Caspase-resistant ROCK1 expression prolongs survival of Eµ-Myc B cell lymphoma mice.

Apoptosis is characterized by membrane blebbing and apoptotic body formation. Caspase cleavage of ROCK1 generates an active fragment that promotes actin-myosin mediated contraction and membrane blebbing during apoptosis. Expression of caspase-resistant non-cleavable ROCK1 (Rock1 NC) prolonged survival of mice that rapidly develop B cell lymphomas due to Eµ-Myc transgene expression. Eµ-Myc; Rock1 NC mice had significantly fewer bone marrow cells relative to Eµ-Myc mice expressing wild-type ROCK1 (Rock1 WT), which was associated with altered cell cycle profiles. Circulating macrophage numbers were lower in Eµ-Myc; Rock1 NC mice, but there were higher levels of bone marrow macrophages, consistent with spontaneous cell death in Eµ-Myc; Rock1 NC mice bone marrows being more inflammatory. Rock1 WT recipient mice transplanted with pre-neoplastic Eµ-Myc; Rock1 NC bone marrow cells survived longer than mice transplanted with Eµ-Myc; Rock1 WT cells, indicating that the survival benefit was intrinsic to the Eµ-Myc; Rock1 NC bone marrow cells. The results suggest that the apoptotic death of Eµ-Myc; Rock1 NC cells generates a proliferation-suppressive microenvironment in bone marrows that reduces cell numbers and prolongs B cell lymphoma mouse survival.

Impact of the COVID-19 pandemic on patients with hepatocellular carcinoma in the West of Scotland: a cohort study.

OBJECTIVE: The COVID-19 pandemic had an undoubted impact on the provision of elective and emergency cancer care, including the diagnosis and management of patients with hepatocellular carcinoma (HCC). Our aim was to determine the effects of the COVID-19 pandemic on patients with HCC in the West of Scotland. DESIGN: This was a retrospective audit of a prospectively collated database of patients presented to the West of Scotland Multidisciplinary Team (MDT) between April and October 2020 (during the pandemic), comparing baseline demographics, characteristics of disease at presentation, diagnostic workup, treatment and outcomes with patients from April to October 2019 (pre pandemic). RESULTS: There was a 36.5% reduction in new cases referred to the MDT during the pandemic. Patients presented at a significantly later Barcelona Cancer Liver Clinic stage (24% stage D during the pandemic, 9.5% pre pandemic, p<0.001) and with a significantly higher Child-Pugh Score (46% Child-Pugh B/C during the pandemic vs 27% pre pandemic, p<0.001). We observed a reduction in overall survival (OS) among all patients with a median OS during the pandemic of 6 months versus 17 months pre pandemic (p=0.048). CONCLUSION: The impact of the COVID-19 pandemic is likely to have contributed to a reduction in the presentation of new cases and survival among patients with HCC in the West of Scotland. The reason for this is likely multifactorial, but disruption of standard care is likely to have played a significant role. Resources should be provided to address the backlog and ensure there are robust investigation and management pathways going forward.

Immunogenic Death of Hepatocellular Carcinoma Cells in Mice Expressing Caspase-Resistant ROCK1 Is Not Replicated by ROCK Inhibitors.

The morphological changes during apoptosis help facilitate "immunologically silent" cell death. Caspase cleavage of the ROCK1 kinase results in its activation, which drives the forceful contraction of apoptotic cells. We previously showed that when ROCK1 was mutated to render it caspase-resistant, there was greater liver damage and neutrophil recruitment after treatment with the hepatotoxin diethylnitrosamine (DEN). We now show that acute DEN-induced liver damage induced higher levels of pro-inflammatory cytokines/chemokines, indicative of immunogenic cell death (ICD), in mice expressing non-cleavable ROCK1 (ROCK1nc). Hepatocellular carcinoma (HCC) tumours in ROCK1nc mice had more neutrophils and CD8+ T cells relative to mice expressing wild-type ROCK1, indicating that spontaneous tumour cell death also was more immunogenic. Since ICD induction has been proposed to be tumour-suppressive, the effects of two distinct ROCK inhibitors on HCC tumours was examined. Both fasudil and AT13148 significantly decreased tumour numbers, areas and volumes, but neither resulted in greater numbers of neutrophils or CD8+ T cells to be recruited. In the context of acute DEN-induced liver damage, AT13148 inhibited the recruitment of dendritic, natural killer and CD8+ T cells to livers. These observations indicate that there is an important role for ROCK1 cleavage to limit immunogenic cell death, which was not replicated by systemic ROCK inhibitor administration. As a result, concomitant administration of ROCK inhibitors with cancer therapeutics would be unlikely to result in therapeutic benefit by inducing ICD to increase anti-tumour immune responses.

Defective apoptotic cell contractility provokes sterile inflammation, leading to liver damage and tumour suppression.

Apoptosis is characterized by profound morphological changes, but their physiological purpose is unknown. To characterize the role of apoptotic cell contraction, ROCK1 was rendered caspase non-cleavable (ROCK1nc) by mutating aspartate 1113, which revealed that ROCK1 cleavage was necessary for forceful contraction and membrane blebbing. When homozygous ROCK1nc mice were treated with the liver-selective apoptotic stimulus of diethylnitrosamine, ROCK1nc mice had more profound liver damage with greater neutrophil infiltration than wild-type mice. Inhibition of the damage-associated molecular pattern protein HMGB1 or signalling by its cognate receptor TLR4 lowered neutrophil infiltration and reduced liver damage. ROCK1nc mice also developed fewer diethylnitrosamine-induced hepatocellular carcinoma (HCC) tumours, while HMGB1 inhibition increased HCC tumour numbers. Thus, ROCK1 activation and consequent cell contraction are required to limit sterile inflammation and damage amplification following tissue-scale cell death. Additionally, these findings reveal a previously unappreciated role for acute sterile inflammation as an efficient tumour-suppressive mechanism.

