Effect of Biofilm Forming on the Migration of Di(2-ethylhexyl)phthalate from PVC Plastics

Plastic additives, represented by plasticizers, are important components of plastic pollution. Biofilms inevitably form on plastic surfaces when plastic enters the aqueous environment. However, little is known about the effect of biofilms on plastic surfaces on the release of additives therein. In this study, PVC plastics with different levels of di(2-ethylhexyl)phthalate (DEHP) content were investigated to study the effect of biofilm growth on DEHP release. The presence of biofilms promoted the migration of DEHP from PVC plastics to the external environment. Relative to biofilm-free controls, although the presence of surface biofilm resulted in 0.8 to 11.6 times lower DEHP concentrations in water, the concentrations of the degradation product, monoethylhexyl phthalate (MEHP) in water, were 2.3 to 57.3 times higher. When the total release amounts of DEHP in the biofilm and in the water were combined, they were increased by 0.6-73 times after biofilm growth. However, most of the released DEHP was adsorbed in the biofilms and was subsequently degraded. The results of this study suggest that the biofilm as a new interface between plastics and the surrounding environment can affect the transport and transformation of plastic additives in the environment through barrier, adsorption, and degradation. Future research endeavors should aim to explore the transport dynamics and fate of plastic additives under various biofilm compositions as well as evaluate the ecological risks associated with their enrichment by biofilms.

Progressive abdominal pain with acute exacerbation due to retroperitoneal follicular dendritic cell sarcoma: a case report with targeted genomic sequencing analysis

BACKGROUND

Follicular dendritic cell sarcoma (FDCS) is a rare malignancy that arises from follicular dendritic cells and typically presents as a slow-growing painless mass without specific symptoms. Here we report an unusual case of a 55-year-old female with retroperitoneal FDCS who presented with progressive abdominal pain onset and acute exacerbation.

METHODS

On CTA, a middle-upper abdominal mass (58*40 mm) was shown with multiple enlarged lymph nodes. After en-bloc resection of the tumor, the patient recovered completely from her symptoms and was discharged without complication. One month later, the patient returned for follow-up and the relevant tests were completed.

RESULTS

In this case, CA724 elevated significantly and seemed to be associated with tumor progression. The results of positron emission tomography/computed tomography (PET/CT) and radiological examinations, including magnetic resonance imaging (MRI) and computed tomography angiography (CTA), were discussed to improve our understanding of diagnostic tools on FDCS. Targeted genomic sequencing analysis revealed three novel gene mutations, EPHA3 (nonsense mutation), DDR2 (SNV), and BIRC3 (InDel).

CONCLUSION

We reported an unusual case of retroperitoneal FDCS with acute exacerbated abdominal pain. The interpretations of CA724, PET/CT, as well as imaging results deserve further investigation in FDCS. Genomic sequencing revealed three novel gene mutations in FDCS, including EPHA3 (nonsense mutation), DDR2 (SNV), and BIRC3 (InDel).

Phthalates in plastic stationery in China and their exposure risks to school-aged children

Phthalates have been strictly banned in children's products in many countries. However, as a product with a high frequency of daily contact with children, stationery is not strictly regulated for phthalates in many countries and the occurrences and risks of phthalates in stationery are rarely reported. In this study, the contents of sixteen types of common phthalates in stationery were determined and the exposure risk of these phthalates to children was also estimated. The total contents of phthalates in all stationery ranged from 5.56 to 3.46 × 105 μg/g, with a median value of 1.48 × 104 μg/g. Polyvinyl chloride (PVC) desk mats (DMs) contained the highest contents of phthalates among all types of stationery. Percutaneous absorption and hand-to-mouth ingestion levels of phthalates for school-age children from the DMs were 2.03 × 10-5 - 10.14 μg/kg-Bw/day and 2.14 × 10-5 - 10.67 μg/kg-Bw/day, respectively. Di-2-ethylhexyl phthalate (DEHP) had the highest proportion, detection rate, and exposure level among all measured phthalates. Our study revealed that phthalates in PVC stationery, especially classroom DMs, at both contents and exposure risks, were higher than those in many other children's plastic products. It was necessary to strengthen the management of plastic stationery from the perspective of materials and phthalates addition.

AutoBar: Automatic Barrier Coverage Formation for Danger Keep Out Applications in Smart City

Barrier coverage is a fundamental application in wireless sensor networks, which are widely used for smart cities. In applications, the sensors form a barrier for the intruders and protect an area through intrusion detection. In this paper, we study a new branch of barrier coverage, namely warning barrier coverage (WBC). Different from the classic barrier coverage, WBC has the inverse protect direction, which moves the sensors surrounding a dangerous region and protects any unexpected visitors by warning them away from the dangers. WBC holds a promising prospect in many danger keep out applications for smart cities. For example, a WBC can enclose the debris area in the sea and alarm any approaching ships in order to avoid their damaging propellers. One special feature of WBC is that the target region is usually dangerous and its boundary is previously unknown. Hence, the scattered mobile nodes need to detect the boundary and form the barrier coverage themselves. It is challenging to form these distributed sensor nodes into a barrier because a node can sense only the local information and there is no global information of the unknown region or other nodes. To this end, in response to the newly proposed issue of the formation of barrier cover, we propose a novel solution AutoBar for mobile sensor nodes to automatically form a WBC for smart cities. Notably, this is the first work to trigger the coverage problem of the alarm barrier, wherein the regional information is not pre-known. To pursue the high coverage quality, we theoretically derive the optimal distribution pattern of sensor nodes using convex theory. Based on the analysis, we design a fully distributed algorithm that enables nodes to collaboratively move toward the optimal distribution pattern. In addition, AutoBar is able to reorganize the barrier even if any node is broken. To validate the feasibility of AutoBar, we develop the prototype of the specialized mobile node, which consists of two kinds of sensors: one for boundary detection and another for visitor detection. Based on the prototype, we conduct extensive real trace-driven simulations in various smart city scenarios. Performance results demonstrate that AutoBar outperforms the existing barrier coverage strategies in terms of coverage quality, formation duration, and communication overhead.

HUNK inhibits epithelial-mesenchymal transition of CRC via direct phosphorylation of GEF-H1 and activating RhoA/LIMK-1/CFL-1

Epithelial-mesenchymal transition (EMT) is associated with the invasive and metastatic phenotypes in colorectal cancer (CRC). However, the mechanisms underlying EMT in CRC are not completely understood. In this study, we find that HUNK inhibits EMT and metastasis of CRC cells via its substrate GEF-H1 in a kinase-dependent manner. Mechanistically, HUNK directly phosphorylates GEF-H1 at serine 645 (S645) site, which activates RhoA and consequently leads to a cascade of phosphorylation of LIMK-1/CFL-1, thereby stabilizing F-actin and inhibiting EMT. Clinically, the levels of both HUNK expression and phosphorylation S645 of GEH-H1 are not only downregulated in CRC tissues with metastasis compared with that without metastasis, but also positively correlated among these tissues. Our findings highlight the importance of HUNK kinase direct phosphorylation of GEF-H1 in regulation of EMT and metastasis of CRC.

