Perforation-free removal of gastric gastrointestinal stromal tumors: Endoscopic inversion and strangulation of muscle layer and resection (EISMR).

Endoscopic resection for GIST has become more widespread in recent years because it is less invasive than surgery. However, when endoscopic resection is performed, a full-layer resection of the gastric wall is often necessary, and extensive suturing is required if perforation occurs, which is a technically challenging procedure. Recently, we reported a new method called endoscopic inversion and strangulation of the muscle layer and resection (EISMR), which consists of endoscopically inverting the muscle layer into the gastric lumen and strangulating the muscle layer with a detachable snare, followed by resection. The study comprised five consecutive patients with gastric GIST ≤50 mm in diameter who underwent EISMR procedures. The main outcomes of the study were en bloc resection rate, R0 resection rate, procedure time, and complications. The results showed that all five patients successfully underwent complete resection without perforation, and the en bloc resection and R0 resection rates were 100%. The median procedure time was 93 min (range, 58-120 min), and there were no major complications. We concluded that EISMR would be a safe and effective technique for endoscopic resection of gastric GISTs and may be an alternative to surgery or endoscopic submucosal dissection.

The critical role of Rap1-GAPs Rasa3 and Sipa1 in T cells for pulmonary transit and egress from the lymph nodes.

Rap1-GTPase activates integrins and plays an indispensable role in lymphocyte trafficking, but the importance of Rap1 inactivation in this process remains unknown. Here we identified the Rap1-inactivating proteins Rasa3 and Sipa1 as critical regulators of lymphocyte trafficking. The loss of Rasa3 and Sipa1 in T cells induced spontaneous Rap1 activation and adhesion. As a consequence, T cells deficient in Rasa3 and Sipa1 were trapped in the lung due to firm attachment to capillary beds, while administration of LFA1 antibodies or loss of talin1 or Rap1 rescued lung sequestration. Unexpectedly, mutant T cells exhibited normal extravasation into lymph nodes, fast interstitial migration, even greater chemotactic responses to chemokines and sphingosine-1-phosphate, and entrance into lymphatic sinuses but severely delayed exit: mutant T cells retained high motility in lymphatic sinuses and frequently returned to the lymph node parenchyma, resulting in defective egress. These results reveal the critical trafficking processes that require Rap1 inactivation.

A Short-Term Model of Colitis-Associated Colorectal Cancer That Suggests Initial Tumor Development and the Characteristics of Cancer Stem Cells.

The mechanisms underlying the transition from colitis-associated inflammation to carcinogenesis and the cell origin of cancer formation are still unclear. The azoxymethane (AOM)/dextran sodium sulfate (DSS) mouse model reproduces human colitis-associated colorectal cancer. To elucidate the mechanisms of cancer development and dynamics of the linker threonine-phosphorylated Smad2/3 (pSmad2/3L-Thr)-positive cells, we explored the early stages of colitis-associated colorectal cancer in AOM/DSS mice. The AOM/DSS mice were sacrificed at 4 to 6 weeks following AOM administration. To analyze the initial lesions, immunofluorescence staining for the following markers was performed: ß-catenin, Ki67, CDK4, Sox9, Bmi1, cyclin D1, and pSmad2/3L-Thr. Micro-neoplastic lesions were flat and unrecognizable, and the uni-cryptal ones were either open to the surfaces or hidden within the mucosae. These neoplastic cells overexpressed ß-catenin, Sox9, Ki67, and Cyclin D1 and had large basophilic nuclei in the immature atypical cells. In both the lesions, pSmad2/3L-Thr-positive cells were scattered and showed immunohistochemical co-localization with ß-catenin, CDK4, and Bmi1 but never with Ki67. More ß-catenin-positive neoplastic cells of both lesions were detected at the top compared to the base or center of the mucosae. We confirmed initial lesions in the colitis-associated colorectal cancer model mice and observed results that suggest that pSmad2/3L-Thr is a biomarker for tissue stem cells and cancer stem cells.

Rap1 organizes lymphocyte front-back polarity via RhoA signaling and talin1.

