Marek Majewski

IL-22(+)CD4(+) T cells promote colorectal cancer stemness via STAT3 transcription factor activation and induction of the methyltransferase DOT1L.

Little is known about how the immune system impacts human colorectal cancer invasiveness and stemness. Here we detected interleukin-22 (IL-22) in patient colorectal cancer tissues that was produced predominantly by CD4(+) T cells. In a mouse model, migration of these cells into the colon cancer microenvironment required the chemokine receptor CCR6 and its ligand CCL20. IL-22 acted on cancer cells to promote activation of the transcription factor STAT3 and expression of the histone 3 lysine 79 (H3K79) methytransferase DOT1L. The DOT1L complex induced the core stem cell genes NANOG, SOX2, and Pou5F1, resulting in increased cancer stemness and tumorigenic potential. Furthermore, high DOT1L expression and H3K79me2 in colorectal cancer tissues was a predictor of poor patient survival. Thus, IL-22(+) cells promote colon cancer stemness via regulation of stemness genes that negatively affects patient outcome. Efforts to target this network might be a strategy in treating colorectal cancer patients.

IL33 Promotes Colon Cancer Cell Stemness via JNK Activation and Macrophage Recruitment

The expression and biological role of IL33 in colon cancer is poorly understood. In this study, we show that IL33 is expressed by vascular endothelial cells and tumor cells in the human colon cancer microenvironment. Administration of human IL33 and overexpression of murine IL33 enhanced human and murine colon cancer cell growth in vivo, respectively. IL33 stimulated cell sphere formation and prevented chemotherapy-induced tumor apoptosis. Mechanistically, IL33 activated core stem cell genes NANOG, NOTCH3, and OCT3/4 via the ST2 signaling pathway, and induced phosphorylation of c-Jun N terminal kinase (JNK) activation and enhanced binding of c-Jun to the promoters of the core stem cell genes. Moreover, IL33 recruited macrophages into the cancer microenvironment and stimulated them to produce prostaglandin E2, which supported colon cancer stemness and tumor growth. Clinically, tumor IL33 expression associated with poor survival in patients with metastatic colon cancer. Thus, IL33 dually targets tumor cells and macrophages and endows stem-like qualities to colon cancer cells to promote carcinogenesis. Collectively, our work reveals an immune-associated mechanism that extrinsically confers cancer cell stemness properties. Targeting the IL33 signaling pathway may offer an opportunity to treat patients with metastatic cancer. Cancer Res; 77(10); 2735-45. ©2017 AACR.

Stimulation of Mucin, Mucus, and Viscosity during Lubiprostone in Patients with Chronic Constipation may Potentially Lead to Increase of Lubrication

