Inflammatory response in gastrointestinal cancers:Overview of six transmembrane epithelial antigens of the prostate in pathophysiology and clinical implications

Chronic inflammation is known to increase the risk of gastrointestinal cancers(GICs),the common solid tumors worldwide.Precancerous lesions,such as chronic atrophic inflammation and ulcers,are related to inflammatory responses in vivo and likely to occur in hyperplasia and tumorigenesis.Unfortunately,due to the lack of effective therapeutic targets,the prognosis of patients with GICs is still unsatisfactory.Interestingly,it is found that six transmembrane epithelial antigens of the prostate(STEAPs),a group of metal reductases,are significantly associated with the progression of malignancies,playing a crucial role in systemic metabolic homeostasis and inflammatory responses.The structure and functions of STEAPs suggest that they are closely related to intracellular oxidative stress,responding to inflammatory reactions.Under the imbalance status of abnormal oxidative stress,STEAP members are involved in cell transformation and the development of GICs by inhibiting or activating inflammatory process.This review focuses on STEAPs in GICs along with exploring their potential molecular regulatory mechanisms,with an aim to provide a theoretical basis for diagnosis and treatment strategies for patients suffering from these types of cancers.

Six transmembrane epithelial antigens of the prostate to illustrate inflammatory response in gastrointestinal cancers

Gastrointestinal cancer(GIC)is a common and widespread form of tumor,with colonoscopy and upper gastrointestinal endoscopy available to detect relevant precancerous polyps and lesions.However,many patients are already in the late stages when first diagnosed with such cancer,resulting in a poor prognosis.Thus,it is necessary to explore new methods and research directions in order to improve the treatment of GIC.Given the specific nature of the gastrointestinal tract,research should focus on the mechanisms of various inflammations and the interactions between food entering and exiting from the gastrointestinal tract and cancer cells.Interestingly,six transmembrane epithelial antigens of the prostates(STEAPs)have been found to be significantly linked to the progression of malignant tumors,associated with intracellular oxidative stress and playing a major role in inflammation with their structure and function.This paper explores the mechanism of STEAPs in the inflammatory response of GIC,providing a theoretical basis for the prevention and early intervention of GIC.The basic properties of the STEAP family as metal reductase are also explained.When it comes to intervention for GIC prevention,STEAPs can affect the activity of Fe3+,Cu2+reductase and regulate metal ion uptake in vivo,participating in inflammation-related iron and copper homeostasis.Thus,the mechanism of STEAPs on inflammation is of important value in the prevention of GIC.

Interleukin-1β:Friend or foe for gastrointestinal cancers

Gastrointestinal(GI)cancer is a malignancy arising in the digestive system and accounts for approximately a third of increasing global cancer-related mortality,especially in the colorectum,esophagus,stomach,and liver.Interleukin-1β(IL-1β)is a leukocytic pyrogen recognized as a tumor progression-related cytokine.IL-1βsecretion and maturation in inflammatory responses could be regulated by nuclear factor-kappaB-dependent expression of NLR family pyrin domain containing 3,inflammasome formation,and activation of IL-1 converting enzyme.Several studies have documented the pro-tumorigenic effects of IL-1β in tumor microenvironments,promoting proliferation and metastatic potential of cancer cells in vitro and tumorigenesis in vivo.The application of IL-1β inhibitors is also promising for targeted therapy development in some cancer types.However,as a leukocytic pro-inflammatory cytokine,IL-1β may also possess anti-tumorigenic effects and be type-specific in different cancers.This editorial discusses the up-to-date roles of IL-1β in GI cancers,including underlying mechanisms and down-stream signaling pathways.Understanding and clarifying the roles of IL-1β would significantly benefit future therapeutic targeting and help improve therapeutic outcomes in patients suffering from GI cancer.

