High Concentration of Glial Cell Line-Derived Neurotrophic Factor Protects Primary Astrocytes from Apoptosis

Background: Studies have shown that astrocytes play an important role in a variety of biological processes, so damage to astrocytes can cause a series of related diseases. Glial cell line-derived neurotrophic factor (GDNF) has always been considered a protective factor for dopamine neurons. However, it remains unclear whether GDNF has a protective effect on glial cells, especially astrocytes. In this study, we put forward the hypothesis that a high concentration of GDNF in the microenvironment of astrocytes exerts an inhibitory effect on the apoptosis of astrocytes by DNA-damaging reagents. Methods: We isolated, purified, and identified primary astrocytes from neonate rats. Astrocytes were exposed to mitoxantrone (MTN, a DNA-damaging compound) for 24 h. The effects of MTN on astrocytes were tested by Hoechst 33342 staining, CCK-8 assay, and flow cytometry assay. One of the concentrations of MTN was applied to construct an apoptotic model of astrocytes. The astrocytes were then treated with GDNF together with a selected concentration of MTN for 24 h. The cell viability, cell nucleus morphology, and apoptosis ratio of the cells was assessed by Hoechst 33342 staining, CCK-8 assay, and flow cytometry assay, respectively. RNA sequencing (RNA-Seq), quantitative PCR analysis, and KEGG pathway mapping were performed to examine the genes involved in the procedure. Finally, Western blot analysis was applied to confirm the expression levels of the proteins of interest. Results: Hoechst 33342 staining revealed a one-tenth change in the percentage of Hoechst-positive cells after the addition of 500 ng/mL GDNF combined with 1,000 nM MTN for 24 h. The viability of the cells treated the same as described above was 1.4-fold that of the control group. Flow cytometry assays indicated that the apoptotic rates were 17.67, 8.67, and 4.34% for 0, 200, and 500 ng/mL GDNF, respectively. Birc2, Birc3, and Gadd45b were linked to the antiapoptotic process induced by GDNF in astrocytes. Western blot analysis confirmed the elevated expression of Birc2 and Gadd45b. Conclusions: Our studies revealed that GDNF has a noticeable antiapoptotic effect on gene-injured astrocytes. This may provide critical clues for the treatment of a series of diseases in which damaged astrocytes are involved.

Developing Multipollutant Exposure Indicators of Traffic Pollution: The Dorm Room Inhalation to Vehicle Emissions (DRIVE) Study

Introduction

The Dorm Room Inhalation to Vehicle Emissions (DRIVE2) study was conducted to measure traditional single-pollutant and novel multipollutant traffic indicators along a complete emission-to-exposure pathway. The overarching goal of the study was to evaluate the suitability of these indicators for use as primary traffic exposure metrics in panel-based and small-cohort epidemiological studies.

Methods

Intensive field sampling was conducted on the campus of the Georgia Institute of Technology (GIT) between September 2014 and January 2015 at 8 monitoring sites (2 indoors and 6 outdoors) ranging from 5 m to 2.3 km from the busiest and most congested highway artery in Atlanta. In addition, 54 GIT students living in one of two dormitories either near (20 m) or far (1.4 km) from the highway were recruited to conduct personal exposure sampling and weekly biomonitoring. The pollutants measured were selected to provide information about the heterogeneous particulate and gaseous composition of primary traffic emissions, including the traditional traffic-related species (e.g., carbon monoxide [CO], nitrogen dioxide [NO2], nitric oxide [NO], fine particulate matter [PM2.5], and black carbon [BC]), and of secondary species (e.g., ozone [O3] and sulfate as well as organic carbon [OC], which is both primary and secondary) from traffic and other sources. Along with these pollutants, we also measured two multipollutant traffic indicators: integrated mobile source indicators (IMSIs) and fine particulate matter oxidative potential (FPMOP). IMSIs are derived from elemental carbon (EC), CO, and nitrogen oxide (NOx) concentrations, along with the fractions of these species emitted by gasoline and diesel vehicles, to construct integrated estimates of gasoline and diesel vehicle impacts. Our FPMOP indicator was based on an acellular assay involving the depletion of dithiothreitol (DTT), considering both water-soluble and insoluble components (referred to as FPMOPtotal-DTT). In addition, a limited assessment of 18 low-cost sensors was added to the study to supplement the four original aims.

