Expression and antimicrobial activity of the recombinant bovine lactoferricin in Pichia pastoris

Lactoferricin, a multifunctional peptide located in the N-terminal region of lactoferrin, has a broad-spectrum bacteriostatic activity. It is a promising candidate as a food additive and immune fortification agent and does not have the risks associated with drug residues and drug resistance. First, we performed promoter and host cell screening to achieve the recombinant expression of lactoferricin in Pichia pastoris, showing an initial titer of 19.5 mg/L in P. pastoris X-33 using PAOX1 promoter. Second, we constructed a 0030-α hybrid signal peptide by fusing the 0030 signal peptide with the pro-sequence of α-factor secretory signal peptide. This further increased the production of lactoferricin, with a titer of 28.8 mg/L in the fermentation supernatant in the shaking flask. Next, we increased the expression of lactoferricin by fusing it with anionic antioxidant peptides. The neutralization of positive charges yielded a titer of 55.3 mg/L in the shaking flask, and a highest titer of 193.9 mg/L in a 3-L bioreactor. The antimicrobial activity analysis showed that recombinant-expressed lactoferricin exhibited potent antibacterial activity against Escherichia coli, Bacillus subtilis, and Staphylococcus aureus. This study provides a reference for the construction of microbial cell factories capable of efficiently synthesizing antimicrobial peptides.

Prenatal exome sequencing analysis in fetuses with central nervous system anomalies

OBJECTIVE

To evaluate the utility of prenatal exome sequencing (pES) in fetuses with central nervous system (CNS) abnormalities.

METHODS

This was a retrospective cohort study of fetuses identified to have CNS abnormality on prenatal ultrasound and/or magnetic resonance imaging. All fetuses were first analyzed by chromosomal microarray analysis (CMA). Fetuses with a confirmed aneuploidy or causal pathogenic copy-number variant (CNV) on CMA did not undergo pES analysis and were excluded, while those with a negative CMA result were offered pES testing.

RESULTS

Of the 167 pregnancies included in the study, 42 (25.1%) were identified to have a pathogenic or likely pathogenic (P/LP) variant. The diagnostic rate was significantly higher in fetuses with a non-isolated CNS abnormality than in those with a single CNS abnormality (35.7% (20/56) vs 14.5% (8/55); P = 0.010). Moreover, when a fetus had three or more CNS abnormalities, the positive diagnostic rate increased to 42.9%. A total of 25/42 (59.5%) cases had de-novo mutations, while, in the remaining cases, mutations were inherited and carried a significant risk of recurrence. Families whose fetus carried a P/LP mutation were more likely to choose advanced pregnancy termination than those with a variant of uncertain significance, secondary/incidental finding or negative pES result (83.3% (25/30) vs 41.3% (38/92); P < 0.001).

CONCLUSION

pES improved the identification of genetic disorders in fetuses with CNS anomalies without a chromosomal abnormality or CNV identified on CMA, regardless of the number of CNS anomalies and presence of extracranial abnormality. We also demonstrated that pES findings can significantly impact parental decision-making. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Predicting Local Control with Dosimetric Parameters in Patients Receiving Individualized Stereotactic Ablative Radiotherapy for Lung Tumors

PURPOSE/OBJECTIVE(S)

Stereotactic ablative radiotherapy (SABR) is an effective treatment option for lung tumors. The individualized lung tumor SABR (iSABR) trial was a phase II single-arm study that personalized lung tumor SABR dose and fractionation based on tumor size, location, and histology with very low rates of local recurrence (LR). A secondary analysis of this trial was conducted to assess for potential dosimetric predictors of LR, in order to help guide future clinical treatment planning.

MATERIALS/METHODS

From 2011 to 2018, local, regional and distant recurrence data were prospectively collected from 204 patients (261 lung SABR treatments) enrolled in a prospective trial. Baseline characteristics and treatment details were evaluated. Dosimetric and treatment plan parameters were evaluated for their potential to predict LR, using logistic regression and chi-squared analyses.

RESULTS

The majority of treated tumors were peripheral (71%, vs 29% central), primary lesions (76%, versus 24% metastatic), and of adenocarcinoma histology (67%, versus 13% squamous cell carcinoma and 19% other). The median follow-up was 24 months (range 2-95). Twenty-seven (10.3%) LRs occurred, with a median time to LR of 15 months (range 6-81 months). There were no significant associations between the overall cohort and the dosimetric parameters. However, for the multi-fraction cohort, an increased proportion of the PTV receiving 110% and 115% of the prescription dose were associated with lower LR (p = 0.01 and p = 0.01 respectively). Specifically for the 50 Gy in 4 fraction cohort, an increased D1cc, D0.03cc, as well as the proportion of the PTV receiving 110%, 115%, and 120% of the prescription dose were associated with lower LR (p < 0.001, p = 0.001, p = 0.003, p < 0.001, p = 0.004, respectively). There was no association of LR with prescription dose expressed as biologically effective dose using an alpha/beta of 10 Gy (BED10), D99%, or single- versus multi-fraction regimens.

CONCLUSION

SABR for lung tumors using the individualized protocol on this trial showed excellent LR rates. We identified dosimetric parameters that were associated with LR, including V110% and V115% within the multi-fraction cohort, as well as the 50 Gy in 4 fraction cohort the D1cc, D0.03cc, and proportions of the PTV receiving 110%, 115%, and 120% of the prescription dose in the 50 Gy in 4 fraction cohort. Optimal thresholds for these parameters will be identified in further analyses. There did not appear to be an association with LR and BED10, D99%, or comparing single- vs multi-fraction regimens.

[Functional analysis of functional membrane microdomains in the biosynthesis of menaquinone-7]

Functional membrane microdomains (FMMs) that are mainly composed of scaffold proteins and polyisoprenoids play important roles in diverse cellular physiological processes in bacteria. The aim of this study was to identify the correlation between MK-7 and FMMs and then regulate the MK-7 biosynthesis through FMMs. Firstly, the relationship between FMMs and MK-7 on the cell membrane was determined by fluorescent labeling. Secondly, we demonstrated that MK-7 is a key polyisoprenoid component of FMMs by analyzing the changes in the content of MK-7 on cell membrane and the changes in the membrane order before and after destroying the integrity of FMMs. Subsequently, the subcellular localization of some key enzymes in MK-7 synthesis was explored by visual analysis, and the intracellular free pathway enzymes Fni, IspA, HepT and YuxO were localized to FMMs through FloA to achieve the compartmentalization of MK-7 synthesis pathway. Finally, a high MK-7 production strain BS3AT was successfully obtained. The production of MK-7 reached 300.3 mg/L in shake flask and 464.2 mg/L in 3 L fermenter.

