Heparan sulfate proteoglycans mediate renal carcinoma metastasis

The surface proteoglycan/glycoprotein layer (glycocalyx) on tumor cells has been associated with cellular functions that can potentially enable invasion and metastasis. In addition, aggressive tumor cells with high metastatic potential have enhanced invasion rates in response to interstitial flow stimuli in vitro. Our previous studies suggest that heparan sulfate (HS) in the glycocalyx plays an important role in this flow mediated mechanostransduction and upregulation of invasive and metastatic potential. In this study, highly metastatic renal cell carcinoma cells were genetically modified to suppress HS production by knocking down its synthetic enzyme NDST1. Using modified Boyden chamber and microfluidic assays, we show that flow-enhanced invasion is suppressed in HS deficient cells. To assess the ability of these cells to metastasize in vivo, parental or knockdown cells expressing fluorescence reporters were injected into kidney capsules in SCID mice. Histological analysis confirmed that there was a large reduction (95%) in metastasis to distant organs by tumors formed from the NDST1 knockdown cells compared to control cells with intact HS. The ability of these cells to invade surrounding tissue was also impaired. The substantial inhibition of metastasis and invasion upon reduction of HS suggests an active role for the tumor cell glycocalyx in tumor progression.

[Analysis of Differentially Expressed Proteins Distribution in the Rat Brains with DAI by MALDI-TOF-IMS]

OBJECTIVES

To establish the imaging mass spectrometry for analysis of differentially expressed proteins distribution in the rat brains with diffuse axonal injury （DAI） based on matrix assisted laser desorption/ionization-time of flight imaging mass spectrometry （MALDI-TOF-IMS）.

METHODS

MALDI-TOF-IMS scanning were conducted on the brains of DAI group and control group in the m/z range of 1 000 to 20 000 using AutoflexⅢ MALDI-TOF spectrometer. ClinProTool 2.2 software was used for statistical analysis on the data of two groups, and then the differentially expressed proteins were picked out to conduct imaging. The distribution of the proteins with different m/z in the rat brains was observed.

RESULTS

Five proteins with different m/z, including 4 963, 5 634, 6 253, 6 714 and 7 532, differentially expressed in the rat brains with DAI.

CONCLUSIONS

MALDI-TOF-IMS can be used for studying the differentially expressed proteins in rat brains with DAI and the analysis method is established for exploring the distribution of differentially expressed proteins in the rat brains with DAI using imaging mass spectrometry.

Obesity-Induced Inflammation and Desmoplasia Promote Pancreatic Cancer Progression and Resistance to Chemotherapy

It remains unclear how obesity worsens treatment outcomes in patients with pancreatic ductal adenocarcinoma (PDAC). In normal pancreas, obesity promotes inflammation and fibrosis. We found in mouse models of PDAC that obesity also promotes desmoplasia associated with accelerated tumor growth and impaired delivery/efficacy of chemotherapeutics through reduced perfusion. Genetic and pharmacologic inhibition of angiotensin-II type-1 receptor reverses obesity-augmented desmoplasia and tumor growth and improves response to chemotherapy. Augmented activation of pancreatic stellate cells (PSC) in obesity is induced by tumor-associated neutrophils (TAN) recruited by adipocyte-secreted IL1β. PSCs further secrete IL1β, and inactivation of PSCs reduces IL1β expression and TAN recruitment. Furthermore, depletion of TANs, IL1β inhibition, or inactivation of PSCs prevents obesity-accelerated tumor growth. In patients with pancreatic cancer, we confirmed that obesity is associated with increased desmoplasia and reduced response to chemotherapy. We conclude that cross-talk between adipocytes, TANs, and PSCs exacerbates desmoplasia and promotes tumor progression in obesity.

SIGNIFICANCE

Considering the current obesity pandemic, unraveling the mechanisms underlying obesity-induced cancer progression is an urgent need. We found that the aggravation of desmoplasia is a key mechanism of obesity-promoted PDAC progression. Importantly, we discovered that clinically available antifibrotic/inflammatory agents can improve the treatment response of PDAC in obese hosts. Cancer Discov; 6(8); 852-69. ©2016 AACR.See related commentary by Bronte and Tortora, p. 821This article is highlighted in the In This Issue feature, p. 803.

Abstract 898: Obesity-induced inflammation and desmoplasia promote pancreatic cancer progression and resistance to chemotherapy

INTRODUCTION: With the current epidemic of obesity, the majority of pancreatic cancer patients are overweight or obese at diagnosis. Importantly, obesity worsens treatment outcomes in pancreatic cancer patients. Therefore, understanding the mechanisms that underlie the poorer prognosis of obese cancer patients is of paramount importance. Obesity causes inflammation and fibrosis in the normal pancreas due to the accumulation of dysfunctional hypertrophic adipocytes. Importantly, desmoplasia - a fibroinflammatory microenvironment - is a hallmark of pancreatic ductal adenocarcinoma (PDAC), and we have shown that activation of pancreatic stellate cells (PSCs) via angiotensin-II type 1 receptor (AT1) pathway is a major contribution to tumor desmoplasia. Whether obesity affects desmoplasia in PDACs, and interferes with delivery and response of chemotherapeutics is currently unknown.

EXPERIMENTAL DESIGN: Using both human samples and mouse models of PDAC - multiple syngeneic models of PDAC: PAN02, AK4.4, KPC, iKRAS in diet-induced and genetic obese mouse models -, we determined the effects of obesity on desmoplasia and inflammation/immune cell infiltration, tumor growth and delivery and response to chemotherapy.

