEC) and immortalized (KS-IMM) endothelial cells sustain an abortive viral cycle upon infection with H-1PV and are sensitive to H-1PV cytotoxicity. H-1PV significantly inhibits infected KS-IMM tumor growth. This effect may be traced back by the virus ability to both kill proliferating endothelial cells and inhibit VEGF production Recombinant H-1PV vectors can also transduce tumor cells with chemokines endowed with anti-angiogenesis properties, and warrant further validation for the treatment of highly vascularized tumors. - Highlights: • The oncolytic parvovirus H-1PV can target endothelial cells. • Abortive viral cycle upon infection of endothelial cells with H-1PV. • Inhibition of VEGF expression and KS-IMM tumor growth by H-1PV.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2012

Crosstalk between the peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}) and the vitamin D receptor (VDR) in human breast cancer cells: PPAR{gamma} binds to VDR and inhibits 1{alpha},25-dihydroxyvitamin D{sub 3} mediated transactivation

Heterodimerization and cross-talk between nuclear hormone receptors often occurs. For example, estrogen receptor alpha (ER{alpha}) physically binds to peroxisome proliferator-activated receptor gamma (PPAR{gamma}) and inhibits its transcriptional activity. The interaction between PPAR{gamma} and the vitamin D receptor (VDR) however, is unknown. Here, we elucidate the molecular mechanisms linking PPAR{gamma} and VDR signaling, and for the first time we show that PPAR{gamma} physically associates with VDR in human breast cancer cells. We found that overexpression of PPAR{gamma} decreased 1{alpha},25-dihydroxyvitamin D{sub 3} (1,25D{sub 3}) mediated transcriptional activity of the vitamin D target gene, CYP24A1, by 49% and the activity of VDRE-luc, a vitamin D responsive reporter, by 75% in T47D human breast cancer cells. Deletion mutation experiments illustrated that helices 1 and 4 of PPAR{gamma}'s hinge and ligand binding domains, respectively, governed this suppressive function. Additionally, abrogation of PPAR{gamma}'s AF2 domain attenuated its repressive action on 1,25D{sub 3} transactivation, indicating that this domain is integral in inhibiting VDR signaling. PPAR{gamma} was also found to compete with VDR for their binding partner retinoid X receptor alpha (RXR{alpha}). Overexpression of RXR{alpha} blocked PPAR{gamma}'s suppressive effect on 1,25D{sub 3} action, enhancing VDR signaling. In conclusion, these observations uncover molecular mechanisms connecting the PPAR{gamma} and VDR pathways. -- Highlights: PPAR{gamma}'s role on 1{alpha},25-dihydroxyvitamin D{sub 3} transcriptional activity is examined. Black-Right-Pointing-Pointer PPAR{gamma} physically binds to VDR and inhibits 1{alpha},25-dihydroxyvitamin D{sub 3} action. Black-Right-Pointing-Pointer PPAR{gamma}'s hinge and ligand binding domains are important for this inhibitory effect. Black-Right-Pointing-Pointer PPAR{gamma} competes with VDR for the availability of their binding partner, RXR{alpha}.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

Apolipoprotein E inhibits osteoclast differentiation via regulation of c-Fos, NFATc1 and NF-κB

