Tryptophan extends the life of cytochrome P450

Powerfully oxidizing enzymes need protective mechanisms to prevent self-destruction. The flavocytochrome P450 BM3 from Priestia megaterium (P450BM3) is a self-sufficient monooxygenase that hydroxylates fatty acid substrates using O2 and NADPH as co-substrates. Hydroxylation of long-chain fatty acids (≥C14) is well coupled to O2 and NADPH consumption, but shorter chains (≤C12) are more poorly coupled. Hydroxylation of p-nitrophenoxydodecanoic acid by P450BM3 produces a spectrophotometrically detectable product wherein the coupling of NADPH consumption to product formation is just 10%. Moreover, the rate of NADPH consumption is 1.8 times that of O2 consumption, indicating that an oxidase uncoupling pathway is operative. Measurements of the total number of enzyme turnovers before inactivation (TTN) indicate that higher NADPH concentrations increase TTN. At lower NADPH levels, added ascorbate increases TTN, while a W96H mutation leads to a decrease. The W96 residue is about 7 Å from the P450BM3 heme and serves as a gateway residue in a tryptophan/tyrosine (W/Y) hole transport chain from the heme to a surface tyrosine residue. The data indicate that two oxidase pathways protect the enzyme from damage by intercepting the powerfully oxidizing enzyme intermediate (Compound I) and returning it to its resting state. At high NADPH concentrations, reducing equivalents from the flavoprotein are delivered to Compound I by the usual reductase pathway. When NADPH is not abundant, however, oxidizing equivalents from Compound I can traverse a W/Y chain, arriving at the enzyme surface where they are scavenged by reductants. Ubiquitous tryptophan/tyrosine chains in highly oxidizing enzymes likely perform similar protective functions.

Automatic Treatment Planning for Multi-focal Dynamic Conformal Arc GRID Therapy for Late-Stage Lung Cancer: A Feasibility Study

PURPOSE/OBJECTIVE(S)

Palliative management of large, symptomatic pulmonary lesions, either as primary lung cancers or metastases, can be challenging due to need to balance effective radiation doses for cytoreduction with safety. Spatially Fractionated Radiation Therapy (SFRT), or GRID Therapy, is an emerging technique, which delivers ablative doses of radiotherapy to small, selected areas of tumor, while sparing organs-at-risk (OARs), and has been shown to debulk large lesions in preliminary studies. Conventionally, an alloy GRID block is manufactured to deliver GRID therapy. However, this delivery technique poses a challenge due to need for block, and dosimetrically when the tumor is deep-seated as excess dose may be delivered to OARs, such as skin and chest wall. This study aims to develop a fast, automatic planning solution using multi-focal dynamic conformal arcs (DCA) on modern Linear Accelerator.

MATERIALS/METHODS

One late-stage lung cancer patient with simulated sphere target grid was included in this study. The sphere targets are 1.5cm in diameter and 4.3cm spacing. Four co-planar full arcs were used for optimization. The problem is formalized as finding optimal multi-leaf collimator (MLC) sequencing to cover N targets with K control points (CPs) for each arc. The state of each target's MLC opening at each CP is binary. In order to solve this NP-hard problem, the optimal solution was approximated by eliminating projection collision at each CP. MLC motion continuity and maximum speed were included in the cost function to ensure deliverability. The optimization started with randomized initial CP apertures, followed by solving state-transition equations for following CPs. Two grid arrays (9 and 10 targets respectively) were tested for plan quality. For each grid of target, the arc collimator angle was planned with 0 and 30 degrees for comparison. Prescription was 20 Gy per fraction. Monte Carlo simulation dose engine from matRad toolkit was used for dose calculation. Key dosimetric endpoints including target mean dose, D5%(Gy) and D95%(Gy), were reported.

RESULTS

Average calculation time on the AMD Ryzen 5 5600 × 6-Core 3.7GHz CPU and 32GB RAM platform varied from 31 to 44 minutes. One zero-degree collimator and one thirty-degree collimator were generated for each target array. For nine-target array, mean target dose from both plans ranged from 23.41 to 26.55 Gy, while D5%(Gy) and D95%(Gy) ranged from 25.45 to 30.16 Gy, and 20.00 to 22.21 Gy, respectively. For ten-target array, the range of target mean, D5%(Gy) and D95%(Gy) were 23.82 to 28.74 Gy, 26.50 to 33.11 Gy, and 20.00 to 22.49 Gy.

CONCLUSION

A fast, automatic planning solution for multi-focal DCA GRID therapy was developed. It provides clinically feasible plans with high efficiency for small target arrays for the late-stage cancer patient. The implementation provides excellent coverage for deep-seated tumors where alloy grid solution could fail to meet coverage objectives. Additional patients are needed in the future to further refine the technique.

Genome-wide identification and expression analysis of SlRR genes in response to abiotic stress in tomato

The cytokinin two-component signal transduction system (TCS) is involved in many biological processes, including hormone signal transduction and plant growth regulation. Although cytokinin TCS has been well characterized in Arabidopsis thaliana, its role in tomato remains elusive. In this study, we characterized the diversity and function of response regulator (RR) genes, a critical component of TCS, in tomato. In total, we identified 31 RR genes in the tomato genome. These SlRR genes were classified into three subgroups (type-A, type-B and type-C). Various stress-responsive cis-elements were present in the tomato RR gene promoters. Their expression responses under pesticide treatment were evaluated by transcriptome analysis. Their expression under heat, cold, ABA, salinity and NaHCO₃ treatments was further investigated by qRT-PCR and complemented with the available transcription data under these treatments. Specifically, SlRR13 expression was significantly upregulated under salinity, drought, cold and pesticide stress and was downregulated under ABA treatment. SlRR23 expression was induced under salt treatment, while the transcription level of SlRR1 was increased under cold and decreased under salt stress. We also found that GATA transcription factors played a significant role in the regulation of SlRR genes. Based on our results, tomato SlRR genes are involved in responses to abiotic stress in tomato and could be implemented in molecular breeding approaches to increase resistance of tomato to environmental stresses.