Results

Pollutant levels measured during the study showed a low impact by this highway hotspot source on its surrounding vicinity. These findings are broadly consistent with results from other studies throughout North America showing decreased relative contributions to urban air pollution from primary traffic emissions. We view these reductions as an indication of a changing near-road environment, facilitated by the effectiveness of mobile source emission controls. Many of the primary pollutant species, including NO, CO, and BC, decreased to near background levels by 20 to 30 m from the highway source. Patterns of correlation among the sites also varied by pollutant and time of day. NO2 exhibited spatial trends that differed from those of the other single-pollutant primary traffic indicators. We believe this was caused by kinetic limitations in the photochemical chemistry, associated with primary emission reductions, required to convert the NO-dominant primary NOx, emitted from automobiles, to NO2. This finding provides some indication of limitations in the use of NO2 as a primary traffic exposure indicator in panel-based health effect studies. Roadside monitoring of NO, CO, and BC tended to be more strongly correlated with sites, both near and far from the road, during morning rush hour periods and often weakly to moderately correlated during other time periods of the day. This pattern was likely associated with diurnal changes in mixing and chemistry and their impact on spatial heterogeneity across the campus. Among our candidate multipollutant primary traffic indicators, we report several key findings related to the use of oxidative potential (OP)-based indicators. Although earlier studies have reported elevated levels of FPMOP in direct exhaust emissions, we found that atmospheric processing further enhanced FPMOPtotal-DTT, likely associated with the oxidation of primary polycyclic aromatic hydrocarbons (PAHs) to quinones and hydroxyquinones and with the oxidization and water solubility of metals. This has important implications in terms both of the utility of FPMOPtotal-DTT as a marker for exhaust emissions and of the importance of atmospheric processing of particulate matter (PM) being tied to potential health outcomes. The results from the personal exposure monitoring also point to the complexity and diversity of the spatiotemporal variability patterns among the study monitoring sites and the importance of accounting for location and spatial mobility when estimating exposures in panel-based and small-cohort studies. This was most clearly demonstrated with the personal BC measurements, where ambient roadside monitoring was shown to be a poor surrogate for exposures to BC. Alternative surrogates, including ambient and indoor BC at the participants' respective dorms, were more strongly associated with personal BC, and knowledge of the participants' mean proximity to the highway was also shown to explain a substantial level of the variability in corresponding personal exposures to both BC and NO2. In addition, untargeted metabolomic indicators measured in plasma and saliva, which represent emerging methods for measuring exposure, were used to extract approximately 20,000 and 30,000 features from plasma and saliva, respectively. Using hydrophilic interaction liquid chromatography (HILIC) in the positive ion mode, we identified 221 plasma features that differed significantly between the two dorm cohorts. The bimodal distribution of these features in the HILIC column was highly idiosyncratic; one peak consisted of features with elevated intensities for participants living in the near dorm; the other consisted of features with elevated intensities for participants in the far dorm. Both peaks were characterized by relatively short retention times, indicative of the hydrophobicity of the identified features. The results from the metabolomics analyses provide a strong basis for continuing this work toward specific chemical validation of putative biomarkers of traffic-related pollution. Finally, the study had a supplemental aim of examining the performance of 18 low-cost CO, NO, NO2, O3, and PM2.5 pollutant sensors. These were colocated alongside the other study monitors and assessed for their ability to capture temporal trends observed by the reference monitoring instrumentation. Generally, we found the performance of the low-cost gas-phase sensors to be promising after extensive calibration; the uncalibrated measurements alone, however, would likely not have led to reliable results. The low-cost PM sensors we evaluated had poor accuracy, although PM sensor technology is evolving quickly and warrants future attention.

Conclusions

An immediate implication of the changing near-road environment is that future studies aimed at characterizing hotspots related to mobile sources and their impacts on health will need to consider multiple approaches for characterizing spatial gradients and exposures. Specifically and most directly, the mobile source contributions to ambient concentrations of single-pollutant indicators of traffic exposure are not as distinguishable to the degree that they have been in the past. Collectively, the study suggests that characterizing exposures to traffic-related pollutants, which is already difficult, will become more difficult because of the reduction in traffic-related emissions. Additional multi-tiered approaches should be considered along with traditional measurements, including the use of alternative OP measures beyond those based on DTT assays, metabolomics, low-cost sensors, and air quality modeling.

Analysis of Long Noncoding RNA and mRNA Expression Profiles in IL-9-Activated Astrocytes and EAE Mice

BACKGROUND/AIMS

Multiple sclerosis (MS) is an autoimmune disease in the central nervous system associated with demyelination and axonal injury. Astrocyte activation is involved in the pathogenesis of MS and experimental autoimmune encephalomyelitis (EAE), an animal model of MS. This study was designed to find potential lncRNAs in EAE mice and activated astrocytes.

METHODS

we performed microarray analysis of lncRNAs from the brain tissues of EAE mice and primary mouse astrocytes treated with IL-9(50 ng/ml). 12 lncRNAs were validated through real-time PCR. Gene ontology and KEGG pathway analysis were applied to explore the potential functions of lncRNAs.

RESULTS

Differentially expressed 3300 lncRNAs and 3250 mRNAs were in the brain tissues of EAE mice, and 3748 lncRNAs and 3332 mRNAs were in activated astrocytes. Notably, there were 2 co-up-regulated lncRNAs and 3 co-down-regulated lncRNAs both in the brain tissues of EAE mice and in activated astrocytes, including Gm14005, Gm12478, mouselincRNA1117, AK080435, and mouselincRNA0681, which regulate the ER calcium flux kinetics, zinc finger protein and cell apoptosis. Similarly, there were 7 mRNAs co-up-regulated and 2 mRNAs co-down-regulated both in vivo and in vitro. Gene ontology and KEGG pathway analysis showed that the biological functions of differentially expressed mRNAs were associated with metabolism, development and inflammation. The results of realtime PCR validation were consistent with the data from the microarrays.

CONCLUSIONS

Our data uncovered the expression profiles of lncRNAs and mRNAs in vivo and in vitro, which may help delineate the mechanisms of astrocyte activation during MS/EAE process.

An in-situ thermally regenerated air purifier for indoor formaldehyde removal

Formaldehyde is a common indoor pollutant that is an irritant and has been classified as carcinogen to humans. Adsorption technology is safe and stable and removes formaldehyde efficiently, but its short life span and low adsorption capacity limit its indoor application. To overcome these limitations, we propose an in-situ thermally regenerated air purifier (TRAP) which self-regenerates as needed. This purifier has four working modes: cleaning mode, regeneration mode, exhaust mode, and outdoor air in-take mode, all of which are operated by valve switching. We developed a real-scale TRAP prototype with activated carbon as adsorbent. The experimental testing showed that the regeneration ratios for formaldehyde of TRAP were greater than 90% during 5 cycles of adsorption-regeneration and that through the 5 cycles, there was no damage to the adsorption material as confirmed by scanning electron microscope (SEM) and Brunauer-Emmett-Teller (BET) tests. The total energy consumption by the prototype for purifying 1000 m³ indoor air was 0.26 kWh. This in-situ thermal-regeneration method can recover the purifier's adsorption ability through at least five cycles.

