[Three Cases of Appendiceal Goblet Cell Adenocarcinoma in Our Institution].

Appendiceal goblet cell adenocarcinoma(AGCA)is a newly designated pathological term adopted in the 5th edition of the WHO classification. It is synonymous with goblet cell carcinoid, which was previously categorized as a part of appendiceal carcinoid. However, since 2018, it has been classified as a subtype of adenocarcinoma. We have experienced 3 cases of this relatively rare tumor, of which 2 were initially diagnosed with acute appendicitis and were diagnosed with AGCA by pathological examination after an emergency appendectomy. Each of them underwent additional ileocolic resection with lymph node dissection as the second surgery. In the 3rd case, an appendiceal tumor was detected during preoperative examinations for an ovarian tumor. Staging laparoscopy revealed comorbid peritoneal dissemination, and only the appendix and right ovary were removed in the consecutive surgery. The ovarian tumor was pathologically diagnosed as a metastasis of AGCA. In this case, the introduction of oxaliplatin-based systemic chemotherapy after surgery achieved a complete response after more than 2 years. Although no recurrence has been observed in all 3 cases to date, AGCA is considered highly malignant compared to conventional appendiceal carcinoids. Therefore, it is crucial to practice multidisciplinary treatments, including sufficient radical surgery based on a precise diagnosis of AGCA, as is performed for advanced colorectal cancer.

Benefit of Continuation of Low-Dose Imatinib for Gastrointestinal Stromal Tumors despite Adverse Events with Regular-Dose Imatinib.

Tyrosine kinase inhibitors (TKIs) such as imatinib improve the prognosis of patients with gastrointestinal stromal tumors (GISTs). However, treatment options for GISTs are still limited, and the continuation of TKIs is difficult due to adverse events in some cases. The effectiveness of low-dose imatinib is unclear. We report 2 cases to show effectiveness of low-dose imatinib in patients with adverse events. The first case is a male in his early 60s with a history of intestinal GIST resection who was diagnosed with recurrent GIST with peritoneal dissemination. He was started on low-dose imatinib (300 mg) because of a history of subconjunctival hemorrhage after receiving postoperative imatinib. Follow-up contrast-enhanced ultrasonography revealed that the tumors had shrunk in size and number after 2 months of treatment with 300-mg imatinib. He continued this treatment and showed partial response for 8 months. The second case is a female in her late 70s with rectal GIST who was treated with imatinib 400 mg. Due to a severe skin lesion, she changed her treatment to sunitinib 2 months after initiation. However, new metastasis in the liver was confirmed after 4 months of administration of sunitinib. She underwent surgical esection of the rectal tumor to reduce the volume. After the surgery, low-dose imatinib (300 mg) with oral steroids was adopted. Follow-up confirmed the absence of recurrence at the rectum and no increase in hepatic tumor size for 18 months. Aggressive treatment with low-dose imatinib instead of discontinuation or alteration of treatment may benefit patients with unresectable and postoperative GISTs with sensible mutation to imatinib.

Asymptomatic gangrenous cholecystitis diagnosed using contrast-enhanced ultrasonography in a patient with pancreatic cancer.

A 72-year-old female without abdominal symptoms visited our hospital for routine follow-up while undergoing pancreatic cancer treatment (using TS-1). Her vital signs were normal, and her abdomen was soft and non-tender. Blood test revealed elevated C-reactive protein levels with normal white blood cell count. Computed tomography was performed for follow-up of pancreatic cancer. Contrast-enhanced computed tomography showed partial discontinuity and irregular thickness of the gallbladder wall; however, a definitive diagnosis was not obtained due to unclear imaging. Contrast-enhanced transabdominal ultrasonography revealed intraluminal membranes in the gallbladder and a perfusion defect at the bottom, indicating gangrenous cholecystitis. Surgical resection was performed, and pathological examination showed severe necrosis of the gallbladder wall, consistent with the findings of contrast-enhanced transabdominal ultrasonography.

Primary Epstein-Barr virus infection shortly after primary Cytomegalovirus infection: a case report.