Apolipoprotein E (ApoE) plays a major role in the transport and metabolism of lipid. Other functions of ApoE include modulation of innate and adaptive immune responses. The expression of ApoE in osteoblasts and its relevance with bone formation have also been reported. However, the effect of ApoE on osteoclasts has not yet been examined. Here, we investigated the role of ApoE in osteoclast differentiation using bone marrow-derived macrophages (BMMs) and RAW264.7 cells. We found a down-regulation of ApoE gene expression during osteoclastic differentiation of those cells. Overexpression of ApoE in BMMs and RAW264.7 cells significantly blocked the induction of c-Fos and nuclear factor of activated T cell c1 (NFATc1), transcription factors critical for expression of osteoclast marker genes, by receptor activator of nuclear factor κB ligand (RANKL), the osteoclast differentiation factor. ApoE inhibited osteoclast differentiation, as measured by decreased number of tartrate-resistant acid phosphatase (TRAP)-positive multinuclear cells (MNCs). In addition, ApoE reduced the expression of dendritic cell-specific transmembrane protein (DC-STAMP) and ATPase, H{sup +} transporting, lysosomal 38 kDa, V0 subunit d2 (ATP6v0d2), genes involved in cell–cell fusion during osteoclastogenesis. Knock-down of ApoE using a specific siRNA promoted the RANKL-mediated induction of osteoclast differentiation. While ApoE did not affect the activation of ERK, JNK, and p38 MAPK signaling pathways by RANKL, the phosphorylation of p65 trans-activation domain on serine 536 and transcription activity of NF-κB were reduced by ApoE overexpression. These findings suggest that ApoE plays an inhibitory role in osteoclast differentiation via the suppression of RANKL-dependent activation of NF-κB and induction of c-Fos and NFATc1. - Highlights: ► Apolipoprotein E (ApoE) significantly inhibited osteoclast differentiation and activation of NF-κB. ► ApoE decreased the induction of osteoclast marker genes such as c-Fos, NFATc1, TRAP, DC-STAMP and Cathepsin K. ► ApoE reduced number of TRAP-positive multinuclear cells. ► Exogenous ApoE inhibits osteoclast formation by reduction of crucial factor of osteoclast differentiation. ► knock-down of ApoE promoted the RANKL-mediated induction of osteoclast differentiation.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

Quercetin and epigallocatechin gallate inhibit glucose uptake and metabolism by breast cancer cells by an estrogen receptor-independent mechanism

In this study we characterized {sup 3}H-2-deoxy-D-glucose ({sup 3}H -DG) uptake by the estrogen receptor (ER)-positive MCF7 and the ER-negative MDA-MB-231 human breast cancer cell lines and investigated the effect of quercetin (QUE) and epigallocatechin gallate (EGCG) upon {sup 3}H-DG uptake, glucose metabolism and cell viability and proliferation. In both MCF7 and MDA-MB-231 cells {sup 3}H-DG uptake was (a) time-dependent, (b) saturable with similar capacity (V{sub max}) and affinity (K{sub m}), (c) potently inhibited by cytochalasin B, an inhibitor of the facilitative glucose transporters (GLUT), (d) sodium-independent and (e) slightly insulin-stimulated. This suggests that {sup 3}H-DG uptake by both cell types is mediated by members of the GLUT family, including the insulin-responsive GLUT4 or GLUT12, while being independent of the sodium-dependent glucose transporter (SGLT1). QUE and EGCG markedly and concentration-dependently inhibited {sup 3}H-DG uptake by MCF7 and by MDA-MB-231 cells, and both compounds blocked lactate production by MCF7 cells. Additionally, a 4 h-treatment with QUE or EGCG decreased MCF7 cell viability and proliferation, an effect that was more potent when glucose was available in the extracellular medium. Our results implicate QUE and EGCG as metabolic antagonists in breast cancer cells, independently of estrogen signalling, and suggest that these flavonoids could serve as therapeutic agents/adjuvants even for ER-negative breast tumors. -- Highlights: • Glucose uptake by MCF7 and MDA-MB-231 cells is mainly mediated by GLUT1. • QUE and EGCG inhibit cellular glucose uptake thus abolishing the Warburg effect. • This process induces cytotoxicity and proliferation arrest in MCF7 cells. • The flavonoids’ effects are independent of estrogen receptor signalling.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

Sorafenib enhances proteasome inhibitor-mediated cytotoxicity via inhibition of unfolded protein response and keratin phosphorylation