Lymphocyte trafficking requires fine-tuning of chemokine-mediated cell migration. This process depends on cytoskeletal dynamics and polarity, but its regulation remains elusive. We quantitatively measured cell polarity and revealed critical roles performed by integrin activator Rap1 in this process, independent of substrate adhesion. Rap1-deficient naive T cells exhibited impaired abilities to reorganize the actin cytoskeleton into pseudopods and actomyosin-rich uropods. Rap1-GTPase activating proteins (GAPs), Rasa3 and Sipa1, maintained an unpolarized shape; deletion of these GAPs spontaneously induced cell polarization, indicative of the polarizing effect of Rap1. Rap1 activation required F-actin scaffolds, and stimulated RhoA activation and actomyosin contractility at the rear. Furthermore, talin1 acted on Rap1 downstream effectors to promote actomyosin contractility in the uropod, which occurred independently of substrate adhesion and talin1 binding to integrins. These findings indicate that Rap1 signaling to RhoA and talin1 regulates chemokine-stimulated lymphocyte polarization and chemotaxis in a manner independent of adhesion.

Establishment of a Novel Colitis-Associated Cancer Mouse Model Showing Flat Invasive Neoplasia.

BACKGROUND: Chronic inflammation, such as ulcerative colitis, increases the risk of developing colitis-associated cancers. Currently, mice administered with azoxymethane/dextran sodium sulfate are well-known models for colitis-associated cancers. Although human colitis-associated cancers are often flat lesions, most azoxymethane/dextran sodium sulfate mouse cancers are raised lesions. AIMS: To establish a novel mouse model for colitis-associated cancers and evaluate its characteristics. METHODS: A single dose of azoxymethane was intraperitoneally administered to CD4-dnTGFßRII mice, which are genetically modified mice that spontaneously develop inflammatory bowel disease at different doses and timings. The morphological and biological characteristics of cancers was assessed in these mice. RESULTS: Colorectal cancer developed with different proportions in each group. In particular, a high rate of cancer was observed at 10 and 20 weeks after administration in 12-week-old CD4-dnTGFßRII mice dosed at 15 mg/kg. Immunohistochemical staining of tumors was positive for ß-catenin, ki67, and Sox9 but not for p53. Grade of inflammation was significantly higher in mice with cancer than in those without cancer (p < 0.001). In CD4-dnTGFßRII/azoxymethane mice, adenocarcinomas with flat lesions were observed, with moderate-to-severe inflammation in the non-tumor area. In comparison, non-tumor areas of azoxymethane/dextran sodium sulfate mice had less inflammation than those of CD4-dnTGFßRII/azoxymethane mice, and most macroscopic characteristics of tumors were pedunculated or sessile lesions in azoxymethane/dextran sodium sulfate mice. CONCLUSIONS: Although feasibility and reproducibility of azoxymethane/CD4-dbTGFßRII appear to be disadvantages compared to the azoxymethane/dextran sodium sulfate model, this is the first report to demonstrate that the chronic inflammatory colitis model, CD4-dnTGFßRII also develops colitis-related colorectal cancer.

Viral Infection in Esophageal, Gastric, and Colorectal Cancer.

The human gastrointestinal tract, which constitutes the digestive system, contains a large number of virus particles that maintain organizational homeostasis and health. Conversely, viral pathogens have also attracted attention for their involvement in the pathogenesis of certain cancers, including gastrointestinal cancers. To aid prevention and treatment of these cancers, the relevance of gastrointestinal viral factors as potential risk factors needs to be carefully investigated. This review summarizes and discusses the available literature on the relationship between the development of esophageal, gastric, and colorectal cancers and their corresponding viruses. This review reveals that research on the association between colorectal cancer and viruses, in particular, is still in its infancy compared to the association between HPV and esophageal cancer and between EBV and gastric cancer.

Linker Threonine-phosphorylated Smad2/3 Is a Biomarker of Colorectal Neoplastic Stem-like Cells that Correlates With Carcinogenesis.