BACKGROUND: Infectious mononucleosis (IM) and mononucleosis-like illnesses are common viral infectious diseases which are often accompanied by a high fever, pharyngitis and lymphadenopathy in adults, although such infection in childhood is generally subclinical. Most cases of IM are caused by the Epstein-Barr virus (EBV) or Cytomegalovirus (CMV). However, it is difficult to diagnose IM only with subjective symptoms, and thus EBV and CMV are nearly indistinguishable in clinical practice. CASE PRESENTATION: A 20-year-old healthy Japanese woman had a 2-day history of high fever and consulted us. She had sex for the first time 6 months earlier. Her virus antibodies showed that she was infected with primary CMV. About 5 months later, she again experienced high fever and lymph node enlargement at the posterior cervical region. Her virus antibodies showed that she was infected with primary EBV at that time. CONCLUSION: Herein, we report a healthy adult Japanese woman with primary EBV infection relatively soon after primary CMV infection. It is very interesting to compare the symptoms and/or clinical data after EBV and CMV infection in the same patient within a short period of time. Our patient was diagnosed based only on subjective symptoms, physical examination and laboratory data, without tests of such virus-related antibodies. Therefore, clinicians should bear in mind that primary EBV infection and/or primary CMV infection is possible when patients have symptoms such as high fever, pharyngitis and lymphadenopathy, even in healthy adults.

Angiopoietin-like protein 2 promotes chronic adipose tissue inflammation and obesity-related systemic insulin resistance.

Recent studies of obesity have provided new insights into the mechanisms underlying insulin resistance and metabolic dysregulation. Numerous efforts have been made to identify key regulators of obesity-linked adipose tissue inflammation and insulin resistance. We found that angiopoietin-like protein 2 (Angptl2) was secreted by adipose tissue and that its circulating level was closely related to adiposity, systemic insulin resistance, and inflammation in both mice and humans. Angptl2 activated an inflammatory cascade in endothelial cells via integrin signaling and induced chemotaxis of monocytes/macrophages. Constitutive Angptl2 activation in vivo induced inflammation of the vasculature characterized by abundant attachment of leukocytes to the vessel walls and increased permeability. Angptl2 deletion ameliorated adipose tissue inflammation and systemic insulin resistance in diet-induced obese mice. Conversely, Angptl2 overexpression in adipose tissue caused local inflammation and systemic insulin resistance in nonobese mice. Thus, Angptl2 is a key adipocyte-derived inflammatory mediator that links obesity to systemic insulin resistance.

CRMP-2 directly binds to cytoplasmic dynein and interferes with its activity.

The active transport of proteins and organelles is critical for cellular organization and function in eukaryotic cells. A substantial portion of long-distance transport depends on the opposite polarity of the kinesin and dynein family molecular motors to move cargo along microtubules. It is increasingly clear that many cargo molecules are moved bi-directionally by both sets of motors; however, the regulatory mechanism that determines the directionality of transport remains unclear. We previously reported that collapsin response mediator protein-2 (CRMP-2) played key roles in axon elongation and neuronal polarization. CRMP-2 was also found to associate with the anterograde motor protein Kinesin-1 and was transported with other cargoes toward the axon terminal. In this study, we investigated the association of CRMP-2 with a retrograde motor protein, cytoplasmic dynein. Immunoprecipitation assays showed that CRMP-2 interacted with cytoplasmic dynein heavy chain. Dynein heavy chain directly bound to the N-terminus of CRMP-2, which is the distinct side of CRMP-2's kinesin light chain-binding region. Furthermore, over-expression of the dynein-binding fragments of CRMP-2 prevented dynein-driven microtubule transport in COS-7 cells. Given that CRMP-2 is a key regulator of axon elongation, this interference with cytoplasmic dynein function by CRMP-2 might have an important role in axon formation, and neuronal development.

Angiopoietins contribute to lung development by regulating pulmonary vascular network formation.

Angiopoietin (Ang) signaling through the Tie2 receptor regulates vasculature. The role of Ang signaling in pulmonary hypertension is well investigated, but its role in lung development is not elucidated. Here, we show that the Tie2 agonist ligand, Ang1, was detected in lung tissue at birth and its expression gradually increased in mice, whereas its antagonist Ang2 was abundant at birth and decreased inversely with Ang1. Mice expressing the potent chimeric Ang1 protein COMP-Ang1 in surfactant protein C (SPC)-positive lung epithelial cells, showed 50% lethality at birth due to respiratory failure. Surviving mice displayed impaired adaptive responsive respiratory function. Histological analysis revealed that pulmonary artery and alveolar structure were significantly dilated, and alveolar density was decreased to approximately a third of controls. Thus, the precise regulation of Tie2 signaling through an Ang1/Ang2 expression switch is important to construct a mature lung vascular network system required for normal lung development.

Angiopoietin-related growth factor enhances blood flow via activation of the ERK1/2-eNOS-NO pathway in a mouse hind-limb ischemia model.

