Colon cancer cell-derived 12(S)-HETE induces the retraction of cancer-associated fibroblast via MLC2, RHO/ROCK and Ca2+ signalling

Retraction of mesenchymal stromal cells supports the invasion of colorectal cancer cells (CRC) into the adjacent compartment. CRC-secreted 12(S)-HETE enhances the retraction of cancer-associated fibroblasts (CAFs) and therefore, 12(S)-HETE may enforce invasivity of CRC. Understanding the mechanisms of metastatic CRC is crucial for successful intervention. Therefore, we studied pro-invasive contributions of stromal cells in physiologically relevant three-dimensional in vitro assays consisting of CRC spheroids, CAFs, extracellular matrix and endothelial cells, as well as in reductionist models. In order to elucidate how CAFs support CRC invasion, tumour spheroid-induced CAF retraction and free intracellular Ca2+ levels were measured and pharmacological-or siRNA-based inhibition of selected signalling cascades was performed. CRC spheroids caused the retraction of CAFs, generating entry gates in the adjacent surrogate stroma. The responsible trigger factor 12(S)-HETE provoked a signal, which was transduced by PLC, IP3, free intracellular Ca2+, Ca(2+)calmodulin-kinase-II, RHO/ROCK and MYLK which led to the activation of myosin light chain 2, and subsequent CAF mobility. RHO activity was observed downstream as well as upstream of Ca2+ release. Thus, Ca2+ signalling served as central signal amplifier. Treatment with the FDA-approved drugs carbamazepine, cinnarizine, nifedipine and bepridil HCl, which reportedly interfere with cellular calcium availability, inhibited CAF-retraction. The elucidation of signalling pathways and identification of approved inhibitory drugs warrant development of intervention strategies targeting tumour-stroma interaction

Malaria in Nonimmune Travelers

Background: With the current increase of international travel to tropical endemic areas, the incidence of malaria being imported into nonendemic countries has increased significantly. Disagreement concerning malaria chemoprophylaxis and inadequate knowledge of malarious areas, morbidity, and pretravel advise has led to confusion among both health professionals as well as travelers. Therefore, this study was conducted to investigate malaria imported into Germany by identifying the high-risk endemic areas, clinical presentations, and chemoprophylactic and therapeutic regimens related to reported cases. Methods: Between 1990 and 1993, the 160 nonimmune travelers, all German nationals or residents for more than 10 years, presenting to our travel clinic with microscopically confirmed malaria were investigated. For each, the travel history, chemoprophylaxis used during travel, symptoms, pathological diagnosis, and treatment efficacy were analyzed. Results: Africa (73%), Asia (21%), and Central South America (6%) were the endemic countries visited by our patients, of whom only 3% used the chemoprophylaxis recommended for their destination. Plasmodium falciparum was the most common pathogen, found in more than half of our patients, and P. vivax (29%), P. ova le (6%), P. malariae(6%), a mixed infection with P.falciparum and P vivax (3%) were also detected. All patients presented with fever and headaches, a majority with profuse night sweats, insomnia, arthralgias, and myalgias, and diarrhea and abdominal cramps were experienced in 13% and 8%, respectively. In falciparum malaria, a recrudescence was observed in all patients who received chloroquine only, whereas quinine, halofantrine, and mefloquine were highly effective. In vivax malaria, a relapse rate of 14% was noted in the patients treated with the currently recommended regimen of chloroquine and primaquine. Conclusions: Visitors to endemic countries, especially to Africa, are of significant risk. Given the low compliance rate of chemoprophylaxis, a high percentage of malaria in our patients could have been avoided by an appropriate prophylaxis regimen and optimal pretravel counseling

Peritumoral administration of GPI-anchored TIMP-1 inhibits colon carcinoma growth in Rag-2 gamma chain-deficient mice

Exogenous application of recombinant TIMP-1 protein modified by addition of a glycosylphosphatidylinositol (GPI) anchor allows efficient insertion of the fusion protein into cell membranes. This `cell surface engineering' leads to changes in the proteolytic environment. TIMP-1-GPI shows enhanced as well as novel in vitro biological activities including suppression of proliferation, reduced migration, and inhibition of invasion of the colon carcinoma cell line SW480. Treatment of SW480 tumors implanted in Rag (-/-) common gamma chain (-/-) C57BL/6 mice with peritumorally applied TIMP-1-GPI, control rhTIMP-1 protein, or vehicle shows that TIMP-1-GPI leads to a significant reduction in tumor growth