Microbiota-derived tryptophan catabolites mediate the chemopreventive effects of statins on colorectal cancer

Epidemiological studies have indicated an association between statin use and reduced incidence of colorectal cancer (CRC), and work in preclinical models has demonstrated a potential chemopreventive effect. Statins are also associated with reduced dysbiosis in the gut microbiome, yet the role of the gut microbiome in the protective effect of statins in CRC is unclear. Here we validated the chemopreventive role of statins by retrospectively analysing a cohort of patients who underwent colonoscopies. This was confirmed in preclinical models and patient cohorts, and we found that reduced tumour burden was partly due to statin modulation of the gut microbiota. Specifically, the gut commensal Lactobacillus reuteri was increased as a result of increased microbial tryptophan availability in the gut after atorvastatin treatment. Our in vivo studies further revealed that L. reuteri administration suppressed colorectal tumorigenesis via the tryptophan catabolite, indole-3-lactic acid (ILA). ILA exerted anti-tumorigenic effects by downregulating the IL-17 signalling pathway. This microbial metabolite inhibited T helper 17 cell differentiation by targeting the nuclear receptor, RAR-related orphan receptor γt (RORγt). Together, our study provides insights into an anti-cancer mechanism driven by statin use and suggests that interventions with L. reuteri or ILA could complement chemoprevention strategies for CRC.

Delivery of LINC00589 via mesoporous silica nanoparticles inhibits peritoneal metastasis in gastric cancer

Peritoneal metastasis is one of the common forms of metastasis in gastric cancer (GC). In this study, we identified the expression pattern of LINC00589 in GC patients and investigate the biological function in GC cells. RNA-pulldown assay was performed to explore the underlying molecular mechanism. Further, we utilize polyethyleneimine-modified mesoporous silica nanoparticles (PMSNs) as the nanocarriers for delivery of LINC00589 encoding plasmid and tested its therapeutic potential for GC with peritoneal dissemination. We revealed that LINC00589 was downregulated in GC tissues and suppressed the metastatic ability of GC cells. Mechanistically, LINC00589 exerted tumor suppressive function by promoting hnRNPA1 protein ubiquitination and proteasomal degradation, thus blocking alternative splicing of PKM to PKM2. Furthermore, LINC00589 delivered by PMSNs could suppress the peritoneal metastasis of GC in vivo and in vitro. This work may provide a new treatment option in GC peritoneal metastasis.

Transferability and reproducibility of the EpiSkin™ Micronucleus Assay

A novel in vitro 3D micronucleus assay was developed in China using the EpiSkin™ 3D human skin model. This EpiSkin™ Micronucleus Assay showed good predictivity and reproducibility during internal validation and is expected to contribute to in vitro genotoxicity testing as a follow-up for positive results from 2D micronucleus assay. Having developed the assay in one laboratory, further work focused on the transferability and inter-laboratory reproducibility in two additional Chinese authority laboratories (Guangdong Provincial Center for Disease Control and Prevention and Zhejiang Institute for Food and Drug Control). Formal training was provided for both laboratories, which resulted in good transferability based on the results of two positive compounds, such as mitomycin C and vinblastine. Independent experiments were then performed, and inter-laboratory reproducibility was checked using 2-acetylaminofluorene, 5-fluorouracil, 2,4-dichlorophenol, and d-limonene. The dose-responses of the positive control chemical, mitomycin C, were similar to those of the developing laboratory, and all test chemicals were correctly classified by all laboratories. Overall, there was a good transferability as well as intra- and inter-laboratory reproducibility of the EpiSkin™ Micronucleus Assay. This study further confirmed the assay's robustness and provided confidence to enter following validation stages for scientific acceptance.

Efficacy and Safety of Camrelizumab in Combination with Docetaxel + S-1 Sequenced by Camrelizumab + S-1 for Stage III (PD-1+/MSI-H/EBV+/dMMR) Gastric Cancer: Study Protocol for a Single-Center, Prospective, Open-Label, Single-Arm Trial

Background

Gastric cancer occupies the fourth highest morbidity rate of cancers worldwide. A higher incidence of gastric cancer had been found in East Asia compared to the other regions. Gastrectomy with radical lymph node dissection is the cornerstone of curative treatment for Stage III gastric cancer, and postoperative systemic chemotherapy with docetaxel, S-1 improved patients’ disease-free survival rates. However, advances in immunotherapy bring innovations in the management of patients with gastric cancer. The objective of this study was to explore the efficacy and safety of camrelizumab in combination with docetaxel + S-1, sequenced by camrelizumab + S-1 in stage III gastric cancer patients who are EBV positive, with defective mismatch repair and CPS ≥5.

Methods and analysis

This prospective, open-label, single-arm trial was performed at Renji Hospital. In this study, a total of 70 adult patients aged 18–80 years with Stage III (PD-1+/MSI-H/EBV+/dMMR) gastric cancer confirmed by post-operative pathology will be enrolled after screening. Participants will receive the specific chemotherapy regimen until 1 year after the operation or until tumor recurrence or metastasis. The primary outcome is the 3-year disease-free survival rate measured by the Clopper-Pearson method and 95% confidence intervals. The secondary outcomes include overall survival, incidence and severity of adverse effects, and laboratory abnormalities. The data will be analyzed by the Kaplan-Meier method and log-rank test. The patients will be followed up every 3 months with imaging investigation until clinical remission.

Ethics and dissemination

All participants will provide informed consent. The protocol has been approved by the Shanghai Jiaotong University School of Medicine, Renji Hospital Ethics Committee (KY2019-191). The results will be disseminated through peer-reviewed manuscripts, reports and presentations.

Clinical Trial Registration

ClinicalTrials.gov, identifier: ChiCTR1900027123. Registration date November 2019; first enrolment December 2019; expected end date December 2021; trial status: Ongoing.

Brief Abstract

A clinical trial for Stage III (PD-1+/MSI-H/EBV+/dMMR) gastric cancer patients who accepted anti-PD-1 therapy combined with docetaxel + S-1 as the first-line treatment and explored improvements in three-year disease-free survival rate.

Urban natural wetland as a sink for microplastics: A case from Lalu Wetland in Tibet, China

Microplastics have been reported in a wide range of aquatic habitats. The wetlands are considered to be important roles in microplastic migration in water bodies. Nevertheless, knowledge about the occurrence and fate of microplastics in urban natural wetland is still limited for us to better understand how they become a sink of microplastics. In this study, the distribution and characteristics of microplastics in surface water, surface sediments, and sediment cores of the Lalu Wetland watershed, China's highest urban wetland, were investigated in August 2020 and January 2021. The abundances of microplastics in the surface water were 0.06-3.05 MPs/L. Microplastic abundance in the surface sediment and sediment core was 0.01-1.10 MPs/g and 0-16.23 MPs/g, respectively. The abundance of microplastics in the water was significantly lower in the wetland than that in the channel in the watershed. Comparing the wetland inlet and outlet water, the microplastic interception rates were 53% in January and 95% in August. The characteristics and seasonal variation of microplastics in the Lalu Wetland implied that urban natural wetlands were good at intercepting microplastics, and vegetation growth might play an important role on the interception of microplastics by the wetland. The increasing of microplastics from bottom to top in the sediment cores of Lalu Wetland also indicated that the ecological risks of microplastics accumulation in sediments of urban natural wetland required further attention.

