STAT1-mediated induction of Ly6c-expressing macrophages are involved in the pathogenesis of an acute colitis model.

BACKGROUND: The development of inflammatory bowel diseases is thought to be multifactorial, but the exact steps in pathogenesis are poorly understood. In this study, we investigated involvement of the activation of STAT1 signal pathway in the pathogenesis of an acute colitis model. METHODS: A dextran sulfate sodium-induced acute colitis model was established by using wild-type C57BL/6 mice and STAT1-deficient mice. Disease indicators such as body weight loss and clinical score, induction of cytokines, chemokines, and inflammatory cells were evaluated in the acute colitis model. RESULTS: Disease state was significantly improved in the acute colitis model using STAT1-deficient mice compared with wild-type mice. The induction of Ly6c-highly expressing cells in colorectal tissues was attenuated in STAT1-deficient mice. IL-6, CCL2, and CCR2 gene expressions in Ly6c-highly expressing cells accumulated in the inflamed colon tissues and were significantly higher than in Ly6c-intermediate-expressing cells, whereas TNF-α and IFN-α/ß gene expression was higher in Ly6c-intermediate-expressing cells. Blockade of CCR2-mediated signaling significantly reduced the disease state in the acute colitis model. CONCLUSIONS: Two different types of Ly6c-expressing macrophages are induced in the inflamed tissues through the IFN-α/ß-STAT1-mediated CCL2/CCR2 cascade and this is associated with the pathogenesis such as onset, exacerbation, and subsequent chronicity of acute colitis.

IFN-α/ß-mediated NK2R expression is related to the malignancy of colon cancer cells.

Neurokinin 2 receptor (NK2R), a G protein-coupled receptor for neurokinin A (NKA), a tachykinin family member, regulates various physiological functions including pain response, relaxation of smooth muscle, dilation of blood vessels, and vascular permeability. However, the precise role and regulation of NK2R expression in cancer cells have not been fully elucidated. In this study, we found that high NK2R gene expression was correlated with the poor survival of colorectal cancer patients, and Interferon (IFN-α/ß) stimulation significantly enhanced NK2R gene expression level of colon cancer cells in a Janus kinas 1/2 (JAK 1/2)-dependent manner. NKA stimulation augmented viability/proliferation and phosphorylation of Extracellular-signal-regulated kinase 1/2 (ERK1/2) levels of IFN-α/ß-treated colon cancer cells and NK2R blockade by using a selective antagonist reduced the proliferation in vitro. Administration of an NK2R antagonist alone or combined with polyinosinic-polycytidylic acid, a synthetic analog of double-stranded RNA, to CT26-bearing mice significantly suppressed tumorigenesis. NK2R-overexpressing CT26 cells showed enhanced tumorigenesis and metastatic colonization in both lung and liver after the inoculation into mice. These findings indicate that IFN-α/ß-mediated NK2R expression is related to the malignancy of colon cancer cells, suggesting that NK2R blockade may be a promising strategy for colon cancers.

[Long-Term Response of Nivolumab for Peritoneal Dissemination and Recurrent Liver Metastasis after Surgery for Perforated Gastric Cancer-A Case Report].

A 39-year-old woman was hospitalized because of lower abdominal pain and fatigue. A laboratory study indicated severe anemia(hemoglobin 2.5 g/dL). Computed tomography(CT)revealed a perforated gastric tumor and free air. Distal gastrectomy was performed as an emergency surgery. Histopathologic examination showed adenocarcinoma(moderately differentiated > poorly differentiated), and she was diagnosed as having a pT4b, pN0, pM1, pStage ⅣB tumor. Postoperatively, adjuvant chemotherapy with S-1 was administered. CT imaging 2 years after the operation showed peritoneal dissemination and liver metastasis, and XELOX therapy was initiated. Response evaluation after 3 courses was progressive disease (PD), and ramucirumab plus paclitaxel was initiated. After 5 courses, CT imaging revealed ascites and progression of peritoneal dissemination and liver metastasis; nivolumab was initiated. CT imaging after 74 courses showed peritoneal dissemination, and liver metastasis became unclear. The patient at present has responded well to nivolumab for 52 months.

Combined treatment of an aortosplenic bypass followed by coil embolization in the treatment of pancreaticoduodenal artery aneurysms caused by median arcuate ligament compression: a report of two cases.

BACKGROUND: Pancreaticoduodenal artery aneurysms (PDAAs) are rare visceral aneurysms, and prompt intervention/treatment of all PDAAs is recommended at the time of diagnosis to avoid rupture of aneurysms. Herein, we report two cases of PDAA caused by the median arcuate ligament syndrome, treated with surgical revascularization by aortosplenic bypass followed by coil embolization. CASE PRESENTATION: Case 1 A 54-year-old woman presented with a chief complaint of severe epigastralgia and was diagnosed with two large fusiform inferior PDAAs and celiac axis occlusion. To preserve the blood flow of the pancreatic head, duodenum, liver, and spleen, we performed elective surgery to release the MAL along with aortosplenic bypass. At 6 days postoperatively, transcatheter arterial embolization was performed. At the 8-year 6-month follow-up observation, no recurrent perfusion of the embolized PDAAs or rupture had occurred, including the non-embolized small PDAA, and the bypass graft had excellent patency. Case 2 A 39-year-old man who had been in good health was found to have a PDAA with celiac stenosis during a medical checkup. Computed tomography and superior mesenteric arteriography showed severe celiac axis stenosis and a markedly dilated pancreatic arcade with a large saccular PDAA. To preserve the blood flow of the pancreatic arcade, we performed elective surgery to release the MAL along with aortosplenic bypass. At 9 days postoperatively, transcatheter arterial embolization was performed. At the 6-year 7-month follow-up observation, no recurrent perfusion or rupture of the PDAA had occurred, and the bypass graft had excellent patency. CONCLUSION: Combined treatment with bypass surgery and coil embolization can be an effective option for the treatment of PDAAs associated with celiac axis occlusion or severe stenosis.

[Long-Term Survival of a Patient with Colon Cancer with Peritoneal Dissemination].

This case involves a 76 year-old woman. A sigmoidectomy was performed for sigmoid colon cancer in August 2006. On histological examination, the cancer was shown to be tub2>tub1>por2, pSE, int, INF b, ly2, v0, pN0, p1 (Douglas), Stage Ⅳ. After surgery, 4 courses of FOLFOX and 8 courses of TS-1 plus CPT-11 were administered after UFT plus LV was performed. Because of suspected recurrence at the anastomotic site, a partial colectomy was performed in September 2010, and TS-1 was started after surgery. In March 2012, the carcinoembryonic antigen level had increased to 13.7 ng/mL. Irregular masses with spicula, 13×15 mm and 19×23 mm on the right and left sides, respectively, were observed on chest computed tomography, and lung metastasis was suspected. Left lower and partial right middle lobectomies were performed. After surgery, the tumor marker levels were normalized. Chemotherapy was not performed. Currently, at 2 years 8 months after resection of the lung metastases, no recurrence was observed. Long-term survival in cases of colon cancer with peritoneal dissemination is rare, but multidisciplinary treatment, including surgical treatment, showed the promising possibility of long-term survival.