BACKGROUND/AIM: This study analysed threonine-phosphorylated Smad2/3 (pSmad2/3L-Thr) expression and investigated whether pSmad2/3L-Thr is related to the transition from human colorectal adenoma (CRA) to carcinoma (CRC). MATERIALS AND METHODS: Immunofluorescent staining was performed forß-catenin, p53, CDK4, Ki67, Sox9, aldehyde dehydrogenase (ALDH) 1, and pSmad2/3L-Thr. RESULTS: We analysed specimens of diffuse p53-positive CRCs arising from p53-negative CRAs. Percentage of p53, nuclear ß-catenin, Ki67, CDK4, and pSmad2/3L-Thr-positive cells at the site of CRCs was significantly higher than that at the site of CRAs. At the site of normal colorectal mucosae, few epithelial cells were stained positively for pSmad2/3L-Thr. At the site of CRCs, pSmad2/3L-Thr-positive cells showed co-localization with p53, nuclear ß-catenin, and ALDH1. At any site, pSmad2/3L-Thr-positive cells showed co-localization with CDK4. CONCLUSION: pSmad2/3L-Thr correlates with human CRC carcinogenesis, and pSmad2/3L-Thr-positive cells show human colorectal stem cell-like and cancer stem cell characteristics.

Specific Smad2/3 Linker Phosphorylation Indicates Esophageal Non-neoplastic and Neoplastic Stem-Like Cells and Neoplastic Development.

BACKGROUND: There is little known about stem cells in human non-neoplastic and neoplastic esophageal epithelia. We have demonstrated expression of linker threonine-phosphorylated Smad2/3 (pSmad2/3L-Thr), suggesting presence of stem-like cells in mouse esophageal epithelium, and identified presence of pSmad2/3L-Thr-positive cells that might function as cancer stem cells in mouse model of colorectal carcinoma. AIMS: We explore whether pSmad2/3L-Thr can be used as a biomarker for stem cells of human esophageal epithelia and/or neoplasms. METHODS: We have used esophageal tissues from inpatients undergoing endoscopic submucosal dissection and performed double immunofluorescent staining of pSmad2/3L-Thr and Ki67, CDK4, p63, Sox2, CK14, p53, ALDH1, CD44 or D2-40 after which the sections were stained with hematoxylin and eosin. RESULTS: pSmad2/3L-Thr-positive cells showed immunohistochemical co-localization with CDK4, p63, CD44 and Sox2 in the basal and parabasal layers of non-neoplastic esophageal epithelia. In esophageal neoplasms, they showed immunohistochemical co-localization with p53, CDK4, ALDH1 and CD44. There was a significant increase in the percentage of pSmad2/3L-Thr-positive cells in the p53-positive neoplastic cell population with development of esophageal neoplasia. pSmad2/3L-Thr-positive cells localized to the lower section of low-grade intraepithelial neoplasia and were observed up to the upper section in carcinoma in situ. In invasive squamous cell carcinoma, they were scattered throughout the tumor with disappearance of polarity and were found in intraepithelial primary lesions and sites of submucosal and vessel invasion. CONCLUSIONS: We determined significant expression of pSmad2/3L-Thr in human esophageal non-neoplastic and neoplastic epithelia, indicating that these are epithelial stem-like cells and cancer stem cells, respectively, that correlate with developing esophageal neoplasms.

Long-term model of colitis-associated colorectal cancer suggests tumor spread mechanism and nature of cancer stem cells.

Although chemical-induced animal models of colorectal cancer (CRC) suggest a lot about the disease, more efforts are required to establish metastasis models. Azoxymethane (AOM) and dextran sodium sulfate (DSS)-treated (AOM/DSS) Crl:CD-1 mice were sacrificed after 10 or 20 weeks in our previous study, and most colon tumors exhibited intramucosal adenocarcinomas. Our observations were extended until 30 weeks to study a colitis-associated advanced CRC mouse model, and explore whether linker threonine-phosphorylated Smad2/3 (pSmad2/3L-Thr) immunostaining-positive cells were involved in the progressive course of colitis-associated CRC as cancer stem cells. AOM/DSS mice were sacrificed at 10, 20 and 30 weeks after AOM administration. Following the histopathological analysis, immunohistochemical staining was performed for the following markers: CD34, podoplanin, ß-catenin, E-cadherin, Ki67, Bmi1 and pSmad2/3L-Thr. Compared with AOM/DSS mice at 10 and 20 weeks, submucosal tumor infiltration and tumor invasion into vessels were markedly increased at 30 weeks. In the parts of colon tumors from AOM/DSS mice, particularly in mice at 30 weeks, the positive signal of E-cadherin was clearly reduced in the cell membranes. The percentage of Ki67-positive tumor cells in mucosal areas of AOM/DSS mice was higher than that in the sites of submucosal infiltration. In mucosal areas of colon tumors, pSmad2/3L-Thr-positive cells were scattered among tumor cells. At sites of submucosal infiltration and vessel invasion of these tumors, pSmad2/3L-Thr-positive cells were also observed among tumor cells. In colon tumors from AOM/DSS mice at 30 weeks, the percentage of pSmad2/3L-Thr-positive cells among the nuclear ß-catenin-positive tumor cells was higher than that among the cytoplasmic ß-catenin-positive tumor cells. For both non-neoplastic and neoplastic epithelial cells, pSmad2/3L-Thr-positive cells exhibited immunohistochemical co-localization with Bmi1. The present study developed an advanced CRC mouse model that exhibited tumor infiltration into the submucosa and invasion into vessels. The present study re-confirmed the theory that pSmad2/3L-Thr-positive cells may be cancer stem cells.