Comparative genomic analysis of the Lipase3 gene family in five plant species reveals distinct evolutionary origins

Lipases are physiologically important and ubiquitous enzymes that share a conserved domain and are classified into eight different families based on their amino acid sequences and fundamental biological properties. The Lipase3 family of lipases was reported to possess a canonical fold typical of α/β hydrolases and a typical catalytic triad, suggesting a distinct evolutionary origin for this family. Genes in the Lipase3 family do not have the same functions, but maintain the conserved Lipase3 domain. There have been extensive studies of Lipase3 structures and functions, but little is known about their evolutionary histories. In this study, all lipases within five plant species were identified, and their phylogenetic relationships and genetic properties were analyzed and used to group them into distinct evolutionary families. Each identified lipase family contained at least one dicot and monocot Lipase3 protein, indicating that the gene family was established before the split of dicots and monocots. Similar intron/exon numbers and predicted protein sequence lengths were found within individual groups. Twenty-four tandem Lipase3 gene duplications were identified, implying that the distinctive function of Lipase3 genes appears to be a consequence of translocation and neofunctionalization after gene duplication. The functional genes EDS1, PAD4, and SAG101 that are reportedly involved in pathogen response were all located in the same group. The nucleotide diversity (Dxy) and the ratio of nonsynonymous to synonymous nucleotide substitutions rates (Ka/Ks) of the three genes were significantly greater than the average across the genomes. We further observed evidence for selection maintaining diversity on three genes in the Toll-Interleukin-1 receptor type of nucleotide binding/leucine-rich repeat immune receptor (TIR-NBS LRR) immunity-response signaling pathway, indicating that they could be vulnerable to pathogen effectors.

Abstract PD3-16: Clinical safety and efficacy of the aurora and angiogenic kinase inhibitor ENMD-2076 in previously treated, locally advanced or metastatic triple-negative breast cancer

Background: Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype defined by the lack of expression of the estrogen and progesterone receptors and lack of HER2 over-expression. ENMD-2076 is an orally bioavailable small molecule inhibitor of Aurora and angiogenic kinases with pro-apoptotic and antiproliferative activity in preclinical models of TNBC.

Methods: This two institution, single-arm, two-stage, phase II clinical trial enrolled patients with locally advanced or metastatic TNBC refractory to 1-3 prior lines of chemotherapy in the advanced setting. Patients had ECOG PS ≤ 1, measureable disease by RECIST 1.1 and no evidence of brain metastasis. Patients were treated with ENMD-2076 250 mg PO daily with continuous dosing in 4-week cycles until disease progression or unacceptable toxicity occurred. The primary end point was 6-month clinical benefit rate (6-CBR) and secondary endpoints included time to progression (TTP), PK profile, safety and biologic correlatives in archival and fresh serial tumor biopsies in a subset of patients.

Results: Between July 2012 and October 2016, 41 patients were enrolled (median age 54; range 30-73; female 40; male 1). Patients received a mean 1.7 prior lines of chemotherapy for locally advanced unresectable or metastatic disease and 80.5% received prior neoadjuvant or adjuvant chemotherapy (N=33). Thirty-six patients were evaluable per protocol for the primary efficacy analysis. Five patients (12.2%) were not included in the efficacy analysis due to: adverse events (AE) leading to discontinuation prior to objective efficacy assessment (N=3), not meeting eligibility criteria on day 1 (N=1) and withdraw of consent in cycle 1 (N=1). The study proceeded to the second stage of enrollment based on observing three 6-CBR events in Stage 1 (N=18 patients). The 6-CBR in the overall trial was 16.7% (95% exact CI: 6%-32.8%; 2 patients with PR and 4 patients with SD > 6 mos). The median duration of response or clinical benefit in these patients was 32 weeks (8 cycles). 4-CBR was 27.8% (95% exact CI: 14%-45.2%). Dose reduction occurred in 8 patients (20%) for fatigue, hypertension and proteinuria. The most common grade 3 treatment-related adverse events were hypertension (37.5%) and fatigue (10%). One patient experienced grade 4 hypertension. Analysis of serial tumor biopsies prior to and following 2 weeks of ENMD-2076 (N=8 patients), demonstrated a treatment-induced decrease in cellular proliferation (Ki-67) and microvessel density (CD34) as assessed by IHC. Immunofluorescence performed on a subset of samples demonstrated an increase in p53-family member expression following treatment, consistent with changes observed in preclinical TNBC patient-derived tumor xenograft models.

Conclusions: ENMD-2076 has durable clinical activity in a subset of patients with pretreated, advanced or metastatic triple-negative breast cancer. Predictive biomarker development using archival and fresh tumor tissue is underway. Exploration of lower doses of ENMD-2076 in future clinical trials may improve tolerability.

Citation Format: Diamond JR, Eckhardt SG, Pitts TM, van Bokhoven A, Aisner D, Gustafson DL, Capasso A, Elias AD, Storniolo AM, Schneider BP, Gao D, Tentler JJ, Borges VF, Miller KD. Clinical safety and efficacy of the aurora and angiogenic kinase inhibitor ENMD-2076 in previously treated, locally advanced or metastatic triple-negative breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD3-16.

Abstract P2-10-02: Basal biomarkers nestin and INPP4b predict gemcitabine benefit in metastatic breast cancer: Results from the phase III SBG0102 clinical trial

Background: A growing body of evidence is suggesting that basal-like and triple negative breast cancers may be particularly sensitive to nucleoside analogues (gemcitabine, capecitabine). In a prospective-retrospective analysis of the phase III SBG0102 clinical trial randomizing metastatic breast cancer patients to gemcitabine plus docetaxel (GD) or to higher-dose single agent docetaxel (D), patients with basal-like breast cancer by PAM50 gene expression had significantly better overall survival (OS) in the gemcitabine arm. By immunohistochemistry (IHC), triple negative status was not predictive, but is a poor surrogate for the basal-like intrinsic subtype. More accurate IHC biomarkers have since become available defining basal-like breast cancers by nestin positivity or by loss of inositol polyphosphate-4-phosphate (INPP4b).