Hepatocellular carcinoma (HCC) is highly resistant to conventional systemic therapies and prognosis for advanced HCC patients remains poor. Recent studies of the molecular mechanisms responsible for tumor initiation and progression have identified several potential molecular targets in HCC. Sorafenib is a multi-kinase inhibitor shown to have survival benefits in advanced HCC. It acts by inhibiting the serine/threonine kinases and the receptor type tyrosine kinases. In preclinical experiments sorafenib had anti-proliferative activity in hepatoma cells and it reduced tumor angiogenesis and increased apoptosis. Here, we demonstrate for the first time that the cytotoxic mechanisms of sorafenib include its inhibitory effects on protein ubiquitination, unfolded protein response (UPR) and keratin phosphorylation in response to endoplasmic reticulum (ER) stress. Moreover, we show that combined treatment with sorafenib and proteasome inhibitors (PIs) synergistically induced a marked increase in cell death in hepatoma- and hepatocyte-derived cells. These observations may open the way to potentially interesting treatment combinations that may augment the effect of sorafenib, possibly including drugs that promote ER stress. Because sorafenib blocked the cellular defense mechanisms against hepatotoxic injury not only in hepatoma cells but also in hepatocyte-derived cells, we must be careful to avoid severe liver injury. -- Graphical abstract: Display Omitted -- Highlights: •We examined the cytotoxic mechanisms of sorafenib in hepatoma cells. •Sorafenib induces cell death via apoptotic and necrotic fashion. •Sorafenib inhibits protein ubiquitination and unfolded protein response. •Autophagy induced by sorafenib may affect its cytotoxicity. •Sorafenib inhibits keratin phosphorylation and cytoplasmic inclusion formation.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Overexpression of FABP3 inhibits human bone marrow derived mesenchymal stem cell proliferation but enhances their survival in hypoxia

Studying the proliferative ability of human bone marrow derived mesenchymal stem cells in hypoxic conditions can help us achieve the effective regeneration of ischemic injured myocardium. Cardiac-type fatty acid binding protein (FABP3) is a specific biomarker of muscle and heart tissue injury. This protein is purported to be involved in early myocardial development, adult myocardial tissue repair and responsible for the modulation of cell growth and proliferation. We have investigated the role of FABP3 in human bone marrow derived mesenchymal stem cells under ischemic conditions. MSCs from 12 donors were cultured either in standard normoxic or modified hypoxic conditions, and the differential expression of FABP3 was tested by quantitative {sup RT}PCR and western blot. We also established stable FABP3 expression in MSCs and searched for variation in cellular proliferation and differentiation bioprocesses affected by hypoxic conditions. We identified: (1) the FABP3 differential expression pattern in the MSCs under hypoxic conditions; (2) over-expression of FABP3 inhibited the growth and proliferation of the MSCs; however, improved their survival in low oxygen environments; (3) the cell growth factors and positive cell cycle regulation genes, such as PCNA, APC, CCNB1, CCNB2 and CDC6 were all down-regulated; while the key negative cell cycle regulation genes TP53, BRCA1, CASP3 and CDKN1A were significantly up-regulated in the cells with FABP3 overexpression. Our data suggested that FABP3 was up-regulated under hypoxia; also negatively regulated the cell metabolic process and the mitotic cell cycle. Overexpression of FABP3 inhibited cell growth and proliferation via negative regulation of the cell cycle and down-regulation of cell growth factors, but enhances cell survival in hypoxic or ischemic conditions. - Highlights: • FABP3 expression pattern was studied in 12 human hypoxic-MSCs. • FABP3 mRNA and proteins are upregulated in the MSCs under hypoxic conditions. • Overexpression of FABP3 inhibits cell growth but advanced the MSC survival under hypoxia. • Overexpression of FABP3 down-regulate the cell cycle and stem cell signaling pathways.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Augmenter of liver regeneration inhibits TGF-β1-induced renal tubular epithelial-to-mesenchymal transition via suppressing TβR II expression in vitro