Incidentally Detected Amyloid Light-Chain Amyloidosis Caused by Monoclonal Gammopathy of Undetermined Significance: Possible Time-Dependent Change in Colonic Findings.

Amyloid light-chain (AL) amyloidosis is associated with plasma cell disorder and monoclonal light chains. This type of amyloidosis is the prominent type involving the gastrointestinal tract. Monoclonal gammopathy of undetermined significance (MGUS) is the most common plasma cell disorder and a known precursor of more serious diseases. A 72-year-old male was treated for high blood pressure, diabetes, and gout at the clinic of a private physician. Due to a positive fecal occult blood test discovered during colon cancer screening, he underwent colonoscopy and was diagnosed with adenomatous polyps by biopsies. Two months later, he was referred to our hospital for endoscopic resection of the polyps. Although the polyps were successfully removed, a colonoscopy revealed two types of ulcerative lesions. Immunohistopathological evaluations obtained from these lesions and polyps confirmed amyloid deposition. Although esophagogastroduodenoscopy results were normal, a biopsy specimen from the patient's stomach showed the same type of amyloid deposition. Immunoelectrophoresis showed M-proteins for anti-IgG-λ in the serum and λ type Bence-Jones protein in the urine. His blood, bone marrow, and urine test results led to a diagnosis of MGUS. A coronary angiography revealed multivessel stenosis, and the patient's cardiac function improved after coronary artery stenting. Hereafter, a combination therapy with bortezomib, lenalidomide, and dexamethasone is planned. This is a case report of systemic AL amyloidosis caused by MGUS, which was incidentally detected by colonoscopy.

IgG4-related Disease Involving Multiple Organs with Elevated Serum Interleukin-6 Levels.

A 63-year-old woman presented to our hospital with elevated levels of serum IgG4, marked wall thickening of the gallbladder, hepatomegaly, and abdominal lymphadenopathy. She experienced a recurrent fever and leg edema. Her laboratory data demonstrated anemia, hypoalbuminemia, and elevated serum levels of interleukin-6 and C-reactive protein. The patient was eventually diagnosed with IgG4-related disease according to the comprehensive diagnostic criteria, although the patient exhibited common clinical manifestations of multicentric Castleman disease such as a fever, anemia, lymphadenopathy, and elevated levels of serum interleukin-6 and C-reactive protein. This case report highlights the difficulties in differentiating between these two diseases.

Successful Multidisciplinary Therapy for Small Cell Carcinomas Arising from the Extrahepatic Bile Duct.

A 74-year-old man was diagnosed with small cell carcinoma arising from the extrahepatic bile duct according to a histological examination of the biopsy specimen obtained during endoscopic retrograde cholangiopancreatography. Additionally, bulky hilar lymphadenopathy was observed, and the patient was treated with the combination of radiation and chemotherapy (cisplatin and irinotecan). Post-therapy, he underwent pancreaticoduodenectomy. The histological examination of the resected specimen revealed no residual cancer cells in the bile duct wall and a small amount of cancer cells in only a single lymph node. Due to this multidisciplinary therapy, the patient showed no signs of recurrence 12 months postoperatively.