Seeking Repeating Anthropogenic Seismic Sources: Implications for Seismic Velocity Monitoring at Fault Zones

Seismic velocities in rocks are highly sensitive to changes in permanent deformation and fluid content. The temporal variation of seismic velocity during the preparation phase of earthquakes has been well documented in laboratories but rarely observed in nature. It has been recently found that some anthropogenic, high-frequency (>1 Hz) seismic sources are powerful enough to generate body waves that travel down to a few kilometers and can be used to monitor fault zones at seismogenic depth. Anthropogenic seismic sources typically have fixed spatial distribution and provide new perspectives for velocity monitoring. In this work, we propose a systematic workflow to seek such powerful seismic sources in a rapid and straightforward manner. We tackle the problem from a statistical point of view, considering that persistent, powerful seismic sources yield highly coherent correlation functions (CFs) between pairs of seismic sensors. The algorithm is tested in California and Japan. Multiple sites close to fault zones show high-frequency CFs stable for an extended period of time. These findings have great potential for monitoring fault zones, including the San Jacinto Fault and the Ridgecrest area in Southern California, Napa in Northern California, and faults in central Japan. However, extra steps, such as beamforming or polarization analysis, are required to determine the dominant seismic sources and study the source characteristics, which are crucial to interpreting the velocity monitoring results. Train tremors identified by the present approach have been successfully used for seismic velocity monitoring of the San Jacinto Fault in previous studies.

Tryptophan-96 in cytochrome P450 BM3 plays a key role in enzyme survival

Flavocytochrome P450 from Bacillus megaterium (P450BM3 ) is a natural fusion protein containing reductase and heme domains. In the presence of NADPH and dioxygen the enzyme catalyses the hydroxylation of long-chain fatty acids. Analysis of the P450BM3 structure reveals chains of closely spaced tryptophan and tyrosine residues that might serve as pathways for high-potential oxidizing equivalents to escape from the heme active site when substrate oxidation is not possible. Our investigations of the total number of enzyme turnovers before deactivation have revealed that replacement of selected tryptophan and tyrosine residues with redox inactive groups leads to a twofold reduction in enzyme survival time. Tryptophan-96 is critical for prolonging enzyme activity, suggesting a key protective role for this residue.

Monitoring Seismic Velocity Changes Across the San Jacinto Fault Using Train-Generated Seismic Tremors

Microseismic noise has been used for seismic velocity monitoring. However, such signals are dominated by low-frequency surface waves that are not ideal for detecting changes associated with small tectonic processes. Here we show that it is possible to extract stable, high-frequency body waves using seismic tremors generated by freight trains. Such body waves allow us to focus on small velocity perturbations in the crust with high spatial resolution. We report on 10 years of seismic velocity temporal changes at the San Jacinto Fault. We observe and map a two-month-long episode of velocity changes with complex spatial distribution and interpret the velocity perturbation as produced by a previously undocumented slow-slip event. We verify the hypothesis through numerical simulations and locate this event along a fault segment believed to be locked. Such a slow-slip event stresses its surroundings and may trigger a major earthquake on a fault section approaching failure.

Surface cysteines could protect the SARS-CoV-2 main protease from oxidative damage

The SARS-CoV-2 main protease (Mpro) is responsible for cleaving twelve nonstructural proteins from the viral polyprotein. Mpro, a cysteine protease, is characterized by a large number of noncatalytic cysteine (Cys) residues, none involved in disulfide bonds. In the absence of a tertiary-structure stabilizing role for these residues, a possible alternative is that they are involved in redox processes. We report experimental work in support of a proposal that surface cysteines on Mpro can protect the active-site Cys145 from oxidation by reactive oxygen species (ROS). In investigations of enzyme kinetics, we found that mutating three surface cysteines to serines did not greatly affect activity, which in turn indicates that these cysteines could protect Cys145 from oxidative damage.

Prevalence and spectrum of germline cancer susceptibility gene variants and somatic second hits in colorectal cancer

Colorectal cancer (CRC) is one of the most heritable cancers, and genetic factors play an important role in the increased CRC risk. However, the well-established CRC-risk genes were limited for explaining the increased risk of CRC individuals. Germline mutations in DNA damage repair (DDR) genes have also been reported to be implicated in CRC heritability. Here, we aimed to determine the prevalence and significance of germline DDR and well-established CRC-risk gene variants in CRCs with paired somatic analyses. Next-generation sequencing (NGS) was performed on tumor tissues and paired white blood cells collected from 2160 Chinese patients with CRC using well-designed 381- or 733-cancer gene panel. Germline/somatic variations were identified and assessed for pathogenicity and likely pathogenicity. Of 2160 CRCs, 136 pathogenic germline mutations in 133 patients (133/2160, 6.1%) were identified in 21 genes, including 19 out of 32 examined DDR genes. Compared with non-carriers, individuals with germline variants were prone to a higher level of microsatellite instability (MSI) and tumor mutational burden (TMB), and an earlier age of onset. Somatic sequencing identified second hits in 24/133 (18%) patients with germline variants. Among the mismatch repair (MMR) genes with germline mutations, the second hit significantly increased MSI and TMB, particularly apparent in MSH6. All MMR germline variation carriers further with a second hit were all MSI-H and had an extraordinarily high level of TMB. Collectively, approximately 6.1% of CRC patients carried pathogenic germline variants, and additional somatic second hit increases the genomic instability in CRC, whereas the more clinical significance warrants further study.