Tubular epithelial-to-mesenchymal transition (EMT) plays a crucial role in the progression of renal tubular interstitial fibrosis (TIF), which subsequently leads to chronic kidney disease (CKD) and eventually, end-stage renal disease (ESRD). We propose that augmenter of liver regeneration (ALR), a member of the newly discovered ALR/Erv1 protein family shown to ameliorate hepatic fibrosis, plays a similar protective role in renal tubular cells and has potential as a new treatment option for CKD. Here, we showed that recombinant human ALR (rhALR) inhibits EMT in renal tubular cells by antagonizing activation of the transforming growth factor-β1 (TGF-β1) signaling pathway. Further investigation revealed that rhALR suppresses the expression of TGF-β receptor type II (TβR II) and significantly alleviates TGF-β1-induced phosphorylation of Smad2 and nuclear factor-κB (NF-κB). No apparent adverse effects were observed upon the addition of rhALR alone to cells. These findings collectively suggest that ALR plays a role in inhibiting progression of renal tubular EMT, supporting its potential utility as an effective antifibrotic strategy to reverse TIF in CKD. - Highlights: • ALR is involved in the pathological progression of renal EMT in NRK-52E cells. • ALR suppresses the expression of TβRII and the phosphorylation of Smad2 and NF-κB. • ALR plays a role in inhibiting progression of renal tubular EMT.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

The MAPK ERK5, but not ERK1/2, inhibits the progression of monocytic phenotype to the functioning macrophage

Intracellular signaling pathways present targets for pharmacological agents with potential for treatment of neoplastic diseases, with some disease remissions already recorded. However, cellular compensatory mechanisms usually negate the initial success. For instance, attempts to interrupt aberrant signaling downstream of the frequently mutated ras by inhibiting ERK1/2 has shown only limited usefulness for cancer therapy. Here, we examined how ERK5, that overlaps the functions of ERK1/2 in cell proliferation and survival, functions in a manner distinct from ERK1/2 in human AML cells induced to differentiate by 1,25D-dihydroxyvitamin D{sub 3} (1,25D). Using inhibitors of ERK1/2 and of MEK5/ERK5 at concentrations specific for each kinase in HL60 and U937 cells, we observed that selective inhibition of the kinase activity of ERK5, but not of ERK1/2, in the presence of 1,25D resulted in macrophage-like cell morphology and enhancement of phagocytic activity. Importantly, this was associated with increased expression of the macrophage colony stimulating factor receptor (M-CSFR), but was not seen when M-CSFR expression was knocked down. Interestingly, inhibition of ERK1/2 led to activation of ERK5 in these cells. Our results support the hypothesis that ERK5 negatively regulates the expression of M-CSFR, and thus has a restraining function on macrophage differentiation. The addition of pharmacological inhibitors of ERK5 may influence trials of differentiation therapy of AML. - Highlights: • ERK5 has at least some functions in AML cells which are distinct from those of ERK1/2. • ERK5 activity negatively controls the expression of M-CSFR. • ERK5 retards the progression of differentiation from monocyte to functional macrophage.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

ERα inhibited myocardin-induced differentiation in uterine fibroids

Uterine fibroids, also known as uterine leiomyomas, are a benign tumor of the human uterus and the commonest estrogen-dependent benign tumor found in women. Myocardin is an important transcriptional regulator in smooth and cardiac muscle development. The role of myocardin and its relationship with ERα in uterine fibroids have barely been addressed. We noticed that the expression of myocardin was markedly reduced in human uterine fibroid tissue compared with corresponding normal or adjacent myometrium tissue. Here we reported that myocardin induced the transcription and expression of differentiation markers SM22α and alpha smooth muscle actin (α-SMA) in rat primary uterine smooth muscle cells (USMCs) and this effect was inhibited by ERα. Notably, we showed that, ERα induced expression of proliferation markers PCNA and ki-67 in rat primary USMCs. We also found ERα interacted with myocardin and formed complex to bind to CArG box and inhibit the SM22α promoter activity. Furthermore, ERα inhibited the transcription and expression of myocardin, and reduced the levels of transcription and expression of downstream target SM22α, a SMC differentiation marker. Our data thus provided important and novel insights into how ERα and myocardin interact to control the cell differentiation and proliferation of USMCs. Thus, it may provide potential therapeutic target for uterine fibroids.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

