HMGB1 acts as an agent of host defense at the gut mucosal barrier

Mucosal barriers provide the first line of defense between internal body surfaces and microbial threats from the outside world. ¹ In the colon, the barrier consists of two layers of mucus and a single layer of tightly interconnected epithelial cells supported by connective tissue and immune cells. ² Microbes colonize the loose, outer layer of colonic mucus, but are essentially excluded from the tight, epithelial-associated layer by host defenses. ³ The amount and composition of the mucus is calibrated based on microbial signals and loss of even a single component of this mixture can destabilize microbial biogeography and increase the risk of disease. ^4-7 However, the specific components of mucus, their molecular microbial targets, and how they work to contain the gut microbiota are still largely unknown. Here we show that high mobility group box 1 (HMGB1), the prototypical damage-associated molecular pattern molecule (DAMP), acts as an agent of host mucosal defense in the colon. HMGB1 in colonic mucus targets an evolutionarily conserved amino acid sequence found in bacterial adhesins, including the well-characterized Enterobacteriaceae adhesin FimH. HMGB1 aggregates bacteria and blocks adhesin-carbohydrate interactions, inhibiting invasion through colonic mucus and adhesion to host cells. Exposure to HMGB1 also suppresses bacterial expression of FimH. In ulcerative colitis, HMGB1 mucosal defense is compromised, leading to tissue-adherent bacteria expressing FimH. Our results demonstrate a new, physiologic role for extracellular HMGB1 that refines its functions as a DAMP to include direct, virulence limiting effects on bacteria. The amino acid sequence targeted by HMGB1 appears to be broadly utilized by bacterial adhesins, critical for virulence, and differentially expressed by bacteria in commensal versus pathogenic states. These characteristics suggest that this amino acid sequence is a novel microbial virulence determinant and could be used to develop new approaches to diagnosis and treatment of bacterial disease that precisely identify and target virulent microbes.

Patient-reported outcome (PRO) results from the AGITG DOCTOR trial: a randomised phase 2 trial of tailored neoadjuvant therapy for resectable oesophageal adenocarcinoma

Background

AGITG DOCTOR was a randomised phase 2 trial of pre-operative cisplatin, 5 fluorouracil (CF) followed by docetaxel (D) with or without radiotherapy (RT) based on poor early response to CF, detected via PET, for resectable oesophageal adenocarcinoma. This study describes PROs over 2 years.

Methods

Participants (N = 116) completed the EORTC QLQ-C30 and oesophageal module (QLQ-OES18) before chemotherapy (baseline), before surgery, six and 12 weeks post-surgery and three-monthly until 2 years. We plotted PROs over time and calculated the percentage of participants per treatment group whose post-surgery score was within 10 points (threshold for clinically relevant change) of their baseline score, for each PRO scale. We examined the relationship between Grade 3+ adverse events (AEs) and PROs. This analysis included four groups: CF responders, non-responders randomised to DCF, non-responders randomised to DCF + RT, and “others” who were not randomised.

Results

Global QOL was clinically similar between groups from 6 weeks post-surgery. All groups had poorer functional and higher symptom scores during active treatment and shortly after surgery, particularly the DCF and DCF + RT groups. DCF + RT reported a clinically significant difference (−13points) in mean overall health/QOL between baseline and pre-surgery. Similar proportions of patients across groups scored +/− 10 points of baseline scores within 2 years for most PRO domains. Instance of grade 3+ AEs were not related to PROs at baseline or 2 years.

Conclusions

By 2 years, similar proportions of patients scored within 10 points of baseline for most PRO domains, with the exception of pain and insomnia for the DCF + RT group. Non-responders randomised to DCF or DCF + RT experienced additional short-term burden compared to CF responders, reflecting the longer duration of neoadjuvant treatment and additional toxicity. This should be weighed against clinical benefits reported in AGITG DOCTOR. This data will inform communication of the trajectory of treatment options for early CF non-responders.