OBJECTIVE: Transgenic mice overexpressing angiopoietin-related growth factor (AGF) exhibit enhanced angiogenesis, suggesting that AGF may be a useful drug target in ischemic disease. Our goal was to determine whether AGF enhances blood flow in a mouse hind-limb ischemia model and to define molecular mechanisms underlying AGF signaling in endothelial cells. METHODS AND RESULTS: Intramuscular injection of adenovirus harboring AGF into the ischemic limb increased AGF production, which increased blood flow through induction of angiogenesis and arteriogenesis, thereby reducing the necessity for limb amputation. In vitro analysis showed that exposing human umbilical venous endothelial cells to AGF increased nitric oxide (NO) production through activation of an ERK1/2-endothelial NO synthetase (eNOS) signaling pathway. AGF-stimulated eNOS phosphorylation, NO production, and endothelial cell migration were all abolished by specific MEK1/2 inhibitors. Moreover, AGF did not restore blood flow to ischemic hind-limbs of either mice receiving NOS inhibitor L-NAME or eNOS knockout mice. CONCLUSIONS: Activation of an ERK1/2-eNOS-NO pathway is a crucial signaling mechanism by which AGF increases blood flow through induction of angiogenesis and arteriogenesis. Further investigation of the regulation underlying AGF signaling pathway may contribute to develop a new clinical strategy for ischemic vascular diseases.

Angiotensin II type 1 receptor-mediated inflammation is required for choroidal neovascularization.

BACKGROUND: Choroidal neovascularization (CNV) is a critical pathogenesis in age-related macular degeneration, the most common cause of blindness in the developed countries. The aim of the current study was to determine the involvement of the renin-angiotensin system (RAS) with the development of CNV, using human surgical samples and the murine model of laser-induced CNV. METHODS AND RESULTS: In the human and murine CNV tissues, the vascular endothelium expressed angiotensin II type 1 receptor (AT1-R), AT2-R, and angiotensin II. The CNV volume was significantly suppressed by treatment with an AT1-R blocker telmisartan, but not with an AT2-R blocker. AT1-R signaling blockade with telmisartan inhibited various inflammatory mechanisms including macrophage infiltration and upregulation of VEGF, intercellular adhesion molecule-1 (ICAM-1), MCP-1, and IL-6 in the retinal pigment epithelium-choroid complex. A PPAR-gamma antagonist partially but significantly reversed the suppressive effect of telmisartan on in vivo induction of CNV and in vitro upregulation of ICAM-1 and MCP-1 in endothelial cells and IL-6 in macrophages, showing the dual contribution of PPAR-gamma-agonistic and AT1-R-antagonistic actions in the telmisartan treatment. CONCLUSIONS: AT1-R-mediated inflammation plays a pivotal role in the development of CNV, indicating the possibility of AT1-R blockade as a novel therapeutic strategy to inhibit CNV.

Angiopoietins and angiopoietin-like proteins in angiogenesis.

Vascular network formation requires several endothelial cell growth factors. These factors have a potent angiogenic effect, and their precise coordination is essential for vascular development. Among them, angiopoietins function through the Tie2 receptor, whose signaling is critical to regulate vascular stabilization and remodeling. It has been reported that the angiopoietin/Tie2 signal is involved in survival and migration of endothelial cells and regulates vascular remodeling and maintenance of vascular integrity. More recent studies demonstrate that angiopoietin/Tie2 signaling is also required for lymphangiogenesis. The authors and several other groups have identified six angiopoietin-like proteins (Angptls) containing a coiled-coil domain and a fibrinogen-like domain, both of which are characteristic of angiopoietins. Interestingly, Angptls also function in angiogenesis through regulating survival and migration of endothelial cells, although Angptls do not bind the angiopoietin receptor Tie2. Currently, Angptls are orphan ligands, but they have been reported to have pleiotropic effects not only on vascular cells but also on metabolism and tumor biology. Here, the authors review current findings relating to the roles of angiopoietins and Angptls in vascular biology and discuss molecular mechanisms relevant to these factors and angiogenesis.

Cooperative interaction of Angiopoietin-like proteins 1 and 2 in zebrafish vascular development.

Angiopoietin-like protein (Angptl) 1 and Angptl2, which are considered orphan ligands, are highly homologous, particularly in the fibrinogen-like domain containing the putative receptor binding site. This similarity suggests potentially cooperative functions between the two proteins. In this report, the function of Angptl1 and Angptl2 is analyzed by using morpholino antisense technology in zebrafish. Knockdown of both Angptl1 and Angptl2 produced severe vascular defects due to increased apoptosis of endothelial cells at the sprouting stage. In vitro studies showed that Angptl1 and Angptl2 have antiapoptotic activities through the phosphatidylinositol 3-kinase/Akt pathway, and coinjection of constitutively active Akt/protein kinase B mRNA rescued impaired vascular development seen in double knockdown embryos. These results provide a physiological demonstration of the cooperative interaction of Angptl1 and Angptl2 in endothelial cells through phosphatidylinositol 3-kinase/Akt mediated antiapoptotic activities.