MiR-3202 protects smokers from chronic obstructive pulmonary disease through inhibiting FAIM2: An in vivo and in vitro study

Highlights: • Smoking decreased level of miR-3202 both in COPD patients and normal donors. • The miR-3202 influenced the release of inflammatory factors through targeting FAIM2 in T lymphocytes. • Abnormal expression of miR-3202 in T lymphocytes damaged human bronchial epithelial cells. Previous study found the variable miR-3202 as a potential biomarker in smoker with or without chronic obstructive pulmonary disease (COPD). This study aims to identify the molecular involvement of miR-3202 in the pathophysiology of COPD. Level of miR-3202 in blood sample of non-smoker non-COPD(C), smoker without COPD(S), smoker with stable COPD(S-COPD) and smoker with acute exacerbation COPD(AE-COPD) was observed by quantitative real-time PCR. By bioinformatics prediction, Fas apoptotic inhibitory molecule 2 (FAIM2) was identified as a potential target of miR-3202. In vitro, human bronchial epithelial (HBE) cells and cigarette smoke extract (CSE) stimulated T lymphocytes were co-cultured. Cell proliferation and apoptosis of HBE cells were determinated. In vivo, rats were exposed in cigarette smoke for 30 days and expression of miR-3202 and FAIM2 in bronchia were detected. Results showed that The miR-3202 was down-regulated in S, S-COPD and AE-COPD group when compared with C group. Decreased level of miR-3202 was also observed in CSE treated T lymphocyte. Additionally, CSE stimulation increased INF-γ and TNF-α levels and FAIM2 expression whereas inhibited Fas and FasL expressions in T lymphocytes. However, these effects were significantly suppressed by miR-3202 overexpression and enhanced by miR-3202 inhibitor. Likely to exogenous miR-3202, FAIM2 knockdown significantly inhibited HBE cells apoptosis, as well as inhibited INF-γ and TNF-α levels. In COPD rats model, miR-3202 was reduced while FAIM2 was up-regulated accordingly. Here, results suggest that high level miR-3202 in T lymphocytes may protect epithelial cells through targeting FAIM2. MiR-3202 might be used as a notable biomarker of COPD.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

MicroRNA-630 inhibits breast cancer progression by directly targeting BMI1

Highlights: • MiR-630 initiates apoptosis, blocks cell cycle progression and suppresses cell proliferation in breast cancer cells. • BMI1, a member of polycomb group family, is identified as a novel direct target of miR-630. • BMI1 mediates miR-630-suppressed breast cancer progression including apoptosis induction, cell cycle arrest, and proliferation inhibition. MicroRNAs (miRNAs) play critical roles in breast cancer cell biological processes, including proliferation and apoptosis by inhibiting the expression of their target genes. Herein, we reported that miR-630 overexpression initiates apoptosis, blocks cell cycle progression and suppresses cell proliferation in breast cancer cells. Furthermore, BMI1, a member of polycomb group family, was identified as a direct target of miR-630, and there was a negative correlation between the expression levels of BMI1 and miR-630 in human breast cancer samples. With a series of biology approaches, subsequently, we proved that BMI1 was a functional downstream target of miR-630 and mediated the property of miR-630-dependent inhibition of breast cancer progression. Taken together, these findings provide further evidence on the tumor-suppression function of miR-630 in breast cancer, and clarify BMI1 as a novel functional target gene of miR-630.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

NLRP3 inflammasome inhibition attenuates silica-induced epithelial to mesenchymal transition (EMT) in human bronchial epithelial cells