Trial registration

Australia New Zealand Clinical Trials Registry (ANZCTR), ACTRN12609000665235. Registered 31 July 2009.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09270-4.

Update on optimal management for pancreatic cancer: expert perspectives from members of the Australasian Gastrointestinal Trials Group (AGITG) with invited international faculty

INTRODUCTION

Pancreatic cancer remains a challenging malignancy due to the high proportion of patients diagnosed at advanced stages and the limited treatment options. This article discusses recent evidence in the management of both localized and advanced pancreatic cancer and offers an expert opinion on current best practice.

AREAS COVERED

For patients with localized disease, the evidence for adjuvant chemotherapy is discussed as well as emerging neoadjuvant approaches for resectable, borderline resectable, and locally advanced disease. Advances in metastatic disease are discussed including cytotoxic chemotherapy, targeted therapies, and the role of genomic testing to identify patients with molecular alterations. Reviewed literature included journal publications, abstracts presented at major international oncology meetings, and ongoing clinical trials databases.

EXPERT OPINION

Pancreatic cancer is a devastating diagnosis and despite recent advances has a very poor prognosis. Only a minority of patients, 20%, are diagnosed with potentially curable disease. The shifting paradigm toward neoadjuvant therapy may improve resectability and survival rates; however, robust evidence is required. Thus far, there has only been limited progress in advanced stage disease. Genomic testing may potentially identify more treatment targets although limited to small subgroups.

P152 Poor sleep quality, individual experiences and increased risk of self-harm – A multi-method study

Introduction

The COVID-19 pandemic has caused significant psychological distress to many people across the globe. Poor sleep quality may be linked to poor mental health and increased suicide ideation. To contextualise the risk factors associated with self-harm or suicidal ideation during the COVID-19 pandemic, this cross-sectional study examined links between poor sleep quality, individual experiences and self-harm risk.

Methods

N=1544 (Mage=44.3y) from 63 countries completed an online survey in March-April 2020. Participants reported their pandemic experiences as free text responses, which were examined quantitatively for frequent word usage using Linguist Inquiry and Word Count software. Pittsburgh Sleep Quality Index assessed poor sleep quality (cut-off score >8). Item-9 of Patient Health Questionnaire-9 measured the risk of self-harm.

Results

Individuals with poor sleep quality (45%) used more negative emotional tone and had greater use of anxiety or money-related words in their comments than good sleepers (all ps<.05). Additionally, 19% of respondents (n=295) reported thoughts of self-harm at least several days a week (3.4% nearly every day). Logistic regression indicated that younger individuals, males, and those feeling isolated or less resilient had 1.2 to 1.5 times greater risk of self-harm (all ps<.001). Poor sleep quality was associated with a two-fold increased risk of self-harm (95%CI=1.5–2.7, p<.0001) after controlling for demographic variables.

Discussion

Poor sleep quality is linked to negative emotionality and increased risk of self-harm during the COVID-19 pandemic. Sleep is a modifiable factor; therefore interventions aimed at addressing sleep disturbances may improve resilience and reduce the risk of self-harm in vulnerable individuals.

Management of early-stage gastro-esophageal cancers: expert perspectives from the Australasian Gastrointestinal Trials Group (AGITG) with invited international faculty

Introduction: A multimodal approach in operable early-stage oesophago-gastric (OG) cancer has evolved in the last decade, leading to improvement in overall outcomes.Areas covered: A review of the published literature and conference abstracts was undertaken on the topic of optimal adjunctive chemotherapy or chemoradiotherapy in early-stage OG cancers. This review article focuses on the current evidence pertaining to neoadjuvant and perioperative strategies in curable OG cancers including the evolving landscape of immunotherapy and targeted drugs in this setting.Expert commentary: Adjunctive therapies in the form of preoperative chemo-radiotherapy (CRT) or chemotherapy and perioperative chemotherapy over surgery alone improve outcomes in patients with operable OG cancer. Although there are variations in practice around the world, a multi-disciplinary approach to patient care is of paramount importance. Immunotherapy and on treatment functional imaging are two examples of emerging strategies to improve the outcome for early-stage patients. A better understanding of the molecular biology of this disease may help overcome the problem of tumor heterogeneity and enable more rationally designed and targeted therapeutic interventions in the future.