Combining international survey datasets to identify indicators of stress during the COVID-19 pandemic: A machine learning approach to improve generalization

Introduction

The magnitude and exceptional opportunity to research the psychological distress of shelter in place resulted in a publication frenzy on a smorgasbord of research studies of variable scientific robustness. Confinement, fear of contagion, social isolation, financial hardship, etc. equated to stratospheric stress levels. The decline in protective factors as a function of quarantine anecdotally reflected historic rates of anxiety and depression.

Objectives

In this study, we combined 12 variegate datasets and developed an algorithm to build a model to identify key predictors of pandemic-related stress with high accuracy and generalizability.

Methods

This study reports on existing published data. We first describe the International (Adamson et al., 2020) and then the Italian dataset (Flesia et al., 2020). The time-frame (first wave of lockdown), method (survey), measurement tool (Perceived Stress Scale), and outcome measures were extremely similar to enable consolidation of datasets (see Figure1). The Flesia et al., (2020) data set was integrated into the Adamson et al., (2020) dataset as the first step towards data validation construction of the ML predictive model.

Results

We aim to demonstrate the strength of combining cross-cultural datasets, and the applicability of ML algorithms to facilitate the process and generate a predictive model that identifies and validates key predictors of pandemic-related stress and accommodates for interaction with demographic, cultural, and other mitigating factors while concurrently having high generalizability.

Conclusions

We believe our model provides clinicians, researchers, and decision-makers with evidence to investigate the moderators and mediators of stress, and introduce novel interventions to mitigate the long-term effects of the COVID-19 pandemic.

Disclosure

No significant relationships.

The nerve-tumour regulatory axis GDNF-GFRA1 promotes tumour dormancy, imatinib resistance and local recurrence of gastrointestinal stromal tumours by achieving autophagic flux

Complete surgical resection, accessible therapeutic targets and effective tyrosine kinase inhibitors (TKIs) have not completely cured gastrointestinal stromal tumours (GISTs), with most patients suffering from residual tumours and recurrence. The existence of nerve infiltration in GIST provides a way for tumour cells to escape local resection and systemic targeted therapy, which may challenge the previous understanding of its behaviour patterns and inspire the development of more radical excision and more precise targeted therapy. Moreover, tumour dormancy has emerged as a major cause of drug resistance and tumour relapse. Among these pathways, the nerve-tumour regulatory axis GDNF-GFRA1 is activated in GISTs, assists tumour cells in achieving dormancy and protects them from apoptosis under environmental stress by enhancing autophagic flux. The concrete mechanism is that the GDNF-regulating interaction between GFRA1 and the lysosomal calcium channel MCOLN1 activates Ca²⁺-dependent TFEB signalling. Activated TFEB transcriptionally regulates intracellular lysosome levels, which could achieve feedback upregulation of cellular autophagy flux during TKI treatment. This dormancy-transition axis fills parts of the mechanistic vacancy before the onset of secondary mutations, and strategies for TKIs combined with targeting GFRA1-dependent autophagy have distinct promise as prospective clinical therapies.

Association of urinary arsenic with insulin resistance: Cross-sectional analysis of the National Health and Nutrition Examination Survey, 2015-2016

BACKGROUND

Long-term arsenic exposure is associated with diabetes in adults, the mechanism of which involves insulin resistance. The relationship between arsenic and insulin resistance in adults is unclear. We analyzed the relationship between urinary arsenic and insulin resistance in US adults.

RESULTS

We identified 815 adults aged 20-79 years who participated in the 2015-2016 National Health and Nutrition Examination Survey (NHANES). Urinary arsenic, fasting glucose, serum insulin, and other key covariates were obtained from the NHANES data. The association between urinary arsenic and insulin resistance was evaluated by analyzing the urinary arsenic level and homeostasis model assessment-insulin resistance. The median total urinary arsenic level was 6.82 µg/L. After adjusting for possible confounding factors (gender, age, and body mass index), the 80th and 20th percentile odds ratio (OR) was 1.41 (95% confidence interval [CI] 1.07, 1.87); the OR of the 70th and 30th percentiles was 1.41 (95% CI 1.08, 1.84).

CONCLUSIONS

In most subgroups, after similar adjustment, the relationship between urine total arsenic and insulin resistance remained. Total arsenic exposure in urine may be associated with insulin resistance. Evidence from larger and more adequately powered cohort studies is needed to confirm our results.

Essential role of ALKBH5-mediated RNA demethylation modification in bile acid-induced gastric intestinal metaplasia

Bile acid reflux and subsequent caudal-related homeobox 2 (CDX2) activation contribute to gastric intestinal metaplasia (IM), a precursor of gastric cancer; however, the mechanism underlying this phenomenon is unclear. Here, we demonstrate that alkylation repair homolog protein 5 (ALKBH5), a major RNA N⁶-adenosine demethylase, is required for bile acid-induced gastric IM. Mechanistically, we revealed the N⁶-methyladenosine (m⁶A) modification profile in gastric IM for the first time and identified ZNF333 as a novel m⁶A target of ALKBH5. ALKBH5 was shown to demethylate ZNF333 mRNA, leading to enhanced ZNF333 expression by abolishing m⁶A-YTHDF2-dependent mRNA degradation. In addition, ALKBH5 activated CDX2 and downstream intestinal markers by targeting the ZNF333/CYLD axis and activating NF-κB signaling. Reciprocally, p65, the key transcription factor of the canonical NF-κB pathway, enhanced the transcription activity of ALKBH5 in the nucleus, thus forming a positive feedforward circuit. Furthermore, ALKBH5 levels were positively correlated with ZNF333 and CDX2 levels in IM tissues, indicating significant clinical relevance. Collectively, our findings suggest that an m⁶A modification-associated positive feedforward loop between ALKBH5 and NF-κB signaling is involved in generating the IM phenotype of gastric epithelial cells. Targeting the ALKBH5/ZNF333/CYLD/CDX2 axis may be a useful therapeutic strategy for gastric IM in patients with bile regurgitation.

Long Non-Coding RNA NRON promotes Tumor Proliferation by regulating ALKBH5 and Nanog in Gastric Cancer

Long non-coding RNAs (lncRNAs) act as tumor suppressors or oncogenes in tumor development and progression. In this study, we explored the expression and biological role of lncRNA NRON in gastric cancer (GC). We observed that lncNRON was upregulated in GC tissues and cell lines, and high lncNRON expression was associated with malignant features and poor prognosis in GC patients. LncNRON was found to promote the proliferation and tumorigenicity of GC cells. Mechanistically, lncNRON exerted its oncogenic functions by binding to the N6-methyladenosine eraser ALKHB5 and mediating Nanog mRNA decay. In conclusion, our results suggest that lncNRON serves as an oncogenic lncRNA in GC and thus may be a promising prognostic factor and potential therapeutic target for GC patients.

Cognitive impairment, health literacy, secondary prevention capacity and behaviours in acute coronary syndrome patients at early discharge: a prospective observational study

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): the Vanguard Grant, Heart Foundation

Background

Cognitive impairment (CI) following acute coronary syndrome (ACS) is poorly understood.

Purpose

We aimed to explore the prevalence of CI in ACS patients four weeks post hospitalisation, the association with secondary prevention capacity and behaviours.

