A synthetic modular approach for modeling the role of the 3D microenvironment in tumor progression

Here, we demonstrate the flexibility of peptide-functionalized poly(ethylene glycol) (PEG) hydrogels for modeling tumor progression. The PEG hydrogels were formed using thiol-ene chemistry to incorporate a matrix metalloproteinase-degradable peptide crosslinker (KKCGGPQG↓IWGQGCKK) permissive to proteolytic remodeling and the adhesive CRGDS peptide ligand. Tumor cell function was investigated by culturing WM239A melanoma cells on PEG hydrogel surfaces or encapsulating cells within the hydrogels, and either as monocultures or indirect (non-contact) cocultures with primary human dermal fibroblasts (hDFs). WM239A cluster size and proliferation rate depended on the shear elastic modulus for cells cultured on PEG hydrogels, while growth was inhibited by coculture with hDFs regardless of hydrogel stiffness. Cluster size was also suppressed by hDFs for WM239A cells encapsulated in PEG hydrogels, which is consistent with cells seeded on top of hydrogels. Notably, encapsulated WM239A clusters and single cells adopted invasive phenotypes in the hDF coculture model, which included single cell and collective migration modes that resembled invasion from human melanoma patient-derived xenograft tumors encapsulated in equivalent PEG hydrogels. Our combined results demonstrate that peptide-functionalized PEG hydrogels provide a useful platform for investigating aspects of tumor progression in 2D and 3D microenvironments, including single cell migration, cluster growth and invasion.

Observation of Spin-Dependent Charge Symmetry Breaking in ΛN Interaction: Gamma-Ray Spectroscopy of _{Λ}^{4}He

The energy spacing between the spin-doublet bound state of _{Λ}^{4}He(1^{+},0^{+}) was determined to be 1406±2±2  keV, by measuring γ rays for the 1^{+}→0^{+} transition with a high efficiency germanium detector array in coincidence with the ^{4}He(K^{-},π^{-})_{Λ}^{4}He reaction at J-PARC. In comparison to the corresponding energy spacing in the mirror hypernucleus _{Λ}^{4}H, the present result clearly indicates the existence of charge symmetry breaking (CSB) in ΛN interaction. By combining the energy spacings with the known ground-state binding energies, it is also found that the CSB effect is large in the 0^{+} ground state but is vanishingly small in the 1^{+} excited state, demonstrating that the ΛN CSB interaction has spin dependence.

Overall Survival Is Impacted by Birthplace and Not Extent of Surgery in Asian Americans with Resectable Gastric Cancer

Survival from gastric cancer in the USA still lags behind Asia. Genetic, environmental, and tumor biology differences, along with extent of surgery have been implicated. Our aim was to evaluate survival outcomes in Asian-American gastric cancer patients undergoing surgical resection by comparing place of birth and clinicopathologic characteristics (including evaluation of 15 lymph nodes).The Surveillance, Epidemiology, and End Results database was queried to identify patients treated surgically for gastric cancer with curative intent in the USA (2000-2010). US-born versus foreign-born Asian-American patients were analyzed for survival. Secondary comparison was made to non-Asian patients. Stage IV and non-surgical patients were excluded. Of 10,089 patients identified, 1467 patients were Asian: 271 were born in the USA, and 1196 were born outside the USA. Median survival was 32 months for non-Asians and 29 months for US-born Asians versus 61 months for Asian immigrants (p < 0.001). On multivariable analysis of overall survival in Asian patients, only US birthplace, older age, and higher stage yielded a significantly poorer outcome. Asian-American patients have a worse prognosis if born in the USA. Anatomic and surgical differences do not explain this disparity; environmental factors may be responsible.

Effects of ONO-6950, a novel dual cysteinyl leukotriene 1 and 2 receptors antagonist, in a guinea pig model of asthma