RESULTS: We found that obesity aggravates desmoplasia in PDACs in both patient samples and multiple mouse models. In addition, tumors in obese mice presented with elevated levels of activated PSCs and fibrosis, as well as inflammatory cytokines and TANs,. These alterations in the tumor microenvironment in obesity associated with accelerated tumor growth, reduced tumor blood perfusion and increased hypoxia, and impaired delivery and efficacy of chemotherapeutics. Genetic ablation and pharmacological inhibition (losartan) of AT1 signaling reversed obesity-augmented desmoplasia and tumor growth, and improved the response to chemotherapy to the level observed in lean mice. We further discovered the underlying mechanisms: 1) obesity increases intra-tumor adipocytes and IL-1ß secretion by these cells; 2) increased IL-1ß induces TAN recruitment; 3) recruited TANs activate PSCs; and 4) activated PSCs enhance desmoplasia. Conversely, activated PSCs also secrete IL-1ß that recruits further TANs. Of clinical relevance, we found that metformin not only normalizes the abnormal systemic metabolism, but also reprogramms PSCs and immune cells and alleviates the fibroinflammatory microenvironment in pancreatic cancer in obesity/diabetes.. Importantly, the strategies described above were not effective in the normal weight setting.

CONCLUSION: Here we successfully demonstrated that targeting desmoplasia, including immunomodulation with anti-IL-1ß, or treatment with generic drugs such as losartan and metformin are potential strategies to potentiate treatments in PDAC patients with excess weight.

Citation Format: Joao Incio, Priya Suboj, Shan M. Chin, Chen Ivy, Mei Ng, Hadi Nia, Jelena Grahovac, Hao Liu, Shannon Kao, Suboj Babykutty, Yuhui Huang, Keehoon Jung, Nuh Rahbari, Xiaoxing Han, Vikash Chauhan, John Martin, Julia Kahn, Peigen Huang, Raquel Soares, Yves Boucher, Dai Fukumura, Rakesh Jain. Obesity-induced inflammation and desmoplasia promote pancreatic cancer progression and resistance to chemotherapy. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 898.

Implantable tissue isolation chambers for analyzing tumor dynamics in vivo

Recruitment of new blood vessels from the surrounding tissue is central to tumor progression and involves a fundamental transition of the normal, organized vasculature into a dense disarray of vessels that infiltrates the tumor. At present, studying the co-development of the tumor and recruited normal tissue is experimentally challenging because many of the important events occur rapidly and over short length scales in a dense three-dimensional space. To overcome these experimental limitations, we partially confined tumors within biocompatible and optically clear tissue isolation chambers (TICs) and implanted them in mice to create a system that is more amenable to microscopic analysis. Our goal was to integrate the tumor into a recruited host tissue - complete with vasculature - and demonstrate that the system recapitulates relevant features of the tumor microenvironment. We show that the TICs allow clear visualization of the cellular events associated with tumor growth and progression at the host-tumor interface including cell infiltration, matrix remodeling and angiogenesis. The tissue within the chamber is viable for more than a month, and the process is robust in both the skin and brain. Treatment with losartan, an angiotensin II receptor antagonist, decreased the collagen density and fiber length in the TIC, consistent with the known activity of this drug. We further show that collagen fibers display characteristic tumor signatures and play a central role in angiogenesis, guiding the migration of tethered endothelial sprouts. The methodology combines accessible methods of microfabrication with animal models and will enable more informative studies of the cellular mechanisms of tumor progression.

Molecular identification and genetic variation of varieties of Styphnolobium japonicum (Fabaceae) using SRAP markers

Thirty-four Styphnolobium japonicum varieties were analyzed using sequence-related amplified polymorphism (SRAP) markers, to investigate genetic variation and test the effectiveness of SRAP markers in DNA fingerprint establishment. Twelve primer pairs were selected from 120 primer combinations for their reproducibility and high polymorphism. We found a total of 430 amplified fragments, of which 415 fragments were considered polymorphic with an average of 34.58 polymorphic fragments for each primer combination. The percentage of polymorphic fragments was 96.60%, and four primer pairs showed 100% polymorphism. Moreover, simple matched coefficients ranged between 0.68 and 0.89, with an average of 0.785, indicating that the genetic variation among varieties was relatively low. This could be because of the narrow genetic basis of the selected breeding material. Based on the similarity coefficient value of 0.76, the varieties were divided into four major groups. In addition, abundant and clear SRAP fingerprints were obtained and could be used to establish DNA fingerprints. In the DNA fingerprints, each variety had its unique pattern that could be easily distinguished from others. The results demonstrated that 34 varieties of S. japonicum had a relatively narrow genetic variation. Hence, a broadening of the genetic basis of breeding material is necessary. We conclude that establishment of DNA fingerprint is feasible by means of SRAP markers.

Impairment of time-based prospective memory in patients with Wilson's disease

OBJECTIVE

The aim of this study was to investigate the effect of basal ganglia lesion of Wilson's disease (WD) patients on event-based prospective memory (EBPM) and time-based prospective memory (TBPM).

PATIENTS AND METHODS

A total of 30 WD patients and 30 age and education level matched healthy controls were included. EBPM (an action whenever particular words were presented) and TBPM (an action at certain times) were performed to test the involvement of the prospective memory in WD.

RESULTS

A significant difference was found in the performance of TBPM (2.9±1.1 vs. 5.8±0.4, p<0.05), but not EBPM (5.4±0.7 vs. 5.5±0.7, p>0.05) in patients with WD compared with the healthy controls.

CONCLUSIONS

Our results demonstrated that basal ganglia are involved in the prospective memory in patients with WD.

