Animal models of gastrointestinal inflammation and cancer

Gastroprotective effects of extract of Jasminum grandiflorum L. flower in HCl/EtOH-induced gastric mucosal ulceration mice

Jasminum grandiflorum L. is a medicinal plant used to treat hepatitis and gastritis, but the mechanisms underlying its protective effects against gastrointestinal mucosal damage remain to be elucidated. In this study, we analyzed the effects of four different extracts and two compounds from the flower of J. grandiflorum in a mouse model of HCl/EtOH-induced gastric ulcer. The flower extracts alleviated gastric mucosal ulceration by increasing PGE2 production and the activity of antioxidant enzymes, along with the suppression of reactive oxygen species (ROS) generation, lipid peroxidation, apoptosis-related proteins, pro-inflammatory cytokines and nitric oxide (NO) production.

Inflammaging, an Imbalanced Immune Response That Needs to Be Restored for Cancer Prevention and Treatment in the Elderly

Nowadays, new advances in society and health have brought an increased life expectancy. However, at the same time, aging comes with complications that impact the development of autoimmunity, neurodegenerative diseases and cancer. These complications affect the quality of life and impact the public health system. Specifically, with aging, a low-grade chronic sterile systemic inflammation with self-reactivity in the absence of acute infection occurs termed inflammaging. Inflammaging is related to an imbalanced immune response that can be either naturally acquired with aging or accelerated due to external triggers. Different molecules, metabolites and inflammatory forms of cell death are highly involved in these processes. Importantly, adoptive cellular immunotherapy is a modality of treatment for cancer patients that administers ex vivo expanded immune cells in the patient. The manipulation of these cells confers them enhanced proinflammatory properties. A general consequence of proinflammatory events is the development of autoimmune diseases and cancer. Herein, we review subsets of immune cells with a pertinent role in inflammaging, relevant proteins involved in these inflammatory events and external triggers that enhance and accelerate these processes. Moreover, we mention relevant preclinical studies that demonstrate associations of chronic inflammation with cancer development.

Molecular targets for the management of gastrointestinal cancer using melatonin, a natural endogenous body hormone

Gastrointestinal cancer is one of the most common cancers globally. Melatonin, a natural endogenous body hormone, has been of interest for years, due to its anti-cancer characteristics, such as antiproliferative, antimetastatic, and cytotoxic as well as apoptotic induction. Through regulating several proteins such as melatonin upregulated mRNAs and proteins of downregulated Bcl-2-associated X protein (Bax), and B-cell lymphoma 2 (Bcl-2), as well as cytoplasmic protein such as calcium-binding proteins calmodulin or tubulin, and nuclear receptors, including RORα/RZR, and acts by non-receptor-regulated mechanisms, melatonin can exert anti-cancer efficacy. Moreover, melatonin modulates angiogenesis by targeting mRNA and protein expression of endothelin-converting enzyme (ECE-1) protein. In the present review, we address in vivo, in vitro and clinical reports on its anti-cancer efficacies, and the molecular mechanisms of action responsible for these effects. We advance the possibility of therapeutic melatonin administration for cancer therapy.

Non-invasive Bioluminescence Monitoring of Hepatocellular Carcinoma Therapy in an HCR Mouse Model

Animal models play crucial roles in the development of anticancer therapeutics. The ability to quickly assess the localized primary hepatocellular carcinoma (HCC) status in a non-invasive manner would significantly improve the effectiveness of anti-HCC therapeutic studies. However, to date, animal models with this advantage are extremely scarce. In this study, we developed a novel animal model for the fast assessment of drug efficacy against primary HCC in vivo. HCC was induced in immunocompetent hepatocarcinogenesis reporter (HCR) mice by diethylnitrosamine (DEN) injection and confirmed by histopathological staining. Using the bioluminescence imaging (BLI) technique, HCC progression was longitudinally visualized and monitored in a non-invasive way. Tests of two clinical drugs showed that both sorafenib and oxaliplatin significantly inhibited the BLI signal in mouse liver in a dose-dependent manner. The in vivo intensity of BLI signals was highly consistent with the final tumor burden status in mouse liver after drug treatment. The inhibitory effect of anti-HCC drugs was accurately evaluated through in vivo BLI intensity detection. Our study successfully established a bioluminescence mouse model for non-invasive real-time monitoring of HCC therapy, and this HCR mouse model would be a useful tool for potential anti-HCC drug screening and new therapeutic strategy development.