Gastrointestinal problems in a valproic acid-induced rat model of autism: From maternal intestinal health to offspring intestinal function

BACKGROUND Autism spectrum disorder(ASD)is a developmental disorder characterized by social deficits and repetitive behavior.Gastrointestinal(GI)problems,such as constipation,diarrhea,and inflammatory bowel disease,commonly occur in patients with ASD.Previously,GI problems of ASD patients were attributed to intestinal inflammation and vertical mother-to-infant microbiome transmission.AIM To explore whether GI problems in ASD are related to maternal intestinal inflam-mation and gut microbiota abnormalities.METHODS An ASD rat model was developed using valproic acid(VPA).Enzyme-linked immunosorbent assay and fecal 16S rRNA sequencing were used to test GI changes.RESULTS VPA exposure during pregnancy led to pathological maternal intestinal changes,resulting in alterations in maternal gut microbiota.Additionally,the levels of inflammatory factors also increased.Moreover,prenatal exposure to VPA resulted in impaired duodenal motility in the offspring as well as increased levels of infla-mmatory factors.CONCLUSION GI problems in ASD may be associated with maternal intestinal inflammation and microbiota abnormality.Future research is required to find more evidence on the etiology and treatment of GI problems in ASD.

Nuclear factor kappa B role in inflammation associated gastrointestinal malignancies

Nuclear factor kappa B(NF-κB) has an established role in the regulation of innate immunity and inflammation.NF-κB is also involved in critical mechanisms connecting inflammation and cancer development.Recent investigations suggest that the NF-κB signaling cascade may be the central mediator of gastrointestinal malignancies including esophageal,gastric and colorectal cancers.This review will explore NF-κB's function in inflammation-associated gastrointestinal malignancies,highlighting its oncogenic contribution to each step of carcinogenesis.NF-κB's role in the inflammation-to-carcinoma sequence in gastrointestinal malignancies warrants stronger emphasis upon targeting this pathway in achieving greater therapeutic efficacy.

Connection between inflammation and carcinogenesis in gastrointestinal tract: Focus on TGF-β signaling

Inflammation is a primary defense process against various extracellular stimuli,such as viruses,pathogens,foods,and environmental pollutants.When cells respond to stimuli for short periods of time,it results in acute or physiological inflammation.However,if the stimulation is sustained for longer time or a pathological state occurs,it is known as chronic or pathological inflammation.Several studies have shown that tumorigenesis in the gastrointestinal (GI) tract is closely associated with chronic inflammation,for which abnormal cellular alterations that accompany chronic inflammation such as oxidative stresses,gene mutations,epigenetic changes,and inflammatory cytokines,are shared with carcinogenic processes,which forms a critical cross-link between chronic inflammation and carcinogenesis.Transforming growth factor (TGF)-β is a multi-potent cytokine that plays an important role in regulation of cell growth,apoptosis and differentiation.Most importantly,TGF-β is a strong anti-inflammatory cytokine that regulates the development of effector cells.TGF-β has a suppressive effect on carcinogenesis under normal conditions by inhibiting abnormal cell growth,but on the other hand,many GI cancers originate from uncontrolled cell growth and differentiation by genetic loss of TGF-β signaling molecules or perturbation of TGF-β adaptors.Once a tumor has developed,TGF-β exerts a promoting effect on the tumor itself and stromal cells to enhance cell growth,alter the responsiveness of tumor cells to stimulate invasion and metastasis,and inhibited immune surveillance.Therefore,novel development of therapeutic agents to inhibit TGF-β-induced progression of tumor and to retain its growth inhibitory activities,in addition to anti-inflammatory actions,could be useful in oncology.In this review,we discuss the role of TGF-β in inflammation and carcinogenesis of the GI tract related to abnormal TGF-β signaling.

CD74 in antigen presentation,inflammation,and cancers of the gastrointestinal tract

CD74 is a protein whose initial role in antigen presentation was recognized two decades ago. Recent studies have revealed that it has additional functions as a receptor for macrophage migration inhibitory factor and as a receptor for an important human pathogen, Helicobacter pylori （H pylon）. The role of CD74 as a receptor is important because after binding of migration inhibitory factor or H pylori, NF-κB and Erkl/2 activation occurs, along with the induction of proinflammatory cytokine secretion. This review provides an up-to-date account of the functions of CD74 and how it might be involved in inflammation and cancer within the gastrointestinal tract.