Highlights: • Silica challenge dramatically induced EMT in line with NLRP3 inflammasome activation in 16HBE cells. • Genetic or pharmacological inhibition of NLRP3 inflammasome attenuated silica-induced EMT. • TAK1-MAPK-Snail/NF-κB pathway was involved in NLRP3 inflammasome mediated EMT process. • Pirfenidone exerted remarkable anti-EMT effect, which might be at least partially owing to its suppression of NLRP3 inflammasome. Silicosis is an incurable and progressive lung disease characterized by chronic inflammation and fibroblasts accumulation. Studies have indicated a vital role for epithelial-mesenchymal transition (EMT) in fibroblasts accumulation. NLRP3 inflammasome is a critical mediator of inflammation in response to a wide range of stimuli (including silica particles), and plays an important role in many respiratory diseases. However, whether NLRP3 inflammasome regulates silica-induced EMT remains unknown. Our results showed that silica induced EMT in human bronchial epithelial cells (16HBE cells) in a dose- and time-dependent manner. Meanwhile, silica persistently activated NLRP3 inflammasome as indicated by continuously elevated extracellular levels of interleukin-1β (IL-1β) and IL-18. NLRP3 inflammasome inhibition by short hairpin RNA (shRNA)-mediated knockdown of NLRP3, selective inhibitor MCC950, and caspase-1 inhibitor Z-YVAD-FMK attenuated silica-induced EMT. Western blot analysis indicated that TAK1-MAPK-Snail/NF-κB pathway involved NLRP3 inflammasome-mediated EMT. Moreover, pirfenidone, a commercially and clinically available drug approved for treating idiopathic pulmonary fibrosis (IPF), effectively suppressed silica-induced EMT of 16HBE cells in line with NLRP3 inflammasome inhibition. Collectively, our results indicate that NLRP3 inflammasome is a promising target for blocking or retarding EMT-mediated fibrosis in pulmonary silicosis. On basis of this mechanism, pirfenidone might be a potential drug for the treatment of silicosis.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

E4BP4 inhibits AngII-induced apoptosis in H9c2 cardiomyoblasts by activating the PI3K-Akt pathway and promoting calcium uptake

Highlights: • E4BP4 expression in H9c2 significantly attenuates AngII-induced apoptosis. • E4BP4 inhibits AngII-induced IGF-II expression & caspase cleavage through PI3K-Akt pathway. • E4BP4 enhances calcium reuptake into SR by up-regulating p-PKA and p-PLB proteins. • E4BP4 thus acts as a survival factor in H9c2, regulating IGF-II and calcium cycling. The bZIP transcription factor E4BP4 is a survival factor that is known to be elevated in diseased heart and promote cell survival. In this study the role of E4BP4 on angiotensin-II (AngII)-induced apoptosis has been examined in in vitro cell model. H9c2 cardiomyoblast cells that overexpressed E4BP4 were exposed to AngII to observe the cardio-protective effects of E4BP4 on hypertension related apoptosis. The results from TUNEL assays revealed that E4BP4 significantly attenuated AngII-induced apoptosis. Further analysis by Western blot and RT-PCR showed that E4BP4 inhibited AngII-induced IGF-II mRNA expression and cleavage of caspase-3 through the PI3K-Akt pathway. In addition, E4BP4 enhanced calcium reuptake into the sacroplasmic reticulum by down-regulating PP2A and by up-regulating the phosphorylation of PKA and PLB proteins. Our findings indicate that E4BP4 functions as a survival factor in cardiomyoblasts by inhibiting IGF-II transcription and by regulating calcium cycling.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Ruta graveolens water extract inhibits cell-cell network formation in human umbilical endothelial cells via MEK-ERK1/2 pathway