A CT-based radiomics nomogram for differentiating ovarian cystadenomas and endometriotic cysts

AIM

To construct and validate a computed tomography (CT)-based radiomics nomogram integrating radiomics signature and clinical factors to distinguish ovarian cystadenomas and endometriotic cysts.

MATERIALS AND METHODS

A total of 287 patients with ovarian cystadenomas (n=196) or endometriotic cysts (n=91) were divided randomly into a training cohort (n=200) and a validation cohort (n=87). Radiomics features based on the portal venous phase of CT images were extracted by PyRadiomics. The least absolute shrinkage and selection operation regression was applied to select the significant features and develop the radiomics signature. A radiomics score (rad-score) was calculated. The clinical model was built by the significant clinical factors. Multivariate logistic regression analysis was employed to construct the radiomics nomogram based on significant clinical factors and rad-score. The diagnostic performances of the radiomics nomogram, radiomics signature, and clinical model were evaluated and compared in the training and validation cohorts. Diagnostic confusion matrices of these models were calculated for the validation cohort and compared with those of the radiologists.

RESULTS

Seventeen radiomics features from CT images were used to build the radiomics signature. The radiomics nomogram incorporating cancer antigen 125 (CA-125) level and rad-score showed the best performance in both the training and validation cohorts with AUCs of 0.925 (95% confidence interval [CI]: 0.885-0.965), and 0.942 (95% CI: 0.891-0.993), respectively. The accuracy of radiomics nomogram in the confusion matrix outperformed the radiologists.

CONCLUSIONS

The radiomics nomogram performed well for differentiating ovarian cystadenomas and endometriotic cysts, and may help in clinical decision-making process.

Development of TaqMan-based real-time PCR assay based on the E1 genefor the quantitative detection of the Getah virus

To develop a sensitive, specific, and rapid approach for the detection Getah virus (GETV), a set of primers targeting the conserved region of the E1 gene was created. The TaqMan-based real-time PCR method for GETV detection was developed by optimizing the reaction conditions. The method demonstrated excellent specificity, and amplification did not occur with the causative agents of all prevalent swine viral infections (CSFV, PRRSV, PRV, PEDV, PTV, and JEV), except GETV. Additionally, upon assessing the sensitivity of the method, the minimum detection limit for GETV was found to be 5.94 copies/μL, which is 10 times higher than that of the traditional PCR approach. Further, the intra- and inter-assay variation coefficients were less than 1%, demonstrating good repeatability. Moreover, GETV was found in 10 of the 20 field serum samples using real-time PCR but only in three of the samples using traditional PCR. Consequently, the first GETV TaqMan-based real-time PCR approach based on the E1 gene was developed for GETV pathogenic diagnoses, and this exhibited high specificity, sensitivity, and repeatability. This assay is practical for the pathogenic diagnosis and epidemiology of GETV.

Utility of in vivo zebrafish cardiac assay to predict the functional impact of KCNQ1 variants

Background

Genetic testing for inherited arrhythmias and discriminating pathogenic from benign variants are integral for the gene-based medicine. However, the high throughput in vivo functional analysis for the rare variants of the KCNQ1 potassium channel is scarce.

Purpose

We tested the utility of the in vivo zebrafish cardiac assay for determining the pathogenicity of the KCNQ1 variants identified in patients with long QT syndrome (LQTS) and atrial fibrillation (AF).

Methods

We generated a knock-out zebrafish with CRISPR-mediated insertions or deletions of the KCNQ1 homolog in zebrafish (kcnq1+/+). To test the utility of the cardiac assay, we used five KCNQ1 variants identified in patients with LQTS or familial AF. Human wild-type or mutant KCNQ1 cRNA (Q1) was co-injected with human KCNE1 cRNA (E1) into the F3 generation embryos with homozygous deletions. We dissected the hearts from the thorax at 72 hour-post-fertilization and measured transmembrane potential in zebrafish heart using the disrupted patch technique. Action potential duration was calculated as the time interval between the peak maximum upstroke velocity and 90% of repolarization (APD90). We compared the APD90s with patients' clinical phenotype and IKs density measured by patch-clamp technique in heterologous system.

Results

The mean APD90 of embryos with kcnq1del/del was 279±48 ms, which was restored by injecting Q1 WT and E1 (159±29 ms) to that with kcnq1+/+ (167±28 ms). We tested if the mean APD90 of embryos with kcnq1del/del was restored (shortened) by injecting the KCNQ1 variants. First we tested the dominant negative variant p.S277L and the trafficking deficient variant p.T587M. Patients with these variants showed significant prolonged QT intervals, and patch clamp study showed both variants caused the non-functional channels. Zebrafish cardiac assay showed the mean APD90 of embryos with kcnq1del/del+ Q1 S277L+E1 or Q1 T587M+E1 was significantly longer than that with kcnq1del/del+Q1 WT+E1 (Table). Next we tested in-frame variant c.1472_1473 ins GGACCT, which was identified from a patient with AF and normal QT interval. Patch clamp study showed the current density of the mutant KCNQ1 channel with KCNE1 was comparable to that of wild-type KCNQ1 channel with KCNE1. Zebrafish assay showed the mean APD90 of embryos with kcnq1del/del shortened by injecting Q1 insACCTGG +E1 (Table). Finally we tested a missense variant p.R451Q, which was identified from a patient with LQTS. Patch clamp study showed the currents in the cells transfected with R451Q+KCNE1 were similar to those with WT+KCNE1. Zebrafish assay showed the mean APD90 of embryos with kcnq1del/del+Q1 R451Q+E1 was longer than that with kcnq1del/del+Q1 WT+E1 (Table).