Objectives:The purpose of this clinical trial was to explore whether lubiprostone increases the rate of mucus and mucin secretion and its viscosity in chronic constipation (CC) patients. The secretion of chloride (CS) into the gastrointestinal tract lumen is pivotal in the body’s ability to process non-digestible food components. CS sets the optimal rate of hydration for non-digestible food components, their fluidity, and their adequate propulsion along the alimentary tract. Chloride is also instrumental in the secretion of alimentary tract mucus, and the formation of a gel-like, viscous mucus-buffer layer. This layer acts as the first line and vanguard of the mucosal barrier. This barrier is essential in mucosal lubrication and protection. Lubiprostone, a novel chloride channel stimulator ClC-2, is currently approved for the treatment of CC. Its impact on mucus, mucus secretion, and viscosity is not established.Methods:A double-blind, crossover trial was approved by the IRBs at the Kansas University Medical Center (Kansas City, KS) (study site) and at the Texas Tech University HSC (El Paso, TX) (analysis site). The study included 20 patients (17 females (F); mean age: 37 years) with symptoms of CC diagnosed according to the Rome III criteria. Patients were randomized to 1 week of therapy with lubiprostone or placebo followed by a 1 week washout and 1 week of the alternative therapy. Gastric juice was collected basally and during stimulation with pentagastrin (6 μg/kg body weight subcutaneously) at the end of weeks 1 and 3. Pentagastrin stimulation mimics food stimulation. The mucus content in gastric juice was assessed gravimetrically. The mucin content was measured after its purification using ultracentrifugation. The viscosity of the gastric secretion was measured using a digital viscometer.Results:In comparison with placebo, the volume of gastric secretion in patients with CC during administration of lubiprostone increased significantly by 50% (86.3 vs. 57.5 ml/h) (P<0.001) in basal conditions and increased by 25% (210.0 vs. 167.6 ml/h) (P=0.024) during stimulation with pentagastrin. The rate of gastric mucus secretion during therapy with lubiprostone was 91% higher (257.3 vs. 135 mg/h) (P=0.001) in basal conditions and 28% higher (348.1 vs. 270.8 mg/h) (NS) in stimulated conditions, although the latter was not statistically significant. The rate of gastric mucin secretion during lubiprostone therapy was 85% higher (98.4 vs. 65.5 mg/h) (P=0.011) in basal conditions and 38% (98.3 vs. 71.7 mg/h) (NS) higher in stimulated conditions. In basal conditions, the viscosity of gastric secretion during administration of lubiprostone increased by 240% at the lowest (P<0.001) and by 106% at the highest shear rate (P<0.001). In stimulated conditions, it increased by 226% (P<0.01) at the lowest shear rate and by 67% (P<0.01) at the highest shear rate.Conclusions:The significantly higher content of gastric mucus and mucin during therapy in basal conditions with lubiprostone in patients with CC suggests and supports the potentially leading role of lubiprostone and ClC-2 stimulation in their secretion. This increased stimulation results in profoundly increased viscosity, which in turn facilitates and/or accelerates the transit and evacuation of non-digestible food components. Although increases in mucus and mucin were observed in stimulated conditions, neither increase was statistically significant. Based on this experiment, we hypothesize that, in CC patients, the significantly increased rate of mucus and its major component, mucin secretion, during lubiprostone administration may partially explain its clinical effectiveness and also have additional clinically important effects. We propose that since the increased mucus production enhances the protective quality of the mucosal barrier, it also boosts its potential to withstand luminal aggressive components such as acid/pepsin duet, Helicobacter pylori and/or nonsteroidal anti-inflammatory drugs/aspirin, or a combination of all. Further trials are needed to test this hypothesis. As this was crossover clinical trial, the patients serve as their own controls. No interaction was found with body mass index (BMI) and treatment. The observed relationships of BMI and mucus and mucin secretions and gastric juice volume are important considerations in the design of future trials, particularly if a crossover design is not used.

Benign and precursor lesions in the esophagus.

The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on the role of salivary stimulation and esophageal secretion of protective factors in prevention of adenocarcinoma sequelae in gastroesophageal reflux disease; the pediatric conditions associated with esophageal cancer; the relationship of achalasia and pseudoachalasia with esophageal cancer; the potential for malignant transformation in eosinophilic esophagitis and overlap syndromes; the role of lymphocytic esophagitis as an overlapping phenotype; the role of Barretts esophagus as a premalignant condition; the indications and type of treatment of premalignant conditions of the esophagus; and the decision for use of endoscopical procedures in premalignant conditions of the esophagus.

MicroRNA-508 defines the stem-like/mesenchymal subtype in colorectal cancer

Colorectal cancer includes an invasive stem-like/mesenchymal subtype, but its genetic drivers, functional, and clinical relevance are uncharacterized. Here we report the definition of an altered miRNA signature defining this subtype that includes a major genomic loss of miR-508. Mechanistic investigations showed that this miRNA affected the expression of cadherin CDH1 and the transcription factors ZEB1, SALL4, and BMI1. Loss of miR-508 in colorectal cancer was associated with upregulation of the novel hypoxia-induced long noncoding RNA AK000053. Ectopic expression of miR-508 in colorectal cancer cells blunted epithelial-to-mesenchymal transition (EMT), stemness, migration, and invasive capacity in vitro and in vivo In clinical colorectal cancer specimens, expression of miR-508 negatively correlated with stemness and EMT-associated gene expression and positively correlated with patient survival. Overall, our results showed that miR-508 is a key functional determinant of the stem-like/mesenchymal colorectal cancer subtype and a candidate therapeutic target for its treatment.Significance: These results define a key functional determinant of a stem-like/mesenchymal subtype of colorectal cancers and a candidate therapeutic target for its treatment. Cancer Res; 78(7); 1751-65. ©2018 AACR.