Highlights: • RGWE inhibits HUVEC ability to form tubes on matrigel in vitro. • RGWE interferes, through MEK/ERK, with the VEGF-mediated signaling that leads to angiogenesis. • RGWE is proposed as a new therapeutic tool to prevent pathological angiogenesis. Angiogenesis is a process encompassing several steps such as endothelial cells proliferation, differentiation and migration to form a vascular network, involving different signal transduction pathways. Among these, ERK1/2 signaling mediates VEGF-dependent signaling pathway. Here we report that the water extract of Ruta graveolens (RGWE), widely known as a medicinal plant, is able to impair in a dose-dependent manner, cell network formation without affecting cell viability. Biochemical analysis showed that the major component of RGWE is rutin, unable to reproduce RGWE effect. We found that RGWE inhibits ERK1/2 phosphorylation and that this event is crucial in cell network formation since the transfection of HUVEC with a constitutively active MEK (caMEK), the ERK1/2 activator, induces a robust cell network formation as compared to untransfected and/or mock transfected cells and, more importantly, caMEK transfected cells became unresponsive to RGWE. Moreover, RGWE inhibits VEGF and nestin gene expression, necessary for vessel formation, and the caMEK transfection induces their higher expression. In conclusion, we report that RGWE is able to significantly impair vessels network formation without affecting cell viability, preventing ERK1/2 activation and, in turn, down-regulating VEGF and nestin expression. These findings point to RGWE as a potential therapeutic tool capable to interfere with pathologic angiogenesis.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Primate-specific miRNA-637 inhibited tumorigenesis in human pancreatic ductal adenocarcinoma cells by suppressing Akt1 expression

Highlights: • miR-637 acted as a tumor suppressor in pancreatic cancer. • Akt1 was a real target of miR-637 in pancreatic ductal adenocarcinoma (PDAC) cells. • Akt1 knockdown induced the cell growth inhibition and apoptosis in PDAC cells. As a primate-specific microRNA, miR-637 has been discovered for nearly 10 years. Our previous study demonstrated that miR-637 acted as a suppressor in hepatocellular carcinoma. However, its biomedical significance in pancreatic cancer remains obscure. In the present study, miR-637 was found to be significantly downregulated in pancreatic ductal adenocarcinoma (PDAC) cell lines and most of the PDAC specimens. Furthermore, the enforced overexpression of miR-637 dramatically inhibited cell proliferation and induced apoptosis of PDAC cells. Akt1, as a serine/threonine-protein kinase, has been identified as an oncogene in multiple cancers including pancreatic cancer. Our data confirmed that Akt1 was a novel target for miR-637, and its knockdown also induced cell growth inhibition and apoptosis in PDAC cells. In conclusion, our data indicated that miR-637 acted as a tumor-suppressor in PDAC, and the suppressive effect was mediated, at least partially, by suppressing Akt1 expression.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

LZ205, a newly synthesized flavonoid compound, exerts anti-inflammatory effect by inhibiting M1 macrophage polarization through regulating PI3K/AKT/mTOR signaling pathway

Highlights: • LZ205 reduced M1[HYPHEN]associated cytokines secretion without affecting M2 macrophages. • LZ205 significantly blocked expression of PI3K, p-Akt and p-mTOR in macrophages. • LZ205 significantly inhibited M1 macrophages polarization in DSS-induced colitis and alum-induced murine peritonitis. Macrophage polarization is involved in the process of inflammation. Regulation of macrophage polarization is considered to be an effective method for the treatment of various inflammatory diseases. In our study, we investigated the potential molecular mechanism of the flavonoid compound LZ205, which exhibits anti-inflammatory property. Results showed that LZ205 significantly reduced M1 macrophage-associated proinflammatory cytokines secretion by regulating PI3K/AKT/mTOR signaling pathway without affecting M2 macrophage-associated cytokines mRNA levels. In vivo studies showed that LZ205 significantly inhibited M1 macrophages polarization in DSS-induced colitis and alum-induced murine peritonitis. Consistent with in vitro studies, LZ205 significantly blocked expression of PI3K, p-AKT and p-mTOR in colon tissues and peritoneal macrophages. Taken together, LZ205 exerts anti-inflammatory effect by inhibiting M1 macrophage polarization via regulating PI3K/AKT/mTOR signaling pathway.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