Methods

ACS inpatients who were free from visual deficits and dementia diagnoses were recruited. The post four weeks hospitalisation assessments included cognitive screening (Montreal Cognitive Assessment [MoCA], and Hopkins Verbal Learning Test [HVLT]), health literacy (Newest Vital Sign), depression (Patient Health Questionnaire-9), physical activity (Physical Activity Scale for the Elderly and Fitbit-Flex activity tracker), medication knowledge and adherence, sociodemographic and clinical factors.

Results

Participants (n = 45) had an average age of 65.07 ± 11.21 years, 82.2% were male, 64.4% were married/partnered and 82.2% had high school education or higher. CI occurred in 28.9% using either instrument, 20% using MoCA only and 15.6% using HVLT ­only. Cognitive domains affected were delayed recall (median = 5, range = 0-6) and new verbal learning and memory (15.6%). Adequate health literacy was less common in patients with CI (61.4%) than patients with normal cognition (90.3%, p = 0.024). Furthermore, patients with CI had trends for lower levels of secondary prevention capacity and behaviours, including fewer patients with high medication adherence, unlikely to be married or have an intimate partner, more depressive symptoms and lower levels of physical activity.

Conclusions

CI occurs in almost 30% of ACS patients four weeks post discharge, however a single screening tool is not sufficient to identify all cases. CI affected delayed recall, new verbal learning and memory; was associated with worse health literacy and may have potential implications for secondary prevention capacity.

Being married/having an intimate partner/being has protective effects for mild cognitive impairment in acute coronary syndrome patients

Background

Cardiovascular disease (CVD) is a leading cause of mortality and morbidity and is known to contribute to cognitive impairment, a condition common in CVD patients. Cognitive impairment (CI) is important to detect, manage and accommodate because it limits the capacity of CVD patients to learn about secondary prevention and engage in appropriate self-care including lifestyle change.

Purpose

Therefore this study aimed to determine the prevalence and predictors of cognitive impairment in acute coronary syndrome (ACS) patients during hospital admission.

Methods

ACS (myocardial infarction, unstable angina) inpatients (n=81) who did not have a neurocognitive diagnosis were recruited to a prospective descriptive study in 2019. Cognitive performance was assessed using the Montreal Cognitive Assessment (MoCA) and the Hopkins Verbal Learning Test (HVLT).

Results

The sample had an age mean of 63.49±10.86 (range 40–89) years, was mostly male (82.7%) and 50.6% were university educated. MI occurred in 56.8%, equally STEMI (28.4%) and nSTEMI (28.4%) with 70.4% treated by coronary intervention.

The mean education adjusted MOCA score was 25.73±3.05 (range 18–31) and 48.1% were classified as having mild CI (18–26). The domain with the worst performance was delayed recall/memory domain at mean 2.58±1.77 (of potential 0–5 points). The mean unadjusted recall score on HVLT was 19.56±6.18 (range 0–32), the mean z-score −0.69±1.21 (range −4.59–1.87) and 40.7% were classified as having mild CI (age and education adjusted Z-score ≥−1). Mild CI was classified by both MOCA and HVLT (both adjusted) in 24.7%.

Patients classified as having mild CI (MOCA) were significantly older (66.87 versus 60.36 years, p=0.006) and less likely and to be married or have an intimate partner (21% versus 32% p=0.039). When all factors were taken into account using multiple linear regression, higher MOCA scores in patients who were married/partnered (B=1.6) and lower scores with advancing age (B=−0.08).

Conclusions

Mild CI and decreased delayed recall is prevalent in ACS patients and patient education strategies need to be accommodate this. Being married/partnered may have protective effects, therefore additional support may need to be directed to single patients.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Heart Foundation of Australia Vanguard Award

Hypoxic gastric cancer-derived exosomes promote progression and metastasis via MiR-301a-3p/PHD3/HIF-1α positive feedback loop

Hypoxic tumor microenvironment(TME) is a universal feature in solid carcinoma and is associated with unfavorable prognosis. Tumor-derived exosomes are now significantly implicating in mediating cellular communication and interactions in TME. The aim of this study was to identify exosomal miR-301a-3p involved in gastric cancer(GC) progression and metastasis. Here, we found hypoxia promote GC exosomes release and miR-301a-3p expression in an HIF-1α-dependent manner. In hypoxic TME, enriched miR-301a-3p could be transmitted between GC cells via exosomes and then contributed to inhibit HIF-1α degradation through targeting PHD3, that were capable to hydroxylate HIF-1α subunits to ubiquitinate degradation. This synergistical positive feedback loop between HIF-1α and miR-301a-3p facilitated GC proliferation, invasion, migration, and epithelial-mesenchymal transition. In clinical samples, we further discovered circulating exosomal miR-301a-3p in serum was positively related with peritoneal metastasis. Collectively, these data indicate that GC cells could generate miR-301a-3p-rich exosomes in the hypoxic TME, which then help to HIF-1α accumulation and promote GC malignant behaviors and metastasis. Exosomal miR-301a-3p/HIF-1α signaling axis may serve as a promising predictor and potential therapeutic target of GC with metastasis.

A signature of 14 immune-related gene pairs predicts overall survival in gastric cancer

OBJECTIVE

Increasing evidence demonstrates that immune signature plays an important role in the prognosis of gastric cancer (GC). We aimed to develop and validate a robust immune-related gene pair (IRGP) signature for predicting the prognosis of GC patients.

METHODS

RNA-Seq data and corresponding clinical information of GC cohort were downloaded from the TCGA (The Cancer Genome Atlas Program) data portal. GSE84437 and GSE15459 microarray datasets were included as independent external cohorts. Least absolute shrinkage and selection operator (LASSO) regression analysis was used to build the best prognostic signature. All patients were classified into the high immune-risk and low immune-risk groups via the optimal cut-off of the signature scores determined by time-dependent receiver-operating characteristic (ROC) curve analysis. The prognostic role of the signature was measured by a log-rank test and a Cox proportional hazard regression model.

RESULTS

14 immune gene pairs consisting of 25 unique genes were identified to construct the immune prognostic signature. High immune-risk groups showed poor prognosis in the TCGA datasets and GSE84437 datasets as well as in the GSE15459 datasets (all P < 0.001). The 14-IRGP signature was an independent prognostic factor of GC after adjusting for other clinical factors (P < 0.05). Functional analysis revealed that DNA integrity checkpoint, DNA replication, T-cell receptor signaling pathway, and B-cell receptor signaling pathway were enriched in the low immune-risk groups. B cells naive and Monocytes were significantly higher in the high-risk group, and B-cell memory and T-cell CD4 memory activated were significantly higher in the low-risk group. The prognostic signature based on IRGP reflected infiltration by several types of immune cells.

CONCLUSION

The novel proposed clinical-immune signature is a promising biomarker for prediction overall survival in patients with GC and providing new insights into the treatment strategies.