Circulating tumor DNA as a potential marker of adjuvant chemotherapy benefit following surgery for localized pancreatic cancer

BACKGROUND

In early-stage pancreatic cancer, there are currently no biomarkers to guide selection of therapeutic options. This prospective biomarker trial evaluated the feasibility and potential clinical utility of circulating tumor DNA (ctDNA) analysis to inform adjuvant therapy decision making.

MATERIALS AND METHODS

Patients considered by the multidisciplinary team to have resectable pancreatic adenocarcinoma were enrolled. Pre- and post-operative samples for ctDNA analysis were collected. PCR-based-SafeSeqS assays were used to identify mutations at codon 12, 13 and 61 of KRAS in the primary pancreatic tumor and to detect ctDNA. Results of ctDNA analysis were correlated with CA19-9, recurrence-free and overall survival (OS). Patient management was per standard of care, blinded to ctDNA data.

RESULTS

Of 112 patients consented pre-operatively, 81 (72%) underwent resection. KRAS mutations were identified in 91% (38/42) of available tumor samples. Of available plasma samples (N = 42), KRAS mutated ctDNA was detected in 62% (23/37) pre-operative and 37% (13/35) post-operative cases. At a median follow-up of 38.4 months, ctDNA detection in the pre-operative setting was associated with inferior recurrence-free survival (RFS) [hazard ratio (HR) 4.1; P = 0.002)] and OS (HR 4.1; P = 0.015). Detectable ctDNA following curative intent resection was associated with inferior RFS (HR 5.4; P < 0.0001) and OS (HR 4.0; P = 0.003). Recurrence occurred in 13/13 (100%) patients with detectable ctDNA post-operatively, including in seven that received gemcitabine-based adjuvant chemotherapy.

CONCLUSION

ctDNA studies in localized pancreatic cancer are challenging, with a substantial number of patients not able to undergo resection, not having sufficient tumor tissue for analysis or not completing per protocol sample collection. ctDNA analysis, pre- and/or post-surgery, is a promising prognostic marker. Studies of ctDNA guided therapy are justified, including of treatment intensification strategies for patients with detectable ctDNA post-operatively who appear at very high risk of recurrence despite gemcitabine-based adjuvant therapy.

Randomised positive control trial of NSAID and antimicrobial treatment for calf fever caused by pneumonia

One hundred and fifty-four preweaning calves were followed between May and October 2015. Calves were fitted with continuous monitoring temperature probes (TempVerified FeverTag), programmed so a flashing light emitting diode (LED) light was triggered following six hours of a sustained ear canal temperature of ≥39.7°C. A total of 83 calves (61.9 per cent) developed undifferentiated fever, with a presumptive diagnosis of pneumonia through exclusion of other calf diseases. Once fever was detected, calves were randomly allocated to treatment groups. Calves in group 1 (NSAID) received 2 mg/kg flunixin meglumine (Allevinix, Merial) for three consecutive days and group 2 (antimicrobial) received 6 mg/kg gamithromycin (Zactran, Merial). If fever persisted for 72 hours after the initial treatment, calves were given further treatment (group 1 received antimicrobial and group 2 received NSAID). Calves in group 1 (NSAID) were five times more likely (P=0.002) to require a second treatment (the antimicrobial) after 72 hours to resolve the fever compared with the need to give group 2 (antimicrobial) calves a second treatment (NSAID). This demonstrates the importance of ongoing monitoring and follow-up of calves with respiratory disease. However, of calves with fever in group 1 (NSAID), 25.7 per cent showed resolution following NSAID-only treatment with no detrimental effect on the development of repeated fever or daily live weight gain. This suggests that NSAID alone may be a useful first-line treatment, provided adequate attention is given to ongoing monitoring to identify those cases that require additional antimicrobial treatment.

