Publications by authors named "Laurence J Egan"

CMS4 colorectal cancer (CRC), based on the consensus molecular subtype (CMS), stratifies patients with the poorest disease-free survival rates. It is characterized by a strong mesenchymal stromal cell (MSC) signature, wound healing-like inflammation and therapy resistance. We utilized 2D and 3D , and models to assess the impact of inflammation and stromal cells on immunosuppression in CMS4 CRC.

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Immunosuppressive tumor microenvironments (TMEs) reduce the effectiveness of immune responses in cancer. Mesenchymal stromal cells (MSCs), precursors to cancer-associated fibroblasts (CAFs), promote tumor progression by enhancing immune cell suppression in colorectal cancer (CRC). Hyper-sialylation of glycans promotes immune evasion in cancer through binding of sialic acids to their receptors, Siglecs, expressed on immune cells, which results in inhibition of effector functions.

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Gastroesophageal reflux disease (GERD) is one the most common medical complaints in pregnant women. Some women continue to experience GERD symptoms after delivery. Effective management of GERD symptoms is important to improve productivity and quality of life.

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Delivering drugs directly to the inflamed intestinal sites to treat inflammatory bowel disease (IBD), particularly Crohn's and ulcerative colitis, is highly challenging. Recent advances in colitis therapy medications are expanding opportunities for improving local on-site drug availability by minimising the associated systemic side-effects. Drug delivery with targeted carrier systems has shown the potential to increase site-specificity, stability, and therapeutic efficacy.

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Introduction: Accelerated dose infliximab (IFX) induction is associated with reduced short-term colectomy rate in acute severe ulcerative colitis (ASUC). Data on medium/long-term outcomes of this strategy are limited.

Aims: Evaluate medium/long-term outcomes in patients receiving IFX induction for ASUC, comparing accelerated dose (AD) and standard dose (SD) induction.

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p53 is the most frequently mutated, well-studied tumor-suppressor gene, yet the molecular basis of the switch from p53-induced cell-cycle arrest to apoptosis remains poorly understood. Using a combination of transcriptomics and functional genomics, we unexpectedly identified a nodal role for the caspase-8 paralog and only human pseudo-caspase, FLIP(L), in regulating this switch. Moreover, we identify FLIP(L) as a direct p53 transcriptional target gene that is rapidly up-regulated in response to Nutlin-3A, an MDM2 inhibitor that potently activates p53.

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Pattern recognition receptors form an essential part of the host defenses against pathogens, in particular in the intestinal epithelium. However, despite their importance relatively little is understood about the regulation of their expression. Increasing evidence suggesting that epigenetic mechanisms such as DNA methylation and histone acetylation have substantial effects on gene expression and regulation.

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Stromal cells of mesenchymal origin reside below the epithelial compartment and provide structural support in the intestine. These intestinal stromal cells interact with both the epithelial cell compartments, as well as infiltrating hematopoietic immune cells. The importance of these cells in regulating immune homeostasis during inflammation is well recognized.

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Aberrant DNA methylation patterns have been reported in inflamed tissues and may play a role in disease. We studied DNA methylation and gene expression profiles of purified intestinal epithelial cells from ulcerative colitis patients, comparing inflamed and non-inflamed areas of the colon. We identified 577 differentially methylated sites (false discovery rate <0.

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Background: Infliximab (IFX), an anti-tumour necrosis factor alpha (TNFα) monoclonal antibody, provides clinical benefits in treating Crohn's disease (CD) but its mechanisms of action are not fully elucidated. This study investigated blood monocyte repertoires and the acute effects of IFX infusion on monocyte subset phenotype and function in IFX-treated patients with CD.

Methods: Monocytes and monocyte subsets were enumerated and phenotypically characterized by multicolor flow cytometry in freshly isolated blood from healthy controls (n = 21) and patients with CD treated with (IFX, n = 24) and without (non-IFX, n = 20) IFX.

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The tumour microenvironment (TME) is an important factor in determining the growth and metastasis of colorectal cancer, and can aid tumours by both establishing an immunosuppressive milieu, allowing the tumour avoid immune clearance, and by hampering the efficacy of various therapeutic regimens. The tumour microenvironment is composed of many cell types including tumour, stromal, endothelial and immune cell populations. It is widely accepted that cells present in the TME acquire distinct functional phenotypes that promote tumorigenesis.

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Region and cell-type specific differences in the molecular make up of colon epithelial cells have been reported. Those differences may underlie the region-specific characteristics of common colon epithelial diseases such as colorectal cancer and inflammatory bowel disease. DNA methylation is a cell-type specific epigenetic mark, essential for transcriptional regulation, silencing of repetitive DNA and genomic imprinting.