Conclusions

Functional analysis of in vivo zebrafish cardiac assay might be useful for determining the pathogenicity of rare variants in patients with LQTS.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): The Grant-in-Aid for Scientific Research (C)

PSXI-11 Assessing in situ rumen degradability of late season kudzu (Pueraria montana var. lobata)

Kudzu (Pueraria montana var. lobata) is an invasive weed species native to eastern Asia affecting much of the southeastern United States. Its broad leaves and viny growth allow it to outcompete native plant species for sunlight and nutrients. Kudzu, however, is a leguminous plant, making it a potential feedstock for ruminant species. Browsing ruminants in areas affected by kudzu could benefit animal productivity while serving to ameliorate rapid plant growth. This study specifically sought to assess the overall rumen degradability, rate of digestion, digestible fraction, and indigestible fraction using an in situ methodology. In situ rumen degradability was analyzed using four ruminally fistulated steers as individual experimental units over two repeated trials. Samples were incubated at 1, 12, 24, 36, 48, 60, and 72 h. Kudzu used in these trials was collected during September, making analysis in this study a reflection of degradability toward the end of the growing season. Data were analyzed as a randomized complete block design with repeated measures showing no significant differences between steers or trials (P &gt; 0.05). Overall degradability across all steers and times was 69.79%. Significant changes in dry matter disappearance across all steers were observed at 1, 12, and 24 h (P &lt; 0.05) with values of 33.86, 64.78, and 74.26%, respectively, and highest observed degradability at 72 h (79.55%). Incubation times between 24 and 72 h were not used in determining rate of digestion as dry matter disappearances throughout these times were not significantly different (P &gt; 0.05). Rate of digestion (kd) was determined, using linear regression, to be 1.68% ∙ h-1 along with a digestible fraction (Do) of 28.29% and indigestible fraction (U) of 22.03%. The results of this study reflect that kudzu maintains a relatively high level of rumen degradability toward seasonal senescence, making it a functional feedstock even into the cooler months.

High urinary excretion rate of glucose attenuates serum uric acid level in type 2 diabetes with normal renal function

AIMS/INTRODUCTION

The relationship between urinary excretion rate of glucose (UEGL) and uric acid (UA) metabolism in adults with type 2 diabetes (T2D) remains unclear to date. This study aimed to investigate the relationships of UEGL with serum UA (SUA), urinary excretion rate of uric acid (UEUA), and renal clearance of uric acid (CLUA) in adults with T2D. We hypothesised that high UEGL increases UA excretion, which in turn leads to lower SUA.

MATERIALS AND METHODS

This was a cross-sectional study of 635 inpatients with T2D recruited between 2018 and 2019. The relationships of UEGL with UEUA, CLUA, and hyperuricaemia were assessed using analysis of covariance and multivariate regression analysis.

RESULTS

Patients in the higher quartile of UEGL tended to have lower SUA levels than those in the lower quartile. In contrast, patients in the higher quartile of UEGL tended to have higher CLUA (p for trend < 0.0001), and a similar trend was observed for UEUA. In adjusted multivariable linear regression model, UEGL was negatively correlated with SUA (β = - 0.023, 95% CI - 0.034 to - 0.013, p < 0.0001). However, positive correlations of UEGL with UEUA (β = 0.046, 95% CI 0.018-0.074, p = 0.001) and CLUA (β = 0.063, 95% CI 0.042-0.085, p < 0.0001) were found. Furthermore, consistent significant inverse associations were observed between quartiles of UEGL and hyperuricaemia in the adjusted multivariate logistic regression model.

CONCLUSIONS

A high UEGL level was positively correlated with UEUA and CLUA. Moreover, it was inversely associated with SUA level, and a consistently increased UEGL level reduced the risk of hyperuricaemia in patients with T2D.

[The enlightenment of foreign MD-MPH double degree program to the cultivation of high-level applied public health talents in China]

Objective: To understand the current status of foreign dual-degree programs of Medical Doctor (MD) and Master of Public Health (MPH) and provide evidence-based decision-making reference for promoting the education of high-level applied public health talents in China. Methods: The list of involved institutions and information of foreign MD-MPH dual-degree programs was collected through literature retrieval, online information searching, and additional survey of key figures. We extracted the details of each project regarding professional fields, core competence, length of schooling, teaching and learning arrangement, internship eligibility, and graduation assessment. Python 3.8.0 was used for data cleaning, and the occurrence frequency of related items in each dimension was calculated. Results: A total of 99 MD-MPH programs from 104 foreign institutions were included, among which 97.1% of them were implemented in universities from the United States. The School of Public Health provided 42.4% (42/99) of the programs. Epidemiology was the major discipline set up among most programs, accounting for 12.0% (29/241) of all the specialties involved. Epidemiological research methods, health policy management and practice, and public health practice were the top 3 core competencies to be mastered. Of the 99 programs, 87 gave information on the length of the program, of which 74.7% (65/87) were five years, 6.9% (6/87) were four years, and 18.4% (16/87) included both 4-year and 5-year programs. Conclusions: The international MD-MPH programs were sophisticated and mainly organized by the School of Public Health alone or in conjunction with the School of Medicine. Epidemiology is the core course and competence objective, with a length of 4-5 years. Through learning experience from international MD-MPH programs and the Chinese unique medical development background, China should optimize its medical education system to develop a suitable talent training strategy for MD-MPH dual-degree programs in the new era.

Multilayer Genetic Circuits for Dynamic Regulation of Metabolic Pathways

The dynamic regulation of metabolic pathways is based on changes in external signals and endogenous changes in gene expression levels and has extensive applications in the field of synthetic biology and metabolic engineering. However, achieving dynamic control is not trivial, and dynamic control is difficult to obtain using simple, single-level, control strategies because they are often affected by native regulatory networks. Therefore, synthetic biologists usually apply the concept of logic gates to build more complex and multilayer genetic circuits that can process various signals and direct the metabolic flux toward the synthesis of the molecules of interest. In this review, we first summarize the applications of dynamic regulatory systems and genetic circuits and then discuss how to design multilayer genetic circuits to achieve the optimal control of metabolic fluxes in living cells.

[Curcumin induces human lens epithelial cell apoptosis and cell cycle arrest by inhibiting Wnt/β-catenin signaling pathway]

OBJECTIVE

To investigate the effect of curcumin on cell cycle and apoptosis of human lens epithelial cells and the possible molecular mechanism.

