Omics-Based Mathematical Modeling Unveils Pathogenesis of Periodontitis in an Experimental Murine Model

Periodontitis is a multifactorial disease that progresses via dynamic interaction between bacterial and host-derived genetic factors. The recent trend of omics analyses has discovered many periodontitis-related risk factors. However, how much the individual factor affects the pathogenesis of periodontitis is still unknown. This article aims to identify multiple key factors related to the pathogenesis of periodontitis and quantitatively predict the influence of each factor on alveolar bone resorption by omics analysis and mathematical modeling. First, we induced periodontitis in mice (n = 3 or 4 at each time point) by tooth ligation. Next, we assessed alveolar bone resorption by micro-computed tomography, alterations in the gene expression by RNA sequencing, and the microbiome of the gingivae by 16S ribosomal RNA sequencing during disease pathogenesis. Omics data analysis identified key players (bacteria and molecules) involved in the pathogenesis of periodontitis. We then constructed a mathematical model of the pathogenesis of periodontitis by employing ordinary differential equations that described the dynamic regulatory interplay between the key players and predicted the alveolar bone integrity as output. Finally, we estimated the model parameters using our dynamic experimental data and validated the model prediction of influence on alveolar bone resorption by in vivo experiments. The model predictions and experimental results revealed that monocyte recruitment induced by bacteria-mediated Toll-like receptor activation was the principal reaction regulating alveolar bone resorption in a periodontitis condition. On the other hand, osteoblast-mediated osteoclast differentiation had less impact on bone integrity in a periodontitis condition.

Signature of spin-phonon coupling driven charge density wave in a kagome magnet

The intertwining between spin, charge, and lattice degrees of freedom can give rise to unusual macroscopic quantum states, including high-temperature superconductivity and quantum anomalous Hall effects. Recently, a charge density wave (CDW) has been observed in the kagome antiferromagnet FeGe, indicative of possible intertwining physics. An outstanding question is that whether magnetic correlation is fundamental for the spontaneous spatial symmetry breaking orders. Here, utilizing elastic and high-resolution inelastic x-ray scattering, we observe a c-axis superlattice vector that coexists with the 2[Formula: see text]2[Formula: see text]1 CDW vectors in the kagome plane. Most interestingly, between the magnetic and CDW transition temperatures, the phonon dynamical structure factor shows a giant phonon-energy hardening and a substantial phonon linewidth broadening near the c-axis wavevectors, both signaling the spin-phonon coupling. By first principles and model calculations, we show that both the static spin polarization and dynamic spin excitations intertwine with the phonon to drive the spatial symmetry breaking in FeGe.

Clinical trial on the efficacy and safety of NPC-15 for patients with xeroderma pigmentosum exaggerated sunburn reaction type: XP-1 study protocol for a multicentre, double-blinded, placebo-controlled, two-group crossover study followed by a long-term open study in Japan

INTRODUCTION

Xeroderma pigmentosum (XP) is a rare intractable disease without a fundamental treatment, presenting with severe photosensitivity, freckle-like pigmented and depigmented maculae and numerous skin cancers before the age of 10 years without strict sun protection. About 70% of the patients exhibit extremely severe sunburn reactions and most of them develop neurological symptoms, including sensorineural hearing impairment and progressive peripheral and central nervous disorders beginning from childhood ages. In the preclinical study, we found that N-acetyl-5-methoxytryptamine was effective in suppressing skin tumour development in addition to improvement of auditory brainstem response in chronically ultraviolet-irradiated XP-A model mice.

METHODS AND ANALYSIS

On the bases of the preclinical study, we conduct a clinical trial on the efficacy of NPC-15 for patients with XP with exaggerated sunburn reaction type by a multicentre, double-blinded placebo-controlled, two-group crossover study followed by a 52 weeks open study.

ETHICS AND DISSEMINATION

Ethics approval is overseen by the Kobe University Institutional Review Board and Osaka Medical and Pharmaceutical University Institutional Review Board, and the study is conducted in accordance with the approved protocol. All participants will be required to provide written informed consent. Findings will be disseminated through scientific and professional conferences and peer-reviewed journal publications. The data sets generated during the study will be available from the corresponding author on reasonable request.

TRIAL REGISTRATION NUMBER

jRCTs051210181.