We assessed in this study the anti-asthmatic effects of ONO-6950, a novel cysteinyl leukotriene 1 (CysLT1) and 2 (CysLT2) receptors dual antagonist, in normal and S-hexyl glutathione (S-hexyl GSH)-treated guinea pigs, and compared these effects to those of montelukast, a CysLT1 selective receptor antagonist. Treatment with S-hexyl GSH reduced animals LTC4 metabolism, allowing practical evaluation of CysLT2 receptor-mediated airway response. ONO-6950 antagonized intracellular calcium signaling via human and guinea pig CysLT1 and CysLT2 receptors with IC50 values of 1.7 and 25 nM, respectively (human receptors) and 6.3 and 8.2 nM, respectively (guinea pig receptors). In normal guinea pigs, both ONO-6950 (1 or 0.3 mg/kg, p.o.) and the CysLT1 receptor antagonist montelukast (0.3 or 0.1 mg/kg, p.o.) fully attenuated CysLT1-mediated bronchoconstriction and airway vascular hyperpermeability induced by LTD4. On the other hand, in S-hexyl GSH-treated guinea pigs ONO-6950 at 3 mg/kg, p.o. or more almost completely inhibited bronchoconstriction and airway vascular hyperpermeability elicited by LTC4, while montelukast showed only partial or negligible inhibition of these airway responses. In ovalbumin sensitized guinea pigs, treatment with S-hexyl GSH on top of pyrilamine and indomethacin rendered antigen-induced bronchoconstriction sensitive to both CysLT1 and CysLT2 receptor antagonists. ONO-6950 strongly inhibited this asthmatic response to the level attained by combination therapy with montelukast and BayCysLT2RA, a selective CysLT2 receptor antagonist. These results clearly demonstrate that ONO-6950 is an orally active dual CysLT1/LT2 receptor antagonist that may provide a novel therapeutic option for patients with asthma.

Discovery of Gemilukast (ONO-6950), a Dual CysLT1 and CysLT2 Antagonist As a Therapeutic Agent for Asthma

An orally active dual CysLT1 and CysLT2 antagonist possessing a distinctive structure which consists of triple bond and dicarboxylic acid moieties is described. Gemilukast (ONO-6950) was generated via isomerization of the core indole and the incorporation of a triple bond into a lead compound. Gemilukast exhibited antagonist activities with IC50 values of 1.7 and 25 nM against human CysLT1 and human CysLT2, respectively, and potent efficacy at an oral dose of 0.1 mg/kg given 24 h before LTD4 challenge in a CysLT1-dependent guinea pig asthmatic model. In addition, gemilukast dose-dependently reduced LTC4-induced bronchoconstriction in both CysLT1- and CysLT2-dependent guinea pig asthmatic models, and it reduced antigen-induced constriction of isolated human bronchi. Gemilukast is currently being evaluated in phase II trials for the treatment of asthma.

A novel method for assessing bladder-related pain reveals the involvement of nerve growth factor in pain associated with cyclophosphamide-induced chronic cystitis in mice

BACKGROUND

Pain is a prominent feature of interstitial cystitis/painful bladder syndrome (IC/PBS), but the underlying mechanisms are not fully understood. There is a lack of well-characterized research tools, such as pain evaluation methods and experimental animal models, for investigating non-ulcerative cystitis. We developed a novel method for evaluating bladder pain in mice with cyclophosphamide (CYP)-induced cystitis.

METHODS

Cystitis was produced by a single intraperitoneal injection of CYP (300 mg/kg) or repeated injections of CYP (150 mg/kg once daily for 4 days). Blunt stimulation with a cotton probe was applied to the abdominal region, and the thresholds for withdrawal responses were measured quantitatively using an anaesthesiometer.

RESULTS

The single injection of CYP provoked acute cystitis with severe bladder inflammation in mice. In these mice, we could detect an increased sensitivity to blunt stimulation, which was abolished by intravesical lidocaine. The stimulation induced phosphorylation of extracellular signal-regulated kinases in bladder-projecting sensory neurons. Chronic treatment with CYP produced persistent pain responses to the blunt stimulus. Although there were few signs of bladder inflammation in these mice, the concentration of nerve growth factor (NGF) was elevated in bladder tissue, and NGF antiserum inhibited the hypersensitivity.

CONCLUSIONS

The blunt probe method is useful for evaluating bladder pain signalling in mice, and revealed the involvement of an NGF-sensitive pain pathway in chronic cystitis pain. This assessment method may be useful for studying the pathophysiology of bladder pain and for developing therapeutic strategies for non-ulcerative IC/PBS in patients.

