Could Toll-like Receptor 2 Serve as Biomarker to Detect Advanced Gastric Cancer?

Gastric cancer is one of the five most common types of cancer worldwide. Due to the heterogeneous course and the involvement of many risk factors, its treatment and diagnosis is an important challenge for modern medicine. Recent studies have emphasized the i role of Toll-like receptors (TLRs) expressed on selected cells of the immune system in the pathogenesis of gastric cancer. The aim of this study was to determine the prevalence of TLR2 on T lymphocytes, B lymphocytes, monocytes, and dendritic cells in patients diagnosed with gastric cancer, with particular emphasis on the stage of the disease. Based on the obtained results, we have shown that patients with gastric cancer are characterized by a higher percentage of all tested populations of peripheral blood immune cells expressing TLR2 in relation to patients from the control group. Moreover, a detailed analysis of the collected results showed a significant link between TLR2 and the stage of the disease.

Loss of Optineurin Drives Cancer Immune Evasion via Palmitoylation-Dependent IFNGR1 Lysosomal Sorting and Degradation.

Mutations in IFN and MHC signaling genes endow immunotherapy resistance. Patients with colorectal cancer infrequently exhibit IFN and MHC signaling gene mutations and are generally resistant to immunotherapy. In exploring the integrity of IFN and MHC signaling in colorectal cancer, we found that optineurin was a shared node between the two pathways and predicted colorectal cancer patient outcome. Loss of optineurin occurs in early-stage human colorectal cancer. Immunologically, optineurin deficiency was shown to attenuate IFNGR1 and MHC-I expression, impair T-cell immunity, and diminish immunotherapy efficacy in murine cancer models and patients with cancer. Mechanistically, we observed that IFNGR1 was S-palmitoylated on Cys122, and AP3D1 bound with and sorted palmitoylated IFNGR1 to lysosome for degradation. Unexpectedly, optineurin interacted with AP3D1 to prevent palmitoylated IFNGR1 lysosomal sorting and degradation, thereby maintaining IFNγ and MHC-I signaling integrity. Furthermore, pharmacologically targeting IFNGR1 palmitoylation stabilized IFNGR1, augmented tumor immunity, and sensitized checkpoint therapy. Thus, loss of optineurin drives immune evasion and intrinsic immunotherapy resistance in colorectal cancer. SIGNIFICANCE: Loss of optineurin impairs the integrity of both IFNγ and MHC-I signaling pathways via palmitoylation-dependent IFNGR1 lysosomal sorting and degradation, thereby driving immune evasion and intrinsic immunotherapy resistance in colorectal cancer. Our work suggests that pharmacologically targeting IFNGR1 palmitoylation can stabilize IFNGR1, enhance T-cell immunity, and sensitize checkpoint therapy in colorectal cancer.See related commentary by Salvagno and Cubillos-Ruiz, p. 1623.This article is highlighted in the In This Issue feature, p. 1601.

Cancer SLC43A2 alters T cell methionine metabolism and histone methylation.

Abnormal epigenetic patterns correlate with effector T cell malfunction in tumours1-4, but the cause of this link is unknown. Here we show that tumour cells disrupt methionine metabolism in CD8+ T cells, thereby lowering intracellular levels of methionine and the methyl donor S-adenosylmethionine (SAM) and resulting in loss of dimethylation at lysine 79 of histone H3 (H3K79me2). Loss of H3K79me2 led to low expression of STAT5 and impaired T cell immunity. Mechanistically, tumour cells avidly consumed methionine and outcompeted T cells for methionine by expressing high levels of the methionine transporter SLC43A2. Genetic and biochemical inhibition of tumour SLC43A2 restored H3K79me2 in T cells, thereby boosting spontaneous and checkpoint-induced tumour immunity. Moreover, methionine supplementation improved the expression of H3K79me2 and STAT5 in T cells, and this was accompanied by increased T cell immunity in tumour-bearing mice and patients with colon cancer. Clinically, tumour SLC43A2 correlated negatively with T cell histone methylation and functional gene signatures. Our results identify a mechanistic connection between methionine metabolism, histone patterns, and T cell immunity in the tumour microenvironment. Thus, cancer methionine consumption is an immune evasion mechanism, and targeting cancer methionine signalling may provide an immunotherapeutic approach.

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.

Endoscopic removal of an impacted wooden toothpick in the wall of the sigmoid colon.

Most ingested foreign bodies usually pass through the gastrointestinal tract without any complications. Sharp foreign bodies such as a wooden toothpick may cause severe complications, leading to an acute abdomen. They may also cause mild, non-specific gastrointestinal symptoms without significant findings. We describe a case of a 60-year-old man initially diagnosed with a foreign body impacted into the wall of the rectosigmoid junction upon screening colonoscopy. Incidentally, ingestion of the wooden toothpick 6 months before admission and the presence of recurrent fever and lower abdominal pain were confirmed in the patient's history. Our video case study demonstrates the successful endoscopic removal of the wooden toothpick impacted into the colon wall.

The clinical importance of changes in Treg and Th17 lymphocyte subsets in splenectomized patients after spleen injury.