Do gastroenterologists have medical inertia towards coeliac disease? A UK multicentre secondary care study.

OBJECTIVE: This study aimed to assess if there is secondary care medical inertia towards coeliac disease (CD). DESIGN: Group (1): Time from primary care presentation to diagnostic endoscopy was quantified in 151 adult patients with a positive endomysial antibody test and compared with 92 adult patients with histologically proven inflammatory bowel disease (IBD). Group (2): Across four hospitals, duodenal biopsy reports for suspected CD were reviewed (n=1423). Group (3): Clinical complexity was compared between known CD (n=102) and IBD (n=99) patients at their respective follow-up clinic appointments. Group (4): 50 gastroenterologists were questioned about their perspective on CD and IBD. RESULTS: Group (1): Suspected coeliac patients waited significantly longer for diagnostic endoscopy following referral (48.5 (28-89) days) than suspected patients with IBD (34.5 (18-70) days; p=0.003). Group (2): 1423 patients underwent diagnostic endoscopy for possible CD, with only 40.0% meeting guidelines to take four biopsies. Increased diagnosis of CD occurred if guidelines were followed (10.1% vs 4.6% p<0.0001). 12.4% of newly diagnosed CD patients had at least one non-diagnostic gastroscopy in the 5 years prior to diagnosis. Group (4): 32.0% of gastroenterologists failed to identify that CD has greater prevalence in adults than IBD. Moreover, 36.0% of gastroenterologists felt that doctors were not required for the management of CD. CONCLUSION: Prolonged waiting times for endoscopy and inadequacies in biopsy technique were demonstrated suggesting medical inertia towards CD. However, this has to be balanced against rationalising care accordingly. A Coeliac UK National Patient Charter may standardise care across the UK.

Discovery of Potent and Selective MRCK Inhibitors with Therapeutic Effect on Skin Cancer.

The myotonic dystrophy-related Cdc42-binding kinases MRCKα and MRCKß contribute to the regulation of actin-myosin cytoskeleton organization and dynamics, acting in concert with the Rho-associated coiled-coil kinases ROCK1 and ROCK2. The absence of highly potent and selective MRCK inhibitors has resulted in relatively little knowledge of the potential roles of these kinases in cancer. Here, we report the discovery of the azaindole compounds BDP8900 and BDP9066 as potent and selective MRCK inhibitors that reduce substrate phosphorylation, leading to morphologic changes in cancer cells along with inhibition of their motility and invasive character. In over 750 human cancer cell lines tested, BDP8900 and BDP9066 displayed consistent antiproliferative effects with greatest activity in hematologic cancer cells. Mass spectrometry identified MRCKα S1003 as an autophosphorylation site, enabling development of a phosphorylation-sensitive antibody tool to report on MRCKα status in tumor specimens. In a two-stage chemical carcinogenesis model of murine squamous cell carcinoma, topical treatments reduced MRCKα S1003 autophosphorylation and skin papilloma outgrowth. In parallel work, we validated a phospho-selective antibody with the capability to monitor drug pharmacodynamics. Taken together, our findings establish an important oncogenic role for MRCK in cancer, and they offer an initial preclinical proof of concept for MRCK inhibition as a valid therapeutic strategy.Significance: The development of selective small-molecule inhibitors of the Cdc42-binding MRCK kinases reveals their essential roles in cancer cell viability, migration, and invasive character. Cancer Res; 78(8); 2096-114. ©2018 AACR.

Role of bacterial overgrowth in the stomach as an additional risk factor for gastritis.

Gastric bacteria can either be ingested or ascend from the distal bowel; however, their survival is usually limited by gastric acidity and motility. A reduction in gastric acid can result in bacterial overgrowth in the stomach and proximal small bowel, and the number of organisms rises as the intragastric pH rises. The increased risk of noncardia gastric cancer seen in patients with hypochlorhydria may be explained by an excess of nitrites and N-nitroso compounds (NOCs). These compounds are found in the diet of populations with a high gastric cancer risk, but can also be produced by the organisms that exist in the hypochlorhydria stomach. It has long been hypothesized that nitrites and NOCs act as one of the triggers in the atrophy-metaplasia-dysplasia-carcinoma path. However, although indirect data have linked the premalignant changes of metaplasia and dysplasia to NOCs, direct measurement of gastric nitrites and NOCs has not confirmed such a link. The role of Helicobacter pylori in bacterial overgrowth is mainly as a cause of hypochlorhydria resulting from atrophic gastritis, leading to a reduction in the parietal cell mass. Acid-suppressing drugs can result in bacterial overgrowth and increased nitrites and NOCs, although there is no current evidence for an increased risk of gastric cancer in patients taking them. One explanation is that the stomach appears to be colonized by different organisms than those in patients with hypochlorhydria for other reasons. There is some evidence that bacterial overgrowth per se can cause gastric inflammation in mice; however, although in humans the degree of gastric inflammation is greater when overgrowth is more prominent this may simply reflect the greater degree of hypochlorhydria in patients with a more severe H pylori-induced inflammation.

Un enfoque racional para la selección de desinfectantes y esterilizantes / Rational focussing for the selection of desinfectants and sterilizing substances

El uso de desinfectantes químicos y esterilizantes en la práctica dental, constituyen una parte significativa del control de la infección. Sin embargo, el número creciente de tales agentes en el mercado y las aparentes quejas conflictivas de los fabricantes, crean dificultades en la selección de los productos apropiados para el uso en el consultorio dental. Este artículo brinda una selección de desinfectantes y esterilizantes