Nanoparticle binding attenuates the pathobiology of gastric cancer-associated Helicobacter pylori

Enteric bacteria may cause severe diseases, including gastric cancer-associated Helicobacter pylori. Their infection paths overlap with the oro-gastrointestinal uptake route for nanoparticles, increasingly occurring during environmental or consumer/medical exposure. By comprehensive independent analytical methods, such as live cell fluorescence, electron as well as atomic force microscopy and elemental analysis, we show that a wide array of nanoparticles (NPs) but not microparticles form complexes with H. pylori and enteric pathogens without the need for specific functionalization. The NP-assembly that occurred rapidly was not influenced by variations in physiological temperature, though affected by the NPs' physico-chemical characteristics. Improved binding was observed for small NPs with a negative surface charge, whereas binding could be reduced by surface 'stealth' modifications. Employing human gastric epithelial cells and 3D-organoid models of the stomach, we show that NP-coating did not inhibit H. pylori's cellular attachment. However, even the assembly of non-bactericidal silica NPs attenuated H. pylori infection by reducing CagA phosphorylation, cytoskeletal rearrangement, and IL-8 secretion. Here we demonstrate that NP binding to enteric bacteria may impact their pathobiology which could be further exploited to rationally modulate the (patho)biology of microbes by nanomaterials.

Effects of moderate alcohol consumption on gene expression related to colonic inflammation and antioxidant enzymes in rats

Excessive alcohol consumption is a risk factor associated with colorectal cancer; however, some studies have reported that moderate alcohol consumption may not contribute additional risk for developing colorectal cancer while others suggest that moderate alcohol consumption provides a protective effect that reduces colorectal cancer risk. The purpose of this study was to determine the effects of moderate voluntary alcohol (20% ethanol) intake on alternate days for 3 months in outbred Wistar rats on risk factors associated with colorectal cancer development. Colonic gene expression of cyclooxygenase-2, RelA, 8-oxoguanine DNA glycosylase 1, superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase M1, and aldehyde dehydrogenase 2 were determined. Blood alcohol content, liver function enzyme activities, and 8-oxo-deoxyguanosine DNA adducts were also assessed. Alcohol-treated rats were found to have significantly lower 8-oxo-deoxyguanosine levels in blood, a marker of DNA damage. Alanine aminotransferase and lactate dehydrogenase were both significantly lower in the alcohol group. Moderate alcohol significantly decreased cyclooxygenase-2 gene expression, an inflammatory marker associated with colorectal cancer risk. The alcohol group had significantly increased glutathione-S-transferase M1 expression, an antioxidant enzyme that helps detoxify carcinogens, such as acetaldehyde, and significantly increased aldehyde dehydrogenase 2 expression, which allows for greater acetaldehyde clearance. Increased expression of glutathione-S-transferase M1 and aldehyde dehydrogenase 2 likely contributed to reduce mucosal damage that is caused by acetaldehyde accumulation. These results indicate that moderate alcohol may reduce the risk for colorectal cancer development, which was evidenced by reduced inflammation activity and lower DNA damage after alcohol exposure.

Chemopreventive Strategies for Inflammation-Related Carcinogenesis: Current Status and Future Direction

A sustained and chronically-inflamed environment is characterized by the presence of heterogeneous inflammatory cellular components, including neutrophils, macrophages, lymphocytes and fibroblasts. These infiltrated cells produce growth stimulating mediators (inflammatory cytokines and growth factors), chemotactic factors (chemokines) and genotoxic substances (reactive oxygen species and nitrogen oxide) and induce DNA damage and methylation. Therefore, chronic inflammation serves as an intrinsic niche for carcinogenesis and tumor progression. In this article, we summarize the up-to-date findings regarding definitive/possible causes and mechanisms of inflammation-related carcinogenesis derived from experimental and clinical studies. We also propose 10 strategies, as well as candidate agents for the prevention of inflammation-related carcinogenesis.

Melatonin as a treatment for gastrointestinal cancer: a review

Gastrointestinal cancer is a disease that affects the population worldwide with high morbidity and mortality. Melatonin, an endogenously produced molecule, may provide a defense against a variety of cancer types. In particular, the ability of melatonin to inhibit gastrointestinal cancer is substantial. In this review, we first clarify the relationship between the disruption of the melatonin rhythm and gastrointestinal cancer (based on epidemiologic surveys and animal and human studies) and summarize the preventive effect of melatonin on carcinogenesis. Thereafter, the mechanisms through which melatonin exerts its anti-gastrointestinal cancer actions are explained, including inhibition of proliferation, invasion, metastasis, and angiogenesis, and promotion of apoptosis and cancer immunity. Moreover, we discuss the drug synergy effects and the role of melatonin receptors involved in the growth-inhibitory effects on gastrointestinal cancer. Taken together, the information compiled here serves as a comprehensive reference for the anti-gastrointestinal cancer actions of melatonin that have been identified to date and will hopefully aid in the design of further experimental and clinical studies and increase the awareness of melatonin as a therapeutic agent in cancers of the gastrointestinal tract.