Coordination Chemistry of Perhalogenated Cyclopentadienes and Alkynes. 17. Reaction of Dichloroethyne With Platinum(0) Phosphine Complexes: Formation of a .pi.-Complex, Isomerization to .beta.-Chloroethynyl Complexes, and Syntheses of Diplatinioethyne Derivatives. Molecular Structures of (Ph3P)2Pt(.eta.2-ClC.tplbond.CCl) and Cl(Ph3P)2PtC.tplbond.CPt(PPh3)2Cl

Dichloroethyne ClCECCl reacts with Pt(PPh3)2(C2H4) or Pt(PPh& to give the a-complex Pt(PPh3)2(+21C=CC1) (l),w hich can be isomerized by prolonged refluxing in toluene to trans- (Ph3P)zC1Pt-C==CC1 (2). 2 easily undergoes exchange reactions with alkylphosphines and with halide anions to yield trans-(R3P)2ClPt-C=CCl (R = Et (3)) Bu (4)) and trans-(Ph3P)z- (X)Pt-C=CCl (X = F (5a), Br (5b), I (5c)), respectively. The alkylphosphine complexes 3 and 4 can also be obtained by reaction of Pt(PR3)4 (R = Et, “Bu) with ClCECCl or from 1 and the corresponding phosphine. When Pt(PPh&(CzH4) is added to a solution of 3, a dinuclear complex 6 is formed, in which the C=C-Cl group acts as a a,a-bridging ligand. Upon standing, oxidative addition of the remaining C-C1 bond occurs and the p-ethynediyl complex trans- C1(R3P)2Pt-C=C-Pt(PPh3)2C1-Cis (R = Et (7a)) can be obtained. The corresponding p-ethynediyl complex 7b (R = Ph) is formed directly from 2 and Pt(PPh&(CzH4). 7b isomerizes upon heating in toluene to the symmetrical all-trans isomer 8. The molecular structures of 1 and 8 were determined by X-ray diffraction (1: C ~ ~ H ~ ~ C ~ Z P ~ Pa ~=C 10H.3Z11C(3~) AZ,, b = 10.392(4) A, c = 33.675(16) A, P = 90.17(3)’, monoclinic, P21/n, 2 = 4. 8: C74H&1zP4Ptz9 a = 12.938(2) A, b = 19.964(3) A, c = 24.844(3) A, P = 96.14(1)’, monoclinic, C2/c, 2 = 4)

Chemokines (CCL3, CCL4, CCL5) inhibit ATP-induced release of IL-1beta by monocytic cells

ATP and chemokines are among the first inflammatory mediators that can enter the circulation via damaged blood vessels at the site of injury, leading to an activation of the host’s immune response. The main function of chemokines is leukocyte mobilization, guiding immune cells towards the injured tissue along a chemotactic concentration gradient. In monocytes, ATP typically triggers inflammasome assembly, a multiprotein complex necessary for the maturation and secretion of IL-1beta. IL-1beta is a potent inflammatory cytokine of innate immunity, essential for pathogen defense. However, excessive IL-1beta may cause life-threatening systemic inflammation. Here, we hypothesize that chemokines control ATP-dependent secretion of monocytic IL-1beta, by engaging a cholinergic signaling pathway. LPS-primed human monocytic U937 cells were treated with chemokines in the presence or absence of nAChR antagonists or iPLA2beta inhibitors and concomitantly stimulated with the P2X7 agonist BzATP. IL-1beta concentration was determined in the cell culture supernatants. Silencing of the chemokine receptor and iPLA2b gene expression was achieved by transfecting cells with the appropriate siRNA. CCL3, CCL4, and CCL5 dose-dependently inhibited BzATP-stimulated release of IL-1beta, whereas CXCL16 was ineffective. The effect of CCL3 was confirmed for primary mononuclear leukocytes. The inhibitory effect of CCL3 was blunted after silencing CCR1 or iPLA2beta gene expression by siRNA and was sensitive to antagonists of nAChRs containing subunits alpha7 and alpha9/alpha10. U937 cells secreted small factors in response to CCL3 that mediated the inhibition of IL-1beta release. We suggest that CCL chemokines inhibit ATP-induced release of IL-1beta from U937 cells by a triple-membrane-passing mechanism involving CCR, iPLA2, release of small mediators, and nAChR subunits alpha7 and alpha9/alpha10. We speculate that whenever chemokines and ATP enter the circulation concomitantly, systemic release of IL-1beta is minimized