Methods: Formalin-fixed paraffin embedded blocks of primary tumor tissue corresponding to 270 of the 337 patients participated in the SBG0102 trial were used to build tissue microarrays. IHC staining and interpretation for nestin and INPP4b by pathologists (who had no access to clinical data) followed published methods. A prespecified statistical plan was executed independently by Danish Breast Cancer Group statisticians, testing the primary hypothesis that patients with basal breast cancer – defined as positive for nestin or negative for INPP4b, regardless of ER/PR/HER2 status – would have superior OS on the GD treatment arm when compared to the D treatment arm by interaction test. Secondary outcomes included time to tumor progression (TTP) and response rate. Kaplan-Meier method with log-rank test of nestin and INPP4b status was used to measure OS and TTP. Forest plots were used to visualize predictive capacities relative to IHC markers and treatment effects.

Results: Two hundred fifty two cases were evaluable for this study, among which 38 (15%) had been classified as basal-like, 45 (18%) as HER2-Enriched, 74 (29%) as luminal A and 91 (36%) as luminal B by PAM50. Among 241 cases being evaluable for both IHC nestin and INPP4b markers, positive staining of nestin or loss of INPP4b was observed in 43 (17%) of the total cases and was significantly associated with PAM50 basal-like subtype (p<0.0001). Within a median follow up of 13 years, patients assigned as IHC-basal by virtue of being “nestin+ or INPP4b-” demonstrated a significantly lower OS when compared to non-basal cases defined as “nestin- and INPP4b+” (HR=2.45, 95% CI: 1.47-4.07) (p=0.0006). The IHC-basal patients did much better on the GD vs. the D arm (HR=0.36, 95% CI: 0.19-0.68) whereas there was no such difference in outcomes for other patients (HR=0.99). The interaction test was significant (p-interaction<0.005).

Conclusions: The nestin/INPP4b IHC panel offers a practical and inexpensive technology to identify basal-like patients. In the metastatic setting, women with IHC-basal breast cancers defined using these markers have superior overall survival when randomized to gemcitabine-containing chemotherapy compared to docetaxel alone.

Citation Format: Asleh-Aburaya K, Lyck Carstensen S, Burugu S, Gao D, Tykjær Jørgensen CL, Won JR, Jensen M-B, Balslev E, Lænkholm A-V, Nielsen DL, Ejlertsen B, Nielsen TO. Basal biomarkers nestin and INPP4b predict gemcitabine benefit in metastatic breast cancer: Results from the phase III SBG0102 clinical trial [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-10-02.

Abstract P2-03-01: Analytical validation of a standardized scoring protocol for Ki67 assessed on breast excision whole sections: An international multicenter collaboration

Aims: (i) Determine whether between-observer reproducibility for Ki67 when assessed on whole sections according to a standardized scoring protocol is adequate for clinical application. (ii) Compare between-observer reproducibility of Ki67 scores assessed on hot-spots to scores using a global method that averages across a tissue section.

Background: The nuclear proliferation biomarker Ki67 has multiple potential roles in breast cancer, including aiding decisions based on prognosis, but unacceptable levels of between-laboratory variability have been observed. The International Ki67 in Breast Cancer Working Group has undertaken a systematic program to determine whether Ki67 measurement can be analytically validated and standardized across labs. In phase 1, variability in visual interpretation was identified as an important source of variability. Phases 2 and 3a showed that adherence to defined scoring methods substantially improved reproducibility in scoring tissue microarrays and core-cut biopsies. We now assess whether acceptable reproducibility can be achieved on whole sections.

Methods: Adjacent sections from 30 primary ER+ breast cancers were centrally stained for Ki67 to assemble 4 sets of 30 stained tumor sections, circulated around 23 labs in 12 countries. Ki67 was scored by 2 methods by all labs: (a) global: 4 fields of 100 tumor cells each were selected to reflect observed heterogeneity in nuclear staining (b) hot-spot: the field with highest Ki67 percentage of tumor cells with nuclear staining was selected and up to 500 cells scored. Ki67 scores were log2-transformed for statistical analyses and back-transformed for presentation. The primary objective was to assess whether either method could achieve an intraclass correlation coefficient (ICC) significantly greater than 0.8, considered substantial to almost-perfect reproducibility. Secondary objectives were to assess which method had highest observed ICC and to assess whether observers identified the same “hot-spots”.

Results: ICC for the global method was 0.87 (95%CI: 0.799-0.93), marginally meeting the prespecified success criterion. The ICC for the hot-spot method was 0.83 (95%CI: 0.74-0.90) and had a CI extending below the success criterion. Across the 23 labs, geometric mean value of the 30 scores ranged from 8.5 to 19.6 for the global method and from 12.8 to 30.3 for the hot-spot method. The overall mean (95% CI) of these values was 12.9 (11.9-14.0) and 20.9 (19.1-22.8), respectively. Visually, between-laboratory agreement in location of selected hot-spot varies between cases. The median times for scoring were 9 and 6 minutes for global and hot-spot methods respectively.

Conclusions: The global method marginally met the prespecified criterion of success; it should now be evaluated for clinical validity in appropriate cohorts of cases. The hot-spot method was observed to have slightly less reproducibility between labs. The time taken for scoring by either method is practical using counting software we are making publicly available. Establishment of external quality assessment schemes is likely to improve the reproducibility between labs further.

(Supported by a grant from the Breast Cancer Research Foundation)

Citation Format: Nielsen TO, Leung SCY, Zabaglo LA, Arun I, Badve SS, Bane AL, Bartlet JMS, Borgquist S, Chang MC, Dodson A, Ehinger A, Fineberg S, Focke CM, Gao D, Gown AM, Gutierrez C, Hugh JC, Kos Z, Lænkholm A-V, Mastropasqua MG, Moriya T, Nofech-Mozes S, Osborne CK, Penault-Llorca FM, Piper T, Sakatani T, Salgado R, Starczynski J, Sugie T, van der Vegt B, Viale G, Hayes DF, McShane LM, Dowsett M. Analytical validation of a standardized scoring protocol for Ki67 assessed on breast excision whole sections: An international multicenter collaboration [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-03-01.