Enhanced antitumor effect of combining TRAIL and MnSOD mediated by CEA-controlled oncolytic adenovirus in lung cancer

Lung cancer, especially adenocarcinoma, is one of the leading causes of death in the world. Carcinoembryonic antigen (CEA), a superb non-small-cell lung cancer marker candidate, showed a beneficial effect in cancer therapy with oncolytic adenovirus in recent studies. Cancer-targeting dual gene-virotherapy delivers two therapeutic genes, linked by a connexon, in the replication-deficient vector instead of one gene so that they can work in common. In this study, we constructed a tumor-specific oncolytic adenovirus, CD55-TRAIL-IETD-MnSOD. The virus has the fusion protein complementary DNAs for tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and for manganese superoxide dismutase (MnSOD) complementary DNA linked through a 4-amino acid caspase-8 cleavage site (IETD), and uses a CEA promoter to control virus E1A express. This is the first work to use a CEA promoter-regulated oncolytic adenovirus carrying two therapeutic genes for cancer research. Its targeting and anticancer capacity was evaluated by in vitro and in vivo experiments. The results indicated that CD55-TRAIL-IETD-MnSOD caused more cell apoptosis than CD55-TRAIL or CD55-MnSOD alone, or their combination in vitro, with low cytotoxicity of normal cells. In the A549 tumor xenograft model in nude mice, data showed that CD55-TRAIL-IETD-MnSOD could effectively suppress tumor growth than single gene groups, with no histological damage in liver, spleen or kidney tissues. Thus, the CEA-regulated dual-gene oncolytic virus CD55-TRAIL-IETD-MnSOD may be a novel potential therapy for lung cancer.

Leptin changes differentiation fate and induces senescence in chondrogenic progenitor cells

Body weight is a component of the mechanical theory of OA (osteoarthritis) pathogenesis. Obesity was also found to be a risk factor for digital OA involving non-weight-bearing joints, which suggested that metabolism influences the occurrence and progression of OA. The metabolic origin of OA has been partially attributed to the involvement of adipokines, such as leptin, the levels of which are significantly and positively correlated with cartilage degeneration in OA patients. However, the mechanisms by which leptin-induced cartilage degeneration occurs are poorly understood. The discovery of chondrogenic progenitor cells (CPCs) opened up new opportunities for investigation. Investigating the effects of leptin on differentiation and proliferation in CPCs would increase our understanding of the roles played by leptin in the aetiology and development of OA. Here, CPCs were harvested using single-cell sorting from rat cartilage tissues to obtain mesenchymal stem-like cells, which possess clonogenicity, proliferation and stemness. High doses of leptin decreased the ability of the CPCs to migrate, inhibited their chondrogenic potential and increased their osteogenic potential, suggesting that leptin changes differentiation fates in CPCs. High doses of leptin induced cell cycle arrest and senescence in CPCs by activating the p53/p21 pathway and inhibiting the Sirt1 pathway. Inhibiting the Sirt1 pathway accelerated cartilage senescence in knockout (KO) mice. Activating the leptin pathway induced higher Ob-Rb expression and was significantly correlated with cartilage degeneration (lower levels of Coll-2) and tissue senescence (higher levels of p53/p21 and lower levels of Sirt1) in OA patients, suggesting that leptin-induced CPCs senescence contributes to the development of OA. Taken together, our results reveal new links between obesity and cartilage damage that are induced by leptin-mediated effects on cell behaviour and senescence.

Glucocorticoids impair bone formation of bone marrow stromal stem cells by reciprocally regulating microRNA-34a-5p

The inhibitory effects of glucocorticoids (GCs) on bone marrow stromal stem cell (BMSC) proliferation and osteoblastic differentiation are an important pathway through which GCs decrease bone formation. We found that microRNA-34a-5p was a critical player in dexamethasone (Dex)-inhibited BMSC proliferation and osteogenic differentiation. MicroRNA-34a-5p might be used as a therapeutic target for GC-impaired bone formation.

INTRODUCTION

The inhibitory effects of glucocorticoids (GCs) on bone marrow stromal stem cell (BMSC) proliferation and osteoblastic differentiation are an important pathway through which GCs decrease bone formation. The mechanisms of this process are still not completely understood. Recent studies implicated an important role of microRNAs in GC-mediated responses in various cellular processes, including cell proliferation and differentiation. Therefore, we hypothesized that these regulatory molecules might be implicated in the process of GC-decreased BMSC proliferation and osteoblastic differentiation.

METHODS

Western blot, quantitative real-time PCR, and cell proliferation and osteoblastic differentiation assays were employed to investigate the role of microRNAs in GC-inhibited BMSC proliferation and osteoblastic differentiation.

RESULTS

We found that microRNA-34a-5p was reciprocally regulated by Dex during the process of BMSC proliferation and osteoblastic differentiation. Furthermore, we confirmed that microRNA-34a-5p was a critical player in Dex-inhibited BMSC proliferation and osteogenic differentiation. Mechanistic studies showed that Dex inhibited BMSC proliferation by microRNA-34a-5p targeting cell cycle factors, including CDK4, CDK6, and Cyclin D1. Furthermore, downregulation of microRNA-34a-5p by Dex leads to Notch signaling activation, resulting in inhibition of BMSC osteogenic differentiation.

CONCLUSIONS

These results showed that microRNA-34a-5p, a crucial regulator for BMSC proliferation and osteogenic differentiation, might be used as a therapeutic target for GC-impaired bone formation.

Lactulose oral solution for the treatment of postpartum constipation

The purpose of this study is to explore the effectiveness and safety of lactulose oral solution in treating puerperal constipation. The lactulose group was given lactulose, 15 ml once a day, and then given a maintenance dose of 5 ~ 15 ml/time according to defecation condition of patients. Maintenance treatment lasted for one week if the symptoms were relieved; but once symptoms recurred, the medication was restored. Patients in the control group were blank controls. The treatment lasted for six weeks. The conditions of patients, adverse events and combined medication were recorded every day. Patients were evaluated with SF-36 scale before and after treatment. Two hundred and eleven patients with postpartum constipation were selected from five research institutes and they were divided into lactulose group (n=106) and control group (n=105). The curative effect and the improvement of symptoms of the lactulose group were much better than those of the control group (p less than 0.01). Constipation in the lactulose group relieved faster compared to the control group (p less than 0.05). Number of days without constipation in the lactulose group was much more than that of the control group (p less than 0.05). Defecation time in the lactulose group was shorter than that of the control group (p less than 0.05). Dose of lactulose in the lactulose group reduced week by week. Differences of general physical conditions in SF-36 scale between two groups were statistically significant (p less than 0.05). Various vital signs of the two groups had no significant changes after treatment. It can be concluded that, lactulose is an effective and safe drug for treating postpartum constipation.