Role of nuclear receptor NR4A2 in gastrointestinal inflammation and cancers

NR4A2 is a transcription factor belonging to the steroid orphan nuclear receptor superfamily.It was originally considered to be essential in the generation and maintenance of dopaminergic neurons,and associated with neurological disorders such as Parkinson's disease.Recently,NR4A2 has been found to play a critical role in some inflammatory diseases and cancer.NR4A2 can be efficiently trans-activated by some proinflammatory cytokines,such as tumor necrosis factor-α,interleukin-1β,and vascular endothelial growth factor(VEGF).The nuclear factor-κB signaling pathway serves as a principal regulator of inducible NR4A expression in immune cells.NR4A2 can trans-activate Foxp3,a hallmark specifically expressed in regulatory T(Treg) cells,and plays a critical role in the differentiation,maintenance,and function of Treg cells.NR4A2 in T lymphocytes is pivotal for Treg cell induction and suppression of aberrant induction of Th1 under physiological and pathological conditions.High density of Foxp3 + Treg cells is significantly associated with gastrointestinal inflammation,tumor immune escape,and disease progression.NR4A2 is produced at high levels in CD133 + colorectal carcinoma(CRC) cells and significantly upregulated by cyclooxygenase-2-derived prostaglandin E 2 in a cyclic adenosine monophosphate(cAMP)/protein kinase A(PKA)-dependent manner in CRC cells.The cAMP/PKA signaling pathway is the common pathway of NR4A2-related inflammation and cancer.NR4A2 trans-activates osteopontin,a direct target of the Wnt/β-catenin pathway associated with CRC invasion,metastasis,and poor prognosis.Knockdown of endogenous NR4A2 expression attenuates VEGF-induced endothelial cell proliferation,migration and in vivo angiogenesis.Taken together,NR4A2 emerges as an important nuclear factor linking gastrointestinal inflammation and cancer,especially CRC,and should serve as a candidate therapeutic target for inflammation-related gastrointestinal cancer.

Heme oxygenase-1 system and gastrointestinal inflammation:A short review

Heme oxygenase-1(HO-1) system catalyzes heme to biologically active products:carbon monoxide,biliverdin/bilirubin and free iron.It is involved in maintaining cellular homeostasis and many physiological and pathophysiological processes.A growing body of evidence indicates that HO-1 activation may play an important protective role in acute and chronic inflammation of gastrointestinal tract.This review focuses on the current understanding of the physiological significance of HO-1 induction and its possible roles in the gastrointestinal inflammation studied to date.The ability to upregulate HO-1 by pharmacological means or using gene therapy may offer therapeutic strategies for gastrointestinal inflammation in the future.

Cathelicidin a potential therapeutic peptide for gastrointestinal inflammation and cancer

Cathelicidins, are host defense peptides synthesized and stored in circulating leukocytes and numerous types of epithelial tissues in particular the gastrointestinal (GI) tract and skin. They have been known for their antimicrobial activities against a variety of microbes. Recently it was discovered that they have other significant biological functions and produce appealing pharmacological actions against inflammation and cancer in the GI tract through defined mechanisms. Experimental evidence shows that these actions could be tissue and disease specific and concentration dependent. This article reviews some of the physiological functions of cathelicidins and also their therapeutic potential in the treatment of inflammation and cancer and also the delivery system for this peptide as targeted therapy for various disorders in the GI tract both in animals and humans.

Modulation of postoperative immune and inflammatory response by immune-enhancing enteral diet in gastrointestinal cancer patients

AIM: To evaluate if the administration of an enteral diet supplemented with glutamine, arginine and omega-3-fatty acids modulates inflammatory and immune responses after surgery. METHODS: A prospective randomized double-blind, clinical trial was performed. Forty-eight patients with gastrointestinal cancer were randomized into two groups, one group was given an isocaloric and isonitrogenous standard diet and the other was fed with the supplemented diet with glutamine, arginine and omega-3-fatty acids. Feedings were started within 48 hours after operation, and continued until day 8. All variables were measured before operation and on postoperative day 1 and 8. Immune responses were determined by phagocytosis ability, respiratory burst of polymorphonuclear cells, total lymphocytes lymphocyte subsets, nitric oxide, cytokines concentration, and inflammatory responses by plasma levels of C-reactive protein, prostaglandin E2 level. RESULTS: Tolerance of both formula diets was excellent.There were significant differences in the immunological and inflammatory responses between the two groups. In supplemented group, phagocytosis and respiratory burst after surgery was higher and C-reactive protein level was lower (P【0.01) than in the standard group. The supplemented group had higher levels of nitric oxide, total lymphocytes, T lymphocytes, T-helper cells, and NK cells. Postoperative levels of IL-6 and TNF-alpha were lower in the supplemented group (P 【0.05). CONCLUSION: It was clearly established in this trial that early postoperative enteral feeding is safe in patients who have undergone major operations for gastrointestinal cancer. Supplementation of enteral nutrition with glutamine, arginine, and omega-3-fatty acids positively modulated postsurgical immunosuppressive and inflammatory responses.