Abstract P3-05-12: VISTA expression on tumor-infiltrating lymphocytes in breast cancer: Clinical correlates and association with PD-1

Background: The V-domain containing Ig Suppressor of T Cell Activation (VISTA) is a recently discovered immune checkpoint receptor with homology to PD-1. VISTA expression on tumor-infiltrating lymphocytes (TILs) blocks their proliferation and effector functions. Recent pre-clinical data in cancer mouse models treated with anti-VISTA and anti-PD-L1 combinations showed promising results and non-redundant functions of VISTA and PD-L1 blockade. However, the expression and prognostic value of VISTA+ TILs in primary breast tumors has not been investigated in detail. Here we assess expression, prognostic value, and associations of VISTA+TILs with other immune checkpoint markers (PD-1/PD-L1, LAG-3, and IDO-1) and with H&E TIL counts.

Methods: A tissue microarray consisting of breast carcinoma primary excision specimens (n=330) from the University of British Columbia hospital, linked to detailed clinicopathological data and outcomes, was used in this study. Patients from this cohort did not receive neoadjuvant treatment. A VISTA antibody (Clone D1L2G) was applied on a 4μm section of the tissue microarray by immunohistochemistry using a Ventana automated stainer. VISTA+TILs in direct contact with tumor nest were scored and reported as absolute count per 0.6mm core. Positive cases were defined as cases with VISTA+TILs≥1. All descriptive and survival analyses were conducted using SPSS software.

Results: VISTA+TILs were present in 30% of cases and were significantly (p<0.05) associated with younger age (<50 years old), larger tumors (>2cm), hormone receptor negativity (ER/PR) and high Ki67proliferation index (≥13.25%). Almost half (48%) of basal-like breast cancers were positive for VISTA expressing TILs. No significant prognostic associations were observed in this cohort. Among the immune checkpoint receptors analyzed, VISTA+TILs were highly associated with PD-1+ TILs: 79% of cases positive for PD-1+TILs were also infiltrated by VISTA+TILs. Interestingly, we found that VISTA+TILs and PD-1+TILs were enriched in cases with otherwise low levels (<10%) of H&E TILs.

Conclusions: Our study identifies the presence of VISTA+TILs in breast cancer patients and its strong association with PD-1+TILs. These results suggest that VISTA blockade could be a good candidate for combination therapy with other immune checkpoint inhibitors, a concept being tested in early phase clinical trials. Validation of these findings in a larger independent cohort powered for multivariate analysis is currently ongoing.

Citation Format: Burugu S, Gao D, Nielsen TO. VISTA expression on tumor-infiltrating lymphocytes in breast cancer: Clinical correlates and association with PD-1 [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-05-12.

[Range of Hip Joint Motion and Weight of Lower Limb Function under 3D Dynamic Marker]

OBJECTIVES

To explore the range of reasonable weight coefficient of hip joint in lower limb function.

METHODS

When the hip joints of healthy volunteers under normal conditions or fixed at three different positions including functional, flexed and extension positions, the movements of lower limbs were recorded by LUKOtronic motion capture and analysis system. The degree of lower limb function loss was calculated using Fugl-Meyer lower limb function assessment form when the hip joints were fixed at the aforementioned positions. One-way analysis of variance and Tamhane's T2 method were used to proceed statistics analysis and calculate the range of reasonable weight coefficient of hip joint.

RESULTS

There were significant differences between the degree of lower limb function loss when the hip joints fixed at flexed and extension positions and at functional position. While the differences between the degree of lower limb function loss when the hip joints fixed at flexed position and extension position had no statistical significance. In 95% confidence interval, the reasonable weight coefficient of hip joint in lower limb function was between 61.05% and 73.34%.

CONCLUSIONS

Expect confirming the reasonable weight coefficient, the effects of functional and non-functional positions on the degree of lower limb function loss should also be considered for the assessment of hip joint function loss.

CEP55 promotes cell proliferation and inhibits apoptosis via the PI3K/Akt/p21 signaling pathway in human glioma U251 cells

Human glioma is one of the major malignancies worldwide with an increased mortality rate. Centrosomal protein of 55 kDa (CEP55) is an essential component of the CEP family and has been identified as a prognostic marker for multiple types of cancer. However, the function of CEP55 during glioma tumorigenesis remains unclear. In the present study, the data derived from the Oncomine database indicated that the expression of CEP55 is increased in glioma tissues compared with normal tissues. Furthermore, the expression of CEP55 was also increased at the level of mRNA and protein in glioma cell lines compared with normal human astrocytes. The knockdown of CEP55 expression inhibited the proliferation of glioma U251 cells, whereas overexpression of CEP55 induced the proliferation of U251 cells. Flow cytometric analysis indicated that the knockdown of CEP55 resulted in an increased number of cells arrested at G₂/M phase, and apoptosis was promoted. Further investigations revealed that the overexpression of CEP55 increased the phosphorylation of Akt and inhibited the activity of p21. By contrast, the knockdown of CEP55 resulted in the opposite effects. Taken together, the results of the present study suggested that CEP55 regulated the proliferation of glioma cells, further attributing to the carcinogenesis and progression of glioma via the PI3K/Akt/p21 signaling pathway. Therefore, CEP55 may be a novel therapeutic target for the treatment of glioma.

A Modified Equivalent Annulus Model for the Hollow Fiber Hemodialyzer

Experimental approaches to optimize hollow fiber hemodialyzer design are expensive and time-consuming. Computer modeling is an effective way to study mass transfer in the hemodialyzer because a substantial reduction in experimental time and cost can be achieved. This paper presents a two-dimensional modified “equivalent annulus” model, which employs Navier-Stokes (N-S) equations to describe blood and dialysate flow, and Kedem-Katchalsky (K-K) equations to calculate transmembrane flow. N-S equations and K-K equations must be coupled together in the process of computing. The corresponding experiments were designed to validate this model, and experimental results agreed well with numerical results. The distribution of velocity, pressure and solute concentration were investigated in detail, presenting a clear insight into dialyzer mass transfer. This model can be applied to help optimize hemodialyzer design.