OBJECTIVE

Cultured human lens epithelial cell line HLEC-SRA01/04 was treated with 20, 40 and 60 μmol/L curcumin for 24 or 48 h. The cell proliferation inhibition rate was determined using MTT assay, and the changes in cell cycle, mitochondrial membrane potential and apoptosis rate were analyzed with flow cytometry. Western blotting was used to detect the expression levels of caspase-9, caspase-3, Bcl-2, Bax, cyclin B1, CDK1, β-catenin, c-myc, and cyclin D1 in the cells.

OBJECTIVE

Curcumin concentration- and time-dependently inhibited the proliferation of in HLEC-SRA01/04 cells as compared with the control cells (P < .05). Flow cytometric analysis showed that curcumin significantly increased apoptosis rate and cell percentage in G2/M phase and lowered mitochondrial membrane potential of HLEC-SRA01/04 cells in a concentrationdependent manner (P < 0.05). The results of Western blotting showed that curcumin also concentration-dependently increased the cellular expressions of caspase-3, caspase-9 and Bax and lowered the expressions of Bcl-2, cyclin B1, CDK1 and β-catenin along with the downstream proteins cyclin D1 and c-myc in the Wnt/β-catenin signaling pathway (P < 0.05).

OBJECTIVE

Curcumin inhibits the proliferation of HLEC-SRA01/04 cells possibly by inhibiting the Wnt/β-catenin signaling pathway and causing cell cycle arrest to induce cell apoptosis.

[Strategies and tools for metabolic engineering in Bacillus subtilis]

As a typical food safety industrial model strain, Bacillus subtilis has been widely used in the field of metabolic engineering due to its non-pathogenicity, strong ability of extracellular protein secretion and no obvious codon preference. In recent years, with the rapid development of molecular biology and genetic engineering technology, a variety of research strategies and tools have been used to construct B. subtilis chassis cells for efficient synthesis of biological products. This review introduces the research progress of B. subtilis from the aspects of promoter engineering, gene editing, genetic circuit, cofactor engineering and pathway enzyme assembly. Then, we also summarized the application of B. subtilis in the production of biological products. Finally, the future research directions of B. subtilis are prospected.

Mechanisms of primary and acquired resistance to PD-1/PD-L1 blockade and the emerging role of gut microbiome

As a very promising immunotherapy, PD-1/PD-L1 blockade has revolutionized the treatment of a variety of tumor types, resulting in significant clinical efficacy and lasting responses. However, these therapies do not work for a large proportion of patients initially, which is called primary resistance. And more frustrating is that most patients eventually develop acquired resistance after an initial response to PD-1/PD-L1 blockade. The mechanisms that lead to primary and acquired resistance to PD-1/PD-L1 inhibition have remained largely unclear. Recently, the gut microbiome has emerged as a potential regulator for PD-1/PD-L1 blockade. This review elaborates on the current understanding of the mechanisms in terms of PD-1 related signaling pathways and necessary factors. Moreover, this review discusses new strategies to increase the efficacy of immunotherapy from the perspectives of immune markers and gut microbiome.

Engineering a ComA Quorum-Sensing circuit to dynamically control the production of Menaquinone-4 in Bacillus subtilis

Menaquinone-4 (MK-4) plays a significant role in bone health and cardiovascular therapy. Although many strategies have been adopted to increase the yield of MK-4 in Bacillus subtilis 168, the effectiveness of MK-4 is still low due to the inherent limitations of metabolic pathways. However, dynamic regulation based on quorum sensing (QS) has been extensively applied as a fundamental tool for fine-tuning gene expression in reaction to changes in cell density without adding expensive inducers. Nevertheless, in most reports, QS systems depend on down-regulated expression rather than up-regulated expression, which greatly limit their potential as molecular switches to control metabolic flux. To address this challenge, a modular PhrQ-RapQ-ComA QS system is developed based on promoter P_A11, which is up-regulated by phosphorylated ComA (ComA-P). In this paper, firstly we analyzed the ComA-based gene expression regulation system in Bacillus subtilis 168. We constructed a promoter library of diff ;erent abilities, selected best promoters from a library, and performed mutation screening on the selected promoters. Furthermore, we constructed a PhrQ-RapQ-ComA QS system to dynamically control the synthesis of MK-4 in B. subtilis 168. Cell growth and efficient synthesis of the target product can be dynamically balanced by the QS system. Our dynamic adjustment approach increased the yield of MK-4 in shake flask from 120.1 ± 0.6 to 178.9 ± 2.8 mg/L, and reached 217 ± 4.1 mg/L in a 3-L bioreactor, which verified the effectiveness of this strategy. In summary, PhrQ-RapQ-ComA QS system can realize dynamic pathway regulation in B. subtilis 168, which can be stretched to a great deal of microorganisms to fine-tune gene expression and enhance the production of metabolites.

HSP70 inhibits pig pituitary gonadotrophin synthesis and secretion by regulating the corticotropin-releasing hormone signaling pathway and targeting SMAD3

High levels or long periods of stress have been shown to negatively impact cell homeostasis, including with respect to abnormalities in domestic animal reproduction, which are typically activated through the hypothalamus-pituitary-adrenal axis, in which corticotropin-releasing hormone (CRH) and heat shock protein 70 (HSP70) are involved. In addition, CRH has been reported to inhibit pituitary gonadotrophin synthesis, and HSP70 is expressed in the pituitary gland. The aim of this study was to determine whether HSP70 was involved in regulating gonadotrophin synthesis and secretion by mediating the CRH pathway in the porcine pituitary gland. Our results showed that HSP70 was highly expressed in the porcine pituitary gland, with over 90% of gonadotrophic cells testing HSP70 positive. The results of functional studies demonstrated that the HSP70 inducer decreased FSH and LH levels in cultured porcine primary pituitary cells, whereas an HSP70 inhibitor blocked the negative effect of CRH on gonadotrophin synthesis and secretion. Furthermore, our results demonstrated that HSP70 inhibited gonadotrophin synthesis and secretion by blocking GnRH-induced SMAD3 phosphorylation, which acts as the targeting molecule of HSP70, while CRH upregulated HSP70 expression through the PKC and ERK pathways. Collectively, these data demonstrate that HSP70 inhibits pituitary gonadotrophin synthesis and secretion by regulating the CRH signaling pathway and inhibiting SMAD3 phosphorylation, which are important for our understanding the mechanisms of the stress affects domestic animal reproductive functions.

