Abstract GS2-01: Discovery and characterization of an estrogen bound LncRNA in late-Stage breast cancer

Breast cancer is the second most common newly diagnosed cancer and the second leading cause of cancer death among women in the United States. Despite the proven benefits of adjuvant endocrine therapy in women with hormone receptor positive breast cancer, relapses still occur over 5 years after initial treatment with endocrine therapy, referred to as late-stage relapse. Currently, the mechanisms of driving late-stage relapse are poorly characterized. To date, breast cancer research has primarily focused on protein-coding genes thereby missing the emerging class of long intergenic non-coding RNAs (lncRNAs) that may serve as critical regulators of relapse. Furthermore, the current understanding of lncRNA function is still in its infancy representing a critical gap for translating lncRNA discoveries into real-world applications to benefit patient care. Several well-described examples indicate that lncRNAs may be master epigenetic regulators in cancer biology through their interactions with proteins regulating target gene expression. Therefore, we hypothesize that lncRNAs may interact with estrogen receptor alpha 1 (ESR1) to regulate genes promoting late-stage relapse. To address this, we performed a transcriptome analysis of tumors from a unique cohort of 24 patients that had late-stage relapse to discover a novel set of lncRNAs, most of which have not yet been characterized. Next, we used RNA Immunoprecipitation coupled with transcriptome sequencing (RIP-Seq) to identify transcripts bound to ESR1 in T47D cells. We discovered 217 lncRNAs bound to ESR1 of which 50 were up-regulated in late-stage breast cancer. We chose to focus the most up-regulated lncRNA in late-stage relapse. Since it is an unannotated lncRNA we will refer to it as 'LAte-Stage relapse ESR1-Bound lncRNA 1', or LASER-1. To further understand the interplay between LASER-1 and ESR1, cells endogenously expressing LASER-1 were subjected to partial digestion to preserve lncRNA and protein interactions. Protected RNA fragments were subsequently immunoprecipitated with ESR1 and quantified by qPCR to reveal specific ESR1 interaction sites within LASER-1. Next, we observed increased expression of LASER-1 in ER+ breast cancer cell lines. Notably, LASER-1 expression was elevated in MCF7 long-term estrogen deprived (MCF7 LTED) cells -- that have amplified ESR1 -- relative to parental MCF7 cells. To demonstrate that LASER-1 promotes oncogenic phenotypes we transiently silenced LASER-1 in two cell lines with high endogenous expression of LASER-1 (including MCF LTED) and observed a decrease in cellular proliferation and invasion. Subsequent gene expression analysis after silencing LASER-1 altered mRNA and protein levels of critical cell cycle genes (i.e., p27). Overall, this is the first study to discover ESR1 bound lncRNAs that may be contributing to late-stage relapse in breast cancer. In the short-term, our ongoing research may lead to significant breakthroughs establishing the importance of LASER-1 as a master regulator in late-stage relapse. In the longer-term, we envision this research may lead to the development of novel therapeutics targeting LASER-1 with the potential for rapid clinical translation.

Citation Format: Maher CA, Silva-Fisher J, Eteleeb A, Tang C, Perou C, Reis-Filho JS, Mardis ER, Ellis MJ. Discovery and characterization of an estrogen bound LncRNA in late-Stage 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 GS2-01.

Intonational speech prosody encoding in the human auditory cortex

Speakers of all human languages regularly use intonational pitch to convey linguistic meaning, such as to emphasize a particular word. Listeners extract pitch movements from speech and evaluate the shape of intonation contours independent of each speaker's pitch range. We used high-density electrocorticography to record neural population activity directly from the brain surface while participants listened to sentences that varied in intonational pitch contour, phonetic content, and speaker. Cortical activity at single electrodes over the human superior temporal gyrus selectively represented intonation contours. These electrodes were intermixed with, yet functionally distinct from, sites that encoded different information about phonetic features or speaker identity. Furthermore, the representation of intonation contours directly reflected the encoding of speaker-normalized relative pitch but not absolute pitch.