Oxidative Stress Inhibits Endotoxin Tolerance and May Affect Periodontitis

Periodontal disease is caused by dysbiosis of the dental biofilm and the host inflammatory response. Various pathogenic factors, such as proteases and lipopolysaccharides (LPSs) produced by bacteria, are involved in disease progression. Endotoxin tolerance is a function of myeloid cells, which sustain inflammation and promote tissue regeneration upon prolonged stimulation by endotoxins such as LPS. The role of endotoxin tolerance is gaining attention in various chronic inflammatory diseases, but its role in periodontal disease remains elusive. Oxidative stress, one of the major risk factors for periodontal disease, promotes disease progression through various mechanisms, of which only some are known. The effect of oxidative stress on endotoxin tolerance has not yet been studied, and we postulated that endotoxin tolerance regulation may be an additional mechanism through which oxidative stress influences periodontal disease. This study aimed to reveal the effect of oxidative stress on endotoxin tolerance and that of endotoxin tolerance on periodontitis progression. The effect of oxidative stress on endotoxin tolerance was analyzed in vitro using peritoneal macrophages of mice and hydrogen peroxide (H₂O₂). The results showed that oxidative stress inhibits endotoxin tolerance induced by Porphyromonas gingivalis LPS in macrophages, at least partially, by downregulating LPS-elicited negative regulators of Toll-like receptor (TLR) signaling. A novel oxidative stress mouse model was established using SMP30KO mice incapable of ascorbate biosynthesis. Using this model, we revealed that oxidative stress impairs endotoxin tolerance potential in macrophages in vivo. Furthermore, gingival expression of endotoxin tolerance-related genes and TLR signaling negative regulators was decreased, and symptoms of ligature-induced periodontitis were aggravated in the oxidative stress mouse model. Our findings suggest that oxidative stress may contribute to periodontitis progression through endotoxin tolerance inhibition.

Matrix Vesicle-Mediated Mineralization and Potential Applications

Hard tissues, including the bones and teeth, are a fundamental part of the body, and their formation and homeostasis are critically regulated by matrix vesicle-mediated mineralization. Matrix vesicles have been studied for 50 y since they were first observed using electron microscopy. However, research progress has been hampered by various technical barriers. Recently, there have been great advancements in our understanding of the intracellular biosynthesis of matrix vesicles. Mitochondria and lysosomes are now considered key players in matrix vesicle formation. The involvement of mitophagy, mitochondrial-derived vesicles, and mitochondria-lysosome interaction have been suggested as potential detailed mechanisms of the intracellular pathway of matrix vesicles. Their main secretion pathway may be exocytosis, in addition to the traditionally understood mechanism of budding from the outer plasma membrane. This basic knowledge of matrix vesicles should be strengthened by novel nano-level microscopic technologies, together with basic cell biologies, such as autophagy and interorganelle interactions. In the field of tissue regeneration, extracellular vesicles such as exosomes are gaining interest as promising tools in cell-free bone and periodontal regenerative therapy. Matrix vesicles, which are recognized as a special type of extracellular vesicles, could be another potential alternative. In this review, we outline the recent significant progress in the process of matrix vesicle-mediated mineralization and the potential clinical applications of matrix vesicles for tissue regeneration.

Outcomes with durvalumab after chemoradiotherapy in stage IIIA-N2 non-small-cell lung cancer: an exploratory analysis from the PACIFIC trial

Background

The phase III PACIFIC trial (NCT02125461) established consolidation durvalumab as standard of care for patients with unresectable, stage III non-small-cell lung cancer (NSCLC) and no disease progression following chemoradiotherapy (CRT). In some cases, patients with stage IIIA-N2 NSCLC are considered operable, but the relative benefit of surgery is unclear. We report a post hoc, exploratory analysis of clinical outcomes in the PACIFIC trial, in patients with or without stage IIIA-N2 NSCLC.

Materials and methods

Patients with unresectable, stage III NSCLC and no disease progression after ≥2 cycles of platinum-based, concurrent CRT were randomized 2 : 1 to receive durvalumab (10 mg/kg intravenously; once every 2 weeks for up to 12 months) or placebo, 1-42 days after CRT. The primary endpoints were progression-free survival (PFS; assessed by blinded independent central review according to RECIST version 1.1) and overall survival (OS). Treatment effects within subgroups were estimated by hazard ratios (HRs) from unstratified Cox proportional hazards models.