An Australian translational study to evaluate the prognostic role of inflammatory markers in patients with metastatic ColorEctal caNcer Treated with bevacizumab (Avastin™) [ASCENT]

Background

The use of bevacizumab in combination with fluoropyrimidine-containing chemotherapy is a well-established first-line and second-line treatment for patients with metastatic colorectal cancer (mCRC). However, there remains a need for reproducible, validated, inexpensive and accessible prognostic markers to aid treatment selection. The optimal treatment duration and the role of bevacizumab in certain patient subgroups, considered at particular risk of bevacizumab-mediated toxicity, also require further investigation. The aim of the ASCENT study [an Australian translational Study to evaluate the prognostic role of inflammatory markers in patients with metastatic ColorEctal caNcer Treated with bevacizumab (Avastin™)] is to evaluate the relationship between the host inflammatory response as measured by neutrophil/lymphocyte ratio (NLR) and treatment outcomes in patients with previously untreated mCRC receiving bevacizumab-based first- and second-line treatment.

Methods/design

This open-label, prospective, single arm, phase IV, Australian multi-centre study evaluates the relationship between the host inflammatory response as measured by NLR and treatment outcomes in patients with previously untreated mCRC receiving bevacizumab-based first- and second-line treatment. 150 patients will be recruited from 16 centres around Australia. Patients will receive trial treatments in two phases: Phase A: XELOX or mFOLFOX6 plus bevacizumab administered from study start until first disease progression; and Phase B: FOLFIRI plus bevacizumab administered from first disease progression until second disease progression. The primary analysis will test the association between NLR and progression free survival using a proportional Hazards Model. Secondary analyses will investigate whether the relationship can be improved upon with other prognostic biomarkers, and further characterise the safety of bevacizumab following treatment initiation, and when continued after progression in combination with standard chemotherapy regimens (presented through summary statistics and Kaplan Meier curves).

Discussion

Quantifying the relationship between NLR and PFS will inform decision making on the extent to which this simple metric may be applied clinically.

Trial registration

ClinicalTrials.gov: NCT01588990

Phase I trial of CYT997, a novel cytotoxic and vascular-disrupting agent

Background:

CYT997 is a novel microtubule inhibitor and vascular-disrupting agent with marked preclinical anti-tumour activity.

Methods:

This phase I dose-escalation study assessed the safety, tolerability, pharmacokinetics and pharmacodynamics of CYT997 administered by continuous intravenous infusion over 24 h every 3 weeks to patients with advanced solid tumours.

Results:

Thirty-one patients received CYT997 over 12 dose levels (7–358 mg m⁻²). Doses up to 202 mg m⁻² were well tolerated. Dose-limiting toxicities were observed at 269 and 358 mg m⁻², consisting of grade 3 prolonged corrected QT interval in two patients and grade 3 hypoxia and grade 4 dyspnea in one patient. All toxicities were reversible. The pharmacokinetics of CYT997 were linear over the entire dose range. Dynamic contrast-enhanced magnetic resonance imaging scans showed significant changes in tumour K^trans values consistent with vascular disruption in 7 out of 11 evaluable patients treated at CYT997 doses of ⩾65 mg m⁻². Moreover, plasma levels of von Willebrand factor and caspase-cleaved cytokeratin-18 increased post-treatment at higher dose levels. Among 22 patients evaluable for response, 18 achieved stable disease for >2 cycles.

Conclusions:

CYT997 was well tolerated at doses that were associated with pharmacodynamic evidence of vascular disruption in tumours.