Prominence of Medullary Veins on Susceptibility-Weighted Images Provides Prognostic Information in Patients with Subacute Stroke

BACKGROUND AND PURPOSE

The demonstration of prominent medullary veins in the deep white matter ipsilateral to acute ischemic stroke has been shown to predict poor clinical outcome. We have investigated the prognostic implications of prominent medullary veins in patients with subacute stroke who present outside the therapeutic window for revascularization therapy.

MATERIALS AND METHODS

Forty-three consecutive patients with ischemic stroke in the middle cerebral artery territory presenting within 3-7 days of ictus were enrolled. The presence of prominent medullary veins in the periventricular white matter of the ipsilateral and contralateral medullary vein hemispheres was recorded. Perfusion-weighted imaging was used to calculate differences in hemispheric CBF from corresponding areas. Clinical outcome was classified as good if the modified Rankin Scale score was <3.

RESULTS

Prominent medullary veins were observed in 24/43 patients with 14 ipsilateral medullary veins and 10 contralateral medullary veins. The ipsilateral medullary vein was independently associated with poor outcome (odds ratio, 11.19; P = .046). The contralateral medullary vein was not independently predictive of outcome but was significantly more common in patients with good outcome (90.0% contralateral medullary veins). A mean 64.5% decrease and a 52.4% increase of differences in hemispheric CBF were found in ipsilateral medullary veins and contralateral medullary veins, respectively.

CONCLUSIONS

The ipsilateral medullary vein was a significant predictive biomarker of poor clinical outcome after stroke and was associated with hypoperfusion. The contralateral medullary vein was associated with good clinical outcome, and we hypothesize that prominent contralateral medullary veins indirectly reflect increased CBF in the ipsilateral hemisphere due to spontaneous recanalization or collateral flow.

Epithelial Microvesicles Promote an Inflammatory Phenotype in Fibroblasts

Microvesicles (MVs) are extracellular vesicles secreted by various cell types that are involved in intercellular communication. We hypothesized that in human periodontal disease, the pocket epithelium releases MVs, which then modulate gene expression in the underlying fibroblasts to control periodontal inflammation. MVs were isolated from culture medium of gingival epithelial cells (GECs) treated with oral bacterial biofilm extract or left untreated. Biofilm treatment significantly increased MV release from the GECs. Mass spectrometry of GEC-MVs identified a total of 2,173 proteins, of which about 80% were detected in MVs from both control and biofilm-treated GECs. Among 80 signature genes of human gingival fibroblasts, 20 were significantly regulated ( P < 0.05) by MVs from control and biofilm-treated GECs in a similar manner. Matrix metalloproteinase 1 and 3 and interleukin 6 and 8 showed the strongest regulation at the mRNA and protein levels. Several cellular signaling pathways were activated by GEC-MVs in human gingival fibroblasts, including Smad and mitogen-activated protein kinase–associated pathways ERK1/2, JNK, and p38. However, ERK1/2 signaling dominated in the MV-induced gene expression changes. The results demonstrate that GEC-MVs have a strong regulatory effect on the expression of fibroblast genes associated with inflammation and matrix degradation and that bacterial biofilm stimulates the generation of GEC-MVs. This suggests that bacterial biofilms can contribute to the initiation and progression of periodontal disease by promoting a tissue-destructive phenotype in gingival fibroblasts via the enhanced secretion of epithelial MVs.

Preclinical Efficacy of Ado-trastuzumab Emtansine in the Brain Microenvironment

BACKGROUND

Central nervous system (CNS) metastases represent a major problem in the treatment of human epidermal growth factor receptor 2 (HER2)-positive breast cancer because of the disappointing efficacy of HER2-targeted therapies against brain lesions. The antibody-drug conjugate ado-trastuzumab emtansine (T-DM1) has shown efficacy in trastuzumab-resistant systemic breast cancer. Here, we tested the hypothesis that T-DM1 could overcome trastuzumab resistance in murine models of brain metastases.

METHODS

We treated female nude mice bearing BT474 or MDA-MB-361 brain metastases (n = 9-11 per group) or cancer cells grown in organotypic brain slice cultures with trastuzumab or T-DM1 at equivalent or equipotent doses. Using intravital imaging, molecular techniques and histological analysis we determined tumor growth, mouse survival, cancer cell apoptosis and proliferation, tumor drug distribution, and HER2 signaling. Data were analyzed with one-way analysis of variance (ANOVA), Kaplan-Meier analysis, and Coefficient of Determination. All statistical tests were two-sided.

RESULTS

T-DM1 delayed the growth of HER2-positive breast cancer brain metastases compared with trastuzumab. These findings were consistent between HER2-driven and PI3K-driven tumors. The activity of T-DM1 resulted in a survival benefit (median survival for BT474 tumors: 28 days for trastuzumab vs 112 days for T-DM1, hazard ratio = 6.2, 95% confidence interval = 6.1 to 85.84, P < .001). No difference in drug distribution or HER2-signaling was revealed between the two groups. However, T-DM1 led to a statistically significant increase in tumor cell apoptosis (one-way ANOVA for ApopTag, P < .001), which was associated with mitotic catastrophe.

CONCLUSIONS

T-DM1 can overcome resistance to trastuzumab therapy in HER2-driven or PI3K-driven breast cancer brain lesions due to the cytotoxicity of the DM1 component. Clinical investigation of T-DM1 for patients with CNS metastases from HER2-positive breast cancer is warranted.

[Inhibition of Sirolimus on the growth of pancreatic carcinoma and its effect on the expression of glucose transporter and hexokinase Ⅱ]

OBJECTIVE

To investigate whether Sirolimus could affect the glycolytic catabolism pathways of pancreatic carcinoma through the control of hypoxia induced factor (HIF-1α) to inhibit the growth of tumor, and explore the potential mechanism of targeting the signaling pathways of mTOR for the treatment of pancreatic carcinoma.