Experimental warming and antecedent fire alter leaf element composition and increase soil C:N ratio in sub-alpine open heathland

Plant communities in alpine ecosystems worldwide are being altered by climate warming. In the alpine open heathland of the Bogong High Plains, Australia, warming and fire have affected the growth and phenology of plants, and have recently been found to alter soil nutrient availability. We examined the effects of nine years of passive warming by open-top chambers and nine years post-fire on (i) the soluble and extractable nutrients and toxic elements available for plant uptake in the soil and (ii) on the element composition of leaves of seven dominant sub-alpine open heathland plants. Warming increased soil C, soil C:N, and decreased soil δ¹³C, indicating an accumulation of soil organic matter and C sequestration. Warming increased soil δ¹⁵N, indicating increased N mineralization, which concurred with the increased availability of NH₄⁺ (measured by ion-exchange membranes). Leaf element composition varied among the plant species in response to changes in soil element availabilities, suggesting the importance of species-specific knowledge. Warming decreased leaf N concentration and increased leaf C:N, generally in the plant community, and specifically in Asterolasia trymalioides, Carex breviculmis, Poa hiemata, and Rytidosperma nudiflorum. Warming increased soil P availability, but did not significantly affect leaf P in any species. Antecedent fire increased soil C:N, and decreased concentrations of Ca and Mg in Celmisia pugioniformis more than in the other species. The results suggest that warming and fire changed the nutrient composition of plants and increased soil C:N, which might lead to progressive N limitation in the alpine ecosystem.

[Application of " Internet Plus" AIDS prevention services among men who have sex with men in Guangzhou, China: results from 2010 to 2015]

Objective: To introduce the development strategy of " Internet Plus" AIDS prevention services and its implementation results from 2010 to 2015 in Guangzhou, China. Methods: A gay men's health column was created for an active website aimed at men who have sex with men(MSM), in collaboration with local community organizations and the Guangzhou CDC. We designed intervention tools(including scenario-based applications and HIV risk self-assessment systems)and an online HIV testing service platform, integrated with applied psychology and behavioral theory as well as the " Internet Plus" concept, to intervene in HIV infection risk factors among MSM. Data of clients who accessed the " Internet Plus" AIDS services from 2010 to 2015 were used to evaluate service operation. Six-year consecutive surveys, conducted between April and July of each service year, were collected using a national AIDS sentinel surveillance questionnaire. For each year of surveillance, information on HIV prevalence, HIV interventions received during the past year, unprotected anal intercourse in the past 6 months, and HIV testing in the past year were compared using the chi-squared(χ²)test, to roughly reflect the effect of"Internet Plus" AIDS prevention services. Results: As of 31 December 2015, a total of 34 395 MSM had received " Internet Plus" services and HIV testing. The number of MSM tested increased from 2 338 in 2010 to 8 054 in 2015. From 2010 to 2015, newly identified HIV cases in each year were 59, 166, 312, 283, 291, and 270, which accounted for 25.0%, 32.8%, 38.8%, 35.1%, 30.5%, and 23.2% of MSM HIV cases of Guangzhou, respectively. Sentinel surveillance data showed that during the study period, 3 047 MSM were investigated, with 405, 400, 401, 633, 608, and 600 each year, respectively. The proportion of participants who had received any HIV intervention during the past year was 74.3%(301), 70.8%(283), 83.3%(334), 85.0%(538), 69.1%(420), and 83.8%(503)each year, respectively(trend χ²=6.53, P=0.011). HIV testing done during the past year accounted for 44.0%(178), 44.3%(177), 49.4%(198), 53.4%(338), 56.1%(341), and 60.2%(361)each year, respectively(trend χ²=40.83, P<0.001). Unprotected anal intercourse in the past 6 months accounted for 59.3%(240), 62.0%(248), 56.6%(227), 57.0%(361), 48.4%(294), and 43.7%(262)each year, respectively(trend χ²=42.21, P<0.001). Conclusion: The"Internet Plus"AIDS prevention services in this study represent a manner to enhance traditional HIV prevention strategies. We found these services to be effective in implementation of the national AIDS control and prevention strategy, especially for the expansion of intervention, testing, and case identification among high-risk populations.