Prevention of malignant digestive system tumors should focus on the control of chronic inflammation

Chronic inflammation,through a variety of mechanisms,plays a key role in the occurrence and development of digestive system malignant tumors(DSMTs).In this study,we feature and provide a comprehensive understanding of DSMT prevention strategies based on preventing or controlling chronic inflammation.The development and evaluation of cancer prevention strategies is a longstanding process.Cancer prevention,especially in the early stage of life,should be emphasized throughout the whole life course.Issues such as the time interval for colon cancer screening,the development of direct-acting antiviral drugs for liver cancer,and the Helicobacter pylori vaccine all need to be explored in long-term,large-scale experiments in the future.

SARS-CoV-2 pathogenesis in the gastrointestinal tract mediated by Spike-induced intestinal inflammation

Dear Editor,The pathogenesis of COVID-19 in the gastrointestinal(GI)tract is well-documented[1].However,due to a lack of simple animal models,the pathogenic mechanisms of SARS-CoV-2 in the GI tract is not well established.Currently,common animal models for COVID-19 include mice,rats,hamsters,ferrets and non-human primates.

Helicobacter pylori and neurological diseases: Married by the laws of inflammation

The purpose of this paper is to review current infor-mation about the role of inflammation caused by He-licobacter pylori(H. pylori) infection in neurological diseases such as Parkinson's disease, Alzheimer's dis-ease, Guillain-Barré syndrome, multiple sclerosis, and other inflammatory diseases including ischemic stroke. Infection with H. pylori usually persists throughout life, resulting in a chronic inflammatory response with local secretion of numerous inflammatory mediators includ-ing chemokines [interleukin(IL)-8, macrophage che-motactic protein, growth-regulated oncogene(GRO)-α, chemokine(C-X-C motif) ligand 1] and cytokines [IL-1β, tumor necrosis factor-α, IL-6, IL-12, interferon-g], which can pass into the circulation and have a systemic effect. The persistence of detectable systemic and lo-cal concentrations of inflammatory mediators is likely to alter the outcome of neurological diseases. These proinflammatory factors can induce brain inflammation and the death of neurons and could eventually be asso-ciated to Parkinson's disease and also may be involved in the development of Alzheimer's disease. However,most neurological diseases are the result of a combina-tion of multiple factors, but the systemic inflammatory response is a common component and determinant in the onset, evolution, and outcome of diseases. How-ever, more studies are needed to allow understanding of the effects and mechanisms by which the inflamma-tory response generated by H. pylori infection affects neurological diseases.

Therapeutic potential of curcumin in gastrointestinal diseases

Curcumin,also known as diferuloylmethane,is derived from the plant Curcuma longa and is the active ingredient of the spice turmeric.The therapeutic activities of curcumin for a wide variety of diseases such as diabetes,allergies,arthritis and other chronic and inflammatory diseases have been known for a long time.More recently,curcumin's therapeutic potential for preventing and treating various cancers is being recognized.As curcumin's therapeutic promise is being explored more systematically in various diseases,it has become clear that,due to its increased bioavailability in the gastrointestinal tract,curcumin may be particularly suited to be developed to treat gastrointestinal diseases.This review summarizes some of the current literature of curcumin's anti-inflammatory,anti-oxidant and anti-cancer potential in inflammatory bowel diseases,hepaticfibrosis and gastrointestinal cancers.