Ultrafiltration Rate as a Dose Surrogate in Pre-Dilution Hemofiltration

For critically ill patients treated with continuous hemofiltration (HF), doses recently shown to improve survival can usually be achieved only in the pre-dilution mode. However, use of the pre-dilution mode results in reduced treatment efficiency, relative to post-dilution at the same ultrafiltration rate (Qf) and blood flow rate (Qb). The objective of this study is to determine the effect of Qf on removal parameters for solutes over a wide molecular weight spectrum in pre-dilution HF. Experiments were performed in an isovolemic, plasma-based pre-dilution system with Qb=200 ml/min. Removal parameters were measured for a 1.2 m2 polysulfone hemofilter (HF1200, Minntech) at Qf values of 20, 40, and 60 ml/min, corresponding to 17, 34 and 51 ml/h/kg for a 70 kg patient (N=3 hemofilters for each Qf). Clearance of urea and creatinine (small solute surrogates) was derived from plasma and ultrafiltrate concentrations at 30, 60, 120, 180, and 240 min while clearance of vancomycin and inulin (middle molecule surrogates) was estimated from changes in plasma concentrations over time. In addition, the sieving coefficient (SC) of vancomycin and inulin was measured at the same time points and at baseline (T=0 min). Our findings indicate pre-dilution had a predictable effect on clearance for each solute, as clearance increased linearly with Qf. Sieving coefficient values were not significantly influenced by either Qf or time and the equivalence of SC values in the middle molecule range suggest attenuation of secondary membrane effects. These data indicate filter performance can largely be preserved despite high Qf values by use of pre-dilution. Moreover, Qf appears to be a reasonable dose surrogate in pre-dilution HF.

Identification and genomic characterization of the emerging Senecavirus A in southeast China, 2017

Senecavirus A (SVA) is an emerging non-enveloped virus with a single-stranded, positive-sense RNA genome that belongs to the Senecavirus genus in the Picornaviridae family. Senecavirus A-associated swine idiopathic vesicular disease and epidemic transient neonatal losses have caused substantial economic losses for the swine industry. Here, we describe a case of re-emerging vesicular disease among sows and finishing pigs on a swine farm in Fujian Province of southeast China. Other causative pathogens, including FMDV, SVDV and VSV, were excluded, and a novel SVA strain, CH-FJZZ-2017, was isolated. Sequencing and phylogenetic analysis of the complete genome and individual viral proteins revealed that CH-FJZZ-2017 is closely related to the US strains in 2015. The results further showed that Chinese SVAs have formed two distinct subclades with 2016 as the turning point. Viruses causing outbreaks after late 2016 shared higher nucleotide identities with the US strains in 2015. There is still some evolutionary distance between CH-FJZZ-2017 and other strains isolated in late 2016, suggesting that Chinese SVA isolates have been evolving in different directions. This study provides a basis for the development of effective prevention and control strategies.

Inhibition of PAR2 and TRPA1 signals alleviates neuropathic pain evoked by chemotherapeutic bortezomib

Bortezomib (BTZ) is generally used as a chemotherapeutic agent for the treatment of multiple myeloma; however, one of the significant limiting complications of BTZ is painful peripheral neuropathy observed during BTZ therapy. There is a lack of drugs which can prevent and/or treat the painful symptoms induced by BTZ, as the underlying molecular mechanism leading to neuropathic pain remains largely unclear. In the present study, we examined engagement of proteinase-activated receptor 2 (PAR2) and transient receptor potential ankyrin 1 (TRPA1) in neuropathic pain induced by BTZ in rats. Our results demonstrated that systemic injection of BTZ increased mechanical pain and cold sensitivity as compared with control animals (P less than 0.05 vs control rats). Our data further showed that blocking respective PAR2 and TRPA1 attenuated mechanical pain and cold sensitivity observed in control rats and BTZ rats (P less than 0.05 vs vehicle control). Notably, the attenuating effect of blocking PAR2 and TRPA1 on mechanical pain and cold sensitivity was significantly less in BTZ rats than that in control rats. In addition, protein expression of PAR2 and TRPA1 was upregulated in the lumbar dorsal root ganglion of BTZ rats, and inhibition of PAR2 decreased the levels of TRPA1 and attenuated its downstream pathways (namely, PKCɛ and PKA). Overall, we revealed specific signaling pathways leading to neuropathic pain induced by chemotherapeutic BTZ and that blocking PAR2 and TRPA1 in sensory nerves is beneficial to improve neuropathic pain during BTZ intervention.

Osmotic Separation of Pancreatic Exocrine Cells from Crude Islet Cell Preparations

A novel approach is introduced here to selectively lyse exocrine cells in an islet preparation by hypoosmotic treatment. Time to hypotonic cell lysis required for the islet cells was much longer than that for the exocrine cells, which permits a possibility of selectively killing the exocrine cells by hypotonic treatment. The first set of experiments was designed to select an appropriate osmolality for the hypotonic treatment. Kinetic changes in cell volume in response to extracellular anisosmolalities (30 to 90 mOsm/kg) were recorded using an electronic particle counter. The results indicated that, when exposed to a 30 mOsm/kg solution, islet cells swelled slowly to reach volumetric equilibrium in approximately 3 min. There was no significant hypotonic cell lysis observed even at the end of 4 min (n = 4). In contrast, pancreatic exocrine cells, when exposed to the same solution, expanded rapidly to the lytic volume and burst within 30 s. Significant exocrine cell lysis was invariably achieved within 30 s when cells were exposed to the osmolalities below 60 mOsm/kg. For osmolalities between 70 to 80 mOsm/kg, exocrine cell lysis was highly variable. When cells were exposed to 80 to 90 mOsm/kg, no significant cell lysis was observed. Thus, an osmolality of 50 mOsm/kg is recommended for hypotonic treatment, as it maximizes the lysis of exocrine cells without unnecessarily stressing (osmotically) the islet cells. The second set of experiments (time-course experiments, 20 to 120 s) was designed to determine the length of exposure time for which the exocrine cells were irreversibly damaged but the islet cells had only swollen to such a degree that cell function is restored upon returning to an isotonic condition. Viability of the hypotonic treated cells was evaluated at two different levels: membrane integrity, measured by combined fluorescent dye staining with propidium iodide (PI) and carboxyfluorescein diacetate (CFDA), and mitochondrial function, measured by colorimetric MTT assay. The results showed that hypotonic treatment in a 50 mOsm/kg solution for 30 s resulted in over 85% loss of the membrane integrity for the exocrine cells. About 90% of these membrane lysed cells lost mitochondrial function (n = 3). By contrast, under the same treatment, less than 15% of the islet cells lost membrane integrity and mitochondrial function (n = 3). In conclusion, hypotonic treatment with a 50 mOsm/kg solution for 20 to 30 s at room temperature is sufficient to lyse the majority of the contaminating exocrine cells in an islet cell preparation, while maintaining function in the islet cells.