Suppression of ocular inflammation in endotoxin-induced uveitis by blocking the angiotensin II type 1 receptor.

PURPOSE: To examine whether the angiotensin II type 1 receptor (AT1-R) signaling plays a role in ocular inflammation in endotoxin-induced uveitis (EIU). METHODS: EIU was induced in C57BL/6 mice by a single intraperitoneal injection of 150 mug lipopolysaccharide (LPS). Tissue localization, mRNA expression, and protein levels of AT1-R in murine retinas were examined by immunohistochemistry, RT-PCR, and Western blot analyses, respectively. Telmisartan, an AT1-R antagonist widely used as an antihypertensive agent, was administered intraperitoneally at a dose of 10 mg/kg daily for 5 days until the injection of LPS. Twenty-four hours after administration, leukocyte adhesion to the retinal vasculature was evaluated with a concanavalin A lectin perfusion-labeling technique. Retinal mRNA and protein levels of intercellular adhesion molecule (ICAM)-1 were examined by RT-PCR and ELISA, respectively. Protein concentration and inflammatory cells in the aqueous humor were also measured. RESULTS: Retinal vessels were positive for AT1-R. In mice with EIU, retinal AT1-R mRNA and protein levels were significantly increased when compared to the normal control. EIU animals also showed significant increases in the number of inflammatory cells infiltrating the anterior chamber and adhering to the retinal vessels and in retinal ICAM-1 levels. Administration of telmisartan to EIU mice resulted in significant suppression of retinal ICAM-1 expression and leukocyte adhesion and infiltration compared with vehicle treatment. Protein concentration in the aqueous humor of telmisartan-treated EIU mice tended to be lower than that of vehicle-treated EIU mice, but the difference was not statistically significant. CONCLUSIONS: AT1-R signaling blockade inhibited retinal ICAM-1 upregulation and leukocyte adhesion and infiltration in the EIU model. These results suggest the potential use of an AT1-R antagonist as a therapeutic agent to reduce ocular inflammation.

Isolation and expression patterns of genes for three angiopoietin-like proteins, Angptl1, 2 and 6 in zebrafish.

Angiopoietin-like proteins (Angptls) are known to possess biological activities not only in the vascular system, but in the other mammalian tissues; however, their expression patterns and function in embryogenesis have not been extensively characterized. Here, we identify three zebrafish genes (Zangptl1, Zangptl2 and Zangptl6) highly homologous to mammalian Angptl1/ARP1, Angptl2/ARP2 and Angptl6/AGF, and describe their adult and embryonic temporal and spatial expression patterns. Zangptl1 is expressed faintly in the somites, while Zangptl2 is first detected in the yolk sac extension, spinal cord and branchial arches and is later expressed in the liver primordium and pectoral fin buds. Zangptl6 is expressed in the notochord. In addition to its embryonic expression, Zangptl2 is induced in adult fish during fin regeneration.

Angiopoietin-related growth factor antagonizes obesity and insulin resistance.

Angiopoietin-related growth factor (AGF), a member of the angiopoietin-like protein (Angptl) family, is secreted predominantly from the liver into the systemic circulation. Here, we show that most (>80%) of the AGF-deficient mice die at about embryonic day 13, whereas the surviving AGF-deficient mice develop marked obesity, lipid accumulation in skeletal muscle and liver, and insulin resistance accompanied by reduced energy expenditure relative to controls. In parallel, mice with targeted activation of AGF show leanness and increased insulin sensitivity resulting from increased energy expenditure. They are also protected from high-fat diet-induced obesity, insulin resistance and nonadipose tissue steatosis. Hepatic overexpression of AGF by adenoviral transduction, which leads to an approximately 2.5-fold increase in serum AGF concentrations, results in a significant (P < 0.01) body weight loss and increases insulin sensitivity in mice fed a high-fat diet. This study establishes AGF as a new hepatocyte-derived circulating factor that counteracts obesity and related insulin resistance.

Angiopoietin-1 promotes LYVE-1-positive lymphatic vessel formation.

