Evaluation of TAK-264, an Antibody-Drug Conjugate in Pancreatic Cancer Cell Lines and Patient-Derived Xenograft Models.

BACKGROUND: Antibody-drug conjugates (ADCs) are an emerging technology consisting of an antibody, linker, and toxic agent, which have the potential to offer a targeted therapeutic approach. A novel target recently explored for the treatment of pancreatic cancer is guanylyl cyclase C (GCC). The objective of this study was to determine the anti-tumorigenic activity of TAK-264, an investigational ADC consisting of an antibody targeting GCC linked to a monomethyl auristatin E payload via a peptide linker. METHODS: The antiproliferative effects of TAK-264 assessed in a panel of eleven pancreatic cancer cell lines. Additionally, ten unique pancreatic ductal adenocarcinoma cancer patient-derived xenograft models were treated with TAK-264 and the efficacy was determined. Baseline levels of GCC were analyzed on PDX models and cell lines. Immunoblotting was performed to evaluate the effects of TAK-264 on downstream effectors. RESULTS: GCC protein expression was analyzed by immunoblotting in both normal and tumor tissue; marked increase in GCC expression was observed in tumor tissue. The in vitro experiments demonstrated a range of responses to TAK-264. Eight of the ten PDAC PDX models treated with TAK-264 demonstrated a statistically significant tumor growth inhibition. Immunoblotting demonstrated an increase in phosphorylated-HistoneH3 in both responsive and less responsive cell lines and PDAC PDX models treated with TAK-264. There was no correlation between baseline levels of GCC and response in either PDX or cell line models. CONCLUSION: TAK-264 has shown suppression activity in pancreatic cancer cell lines and in pancreatic PDX models. These findings support further investigation of ADC targeting GCC.

First-Trimester Vaginal Bleeding: Patient Expectations When Presenting to the Emergency Department.

OBJECTIVE: First-trimester vaginal bleeding is a common presenting complaint to the emergency department (ED). Many studies have looked at risk factors, evaluation, and treatment, but none have looked at the motivating factors for seeking care. The objective was to identify the most commonly held concerns by women experiencing first-trimester vaginal bleeding. METHODS: A questionnaire was distributed to pregnant patients as they checked into the ED from January to July of 2013 with concern for first-trimester vaginal bleeding. Patients were instructed to rank a prepopulated list of reasons motivating their visit on the basis of level of importance. The study was given expedited approval by the Office of the Institutional Review Board. RESULTS: The most common reason behind a visit for vaginal bleeding in the first trimester was to have an ultrasound and blood work performed to evaluate the well-being of their fetus (41.8% [95% confidence interval (CI) 34-50.1%]). The second most common reason, with a rate of 34% (CI 26.7-42.2%), was to simply know whether or not the patient was having a miscarriage, with no specific method of evaluation mentioned. A minority of patients ranked the potentially emergent conditions such as ectopic (3.5%), life-threatening hemorrhage (4.3%), or otherwise abnormal pregnancy (2.1%) as being their chief concern. CONCLUSIONS: First-trimester vaginal bleeding is a commonly encountered complaint in ED. Results obtained in this study reveal the largest proportion of patients surveyed expected an ultrasound and blood work and wanted to know by the end of the visit if she was having a miscarriage. This information gained from this study may be helpful to the emergency physician in managing expectations, catering to the patient's concerns, and may also be useful in boosting patient satisfaction.

Rapid decline in lung function in healthy adults predicts incident excess urinary albumin excretion later in life.

INTRODUCTION: Chronic lung disease, often characterised by rapid decline in lung function, is associated with vascular endothelial dysfunction (characterised by moderate to severe excess urinary albumin excretion (eUAE) but their longitudinal relationship is inadequately studied. In a bidirectional longitudinal examination of healthy adults, we analysed the following two hypotheses: (1) rapid decline (ie, highest tertile of lung function decline) predicts eUAE and (2) eUAE predicts rapid decline. METHODS: We performed a secondary data analysis from 3052 eligible participants from the Coronary Artery Risk Development in Young Adults (CARDIA) study. For analysis 1, the predictor was rapid decline in lung function between the peak value (attained at or before CARDIA visit year 10 or Y10 at a mean age of 35 years) and Y20; and the outcome was incident eUAE at Y20 and/or Y25. For analysis 2, the predictor was eUAE at Y10 and the outcome was rapid decline between Y10 and Y20. RESULTS: After adjustment for covariates in analysis 1, rapid decline in FEV1 or FVC between peak and Y20 predicted incident eUAE at Y20 and/or Y25 (OR 1.51 and 1.44, respectively; p≤0.05 for both analyses). In analysis 2, eUAE at Y10 did not predict subsequent rapid decline. CONCLUSIONS: Healthy adults with rapid decline in lung function are at risk for developing vascular endothelial dysfunction, as assessed by incident eUAE, later in life.