Efficacy of utidelone plus capecitabine versus capecitabine for heavily pretreated, anthracycline- and taxane-refractory metastatic breast cancer: final analysis of overall survival in a phase III randomised controlled trial

BACKGROUND

Primary analysis of the phase III trial BG01-1323L demonstrated that utidelone plus capecitabine significantly improved progression-free survival (PFS) and overall response rate (ORR) versus capecitabine alone in heavily-pretreated patients with metastatic breast cancer (MBC). Here, we report the final overall survival (OS) analysis and updates of other endpoints.

PATIENTS AND METHODS

In total, 405 patients were randomised 2:1 to receive utidelone (30 mg/m² IV daily, days 1-5, over 90 min) plus capecitabine (1000 mg/m² orally b.i.d., days 1-14) or capecitabine alone (1250 mg/m² orally b.i.d., days 1-14) every 21 days. The secondary endpoint, OS, was estimated using the Kaplan-Meier product-limit approach at a two-sided alpha level of 0.05 after the prespecified 310 death events had been reached. Exploratory analyses of the primary endpoint, PFS, and the secondary endpoint, ORR, were also done. Safety was analysed in patients who had at least one dose of study drug.

RESULTS

At the final OS analysis, the median duration of follow-up was 19.6 months in the utidelone plus capecitabine group and 15.4 months in the capecitabine alone group. In the intention-to-treat population, 313 deaths had occurred at data cut-off, 203 of 270 patients in the combination group and 110 of 135 in the monotherapy group. Median OS in the combination group was 19.8 months compared with 16.0 months in the monotherapy group [hazard ratio (HR) = 0.75, 95% confidence intervals (CI) 0.59-0.94, P = 0.0142]. The updated analysis of PFS and ORR showed that the combination therapy remained superior to monotherapy. Safety results were similar to those previously reported with respect to incidence, severity and specificity. No late-emerging toxicities or new safety concerns occurred.

CONCLUSIONS

For heavily-pretreated, anthracycline- and taxane-resistant MBC patients, utidelone plus capecitabine significantly improved OS versus capecitabine alone. These results support the use of utidelone plus capecitabine as a novel therapeutic regimen for patients with MBC.

THU0243 HSA_CIRC_0123190 FUNCTIONS AS A COMPETITIVE ENDOGENOUS RNA TO REGULATE APLNR EXPRESSION BY SPONGING HSA-MIR-483-3P IN LUPUS NEPHRITIS

Background:

Lupus nephritis (LN) is one of the most severe complications of systemic lupus erythematosus (SLE). Circular RNAs(circRNAs) can act as competitive endogenous RNAs (ceRNAs) to regulate gene transcription, which is involved in mechanism of many diseases, such as, autoimmunity diseases. However, the role of circRNA in lupus nephritis has been rarely reported.

Objectives:

In this study, we aim to investigate the clinical value of circRNAs and explore the mechanism of circRNA involvement in the pathogenesis of LN.

Methods:

Renal tissues from three untreated LN patients and three normal controls (NCs) were used to identify differently expressed circRNAs by RNA sequencing (RNA-seq). Validated assays were used by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Correlation analysis and receiver operating characteristic (ROC) curve were used to reveal the clinical value of selected circRNA, miRNA and mRNA. The interactions between circRNA and miRNA, or miRNA and mRNA were further determined by luciferase reporter assay. The degrees of renal fibrosis between the two groups were compared by Masson-trichome staining and immunohistochemistry staining.

Results:

159 circRNAs were significantly dysregulated in LN patients compared with NC group. The expression of hsa_circ_0123190 was significantly decreased in renal tissues of patients with LN (p=0.014), as same as the sequencing results. The area under the ROC curve of hsa_circ_0123190 in renal tissues was 0.820. Bio-informatic analysis and luciferase reporter assay illustrated that hsa_circ_0123190 can act as a sponge for hsa-miR-483-3p which was also validated to interact with APLNR mRNA. APLNR mRNA expression was positively related with chronicity index (CI) of LN (R2=0.452,p=0.033). Finally, the factors of renal fibrosis, especially TGF-β (p=0.018), were more pronounced in the LN group.

Conclusion:

Hsa_circ_0123190 could function as a ceRNA to regulate APLNR expression involved in renal fibrosis by sponging hsa-miR-483-3p in LN

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Disclosure of Interests:

None declared

Combinatorial Methylerythritol Phosphate Pathway Engineering and Process Optimization for Increased Menaquinone-7 Synthesis in Bacillus subtilis

Vitamin K2 (menaquinone) is an essential vitamin existing in the daily diet, and menaquinone-7 (MK-7) is an important form of it. In a recent work, we engineered the synthesis modules of MK-7 in Bacillus subtilis, and the strain BS20 could produce 360 mg/l MK-7 in shake flasks, while the methylerythritol phosphate (MEP) pathway, which provides the precursor isopentenyl diphosphate for MK-7 synthesis, was not engineered. In this study, we overexpressed five genes of the MEP pathway in BS20 and finally obtained a strain (BS20DFHG) with MK-7 titer of 415 mg/l in shake flasks. Next, we optimized the fermentation process parameters (initial pH, temperature and aeration) in an 8-unit parallel bioreactor system consisting of 300-ml glass vessels. Based on this, we scaled up the MK-7 production by the strain BS20DFHG in a 50-l bioreactor, and the highest MK-7 titer reached 242 mg/l. Here, we show that the engineered strain BS20DFHG may be used for the industrial production of MK-7 in the future.

Enzyme Assembly for Compartmentalized Metabolic Flux Control

Enzyme assembly by ligand binding or physically sequestrating enzymes, substrates, or metabolites into isolated compartments can bring key molecules closer to enhance the flux of a metabolic pathway. The emergence of enzyme assembly has provided both opportunities and challenges for metabolic engineering. At present, with the development of synthetic biology and systems biology, a variety of enzyme assembly strategies have been proposed, from the initial direct enzyme fusion to scaffold-free assembly, as well as artificial scaffolds, such as nucleic acid/protein scaffolds, and even some more complex physical compartments. These assembly strategies have been explored and applied to the synthesis of various important bio-based products, and have achieved different degrees of success. Despite some achievements, enzyme assembly, especially in vivo, still has many problems that have attracted significant attention from researchers. Here, we focus on some selected examples to review recent research on scaffold-free strategies, synthetic artificial scaffolds, and physical compartments for enzyme assembly or pathway sequestration, and we discuss their notable advances. In addition, the potential applications and challenges in the applications are highlighted.