BACKGROUND: Splenectomized patients are more prone to bacterial infections due to their immunocompromised status. Little is known about the role of T helper 17 (Th17) and T regulatory cells (Treg) in the immune system of patients after the removal of the spleen. OBJECTIVES: The aim of the present study was to analyze possible changes in CD4+ lymphocyte T subsets, especially Treg and Th17, in patients who had undergone splenectomy. MATERIAL AND METHODS: The study included a group of 67 male patients (41.74 ±16.22 years). All patients had undergone splenectomy because of spleen injury. Mean time elapsed from splenectomy to analysis was 9.1 ±4.6 years. Control samples were obtained from 20 male healthy volunteers. The percentages and absolute counts of Th17 and Treg were measured using the flow cytometry method. RESULTS: The analysis of the antibody titer against 23 serotypes of Streptococcus pneumoniae (S. pneumoniae) in the splenectomized patients revealed its elevated values compared to controls (p = 0.0016). Higher percentages and absolute counts of Treg cells were found in the splenectomized group vs controls (p < 0.000007). Lower percentages and absolute counts of the Th17 subset were found in the study group vs controls (p < 0.000002 and p < 0.00006, respectively). The Treg cell percentage was positively correlated with the antibody titer against S. pneumoniae (p < 0.02). Th17 cells were reversely correlated with the antibody titer (p < 0.004 and p < 0.001 for absolute counts and percentage values, respectively). The Th17 subset values were significantly lower in the splenectomized patients who reported a higher frequency of upper respiratory tract infections (URTI) (p < 0.0001). No correlations were found between the time elapsed since splenectomy and the Treg or Th17 cell values in the study group. CONCLUSIONS: Splenectomy results in an important deterioration of the Treg/Th17 cell balance with a predominance of immunoregulatory Tregs, which can contribute to insufficient immune response to infection.

miR-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.

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.

Inflammatory regulatory T cells in the microenvironments of ulcerative colitis and colon carcinoma.

Foxp3(+)CD4(+) regulatory T (Treg) cells are thought to express negligible levels of effector cytokines, and inhibit immune responses and inflammation. Here, we have identified a population of IL-8(+)Foxp3(+)CD4(+) T cells in human peripheral blood, which is selectively increased in the microenvironments of ulcerative colitis and colon carcinoma. Phenotypically, this population is minimally overlapping with IL-17(+)Foxp3(+)CD4(+) T cells, and is different from IL-8(-)Foxp3(+)CD4(+) T cells in the same microenvironment. 40-60% of IL-8(+)Foxp3(+)CD4(+) T cells exhibit naive phenotype and express CD127, whereas IL-8(-)Foxp3(+)CD4(+) cells are basically memory T cells and express minimal CD127. The levels of CXCR5 expression are higher in IL-8(+)Foxp3(+) cells than in IL-8(-)Foxp3(+) cells. IL-2 and TGFß induce IL-8(+)Foxp3(+) T cells. Exogenous Foxp3 expression promotes IL-8(+)Foxp3(+) T cells and inhibits effector cytokine IFNγ and IL-2 expression. Furthermore, Foxp3 binds to IL-8 proximal promoter and increases its activity. Functionally, IL-8(+)Foxp3(+) T cells inhibit T cell proliferation and effector cytokine production, but stimulate inflammatory cytokine production in the colon tissues, and promote neutrophil trafficking through IL-8. Thus, IL-8(+)Foxp3(+) cells may be an "inflammatory" Treg subset, and possess inflammatory and immunosuppressive dual biological activities. Given their dual roles and localization, these cells may be in a unique position to support tumor initiation and development in human chronic inflammatory environment.

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.

Minimally invasive surgery for esophageal cancer - benefits and controversies.

Open esophagectomy (OE) requires extensive surgery and is associated with significant morbidity and mortality. Furthermore, the long-term results of esophageal cancer surgery are not satisfactory; hence, the best surgical approach is constantly under debate. During the last twenty years, minimally invasive esophagectomy (MIE) employing laparoscopy and/or thoracoscopy has been introduced in a growing number of centers worldwide. To date, several studies have demonstrated that MIE has better outcomes than OE, as it results in shorter hospital stay and decreased overall morbidity. However, the length of operating time in MIE is increased in comparison to OE. The survival benefit has been demonstrated to be similar in OE and MIE. Highly advanced laparo-thoracoscopic skills are required to perform MIE; along with the relatively long learning curve, this makes MIE feasible only in high-volume, experienced university surgical centers. There is a need for further large-scale comparative studies to prove the superiority of MIE over open surgery.

Understanding clinical issues in postoperative nutrition after pancreaticoduodenectomy.

Postoperative nutrition support for patients undergoing pancreaticoduodenectomy (Whipple's procedure) may be complicated due to gastrointestinal tract dysfunction (gastroparesis, dumping, and malabsorption) subsequent to the procedure. Clinical management of these patients may be adversely affected by procedure-specific knowledge deficits (method of gastrointestinal [GI] reconstruction), common and expected surgical complications, and the available route for alimentation. It is the aim of this report to provide the reader with an overview of the procedure, common postoperative nutrition issues, and available interventions.