A novel role for tumor necrosis factor-like weak inducer of apoptosis (TWEAK) in the development of cardiac dysfunction and failure.

BACKGROUND: Tumor necrosis factor-like weak inducer of apoptosis (TWEAK), a member of the tumor necrosis factor superfamily, is a multifunctional cytokine known to regulate cellular functions in contexts of injury and disease through its receptor, fibroblast growth factor-inducible molecule 14 (Fn14). Although many of the processes and downstream signals regulated by the TWEAK/Fn14 pathway have been implicated in the development of cardiac dysfunction, the role of TWEAK in the cardiovascular system is completely unknown. METHODS AND RESULTS: Herein, we demonstrate that mouse and human cardiomyocytes express the TWEAK receptor Fn14. Furthermore, we determine that elevated circulating levels of TWEAK, induced via transgenic or adenoviral-mediated gene expression in mice, result in dilated cardiomyopathy with subsequent severe cardiac dysfunction. This phenotype was mediated exclusively by the Fn14 receptor, independent of tumor necrosis factor-alpha, and was associated with cardiomyocyte elongation and cardiac fibrosis but not cardiomyocyte apoptosis. Moreover, we find that circulating TWEAK levels were differentially upregulated in patients with idiopathic dilated cardiomyopathy compared with other forms of heart disease and normal control subjects. CONCLUSIONS: Our data suggest that TWEAK/Fn14 may be important in regulating myocardial structural remodeling and function and may play a role in the pathogenesis of dilated cardiomyopathy.

The plant pathogenesis related protein GLIPR-2 is highly expressed in fibrotic kidney and promotes epithelial to mesenchymal transition in vitro.

Fibrosis is the accumulation of extracellular matrix proteins and is a common end pathway in many chronic diseases. To identify novel mediators of fibrosis we used transcript profiling in a mouse model of kidney fibrosis, the COL4A3 knockout (alport) mouse. One gene that we found up-regulated in fibrotic kidney was GLIPR-2, also known as GAPR-1 and C9orf19, a member of the plant pathogenesis-related proteins family 1. We have found that GLIPR-2 protein expression is significantly increased in fibrotic kidney compared to healthy controls. Examination of the expression pattern of GLIPR-2 indicated that the protein is selectively expressed in epithelial cells. Co-staining with antibodies for alpha-smooth muscle actin expression, a marker of myofibroblasts, showed that GLIPR-2 expressing cells are closely apposed to areas of strong alpha-smooth muscle actin expression. The origin of these myofibroblasts is not known, but in vitro studies have shown that GLIPR-2 can induce epithelial to mesenchymal transition (EMT) in a renal epithelial cell line. We propose that increased GLIPR-2 expression in kidney contributes to development of fibrosis by increasing the pool of activated fibroblasts, possibly through the induction of EMT.

Targeting the lymphotoxin-beta receptor with agonist antibodies as a potential cancer therapy.

The lymphotoxin-beta receptor (LT beta R) is a tumor necrosis factor receptor family member critical for the development and maintenance of various lymphoid microenvironments. Herein, we show that agonistic anti-LT beta R monoclonal antibody (mAb) CBE11 inhibited tumor growth in xenograft models and potentiated tumor responses to chemotherapeutic agents. In a syngeneic colon carcinoma tumor model, treatment of the tumor-bearing mice with an agonistic antibody against murine LT beta R caused increased lymphocyte infiltration and necrosis of the tumor. A pattern of differential gene expression predictive of cellular and xenograft response to LT beta R activation was identified in a panel of colon carcinoma cell lines and when applied to a panel of clinical colorectal tumor samples indicated 35% likelihood a tumor response to CBE11. Consistent with this estimate, CBE11 decreased tumor size and/or improved long-term animal survival with two of six independent orthotopic xenografts prepared from surgical colorectal carcinoma samples. Targeting of LT beta R with agonistic mAbs offers a novel approach to the treatment of colorectal and potentially other types of cancers.

TWEAK is a novel arthritogenic mediator.

