Abstract P3-03-04: Not presented

This abstract was not presented at the symposium.

Abstract PD2-01: Ultrasound together with clinical indexes cannot predict sentinel lymph node metastasis for ultrasound-axillary lymph node-negative breast cancer patients

Background: Sentinel lymph node (SLN) pathology result is crucial to predict axillary lymph nodes (ALN) metastasis as well as to determine systemic treatment strategy. Ultrasound has been paid great attention to the evaluation of ALN metastasis. Whether the combination of known clinic-pathological indexes to ultrasound could predict SLN metastasis for ultrasound-ALN-negative breast cancer, and ultimately achieve the goal of avoiding the invasive method of sentinel lymph node biopsy (SLNB), is the current focus.

Objective: To discuss the possibility of predicting SLN metastasis using axillary ultrasonography in combination with patients' clinic-pathologic factors by retrospectively analyzing our institution's large cohort of ultrasound-ALN-negative breast cancer patients' data.

Method: This study collected consecutive data from the prospective database of Breast Center of Beijing Cancer Hospital from Oct. 2010 to Apr. 2016. Inclusion criteria: Pathologically diagnosed as primary breast cancer by core needle biopsy (CNB); negative ALN by ultrasound (no ALN detected, or the cortex thickness was even and <3mm); no treatment prior to SLNB. The SLN pathological outcomes were correlated with known clinic-pathologic parameters. Univariate analysis was performed by Chi-Square test, with p<0.05 considered as statistically significant difference. Logistic regression analysis was used for the multivariate analysis, the area under curve >0.75 stands for acceptable predicting accuracy.

Results: Non-selective consecutive data with a total of 4,936 primary breast cancer cases treated from Oct. 2010 to Apr. 2016 was extracted from the prospective database. Exclusion criteria: Pathologically diagnosed by surgical resection (n=492); carcinoma in situ (n=145); abnormal ALN by ultrasound underwent fine needle aspiration (FNA) or CNB (n= 750); systemic treatment prior to SLNB (n=349); no SLN detected after injection (n=81); male (n=4). A total of 3,115 cases met the inclusion criteria. Among which 2,317 (74.3%) cases were negative SLN pathology and 798 (25.7%) cases were positive SLN pathology. The main findings of this study were that the univariate analysis such as, patients' age, menstruation, tumor size, ER/PR, HER-2 were influencial factors, p<0.05. Multivariate analysis showed that the area under the ROC curve was 0.658(95% CI 0.637-0.679), indicating that the combination of all the clinic-pathologic factors with ultrasound could not stand for acceptable predicting accuracy.

Conclusion: Ultrasound together with clinical indexes cannot predict SLN metastasis for ultrasound-ALN-negative breast cancer patients.

The result of univariates related to SLNItemsSLN-Negative%(n)SLN-Positive%(n)p valueAge≤4070.5(324)29.5(136)0.036>4075.1(1,993)24.9(662)Premenopausal71.8(1,215)28.2(477)<0.001Postmenopausal77.4(1,102)22.6(321)T size(cm)≤278.4(1,242)21.6(342)<0.001T size(cm)>270.2(1,075)29.8(456)IDC I83.0(455)17.0(93)<0.001IDC II+III71.1(1,603)28.8(649)Other pathology types82.2(259)17.8(56)ER≤10%85.8(652)14.2(108)<0.001ER>10%70.7(1,665)29.3(690)PR≤10%80.3(851)19.7(208)<0.001PR>10%71.3(1,466)28.7(590) HER-2 0,1+,2+&FISH-73.1(1,729)26.9(635)0.008HER-2 3+,2++78.3(588)21.7(163) 

Citation Format: Chen X, He Y, Huo L, Li J, Xie Y, Wang T, Fan Z, Ouyang T. Ultrasound together with clinical indexes cannot predict sentinel lymph node metastasis for ultrasound-axillary lymph node-negative breast cancer patients [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 PD2-01.

Carotid Artery Wall Imaging: Perspective and Guidelines from the ASNR Vessel Wall Imaging Study Group and Expert Consensus Recommendations of the American Society of Neuroradiology

Identification of carotid artery atherosclerosis is conventionally based on measurements of luminal stenosis and surface irregularities using in vivo imaging techniques including sonography, CT and MR angiography, and digital subtraction angiography. However, histopathologic studies demonstrate considerable differences between plaques with identical degrees of stenosis and indicate that certain plaque features are associated with increased risk for ischemic events. The ability to look beyond the lumen using highly developed vessel wall imaging methods to identify plaque vulnerable to disruption has prompted an active debate as to whether a paradigm shift is needed to move away from relying on measurements of luminal stenosis for gauging the risk of ischemic injury. Further evaluation in randomized clinical trials will help to better define the exact role of plaque imaging in clinical decision-making. However, current carotid vessel wall imaging techniques can be informative. The goal of this article is to present the perspective of the ASNR Vessel Wall Imaging Study Group as it relates to the current status of arterial wall imaging in carotid artery disease.