Aspartate β-hydroxylase disrupts mitochondrial DNA stability and function in hepatocellular carcinoma

The mechanism of aberrant mitochondrial genome and function in hepatocellular carcinoma (HCC) remains largely unknown. Our previous study demonstrated an increased expression of aspartate β-hydroxylase (ASPH) in HCC tissues, which was associated with tumor invasiveness and a worse prognosis. Currently, we unexpectedly observed the presence of ASPH in purified mitochondrial protein fraction. In addition, immunostaining of both exogenously and endogenously expressed ASPH showed a colocalization with mitochondrial biomarkers. This study aimed to investigate whether the mitochondrial ASPH is involved in mitochondrial malfunction in HCC. Our results showed that ASPH overexpression in HCC tissues was correlated with decreased copy numbers of displacement loop (D-loop) and NADH dehydrogenase subunit 1 (ND-1) and enhanced D-loop mutation, suggesting the disrupted mitochondrial DNA (mtDNA) stability. The reduced mtDNA copy numbers were associated with aggressive clinicopathological features of HCC. The loss of mtDNA integrity induced by enforced expression of ASPH was accompanied with mitochondrial dysfunction, which was characterized by the aberrant mitochondrial membrane potential, decreased ATP generation and enhanced reactive oxygen species. In contrast, knocking down ASPH by siRNA in HCC cell lines showed the opposite impact on mtDNA integrity and function. Mass spectrometry and co-immunoprecipitation further identified that ASPH interacted with histone H2A member X (H2AX). ASPH overexpression diminished the interaction between H2AX and mitochondrial transcription factor A (mtTFA), an important DNA-binding protein for mtDNA replication, which then reduced the binding of mtTFA to D-loop region. Collectively, our results demonstrate that ASPH overexpression disrupts the mtDNA integrity through H2AX-mtTFA signal, thereby affecting mitochondrial functions in HCC.

Identification and measurement of staphylococcal enterotoxin M from Staphylococcus aureus isolate associated with staphylococcal food poisoning

Staphylococcus aureus produces a wide variety of staphylococcal enterotoxins (SEs, SEA to SEX), which are responsible for staphylococcal food poisoning. This study is aimed to establish a system to detect staphylococcal enterotoxin M (SEM) protein in food matrixes. In the present study, sem gene was characterized in a S. aureus isolate H4 associated with food poisoning. The amino acid sequence of the deduced SEM protein was same as that of previously identified SEM from S. aureus 04-02981. Subsequently, mature SEM protein was expressed in Escherichia coli BL21 (DE3) cells and purified with a Ni-NTA spin column. The polyclonal and monoclonal antibody against it were prepared. Using these antibodies, a highly sensitive, specific sandwich enzyme-linked immunosorbent assay (ELISA) system was developed capable of detecting SEM in milk, meat and rice. Cross-reactivity with SEB, SEI and SEK in this method was insignificant. Quantification of SEM secretion in vitro using this novel capture ELISA revealed that SEM was mainly secreted during the transition from the exponential to the stationary phase. Furthermore, sem gene and SEM protein production were screened by PCR and the developed ELISA system. The results indicated that there were two SEM+ strains of 19 S. aureus isolates originating in cold dishes and humans suffering from food poisoning. The investigations make it possible to assess SEM in food hygiene supervision in near future.