Enzyme assembly guided by SPFH-induced functional inclusion bodies for enhanced cascade biocatalysis

Enzyme clustering into compact agglomerates could accelerate the processing of intermediates to enhance metabolic pathway flux. However, enzyme clustering is still a challenging task due to the lack of universal assembly strategy applicable to all enzymes. Therefore, we proposed an alternative enzyme assembly strategy based on functional inclusion bodies. First, functional inclusion bodies in cells were formed by the fusion expression of stomatin/prohibitin/flotillin/HflK/C (SPFH) domain and enhanced green fluorescent protein, as observed visually and by transmission electron microscopy. The formation of SPFH-induced functional inclusion bodies enhanced intermolecular polymerization as revealed by further analysis combined with Förster resonance energy transfer and bimolecular fluorescent complimentary. Finally, the functional inclusion bodies significantly improved the enzymatic catalysis in living cells, as proven by the examples with whole-cell biocatalysis of phenyllactic acid by Escherichia coli, and the production of N-acetylglucosamine by Bacillus subtilis. Our findings suggest that SPFH-induced functional inclusion bodies can enhance the cascade reaction of enzymes, to serve as a potential universal strategy for the construction of efficient microbial cell factories.

Identification and Characterization of a Cellodextrin Transporter in Aspergillus niger

Aspergillus niger produces a wide spectrum of extracellular polysaccharide hydrolases that hydrolyze cellulose into soluble glucose and cellodextrins. Transporters are essential for sugar uptake, yet it is not clear whether cellodextrin transporters exist in A. niger. Here, one cellulose inducible cellodextrin transporter CtA was identified in A. niger B2. It was found that CtA not only could transport cellobiose, but also cellotriose, cellotetraose, and cellopentaose. The yeast strain YPβG-CtA, expressing cellodextrin transporter CtA and an intracellular β-glucosidase, grew on cellobiose with the cell growth rate of 0.0830 ± 0.0113 h^–1 under aerobic condition. Furthermore, the engineered yeast could produce 1.1 g/L ethanol anaerobically on cellobiose in 2 days. The identification of CtA provides evidence that the cellodextrin uptake is a complementary strategy of cellulose utilization in A. niger, and the CtA could be a strong transporter candidate for constructing engineered cellodextrin-utilizing microorganisms.

Effects of early nutritional intervention on oral mucositis in patients with radiotherapy for head and neck cancer

BACKGROUND

To observe the effect of early nutritional intervention on radiation-induced oral mucositis and nutritional status in patients with head and neck cancer (HNC).

METHODS

A total of 54 HNC patients were divided into early (28 cases) and late (26 cases) nutritional intervention groups. The early group received enteral nutrition at the beginning of radiotherapy (RT), while the late group received enteral nutrition after restricted feeding. Operators reported and assessed the timing and extent of oral mucositis and nutritional status during treatment. The nutritional status assessment indicators included body weight; body mass index (BMI); Patient-Generated-Subjective Global Assessment (PG-SGA) score; levels of albumin, hemoglobin and pre-albumin and total lymphocyte count.

RESULTS

The incidence of high-grade oral mucositis was significantly lower in the early group than that in the late group (P < 0.05). Nutritional status assessments showed more significant weight and BMI losses in the late group than in the early group at weeks 4 and 7 after RT (P < 0.01). The albumin decreased in the late group at week 7 after RT was more significant than that in the early group (P < 0.05). Albumin, hemoglobin and pre-albumin levels and total lymphocyte count decreased significantly in both groups (P > 0.05). During therapy, more patients in the early group were well-nourished and fewer were malnourished according to PG-SGA scores (P < 0.05).

CONCLUSION

Early nutritional intervention can reduce the incidence of high-grade oral mucositis during RT in patients with HNC and improve the nutritional status during treatment, which has important clinical significance.

Determination of Total Dietary Fiber (CODEX Definition) by Enzymatic-Gravimetric Method and Liquid Chromatography: Collaborative Study

A method for the determination of total dietary fiber (TDF), as defined by the CODEX Alimentarius, was validated in foods. Based upon the principles of AOAC Official MethodsSM 985.29, 991.43, 2001.03, and 2002.02, the method quantitates high- and low-molecular-weight dietary fiber (HMWDF and LMWDF, respectively). In 2007, McCleary described a method of extended enzymatic digestion at 37C to simulate human intestinal digestion followed by gravimetric isolation and quantitation of HMWDF and the use of LC to quantitate low-molecular-weight soluble dietary fiber (LMWSDF). The method thus quantitates the complete range of dietary fiber components from resistant starch (by utilizing the digestion conditions of AOAC Method 2002.02) to digestion resistant oligosaccharides (by incorporating the deionization and LC procedures of AOAC Method 2001.03). The method was evaluated through an AOAC collaborative study. Eighteen laboratories participated with 16 laboratories returning valid assay data for 16 test portions (eight blind duplicates) consisting of samples with a range of traditional dietary fiber, resistant starch, and nondigestible oligosaccharides. The dietary fiber content of the eight test pairs ranged from 11.57 to 47.83. Digestion of samples under the conditions of AOAC Method 2002.02 followed by the isolation and gravimetric procedures of AOAC Methods 985.29 and 991.43 results in quantitation of HMWDF. The filtrate from the quantitation of HMWDF is concentrated, deionized, concentrated again, and analyzed by LC to determine the LMWSDF, i.e., all nondigestible oligosaccharides of degree of polymerization 3. TDF is calculated as the sum of HMWDF and LMWSDF. Repeatability standard deviations (sr) ranged from 0.41 to 1.43, and reproducibility standard deviations (sR) ranged from 1.18 to 5.44. These results are comparable to other official dietary fiber methods, and the method is recommended for adoption as Official First Action.