METHODS

Sirolimus was applied to treat the pancreatic carcinoma in nude mice orthotopic transplantation model, its difference with the control group was compared; RT-PCR and Western blot were used to measure the mRNA and protein expression of mTOR, HIF-1α, Glucose carrier protein 1 (GLUT-1) and Hexokinase Ⅱ (HK-Ⅱ), respectively; the changes of activity of HK-Ⅱ in the tumor was determined.

RESULTS

The tumor mass of the control group (1.97±0.21)g was significantly larger than that of the Sirolimus group (0.38±0.10)g (P<0.01), and the volume of the control group (1.40±0.15) mm(3) was significantly larger than that of the Sirolimus group (0.27±0.07) mm(3) (P<0.01). The expressions of mTOR, GLUT-1 and HK-Ⅱ mRNA in the control group were higher than those of the Sirolimus group (P<0.05), while no significant change was observed in the expression of HIF-1α (P>0.05); the expressions of p-mTOR, HIF-1α, GLUT-1 and HK-Ⅱ proteins in the control group were higher than those of the Sirolimus group (P<0.05). The activity of HK-Ⅱ in the control group was higher than that of the Sirolimus group (P<0.05).

CONCLUSION

Sirolimus could affect the expression of GLUT-1 and HK-Ⅱ in pancreatic carcinoma through the effects of HIF-1α to inhibit tumor growth, indicating that blocking the mTOR pathway could control the glycolytic metabolism pathways of pancreatic carcinoma, which may become the new strategy for the treatment of pancreatic carcinoma.

Pulsations with reflected boundary waves: a hydrodynamic reverse transport mechanism for perivascular drainage in the brain

Beta-amyloid accumulation within arterial walls in cerebral amyloid angiopathy is associated with the onset of Alzheimer's disease. However, the mechanism of beta-amyloid clearance along peri-arterial pathways in the brain is not well understood. In this study, we investigate a transport mechanism in the arterial basement membrane consisting of forward-propagating waves and their reflections. The arterial basement membrane is modeled as a periodically deforming annulus filled with an incompressible single-phase Newtonian fluid. A reverse flow, which has been suggested in literature as a beta-amyloid clearance pathway, can be induced by the motion of reflected boundary waves along the annular walls. The wave amplitude and the volume of the annular region govern the flow magnitude and may have important implications for an aging brain. Magnitudes of transport obtained from control volume analysis and numerical solutions of the Navier-Stokes equations are presented.

Sivelestat sodium hydrate attenuates acute lung injury by decreasing systemic inflammation in a rat model of severe burns

OBJECTIVE

Patients with severe burns often develop acute lung injury (ALI), systemic inflammatory response syndrome (SIRS) often complicates with ALI. Sivelestat sodium hydrate is an effective drug against ALI. However, the mechanisms of this beneficial effect are still poorly understood. In the current study, we evaluate the effects of sivelestat sodium hydrate on systemic and local inflammatory parameters (neutrophil elastase [NE], interleukin [IL]-8, matrix metalloproteinase [MMP] 2 and 9) in a rat model of severe burns and ALI. And to analyze the correlations between expression of NE and IL-8 and acute lung injury.

MATERIALS AND METHODS

48 Sprague-Dawley (SD) rats were divided into 3 groups: normal control group, severe burns injury group and severe burns treated with sivelestat sodium hydrate group (SSI). The lung water content and PaO2 were detected in each group. Pathological manifestations in each group were observed for pathology scoring in SD rats with acute lung injury. ELISA was used for detecting expression of NE and IL-8 in serum and BAL specimens of SD rats in each group. RT-PCR was used to detect mRNA expression of NE and IL-8 in lung tissues of each group. Western blotting was used for detecting protein expression of MMP-2 and MMP-9 in lung tissues of each group. SPSS 18.0 was used for statistical analysis.

RESULTS

The PaO2 was significantly increased after sivelestat sodium hydrate intravenous injection. Pathological score and water content of lung tissue were significantly decreased in SSI group compared with severe burns injury group, slightly higher than that normal control group. NE and IL-8 levels significantly decreased in serum, BAL and lung tissue specimens after sivelestat sodium hydrate intravenous injection; Expression of MMP-2 and MMP-9 were significantly up-regulated in severe burns group and showed no significantly changed after sivelestat sodium hydrate intravenous injection.

CONCLUSIONS

In a rat model of severe burns and ALI, administration of sivelestat sodium hydrate improved symptoms of ALI and significantly decreased inflammatory parameters NE and IL-8.

Characterization of OsPM19L1 encoding an AWPM-19-like family protein that is dramatically induced by osmotic stress in rice

The plant-specific AWPM-19-domain proteins play important roles in plant development and stress responses. In the current study, OsPM19L1 encoding Oryza sativa AWPM-19-like protein 1 was isolated from rice. Tissue-specific gene expression analysis revealed that OsPM19L1 was highly expressed in the leaf sheath of rice. Interestingly, expression of OsPM19L1 was high at the early stage of panicle development and decreased thereafter. qRT-PCR analysis indicated that OsPM19L1 was dramatically induced by 20% PEG stress (>600-fold), exogenous abscisic acid (>350-fold), salt and cold stress. Subcellular localization assay suggested that the OsPM19L1-GFP (green fluorescent protein) fusion protein was localized in the membrane system in rice cells. Moreover, under stress conditions, OsPM19L1 expression was enhanced in an ABI5-Like1 (ABL1) deficiency rice mutant, abl1, suggesting that ABL1 negatively regulates OsPM19L1 gene expression. Thus, OsPM19L1 appears to be closely associated with stress tolerance through ABA-dependent pathway in rice.

