In cancer metastasis, various environmental stressors attack the disseminating cells. The successful colonization of cancer cells in secondary sites therefore requires the ability of the cells to avoid the consequences of such exposure to the stressors. Here we show that orthotopic transplantation of a CD44 variant isoform-expressing (CD44v + ) subpopulation of 4T1 breast cancer cells, but not that of a CD44v − subpopulation, in mice results in efficient lung metastasis accompanied by expansion of stem-like cancer cells. such metastasis is dependent on the activity of the cystine transporter xCT, and the stability of this protein is controlled by CD44v. We find that epithelial splicing regulatory protein 1 regulates the expression of CD44v, and knockdown of epithelial splicing regulatory protein 1 in CD44v + cells results in an isoform switch from CD44v to CD44 standard (CD44s), leading to reduced cell surface expression of xCT and suppression of lung colonization. The epithelial splicing regulatory protein 1-CD44v-xCT axis is thus a potential therapeutic target for the prevention of metastasis.

Cancer development is often preceded by the appearance of preneoplastic lesions. In gastric carcinogenesis, chronic inflammation and histopathologic progression of the stomach epithelium lead to the development of metaplasia and eventually adenocarcinoma. The cell surface protein CD44, especially its variant isoforms (CD44v), has been implicated in metaplasia-carcinoma sequence progression in the stomach. We recently found that CD44v interacts with and stabilizes xCT, a subunit of the cystine transporter system xc(-), in cancer cells and thereby increases cystine uptake and confers resistance to various types of cellular stress in vivo. The functional relevance of CD44v and xCT in the development of preneoplastic lesions, however, has remained unknown. We have now examined the role of the CD44v-xCT system in the development of spasmolytic polypeptide-expressing metaplasia (SPEM) in mouse models of gastric carcinogenesis. CD44v was found to be expressed de novo in SPEM, and CD44v + metaplastic cells manifested upregulation of xCT expression compared with CD44v À cells. Genetic ablation of CD44 or treatment with sulfasalazine, an inhibitor of xCT-dependent cystine transport, suppressed the development of SPEM and subsequent gastric tumor growth. Therapy targeted to CD44v-xCT could thus prove effective for prevention or attenuation of the CD44v-dependent development of preneoplastic lesions and cancer. (Cancer Sci 2013; 104: 1323-1329 G astric cancer is strongly linked to inflammation and histopathologic progression of the stomach epithelium initiated by chronic infection with Helicobacter pylori. Gastric carcinogenesis triggered by infection with this bacterium is thus characterized by a transition from normal mucosa to gastritis, which then leads to metaplasia and eventually to adenocarcinoma.(1) Spasmolytic polypeptide-expressing metaplasia (SPEM) results from a metaplastic change in H. pylori-infected gastric mucosa and is observed in the mucosa adjacent to gastric adenocarcinoma. (2)(3)(4) We previously showed that prostaglandin E 2 (PGE 2 ) and the inflammatory cytokine tumor necrosis factor-a play key roles in the development of SPEM in mice.(5) More recently, interleukin-1b has been shown to initiate the development of gastric metaplasia and dysplasia in transgenic mice.(6) Although the emergence of metaplasia or dysplasia is a key event in inflammation-related gastric carcinogenesis, the molecular mechanism underlying the development of such preneoplastic lesions is largely unknown.A major adhesion molecule for the ECM, CD44, has been implicated in a wide variety of physiological processes, including leukocyte homing and activation, wound healing, and cell migration, as well as in tumor cell invasion and metastasis. (7)(8)(9)(10) CD44 is expressed at a higher level in gastric epithelial cells isolated from the non-cancerous stomach of H. pylori-positive individuals than in those from H. pylori-negative individuals.(11) Furthermore, the abundance of CD44 mRNA has been found to be increased in gastric tissue...

We report a case of chylothorax treated successfully by a new diagnostic tool: indocyanine green (ICG) fluorescence lymphography. The patient, a 65-year-old man with adenocarcinoma of the esophagogastric junction, underwent radical esophagectomy, which was followed by the development of chylothorax. On postoperative day 10, we performed transabdominal ligation of the thoracic duct. During the re-operation, we injected ICG into the mesentery of the small bowel. We then performed mass ligation of the tissue right and dorsal of the aorta, including the thoracic duct, after which a near-infrared camera system revealed a fluorescent stripe on the caudal part of the ligation. The remnant thoracic duct appeared to be dilated as a result of lymphatic stasis. The patient was discharged 35 days after his initial surgery. We report this case to demonstrate the usefulness of intraoperative ICG lymphography as a tool to identify and confirm ligation of the thoracic duct transabdominally.

As the complexity of targeted molecules increases in modern organic synthesis, chemoselectivity is recognized as an important factor in the development of new methodologies. Chemoselective nucleophilic addition to amide carbonyl centers is a challenge because classical methods require harsh reaction conditions to overcome the poor electrophilicity of the amide carbonyl group. We have successfully developed a reductive nucleophilic addition of mild nucleophiles to tertiary amides, secondary amides, and N-methoxyamides that uses the Schwartz reagent [Cp2 ZrHCl]. The reaction took place in a highly chemoselective fashion in the presence of a variety of sensitive functional groups, such as methyl esters, which conventionally require protection prior to nucleophilic addition. The reaction will be applicable to the concise synthesis of complex natural alkaloids from readily available amide groups.

We report a rare male case of an undifferentiated carcinoma with osteoclast-like giant cells originating in an indeterminate mucin-producing cystic neoplasm of the pancreas. A 59-year-old Japanese man with diabetes visited our hospital, complaining of fullness in the upper abdomen. A laboratory analysis revealed anemia (Hemoglobin; 9.7 g/dl) and elevated C-reactive protein (3.01 mg/dl). Carbohydrate antigen 19-9 was 274 U/ml and Carcinoembryonic antigen was 29.6 ng/ml. A computed tomography scan of the abdomen revealed a 14-cm cystic mass in the upper left quadrant of the abdomen that appeared to originate from the pancreatic tail. The patient underwent distal pancreatectomy/splenectomy/total gastrectomy/cholecystectomy. The mass consisted of a multilocular cystic lesion. Microscopically, the cyst was lined by cuboidal or columnar epithelium, including mucinous epithelium. Sarcomatous mononuclear cells and multinucleated osteoclast-like giant cells were found in the stroma. Ovarian-type stroma was not seen. We made a diagnosis of osteoclast-like giant cell tumor originating in an indeterminate mucin-producing cystic neoplasm of the pancreas. All surgical margins were negative, however, two peripancreatic lymph nodes were positive. The patient recovered uneventfully. Two months after the operation, multiple metastases occurred in the liver. He died 4 months after the operation.