Phase I evaluation of orally-administered CYT997, a novel cytotoxic vascular-disrupting agent, in patients with advanced cancer

3568

Background: CYT997 is a novel, small-molecule vascular disrupting agent which binds tubulin and inhibits microtubule assembly. The compound demonstrates potent antitumour and vascular-disrupting activity in preclinical models. A phase I study of CYT997 given by intravenous infusion showed favourable safety and tolerability, pharmacokinetics and preliminary evidence of pharmacodynamic activity. Unlike most other VDAs, CYT997 is orally available and a phase I dose-ranging study with oral capsule dosing is underway. Methods: CYT997 was administered orally every 2 weeks to patients with advanced solid tumours. Doses were escalated using an accelerated phase I design to cohort 6 and thereafter with a standard 3+3 design. Pharmacodynamic effects on tumour vasculature were assessed with DCE-MRI scans, circulating endothelial cell (CEC) assays and von Willebrand factor (vWF) plasma levels. Results: 21 patients (M/F: 16/5; median age 63, range 48–77) have been treated on study. A total of 56 cycles of CYT997 have been administered (median 2/patient, range 1–7) over 8 dose levels (15 - 164 mg/m2). Doses up to 118 mg/m2 were well tolerated. However, dose-limiting toxicities were observed at 164 mg/m2, consisting of grade 3 hypoxia in one patient and grade 3–4 asthenia in two patients. The grade 3 hypoxia was reversible. PK profiles revealed favourable oral absorption which was generally dose-linear. DCE-MRI assessments indicating significant changes in tumour Ktrans values consistent with vascular disruption were observed in 6 of 10 currently evaluated patients. No objective tumour responses were seen; however, disease stabilisation for six weeks or greater was observed in 13 patients. vWf and CEC analysis is currently ongoing. Conclusions: Orally-administered CYT997 is well tolerated at doses associated with vascular targeting activity. Moreover, its good oral bioavailability suggests the potential for novel administration schedules, including metronomic dosing.

[Table: see text]

Phase I study of CYT997, a novel cytotoxic and vascular disrupting agent, given as a 24-hour intravenous infusion to patients with advanced solid tumours

14115

Background: CYT997 is a novel tubulin-binding small molecule which inhibits microtubule assembly and also demonstrates potent vascular-disrupting activity in preclinical tumour models. Methods: CYT997 was administered by continuous infusion over 24 hours every 3 weeks to patients with advanced cancer. Dose escalation proceeded by a standard phase I design (3 patients per dose level) for the first 18 patients; subsequently, an accelerated titration design (1 patient per dose level) was utilized. Intrapatient dose escalation was permitted. Pharmacokinetic (PK) analyses were performed in the first cycle. Tumour response was determined every second cycle using RECIST criteria. Pharmacodynamic effects on the tumour vasculature were assessed with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Results: 22 patients (M/F: 11/11; median age 57.5, range 28–75) were enrolled with tumour types including melanoma (4), renal cell (4), colorectal (2), non-small cell lung (2) and adenoid cystic (2) carcinomas, mesothelioma (2) and others (6). A total of 66 cycles of CYT997 were administered (median 2/patient, range 1–6) over 10 dose levels (7, 14, 23, 35, 49, 65, 86, 114, 152 and 202 mg/m2). No dose-limiting toxicity was observed. Because of grade-2 injection site reactions in 2 patients (one each at dose levels 3 and 4), all subsequent patients received CYT997 via a central venous access device. Other toxicities included grade-2 renal toxicity at dose- level 8 in one patient with abnormal baseline renal function and grade-1 QTc prolongation in one patient at dose-level 10. No myelosuppression, gastrointestinal toxicity or clinically-significant cardiac toxicity were observed. PK data revealed dose-related increases in Cmax and AUC values. Six patients had stable disease after 4 cycles of CYT997. Conclusions: CYT997 was well tolerated at the doses studied and accrual to the 269 mg/m2 dose level will now proceed.

No significant financial relationships to disclose.

Predicting suicidal ideation in high school students

In a sample of 77 high school students, current suicidal ideation was predicted by depression, music preferences, and reasons for living scores.

Manic-depressiveness and Jungian dimensions of personality

In a sample of 105 high school seniors, among other results, their judging-perceiving scores were associated with suicidal ideation.