1 Microinjection of CPE-Binding Protein Polyadenylated mRNA Increases Developmental Competence of Bovine Oocytes In Vitro

Developmental competence is acquired during oocyte growth and maturation while oocytes undergo both nuclear and cytoplasmic changes. Completion of oocyte maturation and subsequent embryo development relies mostly on maternally synthesised and stored mRNAs at the transcriptionally quiescent phase. The temporal and spatial post-transcriptional and translational regulation of the stored mRNA in mammalian oocyte cytoplasm is essential for developmental competence of oocytes and is often controlled via cytoplasmic polyadenylation. Cytoplasmic polyadenylation element (CPE)-binding protein (CPEB) is required for polyadenylation of most mRNAs during oocyte maturation. It has been reported that in vitro-matured oocytes with high developmental competence showed an increased level of CPEB mRNA in oocyte cytoplasm. Thus, we hypothesise that the introduction of exogenous CPEB mRNA into in vitro-matured oocytes could increase their developmental capability. In this study, we first synthesised polyadenylated CPEB mRNAs by in vitro transcription. Cumulus-oocyte complexes were recovered from slaughterhouse ovaries and subjected to in vitro maturation for 21 h. After the removal of cumulus cells, matured oocytes were parthenogenetically activated (5 min in 5 mM ionomycin followed by 4 h in 2 mM DMAP with 5 mg mL−1 cycloheximide). Each activated oocyte was injected with 5 to 10 pL of poly(A)-RNA solution (400 ng μL−1; CPEB mRNA and green fluorescent protein (GFP) mRNA for the injection group or GFP mRNA for the control group) using a micromanipulator. After injection, the oocytes were cultured in SOF medium supplemented with amino acids for 8 days. No difference was observed in cleavage rate between CPEB and control group. However, the blastocyst rate was significantly higher in the CPEB group than in the control (24.9 ± 2.9% v. 15.0 ± 4.5%; P < 0.05). Cleavage and blastocyst rates were analysed by one-way ANOVA. We also compared the gene expression profile of blastocysts derived from both groups. The blastocysts were collected individually and analysed by single-embryo RT-PCR. Twenty-two genes were selected for analysis based on their roles in genomic reprogramming and embryonic development and fell into 6 functional categories: growth regulatory factors, cell cycle regulation, imprinting, apoptosis, pluripotency and DNA methyltransferase. The single-embryo RT-PCR was performed using the Flex-Six integrated fluidic chip (Fluidigm Corp., South San Francsisco, CA, USA) on the BioMark platform (Fluidigm Corp.). Relative expression values were calculated using the ΔΔCT (fold change) method and analysed by ANOVA. We found that 6 genes (H19, GRB10, DNMT1, CCNB1, CDK2, and SOX2) were up-regulated and 3 were down-regulated (DNMT2, BAX, and P53), along with the overexpression of CPEB gene (P < 0.05). Our results demonstrate that developmental competence can be improved by injecting exogenous CPEB mRNA into in vitro-matured metaphase II cattle oocytes, which reaffirms the essential role of CPEB in early embryonic development.

28 Generation of Immunoglobulin Heavy Constant Mu (IGHM) Knockout Goats Using CRISPR/Cas9 and Somatic Cell Nuclear Transfer