Barrett's esophagus: proton pump inhibitors and chemoprevention I: Barrett's esophagus: proton pump inhibitors and chemoprevention

The following on proton pump inhibitors and chemoprevention in Barretts esophagus includes commentaries on normalization of esophageal refluxate; the effects of 5‐HT4 agonists on EGF secretion and of lubripristone on chloride channels agents; the role of Campylobacter toxin production; the deleterious effects of unconjugated bile acids; the role of baclofen in nonacid reflux; the threshold for adequate esophageal acid exposure; the effects of proton pump inhibitor (PPI) therapy on normalization of esophageal pH and on cell proliferation; the role of the phenotype of cellular proliferation on the effects of PPI therapy; and the value of Symptom Index and Symptom Association Probability in the evaluation of potential response to treatment.

Impairment of Salivary Mucin Production Resulting in Declined Salivary Viscosity During Naproxen Administration as a Potential Link to Upper Alimentary Tract Mucosal Injury

OBJECTIVES:Nonsteroidal anti-inflammatory drugs (NSAIDs) contribute to the esophageal mucosal injury through its direct topical impact on the luminal aspect of the surface epithelium. Its indirect, systemic impact, however, on salivary component of the esophageal pre-epithelial barrier remains to be explored. Therefore, salivary mucin secretion and viscosity at baseline and during naproxen-placebo, as well as naproxen-rabeprazole, administration were investigated.METHODS:Twenty-one asymptomatic volunteers were included in this double-blind, placebo-controlled, crossover designed study. Salivary samples were obtained in basal and pentagastrin-stimulated conditions (6 mg/kg s.c.) mimicking the food-stimulated conditions. Patients received 7 days of naproxen-placebo or naproxen-rabeprazole with a 2-week washout period in between. Salivary mucin content and viscosity were measured before and after treatment using periodic acid/Schiff’s methodology and Cone/Plate Digital Viscometer, respectively.RESULTS:The rate of salivary mucin secretion in basal condition declined by 32% during administration of naproxen-placebo (11.3±1.7 vs. 16.8±3.3 mg/h). Salivary mucin secretion in pentagastrin-stimulated condition declined significantly (by 34%) during the administration of naproxen-placebo (13.6±1.5 vs. 20.7±3.0 mg/h; P<0.05). Viscosity significantly decreased after naproxen-placebo administration in basal (by 60%) and stimulated conditions (by 56%) (P<0.001). Coadministration of rabeprazole at least partly restored the naproxen-induced decline of salivary mucin in basal condition (by 8%), and pentagastrin-stimulated conditions (by 30%).CONCLUSIONS:A significant decline of salivary mucin and viscosity during administration of naproxen may at least partly explain a propensity of patients on chronic therapy with NSAIDs to the development of esophageal mucosal injury and complications. In addition the trend to restorative capacity of rabeprazole on the quantitative impairment of salivary mucin during administration of naproxen may potentially translate into its tangible clinical benefit but it requires further investigation.

Peripheral blood T lymphocytes are downregulated by the PD-1/PD-L1 axis in advanced gastric cancer

Introduction Programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1) function as an immune checkpoint pathway that can be exploited by tumor cells to evade immuno-surveillance. The precise role of PD-1/PD-L1 inhibition of the immune response in GC is unknown. The study investigated PD-1 and PD-L1 expression on peripheral T-cells and its potential association with clinicopathological features in gastric cancer (GC) patients. Material and methods PD-1/PD-L1 expression on CD4(+) and CD8(+) T-cells from peripheral blood of 40 patients primarily diagnosed with advanced GC was evaluated by multicolor flow cytometry. Results The frequency of CD4(+)PD-1(+) and CD8(+)PD-1(+) cells in GC patients was higher than in the control group (p < 0.0001 and p < 0.01, respectively). Expression of PD-1 on CD8(+) cells in GC was higher than in the control group (p < 0.0001). The frequency of CD4(+)PD-L1(+) and CD8(+)PD-L1(+) cells was higher than in the control group (p < 0.0001). Expression of PD-L1 on CD4(+) and CD8(+) cells in GC was higher than in the control group (p < 0.0001). A higher frequency of CD4(+)PD-1(+) cells was found in diffuse-type compared to intestinal tumors (p < 0.029). A higher frequency of CD8(+)PD-1(+) cells was found in patients with poorly differentiated compared to well/moderately differentiated tumors (p < 0.019). Conclusions Downregulation of peripheral blood CD4(+) and CD8(+) lymphocytes can be associated with PD-1/PD-L1 expression. This can lead to attenuation of the general immune response in GC.