[The expression of VHL/HIF signaling pathway in the erythroid progenitor cells with chronic mountain sickness]

Objective: To investigate the expression and interaction of VHL/HIF-α pathways including HIF-1α, HIF-2α as well as VHL in erythroid progenitor cells of bone marrow from chronic mountain sickness (CMS) patients. Methods: A total of 25 patients with CMS and 21 healthy controls were recruited for this study. The CD71(+)CD235a(+) cells in bone marrow mononuclear cells, marked as erythroid progenitor cells, were isolated using MACS separation technology. The expression levels of HIF-1α, HIF-2α and VHL in erythroid progenitor cells were detected by Western blotting and real-time fluorescence quantitative PCR. Results: The mRNA levels of HIF-2α were higher in erythroid progenitor cells of CMS than in healthy controls [1.68 (0.81, 2.22) vs 0.98 (0.60, 1.19), P<0.05], while HIF-1α and VHL mRNA levels were similar between the two groups (P>0.05). Spearman analyses indicated that HIF-2α mRNA was positively associated with hemoglobin (Hb) levels in the erythroid progenitor cells of CMS (ρ=0.504, P<0.05). Furthermore, the mRNA level of HIF-2α was correlated with the mRNA level of VHL in the erythroid progenitor cells of CMS (ρ=0.647, P<0.05).The protein levels of HIF-2α in the erythroid progenitor cells of CMS were higher than that of healthy controls [0.94(0.68, 3.30) vs 0.59(0.30, 0.88), P<0.05], but the protein levels of HIF-1α and VHL were similar between the two groups (P>0.05). Conclusions: The abnormal increased expression of HIF-2α in the erythroid progenitor cells of CMS patients leads to the abnormal expression of hypoxia sensitive genes downstream, participating in the occurrence and development of CMS.

Engineering a Bifunctional Phr60-Rap60-Spo0A Quorum-Sensing Molecular Switch for Dynamic Fine-Tuning of Menaquinone-7 Synthesis in Bacillus subtilis

Quorum sensing (QS)-based dynamic regulation has been widely used as basic tool for fine-tuning gene expression in response to cell density changes without adding expensive inducers. However, most reported QS systems primarily relied on down-regulation rather than up-regulation of gene expression, significantly limiting its potential as a molecular switch to control metabolic flux. To solve this challenge, we developed a bifunctional and modular Phr60-Rap60-Spo0A QS system, based on two native promoters, P_abrB (down-regulation by Spo0A-P) and P_spoiiA (up-regulation by Spo0A-P). We constructed a library of promoters with different capacities to implement down-regulation and up-regulation by changing the location, number, and sequences of the binding sites for Spo0A-P. The QS system can dynamically balance the relationship between efficient synthesis of the target product and cell growth. Finally, we validated the usefulness of this strategy by dynamic control of menaquinone-7 (MK-7) synthesis in Bacillus subtilis 168, a model Gram-positive bacterium, with the bifunctional Phr60-Rap60-Spo0A quorum sensing system. Our dynamic pathway regulation led to a 40-fold improvement of MK-7 production from 9 to 360 mg/L in shake flasks and 200 mg/L in 15-L bioreactor. Taken together, our bilayer QS system has been successfully integrated with biocatalytic functions to achieve dynamic pathway regulation in B. subtilis 168, which may be extended for use in other microbes to fine-tune gene expression and improve metabolites production.

Abstract P6-17-17: Pertuzumab, trastuzumab, and docetaxel for HER2-positive early or locally advanced breast cancer in the neoadjuvant setting: Efficacy and safety analysis of a randomized phase III study in Asian patients (PEONY)

Background

Pertuzumab and trastuzumab (P and H; F. Hoffmann-La Roche Ltd, Basel, CH) bind to distinct HER2 subdomains and have complementary modes of anticancer activity in HER2-positive breast cancer (BC). A global Phase II study (NeoSphere) reported that neoadjuvant treatment with P+H+docetaxel (D) significantly increased breast pathologic complete response (bpCR) vs H+D in patients (pts) with early/locally advanced/inflammatory HER2-positive BC (Gianni et al. Lancet Oncol 2012). PEONY (NCT02586025), a randomized, multicenter, double-blind, placebo-controlled, Phase III trial conducted in an Asian population (mainland China, Taiwan, Korea, Thailand), primarily compared the efficacy, safety, and tolerability of P+H+D vs placebo (Pla)+H+D in the neoadjuvant setting. We present data from the primary analysis.

Methods

Pts with centrally confirmed HER2-positive early (T2–3, N0–1)/locally advanced (T2–3, N2 or N3; T4, any N) BC were randomized 2:1 to 4 cycles of P+H+D or Pla+H+D every 3 weeks, before surgery: P, 840 mg loading/420 mg maintenance doses (or Pla); H, 8 mg/kg loading/6 mg/kg maintenance; D, 75 mg/m2. Post-surgery, pts received 3 cycles of fluorouracil, epirubicin, and cyclophosphamide followed by 13 cycles of P+H or Pla+H for up to 1 year (total of 17 HER2-targeted therapy cycles). The primary endpoint was total pCR rate (tpCR; absence of any residual invasive cancer in the breast and lymph nodes [ypT0/is, ypN0]) assessed by independent review committee (IRC) when pts completed surgery with a tpCR assessment. Missing/invalid assessments were considered residual disease.

Results

A total of 329 pts were randomized: 219 to P, 110 to Pla. Baseline characteristics were well balanced. Most pts had early BC (69.6%) and were from mainland China (79.3%). In the intention-to-treat population, the tpCR rate by IRC was 39.3% in the P arm and 21.8% in the Pla arm; a clinically and statistically significant difference of 17.5% (95% CI 6.9–28.0; p=0.0014). The local pathologist-assessed tpCR rates were 39.3% and 20.9%, respectively. A consistent treatment benefit of P vs Pla was observed in subgroups. Incidences of grade ≥3 adverse events (Aes) were 48.6% in the P arm and 41.8% in the Pla arm. Of the most common grade 3 Aes (≥3% of pts), neutropenia was higher in the P arm (38.1% vs 32.7%). Of the most common any-grade Aes (≥5%), diarrhea was higher in the P arm (38.5% vs 16.4%). No heart failure (New York Heart Association Functional Classification III or IV) or significant left ventricular ejection fraction decline events (≥10 percentage points from baseline and to &lt;50%) were observed during neoadjuvant therapy.

