A high-fat diet causes activation of the regulatory protein cJun NH 2 -terminal kinase 1 (JNK1) and triggers the development of insulin resistance.

Summary Immunotherapy is being increasingly recognized as a key therapeutic modality to treat cancer and represents one of the most exciting treatments for the disease. Fighting cancer with immunotherapy has revolutionized treatment for some patients and therapies targeting the immune checkpoint molecules such as CTLA-4 and PD-1 have achieved durable responses in melanoma, renal cancer, Hodgkin’s diseases and lung cancer. However, the success rate of these treatments has been low and a large number of cancers, including colorectal cancer remain largely refractory to CTLA-4 and PD-1 blockade. This has provided impetus to identify other co-inhibitory receptors that could be exploited to enhance response rates of current immunotherapeutic agents and achieve responses to the cancers that are refectory to immunotherapy. Tim-3 is a co-inhibitory receptor that is expressed on IFN-γ-producing T cells, FoxP3+ Treg cells and innate immune cells (macrophages and dendritic cells) where it has been shown to suppress their responses upon interaction with their ligand(s). Tim-3 has gained prominence as a potential candidate for cancer immunotherapy, where it has been shown that in vivo blockade of Tim-3 with other check-point inhibitors enhances anti-tumor immunity and suppresses tumor growth in several preclinical tumor models. This review discusses the recent findings on Tim-3, the role it plays in regulating immune responses in different cell types and the rationale for targeting Tim-3 for effective cancer immunotherapy.

Objectives To determine the accuracy and acceptability to patients of non-endoscopic screening for Barrett's oesophagus, using an ingestible oesophageal sampling device (Cytosponge) coupled with immunocytochemisty for trefoil factor 3. Design Prospective cohort study. Setting 12 UK general practices, with gastroscopies carried out in one hospital endoscopy unit. Participants 504 of 2696 eligible patients (18.7%) aged 50 to 70 years with a previous prescription for an acid suppressant (H 2 receptor antagonist or proton pump inhibitor) for more than three months in the past five years. Main outcome measures Sensitivity and specificity estimates for detecting Barrett's oesophagus compared with gastroscopy as the ideal method, and patient anxiety (short form Spielberger state trait anxiety inventory, impact of events scale) and acceptability (visual analogue scale) of the test. Results 501 of 504 (99%) participants (median age 62, male to female ratio 1:1.2) successfully swallowed the Cytosponge. No serious adverse events occurred. In total, 3.0% (15/501) had an endoscopic diagnosis of Barrett's oesophagus (≥1 cm circumferential length, median circumferential and maximal length of 2 cm and 5 cm, respectively) with intestinal metaplasia. Compared with gastroscopy the sensitivity and specificity of the test was 73.3% (95% confidence interval 44.9% to 92.2%) and 93.8% (91.3% to 95.8%) for 1 cm or more circumferential length and 90.0% (55.5% to 99.7%) and 93.5% (90.9% to 95.5%) for clinically relevant segments of 2 cm or more. Most participants (355/496, 82%, 95% confidence interval 78.9% to 85.1%) reported low levels of anxiety before the test, and scores remained within normal limits at follow-up. Less than 4.5% (2.8% to 6.1%) of participants reported psychological distress a week after the procedure. ConclusionsThe performance of the Cytosponge test was promising and the procedure was well tolerated. These data bring screening for Barrett's oesophagus into the realm of possibility. Further evaluation is recommended.

The cJun N-terminal kinase (JNK) signal transduction pathway is implicated in the regulation of neuronal function. JNK is encoded by three genes that play partially redundant roles. Here we report the creation of mice with targeted ablation of all three Jnk genes in neurons. Compound JNK-deficient neurons are dependent on autophagy for survival. This autophagic response is caused by FoxO-induced expression of Bnip3 that displaces the autophagic effector Beclin-1 from inactive Bcl-XL complexes. These data identify JNK as a potent negative regulator of FoxO-dependent autophagy in neurons.

The cJun NH 2 -terminal kinase (JNK) signal transduction pathway has been implicated in the growth of carcinogen-induced hepatocellular carcinoma. However, the mechanism that accounts for JNK-regulated tumor growth is unclear. Here we demonstrate that compound deficiency of the two ubiquitously expressed JNK isoforms (JNK1 and JNK2) in hepatocytes does not prevent hepatocellular carcinoma development. Indeed, JNK deficiency in hepatocytes increased the tumor burden. In contrast, compound JNK deficiency in hepatocytes and nonparenchymal cells reduced both hepatic inflammation and tumorigenesis. These data indicate that JNK plays a dual role in the development of hepatocellular carcinoma. JNK promotes an inflammatory hepatic environment that supports tumor development, but also functions in hepatocytes to reduce tumor development.

