OBJECTIVE-To examine fat biopsy samples from lean insulinsensitive and obese insulin-resistant nondiabetic individuals for evidence of endoplasmic reticulum (ER) stress.RESEARCH DESIGN AND METHODS-Subcutaneous fat biopsies were obtained from the upper thighs of six lean and six obese nondiabetic subjects. Fat homogenates were used for proteomic (two-dimensional gel and MALDI-TOF/TOF), Western blot, and RT-PCR analysis.RESULTS-Proteomic analysis revealed 19 differentially upregulated proteins in fat of obese subjects. Three of these proteins were the ER stress-related unfolded protein response (UPR) proteins calreticulin, protein disulfide-isomerase A3, and glutathione-S-transferase P. Western blotting revealed upregulation of several other UPR stress-related proteins, including calnexin, a membrane-bound chaperone, and phospho c-jun NH 2 -terminal kinase (JNK)-1, a downstream effector protein of ER stress. RT-PCR analysis revealed upregulation of the spliced form of X-box binding protein-1s, a potent transcription factor and part of the proximal ER stress sensor inositol-requiring enzyme-1 pathway.CONCLUSIONS-These findings represent the first demonstration of UPR activation in subcutaneous adipose tissue of obese human subjects. As JNK can inhibit insulin action and activate proinflammatory pathways, ER stress activation of JNK may be a link between obesity, insulin resistance, and inflammation. Diabetes 57: [2438][2439][2440][2441][2442][2443][2444] 2008 O besity is associated with insulin resistance and with a low-grade state of inflammation (1). Whereas the cause of neither is completely understood, there is good evidence to show that free fatty acids (FFAs) play an important role in the development of obesity-related insulin resistance and inflammation (2). Plasma FFA levels are increased in most obese people (3). Acutely raising plasma FFA levels increases insulin resistance (4), whereas lowering plasma FFA levels reduces insulin resistance (5). Mechanisms involved in FFAinduced insulin resistance include accumulation (in muscle and liver) of lipids and lipid intermediates, including diacylglycerol; activation of several protein kinase C isoforms; and reduction in tyrosine phosphorylation of insulin receptor substrate-1/2 (6 -8). FFAs also activate the proinflammatory nuclear factor B pathway (6,9), in part, via signaling through toll-like receptor-4 pathways (10). However, not all obese, insulin-resistant subjects have elevated plasma FFA levels. It is therefore likely that there are other causes for obesityrelated insulin resistance. One of these appears to be endoplasmic reticulum (ER) stress. Indeed, chronic excessive nutrient intake has been shown to cause ER stress in adipose tissue of ob/ob mice and mice fed high-fat diets (11-13).The ER is a major site for protein as well as for lipid and sterol synthesis (14,15). Ribosomes attached to the ER membranes release newly synthesized peptides into the ER lumen, where protein chaperones and foldases assist in the proper posttranslational modification a...

While the epidemiologic association between hepatitis B virus (HBV) infection and diffuse large B-cell lymphoma (DLBCL) is established, little is known more than this epidemiologic evidence. We studied a cohort of 587 patients with DLBCL for HBV infection status, clinicopathologic features, and the immunoglobulin variable region in HBV surface antigen (HBsAg)-positive patients. Eighty-one (81/587, 13.8%) patients were HBsAg-positive. Compared with HBsAg-negative DLBCL, HBsAg-positive DLBCL displayed a younger median onset age (45 vs. 55 years), more frequent involvement of spleen or retroperitoneal lymph node (40.7% vs. 16.0% and 61.7% vs. 31.0% respectively, both p < 0.001), more advanced disease (stage III/IV: 76.5% vs 59.5%, p = 0.003), and significantly worse outcome (2-year overall survival: 47% versus 70%, p < 0.001). In HBsAg-positive DLBCL patients, almost all (45/47, 96%) amino acid sequences of heavy and light chain complementarity determining region 3 exhibited a high homology to antibodies specific for HBsAg, and the majority (45/50, 90%) of IgHV and IgLV genes were mutated. We conclude that 13.8% of DLBCL cases are HBV-associated in HBV-endemic China and show unique clinical features and poor outcomes. Furthermore, our study strongly suggests that HBV-associated DLBCL might arise from HBV antigen-selected B cells.

BackgroundEndometrial cancer is one of the most common gynecological malignancies and has exhibited an increasing incidence rate in recent years. Cancer stem cells (CSCs), which are responsible for tumor growth and chemoresistance, have been confirmed in endometrial cancer. However, it is still challenging to identify endometrial cancer stem cells to then target for therapy.MethodsFlow cytometry was used to identify the endometrial cancer stem cells. Sphere formation assay, western blotting, qRT-PCR assay, cell viability assay, xenograft assay and immunohistochemistry staining analysis were utilized to evaluate the effect of SPARC-related modular calcium binding 2 (SMOC-2) on the cells proliferation and drug resistance. Cell viability assay, qRT-PCR assay, immunofluorescence staining, Co-IP assay and luciferase reporter gene assay were performed to explore the possible molecular mechanism by which SMOC-2 activates WNT/β-catenin pathway.FindingsWe found the expression of SPARC-related modular calcium binding 2 (SMOC-2), a member of SPARC family, was higher in endometrial CSCs than that in non-CSCs. SMOC-2 was also more highly expressed in spheres than in monolayer cultures. The silencing of SMOC-2 suppressed cell sphere ability; reduced the expression of the stemness-associated genes SOX2, OCT4 and NANOG; and enhanced chemosensitivity in endometrial cancer cells. By co-culture IP assay, we demonstrated that SMOC-2 directly interacted with WNT receptors (Fzd6 and LRP6), enhanced ligand-receptor interaction with canonical WNT ligands (Wnt3a and Wnt10b), and finally, activated the WNT/β-catenin pathway in endometrial cancer. SMOC-2 expression was closely correlated with CSC markers CD133 and CD44 expression in endometrial cancer tissue.InterpretationTaken together, we conclude that SMOC-2 might be a novel endometrial cancer stem cell signature gene and therapeutic target for endometrial cancer.FundNational Natural Science Foundation of China, Scientific and Technological Innovation Act Program of Shanghai Science and Technology Commission, Scientific and Technological Innovation Act Program of Fengxian Science and Technology Commission, Natural Science Foundation of Shanghai.

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