TNF-like weak inducer of apoptosis (TWEAK) is a TNF family member with pleiotropic effects on a variety of cell types, one of which is the induction of proinflammatory cytokines by synovial fibroblasts derived from rheumatoid arthritis (RA) patients. In this study, we report that the serum TWEAK level was dramatically elevated during mouse collagen-induced arthritis (CIA) and blocking TWEAK by a neutralizing mAb significantly reduced the clinical severity of CIA. Histological analyses also revealed that TWEAK inhibition diminished joint inflammation, synovial angiogenesis, as well as cartilage and bone erosion. Anti-TWEAK treatment proved efficacious when administered just before the disease onset but not during the priming phase of CIA. Consistent with this, TWEAK inhibition did not affect either cellular or humoral responses to collagen. In contrast, TWEAK inhibition significantly reduced serum levels of a panel of arthritogenic mediators, including chemokines such as MIP-1beta (CCL-4), lymphotactin (XCL-1), IFN-gamma-inducible protein 10 (IP-10) (CXCL-10), MCP-1 (CCL-2), and RANTES (CCL-5), as well as the matrix metalloprotease-9. Exploring the possible role of the TWEAK/Fn14 pathway in human RA pathogenesis, we showed that TWEAK can target human primary chondrocytes and osteoblast-like cells, in addition to synovial fibroblasts. We further demonstrated that TWEAK induced the production of matrix metalloproteases in human chondrocytes and potently inhibited chondrogenesis and osteogenesis using in vitro models. These results provide evidence for a novel cytokine pathway that contributes to joint tissue inflammation, angiogenesis, and damage, as well as may inhibit endogenous repair, suggesting that TWEAK may be a new therapeutic target for human RA.

Analysis of the tight skin (Tsk1/+) mouse as a model for testing antifibrotic agents.

The tight skin 1 (B6.CgFbn1(Tsk)+/+Pldn(pa)/J, henceforth referred to as Tsk1/+) mouse was first described as a spontaneously occurring mutant that resulted in hyperplasia of the subcutaneous loose connective tissue, and has subsequently been proposed to be a model of the human fibrotic disorder scleroderma. We have investigated the Tsk1/+ mouse as a model system for testing the efficacy of antifibrotic agents against skin fibrosis. We find that the tightness of the skin at the scruff of the neck leads to a measurably thicker skin pinch, but we suggest that this is due to hyperplasia of the subdermal loose connective tissue, which results in increased tethering of the skin to the underlying muscle layers. In contrast to previously published data, we do not find a significant difference in the dermal thickness or collagen content of the Tsk1/+ mouse skin compared with wild-type controls. In addition, expression profiling of Tsk1/+ mouse skin indicated that there are very few changes in gene expression, and that there is no evidence for upregulation of the transforming growth factor beta signaling axis. Therefore, we conclude that this model is not suitable for testing the effect of antifibrotic agents on the dermis, and that changes potentially related to scleroderma may be confined to subdermal connective tissue.

Murine peptidoglycan recognition proteins PglyrpIalpha and PglyrpIbeta are encoded in the epidermal differentiation complex and are expressed in epidermal and hematopoietic tissues.

Peptidoglycan recognition proteins (PGRPs or PGLYRPs) are pattern recognition molecules that are found in insects and mammals and are critical for innate immune responses. PGRPs bind peptidoglycan, a ubiquitous component of bacterial cell walls, and are involved in killing bacteria, degrading peptidoglycan, and initiating host defense reactions. Relatively little is known about the four mammalian PGRPs. In this article, we report the sequences of mouse PglyrpIalpha and PglyrpIbeta and provide details of their expression in wild-type mouse tissues. PglyrpIalpha and PglyrpIbeta are encoded within the epidermal differentiation complex on mouse chromosome 3F. Both genes are expressed in epidermal and hematopoietic tissues. PglyrpIbeta is expressed in each of 16 tissues tested, while PglyrpIalpha expression is limited to fewer tissues, including the lung and spleen as well as several tissues of the digestive system. Both proteins are expressed in epithelial cells throughout the gut, and immunohistochemical staining shows expression in salivary glands, the squamous epithelium of the stomach, and the villi of the jejunum. Immunohistochemical staining further shows expression of both PglyrpIalpha and PglyrpIbeta in macrophages in the spleen. PglyrpIalpha is not expressed in resting RAW264.7 macrophage-like cells, but is induced by stimulation with lipopolysaccharide. PglyrpIbeta is constitutively expressed in RAW264.7 cells and is unaffected by lipopolysaccharide or peptidoglycan stimulation. Computational and experimental data suggest that these proteins are secreted. This work provides a step toward understanding the roles of PglyrpIalpha and PglyrpIbeta in host defense and chronic inflammatory conditions induced by bacteria or their components.