Angiopoietin (Ang) signaling plays a role in angiogenesis and remodeling of blood vessels through the receptor tyrosine kinase Tie2, which is expressed on blood vessel endothelial cells (BECs). Recently it has been shown that Ang-2 is crucial for the formation of lymphatic vasculature and that defects in lymphangiogenesis seen in Ang-2 mutant mice are rescued by Ang-1. These findings suggest important roles for Ang signaling in the lymphatic vessel system; however, Ang function in lymphangiogenesis has not been characterized. In this study, we reveal that lymphatic vascular endothelial hyaluronan receptor 1-positive (LYVE-1(+)) lymphatic endothelial cells (LECs) express Tie2 in both embryonic and adult settings, indicating that Ang signaling occurs in lymphatic vessels. Therefore, we examined whether Ang-1 acts on in vivo lymphatic angiogenesis and in vitro growth of LECs. A chimeric form of Ang-1, cartilage oligomeric matrix protein (COMP)-Ang-1, promotes in vivo lymphatic angiogenesis in mouse cornea. Moreover, we found that COMP-Ang-1 stimulates in vitro colony formation of LECs. These Ang-1-induced in vivo and in vitro effects on LECs were suppressed by soluble Tie2-Fc fusion protein, which acts as an inhibitor by sequestering Ang-1. On the basis of these observations, we propose that Ang signaling regulates lymphatic vessel formation through Tie2.

Selective suppression of pathologic, but not physiologic, retinal neovascularization by blocking the angiotensin II type 1 receptor.

PURPOSE: To investigate the anti-inflammatory and anti-angiogenic effects of telmisartan, an angiotensin II type 1 receptor (AT1-R) antagonist, on ischemia-induced retinal neovascularization. METHODS: C57BL/6 neonatal mice were reared in an 80% concentration of oxygen from postnatal day (P)7 to P12, followed by room-air breathing until P17, to induce ischemia-initiated retinal neovascularization (i.e., a murine model of ischemic retinopathy). Tissue localization of AT1-R was examined by immunohistochemistry for murine retinal wholemounts and human fibrovascular tissues excised at vitrectomy for proliferative diabetic retinopathy. Animals received intraperitoneal injection of telmisartan or vehicle. A concanavalin A lectin perfusion-labeling technique was used to evaluate the areas of physiological and pathologic retinal new vessels and the number of leukocytes adhering to the vasculature. Retinal mRNA and protein levels of intercellular adhesion molecule (ICAM)-1, vascular endothelial growth factor receptor (VEGFR)-1, and VEGFR-2 were examined by RT-PCR and ELISA. RESULTS: Vessels in human fibrovascular tissues and the murine retinas were positive for AT1-R. Pathologic (P < 0.01), but not physiologic (P > 0.05), retinal neovascularization was significantly suppressed in telmisartan-treated mice compared with vehicle-treated animals. The number of adherent leukocytes (P < 0.01) was also significantly reduced, together with retinal ICAM-1 levels (P < 0.01) in the telmisartan-treated group compared with the control group. No significant difference was detected in retinal VEGFR-2 levels between the two groups, whereas retinal VEGFR-1 levels in the telmisartan-treated group were significantly (P < 0.05) lower than in the vehicle-treated group. CONCLUSIONS: The present findings suggest that the AT1-R signaling blockade leads to the selective suppression of pathologic, but not physiological, retinal neovascularization through the inhibition of the inflammatory processes related to pathologic neovascularization.

Angiopoietin-related growth factor (AGF) promotes angiogenesis.

We report here the identification of angiopoietin-related growth factor (AGF) as a positive mediator for angiogenesis. To investigate the biologic function of AGF in angiogenesis, we analyzed the vasculature in the dermis of transgenic mice expressing AGF in mouse epidermal keratinocytes (K14-AGF). K14-AGF transgenic mice were grossly red, especially in the ears and snout, suggesting that hypervascularization had occurred in their skin. Histologic examination of ear skin from K14-AGF transgenic mice revealed increased numbers of microvessels in the dermis, whereas the expression of several angiogenic factors, such as basic fibroblast growth factor (bFGF), vascular endothelial growth factors (VEGFs), and angiopoietin-1 (Ang-1), was decreased. We showed that AGF is a secreted protein and does not bind to tyrosine kinase with immunoglobulin and EGF-homology domain (Tie1) or Tie2 receptors. An in vitro chamber assay revealed that AGF directly promotes chemotactic activity of vascular endothelial cells. Both mouse corneal and matrigel plug assays showed that AGF induces neovascularization in vivo. Furthermore, we found that plasma leakage occurred after direct injection of AGF into the mouse dermis, suggesting that AGF directly induces a permeability change in the local vasculature. On the basis of these observations, we propose that AGF is a novel angiogenic factor and that handling of its biologic functions could lead to novel therapeutic strategies for control of angiogenesis.