6-Shogaol induces caspase-independent paraptosis in cancer cells via proteasomal inhibition

Highlights: • 6-Shogaol induced cytoplasmic vacuolation and death in breast and lung cancer cells. • Absence of caspase cleavage and DNA fragmentation proves its non-apoptotic nature. • Persistence of death in presence of autophagic inhibitors certifies it to be non-autophagic cell death. • It is found to inhibit the proteasome by binding to the β5 chymotrypsin subunit. • 6-Shogaol increases level of ER stress markers like Bip and CHOP in treated cancer cells. An α, β-unsaturated carbonyl compound of ginger, 6-Shogaol (6S), induced extensive cytoplasmic vacuolation and cell death in breast cancer cell (MDA-MB-231) and non-small lung cancer (A549) cells. In the presence of autophagic inhibitors the cells continued to exhibit cytoplasmic vacuolation and cell death clearly distinguishing it from the classic autophagic process. 6S induced death did not exhibit the characteristic apoptotic features like caspase cleavage, phosphatidyl serine exposure and DNA fragmentation. The immunofluorescence with the Endoplasmic Reticulum (ER) resident protein, calreticulin indicated that the vacuoles were of ER origin, typical of paraptosis. This was supported by the increase in level of microtubule associated protein light chain 3B (LC3 I and LC3 II) and polyubiquitin binding protein, p62. The level of ER stress markers like polyubiquitinated proteins, Bip and CHOP also consistently increased. We have found that 6S inhibits the 26S proteasome. The proteasomal inhibitory activity was elucidated by a) molecular docking of 6S onto the active site of β5 subunit and b) reduced fluorescence by the fluorogenic substrate of the chymotrypsin-like subunit. In conclusion these studies demonstrate for the first time that proteasomal inhibition by 6S induces cell death via paraptosis. So 6-shogaol may act as a template for anti-cancer lead discovery against the apoptosis resistant cancer cells.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Knockdown of MALAT1 enhances chemosensitivity of ovarian cancer cells to cisplatin through inhibiting the Notch1 signaling pathway

Highlights: • MALAT1 knockdown reversed CDDP resistance in CDDP-resistant ovarian cancer cells. • MALAT1 knockdown inhibits the Notch1 pathway and ABCC1 expression. • MALAT1 interacts with Notch1 in ovarian cancer cells. • Notch1 knockdown reverses CDDP resistance in CDDP-resistant ovarian cancer cells. • MALAT1 knockdown enhances cytotoxicity of CDDP in ovarian cancer cells in vivo. Long non-coding RNAs (lncRNAs) are critical regulators in chemoresistance of various tumors including ovarian cancer. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been reported to be upregulated and contributed to ovarian cancer tumorigenesis. The aim of this study was to explore the roles of MALAT1 and the underlying molecular regulatory mechanism in the chemoresistance of ovarian cancer cells. Our data demonstrated that MALAT1 and Notch1 mRNA were upregulated in ovarian cancer tissues, as well as cisplatin (CDDP)-resistant ovarian cancer cells. A positive correlation between MALAT1 and Notch1 mRNA expression was observed. MALAT1 knockdown significantly attenuated CDDP resistance, and enhanced CDDP-induced apoptosis in CDDP-resistant ovarian cancer cells. MALAT1 knockdown enhanced CDDP-induced apoptosis in vivo, as indicated by upregulation of Bax protein expression and downregulation of Bcl-2 protein expression. Additionally, MALAT1 knockdown inhibited the Notch1 pathway and ABCC1 expression in CDDP-resistant ovarian cancer cells. MALAT1 was demonstrated to interact with Notch1. Notch1 knockdown attenuated CDDP resistance, and downregulated the protein expression of ABCC1 in ovarian cancer cells. Taken together, our findings suggested that knockdown of MALAT-1 enhanced chemosensitivity of ovarian cancer cells to CDDP through inhibiting Notch1 signaling pathway.

60 APPLIED LIFE SCIENCES↗