[Application of diffusion-weighted magnetic resonance imaging in evaluating the efficacy of radiotherapy and chemotherapy for esophageal cancer]

This study was a prospective single arm trial conducted in Zhejiang Jinhua Guangfu hospital from February 2018 to June 2020. A total of 39 patients (32 males and 7 females) with esophageal cancer, aged from 44 to 82 (69±9) years were enrolled. Diffusion weighted magnetic resonance imaging(MR-DWI) was implemented to evaluate the changes of apparent diffusion coefficient(ADC) value before and after chemoradiotherapy. The results showed that the ADC value after chemoradiotherapy was higher than that before treatment[(2.03±0.42)×10⁻³ mm ²/s vs (1.60±0.28)×10⁻³ mm²/s], and there was a positive correlation between the increase of ADC value and the prognosis of patients.

The Significance of MET Expression and Strategies of Targeting MET Treatment in Advanced Gastric Cancer

Background

Accurate assessment of predictive biomarker expression is critical in patient selection in clinical trials or clinical practice. However, changes in biomarker expression may occur after treatment. The aim of the present study was to evaluate the effects of chemotherapy on MET expression in gastric cancer (GC).

Methods

MET expression was examined immunohistochemically before and after treatment in 122 patients with unresectable or recurrent GC, and was evaluated according to H-score or the scoring criteria used in the MetMAb trial. MET gene amplification was assessed by chromogenic in situ hybridization (CISH). The antitumor effect of MET targeted therapy was investigated in human gastric cancer cells in vitro and in vivo, and the underlying molecular mechanisms were analyzed by western blot.

Results

MET expression was associated with Lauren classification as well as tumor differentiation by either scoring system. MET amplification was not associated with clinical characteristics. Of the 71 patients who had paired pre- and post-treatment tumor tissues, 28 patients (39%) were initially positive for MET expression, and 43 (61%) were negative. Twenty-five patients (35%) showed significant changes in MET expression after treatment (P=0.007). Additionally, there was a concomitant overexpression of MET and HER2 in a subset of GC patients. MET inhibitor volitinib could significantly inhibit cell proliferation and xenograft growth in vitro and in vivo in MKN45 cells with MET and phosphorylated MET (pMET) high expressions via suppressing downstream PI3K/Akt and MAPK signaling pathways. Furthermore, combination therapy targeting both MET and HER2 demonstrated a synergistic antitumor activity.

Conclusions

MET expression is altered post chemotherapy and MET status should be evaluated in real-time. Both MET and pMET expressions might need to be considered for patients suitable for volitinib treatment.

Folate hydrolase-1 (FOLH1) is a novel target for antibody-based brachytherapy in Merkel cell carcinoma

Backgrounds

Folate Hydrolase‐1 (FOLH1; PSMA) is a type II transmembrane protein, luminally expressed by solid tumour neo‐vasculature. Monoclonal antibody (mAb), J591, is a vehicle for mAb‐based brachytherapy in FOLH1+ cancers. Brachytherapy is a form of radiotherapy that involves placing a radioactive material a short distance from the target tissue (e.g., on the skin or internally); brachytherapy is commonly accomplished with the use of catheters, needles, metal seeds and antibody or small peptide conjugates. Herein, FOLH1 expression in primary (p) and metastatic (m) Merkel cell carcinoma (MCC) is characterized to determine its targeting potential for J591‐brachytherapy.

Materials & Methods

Paraffin sections from pMCC and mMCC were evaluated by immunohistochemistry for FOLH1. Monte Carlo simulation was performed using the physical properties of conjugated radioisotope lutetium‐177. Kaplan–Meier survival curves were calculated based on patient outcome data and FOLH1 expression.

Results

Eighty‐one MCC tumours were evaluated. 67% (54/81) of all cases, 77% (24/31) pMCC and 60% (30/50) mMCC tumours were FOLH1+. Monte Carlo simulation showed highly localized ionizing tracks of electrons emitted from the targeted neo‐vessel. 42% (34/81) of patients with FOLH1+/− MCC had available survival data for analysis. No significant differences in our limited data set were detected based on FOLH1 status (p = 0.4718; p = 0.6470), staining intensity score (p = 0.6966; p = 0.9841) or by grouping staining intensity scores (− and + vs. ++, +++, +++) (p = 0.8022; p = 0.8496) for MCC‐specific survival or recurrence free survival, respectively.

Conclusions

We report the first evidence of prevalent FOLH1 expression within MCC‐associated neo‐vessels, in 60‐77% of patients in a large MCC cohort. Given this data, and the need for alternatives to immune therapies it is appropriate to explore the safety and efficacy of FOLH1‐targeted brachytherapy for MCC.

What's already known about this topic?

We report the first evidence of prevalent folate hydrolase‐1 (FOLH1; also known as prostate‐specific membrane antigen) expression within MCC‐associated neovessels.

What does this study add?

Herein, FOLH1 expression in Merkel cell carcinoma neovasculature is validated, and the therapeutic mechanism of specific, systemic targeting of disseminated disease with antibody‐based brachytherapy, is defined.