Towards the goals of inactivating endogenous goat immunoglobulin (Ig) genes and producing fully human polyclonal antibodies in transchromosomal goats carrying a human artificial chromosome comprising the entire human Ig gene repertoire, we report here the successful generation of IgM heavy chain knockout (IGHM−/−) goats using CRISPR/Cas9 and somatic cell nuclear transfer (SCNT) techniques. Two single-guide RNAs (sgRNAs) were designed specific for exon 1 of the goat IGHM constant region (GenBank: EU182621.1). The gene-targeting vectors were constructed by using pX330 plasmid (Plasmid No. 42230, Addgene, Cambridge, MA, USA) and transfected into 2 × 105 goat fetal fibroblast cells. Gene-targeting efficiency of each targeting vector was determined by PCR-restriction fragment length polymorphism (RFLP) assay 3 days post-transfection. Our results showed that one of the sgRNAs, 5′-GAAAGGCGCTTGAGGAATGC-3′, was efficient in directing Cas9 to generate targeted cleavages in exon 1 of IGHM constant region, with a mutation efficiency of 20%. We established single cell-derived fetal fibroblast colonies by limiting dilution of the cells transfected with the targeting vector. Colony screening with the PCR-RFLP assay confirmed that we achieved targeted gene disruption in exon 1 in 11/49 (22.4%) of the colonies (7 colonies with biallelic and 4 with monoallelic gene disruption). Sanger sequencing analysis of genomic DNA isolated from cell colonies with biallelic mutations showed that typical nucleotide deletions and insertions (indels), caused by repairing double-strand DNA breaks during the error-prone non-homologous end joining (NHEJ) process, were generated at the targeting site of exon 1. One of the colonies harboring a 1-nucleotide (nt) deletion was used as nuclear donors for SCNT. A total of 102 1-cell-stage cloned embryos were generated and surgically transferred into 6 synchronized recipients. Three of the recipients (3/6, 50.0%) were confirmed pregnant by ultrasonography on Day 40 to 45 of gestation. Two pregnancies were sacrificed for IGHM−/− fetal fibroblast isolation and one pregnancy was allowed to go to term, which led to the birth of a live and seemingly healthy kid. This goat was reared conventionally and appeared healthy until 5 weeks of age when it was killed because of commensal virus infection. The PCR-RFLP assay and sequence analysis showed that this cloned goat carried a biallelic 1-nt deletion in exon 1 of IGHM, which was identical to the donor colony it was originated from. No lymphoid follicles were observed in lymph nodes and spleen by histology, and immunohistochemistry for B cells (CD20) and T cells (CD3) demonstrated a lack of B cells in lymph nodes and spleen but the presence of T cells, confirming that IGHM has been successfully knocked out.

RNA-sequencing study of peripheral blood mononuclear cells in sporadic Ménière's disease patients: possible contribution of immunologic dysfunction to the development of this disorder

To date, the pathogenesis of Ménière's disease (MD) remains unclear. This study aims to investigate the possible relationship between potential immune system-related genes and sporadic MD. The whole RNA-sequencing (RNA-seq) technology was used to analyse the transcriptome of peripheral blood mononuclear cells of three MD patients and three control individuals. Of 366 differentially expressed genes (DEGs), 154 genes were up-regulated and 212 genes were down-regulated (|log₂ fold change| > 1 and P < 0·05). Gene ontology (GO) enrichment analysis illustrated that immune relevant factors played a key role in the pathogenesis of MD. Of 366 DEGs, we focused upon analysing the possible immune-related genes, among which the significantly up-regulated genes [glutathione S-transferase mu 1 (GSTM1), transmembrane protein 176 (TMEM176)B, TMEM176A] and down-regulated genes [solute carrier family 4 member (SLC4A)10 and SLC4A1] especially drew our attention. The mRNA expression levels of GSTM1, TMEM176B, TMEM176A, SLC4A1 and SLC4A10 were analysed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The serum concentration of GSTM1, TMEM176B and SLC4A10 proteins were measured by enzyme-linked immunosorbent assay (ELISA). Considering the results of qRT-PCR and ELISA, it was noteworthy that GSTM1 exhibited the highest fold change between two groups, which was consistent with the deep sequencing results by RNA-seq. In conclusion, our study first offers a new perspective in MD development on the basis of RNA expression patterns, suggesting that immune factors might be involved in the MD pathogenesis. Remarkably, GSTM1 might be a possible candidate gene for the diagnostic biomarker of MD and provides the basis for further biological and functional investigations.

Substitutional carbon doping of free-standing and Ru-supported BN sheets: a first-principles study

The development of spatially homogeneous mixed structures with boron (B), nitrogen (N) and carbon (C) atoms arranged in a honeycomb lattice is highly desirable, as they open the possibility of creating stable two-dimensional materials with tunable band gaps. However, at least in the free-standing form, the mixed BCN system is energetically driven towards phase segregation to graphene and hexagonal BN. It is possible to overcome the segregation when BCN material is grown on a particular metal substrate, for example Ru(0 0 0 1), but the stabilization mechanism is still unknown. With the use of density-functional theory we study the energetics of BN/Ru slabs, with different types of configurations of C substitutional defects introduced to the h-BN overlayer. The results are compared to the energetics of free-standing BCN materials. We found that the substrate facilitates the C substitution process in the h-BN overlayer. Thus, more homogeneous BCN material can be grown, overcoming the segregation into graphene and h-BN. In addition, we investigate the electronic and transport gaps in free-standing BCN structures, and assess their mechanical properties and stability. The band gap in mixed BCN free-standing material depends on the concentration of the constituent elements and ranges from zero in pristine graphene to nearly 5 eV in free-standing h-BN. This makes BCN attractive for application in modern electronics.