Conclusions

PEONY met its primary endpoint: P+H+D resulted in a clinically meaningful and statistically significant improvement in the tpCR rate by IRC vs Pla+H+D for the neoadjuvant treatment of HER2-positive early/locally advanced BC in Asian pts. Safety data were in line with the known P safety profile and generally comparable between treatment arms. Results were similar to NeoSphere, and confirm that P+H+D provides superior anticancer activity to H+D alone.

Citation Format: Shao Z, Pang D, Yang H, Li W, Wang S, Cui S, Liao N, Wang Y, Wang C, Chang Y-C, Wang H, Kang SY, Jiang Z, Li J, Zhou J, Althaus B, Mao Y, Eng-Wong J. Pertuzumab, trastuzumab, and docetaxel for HER2-positive early or locally advanced breast cancer in the neoadjuvant setting: Efficacy and safety analysis of a randomized phase III study in Asian patients (PEONY) [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 P6-17-17.

[Technical specification for clinical application of critical ultrasonography]

Critical ultrasonography(CUS) is different from the traditional diagnostic ultrasound, the examiner and interpreter of the image are critical care medicine physicians. The core content of CUS is to evaluate the pathophysiological changes of organs and systems and etiology changes. With the idea of critical care medicine as the soul, it can integrate the above information and clinical information, bedside real-time diagnosis and titration treatment, and evaluate the therapeutic effect so as to improve the outcome. CUS is a traditional technique which is applied as a new application method. The consensus of experts on critical ultrasonography in China released in 2016 put forward consensus suggestions on the concept, implementation and application of CUS. It should be further emphasized that the accurate and objective assessment and implementation of CUS requires the standardization of ultrasound image acquisition and the need to establish a CUS procedure. At the same time, the standardized training for CUS accepted by critical care medicine physicians requires the application of technical specifications, and the establishment of technical specifications is the basis for the quality control and continuous improvement of CUS. Chinese Critical Ultrasound Study Group and Critical Hemodynamic Therapy Collabration Group, based on the rich experience of clinical practice in critical care and research, combined with the essence of CUS, to learn the traditional ultrasonic essence, established the clinical application technical specifications of CUS, including in five parts: basic view and relevant indicators to obtain in CUS; basic norms for viscera organ assessment and special assessment; standardized processes and systematic inspection programs; examples of CUS applications; CUS training and the application of qualification certification. The establishment of applied technology standard is helpful for standardized training and clinical correct implementation. It is helpful for clinical evaluation and correct guidance treatment, and is also helpful for quality control and continuous improvement of CUS application.

[The expressions of VEGF and VEGFR signaling pathway in the bone marrow mononuclear cells with chronic mountain sickness]

Objective: This study was aimed at investigating the levels and relationships of vascular endothelial growth factor (VEGF) and its receptor(VEGFR) in the bone marrow mononuclear cells (MNC) of chronic mountain sickness (CMS). Methods: A total of 34 patients with CMS and 30 controls residing at altitudes of 3 000-4 500 m were recruited for this study. The levels of VEGF, VEGFR1 and VEGFR2 in bone marrow MNC were detected by flow cytometry technique and RT-qPCR. Results: The percentage of VEGFR2 positive cells in the bone marrow MNC of CMS were higher than that of the controls[20.7% (8.1%, 67.6%) vs 8.1% (2.2%, 14.9%), P<0.05], but that of VEGFR1-positive and VEGF-positive were similar in CMS and controls. The mRNA levels of VEGFR2 were higher in the bone marrow MNC of CMS than in the controls[1.7(1.0, 5.1) vs 1.0(0.4, 2.7), P<0.05], while VEGF and VEGFR1 mRNA levels were similar between the two groups. The percentage of VEGFR2 positive cells in CMS were significantly correlated with hemoglobin (r=0.453, P=0.007) and the percentage of VEGF-positive cells (r=0.373, P=0.030). Conclusions: Bone marrow MNC of CMS may show enhanced activity of the VEGF-VEGFR2 pathway, and it appears to be involved in the pathogenesis of CMS.

[Value of evaluating the coronary collateral circulation by transluminal attenuation gradient in patients with chronic total occlusion and related influencing factors]

Objective: To observe the value of evaluating the coronary collateral circulation of chronic total occlusion (CTO) by transluminal attenuation gradient (TAG) and Rentrop grading, and analyze the influencing factors for coronary collateral circulation. Methods: A total of 179 CTO patients admitted to Beijing Anzhen hospital during June 2013 to August 2016 were included in this study.All patients received coronary computed tomographic angiography (CCTA) examination before coronary angiography.Finally, 75 patients (79 vessels) were enrolled.Patients were divided into two groups on the basis of Rentrop classification.The Rentrop 3 was defined as a well-developed coronary collateral circulation group, including 50 CTO vessels, Rentrop 2 or below was defined as poorly-developed collateral circulation group, including 29 vessels.TAG values in patients with various Rentrop grades were analyzed.Univariate and multivariate analysis were used to determine the predictors of collateral circulation. Results: TAG increased consistently in proportion to the angiographic extent of collateral flow (TAG was (-33.6±24.4), (-16.5±15.7) and (-12.8±15.8) HU/10 mm in patients with Rentrop grade 0 or 1, 2 and 3, respectively, P=0.007). Number of good collateral circulation vessels predicted by TAG≥15.6 HU/10 mm was 45(57.0%, 45/79), and 50 (63.3%, 50/79) by Rentrop grade (P=0.383). Prevalence of diabetes was significantly lower (20.8%(10/48) vs. 48.1%(13/27), P=0.01), while history of previous myocardial infarction (MI) was significantly higher (35.4%(17/48) vs. 11.1%(3/27), P=0.02) in patients with good collateral circulation than in patients with poor collateral circulation.The TAG of the good collateral circulation group was significantly higher than in poorly collateral circulation group ((-12.8±15.8) HU/10 mm vs. (-21.2±19.6) HU/10mm, P=0.041). Multiple logistic regression analysis revealed that history of MI (OR=0.196, 95%CI 0.041-0.936, P=0.041) and diabetes(OR=6.604, 95%CI 1.726-25.274, P=0.006) were independent predictors of coronary collateral circulation. Conclusions: TAG could be used to evaluate status of coronary collateral circulation.Presence of MI history and absence of diabetes history are the two independent predictors of well-developed coronary collateral circulation in CTO patients.