The Mellin Transform Technique for the Extraction of the Gluon Density

A new method is presented to determine the gluon density in the proton from jet production in deeply inelastic scattering. By using the technique of Mellin transforms not only for the solution of the scale evolution equation of the parton densities but also for the evaluation of scattering cross sections, the gluon density can be extracted in next-to-leading order QCD. The method described in this paper is, however, more general, and can be used in situations where a repeated fast numerical evaluation of scattering cross sections for varying parton distribution functions is required.Comment: 13 pages (LaTeX); 2 figures are included via epsfig; the corresponding postscript files are uuencode

The heats of formation of the haloacetylenes XCCY [X, Y = H, F, Cl]: basis set limit ab initio results and thermochemical analysis

The heats of formation of haloacetylenes are evaluated using the recent W1 and W2 ab initio computational thermochemistry methods. These calculations involve CCSD and CCSD(T) coupled cluster methods, basis sets of up to spdfgh quality, extrapolations to the one-particle basis set limit, and contributions of inner-shell correlation, scalar relativistic effects, and (where relevant) first-order spin-orbit coupling. The heats of formation determined using W2 theory are: \hof(HCCH) = 54.48 kcal/mol, \hof(HCCF) = 25.15 kcal/mol, \hof(FCCF) = 1.38 kcal/mol, \hof(HCCCl) = 54.83 kcal/mol, \hof(ClCCCl) = 56.21 kcal/mol, and \hof(FCCCl) = 28.47 kcal/mol. Enthalpies of hydrogenation and destabilization energies relative to acetylene were obtained at the W1 level of theory. So doing we find the following destabilization order for acetylenes: FCCF $>$ ClCCF $>$ HCCF $>$ ClCCCl $>$ HCCCl $>$ HCCH. By a combination of W1 theory and isodesmic reactions, we show that the generally accepted heat of formation of 1,2-dichloroethane should be revised to -31.8$\pm$0.6 kcal/mol, in excellent agreement with a very recent critically evaluated review. The performance of compound thermochemistry schemes such as G2, G3, G3X and CBS-QB3 theories has been analyzed.Comment: Mol. Phys., in press (E. R. Davidson issue

Impairment of germline transmission after blastocyst injection with murine embryonic stem cells cultured with mouse hepatitis virus and mouse minute virus

The aim of this study was to determine the susceptibility of murine embryonic stem (mESCs) to mouse hepatitis virus (MHV-A59) and mouse minute virus (MMVp) and the effect of these viruses on germline transmission (GLT) and the serological status of recipients and pups. When recipients received 10 blastocysts, each injected with 100 TCID50 MHV-A59, three out of five recipients and four out of 14 pups from three litters became seropositive. When blastocysts were injected with 10−5 TCID50 MMVp, all four recipients and 14 pups from four litters remained seronegative. The mESCs replicated MHV-A59 but not MMVp, MHV-A59 being cytolytic for mESCs. Exposure of mESCs to the viruses over four to five passages but not for 6 h affected GLT. Recipients were seropositive for MHV-A59 but not for MMVp when mESCs were cultured with the virus over four or five passages. The data show that GLT is affected by virus-contaminated mESCs

Spatiotemporally restricted arenavirus replication induces immune surveillance and type I interferon-dependent tumour regression

Immune-mediated effector molecules can limit cancer growth, but lack of sustained immune activation in the tumour microenvironment restricts antitumour immunity. New therapeutic approaches that induce a strong and prolonged immune activation would represent a major immunotherapeutic advance. Here we show that the arenaviruses lymphocytic choriomeningitis virus (LCMV) and the clinically used Junin virus vaccine (Candid#1) preferentially replicate in tumour cells in a variety of murine and human cancer models. Viral replication leads to prolonged local immune activation, rapid regression of localized and metastatic cancers, and long-term disease control. Mechanistically, LCMV induces antitumour immunity, which depends on the recruitment of interferon-producing Ly6C+ monocytes and additionally enhances tumour-specific CD8+ T cells. In comparison with other clinically evaluated oncolytic viruses and to PD-1 blockade, LCMV treatment shows promising antitumoural benefits. In conclusion, therapeutically administered arenavirus replicates in cancer cells and induces tumour regression by enhancing local immune responses