Nrf2-Keap1 pathway promotes cell proliferation and diminishes ferroptosis

Cancer cells are hallmarked by high proliferation and imbalanced redox consumption and signaling. Various oncogenic pathways such as proliferation and evading cell death converge on redox-dependent signaling processes. Nrf2 is a key regulator in these redox-dependent events and operates in cytoprotection, drug metabolism and malignant progression in cancer cells. Here, we show that patients with primary malignant brain tumors (glioblastomas, WHO °IV gliomas, GBM) have a devastating outcome and overall reduced survival when Nrf2 levels are upregulated. Nrf2 overexpression or Keap1 knockdown in glioma cells accelerate proliferation and oncogenic transformation. Further, activation of the Nrf2-Keap1 signaling upregulates xCT (aka SLC7A11 or system X_c⁻) and amplifies glutamate secretion thereby impacting on the tumor microenvironment. Moreover, both fostered Nrf2 expression and conversely Keap1 inhibition promote resistance to ferroptosis. Altogether, the Nrf2-Keap1 pathway operates as a switch for malignancy in gliomas promoting cell proliferation and resistance to cell death processes such as ferroptosis. Our data demonstrate that the Nrf2-Keap1 pathway is critical for cancer cell growth and operates on xCT. Nrf2 presents the Achilles’ heel of cancer cells and thus provides a valid therapeutic target for sensitizing cancer for chemotherapeutics.

CT coronary angiography findings in non-atherosclerotic coronary artery diseases

Non-atherosclerotic coronary artery diseases are being increasingly recognised as causes of acute coronary events. Invasive coronary angiography frequently fails to identify the abnormalities in the proximal course of coronary arteries and coronary wall, while computed tomography coronary angiography (CTCA) allows for acquisition of more detailed information. CTCA serves as a reliable method for evaluating patients with non-atherosclerotic coronary artery diseases. The purpose of this article is to provide an overview of non-atherosclerotic abnormalities that may be demonstrated on CTCA.

L-Tetrahydropalmatine Induces Apoptosis in EU-4 Leukemia Cells by Down-Regulating X-Linked Inhibitor of Apoptosis Protein and Increases the Sensitivity Towards Doxorubicin

BACKGROUND

L-Tetrahydropalmatine (L-THP) is a tetra-hydro protoberberine isoquinoline alkaloid. The phyto-compounds bearing isoquinoline alkaloids have been reported to show a potential effect against a number of human cancers cell lines including leukemia. We hypothesized that L-THP, being an isoquinoline alkaloid, could be a potential molecule against acute lymphoblastic leukemia (ALL), in this study, we evaluate L-THP against p53 deficient leukemia EU-4 cell lines in vitro.

METHODS

For the study, p53 null leukemia EU-4 cells were used and treated with LTHP. The extent of apoptosis and viability of cells were determined. Expression of apoptosis related proteins such as XIAP and MDM2 was done by western blot and PCR studies. The expression of MDM2 and XIAP was knocked down by small interfering RNA (siRNA).

RESULTS

Outcomes of the study suggested that L-THP caused p53-indipendent apoptosis mediated by XIAP in EU-4 cells. The treatment of L-THP caused a decrease in the levels of XIAP protein with increasing dose and time. L-THP caused down-regulation of XIAP protein via inhibiting the expression of MDM2 and involving proteasomedependent pathway. Also, the outcomes of experiments suggested increased sensitivity of leukemia cells towards doxorubicin due to the inhibition of XIAP by L-THP or by siRNA.

CONCLUSION

Findings of the study confirm that L-THP resulted in p53 independent apoptosis via down-regulating XIAP protein by inhibiting MDM2 associated with proteasome-dependent pathway and increased sensitivity of EU-4 cells against doxorubicin. L-THP caused activation of caspase and resulted in apoptosis, L-THP may be a novel molecule for inducing apoptosis specifically in p53 null leukemia EU-4 cells.