Results

Of 713 randomized patients, 287 (40%) had stage IIIA-N2 disease. Baseline characteristics were similar between patients with and without stage IIIA-N2 NSCLC. With a median follow-up of 14.5 months (range: 0.2-29.9 months), PFS was improved with durvalumab versus placebo in both patients with [HR = 0.46; 95% confidence interval (CI), 0.33-0.65] and without (HR = 0.62; 95% CI 0.48-0.80) stage IIIA-N2 disease. Similarly, with a median follow-up of 25.2 months (range: 0.2-43.1 months), OS was improved with durvalumab versus placebo in patients with (HR = 0.56; 95% CI 0.39-0.79) or without (HR = 0.78; 95% CI 0.57-1.06) stage IIIA-N2 disease. Durvalumab had a manageable safety profile irrespective of stage IIIA-N2 status.

Conclusions

Consistent with the intent-to-treat population, treatment benefits with durvalumab were confirmed in patients with stage IIIA-N2, unresectable NSCLC. Prospective studies are needed to determine the optimal treatment approach for patients who are deemed operable.

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The PACIFIC trial established durvalumab after CRT as standard of care for unresectable, stage III NSCLC.

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The optimum multimodal treatment strategy for patients with potentially resectable, stage IIIA-N2 NSCLC is unknown.

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Survival benefit with durvalumab was observed in patients with stage IIIA-N2, unresectable NSCLC in this post hoc analysis.

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Durvalumab after CRT also exhibited a manageable safety profile in this subpopulation from PACIFIC.

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Studies of surgical vs. non-surgical strategies are needed to establish the best approach for potentially operable patients.

A randomized crossover pilot study comparing the efficacy of an auto-demand oxygen delivery system with that of a conventional demand oxygen delivery system in patients with chronic respiratory failure

INTRODUCTION

: When using portable oxygen, a demand oxygen delivery system (DODS), which senses the beginning of inhalation and delivers a bolus of oxygen, is often used. However, conventional DODS may not supply sufficient oxygen when reduced tidal flow fails to trigger the flow sensor. Recently, "auto-DODS," which detects the negative pressure of inhalation and switches among 3 trigger sensitivity levels (standard, high, and extra high), has been developed to improve the efficacy of oxygenation. An auto-DODS can also supply pulsed-flow oxygen when it detects apnea, whereas a conventional DODS has only standard sensitivity. This randomized, open-label, crossover pilot study compared the performance of an auto-DODS with that of a conventional DODS.

METHODS

: We recruited patients with chronic obstructive pulmonary disease (COPD) or interstitial pneumonia receiving long-term oxygen therapy. Interventions were performed on 2 different days for each participant. On each day, an auto-DODS or a conventional DODS were tested at rest for 30 minutes and during the 6-minute walk test. The primary outcome was mean oxygen saturation (SpO2). Secondary outcomes were the ratios of time for each sensitivity level and pulsed-flow oxygen when using the auto-DODS, total time desaturated below SpO2 90%, percentage of time desaturated below SpO2 90%, minimum SpO2, mean and maximum pulse rate, six-minute walk distance, recovery time after 6-minute walk test, modified Borg scale, comfort, and discomfort index.

RESULTS

: When using the auto-DODS at rest, a high or extra high sensitivity level was observed in addition to standard sensitivity in 6 of 8 participants. During the 6-minute walk test, only standard sensitivity was observed in 6 participants. Mean SpO2 differences between the auto-DODS and conventional DODS at rest and during the 6-minute walk test were -0.6 [-4.5, 3.4] and 0.0 [-2.5, 2.5] ([95% confidence interval]), respectively, neither of which were significant (P = .73 and P = .99). There were no significant differences in secondary outcomes. There were no adverse events when using the auto-DODS.

CONCLUSIONS

: This study showed that the auto-DODS did not show superiority in oxygenation either at rest or during exercise compared to a conventional DODS. The auto-DODS was shown to supply oxygen safely and detect inhalations with various trigger sensitivities.