Effect of menopausal symptom treatment options on palpitations: a systematic review

This systematic review provides an overview of the effects of menopausal symptom treatment options on palpitations, defined as feelings of missed or exaggerated heart beats, reported by perimenopausal and postmenopausal women. Guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, searches were conducted in PubMed, CINAHL and PsycINFO to identify articles meeting pre-specified inclusion criteria. Of 670 unique articles identified, 37 were included in the review. Treatments included drug therapies and non-drug therapies. Palpitations were studied as an outcome in 89% of articles and as an adverse effect in 11%. Articles provided mostly level II/III evidence due to their design and/or small sample sizes. Based on available evidence, no therapies can be fully recommended for clinical practice. Only some hormonal agents (e.g. estradiol) can be recommended with caution based on some positive evidence for reducing palpitation prevalence or severity. However, other drug therapies (e.g. moxonidine, atenolol), dietary supplementary treatments (e.g. isoflavones, Rheum rhaponticum, sage), cognitive-behavioral intervention and auricular acupressure cannot be recommended given the existing evidence. Additional well-designed randomized controlled treatment trials focusing on palpitations during the menopause transition as an inclusion criteria and outcome are needed to advance the field.

PD-1 restrains IL-17A production from γδ T cells to modulate acute radiation-induced lung injury

Background

Combining radiotherapy (RT) with programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) inhibitors has been shown to enhance anti-tumor effects in the treatment of non-small cell lung carcinoma (NSCLC). Pulmonary toxicity is a major adverse effect of thoracic RT in NSCLC patients, whether it is administered alone or in combination with PD-1/PD-L1 inhibitors. This study aimed to evaluate the potential pulmonary toxicity of RT combined with concurrent PD-1 inhibitor and to clarify the underlying mechanisms.

Methods

Radiation-induced lung injury (RILI) was induced in C57BL/6 mice by given 24 Gy in three fractions on consecutive days, with or without concurrent injection of anti-PD-1 antibody. On days 3, 7, 14, and 28 after the first exposure to irradiation, lung tissue and peripheral blood samples were collected from the mice. Histological injury was analyzed, and inflammatory cell infiltration and interleukin (IL)-17A production in the lung tissues were quantified.

Results

Mice that received irradiation with concurrent administration of anti-PD-1 antibody had the highest histological score for RILI. In the murine lung tissues, the levels of PD-1 and IL-17A expression were increased in γδ T cells but not in the other CD3⁺ T cells after irradiation. Concurrent blockade of PD-1 enhanced IL-17A production from γδ T cells in the lung tissues after irradiation. In the mice with acute RILI, concurrent administration of anti-PD-1 antibody exaggerated pulmonary inflammation, with significantly increased levels of neutrophilic infiltration and IL-17A detected in both the lung and blood.

Conclusions

PD-1 could restrain IL-17A production from γδ T cells to modulate acute RILI. The concurrent administration of anti-PD-1 antibody aggravates the severity of acute RILI. More attention should be paid to pulmonary toxicity in patients undergoing thoracic RT with concurrent anti-PD-1 immunotherapy.

Superior rectal artery embolization for bleeding internal hemorrhoids

BACKGROUND

The aim of the present study was to evaluate clinical efficacy and safety of superselective embolization of the superior rectal artery (SRA) for the treatment of internal hemorrhoidal bleeding.

METHODS

Patients with stage II and stage III internal hemorrhoids, treated by interventional embolization of the SRA in our department between January 2017 and June 2019 were retrospectively evaluated. All patients suffering from disabling chronic hematochezia and some with relative contraindications for operation (n = 17) or rejection of conventional hemorrhoidectomy (n = 15). Superselective SRA branch embolization was performed using gelatin sponge particles (350-560 μm) and metallic coils (2-3 mm). This treatment process was planned by a multidisciplinary team consisting of proctologist, gastroenterologist and radiologist. The surgical efficacy, postoperative complications and follow-up outcomes were observed.

RESULTS

There were 32 patients (18 males, mean age 52 ± 12 years, range: 22-78 years), 12 (37%) with stage II hemorrhoids and 20 (63%) with stage III hemorrhoids. Embolization was successful in all patients, and bleeding symptoms resolved in 27 (84.4%) patients. The remaining 5 (15.6%) patients underwent either stapled hemorrhoidopexy (n = 4) or sclerotherapy (n = 1). Some patients experienced different degrees of pain (n = 4;12.5%), low fever (n = 11;34.4%), and tenesmus (n = 17;53.1%), which all spontaneously regressed without further treatment. All patients were followed up for at least 1 year. There were no serious complications, such as infection, intestinal ischemia or massive hemorrhage. Four patients (14.8%) had rebleeding during the first months of follow-up. All patients with re-bleeding were successfully treated with internal iliac arteriography and branch embolization and did not experience further bleeds after a minimum follow up 3 months follow-up.

CONCLUSIONS

The short-term efficacy of superselective SRA embolization for grade II-III internal hemorrhoids is good, and this method is safe and feasible.

Cyclophosphamide induces a significant increase in iron content in the liver and spleen of mice

Objective:

Oxidative stress is one of the major mechanisms of cyclophosphamide (CPX)-induced toxicities. However, it is unknown how CPX induces oxidative stress. Based on the available information, we speculated that CPX could increase iron content in the tissues and then induce oxidative stress.

Method:

We tested this hypothesis by investigating the effects of CPX on iron and ferritin contents, expression of transferrin receptor 1 (TfR1), ferroportin 1 (Fpn1), iron regulatory proteins (IRPs), hepcidin, and nuclear factor erythroid 2-related factor-2 (Nrf2) in the liver and spleen, and also on reticulocyte count, immature reticulocyte fraction, and hemoglobin (Hb) in the blood in c57/B6 mouse.

Results:

We demonstrated that CPX could induce a significant increase in iron contents and ferritin expression in the liver and spleen, notably inhibit erythropoiesis and Hb synthesis and lead to a reduction in iron usage. The reduced expression in TfR1 and Fpn1 is a secondary effect of CPX-induced iron accumulation in the liver and spleen and also partly associated with the suppressed IRP/iron-responsive element system, upregulation of hepcidin, and downregulation of Nrf2.