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Tumor necrosis factor alpha (TNF-α) has been widely accepted as a therapeutic target for inflammatory disorders including inflammatory bowel disease. Anti-TNF-α monoclonal antibodies (mAbs) including infliximab, adalimumab, golimumab, and certolizumab pegol have revolutionized therapy for these chronic inflammatory disorders. These agents are potent inhibitors of TNF-α, but significant evidence points to the fact that their actions extend beyond simple neutralization of the cytokine.

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Purpose Of Review: To discuss the recent landmark findings that have increased our understanding not only of the role of the epithelial cell cycle in the homeostasis of the small intestine, but also its relevance to inflammation and cancer.

Recent Findings: Recent data have unveiled novel information on protein interactions directly involved in the cell cycle as well as in the pathways that transduce external environmental signals to the cell cycle. A growing body of the recent evidence confirms the importance of food as well as hormonal regulation in the gut on cell cycle.

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Article Synopsis
  • The study investigates the role of TNF-α, a proinflammatory cytokine, in intestinal inflammation and its potential link to colorectal cancer using a mouse model.
  • Researchers induced inflammation and tumor growth in TNF mice and used etanercept to inhibit TNF-α in wild-type mice, measuring various inflammatory markers and tumor characteristics.
  • Findings indicate that TNF-α does not significantly affect colitis severity or tumor formation, suggesting that other cytokines might compensate for its absence in driving inflammation and cancer in this model.
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Article Synopsis
  • Advances in cancer treatment emphasize the effectiveness and safety of therapies, particularly radiation therapy, which often leads to gastrointestinal side effects.
  • These side effects can cause significant discomfort and may even reduce the overall effectiveness of the treatment.
  • Strategies to minimize gastrointestinal injury during radiation therapy include technical approaches to redirect radiation and biological methods to enhance tissue resistance, with ongoing research exploring various agents for prevention and treatment.
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Ionising radiation therapy is a common treatment modality for different types of cancer and its use is expected to increase with advances in screening and early detection of cancer. Radiation injury to the gastrointestinal tract is important factor working against better utility of this important therapeutic modality. Cancer survivors can suffer a wide variety of acute and chronic symptoms following radiotherapy, which significantly reduces their quality of life as well as adding an extra burden to the cost of health care.

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Inflammation can result from a range of sources including microbial infections, exposure to allergens and toxic chemicals, autoimmune disease and obesity. A well-balanced immune response can be anti-tumorigenic; however, a sustained or chronic inflammatory response is generally harmful as the immune response becomes distorted. A causal link between chronic inflammation and cancer is now well accepted and many chronically inflamed organs of the gastrointestinal tract show this association.

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Classically, adverse drug reactions had been considered as type A reactions which are related to the main pharmacological action of the drug and therefore are predictable. Such reactions are predictable, reversible, and usually can be managed by lowering the dose of the offending drug. However, other adverse effects of drugs can occur which are unrelated to the main pharmacological action of the drug - type B reactions.

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Article Synopsis
  • Inflammatory bowel disease (IBD) is linked to a higher risk of colorectal cancer (CRC), and this study investigates how inflammation affects CRC characteristics, treatment, and survival rates in patients with IBD compared to those without it.* -
  • Analyzing data from 22,335 CRC patients in Ireland, researchers found that those with IBD were generally younger, smoked less, and had fewer advanced-stage cancers at diagnosis, but treatment approaches were similar across both groups.* -
  • Despite differences in disease characteristics, the median survival time for CRC patients with IBD was about 3 years longer; however, when accounting for other factors, including age and smoking, IBD wasn't a significant predictor of survival, indicating similar disease progress
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There is a strong association between chronic inflammation and cancer formation. This correlation has been well observed in patients with long standing inflammatory bowel disease (IBD) who are at high risk of colorectal cancer (CRC). At present, there is a lack of good markers for predicting the progression from normal to neoplastic mucosa in patients with IBD.

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Transcription factor NF-κB is persistently activated in many chronic inflammatory diseases and cancers. The short term regulation of NF-κB is well understood, but little is known about the mechanisms of its long term activation. We studied the effect of a single application of TNF-α on NF-κB activity for up to 48 h in intestinal epithelial cells.

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Intestinal epithelial cells play critical roles in regulating mucosal immunity. Since epigenetic factors such as DNA methylation and histone modifications are implicated in aging, carcinogenesis, and immunity, we set out to assess any role for epigenetic factors in the regulation of intestinal epithelial cell immune responses. Experiments were conducted using the HCT116 cell line, and a subclone was genetically engineered to lack DNA methyltransferases (DNMT).

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