Furospinosulin-1, Marine Spongean Furanosesterterpene, Suppresses the Growth of Hypoxia-Adapted Cancer Cells by Binding to Transcriptional Regulators p54(nrb) and LEDGF/p75.

Hypoxia-adapted cancer cells in tumors contribute to the pathological progression of cancer. Cancer research has therefore focused on the identification of molecules responsible for hypoxia adaptation in cancer cells, as well as the development of new compounds with action against hypoxia-adapted cancer cells. The marine natural product furospinosulin-1 (1) has displayed hypoxia-selective growth inhibition against cultured cancer cells, and has shown in vivo anti-tumor activity, although its precise mode of action and molecular targets remain unclear. In this study, we found that 1 is selectively effective against hypoxic regions of tumors, and that it directly binds to the transcriptional regulators p54(nrb) and LEDGF/p75, which have not been previously identified as mediators of hypoxia adaptation in cancer cells.

Synthesis and evaluation of effective photoaffinity probe molecule of furospinosulin-1, a hypoxia-selective growth inhibitor.

The synthesis and evaluation of a photoaffinity probe molecule for furospinosulin-1, a hypoxia-selective growth inhibitor that we identified from marine sponge, was studied. An analogue carrying an alkyne tail showed potent hypoxia-selective inhibitory activity exceeding that of the parent molecule, and exhibited in vivo anti-tumor activity following oral administration. The alkyne moiety in the analogue was also found to be a good anchoring group for the preparation of probe molecules; a photoaffinity probe molecule having an optimized spacer length was selected through the systematic synthesis of several probes and the evaluation of their hypoxia-selective growth inhibitory activity and electrophoretic mobility shift properties.

Extracellular matrix lumican promotes bacterial phagocytosis, and Lum-/- mice show increased Pseudomonas aeruginosa lung infection severity.

Phagocytosis is central to bacterial clearance, but the exact mechanism is incompletely understood. Here, we show a novel and critical role for lumican, the connective tissue extracellular matrix small leucine-rich repeat proteoglycan, in CD14-mediated bacterial phagocytosis. In Psuedomonas aeruginosa lung infections, lumican-deficient (Lum(-/-)) mice failed to clear the bacterium from lungs, tissues, and showed a dramatic increase in mortality. In vitro, phagocytosis of nonopsonized gram-negative Escherichia coli and P. aeruginosa was inhibited in Lum(-/-) peritoneal macrophages (MΦs). Lumican co-localized with CD14, CD18, and bacteria on Lum(+/+) MΦ surfaces. Using two different P. aeruginosa strains that require host CD14 (808) or CD18/CR3 (P1) for phagocytosis, we showed that lumican has a larger role in CD14-mediated phagocytosis. Recombinant lumican (rLum) restored phagocytosis in Lum(-/-) MΦs. Surface plasmon resonance showed specific binding of rLum to CD14 (K(A) = 2.15 × 10(6) M(-1)), whereas rLumY20A, and not rLumY21A, where a tyrosine in each was replaced with an alanine, showed 60-fold decreased binding. The rLumY20A variant also failed to restore phagocytosis in Lum(-/-) MΦs, indicating Tyr-20 to be functionally important. Thus, in addition to a structural role in connective tissues, lumican has a major protective role in gram-negative bacterial infections, a novel function for small leucine-rich repeat proteoglycans.

Inhibition of Fas ligand in NOD mice unmasks a protective role for IL-10 against insulitis development.

Type 1 diabetes mellitus (T1D) is an autoimmune disease caused by the destruction of pancreatic insulin-producing ß cells by autoreactive T cells early in life. Despite daily insulin injections, patients typically develop cardiovascular and other complications; and intensive efforts are being directed toward identifying therapeutic targets to prevent the disease without directly impinging on the host defense. Fas ligand (FasL) is one potential target. Fas-FasL interactions primarily regulate T-cell homeostasis, not activation. Nevertheless, spontaneous gene mutation of Fas (called lpr mutation) or FasL (called the gld mutation) prevents autoimmune diabetes in nonobese diabetic (NOD) mice, the widely used model for T1D. Furthermore, although homozygous gld mutations cause age-dependent lymphoproliferation, limiting the gld mutation to one allele (NOD-gld/+) or treating NOD-wild-type mice with FasL-neutralizing monoclonal antibody completely prevents the disease development without causing lymphoproliferation or immune suppression. Herein, we show that the heterozygous gld mutation inhibits the accumulation of diabetogenic T cells in the pancreas, without interfering with their proliferation and expansion in the draining pancreatic lymph nodes. Pancreata from NOD-gld/+ mice contained B cells that expressed CD5 and produced IL-10, which was critical for maintenance of the disease resistance because its neutralization with an IL-10 receptor-blocking monoclonal antibody allowed accumulation of CD4 T cells in the pancreas and led to insulitis development. The results provide novel insights into the pathogenesis of T1D that could have important therapeutic implications.