Should we still use prophylactic drain in gastrectomy for cancer? A systematic review and meta-analysis

Prophylactic drain in gastrectomy for cancer is still widely used, although some evidence has disputed this practice and spreading enhanced recovery protocol has been pushing towards surgical simplification. This study aimed at assessing the impact of drain placement on important clinical outcomes, evaluating the results of randomised controlled trials (RCTs), or cohort studies whenever information provided by the former was scarce. PubMed, PMC, Cochrane Library, CNKI and Wanfang databases were searched from January 1990 to February 2019, both for RCTs and cohort studies comparing use or avoidance of prophylactic drain in gastric cancer patients undergoing gastrectomy. All RCTs and cohort studies were rated according to Jadad score and Newcastle-Ottawa-Scale, respectively. Meta-analysis was separately performed on RCTs and cohort studies. The following clinical outcomes were considered: anastomotic leak, reoperation rate, additional drain procedure, length of stay, postoperative morbidity, postoperative mortality, readmission rate and drain related complications. Overall, 3 RCTs (330 patients) and 7 cohort studies (2897 patients) were included. Seven studies came from Eastern Countries. Meta-analysis on RCTs evidenced that drain avoidance halves overall morbidity (RR = 0.47, 95%CI 0.26-0.86, p = 0.014) and slightly reduces length of stay (SMD -0.24, 95%CI -0.51-0.03, p = 0.083). Only one postoperative death occurred in the drain group. The other outcomes were either not reported or reported just by one RCT each. Meta-analysis on cohort studies, despite higher statistical power, did not highlight any significant difference. This meta-analysis showed that prophylactic drain avoidance can reduce morbidity and length of stay, while not significantly affecting other major surgical outcomes.

The Association Between Immune Characteristic and Clinical Pathology in Chinese Patients with Adenocarcinoma of Esophagogastric Junction

Purpose

Adenocarcinoma of the esophagogastric junction (AEG) patient immune characteristics were analyzed in this study, and these features were compared with patient clinical pathology and prognosis.

Patients and Methods

The clinicopathological data and prognostic information of 96 AEG patients who were admitted to Ren Ji Hospital between December 2008 and December 2015 were collected. PD-1/PD-L1, Tim-3/Gal-9, and CD3/CD8/Foxp3 expression in these patients, as well as the correlation of the expression of these molecules with clinicopathological data and survival time, were analyzed. Comparisons of count data were performed using the chi-square test or Fisher’s exact test. The survival rate and survival curves were calculated and drawn, respectively, with the Kaplan–Meier method, and the Log rank test was used for survival analysis.

Results

The positive rate for PD-L1 and Gal-9 in these AEG patients was 30.21% and 31.25%, respectively. Tim-3 positivity had a close relationship with patient Siewert type. CD8+ T cell infiltration and patient TNM stage, as well as CD3+CD8+ T cell infiltration and patient Lauren type, had a close relationship based on analysis of the correlation between immune factor expression and clinicopathological data. The group with high CD8+ T cell infiltration had an improved survival rate, while the combined analysis of Tim-3 and Gal-9 expression showed that the double-positive group had a significantly poorer prognosis than groups with other Tim-3 and Gal-9 expression patterns. The PD-L1 expression level had a close relationship with T cell infiltration in AEG patients, especially CD3+ and CD8+ T cell infiltration.

Conclusion

Tim-3 expression was higher in patients with Siewert type I tumors than in patients with tumors of other Siewert types. Patients with high CD8+ T cell infiltration had a better prognosis than patients with low CD8+ T cell infiltration, and CD8+ T cell infiltration was closely related to AEG patient TNM stage. The Tim-3 and Gal-9 double-positive group showed poor prognosis, and immune therapy could be recommended for these AEG patients.

TIGIT and PD-1 may serve as potential prognostic biomarkers for gastric cancer

Gastric Cancer (GC) is the fifth leading cause of cancer-related death in the world, and in urgent need of specific therapeutic targets to acquire prominent effectiveness. T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif (ITIM) domain (TIGIT) and programmed cell death protein 1 (PD-1) are identified to be abnormally overexpressed in various types of cancers including GC. This study aimed to investigate whether TIGIT and PD-1 could serve as potential prognostic biomarkers for GC. Firstly, TCGA GC dataset analysis and correlation analysis were utilized to inspect the relationship between expression of TIGIT, PD-1 and CD8 + T cells in GC and adjacent normal tissues. Then, flow cytometry was used to verify the data after collecting the peripheral blood, GC and adjacent normal tissues from 150 GC patients. Lastly, quantitative RT-PCR was performed to detect the expression of CD155, CD113, CD112 and TIGIT in six human GC cell lines and 631 GC patients in KM Plotter Database to conduct prognostic analysis. As results, we found that TIGIT and PD-1 were upregulated in GC tissues with high CD8 + T cells infiltration, while correlation analysis indicated they were in high-positive correlation. In addition, the flow cytometry analysis further showed that the high-expression of TIGIT in tumor microenvironment of GC could suppress the function of infiltrative CD8 + T cells, which leads to the escape of GC cells from immune killing. Furthermore, CD155 and CD112 were found abnormally upregulated in GC tissues and cell lines and the high expression of CD155, CD112 and TIGIT demonstrated poor prognosis results. In conclusion, these results provided potential therapeutic targets and prognostic biomarkers for treatment of GC in clinic.

Somatic mutation of DNAH genes implicated higher chemotherapy response rate in gastric adenocarcinoma patients

Background

The dynein axonemal heavy chain (DNAH) family of genes encode the dynein axonemal heavy chain, which is involved in cell motility. Genomic variations of DNAH family members have been frequently reported in diverse kinds of malignant tumors. In this study, we analyzed the genomic database to evaluate the mutation status of DNAH genes in gastric adenocarcinoma and further identified the significance of mutant DNAH genes as effective molecular biomarkers for predicting chemotherapy response in gastric cancer patients.

Methods

We analyzed the clinical and genomic data of gastric cancer patients published in The Cancer Genome Atlas (TCGA) project. Data on chemotherapy response, overall survival (OS) and chemotherapy-free survival were retrieved. Then, we verified the results via targeted sequencing of gastric cancer patients with similar clinical characteristics but different chemotherapeutic outcomes.

Results

In total, 132 gastric adenocarcinoma patients undergoing chemotherapy treatment from TCGA were included in our study. Somatic mutations in all 13 members of the DNAH family of genes were associated with different chemotherapy responses. Compared with patients with wild-type DNAH genes (n = 59), a significantly higher proportion of those with mutations in DNAH genes (n = 73) (55.9% vs 80.8%) responded to chemotherapy (P = 0.002). Moreover, DNAH mutations were correlated with significantly better OS (P = 0.027), chemotherapy-free survival (P = 0.027), fluoropyrimidine-free survival (P = 0.048) and platinum-free survival (P = 0.014). DNAH mutation status was an independent risk factor for OS (P = 0.015), chemotherapy-free survival (P = 0.015) and platinum-free survival (P = 0.011). We identified somatic mutations in 27 (42.2%) of the 64 stage III gastric adenocarcinoma patients receiving fluoropyrimidine-based chemotherapy by targeted exon sequencing with strict screening conditions. In our own cohort, a significantly higher proportion of patients (n = 32) with DNAH mutations than patients with wild-type DNAH genes (n = 32) had a good prognosis (OS > 48 months) (70.4% vs 35.1%) (P = 0.005).

Conclusions

Dynein axonemal heavy chain gene mutations contribute positively to chemotherapy sensitivity in gastric cancer patients.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-1867-6) contains supplementary material, which is available to authorized users.