Conclusions:

The reduced iron usage is one of the causes for iron overload in the liver and spleen and the increased tissue iron might be one of the mechanisms for CPX to induce oxidative stress and toxicities.

Abstract P1-02-10: Early stage breast cancer screening using an emerging novel liquid biopsy screening technology

Background: An emerging novel liquid biopsy technology called Cancer Differentiation Analysis (CDA) has been evaluated as a viable early stage breast cancer screening tool. CDA technology is a blood-sample based, multi-level, multi-parameter diagnostic method which detects signals from both protein, cellular, and to some extent, molecular levels, in which multiple aspects of information can be collected to improve diagnostic accuracy, even for early stage of cancer. Improving capability to screen breast cancer is an important on-going research effort, as breast cancer represents a leading cancer with high incidence rate.

Methods: In this single-blind study, 22 breast cancer patients and 25 healthy individuals were recruited at Changhai Hospital of Shanghai. Histopathological examination results of breast cancer patients were collected, 22 cases were diagnosed as infiltrating ductal carcinoma of breast, of which 10 patients were stage I breast cancer. 25 individuals were confirmed healthy after physical examinations. Peripheral blood was drawn in EDTA tubes For CDA tests. CDA data of 22 breast cancer patients and 25 healthy individuals were conducted using SPSS, and the results were shown in the table below.

Results: The average CDA of breast cancer, stageIbreast cancer, and controls were 43.20, 44.17 and 36.17 (rel. units) respectively as shown in Table 1. Both breast cancer and stage I breast cancer could be significantly distinguished from the control (p = 0.000, p = 0.001, respectively). For stage I breast cancer vs. control group, Area under ROC curve was 0.876, sensitivity and specificity were both 80.0% (Table 2). In contrast to traditional breast cancer screening methodologies which have relatively low sensitivity and high false positives for stage I detection, often with radiation side effects and high costs, advantages of CDA technology include ability to detect early stage cancer with relatively high sensitivity and specificity, and it is also highly cost effective without side effects.

Conclusions: Initial results showed that CDA technology could effectively distinguish stageIbreast cancer from healthy individuals, CDA could be a potential candidate for breast cancer screening.

Table 1Summary of CDA test resultsGroupSample SizeAge RangeAge MeanAge MedianCDA Mean (rel. units)CDA Median (rel. units)CDA STDEVControl2523 - 67413735.6336.176.98Breast Cancer2239 - 78545343.2042.304.18Stage I Breast Cancer1043 - 78595944.1743.254.29Stage II Breast Cancer839 - 55474941.2840.303.06Stage III Breast Cancer255555542.2042.202.12Stage IV Breast Cancer251 - 64585847.0047.007.78

Table 2AUC, Sensitivity and Specificity of Control vs. Stage I breast cancerStage I Breast Cancer vs. ControlArea Under the CurveSensitivitySpecificity 0.87680.0%80.0%

Citation Format: Liu C, Dou J, Sheng Y, Wu J, Hu W, Li Y, Lin Y, Tao H, Tang X, Du X, Yu C. Early stage breast cancer screening using an emerging novel liquid biopsy screening technology [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 P1-02-10.

Abstract P1-02-09: CDA screening technology for multi-ethnic group, early stage breast cancer screening

Background: Breast cancer is the second leading cause of death from cancer in American women. Current breast cancer screening technologies have issues with poor sensitivity for early stage breast cancer, high false positives, radiation side effects, etc. Cancer Differentiation Analysis (CDA) technology is a blood-sample based, multi-level, multi-parameter diagnostic method which detects signals from both proteins, cells, and to some extent, molecular level, in which multiple aspects of information are collected to improve diagnostic accuracy. CDA technology has been investigated as a viable clinical utility in breast cancer screening, particularly for early stage breast screening with clear advantages (both whole blood and serum can be used, ability to detect early, easy, simple, no side effects, and high degree of sensitivity and specificity).

Methods: In this study, the human subjects involved are Caucasians, with serum samples of 44 pathologically confirmed breast cancer patients and 34 healthy individuals from 3 blood bank centers in the USA, of which 40 cases were stageIbreast cancer, 2 cases were stageII, and the other 2 cases were stage III breast cancer. CDA data of 44 breast cancer patients and 34 healthy individuals were collected in US lab and analyzed using SPSS, and the results were shown in the table below. Results from the above study was compared with a clinical study on Asian group with data collected in lab in China using CDA technology.

Results: The average CDA value of all breast cancer and stageIbreast cancer samples, and controls were 45.99, 45.76 and 42.36 (rel. units) respectively (see Table 1). Both breast cancer and stageIbreast cancer could be significantly distinguished from the control group (p < 0.001) (Table 2). For stageIbreast cancer vs. control group, Area under ROC curve was 0.727, sensitivity and specificity were 62.5% and 82.4% respectively, which is higher than a typical mammogram. To compare with different ethnic groups, data collected on an Asian group is also shown in Table 2, which showed that overall, AUC, sensitivity and specificity are comparable (some difference may be attributed to sample type difference (whole blood vs. serum)) for early stage breast cancer patients for those two ethnic groups, demonstrating that CDA technology can be extended to multiple ethnic groups.

Conclusions: CDA screening can be extended to different ethnic group including Caucasian and Asian with good sensitivity and specificity for stageIbreast cancer.

We thank Ugur Basmaci, Sunsil Pandit and Sharon Vorse-Yu for their support.