SIGNIFICANCE AND IMPACT OF THE STUDY

Staphylococcal enterotoxins (SE) are the main causative agents of staphylococcal food poisoning. Unlike classical SEs (SEA to SEE), the relationship between newly identified SEs (SEG to SEX) and staphylococcal food poisoning has not been clearly elucidated. Recently, mild emetic potential of staphylococcal enterotoxin M (SEM) has been demonstrated, which indicated that SEM might be associated with food poisoning. However, there is currently no commercial enzyme-linked immunosorbent assay (ELISA) kit available for immunological detection of it. Therefore, we developed a highly sensitive, specific sandwich ELISA system and assayed SEM in food matrixes. This assay facilitates the study of SEM expression in vitro and in vivo. In addition, the investigations would be helpful in addressing the relative incidence of SEM+ strains in near future.

Identification and measurement of staphylococcal enterotoxin-like protein I (SEll) secretion from Staphylococcus aureus clinical isolate

AIMS

Staphylococcus aureus (Staph. aureus) produces a wide variety of staphylococcal enterotoxins (SEs) and staphylococcal enterotoxin-like (SEl) proteins, which are the most causative agents of staphylococcal food poisoning. In contrast to classical SEs (SEA to SEE), the relationship between the novel SEs/SEls (SEG to SElX) and staphylococcal food poisoning is not elucidated. This study is aimed to establish a system to detect staphylococcal enterotoxin-like protein I (SElI) for analysis of staphylococcal food poisoning.

METHODS AND RESULTS

SElI was characterized in a Staph. aureus clinical isolate associated with food poisoning; there was an amino acid substitution Thr145Ala compared to previously identified SEI from Staph. aureus 04-02981. Subsequently, SElI was expressed, purified, and the poly- and monoclonal antibodies against it were prepared. Using these antibodies, a highly sensitive sandwich enzyme-linked immunosorbent assay (ELISA) that specifically detected and measured SElI secretion from the Staph. aureus clinical isolate in LB medium, milk and bloodstream was developed.

CONCLUSIONS

The ELISA system has been successfully applied for analysing SElI secretion in vivo and in vitro.

SIGNIFICANCE AND IMPACT OF THE STUDY

The highly sensitive ELISA should make it attractive for quantifying SElI in food hygiene supervision and clinical diagnosis in near future.

Potential role of biochars in decreasing soil acidification - A critical review

A large number of soils, worldwide, are acid (normally pH<5.5) and suffering from on-going soil acidification. Acid soils or soils undergoing acidification generally have low fertility and low crop productivity. Biochars have been reported to be of potential value in agriculture for improving soil properties and in reducing the hazards caused by soil acidification and in naturally acidic soils. However, the ameliorant effects of biochars on acid soils and the mechanisms involved have not previously been critically reviewed. Here we summarize the phenomena, and mechanisms involved in the improvement of soil acidity by biochars, the alleviation of aluminum toxicity, the enhancement of nutrient availability, and changes in nitrification by collating data in the literature. In addition, the agronomic effectiveness and environmental concerns in the incorporation of biochar and other soil additives (i.e. lime, industrial by-products, organic wastes and plant residues) to acid soils are systemically compared. We conclude that biochar is a potentially effective amendment to reverse or to prevent acidification in acid soils. Finally, perspectives for further research in terms of soil acidification are presented to address some issues that are still poorly understood and/or highly controversial.

Giant frequency down-conversion of the dancing acoustic bubble

We have demonstrated experimentally the existence of a giant frequency down-conversion of the translational oscillatory motion of individual submillimeter acoustic bubbles in water in the presence of a high frequency (500 kHz) ultrasonic standing wave. The frequency of the translational oscillations (~170 Hz) is more than three orders of magnitude smaller than that of the driving acoustic wave. We elucidate the mechanism of this very slow oscillation with an analytical model leading to an equation of translational motion of a bubble taking the form of Mathieu's equation. This equation illuminates the origin of the giant down conversion in frequency as arising from an unstable equilibrium. We also show that bubbles that form chains along the direction of the acoustic standing wave due to radiation interaction forces exhibit also translation oscillations that form a spectral band. This band extends approximately from 130 Hz up to nearly 370 Hz, a frequency range that is still at least three orders of magnitude lower than the frequency of the driving acoustic wave.