Antibacterial and photochemical properties of cellulose nanofiber-titania nanocomposites loaded with two different types of antibiotic medicines

Nanocomposite dermal drug delivery systems based on cellulose nanofibers with grafted titania nanoparticles loaded by two antibiotic medicines from different classes, i.e. tetracycline (TC) and phosphomycin (Phos), were successfully produced by a "green chemistry" approach in aqueous media. The influence of a different surface binding mechanism between the drug molecule and modified cellulose nanofibers on the release of the drug and, as a result, on antimicrobial properties against common pathogens Gram-positive, Staphylococcus aureus and Gram-negative Escherichia coli was investigated. The disk diffusion method and broth culture tests using varying concentrations of drugs loaded to nanocomposites were carried out to investigate the antibacterial effects. The influence of UV irradiation on the stability of the obtained nanocomposites and their antibacterial properties after irradiation were also investigated, showing enhanced stability especially for the TC loaded materials. These findings suggest that the obtained nanocomposites are promising materials for the development of potentially useful antimicrobial patches.

OsMYB511 encodes a MYB domain transcription activator early regulated by abiotic stress in rice

The MYB-domain proteins exist universally across diverse organisms and regulate numerous processes during the plant life cycle. In the present research, a full-length MYB gene OsMYB511 was identified from rice seedlings through microarray data. Induction of OsMYB511 by cold stress was dramatic in japonica cultivar Jiucaiqing as compared to indica IR26. In addition to cold, OsMYB511 was also markedly induced by osmotic stress, high temperature, and exogenous ABA, suggesting that OsMYB511 is a multiple-stress responsive gene in rice. Tissue-specific expression analysis indicated that OsMYB511 was highly expressed in rice panicles at earlier development stage. Interestingly, OsMYB511 expression is fully subjected to circadian rhythm regulation. The subcellular localization and yeast hybrid assay suggested that OsMYB511 is nucleus-localized transcription activator. Deletion analysis suggested that trans-activation activity of OsMYB511 relied on its C-terminus. Co-expression analysis revealed additional 2 MYB genes co-expressed with OsMYB511, implying that these MYB genes might coordinately regulate stress responses in rice.

A learnable parallel processing architecture towards unity of memory and computing

Developing energy-efficient parallel information processing systems beyond von Neumann architecture is a long-standing goal of modern information technologies. The widely used von Neumann computer architecture separates memory and computing units, which leads to energy-hungry data movement when computers work. In order to meet the need of efficient information processing for the data-driven applications such as big data and Internet of Things, an energy-efficient processing architecture beyond von Neumann is critical for the information society. Here we show a non-von Neumann architecture built of resistive switching (RS) devices named "iMemComp", where memory and logic are unified with single-type devices. Leveraging nonvolatile nature and structural parallelism of crossbar RS arrays, we have equipped "iMemComp" with capabilities of computing in parallel and learning user-defined logic functions for large-scale information processing tasks. Such architecture eliminates the energy-hungry data movement in von Neumann computers. Compared with contemporary silicon technology, adder circuits based on "iMemComp" can improve the speed by 76.8% and the power dissipation by 60.3%, together with a 700 times aggressive reduction in the circuit area.

An orthotopic mouse model of hepatocellular carcinoma with underlying liver cirrhosis

Subcutaneous xenografts have been used for decades to study hepatocellular carcinoma (HCC). These models do not reproduce the specific pathophysiological features of HCCs, which occur in cirrhotic livers that show pronounced necroinflammation, abnormal angiogenesis and extensive fibrosis. As these features are crucial for studying the role of the pathologic host microenvironment in tumor initiation, progression and treatment response, alternative HCC models are desirable. Here we describe a syngeneic orthotopic HCC model in immunocompetent mice with liver cirrhosis induced by carbon tetrachloride (CCl4) that recapitulates key features of human HCC. Induction of substantial hepatic fibrosis requires 12 weeks of CCl4 administration. Intrahepatic implantation of mouse HCC cell lines requires 30 min per mouse. Tumor growth varies by tumor cell line and mouse strain used. Alternatively, tumors can be induced in a genetically engineered mouse model. In this setting, CCl4 is administered for 12 weeks after tail-vein injection of Cre-expressing adenovirus (adeno-Cre) in Stk4(-/-)Stk3(F/-) (also known as Mst1(-/-)Mst2(F/-); F indicates a floxed allele) mice, and it results in the development of HCC tumors (hepatocarcinogenesis) concomitantly with liver cirrhosis.

CXCR4 inhibition in tumor microenvironment facilitates anti-programmed death receptor-1 immunotherapy in sorafenib-treated hepatocellular carcinoma in mice

Sorafenib, a broad tyrosine kinase inhibitor, is the only approved systemic therapy for advanced hepatocellular carcinoma (HCC) but provides limited survival benefits. Recently, immunotherapy has emerged as a promising treatment strategy, but its role remains unclear in HCCs, which are associated with decreased cytotoxic CD8(+) T-lymphocyte infiltration in both murine and human tumors. Moreover, in mouse models after sorafenib treatment intratumoral hypoxia is increased and may fuel evasive resistance. Using orthotopic HCC models, we now show that increased hypoxia after sorafenib treatment promotes immunosuppression, characterized by increased intratumoral expression of the immune checkpoint inhibitor programmed death ligand-1 and accumulation of T-regulatory cells and M2-type macrophages. We also show that the recruitment of immunosuppressive cells is mediated in part by hypoxia-induced up-regulation of stromal cell-derived 1 alpha. Inhibition of the stromal cell-derived 1 alpha receptor (C-X-C receptor type 4 or CXCR4) using AMD3100 prevented the polarization toward an immunosuppressive microenvironment after sorafenib treatment, inhibited tumor growth, reduced lung metastasis, and improved survival. However, the combination of AMD3100 and sorafenib did not significantly change cytotoxic CD8(+) T-lymphocyte infiltration into HCC tumors and did not modify their activation status. In separate experiments, antibody blockade of the programmed death ligand-1 receptor programmed death receptor-1 (PD-1) showed antitumor effects in treatment-naive tumors in orthotopic (grafted and genetically engineered) models of HCC. However, anti-PD-1 antibody treatment had additional antitumor activity only when combined with sorafenib and AMD3100 and not when combined with sorafenib alone.