Depressive and manic tendencies in high school and college students

A sample of 101 high school students obtained higher mania scores than, but did not differ in depression scores from, a sample of 504 college students.

Effects of estradiol on substrate turnover during exercise in amenorrheic females

The purpose of this investigation was to determine the effects of transdermal estradiol (E2) replacement on substrate utilization during exercise. Amenorrheic females (N = 6) performed three exercise trials following 72 h of placebo (C 72) and 72 and 144 h of medicated transdermal estradiol (E2) treatment (E2 72 and E2 144). Exercise involved 90 min of treadmill running at 65% VO2max followed by timed exercise to exhaustion at 85% VO2max. Resting blood samples were obtained for glucose, insulin, free fatty acids (FFA), and E2. Exercise blood samples were obtained for E2, lactate, epinephrine, and norepinephrine. Rates of appearance and disposal were calculated for glucose and glycerol using a primed, continuous infusion of [6,6-2H] glucose and [2H5] glycerol. Medicated transdermal placement increased E2 significantly at rest, before exercise (35.03 +/- 12.3, 69.5 +/- 20.1, and 73.1 +/- 31.6 pg.mL-1 for the C 72, E2 72, and E2 144 trials, respectively, P < 0.05). Resting FFA increased significantly following E2 treatment (0.28 +/- 0.16, 0.41 +/- 0.27, and 0.40 +/- 0.21 mmol.L-1 for the C 72, E2 72, and E2 144 trials, respectively, P < 0.05). Glucose Ra was significantly decreased during exercise as a result of E2 replacement (21.9 +/- 7.7, 18.9 +/- 6.2, and 18.9 +/- 5.6 mumol.kg-1.min-1 for the C 72, E2 72, and E2 144 trials, respectively, P < 0.05). Average glucose Rd also decreased during exercise as a result of E2 replacement (21.3 +/- 7.8, 18.5 +/- 6.4, and 18.6 +/- 5.8 mumol.kg-1.min-1 for the C 72, E2 72, and E2 144 trials, respectively, P < 0.05). However, the estimated relative contribution of plasma glucose and muscle glycogen to total carbohydrate oxidation was similar among the trials. Epinephrine values were significantly lower late in exercise during the E2 72 and E2 144 trials, compared with the C 72 trial (P < 0.05). These results indicate that elevated E2 levels can alter glucose metabolism at rest and during moderate intensity exercise as a result of decreased gluconeogenesis, epinephrine secretion, and/or glucose transport.

Effect of atrial natriuretic hormone on hypertonic saline-induced suppression of the renin-aldosterone system

To evaluate the effect of physiologic doses of atrial natriuretic hormone (ANH) on hypertonic saline-induced renin-aldosterone system suppression, nine healthy subjects were studied three times: 1) on a low-salt (LS) diet with a 2 h placebo infusion; 2) on LS with 2 h infusion of human Ser-Tyr28 ANH (0.6 pmol/kg/min)(LS+ANH); and 3) on a high-salt (HS) diet with a 2 h placebo infusion. On each study day during the second hour of infusion, subjects also received 3% saline (0.1 mL/kg/min) infusion. Data from eight subjects were used for analysis because of a sampling error in one subject. During ANH infusion, plasma ANH levels increased about twofold and reached levels similar to ANH levels on HS. Serum sodium increased by 3-4 mEq/L, and serum osmolality increased by 7-8 mOsm/L during 3% saline infusion on all study days. ANH levels remained stable during 3% saline infusion. During the first hour of ANH infusion, plasma renin activity (PRA) decreased by about 24% and aldosterone levels by about 27%. Hypertonic saline caused further suppression of PRA and aldosterone. The extent of the suppression was similar under each condition, and the levels at the end of hypertonic saline infusion reached about 60% of the levels at the beginning of the saline infusion. We conclude that low-dose ANH infusion does not seem to have any major influence on PRA and aldosterone response to hypertonic saline.