CUEDC2 suppresses glioma tumorigenicity by inhibiting the activation of STAT3 and NF-κB signaling pathway

CUEDC2, a CUE domain containing 2 protein, plays critical roles in many biological processes, such as cell cycle, inflammation and tumorigenesis. However, whether CUEDC2 was involved in tumorigenesis of glioma and the possible mechanism remains to be elucidated. In the present study, our results implied that the expression of CUEDC2 was lower in the glioma tissue and glioma cell lines than that of normal tissue and asctrocyte cells. Downregulation of endogenous CUEDC2 in glioma U251 cell lines by RNAi promoted the tumor cells proliferation, migration, invasion and glioma neurosphere formation, while, overexpression of CUEDC2 showed the opposite effect. Further studies showed that overexpression of CUEDC2 suppressed the activation and nuclear translocation of phosphorylated-STAT3 (p-STAT3) but the level of p-STAT3 increased after interfering with the expression of CUEDC2. Moreover, CUEDC2 expression has an inhibitory effect on the activation of NF-κB. Thus, our studies suggested that the decreased expression of CUEDC2 in glioma led to the activation of transcription factor STAT3 and NF-κB signaling pathway which may be related to the tumorigenicity in glioma.

High-salt diet induces outward remodelling of efferent arterioles in mice with reduced renal mass

AIM

The glomerular filtration rate (GFR) falls progressively in chronic kidney disease (CKD) which is caused by a reduction in the number of functional nephrons. The dysfunctional nephron exhibits a lower glomerular capillary pressure that is induced by an unbalance between afferent and efferent arteriole. Therefore, we tested the hypothesis that oxidative stress induced by CKD differentially impairs the structure or function of efferent vs. afferent arterioles.

METHODS

C57BL/6 mice received sham operations (sham) or 5/6 nephrectomy (RRM) and three months of normal- or high-salt diet or tempol. GFR was assessed from the plasma inulin clearance, arteriolar remodelling from media/lumen area ratio, myogenic responses from changes in luminal diameter with increases in perfusion pressure and passive wall compliance from the wall stress/strain relationships.

RESULTS

Mice with RRM fed a high salt (vs. sham) had a lower GFR (553 ± 25 vs. 758 ± 36 μL min^-1  g^-1 kidney, P < 0.01) and a larger efferent arteriolar diameter (9.6 ± 0.8 vs. 7.4 ± 0.7 μm, P < 0.05) resulting in a lower media/lumen area ratio (1.4 ± 0.1 vs. 2.4 ± 0.2, P < 0.01). These alterations were corrected by tempol. The myogenic responses of efferent arterioles were about one-half that of afferent arterioles and were unaffected by RRM or salt. Passive wall compliance was reduced by high salt in both afferent and efferent arterioles.

CONCLUSION

A reduction in renal mass with a high-salt diet induces oxidative stress that leads to an outward eutrophic remodelling in efferent arterioles and reduced wall compliance in both afferent and efferent arterioles. This may contribute to the lower GFR in this model of CKD.

Abstract PD5-08: Expression of LAG-3 in breast cancer, and its association with subtype and outcome

Aim: To investigate the expression and clinical value of the immune checkpoint marker LAG-3 in breast cancer patients

Background: Lymphocyte-activation gene 3 (LAG-3) is a recently discovered immune checkpoint biomarker that is targeted by agents currently being evaluated in early phase clinical trials. LAG-3 functions as a cell surface receptor expressed following T cell activation and negatively impacts T cell functions. This biomarker has not yet been evaluated in large series of breast cancers with long term treatment and outcome data, in the context of subtype and other immune biomarkers.

Methods: Two tissue microarray series (a training set with N=330 and a validation set with N = 2203 patients) were constructed from breast carcinoma primary excision specimens from University of British Columbia hospitals, linked to detailed clinical and pathological data. None of these patients had received neoadjuvant treatment. 4µm sections were stained with an antibody to LAG-3 (clone 17B4) by immunohistochemistry using a Ventana Discovery Ultra automated slide stainer. LAG-3+ stromal and intra-epithelial tumor infiltrating lymphocytes (TILs) were reported as absolute counts per tissue microarray core. Stromal TILs (sTIL) were defined as lymphocytes present in the stroma not in direct contact with tumor nest whereas intra-epithelial TIL (iTIL) were lymphocytes in direct contact with carcinoma cells. All descriptive and survival analyses were conducted using SPSS software.

Results: LAG-3+ sTILs were found in 16% of breast cancer cases in both the training set and the validation set; LAG-3+iTILs were present in 14 and 11%, respectively. In both the training set and the validation set, the presence of LAG-3 (iTILs or sTILs) was significantly (p&lt;0.001) associated with high grade tumors, estrogen and progesterone receptor negativity, high Ki67 index and with the HER2+ and basal-like subtypes. In survival analyses of ER negative patients, in both sets patients with LAG-3 T cells (iTILs or sTILs) had a significantly improved disease-specific survival (p&lt;0.05). As with other lymphocyte biomarkers, this association was not observed among ER+ patients.