Giant phonon anomalies in the proximate Kitaev quantum spin liquid α-RuCl3

The Kitaev quantum spin liquid epitomizes an entangled topological state, for which two flavors of fractionalized low-energy excitations are predicted: the itinerant Majorana fermion and the Z2 gauge flux. It was proposed recently that fingerprints of fractional excitations are encoded in the phonon spectra of Kitaev quantum spin liquids through a novel fractional-excitation-phonon coupling. Here, we detect anomalous phonon effects in α-RuCl3 using inelastic X-ray scattering with meV resolution. At high temperature, we discover interlaced optical phonons intercepting a transverse acoustic phonon between 3 and 7 meV. Upon decreasing temperature, the optical phonons display a large intensity enhancement near the Kitaev energy, JK~8 meV, that coincides with a giant acoustic phonon softening near the Z2 gauge flux energy scale. These phonon anomalies signify the coupling of phonon and Kitaev magnetic excitations in α-RuCl3 and demonstrates a proof-of-principle method to detect anomalous excitations in topological quantum materials.

Increased oxygen uptake and utilization in the peripheral muscles, rather than cardiac function reserve, may be determinants of increased peak VO2 by cardiac rehabilitation in heart failure

Background

Peak oxygen consumption (peak VO2) is a major prognostic parameter in heart failure (HF). Previous studies have shown a relationship between peak VO2 and impaired oxygen uptake and utilization in the peripheral muscles. The purpose of this study was to clarify the determinant of increased peak VO2 by cardiac rehabilitation (CR) in patients with HF.

Methods

We performed echocardiography during upright ramp bicycle cardiopulmonary exercise test in 30 HF patients (61±1 years of age, 80% male) before and 6 months after CR. HR reserve was determined as the change in HR from rest to peak exercise, expressed as a percentage of the predicted maximal HR reserve. Elastance index (EAI) and LV end-systolic elastance index (ELVI) were derived as the ratio of end-systolic pressure to stroke volume index and end-systolic volume index, respectively. End-systolic pressure was estimated from the equation 0.9 × brachial systolic blood pressure. Ventriculo-arterial coupling (VAC) was calculated as the quotient of EAI and ELVI. The ratio of LDEDVI to E/e' mean was used to evaluate LV diastolic compliance. Systemic vascular resistance index was calculated as mean arterial pressure divided by echocardiography calculated cardiac index and multiplied by 80. The arterial venous oxygen content difference (C (A-V) O2 gradient) was calculated by using the Fick equation as: VO2/echocardiography calculated cardiac output.

Results

Peak VO2 and C (A-V) O2 gradient were increased by CR. However, heart rate reserve, systolic reserve, VAC, diastolic reserve and vasodilation reserve were unchanged by CR (Table 1).

Conclusions

Increased oxygen uptake and utilization in the peripheral muscles, rather than cardiac function reserve, may be determinants of increased peak VO2 by CR in HF.

Table 1

Funding Acknowledgement

Type of funding source: None

Effect of aerobic exercise on muscle structure and expression of proteins promoting hypertrophy and metabolism in aged rats

Aging and physical inactivity lead to histochemical changes in muscles. The expression of many muscle proteins, including brain-derived neurotrophic factor (BDNF), silent information regulator of transcription 1 (SIRT1), and peroxisome proliferator-activated receptor γγ coactivator-1α (PGC-1a), declines with age. However, the effect of aerobic exercise on muscle structure and the expression profile of these proteins in elderly rats is unknown. Here, we investigated whether short-term aerobic exercise improves muscle structure and increases BDNF, SIRT1, and PGC-1a levels in aged rats. Ten male Wistar rats (95-week-old) were assigned to sedentary (SED) or exercise (Ex) groups. The Ex group performed running on a treadmill for 1 h, 6 times per week, for 2 weeks. The extensor digitorum longus muscles were removed to examine the muscle fibre type composition, cross-sectional area, and capillary-to-fibre (C/F) ratio. BDNF, SIRT1, and PGC-1a levels were evaluated by western blotting. Relative to the SED group, the Ex group showed increased proportion of Type I fibres (P<0.05), cross-sectional area of all muscle fibre types (P<0.05), succinate dehydrogenase activity (P<0.001), C/F ratio (P<0.05), and expression of BDNF, SIRT1, and PGC-1a (P<0.05).Thus, 2 weeks of aerobic exercise is sufficient to improve muscle histology and hypertrophic marker protein expression, indicating that it could prevent skeletal muscle atrophy in elderly rats.