CONCLUSION

Anti-PD-1 treatment can boost antitumor immune responses in HCC models; when used in combination with sorafenib, anti-PD-1 immunotherapy shows efficacy only with concomitant targeting of the hypoxic and immunosuppressive microenvironment with agents such as CXCR4 inhibitors.

Galangin-induced down-regulation of BACE1 by epigenetic mechanisms in SH-SY5Y cells

Alzheimer's disease (AD), the most common cause of dementia in aging people, is found to have a critical link with the deposition of β-amyloid (Aβ) in the brain. The inhibition of β-site amyloid precursor protein-cleaving enzyme 1 (BACE1), a key enzyme for Aβ production, is a promising target for AD therapy. In pursuit to find a potent inhibitor of BACE1, we identified galangin, a natural flavonoid, had a significant lowering effect on Aβ levels. Furthermore, a dramatic reduction of BACE1 at mRNA and protein levels was observed after galangin treatment. We further investigated whether epigenetic mechanisms, such as histone acetylation and DNA methylation, were involved in galangin-induced transcriptional regulation of BACE1. Our data show that galangin induces a decrease of acetylated H3 in the BACE1 promoter regions through the up-regulation of endogenous HDAC1-mediated deacetylation, which is independent of DNA methylation status. The above findings suggest a novel mechanism for polyphenols' neuroprotective effect in neurodegeneration and galangin as a potential drug candidate for AD therapy.

Extension of the Peters-Belson method to estimate health disparities among multiple groups using logistic regression with survey data

Determining the extent of a disparity, if any, between groups of people, for example, race or gender, is of interest in many fields, including public health for medical treatment and prevention of disease. An observed difference in the mean outcome between an advantaged group (AG) and disadvantaged group (DG) can be due to differences in the distribution of relevant covariates. The Peters-Belson (PB) method fits a regression model with covariates to the AG to predict, for each DG member, their outcome measure as if they had been from the AG. The difference between the mean predicted and the mean observed outcomes of DG members is the (unexplained) disparity of interest. We focus on applying the PB method to estimate the disparity based on binary/multinomial/proportional odds logistic regression models using data collected from complex surveys with more than one DG. Estimators of the unexplained disparity, an analytic variance-covariance estimator that is based on the Taylor linearization variance-covariance estimation method, as well as a Wald test for testing a joint null hypothesis of zero for unexplained disparities between two or more minority groups and a majority group, are provided. Simulation studies with data selected from simple random sampling and cluster sampling, as well as the analyses of disparity in body mass index in the National Health and Nutrition Examination Survey 1999-2004, are conducted.  Empirical results indicate that the Taylor linearization variance-covariance estimation is accurate and that the proposed Wald test maintains the nominal level.

Determinates of tumor response to radiation: tumor cells, tumor stroma and permanent local control

BACKGROUND AND PURPOSE

The causes of tumor response variation to radiation remain obscure, thus hampering the development of predictive assays and strategies to decrease resistance. The present study evaluates the impact of host tumor stromal elements and the in vivo environment on tumor cell kill, and relationship between tumor cell radiosensitivity and the tumor control dose.

MATERIAL AND METHODS

Five endpoints were evaluated and compared in a radiosensitive DNA double-strand break repair-defective (DNA-PKcs(-/-)) tumor line, and its DNA-PKcs repair competent transfected counterpart. In vitro colony formation assays were performed on in vitro cultured cells, on cells obtained directly from tumors, and on cells irradiated in situ. Permanent local control was assessed by the TCD50 assay. Vascular effects were evaluated by functional vascular density assays.

RESULTS

The fraction of repair competent and repair deficient tumor cells surviving radiation did not substantially differ whether irradiated in vitro, i.e., in the absence of host stromal elements and factors, from the fraction of cells killed following in vivo irradiation. Additionally, the altered tumor cell sensitivity resulted in a proportional change in the dose required to achieve permanent local control. The estimated number of tumor cells per tumor, their cloning efficiency and radiosensitivity, all assessed by in vitro assays, were used to predict successfully, the measured tumor control doses.

CONCLUSION

The number of clonogens per tumor and their radiosensitivity govern the permanent local control dose.

KCNQ/Kv7 channel activator flupirtine protects against acute stress-induced impairments of spatial memory retrieval and hippocampal LTP in rats

Spatial memory retrieval and hippocampal long-term potentiation (LTP) are impaired by stress. KCNQ/Kv7 channels are closely associated with memory and the KCNQ/Kv7 channel activator flupirtine represents neuroprotective effects. This study aims to test whether KCNQ/Kv7 channel activation prevents acute stress-induced impairments of spatial memory retrieval and hippocampal LTP. Rats were placed on an elevated platform in the middle of a bright room for 30 min to evoke acute stress. The expression of KCNQ/Kv7 subunits was analyzed at 1, 3 and 12 h after stress by Western blotting. Spatial memory was examined by the Morris water maze (MWM) and the field excitatory postsynaptic potential (fEPSP) in the hippocampal CA1 area was recorded in vivo. Acute stress transiently decreased the expression of KCNQ2 and KCNQ3 in the hippocampus. Acute stress impaired the spatial memory retrieval and hippocampal LTP, the KCNQ/Kv7 channel activator flupirtine prevented the impairments, and the protective effects of flupirtine were blocked by XE-991 (10,10-bis(4-Pyridinylmethyl)-9(10H)-anthracenone), a selective KCNQ channel blocker. Furthermore, acute stress decreased the phosphorylation of glycogen synthase kinase-3β (GSK-3β) at Ser9 in the hippocampus, and flupirtine inhibited the reduction. These results suggest that the KCNQ/Kv7 channels may be a potential target for protecting both hippocampal synaptic plasticity and spatial memory retrieval from acute stress influences.