Radiofrequency ablation for incidentally identified primary intrahepatic cholangiocarcinoma.

Cholangiocarcinoma is the second most common primary hepato-biliary malignancy. The majority of patients with primary hepatic tumors are not suitable candidates for resection, due to advanced stage of the disease at presentation, anatomic limitations and medical co-morbidities. At present, radiofrequency ablation (RFA) may offer an alternative, feasible and safe therapy for selected patients with hepatic tumors, who are not otherwise candidates for hepatic resection. Herein, we present the case of successful RFA in a patient with a solitary, primary intrahepatic cholangiocarcinoma. The patient remained free of disease 24 mo after the procedure, and is still followed up. This is the first report of RFA application in the treatment of primary intrahepatic cholangiocarcinoma.

Unusual clinical course of metachronous melanomas of the upper digestive system.

Melanoma of the gastrointestinal tract is a rare, highly malignant neoplasm of poor prognosis. This is description of an unusual case of surgically treated patient with two metachronous malignant melanomas of the stomach and the esophagus. The former lesion was located in the cardia and effectively treated with R0 total gastrectomy. The latter was recognized after 67 mo and appeared as irregular, flat, pigmented areas located in the mid esophagus. Subtotal esophagectomy via right-sided thoracotomy, laparotomy and left-sided cervicotomy was performed, but neoplastic cells were found in distal margin (R1). Fourteen months after esophagectomy multiple lung metastases were detected. Patient died 2 mo later.

Recurrent inflammatory fibroid polyp of cardia: a case report.

Inflammatory fibroid polyp is one of the chronic inflammatory diseases in the digestive tract, which often mimics the submucosal tumor. Precise diagnosis is possible after removal of the detected lesion. Endoscopic removal is recommended as a safe and efficient method of the treatment. In this report the authors present a case of inflammatory fibroid polyp located in the cardia, which has been removed endoscopically. Twelve months later, recurrence of the lesion was noted and the patient was referred to surgical resection.

Endoscopic sphincterotomy in 100 patients scheduled for laparoscopic cholecystectomy: ultrasound evaluation.

BACKGROUND/AIMS: The aim of the study was to determine to what extent ultrasonography may monitor the process of sphincterotomy and its effectiveness. The study also aimed at determining the sensitivity and specificity of ultrasonography in detecting choledocholithiasis, in comparison with the results of endoscopic retrograde cholangiopancreatography. METHODOLOGY: Between January 1995 and June 2001, endoscopic sphincterotomy was performed on 100 patients with suspected synchronous choledocholithiasis in preparation for laparoscopic cholecystectomy. The main parameters evaluated in the ultrasonography image included the breadth of the common bile duct and absence or presence of concrements in bile ducts before and after sphincterotomy. RESULTS: Applied before the endoscopic operation, ultrasonography revealed choledocholithiasis in 58 patients and dilatation of the common bile duct in 95 patients. Endoscopic retrograde cholangiopancreatography confirmed choledocholithiasis in 74 patients, after sphincterotomy concrements were removed in 63 persons. In 26 patients sphincterotomy was performed for stenosis of Vater's papilla. Patients with the breadth of the duct > 10 mm, were referred to a check-up examination. CONCLUSIONS: Compared with endoscopic retrograde cholangiopancreatography, ultrasonography correctly specifies the breadth of the bile duct and properly monitors the process of endoscopic sphincterotomy, but is less accurate in determining the occurrence of choledocholithiasis, and sensitivity in the test amounted to 73%, and specificity of the examination--84.5%.

Ectopic pancreas: endoscopic, ultrasound and radiological features.

Ectopic pancreas, a rare entity, is defined as pancreatic tissue lying outside its normal location without anatomical or vascular connections with the pancreas proper. Most occurrences of heterotopic pancreas are located in the stomach wall, duodenum, small intestine or anywhere in the gastrointestinal tract. The aim of this study was to describe the endoscopic, endosonographic (EUS) and radiological features of these lesions. Management of the ectopic pancreas remains controversial. The authors describe 12 patients and try to recommend different kind of treatment in the light of the symptoms, location and size of the lesions.

The influence of adenosine A3 receptor agonist: IB-MECA, on scopolamine- and MK-801-induced memory impairment.

The effects of adenosine A3 agonist IB-MECA on scopolamine- and MK-801-induced impairment of spontaneous alternation and learning abilities were examined using Y-maze and passive avoidance tasks in mice. IB-MECA given 20 min before test had no effect on spontaneous alternation performance. Similarly learning abilities tested in passive avoidance were not disturbed after IB-MECA administration before training session. IB-MECA significantly diminished scopolamine- and MK-801-induced impairment of spontaneous alternation in Y-maze and learning abilities in passive avoidance task as well as reduced higher locomotor activity in MK-801-treated group. This ameliorating effect of IB-MECA was not antagonised by adenosine A1 antagonists CPX. Obtained results indicate that adenosine A3 receptor stimulation may ameliorate spatial memory and long term memory impairments in terms of cholinergic and glutamatergic deficits induced by scopolamine and MK-801, respectively.