Leukotriene C4 induces bronchoconstriction and airway vascular hyperpermeability via the cysteinyl leukotriene receptor 2 in S-hexyl glutathione-treated guinea pigs

Cysteinyl leukotrienes act through G-protein-coupled receptors termed cysteinyl leukotriene 1 (CysLT1) and cysteinyl leukotriene 2 (CysLT2) receptors. However, little is known about the pathophysiological role of CysLT2 receptors in asthma. To elucidate the possible involvement of CysLT2 receptors in bronchoconstriction and airway vascular hyperpermeability, we have established a novel guinea pig model of asthma. In vitro study confirmed that CHO-K1 cells, expressing guinea pig CysLT2 and CysLT1 receptors are selectively stimulated by LTC4 and LTD4, respectively. However, when LTC4 was intravenously injected to guinea pigs, the resulting bronchoconstriction was fully abrogated by montelukast, a CysLT1 receptor antagonist, indicating rapid metabolism of LTC4 to LTD4 in the lung. We found that treatment with S-hexyl glutathione (S-hexyl GSH), an inhibitor of gamma-glutamyl transpeptidase, significantly increased LTC4 content and LTC4/(LTD4 plus LTE4) ratio in the lung. Under these circumstances, LTC4-induced bronchoconstriction became resistant to montelukast, but sensitive to Compound A, a CysLT2 receptor antagonist, depending on the dose of S-hexyl GSH. Combination with montelukast and Compound A completely abrogated this spasmogenic response. Additionally, we confirmed that LTC4 elicits airway vascular hyperpermeability via CysLT2 receptors in the presence of high dose of S-hexyl GSH as evidenced by complete inhibition of LTC4-induced hyperpermeability by Compound A, but not montelukast. These results suggest that CysLT2 receptors mediate bronchoconstriction and airway vascular hyperpermeability in guinea pigs and that the animal model used in this study may be useful to elucidate the functional role of CysLT2 receptors in various diseases, including asthma.

Discovery of Highly Potent Dual CysLT1 and CysLT2 Antagonist

The benzoxazine derivative, (2S)-4-(3-carboxypropyl)-8-{[4-(4-phenylbutoxy)benzoyl]amino}-3,4-dihydro-2H-1,4-benzoxazine-2-carboxylic acid (19, ONO-2050297), was identified as the first potent dual CysLT1 and CysLT2 antagonist with IC50 values of 0.017 μM (CysLT1) and 0.00087 μM (CysLT2), respectively.

Roles of basophils and mast cells infiltrating the lung by multiple antigen challenges in asthmatic responses of mice

BACKGROUND AND PURPOSE

Mast cell hyperplasia has been observed in the lungs of mice with experimental asthma, but few reports have studied basophils. Here, we attempted to discriminate and quantify mast cells and basophils in the lungs in a murine asthma model, determine if both cells were increased by multiple antigen challenges and assess the roles of those cells in asthmatic responses.

EXPERIMENTAL APPROACH

Sensitized Balb/c mice were intratracheally challenged with ovalbumin four times. Mast cells and basophils in enzymatically digested lung tissue were detected by flow cytometry. An anti-FcεRI monoclonal antibody, MAR-1, was i.p. administered during the multiple challenges.

KEY RESULTS

The numbers of both mast cells (IgE(+) C-kit(+) ) and basophils (IgE(+) C-kit(-) CD49b(+) ) increased in the lungs after three challenges. Treatment with MAR-1 completely abolished the increases; however, a late-phase increase in specific airway resistance (sRaw), and airway eosinophilia and neutrophilia were not affected by the treatment, although the early-phase increase in sRaw was suppressed. MAR-1 reduced antigen-induced airway IL-4 production. Basophils infiltrating the lung clearly produced IL-4 after antigen stimulation in vitro; however, histamine and murine mast cell protease 1 were not increased in the serum after the challenge, indicating that mast cell activation was not evoked.

CONCLUSION AND IMPLICATIONS

Both mast cells and basophils infiltrated the lungs by multiple intratracheal antigen challenges in sensitized mice. Neither mast cells nor basophils were involved in late-phase airway obstruction, although early-phase obstruction was mediated by basophils. Targeting basophils in asthma therapy may be useful for an early asthmatic response.

Purification and Characterization of a DNA-dependent RNA Polymerase fromPseudomonas putida

DNA-dependent RNA polymerase (EC 2.7.7.6) was purified from Pseudomonas putida. The enzyme had the typical composition of beta',beta,alpha, and sigma subunits of eubacterial RNA polymerases. The molecular masses of the subunits were 156,000 Da, 151,000 Da, 87,000 Da, and 42,000 Da, respectively, as measured by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The NH2-terminal amino acid residues of the alpha subunit had a marked homology with those of the alpha subunit of Escherichia coli RNA polymerase. The enzyme activity was dependent on ribonucleoside triphosphates, Mg2+, and a DNA template, and was inhibited in vitro by rifampicin. The enzyme activity was maximal in the presence of 10 mM MgCl2. In an in vitro transcription assay using the tac promoter-controlled DNA as a template, the RNA polymerase of P. putida initiated transcription at the same site as that of E. coli.