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Leucine-rich repeat-containing G-protein receptor 5 (LGR5) has been characterised as a stem cell and cancer stem cell marker. Previous analyses of LGR5 transcript levels indicate high level expression discriminates malignancies such as colorectal cancer (CRC) and pre-B acute lymphoblastic leukaemia (pre-B ALL) from healthy tissues suggesting LGR5 protein expression may provide a molecular handle for prognosis and treatment.We have developed highly specific, high affinity antibodies to the extracellular domain of human LGR5 (α-LGR5) that detect high LGR5 protein levels in colorectal cancer (CRC), hepatocellular carcinoma (HCC), and pre-B ALL. In contrast, there is low to undetectable levels of LGR5 protein in normal colon and rectal epithelia, liver, ovarian tissues, brain and immune cell types.LGR5 is rapidly internalised from the plasma membrane and trafficked to intracellular vesicular compartments including lysosomes. Treatment of high LGR5-expressing CRC and pre-B ALL cancer cell lines with an antibody-drug conjugate version of α-LGR5 (α-LGR5-ADC) lead to effective cell killing at nanomolar concentrations. Interventional treatment of pre-B ALL tumours with α-LGR5-ADC in vivo led to rapid tumour attrition. We further demonstrated the therapeutic utility of humanised α-LGR5 by using the corresponding scFv fragment for the generation of α-LGR5 chimeric antigen receptors (CARs) and a Bispecific T cell Engager (BiTE). α-LGR5-CAR-NK cells were effective at killing LGR5-expressing cells while α-LGR5/α-CD3 BiTEs induce T cell activation and killing of NALM6 cells by cytotoxic CD8+ T cells.Taken together, this study establishes α-LGR5-based therapeutic modalities that effectively discriminate and target CRC, HCC and pre-B ALL tumour cells.One Sentence SummaryWe generated novel antibodies against the cancer cell marker LGR5, validated diagnostic use in prioritizing specific cancer types for targeting, and developed antibody-based therapeutics.

Metastasis constitutes the primary cause of cancer-related deaths, with the lung being a commonly affected organ. We found that activation of lung-resident group 2 innate lymphoid cells (ILC2s) orchestrated suppression of natural killer (NK) cell-mediated innate antitumor immunity, leading to increased lung metastases and mortality. Using multiple models of lung metastasis, we show that interleukin (IL)-33-dependent ILC2 activation in the lung is involved centrally in promoting tumor burden. ILC2-driven innate type 2 inflammation is accompanied by profound local suppression of interferon-γ production and cytotoxic function of lung NK cells. ILC2-dependent suppression of NK cells is elaborated via an innate regulatory mechanism, which is reliant on IL-5-induced lung eosinophilia, ultimately limiting the metabolic fitness of NK cells. Single-cell and bulk transcriptomic analysis of lung NK cells reveals that post-transcriptional regulation likely accounts for IL-33-ILC2 dependent suppression of NK cell function. Using mass-spectrometry imaging (MSI) of the lungs of 13 C-Glucose infused mice, and metabolite profiling of ex vivo lung cultures, we find that IL-33 drives localized depletion of glucose via ILC2-dependent recruitment of highly glycolytic eosinophils, which can directly suppress lung NK cell function. Therapeutic targeting of IL-33 or IL-5 reversed NK cell suppression and alleviated cancer burden. Thus, we reveal an important function of IL-33 and ILC2s in promoting tumor metastasis via their capacity to suppress innate type 1 immunity.

Summary Senescent cells trigger their own immune-mediated destruction, termed senescence surveillance. This is dependent on the inflammatory senescence-associated secretory phenotype (SASP), which includes COX2, an enzyme with complex roles in cancer. The role COX2 plays during senescence surveillance is unknown. Here, we show that during RAS-induced senescence (RIS), COX2 is a critical regulator of SASP composition and senescence surveillance in vivo. COX2 regulates the expression of multiple inflammatory SASP components through an autocrine feedback loop involving its downstream product, prostaglandin E2 (PGE2), binding to EP4. During in vivo hepatocyte RIS, Cox2 is critical to tumor suppression, Cxcl1 expression, and immune-mediated senescence surveillance, partially through PGE2. Loss of Cox2 in RIS dysregulates the intrahepatic immune microenvironment, with enrichment of immunosuppressive immature myeloid cells and CD4+ regulatory T lymphocytes. Therefore, COX2 and PGE2 play a critical role in senescence, shaping SASP composition, promoting senescence surveillance and tumor suppression in the earliest stages of tumorigenesis., Graphical abstract, Highlights • COX2 is upregulated in senescence and controls expression of multiple SASP components • COX2 regulates SASP composition partly via autocrine feedback involving PGE2 and EP4 • In hepatocyte senescence, Cox2 promotes senescence surveillance and tumor suppression • Cox2 regulates the immune microenvironment of the liver, partly through PGE2, Gonçalves et al. identify COX2 as a regulator of senescence secretome composition through an autocrine feedback loop involving PGE2 and EP4. During hepatocyte senescence, Cox2 is critical to tumor suppression, Cxcl1 expression, the immune microenvironment, and immune-mediated senescence surveillance, partially through PGE2.

This article presents current magnetic resonance imaging techniques for the diagnosis of biliary tumors. It emphasizes the need for a comprehensive protocol, combining imaging sequences of the liver parenchyma and soft tissues with magnetic resonance cholangiopancreatography and magnetic resonance angiography to detect and stage biliary malignancies. Imaging characteristics that may indicate a specific diagnosis are discussed. The potential role of diffusion-weighted imaging in diagnosing the cause of biliary obstruction and detecting unsuspected nodal disease and peritoneal seeding is emphasized and illustrated.

To assess the potential of a gene reporter system, based on a urea transporter (UTB) and hyperpolarized [(13) C]urea.Mice were implanted subcutaneously with either unmodified control cells or otherwise identical cells expressing UTB. After injection of hyperpolarized [(13) C]urea, a spin echo sequence was used to measure urea concentration, T1 , and diffusion in control and UTB-expressing tissue.The apparent diffusion coefficient of hyperpolarized urea was 21% lower in tissue expressing UTB, in comparison with control tissue (P 0.05, 1-tailed t-test, n = 6 in each group). No difference in water apparent diffusion coefficient or cellularity between these tissues was found, indicating that they were otherwise similar in composition.Expression of UTB, by mediating cell uptake of urea, lowers the apparent diffusion coefficient of hyperpolarized (13) C urea in tissue and thus the transporter has the potential to be used as a magnetic resonance-based gene reporter in vivo. Magn Reson Med 73:1401-1406, 2015. © 2014 Wiley Periodicals, Inc.

Congenital esophageal stenosis (CES) is a rare anomaly, resulting from incomplete separation of the respiratory tract from the primitive foregut at the 25th day of life. First clinical signs are abnormalities of the swallowing mechanism caused by the intrinsic narrowing of the esophagus. Diagnosis is usually delayed, requiring an accurate history and high level of suspicion, alongside with an esophagogram. Definite diagnosis is only confirmed by histological examination. Treatment usually involves surgery, depending on the severity, location and type of stenosis. We report the case of an 18 months old toddler diagnosed with CES. The characteristic radiographic and CT features are presented as well as the histology.