Electric-field-induced Skyrmion distortion and giant lattice rotation in the magnetoelectric insulator Cu2OSeO3

Uniquely in Cu2OSeO3, the Skyrmions, which are topologically protected magnetic spin vortexlike objects, display a magnetoelectric coupling and can be manipulated by externally applied electric (E) fields. Here, we explore the E-field coupling to the magnetoelectric Skyrmion lattice phase, and study the response using neutron scattering. Giant E-field induced rotations of the Skyrmion lattice are achieved that span a range of ∼25°. Supporting calculations show that an E-field-induced Skyrmion distortion lies behind the lattice rotation. Overall, we present a new approach to Skyrmion control that makes no use of spin-transfer torques due to currents of either electrons or magnons.

Lifetime increased cancer risk in mice following exposure to clinical proton beam-generated neutrons

PURPOSE

To evaluate the life span and risk of cancer following whole-body exposure of mice to neutrons generated by a passively scattered clinical spread-out Bragg peak (SOBP) proton beam.

METHODS AND MATERIALS

Three hundred young adult female FVB/N mice, 152 test and 148 control, were entered into the experiment. Mice were placed in an annular cassette around a cylindrical phantom, which was positioned lateral to the mid-SOBP of a 165-MeV, clinical proton beam. The average distance from the edge of the mid-SOBP to the conscious active mice was 21.5 cm. The phantom was irradiated with once-daily fractions of 25 Gy, 4 days per week, for 6 weeks. The age at death and cause of death (ie, cancer and type vs noncancer causes) were assessed over the life span of the mice.

RESULTS

Exposure of mice to a dose of 600 Gy of proton beam-generated neutrons, reduced the median life span of the mice by 4.2% (Kaplan-Meier cumulative survival, P=.053). The relative risk of death from cancer in neutron exposed versus control mice was 1.40 for cancer of all types (P=.0006) and 1.22 for solid cancers (P=.09). For a typical 60 Gy dose of clinical protons, the observed 22% increased risk of solid cancer would be expected to decrease by a factor of 10.

CONCLUSIONS

Exposure of mice to neutrons generated by a proton dose that exceeds a typical course of radiation therapy by a factor of 10, resulted in a statistically significant increase in the background incidence of leukemia and a marginally significant increase in solid cancer. The results indicate that the risk of out-of-field second solid cancers from SOBP proton-generated neutrons and typical treatment schedules, is 6 to 10 times less than is suggested by current neutron risk estimates.

Expression analysis of differentially expressed miRNAs in male and female chicken embryos

MicroRNAs (miRNAs) are small non-coding RNA molecules that play key roles in the regulation of development processes of many tissues and organs at the post-transcriptional level. However, little is known about how they affect chicken gonadal development. We examined the expression of four miRNAs (miR-218, -200b, -196, and -206) in chicken embryonic gonads at embryonic days 3.5-6.5. Their target genes were predicted by miRDB, TargetScan and PicTar algorithms. The expression levels of these four miRNAs differed with sex to varying degrees; miR-200b was expressed at a significantly higher level in female gonads during the entire interval. The whole mount in situ hybridization result showed considerably higher expression of miR-200b in females than in males in E5.5 embryos. The miRNA target scanning results indicated several genes with functions in gonad development and gonad function. We conclude that miR-200b is involved in the regulation of gonad development and sexual differentiation of chicken embryos.

Differential effects of sorafenib on liver versus tumor fibrosis mediated by stromal-derived factor 1 alpha/C-X-C receptor type 4 axis and myeloid differentiation antigen-positive myeloid cell infiltration in mice

Sorafenib--a broad kinase inhibitor--is a standard therapy for advanced hepatocellular carcinoma (HCC) and has been shown to exert antifibrotic effects in liver cirrhosis, a precursor of HCC. However, the effects of sorafenib on tumor desmoplasia--and its consequences on treatment resistance--remain unknown. We demonstrate that sorafenib has differential effects on tumor fibrosis versus liver fibrosis in orthotopic models of HCC in mice. Sorafenib intensifies tumor hypoxia, which increases stromal-derived factor 1 alpha (SDF-1α) expression in cancer and stromal cells and, subsequently, myeloid differentiation antigen-positive (Gr-1(+)) myeloid cell infiltration. The SDF-1α/C-X-C receptor type 4 (CXCR4) pathway directly promotes hepatic stellate cell (HSC) differentiation and activation through the mitogen-activated protein kinase pathway. This is consistent with the association between SDF-1α expression with fibrotic septa in cirrhotic liver tissues as well as with desmoplastic regions of human HCC samples. We demonstrate that after treatment with sorafenib, SDF-1α increased the survival of HSCs and their alpha-smooth muscle actin and collagen I expression, thus increasing tumor fibrosis. Finally, we show that Gr-1(+) myeloid cells mediate HSC differentiation and activation in a paracrine manner. CXCR4 inhibition, using AMD3100 in combination with sorafenib treatment, prevents the increase in tumor fibrosis--despite persistently elevated hypoxia--in part by reducing Gr-1(+) myeloid cell infiltration and inhibits HCC growth. Similarly, antibody blockade of Gr-1 reduces tumor fibrosis and inhibits HCC growth when combined with sorafenib treatment.

CONCLUSION

Blocking SDF-1α/CXCR4 or Gr-1(+) myeloid cell infiltration may reduce hypoxia-mediated HCC desmoplasia and increase the efficacy of sorafenib treatment.

Poly(3-hexylthiophene) nanostructured materials for organic electronics applications

Semiconducting polymers have been developed during the last few decades and are currently used in various organic electronics applications. Regioregular poly(3-hexylthiophene) (P3HT) is the most employed semiconducting polymer for organic electronics applications. The development of living Grignard metathesis polymerization (GRIM) allowed the synthesis of P3HT with well-defined molecular weights and functional end groups. A large number of block copolymers containing P3HT have been reported, and their opto-electronic properties have been investigated. The performance of P3HT homopolymer and block copolymers in field-effect transistors and bulk heterojunction solar cells are discussed in this review. The morphology of the P3HT materials is also discussed.