Table 1Summary of CDA Test ResultsGroupSample SizeAge RangeAge MeanAge MedianCDA Mean (rel. units)CDA Median (rel. units)CDA STDEVControl3436 -79575742.3642.652.75Breast Cancer4436 – 77606145.9946.504.22Stage I Breast Cancer4036 – 77606145.7645.554.26Stage II Breast Cancer251 – 64585847.0547.054.88Stage III Breast Cancer262 – 75696949.5049.502.55

Table 2AUC, Sensitivity and Specificity of Control vs. Stage I Breast CancerStage I Breast Cancer vs. ControlArea Under the CurveSensitivitySpecificityCaucasian (Stage I)0.72762.5%82.4%Asian# (Stage I)0.87680.0%80.0%# Whole blood samples. 10 stage I breast cancer samples and 25 control samples

Citation Format: Tao H, Lin Y, Liu C, Dou J, Sheng Y, Wu J, Hu W, Li Y, Tang X, Yu C, Du X. CDA screening technology for multi-ethnic group, early stage breast cancer screening [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 P1-02-09.

Two Tryptophans Are Better Than One in Accelerating Electron Flow through a Protein

We have constructed and structurally characterized a Pseudomonas aeruginosa azurin mutant Re126WWCuI , where two adjacent tryptophan residues (W124 and W122, indole separation 3.6-4.1 Å) are inserted between the CuI center and a Re photosensitizer coordinated to the imidazole of H126 (ReI(H126)(CO)3(4,7-dimethyl-1,10-phenanthroline)+). CuI oxidation by the photoexcited Re label (*Re) 22.9 Å away proceeds with a ∼70 ns time constant, similar to that of a single-tryptophan mutant (∼40 ns) with a 19.4 Å Re-Cu distance. Time-resolved spectroscopy (luminescence, visible and IR absorption) revealed two rapid reversible electron transfer steps, W124 → *Re (400-475 ps, K 1 ≅ 3.5-4) and W122 → W124•+ (7-9 ns, K 2 ≅ 0.55-0.75), followed by a rate-determining (70-90 ns) CuI oxidation by W122•+ ca. 11 Å away. The photocycle is completed by 120 μs recombination. No photochemical CuI oxidation was observed in Re126FWCuI , whereas in Re126WFCuI , the photocycle is restricted to the ReH126W124 unit and CuI remains isolated. QM/MM/MD simulations of Re126WWCuI indicate that indole solvation changes through the hopping process and W124 → *Re electron transfer is accompanied by water fluctuations that tighten W124 solvation. Our finding that multistep tunneling (hopping) confers a ∼9000-fold advantage over single-step tunneling in the double-tryptophan protein supports the proposal that hole-hopping through tryptophan/tyrosine chains protects enzymes from oxidative damage.

[Rosai-Dorfman disease with nasal septum involvement:two cases report]

Clinical data of 2 cases with Rosai-Dorfman disease(RDD) originating from nasal septal mucosa were reported retrospectively,and the pertinent literature was reviewed. Without specific clinical features,RDD in nasal cavity could be misdiagnosed easily. Pathology revealed different morphologies of cell proliferation with engulfed lymphocytes,plasma cells and neutrophils. Immunohistochemical staining showed S-100(+),CD68(+)，CD1(-).RDD disease generally has a benign course and is self-limited. Its diagnosis depends mainly on biopsy．As for the treatment of this disease,the strategies are not systemic and standard. Surgical treatment is used to excise the mass in nasal cavity,glucocorticoids treatment after surgery is inconclusive. The long-term effect need to be further observed．.

[Clinical application of a self-developed bone dust collector in mastoid cavity obliteration following mastoidectomy]

Objective: To introduce a self-developed bone dust collector designed by the authors and evaluate its efficiency in mastoid obliteration following mastoidectomy. Methods: Consecutive patients, from April 2017 to March 2018, who prepared to receive mastoidectomy were randomly divided into two groups, and in each group the bone dust was harvested by self-developed bone dust collector or by conventional used method respectively in mastoidectomy. The amount of the harvested bone dust and the time consumed in the collecting procedure were compared between two groups. The infection of the bone dust after mastoid obliteration was also evaluated during follow up. Results: 33 patients were recruited in bone dust collector group, and 31 patients in conventional method group.There is no significance of difference between two groups in sex ratio, age and pneumatization of mastoid cells (P>0.05 for all). The median amount of bone dust harvested by bone dust collector was significantly larger than that collected by conventional method (1.8 g vs 1.1 g, P<0.05). The median time spent in bone dust collector group was significantly shorter than that spent in conventional method group (4 minutes vs 6 minutes, P<0.05). No bone dust infection was found in the follow-up in all patients. Conclusion: The present self-developed bone dust collector is a easy and useful apparatus which can significantly improve the efficiency of collecting bone dust in mastoidectomy.

[Application of anoptomagnetic probe Gd-DO3A-EA-FITC in imaging and analyzing the brain interstitial space]

OBJECTIVE

To investigate the application of the optical magnetic bimodal molecular probe Gd-DO3A-ethylthiouret-fluorescein isothiocyanate (Gd -DO3A-EA-FITC) in brain tissue imaging and brain interstitial space (ISS).

METHODS

In the study, 24 male SD rats were randomly divided into 3 groups, including magnetic probe group (n=6), optical probe group (n=6) and optical magnetic bimodal probe group (n=12), then the optical magnetic bimodal probe group was divided equally into magnetic probe subgroup (n=6) and optical probe subgroup (n=6). Referencing the brain stereotaxic atlas, the coronal globus pallidus as center level, the probes including gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA), fluorescein isothiocyanate (FITC) and Gd-DO3A-EA-FITC of 2 μL (10 mmol/L) were injected into the caudate nucleus respectively, magnetic resonance imaging (MRI) was performed in the magnetic probe group and magnetic probe subgroup to image the dynamic diffusion and distribution of the probes in the brain ISS, a self-developed brain ISS image processing system was used to measure the diffusion coefficient, clearance, volume fraction and half-time in these two groups. Laser scanning confocal microscope (LSCM) was performed in vitro in the optical probe group and optical probe subgroup for fluorescence imaging at the time points 2 hours after the injection of the probe, and the distribution in the oblique sagittal slice was compared with the result of the first two groups.