Long non-coding RNA DNM3OS promotes tumor progression and EMT in gastric cancer by associating with Snail

Long non-coding RNAs (lncRNAs) act as tumor suppressors or oncogenes in tumor development and progression. In the present study, we explored the expression and biological role of the lncRNA DNM3OS in gastric cancer (GC). We observed that DNM3OS was upregulated in GC tissues and cell lines, and high DNM3OS expression was correlated with malignant features and served as an indicator of a poor prognosis for GC patients. DNM3OS knockdown inhibited the proliferation of GC cells, and reduced DNM3OS suppressed tumor growth in vivo. Moreover, DNM3OS depletion inhibited the migration and invasion of GC cells through the suppression of the Snail-mediated epithelial-mesenchymal transition (EMT). In conclusion, we demonstrated that DNM3OS serves as an oncogenic lncRNA in GC, and we implicated DNM3OS as a promising prognostic factor and a potential therapeutic target for GC patients.

Association between Tim‑3 and Gal‑9 expression and gastric cancer prognosis

The T‑cell immunoglobulin and mucin domain‑containing protein 3 (Tim‑3)/galectin 9 (Gal‑9) pathway, which serves a pivotal role in immune regulation, is similar to the programmed death (PD)‑1/PD‑ligand 1 pathway. Recent evidence has suggested that Tim‑3 is differentially regulated in a variety of tumors and is a potential therapeutic target. The aim of the present study was to evaluate Tim‑3 and Gal‑9 expression and cluster of differentiation (CD)3+, CD8+ and forkhead box (FOX)p3+ T cell tumor‑infiltration in gastric cancer, as well as their impact on prognosis. Tissue samples from 587 patients with gastric cancer were used to create a tissue microarray (TMA). The immune markers Tim‑3, Gal‑9, CD3, CD8 and FOXp3 were immunostained in the TMA, and correlations with clinicopathological findings and prognosis were analyzed. Several Gene Expression Omnibus gastric cancer databases and the K‑M plotter website were used to analyze the association between the expression of Tim‑3, Gal‑9 and CD8A RNA and patient survival. The results demonstrated that Tim‑3 was mainly expressed in immune cells, with minimal expression in gastric cancer cells. Its ligand, Gal‑9, was significantly overexpressed in tumor cells. Tim‑3 and Gal‑9 expression and Foxp3+ T cell density were negatively associated with the patient overall survival (OS) rate. The density of CD8+ T cells was positively associated with the patient OS rate. Tim‑3 expression and CD8+ T cell density were revealed to be independent prognostic factors for patients with gastric cancer.

[Current status and understandings in function-preserving gastrectomy under the concept of minimally invasive surgery in China, South Korea and Japan]

In the past few years, the early detection of gastric cancer has increased in China. The surgical treatment for early gastric cancer has gradually transformed from conventional gastrectomy with D2 lymphadenectomy to function-preserving gastrectomy which maximally preserves the anatomy and physiology of stomach to maintain the quality of life of the patient. Driven by minimally invasive techniques, function-preserving gastrectomies, including pylorus-preserving gastrectomy, proximal gastrectomy, sentinel node navigation surgery, etc. have already gained great attention especially in Japan and Korea. Although there are still many unsolved problems that need to be further discussed and explored, understanding of the clinical features of early gastric cancer and definition of gastric function preservation, launching clinical trials for solving practical problems, and emphasis of individualized and precision treatment will be the best strategies to improve the efficacy of early gastric cancer.

[Development and progress of diagnosis and treatment for gastric cancer in China--what inspiration we gained from Japan and Korea]

The incidence of gastric cancer in East Asia is highest in the world. Level of screening and inspection in high risk population, diagnosis and treatment in early stage, standardized surgery, minimally invasive techniques and clinical research always reach the international lead. In the past few years, the surgeons and researchers from China have already made considerable progress by learning the experience from Japan and Korea. The early detection of gastric cancer increases annually, the minimally invasive surgeries including endoscopic or laparoscopic operations are widely used, the standard surgical procedure and lymphadenectomy are popularized, meanwhile the clinical research for gastric cancer has also started. In the future, as long as following this way, we will definitely achieve better improvement in diagnosis and treatment of gastric cancer in China.

Methylation analysis of p16, SLIT2, SCARA5, and Runx3 genes in hepatocellular carcinoma

This study is to investigate the methylation status of multiple tumor suppressor 1 (p16), secreted glycoprotein 2 (SLIT2), scavenger receptor class A, member 5 putative (SCARA5), and human runt-related transcription factor 3 (Runx3) genes in the peripheral blood of hepatocellular carcinoma (HCC).This is a case-control study. The peripheral blood samples were collected from 25 HCC patients, 25 patients with high risk of HCC (defined as "internal control group"), and 25 healthy individuals (defined as "external control group"), respectively. Then the methylation status of p16, SLIT2, SCARA5, and Runx3 genes in the blood samples were analyzed by pyrosequencing. The relationship between the methylation and the clinical features of HCC patients were evaluated.The methylation levels in the 7 CpG loci of p16 gene in HCC patients were low and without statistically significant difference (P > .05) compared to the control groups. Although the methylation levels of CpG3 and CpG4 in SLIT2 gene loci were higher than those of the control groups, there was no statistically significant difference (P > .05). However, the methylation rate of CpG2 locus in SCARA5 gene in HCC patients was significantly higher (P < .05). And the methylation rates of CpG1, CpG2, CpG3, CpG4, CpG5, and CpG8 in Runx3 gene in HCC patients were significantly different to that of control groups (P < .05). We also have analyzed the correlations between the CpG islands methylation of Runx3 or SCARA5 genes and the age, gender, hepatitis B, liver cirrhosis, alpha fetal protein, or hepatitis B surface antigen (HBsAg) of the HCC patients, which all showed no significant correlations (P > .05).The methylation status of SCARA5 and Runx3 genes are abnormal in HCC patients, which may further be used as molecular markers for early auxiliary diagnosis of liver cancer.

The surgical treatment of gastric cancer in the era of minimally invasive surgery

Minimally invasive surgery is regarded as an alternative to conventional open surgery in gastric cancer. More and more surgeons devote their efforts to reduce surgical incision and acquire better recovery. Nowadays, laparoscopic distal gastrectomy has been the standard method for early stage cancer with remarkable advantage in short-term outcomes and is widely accepted by patients. The indication of laparoscopic gastrectomy has been extended to local advanced gastric cancer. However, the oncological safety has long been debated. Therefore, large scale randomized controlled clinical trials are ongoing to confirm the feasibility and safety in more advanced gastric cancer. With the accumulation of surgical experience and development of instrument, several advanced techniques, such as function preserving surgery, total laparoscopic anastomosis, sentinel node navigation surgery, robotic assisted surgery and reduced port laparoscopic gastrectomy have also been explored and applied to gastric cancer patient. All these techniques could modify the extent of surgery, reduce the risk of perioperative complications and generate potential better results in quality of life. Although recent studies have confirmed the feasibility and safety of each procedure, more evidence is required for further popularization of the newly technique. Herein we describe the current status and evidence for surgical treatment of gastric cancer in the era of minimally invasive surgery.

[Application of laparoscopic function-preservation proximal gastrectomy in the treatment of early gastric cancer]

OBJECTIVE

To discuss the safety and feasibility in the preservation to hepatic branch of vagus nerve by the side-to-side tubular gastroesophageal anastomosis within the laparoscopic radical proximal gastrectomy for early gastric cancer(EGC).

METHODS

Retrospective analysis on the intraoperative and postoperative data of 7 EGC patients receiving laparoscopic radical proximal gastrectomy from January 2014 to January 2015 was carried out. All the patients underwent the preservation of hepatic branch of the vagus nerve by side-to-side tubular gastroesophagreal anastomosis.