Peritoneal adhesions after laparoscopic gastrointestinal surgery

Although laparoscopy has the potential to reduce peritoneal trauma and post-operative peritoneal adhesion formation, only one randomized controlled trial and a few comparative retrospective clinical studies have addressed this issue. Laparoscopy reduces de novo adhesion formation but has no efficacy in reducing adhesion reformation after adhesiolysis. Moreover, several studies have suggested that the reduction of de novo post-operative adhesions does not seem to have a significant clinical impact. Experimental data in animal models have suggested that CO2 pneumoperitoneum can cause acute peritoneal inflammation during laparoscopy depending on the insufflation pressure and the surgery duration. Broad peritoneal cavity protection by the insufflation of a low-temperature humidified gas mixture of CO2, N2O and O2 seems to represent the best approach for reducing peritoneal inflammation due to pneumoperitoneum. However, these experimental data have not had a significant impact on the modification of laparoscopic instrumentation. In contrast, surgeons should train themselves to perform laparoscopy quickly, and they should complete their learning curves before testing chemical anti-adhesive agents and anti-adhesion barriers. Chemical anti-adhesive agents have the potential to exert broad peritoneal cavity protection against adhesion formation, but when these agents are used alone, the concentrations needed to prevent adhesions are too high and could cause major post-operative side effects. Anti-adhesion barriers have been used mainly in open surgery, but some clinical data from laparoscopic surgeries are already available. Sprays, gels, and fluid barriers are easier to apply in laparoscopic surgery than solid barriers. Results have been encouraging with solid barriers, spray barriers, and gel barriers, but they have been ambiguous with fluid barriers. Moreover, when barriers have been used alone, the maximum protection against adhesion formation has been no greater than 60%. A recent small, randomized clinical trial suggested that the combination of broad peritoneal cavity protection with local application of a barrier could be almost 100% effective in preventing post-operative adhesion formation. Future studies should confirm the efficacy of this global strategy in preventing adhesion formation after laparoscopy by focusing on clinical end points, such as reduced incidences of bowel obstruction and abdominal pain and increased fertility.

Rare presentation of primary (AL) amyloidosis as gastrointestinal hemorrhage without systemic involvement

We are reporting a rare case of a patient with primary(AL) amyloidosis presenting with an acute non-varicealupper gastrointestinal hemorrhage in the absence ofother systemic involvement. The case report involves a58-year-old woman with significant cardiac history andhereditary blood disorder who came in complaining ofabdominal pain and coffee-ground emesis for two days.Computed tomography(CT) scan of the abdomen andpelvis with contrast revealed segmental wall thickeningof the proximal jejunum with hyperdense, heterog-enous luminal content. Similar findings were evident inthe left lower small bowel region, suspicious for smallbowel hematoma and the possibility of intraluminalclots. Esophagogastroduodenoscopy performed postresuscitation showed punctate, erythematous lesionsthroughout the stomach as well as regions of smallbowel mucosa that appeared scalloped, ulcerated, andhemorrhaged on contact. Despite initial treatment for immunostain-positive focal cytomegalovirus gastritis, follow-up esophagogastroduodenoscopy after two months continued to demonstrate friable and irregular duodenal mucosa hinting at a different underlying etiol-ogy. Pathology reports from analyses of biopsy samples highlighted infiltration and expansion of the lamina pro-pria and submucosa. Subsequent staining with congo red/crystal violet and appropriate subtyping established the diagnosis of AL(kappa)-type amyloidosis. The sig-nificance of this case lies in the fact that our patient did not have the typically seen diagnostic systemic involvements-namely of heart and kidneys-usually seen in primary(AL) amyloidosis patients. It was the persis-tent endoscopic findings and biopsy results which gave clues to the physicians regarding the possibility of an abnormal protein-deposition entity.

Non-invasive panel tests for gastrointestinal motility monitoring within the MARS-500 Project