RESULTS

For the magnetic probe group and magnetic probe subgroup, there were the same imaging results between the probes of Gd-DTPA and Gd-DO3A-EA-FITC. The diffusion parameters of Gd-DTPA and Gd-DO3A-EA-FITC were as follows: the average diffusion coefficients [(3.31±0.11)×10^-4 mm²/s vs. (3.37±0.15)×10^-4 mm²/s, t=0.942, P=0.360], the clearance [(3.04±0.37) mmol/L vs. (2.90±0.51) mmol/L, t=0.640, P=0.531], the volume fractions (17.18%±0.14% vs. 17.31%±0.15%, t=1.961, P=0.068), the half-time [(86.58±3.31) min vs. (84.61±2.38) min, t=1.412, P=0.177], the diffusion areas [(23.25±0.68) mm² vs. (22.71±1.00) mm², t=1.100, P=0.297]. The statistical analysis of each brain was made by t test, and the diffusion parameters were not statistically significant. Moreover, for the optical probe group and optical probe subgroup, the diffusion area of Gd-DO3A-EA-FITC [(22.61±1.16) mm²] was slightly larger than that of FITC [(22.10±1.29) mm²], the statistical analysis of each brain was made by t test, and the diffusion parameters were not statistically significant (t=0.713, P=0.492).

CONCLUSION

Gd-DO3A-EA-FITC shows the same imaging results as the traditional GD-DTPA, and it can be used in measuring brain ISS.

[Dynamic visual analysis of neutrophils chemotaxis in peritoneal cavity of schizophrenic model in mice]

OBJECTIVE

To compare the differences of neutrophils chemotaxis ability in peritoneal cavity between normal rats and schizopherenic rats with cell dynamic visualization system.

METHODS

In the study,18 healthy Kunming rats were randomly divided into 3 groups which were control group (n=6), 0.3 mg/kg MK-801 treatment group (n=6), 0.6 mg/kg dizocilpine maleate (MK-801) treatment group(n=6), extracted neutrophils separately, and observed the morphology and counted under a microscope. Each group of cells was divided into two parts for chemotactic experiment, called chemokine agent treatment group and no chemokine agent treatment group respectively, indicating control 1, 0.3 mg/kg MK-801 treatment 1,0.6 mg/kg MK-801 treatment 1 and control 2, 0.3 mg/kg MK-801 treatment 2,0.6 mg/kg MK-801 treatment 2. The dynamic migration of cells was recorded using the NIS-Elements software, and TAXIScan Analyzer 2 software was used to select 30 cells (n=30) in each group of cells and analyze cells migration trajectory, speed and distance, and use pair test and One-Way analysis of variance for statistical analysis.

RESULTS

The number of neutrophils in control group, 0.3 mg/kg MK-801 treatment group and 0.6 mg/kg MK-801 treatment group were(1.00±0.03)×10⁴/mL,(0.05±0.02)×10⁴/mL,(0.32±0.01)×10⁴/mL respectively, the differences of results were statistically significant(P<0.05).Under the effect of chemotactic agent,the directional migration capability of neutrophils in control group 1, 0.3 mg/kg MK-801 treatment group 1 and 0.6 mg/kg MK-801 treatment group 1 were(0.85±0.11) radian,(1.00±0.11) radian,(0.96±0.10) radian respectively (P<0.05); the migration velocities of neutrophils were (0.09±0.02) μm/s,(0.12±0.01) μm/s,(0.14±0.01) μm/s respectively (P<0.05);the migration distances of neutrophils were (94.26±0.02) μm,(134.61±0.01) μm,(156.19±0.01) μm respectively(P<0.05).

CONCLUSION

Compared with neutrophils in peritoneal cavity of control group, the neutrophils in peritoneal cavity of schizophrenic rats have stronger chemotactic movement ability.

Whole-exome sequencing for diagnosis of hereditary ichthyosis

BACKGROUND

Hereditary ichthyosis constitutes a diverse group of cornification disorders. Identification of the molecular cause facilitates optimal patient care.

OBJECTIVE

We wanted to estimate the diagnostic yield of applying whole-exome sequencing (WES) in the routine genetic workup of inherited ichthyosis.

METHODS

During a 3-year-period, all ichthyosis patients, except X-linked and mild vulgar ichthyosis, consecutively admitted to a university hospital clinic were offered WES with subsequent analysis of ichthyosis-related genes as a first-line genetic investigation. Clinical and molecular data have been collected retrospectively.

RESULTS

Genetic variants causative for the ichthyosis were identified in 27 of 34 investigated patients (79.4%). In all, 31 causative mutations across 13 genes were disclosed, including 12 novel variants. TGM1 was the most frequently mutated gene, accounting for 43.7% of patients suffering from autosomal recessive congenital ichthyosis (ARCI).

CONCLUSION

Whole-exome sequencing appears an effective tool in disclosing the molecular cause of patients with hereditary ichthyosis seen in clinical practice and should be considered a first-tier genetic test in these patients.