Total tumour volume as a prognostic factor in patients with resectable colorectal cancer liver metastases

Background

Although total tumour volume (TTV) may have prognostic value for hepatic resection in certain solid cancers, its importance in colorectal liver metastases (CRLM) remains unexplored. This study investigated its prognostic value in patients with resectable CRLM.

Method

This was a retrospective review of patients who underwent hepatic resection for CRLM between 2008 and 2017 in a single institution. TTV was measured from CT images using three‐dimensional construction software; cut‐off values were determined using receiver operating characteristic (ROC) curve analyses. Potential prognostic factors, overall survival (OS) and recurrence‐free survival (RFS) were determined using multivariable and Kaplan–Meier analyses.

Results

Some 94 patients were included. TTV cut‐off values for OS and RFS were 100 and 10 ml respectively. Right colonic primary tumours, primary lymph node metastasis and bilobar liver metastasis were included in the multivariable analysis of OS; a TTV of 100 ml or above was independently associated with poorer OS (hazard ratio (HR) 6·34, 95 per cent c.i. 2·08 to 17·90; P = 0·002). Right colonic primary tumours and primary lymph node metastasis were included in the RFS analysis; a TTV of 10 ml or more independently predicted poorer RFS (HR 1·90, 1·12 to 3·57; P = 0·017). The 5‐year OS rate for a TTV of 100 ml or more was 41 per cent, compared with 67 per cent for a TTV below 100 ml (P = 0·006). Corresponding RFS rates with TTV of 10 ml or more, or less than 10 ml, were 14 and 58 per cent respectively (P = 0·009). A TTV of at least 100 ml conferred a higher rate of unresectable initial recurrences (12 of 15, 80 per cent) after initial hepatic resection.

Conclusion

TTV was associated with RFS and OS after initial hepatic resection for CRLM; TTV of 100 ml or above was associated with a higher rate of unresectable recurrence.

Radial Spin Texture in Elemental Tellurium with Chiral Crystal Structure

The chiral crystal is characterized by a lack of mirror symmetry and inversion center, resulting in the inequivalent right- and left-handed structures. In the noncentrosymmetric crystal structure, the spin and momentum of electrons are expected to be locked in the reciprocal space with the help of the spin-orbit interaction. To reveal the spin textures of chiral crystals, we investigate the spin and electronic structure in a p-type semiconductor, elemental tellurium, with the simplest chiral structure by using spin- and angle-resolved photoemission spectroscopy. Our data demonstrate that the highest valence band crossing the Fermi level has a spin component parallel to the electron momentum around the Brillouin zone corners. Significantly, we have also confirmed that the spin polarization is reversed in the crystal with the opposite chirality. The results indicate that the spin textures of the right- and left-handed chiral crystals are hedgehoglike, leading to unconventional magnetoelectric effects and nonreciprocal phenomena.

Outcomes with durvalumab by tumour PD-L1 expression in unresectable, stage III non-small-cell lung cancer in the PACIFIC trial

BACKGROUND

In the PACIFIC trial, durvalumab significantly improved progression-free and overall survival (PFS/OS) versus placebo, with manageable safety, in unresectable, stage III non-small-cell lung cancer (NSCLC) patients without progression after chemoradiotherapy (CRT). We report exploratory analyses of outcomes by tumour cell (TC) programmed death-ligand 1 (PD-L1) expression.

PATIENTS AND METHODS

Patients were randomly assigned (2:1) to intravenous durvalumab 10 mg/kg every 2 weeks or placebo ≤12 months, stratified by age, sex, and smoking history, but not PD-L1 status. Where available, pre-CRT samples were tested for PD-L1 expression (immunohistochemistry) and scored at pre-specified (25%) and post hoc (1%) TC cut-offs. Treatment-effect hazard ratios (HRs) were estimated from unstratified Cox proportional hazards models (Kaplan-Meier-estimated medians).