RESULTS

All the 7 patients completed operations successfully without conversion to open surgery. The mean operative time was (213.1 ± 22.1) minute, the mean reconstruction time was (56.9 ± 11.6) minute, and the mean blood loss was (38.6 ± 28.1) ml. Postoperative time to flatus was (2.4 ± 0.5) day, and postoperative hospital stay was (9.3 ± 0.9) day. No operation-related complications were observed. No severe malnutrition, no recurrence or death, and no severe esophageal reflux during follow-up period were found.

CONCLUSION

The preservation of hepatic branch of the vagus nerve by side-to-side tubular gastroesophagreal anastomosis within laparoscopic radical proximal gastrectomy for ECG is safe and feasible.

[Function preserving gastrectomy]

Under the premise of radical resection in the treatment, it is of great significance to preserve partial gastric function so that the early gastric cancer (EGC) patients' postoperative quality of life (QOL) can be improved. In the patients with EGC in the upper third of the stomach, the emphasis is on the prevention of reflux esophagitis caused by bile and gastric juice reflux. Pylorus-preserving gastrectomy (PPG) is applicable to the patients with EGC in the middle third of the stomach. In the patients with EGC in the lower third of the stomach, distal gastrectomy (DG) is performed in general. Various anastomosis ways are applied to reduce the negative impact of pylorus resection after DG. Furthermore, it should also be considered that reasonable vagal nerves preservation and lymph node dissection are both important for function preserving gastrectomy of EGC. Rational use of laparoscopy-assisted gastrectomy has advantages of lower invasiveness, faster recovery, etc. And the amplification effect of laparoscope can contribute to preserving nerves and gastric function.

Turning left or right? A comparative analysis in adenocarcinomas of the esophagogastric junction according to the seventh AJCC TNM classification for cancers of the esophagus and stomach: experience in a Chinese single institution

The seventh AJCC TNM classification defines rules for classifying adenocarcinomas of esophagogastric junction (AEG II and III) as a part of esophageal cancer. But there are still many controversies over the classification system. The study aims to evaluate and compare whether AEG should be classified as cancers of esophagus or stomach. A single-center cohort of patients with AEG or proximal third gastric adenocarcinoma underwent surgical resection with curative intent in Shanghai from November 2004 to July 2011. We compared the clinicopathologic features between AEG (n=291) and proximal third gastric adenocarcinoma (n=176) and analyzed overall survival probabilities of AEG using the latest seventh AJCC TNM classification for cancers. Patients with AEG not only show more advanced diseases, but also have a significantly worse 5-year survival rate than those with proximal third gastric adenocarcinoma (P=0.027). In 291 patients with AEG, the gastric T classification is monotone but indistinct except for pT2 versus pT3 (P=0.001) and pT4a versus pT4b (P=0.012). The esophageal T classification is neither monotone nor distinct. For the N classification, both schemes are monotone and distinct. The gastric scheme is indistinctive for stages IA versus IB (P=0.428), for IIA versus IIB (P=0.376), for IIB versus IIIA (P=0.086), for IIIA versus IIIB (P=0.087), and for IIIC versus IV (P=0.928). The esophageal scheme is indistinct only except for IIIB versus IIIC (P=0.002). The gastric scheme includes one heterogeneous stage group (stage IIIC, P<0.001), whereas all stage groups are homogeneous in the esophageal scheme. Although AEG shows different clinicopathological features and surgical outcomes of patients, the current seventh AJCC TNM classification which stages the AEG in the esophageal scheme does not demonstrate the advantages in the assessment of the patient prognosis. We propose a revised staging system to clarify the AEG with esophageal invasion.

Neoadjuvant concurrent chemoradiotherapy for locally advanced esophageal cancer in a single high-volume center

BACKGROUND

Neoadjuvant chemoradiotherapy (CRT) is now considered the standard of care by many centers in the treatment of both squamous cell carcinoma (SCC) and adenocarcinoma of the esophagus. This study evaluates the effectiveness of a neoadjuvant CRT protocol, as regards pathological complete response (pCR) rate and long-term survival.

METHODS

From 2003 to 2011, at Upper G.I. Surgery Division of Verona University, 155 consecutive patients with locally advanced esophageal cancers (90 SCC, 65 adenocarcinoma) were treated with a single protocol of neoadjuvant CRT (docetaxel, cisplatin, and 5-fluorouracil with 50.4 Gy of concurrent radiotherapy). Response to CRT was evaluated through percentage of pathological complete response (pCR or ypT0N0), overall (OS) and disease-related survival (DRS), and pattern of relapse.

RESULTS

One hundred thirty-one patients (84.5 %) underwent surgery. Radical resection (R0) was achieved in 123 patients (79.3 %), and pCR in 65 (41.9 %). Postoperative mortality was 0.7 % (one case). Five-year OS and DRS were respectively 43 and 49 % in the entire cohort, 52 and 59 % in R0 cases, and 72 and 81 % in pCR cases. Survival did not significantly differ between SCC and adenocarcinoma, except for pCR cases. Forty-nine patients suffered from relapse, which was mainly systemic in adenocarcinoma. Only three out of 26 pCR patients with previous adenocarcinoma developed relapse, always systemic.

CONCLUSIONS

This study suggests that patients treated with the present protocol achieve good survival and high pCR rate. Further research is necessary to evaluate whether surgery on demand is feasible in selected patients, such as pCR patients with adenocarcinoma.

Is secretoneurin a new hormone?

Numerous small potentially bioactive peptides are derived from the selective processing of the ~600 amino acid secretogranin II (SgII) precursor, but only the 31-42 amino acid segment termed secretoneurin (SN) is well-conserved from sharks to mammals. Both SNa and SNb paralogs have been identified in some teleosts, likely arising as a result of the specific genome duplication event in this lineage. Only one copy of the putative lamprey SgII (188 amino acids) could be identified which gives rise to a divergent agnathan SN that contains the signature YTPQ-X-LA-X(7)-EL sequence typical of the central core of all known SN peptides. In rodent models, SN has regulatory effects on neuroinflammation and neurotransmitter release, and possesses therapeutic potential for the induction of angiogenesis. The wide distribution of SN in neuroendocrine neurons and pituitary cells suggests important endocrine roles. The clearest example of the endocrine action of SN is the stimulatory effects on pituitary luteinizing hormone release from goldfish pituitary and mouse LβT2 gonadotroph cells, indicative of an important role in reproduction. Several lines of evidence suggest that the SN receptor is most likely a G-protein coupled protein. Microarray analysis of SN effects on dispersed goldfish pituitary cells in vitro reveals novel SN actions that include effects on genes involved in notch signaling and the guanylate cyclase pathway. Intracerebroventricular injection of SN increases feeding and locomotory behaviors in goldfish. Given that SgII appeared early in vertebrate evolution, SN is an old peptide with emerging implications as a new multifunctional hormone.