The cJun NH2-terminal kinase (JNK) signaling pathway has been implicated in the development of tumor necrosis factor (TNF) -dependent hepatitis. Indeed, JNK may play a critical role in hepatocytes during TNF-stimulated cell death in vivo. To test this hypothesis, we examined the phenotype of mice with compound disruption of the Jnk1 and Jnk2 genes. Mice with loss of JNK1/2 expression in hepatocytes exhibited no defects in the development of hepatitis compared with control mice. In contrast, mice with loss of JNK1/2 in the hematopoietic compartment exhibited a profound defect in hepatitis that was associated with markedly reduced expression of TNFα. Together, these data indicate that JNK is required for TNFα expression, but JNK is not required for TNFα-stimulated death of hepatocytes. Indeed, TNFα-induced similar hepatic damage in mice with hepatocyte-specific JNK1/2-deficiency and control mice. These observations confirm a role for JNK in the development of hepatitis, but identify hematopoietic cells as the site of the essential function of JNK.

The JNK signaling pathway is implicated in the regulation of the AP1 transcription factor and cell proliferation. Here, we examine the role of JNK by using conditional and chemical genetic alleles of the ubiquitously expressed murine genes that encode the isoforms JNK1 and JNK2. Our analysis demonstrates that JNK is not essential for proliferation. However, JNK is required for expression of the cJun and JunD components of the AP1 transcription factor, and JNK-deficient cells exhibit early p53-dependent senescence. These data demonstrate that JNK can act as a negative regulator of the p53 tumor suppressor.AP1 ͉ cJun ͉ cell cycle I t is established that the JNK signaling pathway is a critical regulator of AP1-dependent gene expression (1). JNK phosphorylation of a number of AP1 and AP1-related transcription factors (e.g., cJun, JunB, JunD, and ATF2) causes increased AP1 transcription activity. In addition, JNK can regulate AP1 activity by increasing the expression of cJun mRNA (by acting at AP1-like sites in the cJun promoter) and regulating the half-life of the cJun protein (1). This role of JNK to increase AP1-dependent gene expression suggests that JNK may play an important role in cellular responses to mitogens (2). Indeed, primary murine fibroblasts (MEF) isolated from compound mutant Jnk1 Ϫ/Ϫ Jnk2 Ϫ/Ϫ embryos proliferate slowly (3). The observation that MEF that lack JNK expression grow slowly suggests that JNK may function to regulate cell-cycle progression. However, the target of JNK signaling that mediates this effect of JNK on proliferation has not been defined. In addition, it is unclear whether the requirement of JNK for proliferation reflects a role for JNK-mediated phosphorylation of a substrate that is critically required for cell-cycle progression or whether it is the prolonged absence of JNK that causes slow growth.To test whether JNK is required for proliferation, we examined the effect of acute loss of JNK function on cellular proliferation. A drug with validated specificity for JNK is not yet available (4). We therefore used genetic approaches to examine the effect of acute loss of JNK function on proliferation. Results and DiscussionConstruction of a Conditional Jnk1 Allele. Mice with a floxed allele of Jnk1 were constructed by using standard techniques (Fig. 1 A-C). These mice were crossed with JNK2-deficient mice to create Jnk1 LoxP/LoxP Jnk2 Ϫ/Ϫ mice. Primary MEF prepared from these animals expressed JNK1. Alternative splicing of Jnk1 mRNA results in the expression of 46-kDa isoforms of JNK1 with a small amount of 54-kDa JNK1 isoforms (5). Cre-mediated excision of the floxed Jnk1 alleles resulted in primary MEF that lack detectable JNK expression (Fig. 1D). We have previously reported that JNK-deficient primary MEF display reduced UV-stimulated apoptosis and increased TNF-stimulated apoptosis (3, 6). The compound knockout MEF derived from conditional JNK mice similarly exhibited reduced UVstimulated apoptosis and increased TNF-stimulated apoptosis [supporting information (SI) Figs. 7 and 8...

The stromal compartment is increasingly recognized to play a role in cancer. However, its role in the transition from preinvasive to invasive disease is unknown. Most gastrointestinal tumors have clearly defined premalignant stages, and Barrett’s esophagus (BE) is an ideal research model. Supervised clustering of gene expression profiles from microdissected stroma identified a gene signature that could distinguish between BE metaplasia, dysplasia, and esophageal adenocarcinoma (EAC). EAC patients overexpressing any of the five genes (TMEPAI, JMY, TSP1, FAPα, and BCL6) identified from this stromal signature had a significantly poorer outcome. Gene ontology analysis identified a strong inflammatory component in BE disease progression, and key pathways included cytokine–cytokine receptor interactions and TGF-β. Increased protein levels of inflammatory-related genes significantly up-regulated in EAC compared with preinvasive stages were confirmed in the stroma of independent samples, and in vitro assays confirmed functional relevance of these genes. Gene set enrichment analysis of external datasets demonstrated that the stromal signature was also relevant in the preinvasive to invasive transition of the stomach, colon, and pancreas. These data implicate inflammatory pathways in the genesis of gastrointestinal tract cancers, which can affect prognosis.