RESULTS

In total, 713 patients were randomly assigned, 709 of whom received at least 1 dose of study treatment durvalumab (n = 473) or placebo (n = 236). Some 451 (63%) were PD-L1-assessable: 35%, 65%, 67%, 33%, and 32% had TC ≥25%, <25%, ≥1%, <1%, and 1%-24%, respectively. As of 31 January 2019, median follow-up was 33.3 months. Durvalumab improved PFS versus placebo (primary-analysis data cut-off, 13 February 2017) across all subgroups [HR, 95% confidence interval (CI); medians]: TC ≥25% (0.41, 0.26-0.65; 17.8 versus 3.7 months), <25% (0.59, 0.43-0.82; 16.9 versus 6.9 months), ≥1% (0.46, 0.33-0.64; 17.8 versus 5.6 months), <1% (0.73, 0.48-1.11; 10.7 versus 5.6 months), 1%-24% [0.49, 0.30-0.80; not reached (NR) versus 9.0 months], and unknown (0.59, 0.42-0.83; 14.0 versus 6.4 months). Durvalumab improved OS across most subgroups (31 January 2019 data cut-off; HR, 95% CI; medians): TC ≥ 25% (0.50, 0.30-0.83; NR versus 21.1 months), <25% (0.89, 0.63-1.25; 39.7 versus 37.4 months), ≥1% (0.59, 0.41-0.83; NR versus 29.6 months), 1%-24% (0.67, 0.41-1.10; 43.3 versus 30.5 months), and unknown (0.60, 0.43-0.84; 44.2 versus 23.5 months), but not <1% (1.14, 0.71-1.84; 33.1 versus 45.6 months). Safety was similar across subgroups.

CONCLUSIONS

PFS benefit with durvalumab was observed across all subgroups, and OS benefit across all but TC <1%, for which limitations and wide HR CI preclude robust conclusions.

Isotope Effect on Energy Confinement Time and Thermal Transport in Neutral-Beam-Heated Stellarator-Heliotron Plasmas

The isotope effect on energy confinement time and thermal transport has been investigated for plasmas confined by a stellarator-heliotron magnetic field. This is the first detailed assessment of an isotope effect in a stellarator heliotron. Hydrogen and deuterium plasmas heated by neutral beam injection on the Large Helical Device have exhibited no significant dependence on the isotope mass in thermal energy confinement time, which is not consistent with the simple gyro-Bohm model. A comparison of thermal diffusivity for dimensionally similar hydrogen and deuterium plasmas in terms of the gyroradius, collisionality, and thermal pressure has clearly shown robust confinement improvement in deuterium to compensate for the unfavorable mass dependence predicted by the gyro-Bohm model.

Measurements of radial profile of hydrogen and deuterium density in isotope mixture plasmas using bulk charge exchange spectroscopy

A bulk charge exchange spectroscopy system has been applied to measure the radial profiles of the hydrogen (H) and deuterium (D) density ratio in the isotope mixture plasma in a large helical device. Charge exchange lines of H_α and D_α are fitted by 4 Gaussian of H and D cold components and H and D hot components with 5 parameters by combining the measurement of plasma toroidal rotation velocity with carbon charge exchange spectroscopy. The radial profiles of the relative density of hydrogen and deuterium ions are derived from H and D hot components measured and the beam density calculated from beam attenuation calculation. A proof-of-principle experiment is performed by the H pellet and the D pellet injections into the H-D mixture plasma.

Real-time navigation during hepatectomy using fusion indocyanine green-fluorescence imaging: protocol for a prospective cohort study

INTRODUCTION

In-vivo fluorescence imaging techniques using indocyanine green (ICG) to identify liver tumours and hepatic segment boundaries have been recently developed. The purpose of this study is to evaluate the efficacy of fusion ICG-fluorescence imaging for navigation during hepatectomy.

METHODS AND ANALYSIS

This will be an exploratory single-arm clinical trial; patients with liver tumours will undergo hepatectomy using the ICG-fluorescence imaging system. In total, 110 patients with liver tumours scheduled for elective hepatectomy will be included in this study. Preoperatively, ICG will be intravenously injected at a dose of 0.5 mg/kg body weight within 2 days. To detect liver tumours intraoperatively, the hepatic surface will be initially observed using the ICG-fluorescence imaging system. After identifying and clamping the portal pedicle corresponding to the hepatic segments, including the liver tumours to be resected, additional ICG will be injected intravenously at a dose of 0.5 mg/kg body weight to identify the boundaries of the hepatic segments. The primary outcome measure will be the success or failure of the ICG-fluorescence imaging system in identifying hepatic segments. The secondary outcomes will be the success or failure in identifying liver tumours, liver function indicators, operative time, blood loss, rate of postoperative complications and recurrence-free survival. The findings obtained through this study are expected to help to establish the utility of ICG-fluorescence imaging systems, and therefore contribute to prognostic outcome improvements in patients undergoing hepatectomy for various causes.