A class of circadian long non-coding RNAs mark enhancers modulating long-range circadian gene regulation

Circadian rhythm exerts its influence on animal physiology and behavior by regulating gene expression at various levels. Here we systematically explored circadian long non-coding RNAs (lncRNAs) in mouse liver and examined their circadian regulation. We found that a significant proportion of circadian lncRNAs are expressed at enhancer regions, mostly bound by two key circadian transcription factors, BMAL1 and REV-ERBα. These circadian lncRNAs showed similar circadian phases with their nearby genes. The extent of their nuclear localization is higher than protein coding genes but less than enhancer RNAs. The association between enhancer and circadian lncRNAs is also observed in tissues other than liver. Comparative analysis between mouse and rat circadian liver transcriptomes showed that circadian transcription at lncRNA loci tends to be conserved despite of low sequence conservation of lncRNAs. One such circadian lncRNA termed lnc-Crot led us to identify a super-enhancer region interacting with a cluster of genes involved in circadian regulation of metabolism through long-range interactions. Further experiments showed that lnc-Crot locus has enhancer function independent of lnc-Crot's transcription. Our results suggest that the enhancer-associated circadian lncRNAs mark the genomic loci modulating long-range circadian gene regulation and shed new lights on the evolutionary origin of lncRNAs.

ATF4 promotes angiogenesis and neuronal cell death and confers ferroptosis in a xCT-dependent manner

Activating transcription factor 4 (ATF4) is a critical mediator of metabolic and oxidative homeostasis and cell survival. ATF4 is elevated in response to diverse microenvironmental stresses, including starvation, ER stress damages and exposure to toxic factors. Here we show that ATF4 expression fosters the malignancy of primary brain tumors (WHO grade III and IV gliomas) and increases proliferation and tumor angiogenesis. Hence, ATF4 expression promotes cell migration and anchorage-independent cell growth, whereas siRNA-mediated knockdown of ATF4 attenuates these features of malignancy in human gliomas. Further experiments revealed that ATF4-dependent tumor promoting effects are mediated by transcriptional targeting the glutamate antiporter xCT/SCL7A11 (also known as system Xc^-). Thus, xCT is elevated as a consequence of ATF4 activation. We further found evidence that ATF4-induced proliferation can be attenuated by pharmacological or genetic xCT inhibition and ferroptosis inducers such as sorafenib, erastin and GPx4 inhibitor RSL3. Further, fostered xCT expression promotes cell survival and growth in ATF4 knockdown cells. Moreover, increased xCT levels ameliorate sorafenib and erastin-induced ferroptosis. Conversely, ATF4 knockdown renders cells susceptible for erastin, sorafenib and RSL3-induced ferroptosis. We further identified that ATF4 promotes tumor-mediated neuronal cell death which can be alleviated by xCT inhibition. Moreover, elevated ATF4 expression in gliomas promotes tumor angiogenesis. Noteworthy, ATF4-induced angiogenesis could be diminished by ferroptosis inducers erastin and by GPx4 inhibitor RSL3. Our data provide proof-of-principle evidence that ATF4 fosters proliferation and induces a toxic microenvironmental niche. Furthermore, ATF4 increases tumor angiogenesis and shapes the vascular architecture in a xCT-dependent manner. Thus, inhibition of ATF4 is a valid target for diminishing tumor growth and vasculature via sensitizing tumor cells for ferroptosis.

Neutron Generation by Laser-Driven Spherically Convergent Plasma Fusion

We investigate a new laser-driven spherically convergent plasma fusion scheme (SCPF) that can produce thermonuclear neutrons stably and efficiently. In the SCPF scheme, laser beams of nanosecond pulse duration and 10^{14}-10^{15}  W/cm^{2} intensity uniformly irradiate the fuel layer lined inside a spherical hohlraum. The fuel layer is ablated and heated to expand inwards. Eventually, the hot fuel plasmas converge, collide, merge, and stagnate at the central region, converting most of their kinetic energy to internal energy, forming a thermonuclear fusion fireball. With the assumptions of steady ablation and adiabatic expansion, we theoretically predict the neutron yield Y_{n} to be related to the laser energy E_{L}, the hohlraum radius R_{h}, and the pulse duration τ through a scaling law of Y_{n}∝(E_{L}/R_{h}^{1.2}τ^{0.2})^{2.5}. We have done experiments at the ShengGuangIII-prototype facility to demonstrate the principle of the SCPF scheme. Some important implications are discussed.