AIM:To develop an integrated approach for monitoring gastrointestinal motility and inflammation state suitable for application in long-term spaceflights.METHODS:Breath tests based on the oral administration of 13 C-labeled or hydrogen-producing substrates followed by the detection of their metabolites(13 CO 2 or H 2) in breath were used to measure gastrointestinal motility parameters during the 520-d spaceflight ground simulation within the MARS-500 Project.In particular,the gastric emptying rates of solid and liquid contents were evaluated by 13 C-octanoic acid and 13 Cacetate breath tests,respectively,whereas the orocecal transit time was assessed by an inulin H 2-breath test,which was performed simultaneously with the 13 C-octanoic acid breath test.A ready-to-eat,standardized pre-packaged muffin containing 100 mg of 13 C-octanoic acid was used in the 13 C-octanoic acid breath test to avoid the extemporaneous preparation of solid meals.In addition,a cassette-type lateral flow immunoassay was employed to detect fecal calprotectin,a biomarker of intestinal inflammation.Because no items could be introduced into the simulator during the experiment,all materials and instrumentation required for test performance during the entire mission simulation had to be provided at the beginning of the experiment.RESULTS:The experiments planned during the simulation of a manned flight to Mars could be successfully performed by the crewmembers without any external assistance.No evident alterations(i.e.,increasing or decreasing trends) in the gastric emptying rates were detected using the 13 C-breath tests during the mission simulation,as the gastric emptying half-times were in the range of those reported for healthy subjects.In contrast to the 13 C-breath tests,the results of the inulin H 2-breath test were difficult to interpret because of the high variability of the H 2 concentration in the breath samples,even within the same subject.This variability suggested that the H 2-breath test was strongly affected by external factors,which may have been related to the diet of the crewmembers or to environmental conditions(e.g.,the accumulation of hydrogen in the simulator microenvironment).At least in closed microenvironments such as the MARS-500 simulator,13 C-breath tests should therefore be preferred to H 2-breath tests.Finally,the fecal calprotectin test showed significant alterations during the mission simulation:all of the crewmembers were negative for the test at the beginning of the simulation but showed various degrees of positivity in at least one of the subsequent tests,thus indicating the onset of an intestinal inflammation.CONCLUSION:Breath tests,especially those 13 Cbased,proved suitable for monitoring gastrointestinal motility in the 520-d isolation experiment withinMARS-500 project and can be applied in long-term spaceflights.

Nodular lymphoid hyperplasia: A marker of low-grade inflammation in irritable bowel syndrome?

AIM To evaluate the prevalence of nodular lymphoid hyperplasia(NLH) in adult patients undergoing colonoscopy and its association with known diseases. METHODS We selected all cases showing NLH at colonoscopy in a three-year timeframe, and stratified them into symptomatic patients with irritable bowel syndrome(IBS)-type symptoms or suspected inflammatory bowel disease(IBD), and asymptomatic individuals undergoing endoscopy for colorectal cancer screening.Data collection included medical history and final diagnosis. As controls, we considered all colonoscopies performed for the aforementioned indications during the same period.RESULTS One thousand and one hundred fifty colonoscopies were selected. NLH was rare in asymptomatic individuals(only 3%), while it was significantly more prevalent in symptomatic cases(32%). Among organic conditions associated with NLH, the most frequent was IBD, followed by infections and diverticular disease. Interestingly, 31% of IBS patients presented diffuse colonic NLH. NLH cases shared some distinctive clinical features among IBS patients: they were younger, more often female, and had a higher frequency of abdominal pain, bloating, diarrhoea, unspecific inflammation, self-reported lactose intolerance and metal contact dermatitis. CONCLUSION About 1/3 of patients with IBS-type symptoms or suspected IBD presented diffuse colonic NLH, which could be a marker of low-grade inflammation in a conspicuous subset of IBS patients.

Update on clinical and research application of fecal biomarkers for gastrointestinal diseases

Gastrointestinal(GI) diseases comprise a large spectrum of clinical conditions ranging from indigestion to inflammatory bowel diseases(IBDs) and carcinomas. Endoscopy is the usual method employed to diagnose these condition. Another noninvasive way to assess and diagnose GI conditions are fecal biomarkers. Fecal biomarkers provide information regarding a specific disease process and are perhaps more acceptable to clinicians and patients alike because of their non-invasivity compared to endoscopy. Aim of this review was to evaluate the current status of the fecal biomarkers in clinical and research for in GI diseases. Multiple types of fecal biomarkers are discussed in this review including; markers to assess IBD, which are released as a results of an inflammatory insults to intestinal epithelia such as antimicrobial peptides(lactoferrin) or inflammation related proteins(calprotectin). While markers related to function of digestion are primarily related to partially digested food or mucosal proteins such as abnormal amount of fecal fat α1-antitrypsin, elastase and secretary IgA. The upcoming fecal biomarker like M2 pyruvate kinase and neutrophil gelatinase associated lipocalin are discussed as well. Apart from above mention, the fecal biomarkers under exploration for possible clinical use in future are also discussed. These include cathelicidins, osteoprotegerin, β-glucuronidase, Eosinophil proteins, etc.