Conclusions: LAG-3+TILs are present in breast cancer and are associated with major risk factors and hormone receptor negative subtypes. ER negative breast cancer patients have a better outcome if they contain LAG-3+ TILs, consistent with published data showing better survival among ER- breast cancer patients with immune infiltrates. More than a quarter of ER negative breast cancers contain TILs expressing LAG3, and may represent the most relevant subset to target with emerging checkpoint inhibitors targeting this T cell surface receptor.

Citation Format: Burugu S, Gao D, Nielsen TO. Expression of LAG-3 in breast cancer, and its association with subtype and outcome [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD5-08.

Abstract P1-09-08: Predictive effect of cytotoxic tumor infiltrating lymphocytes in HER2-positive metastatic breast cancer: A correlative study with CCTG MA.31

Background and Objectives: The presence of tumor infiltrating lymphocytes (TILs), particularly CD8+ cytotoxic T-cells, has been associated with improved prognosis in patients with HER2+ breast cancer. Increasing levels of TILs also appear to predict response to adjuvant trastuzumab in early breast cancer, although they did not predict benefit of combined trastuzumab-lapatinib neoadjuvant dual therapy over monotherapy in NeoALLTO. CCTG MA.31 randomized 652 women with HER2+ metastatic breast cancer to treatment with trastuzumab (T) vs. lapatinib (L), in combination with taxane (Tax) chemotherapy for 24 weeks, followed by the same HER2-targeted monotherapy. Final results from MA.31 found trastuzumab was superior to lapatinib for the primary endpoint of progression free survival (PFS): the hazard ratio (HR) for lapatinib to trastuzumab was 1.37 (95% CI, 1.13-1.65). Although both agents block HER2 signaling, trastuzumab has additional mechanisms of action via the immune system. We hypothesized that TIL levels may predict response to HER2-targeted therapy (trastuzumab vs. lapatinib).

Methods: MA.31 included HER2+ metastatic breast cancer patients, median age 55 years, and median follow-up 21.5 months. Overall TILs were counted per published guidelines on the original H&E stained sections used for pathology review at study entry. Immunohistochemistry (IHC) was performed on unstained sections from tissue microarrays or individual formalin-fixed paraffin-embedded blocks to test expression of lymphocyte biomarkers CD8, FOXP3, CD56 and PD-1 on stromal and intra-tumoral TILs (sTILs, iTILs). Statistical analysis was conducted by CCTG for a total of 9 prespecified biomarker tests. Associations of TILs with PFS were evaluated by univariate stratified log-rank test with graphical Kaplan-Meier curves, and by stratified multivariate Cox proportional hazards regression analysis. Predictive effect was examined with a test of interaction between treatment allocation and biomarker classification (high vs. low, using pre-established cutpoints).

Results: Of the 652 cases, 614 had slides for overall TIL assessment and 427 for IHC biomarker assessments. In this correlative study set, superiority of trastuzumab over lapatinib for PFS was confirmed in multivariate analysis (LTax/T vs. TTax/L: HR = 2.55, 95% CI = 1.43-4.55, p = 0.001). TIL counts by H&E were neither prognostic nor predictive in this set of metastatic HER2+ breast cancers. Lymphocyte IHC markers were not prognostic. However, prespecified stratified univariate analysis detected a significantly higher risk for lapatinib over trastuzumab (HR = 2.94, 95% CI = 1.40-6.17, p = 0.003) in patients with low CD8+ sTIL (&lt; 3) than was observed among those with high CD8+ sTIL (HR = 1.36, 95% CI = 1.05-1.75, p = 0.019). This differential effect was confirmed in multivariate analysis (interaction test p = 0.042). The other tested biomarkers did not demonstrate significant predictive effects.

Conclusions: In this correlative study of metastatic HER2+ breast cancer, a low level of pre-existing stromal cytotoxic T cell infiltration predicts women who benefit most from trastuzumab over lapatinib. Overall TIL counts were neither prognostic nor predictive.

Citation Format: Liu S, Chen B, Burugu S, Leung S, Gao D, Virk S, Kos Z, Parulekar WR, Shepherd L, Gelmon K, Nielsen TO. Predictive effect of cytotoxic tumor infiltrating lymphocytes in HER2-positive metastatic breast cancer: A correlative study with CCTG MA.31 [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-09-08.

Effects of NMDA-Receptor Antagonist on the Expressions of Bcl-2 and Bax in the Subventricular Zone of Neonatal Rats with Hypoxia-Ischemia Brain Damage

Neonatal hypoxia-ischemia brain damage is an important cause of death by affecting prognosis of neural diseases. It is difficult to find effective methods of prevention and treatment due to the complexity of its pathogenesis. N-methyl-D-aspartate (NMDA), as an excitotoxicity amino acids, has proven to play an important role in hypoxic-ischemic. However, the exact effects of the NMDA subunits, NR2A and NR2B, during hypoxic-ischemic have not been investigated in detail. Therefore, we sought to study whether the NMDA receptor antagonist could confer neuroprotective effects in a neonatal rat hypoxia-ischemia model. The effects of intraperitoneal injections of different drugs, namely MK-801 (0.5 mg/kg), NVP-AAM077 (5 mg/kg), and Ro25-6981 (5 mg/kg), on the expressions of anti-apoptotic protein Bcl-2 and apoptosis protein Bax in the subventricular zone were analyzed by immunohistochemical staining to explore the roles of NMDA subunits (NR2A and NR2B) in hypoxic-ischemic. We found that the NR2B antagonist (Ro25-6981) could inhibit hypoxic-ischemic with the increasing Bcl-2 expression. NR2A antagonists (NVP-AAM077) can increase cerebral hypoxia-ischemia in neonatal rats, promoting the expression of apoptotic protein Bax.