ETHICS AND DISSEMINATION

The protocol has been approved by the Kobe University Clinical Research Ethical Committee. The findings of this study will be disseminated widely through peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

UMIN000031054 and jRCT1051180070.

Abstract P5-05-16: Role of estrogen receptor alpha acetylation in estrogen-dependent gene regulation in breast cancers

Estrogens, such as 17β-estradiol (E2), act through estrogen receptor alpha (ERα), a ligand-regulated transcription factor that binds across the genome to promote enhancer formation and regulate gene expression. ERα is expressed in approximately 70% of breast cancers, where it regulates the transcription of genes involved in mitogenic and inflammatory pathways. We are exploring the the acetylation of ERα on lysines 266 and 268, a modification that enhances the DNA binding and transcriptional activities of ERα. ERα acetylation is catalyzed by the lysine acetyltransferases p300 and CBP in an E2- and steroid receptor coregulator (SRC)-dependent manner. Acetylation-dependent activation of ERα has potential implications in breast cancers associated with enhanced coregulator interactions, such as SRC-3/Amplified in Breast (AIB1) gene amplifications and gain-of-function ERα mutations in endocrine resistant metastatic tumors, such as Y537S and D538G. Increased association of ERα with SRCs and p300/CBP leading to enhanced ERα acetylation may promote gain-of-function ERα activity. Our hypothesis is that acetylation of ERα alters its function by increasing E2-responsive gene transcription and signaling in breast cancers. Our current efforts are focused on investigating the role of ERα acetylation on chromatin binding and accessibility, enhancer activity, and target gene transcription. We are using the ER-positive MCF-7 breast cancer cell line with a knockdown/re-expression strategy with biochemical mimics of acetylated (K266/268Q) or unacetylated (K266/268R) ERα. Genomic ERα binding profiles using chromatin immunoprecipitation-sequencing (ChIP-seq) has defined overlapping, but unique, sets of transcriptional targets and recruitment kinetics for the ERα mutants. Current efforts are focused on defining global transcriptional responses associated with the unique binding activities using precision run-on sequencing (PRO-seq). Ultimately, our goal is to define how acetylation affects the binding of ERα to chromatin and its effect on the transcriptional activity of E2-target genes in breast cancers in the context of gain-of-function ERα mutations and coregulator amplifications. Supported in part by a postdoctoral fellowship from the Lalor Foundation to YMV, and grants from the NIDDK, NICHD, and CPRIT to WLK, as well as support from the Cecil H. and Ida Green Center for Reproductive Biology Sciences Endowment.

Citation Format: Vasquez YM, Setlem R, Murakami S, Kraus WL. Role of estrogen receptor alpha acetylation in estrogen-dependent gene regulation in breast cancers [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-05-16.

Development of Co-Culture System of Hepatocytes with Bone Marrow Cells for Expression and Maintenance of Hepatic Functions

In this study, a co-culture system of hepatocytes and bone marrow cells (BMCs) was developed and characterized for the expression and maintenance of ammonia metabolism and albumin secretion activities. A culture medium supplemented with epidermal growth factor, insulin, L-proline, hydrocortisone and 20 % (v/v) heat-inactivated fetal bovine serum was developed. In addition to adhesive bone marrow cells, the co-existence of non-adhesive bone marrow cells was effective in expressing liver-specific functions for at least 3 weeks. On the other hand, experiments with Transwell in which cultured cells were separated by a semi-permeable membrane, suggested that soluble factors secreted by BMCs are the key components in the functional enhancement of cells. Furthermore, direct contact between hepatocytes and BMCs enhanced the formation of spheroids and the expression of liver specific functions. These results indicate that this co-culture system is promising in, for example, bioartificial liver, regenerative medicine, and liver function simulator applications.