Homozygous KIDINS220 loss-of-function variants in fetuses with cerebral ventriculomegaly and limb contractures

Heterozygous mutations in KIDINS220 were recently suggested a cause of spastic paraplegia, intellectual disability, nystagmus and obesity. All patients carried terminal nonsense de novo mutations that seemed to escape nonsense-mediated mRNA decay. The mechanism for pathogenicity is yet unexplained, as it seems that heterozygous loss-of-function variants of KIDINS220 are generally well tolerated. We present a consanguineous couple who experienced four pregnancy terminations due to repeated findings in the fetuses comprising enlarged cerebral ventricles and limb contractures. Exome sequencing in two of the aborted fetuses revealed a shared homozygous frameshift variant in exon 24 in KIDINS220. Sanger sequencing of the variant in available family members showed complete segregation with the affection status, resulting in a LOD score of 2.5 under an autozygous inheritance model. mRNA studies revealed destruction of the original splice site, resulting in an out-of-frame transcript and introduction of a premature termination codon in exon 25. Premature termination codons in this position are likely to cause activation of nonsense-mediated mRNA decay and result in complete absence of KIDINS220 protein in individuals homozygous for the variant. The phenotype of the presented fetuses overlaps with findings in functional studies of knockout Kidins220 mice embryos that are non-viable with enlarged cerebral ventricles. The human fetuses also exhibit several similarities to the milder phenotype described in patients with heterozygous KIDINS220 mutations. We hence propose that the identified homozygous loss-of-function variant in KIDINS220 causes the phenotype in the presented fetuses, and that this represents a hitherto undescribed severe autosomal recessive neurodevelopmental disorder.

Comparative analysis of ferroelectric domain statistics via nonlinear diffraction in random nonlinear materials

We present an indirect, non-destructive optical method for domain statistic characterization in disordered nonlinear crystals having homogeneous refractive index and spatially random distribution of ferroelectric domains. This method relies on the analysis of the wave-dependent spatial distribution of the second harmonic, in the plane perpendicular to the optical axis in combination with numerical simulations. We apply this technique to the characterization of two different media, Calcium Barium Niobate and Strontium Barium Niobate, with drastically different statistical distributions of ferroelectric domains.

Topiramate modulates post-infarction inflammation primarily by targeting monocytes or macrophages

Aims

Monocytes/macrophages response plays a key role in post-infarction inflammation that contributes greatly to post-infarction ventricular remodelling and cardiac rupture. Therapeutic targeting of the GABAA receptor, which is enriched in monocytes/macrophages but not expressed in the myocardium, may be possible after myocardial infarction (MI).

Methods and results

After MI was induced by ligation of the coronary artery, C57BL/6 mice were intraperitoneally administered with one specific agonist or antagonist of the GABAA receptor (topiramate or bicuculline), in the setting of presence or depletion of monocytes/macrophages. Our data showed that within the first 2 weeks after MI, when monocytes/macrophages dominated, in contrast with bicuculline, topiramate treatment significantly reduced Ly-6Chigh monocyte numbers by regulating splenic monocytopoiesis and promoted foetal derived macrophages preservation and conversion of M1 to M2 or Ly-6Chigh to Ly-6Clow macrophage phenotype in the infarcted heart, though GABAAergic drugs failed to affect M1/M2 or Ly-6Chigh/Ly-6Clow macrophage polarization directly. Accordingly, pro-inflammatory activities mediated by M1 or Ly-6Chigh macrophages were decreased and reparative processes mediated by M2 or Ly-6Clow macrophages were augmented. As a result, post-infarction ventricular remodelling was attenuated, as reflected by reduced infarct size and increased collagen density within infarcts. Echocardiographic indices, mortality and rupture rates were reduced. After depletion of monocytes/macrophages by clodronate liposomes, GABAAergic drugs exhibited no effect on cardiac dysfunction and surrogate clinical outcomes.

Conclusion

Control of the GABAA receptor activity in monocytes/macrophages can potently modulate post-infarction inflammation. Topiramate emerges as a promising drug, which may be feasible to translate for MI therapy in the future.

Colonic microbiota can promote rapid local improvement of murine colitis by thioguanine independently of T lymphocytes and host metabolism

OBJECTIVE

Mercaptopurine (MP) and pro-drug azathioprine are 'first-line' oral therapies for maintaining remission in IBD. It is believed that their pharmacodynamic action is due to a slow cumulative decrease in activated lymphocytes homing to inflamed gut. We examined the role of host metabolism, lymphocytes and microbiome for the amelioration of colitis by the related thioguanine (TG).

DESIGN

C57Bl/6 mice with or without specific genes altered to elucidate mechanisms responsible for TG's actions were treated daily with oral or intrarectal TG, MP or water. Disease activity was scored daily. At sacrifice, colonic histology, cytokine message, caecal luminal and mucosal microbiomes were analysed.

RESULTS

Oral and intrarectal TG but not MP rapidly ameliorated spontaneous chronic colitis in Winnie mice (point mutation in Muc2 secretory mucin). TG ameliorated dextran sodium sulfate-induced chronic colitis in wild-type (WT) mice and in mice lacking T and B lymphocytes. Remarkably, colitis improved without immunosuppressive effects in the absence of host hypoxanthine (guanine) phosphoribosyltransferase (Hprt)-mediated conversion of TG to active drug, the thioguanine nucleotides (TGN). Colonic bacteria converted TG and less so MP to TGN, consistent with intestinal bacterial conversion of TG to so reduce inflammation in the mice lacking host Hprt. TG rapidly induced autophagic flux in epithelial, macrophage and WT but not Hprt^-/- fibroblast cell lines and augmented epithelial intracellular bacterial killing.

CONCLUSIONS

Treatment by TG is not necessarily dependent on the adaptive immune system. TG is a more efficacious treatment than MP in Winnie spontaneous colitis. Rapid local bacterial conversion of TG correlated with decreased intestinal inflammation and immune activation.