LINGO-1 is a component of the Nogo-66 receptor/p75 signaling complex.

Axon regeneration in the adult CNS is prevented by inhibitors in myelin. These inhibitors seem to modulate RhoA activity by binding to a receptor complex comprising a ligand-binding subunit (the Nogo-66 receptor NgR1) and a signal transducing subunit (the neurotrophin receptor p75). However, in reconstituted non-neuronal systems, NgR1 and p75 together are unable to activate RhoA, suggesting that additional components of the receptor may exist. Here we describe LINGO-1, a nervous system-specific transmembrane protein that binds NgR1 and p75 and that is an additional functional component of the NgR1/p75 signaling complex. In non-neuronal cells, coexpression of human NgR1, p75 and LINGO-1 conferred responsiveness to oligodendrocyte myelin glycoprotein, as measured by RhoA activation. A dominant-negative human LINGO-1 construct attenuated myelin inhibition in transfected primary neuronal cultures. This effect on neurons was mimicked using an exogenously added human LINGO-1-Fc fusion protein. Together these observations suggest that LINGO-1 has an important role in CNS biology.

Kirrel2, a novel immunoglobulin superfamily gene expressed primarily in beta cells of the pancreatic islets.

A novel immunoglobulin superfamily (Igsf) protein gene was discovered by computational analysis of human draft genomic DNA, and multiple cDNA clones were obtained. The protein encoded by this gene contains five Ig domains, one transmembrane domain, and an intracellular domain. It has significant similarity with several known Igsf proteins, including Drosophila RST (irregular chiasm C-roughest) protein and mammalian KIRREL (kin of irregular chiasm C-roughest), NEPH1, and NPHS1 (nephrin) proteins. All these proteins have multiple Ig domains, possess properties of cell adhesion molecules, and play important roles in organ development. RT-PCR and Northern blot results indicate this gene is predominantly expressed in pancreas, and public sequence databases indicate there is also expression in the nervous system. We have named this gene Kirrel2 (kin of irregular chiasm-like 2), to reflect its similarity to irregular chiasm C-roughest and Kirrel. Four splice forms of Kirrel2 were observed, including two that we cloned from pancreas mRNA as well as two GenBank entries, one from the brain and one from a retinoblastoma cell line. A partial cDNA clone of the mouse orthologue was obtained by RT-PCR from mouse brain, and the inferred protein sequence has 85% sequence identity to the human protein. Immunohistochemical staining results indicate that the KIRREL2 protein is conserved from rodents to primates, and it is highly expressed in pancreatic islets. RT-PCR results on mouse pancreatic cell lines indicate that expression in the pancreas is restricted to beta cells. Thus, KIRREL2 protein is a beta-cell-expressed Ig domain protein and may be involved in pancreas development or beta cell function.

Disruption of hedgehog signaling reveals a novel role in intestinal morphogenesis and intestinal-specific lipid metabolism in mice.

BACKGROUND & AIMS: The hedgehog (hh) signaling pathway has been shown to play crucial roles in the development of embryonic gut. However, its role in intestinal development and function beyond the embryonic stage is still undefined. METHODS: Expression of hh and its receptor, Patched, were examined by Western blot and X-gal staining. An anti-hh monoclonal antibody was administered into developing embryos or postnatal mice and histologic analyses were performed. Effects on lipid metabolism were examined by Oil Red O and Sudan III stainings, messenger RNA (mRNA) analysis, and electron microscopy. Serum apolipoprotein IV level, a marker for lipid absorption, was quantified by Western blot. RESULTS: Mice receiving anti-hh monoclonal antibody in utero or after birth exhibited progressive runting and died before weaning. Histology revealed hyperproliferation of intestinal crypt epithelial cells and disorganization of the villi with prominent vacuolation and accumulation of neutral lipid. Fecal fat microscopy revealed numerous large fat droplets. Intestinal mRNA abundance of 2 candidate genes involved in lipid transport, mtp and apob, was unchanged, although serum levels of apolipoprotein A-IV were reduced. CONCLUSIONS: Abnormal villus structure, lipid-filled enterocytes, and fatty stools in anti-hh monoclonal antibody-treated mice indicate a novel role for hh signaling in intestinal morphogenesis and lipid transport in postnatal mice.