Upper Endoscopy up to 3 Years Prior to a Diagnosis of Gastric Cancer Is Associated With Lower Stage of Disease in a USA Multiethnic Urban Population, a Retrospective Study.

OBJECTIVES: In the USA, certain races and ethnicities have a disproportionately higher gastric cancer burden. Selective screening might allow for earlier detection and curative resection. Among a USA-based multiracial and ethnic cohort diagnosed with non-cardia gastric cancer (NCGC), we aimed to identify factors associated with curable stage disease at diagnosis. METHODS: We retrospectively identified endoscopically diagnosed and histologically confirmed cases of NCGC at Mount Sinai Hospital in New York City. Demographic, clinical, endoscopic and histologic factors, as well as grade/stage of NCGC at diagnosis were documented. The primary outcome was the frequency of curable-stage NCGC (stage 0-1a) at diagnosis in patients with versus without an endoscopy negative for malignancy prior to their index exam diagnosing NCGC. Additional factors associated with curable-stage disease at diagnosis were determined. RESULTS: A total of 103 racially and ethnically diverse patients were included. Nearly 38% of NCGC were stage 0-Ia, 34% stage Ib-III, and 20.3% stage IV at diagnosis. A significantly higher frequency of NCGC was diagnosed in curable stages among patients who had undergone an endoscopy that was negative for malignancy prior to their index endoscopy that diagnosed NCGC, compared to patients without a negative endoscopy prior to their index exam (69.6% vs. 28.6%, p=0.003). A prior negative endoscopy was associated with 94.0% higher likelihood of diagnosing curable-stage NCGC (p=0.003). No other factors analyzed were associated with curable-stage NCGC at diagnosis. CONCLUSIONS: Endoscopic screening and surveillance in select high-risk populations might increase diagnoses of curable-stage NCGC. These findings warrant confirmation in larger, prospective studies.

Chronic caloric restriction induces forestomach hypertrophy with enhanced ghrelin levels during aging.

Caloric restriction (CR) is the only preventive intervention that has robust pro-longevity effects in experimental models. Various circulating hormones that regulate the state of negative energy balance may drive the multi-system beneficial effects of the CR phenomenon. Ghrelin, one such stomach-derived circulating peptide hormone stimulates food intake, promotes GH release and inhibits pro-inflammatory cytokines. We have recently demonstrated that ghrelin also reverses age-related thymic involution. Here, we report that chronic CR in aging mice results in reduction in body weight, and spleen size but remarkably, leads to a significant increase in the size and weight of stomach. The increased size of stomach was largely due to increased size of fundus (forestomach) and also smaller but statistically significant enlargement of antrum. The analysis of serial stomach sections revealed that chronic CR leads to a striking hypertrophy of lamina propria, stratum basale, stratum corneum and the stratified squamous epithelium of forestomach of the aged animals. We also report for the first time that chronic CR during aging significantly increases circulating ghrelin levels as well as total ghrelin production in the stomach and reverses age-related loss of ghrelin receptor expression in pituitary. Our data suggests that long-term CR-induced increased ghrelin production from hypertrophic stomach in mice may be an adaptive survival strategy in response to sustained negative energy balance that triggers heightened state of food seeking. Taken together, these data provide new insights into the underlying mechanism behind the salutary effects of chronic caloric restriction during aging process.

Extracellular matrix protein lumican promotes clearance and resolution of Pseudomonas aeruginosa keratitis in a mouse model.

Lumican is an extracellular protein that associates with CD14 on the surface of macrophages and neutrophils, and promotes CD14-TLR4 mediated response to bacterial lipopolysaccharides (LPS). Lumican-deficient (Lum(-/-)) mice and macrophages are impaired in TLR4 signals; raising the possibility that lumican may regulate host response to live bacterial infections. In a recent study we showed that invitro Lum(-/-) macrophages are impaired in phagocytosis of gram-negative bacteria and in a lung infection model the Lum(-/-) mice showed poor survival. The cornea is an immune privileged barrier tissue that relies primarily on innate immunity to protect against ocular infections. Lumican is a major component of the cornea, yet its role in counteracting live bacteria in the cornea remains poorly understood. Here we investigated Pseudomonas aeruginosa infections of the cornea in Lum(-/-) mice. By flow cytometry we found that 24 hours after infection macrophage and neutrophil counts were lower in the cornea of Lum(-/-) mice compared to wild types. Infected Lum(-/-) corneas showed lower levels of the leukocyte chemoattractant CXCL1 by 24-48 hours of infection, and increased bacterial counts up to 5 days after infection, compared to Lum(+/-) mice. The pro-inflammatory cytokine TNF-α was comparably low 24 hours after infection, but significantly higher in the Lum(-/-) compared to Lum(+/-) infected corneas by 2-5 days after infection. Taken together, the results indicate that lumican facilitates development of an innate immune response at the earlier stages of infection and lumican deficiency leads to poor bacterial clearance and resolution of corneal inflammation at a later stage.