Secretoneurin stimulates the production and release of luteinizing hormone in mouse L{beta}T2 gonadotropin cells

Secretoneurin (SN) is a functional secretogranin II (SgII)-derived peptide that stimulates luteinizing hormone (LH) production and its release in the goldfish. However, the effects of SN on the pituitary of mammalian species and the underlying mechanisms remain poorly understood. To study SN in mammals, we adopted the mouse LβT2 gonadotropin cell line that has characteristics consistent with normal pituitary gonadotrophs. Using radioimmunoassay and real-time RT-PCR, we demonstrated that static treatment with SN induced a significant increment of LH release and production in LβT2 cells in vitro. We found that GnRH increased cellular SgII mRNA level and total SN-immunoreactive protein release into the culture medium. We also report that SN activated the extracellular signal-regulated kinases (ERK) in either 10-min acute stimulation or 3-h chronic treatment. The SN-induced ERK activation was significantly blocked by pharmacological inhibition of MAPK kinase (MEK) with PD-98059 and protein kinase C (PKC) with bisindolylmaleimide. SN also increased the total cyclic adenosine monophosphate (cAMP) levels similarly to GnRH. However, SN did not activate the GnRH receptor. These data indicate that SN activates the protein kinase A (PKA) and cAMP-induced ERK signaling pathways in the LH-secreting mouse LβT2 pituitary cell line.

Phytoestrogen biological actions on Mammalian reproductive system and cancer growth

Phytoestrogens are a family of diverse polyphenolic compounds derived from nature plant that structurally or functionally mimic circulating estrogen in the mammalian reproductive system. They induce estrogenic and anti-estrogenic effects in the brain-pituitary-gonad axis (a principal endocrine system involving in reproductive regulation) and peripheral reproductive organs. The dichotomy of phytoestrogen-mediated actions elucidates that they play the biological activities via complex mechanisms and belong to various chemical classes. In comparison with their unobvious physiological functions in normal reproductive tissues, there are increasing investigations showing that phytoestrogen induces significant inhibitory effects on the growth of breast and ovarian cancers through different signaling pathways. This review summarized the results of the previous studies regarding principal signaling transductions for mediating the growth of the ovarian and breast cancers. Phytoestrogen potentially modulates the signaling molecules via: (1) blocking the nuclear and membrane estrogen receptors (ER), (2) interfering with the growth factor receptor, (3) inhibiting the G protein-coupled receptor in ER-deficient cells, (4) activating apoptosis and nullifying anti-apoptotic signals.

Secretoneurin is a potential paracrine factor from lactotrophs stimulating gonadotropin release in the goldfish pituitary

Secretoneurin (SN) is a functional neuropeptide derived from the evolutionarily conserved part of precursor protein secretogranin II (SgII). In the time course study, SN (10 nM) stimulates luteinizing hormone (LH) production and secretion after 6 h of static incubation of goldfish pituitary cells. Due to the existence of SN-immunoreactivity (SN-IR) in goldfish lactotrophs, endogenous SN might exert a paracrine effect on LH in the pituitary. In an in vitro immunoneutralization experiment, coincubation with anti-SN antiserum reduces the stimulatory effect of salmon gonadotropin-releasing hormone (sGnRH) on LH release by 64%. Using Western blot analysis, we demonstrate that sGnRH significantly increases the expression of the major SgII-derived peptide (∼57 kDa, with SN-IR) and prolactin (PRL) after 12 h in the static culture of goldfish pituitary cells. Furthermore, there exists a significant correlation between the levels of these two proteins (R = 0.76, P = 0.004). Another ∼30 kDa SgII-derived peptide containing SN is only observed in sGnRH-treated pituitary cells. Consistent with the Western blot analysis results, real-time RT-PCR analysis shows that a 12-h treatment with sGnRH induced 1.6- and 1.7-fold increments in SgII and PRL mRNA levels, respectively. SgII gene expression was also associated with PRL gene expression (R = 0.66; P = 0.02). PRL cells loaded with the calcium-sensitive dye, fura 2/AM, respond to sGnRH treatment with increases in intracellular Ca(2+) concentration level, suggesting a potential mechanism of GnRH on PRL cells and thus SgII processing and SN secretion. Taken together, endogenous lactotroph-generated SN, under the control of hypothalamic GnRH, exerts a paracrine action on neighboring gonadotrophs to stimulate LH release.

Secretoneurin as a hormone regulator in the pituitary

Secretoneurin (SN) is a 33-34 amino acid peptide derived from the most conserved sequence of the secretogranin (SgII) precursor. SgII is a granin protein found in the secretory granules of neuroendocrine tissues. There are two paralogs of teleost SgII that we name here SgIIa and SgIIb. Processing of these proteins would yield SNa and SNb in fish. Secretoneurin immunoreactivity is found within all the major pituitary cell types in mammals. In goldfish, it appears to be mainly expressed in the prolactin cells of the rostral pars distalis. We have investigated the paracrine role of goldfish SN (SNa) to stimulate luteinizing hormone from gonadotrophs in the neighboring proximal pars distalis. Another source of SN is the hypophysiotropic neurons that may deliver SN to target cells by direct pituitary innervation. Little else is known about the neuroendocrine role of SN. We also discuss the evolution, distribution and production of SN in the pituitary.

New insights into granin-derived peptides: evolution and endocrine roles

The granin protein family is composed of two chromogranin and five secretogranin members that are acidic, heat-stable proteins in secretory granules in cells of the nervous and endocrine systems. We report that there is little evidence for evolutionary relationships among the granins except for the chromogranin group. The main granin members, including chromogranin A and B, and secretogranin II are moderately conserved in the vertebrates. Several small bioactive peptides can be generated by proteolysis from those homologous domains existing within the granin precursors, reflecting the conservation of biological activities in different vertebrates. In this context, we focus on reviewing the distribution and function of the major granin-derived peptides, including vasostatin, bovine CgB(1-41) and secretoneurin in vertebrate endocrine systems, especially those associated with growth, glucose metabolism and reproduction.

The secretogranin II-derived peptide secretoneurin stimulates luteinizing hormone secretion from gonadotrophs

Secretoneurin (SN) is a 33- to 34-amino acid neuropeptide derived from secretogranin-II, a member of the chromogranin family. We previously synthesized a putative goldfish (gf) SN and demonstrated its ability to stimulate LH release in vivo. However, it was not known whether goldfish actually produced the free SN peptide or whether SN directly stimulates LH release from isolated pituitary cells. Using a combination of reverse-phase HPLC and mass spectrometry analysis, we isolated for the first time a 34-amino acid free gfSN peptide from the whole brain. Moreover, Western blot analysis indicated the existence of this peptide in goldfish pituitary. Immunocytochemical localization studies revealed the presence of SN immunoreactivity in prolactin cells of rostral pars distalis of the anterior pituitary. Additionally, we found that magnocellular cells of the goldfish preoptic region are highly immunoreactive for SN. These neurons send heavily labeled projections that pass through the pituitary stalk and innervate the neurointermediate and anterior lobes. In static 12-h incubation of dispersed pituitary cells, application of SN antiserum reduced LH levels, whereas 1 and 10 nM gfSN, respectively, induced 2.5-fold (P < 0.001) and 1.9-fold (P < 0.01) increments of LH release into the medium, increases similar to those elicited by 100 nM concentrations of GnRH. Like GnRH, gfSN elevated intracellular Ca(2+) in identified gonadotrophs. Whereas we do not yet know the relative contribution of neural SN or pituitary SN to LH release, we propose that SN could act as a neuroendocrine and/or paracrine factor to regulate LH release from the anterior pituitary.