Surface CD200 and CD200R antigens on lymphocytes in advanced gastric cancer: a new potential target for immunotherapy

Introduction Gastric cancer (GC) is one of the leading causes of cancer death worldwide. The membrane glycoprotein CD200, widely expressed on multiple cells/tissues, uses a structurally similar receptor (CD200R), delivering immunoregulatory signals. There is evidence that CD200/CD200R signaling suppresses anti-tumor responses in different types of malignancies. Little is known about the CD200/CD200R pathway in GC. The aim of the study was to evaluate the frequencies of CD200+ and CD200R+ lymphocytes in patients with GC. Material and methods Forty patients primarily diagnosed with GC and 20 healthy volunteers (control group) were enrolled. The viable peripheral blood lymphocytes underwent labeling with fluorochrome-conjugated monoclonal antibodies and were analyzed using a flow cytometer. Results In the GC group, the percentages of T CD3+, CD3+/CD4+, and CD3+/CD8+ cells expressing CD200 antigen were higher than in the control group (p < 0.00013, p < 0.0004, and p < 0.0006, respectively). In the GC group, the frequencies of T CD3+, CD3+/CD4+ and CD3+/CD8+ cells expressing CD200R were lower than in the control group (p < 0.0009, p < 0.004, and p < 0.002, respectively). The percentage of B CD19+/CD200+ lymphocytes was higher in GC patients than in the control group (p < 0.00005). Lower frequency of B CD19+/CD200R+ cells was observed in GC patients compared to the control group (p < 0.0001). No differences in the frequencies of CD200+ and CD200R+ lymphocytes were found in relation to either UICC stage or histological grading of the tumors. Conclusions For GC pathogenesis, deregulation of the CD200/CD200R axis is important. High percentages of lymphocytes with CD200 expression may contribute to the continuous T cell activation and development of chronic inflammation and influence gastric carcinogenesis.

Limitations of Clinical Trials in Surgery

One of the key elements of improving the health care system in the world is to respect the recommendations resulting from the socalled evidence-based medicine (EBM). Improvement considering clinical decision-making in medicine, including surgery may be attained when best evidence based medicine (EBM) will be combined with the following: – clinical experience, – medical knowledge in the field of surgery supplemented by constant access to medical databases, – communication skills in order to engage the patient and his social environment, – proper assessment of the clinical situation in surgery. According to Rothenberger, such understanding of the functioning of the health care system based on the above-mentioned principles forms the basis for the application of evidence based surgery in everyday clinical practice (1). Defining the problem of surgery, followed by systematic exploration and evaluation of the level of the investigated surgical problem, possibility of applying individual medical solutions based on EBM and evidence-based surgery (EBS) in a patient and in accordance with the highest level of evidence, and finally systematic evaluation of therapeutic results are essential stages of creating surgery fulfilling the highest criteria of quality (2). This problem seems to be simple and obvious in assumption, but in practice, it is difficult to achieve by the surgeon. In comparison to other non-interventional medical specialties, surgical disciplines including surgery, create special conditions that clearly define and limit the ability to conduct and apply evidence based medicine. The above-mentioned is influenced by many objective conditions and numerous problems resulting from the specificity of being a surgeon. In order to follow progress in medicine one should read 19 articles everyday, 362 days a year. Every year one may observe the doubling of the number of medical publications (3). It is wellknown that in 40% of patients evidence based medicine is not applied. Additionally, the surgeons personality (self-confidence, impatience, need to take fast and responsible decisions) is not conducive to adopting all medical facts. What’s more, only approximately 60% of surgeons are aware of the functioning of EBM principles: the above-mentioned percentage is higher amongst surgeons practicing in university reference centers, and conducting research. Considering the aspect of age, young surgeons, resident and specialty surgeons are more willing to introduce EBM principles into surgery (3). Therefore, for the surgeon a major challenge is to find the best documented medical data associated with his clinical practice. Thus was born the need to create understandable, easyaccessible, and easy-to-analyze databases. Such databases would be, or already are, the basis for the novel pursuit of education, identifying research problems, or establishing surgical guidelines at the highest level of evidence (2). Another problem is the ability to use these databases. In Western countries the applica-