944 mJ Nd:YAG planar waveguide laser amplifier with the optical to optical efficiency of 52

We demonstrated a quasi-continuous wave (QCW) Nd:YAG planar waveguide laser amplifier with the single pulse output energy of 944 mJ. At the pulse repetition frequency (PRF) of 100 Hz, 1064 nm seed laser was coupled into the planar waveguide laser amplifier with the single pulse energy of 128 mJ and the pulse duration of 192 μs. With the total pump energy of 1582 mJ, the extracted energy of 816 mJ was obtained, leading to an optical to optical efficiency of 52% and an electrical to optical efficiency of 28%. To the best our knowledge, it is up to now the highest efficiency and output energy in Nd:YAG planar waveguide laser amplifier reported. At the maximum output, the beam quality factors M2 were measured to be 3.44 and 4.81 in the guided direction and unguided direction respectively, and the polarization degree was 98.6%. Higher average power could be obtained with the better performance of seeder oscillator.

The Prevalence, Clinical, and Molecular Characteristics of Congenital Hypothyroidism Caused by DUOX2 Mutations: A Population-Based Cohort Study in Guangzhou

Thyroid dyshormonogenesis (DH) has recently been reported to be more frequently associated with mutations in the dual oxidase 2 (DUOX2) gene. The present study was aimed to investigate the prevalence, clinical, and molecular characteristics of congenital hypothyroidism (CH) caused by DUOX2 mutations in Guangzhou. A population-based cohort of 156 patients with CH was recruited based on neonatal screening among 433 578 newborns born in Guangzhou from 2011 to 2012. Genetic analysis of DUOX2 was performed in 96 patients with suspected thyroid dyshormonogenesis (SDH) by PCR-amplified direct sequencing. Apart from 2 cases without ultrasonographic data, 118 (76.6%) of the 156 patients were classified as SDH and 36 (23.4%) as thyroid dysgenesis (TD) according to thyroid ultrasound at diagnosis. Genetic analysis revealed 23 different variants in 60 unrelated individuals (60/96, 62.5%), including 13 novel variants that were absent from HGMD, dbSNP databases, and the 50 normal controls. The novel missense variants were predicted to be pathogenic by SIFT and PolyPhen-2. The p.K530X was the most common mutation. Ninety-three percent of mutant alleles occurred in exons 5, 6, 9, 14, 17, 20, 25, 27, and 28. There were no significant differences in phenotypes between biallelic and monoallelic variants cases or between with-DUOX2 and non-DUOX2 variants cases. Most patients with DUOX2 defects (78.2%) were transient CH. In conclusion, the prevalence of DUOX2 pathogenic variants was high (62.5%) in this cohort. Thirteen novel probably pathologic variants were reported. The p.K530X was the most common mutation in the Chinese population. There was no correlation between DUOX2 genotypes and clinical phenotypes.

Lubricity of gold nanocrystals on graphene measured using quartz crystal microbalance

In order to test recently predicted ballistic nanofriction (ultra-low drag and enhanced lubricity) of gold nanocrystals on graphite at high surface speeds, we use the quartz microbalance technique to measure the impact of deposition of gold nanocrystals on graphene. We analyze our measurements of changes in frequency and dissipation induced by nanocrystals using a framework developed for friction of adatoms on various surfaces. We find the lubricity of gold nanocrystals on graphene to be even higher than that predicted for the ballistic nanofriction, confirming the enhanced lubricity predicted at high surface speeds. Our complementary molecular dynamics simulations indicate that such high lubricity is due to the interaction strength between gold nanocrystals and graphene being lower than previously assumed for gold nanocrystals and graphite.