A randomised comparison of novolimus-eluting and zotarolimus-eluting coronary stents: 9-month follow-up results of the EXCELLA II study

Novolimus, a macrocyclic lactone with anti-proliferative properties, has a similar efficacy to currently available agents; however it requires a lower dose, and less polymer, and is therefore conceivably safer.

Targeting siglecs--a novel pharmacological strategy for immuno- and glycotherapy

The immune system must be tightly held in check to avoid bystander tissue damage as well as autoreactivity caused by overwhelming immune reactions. A novel family of immunoregulatory, carbohydrate-binding receptors, the Siglecs (sialic acid binding immunoglobulin-like lectins), has received particular attention in light of their capacity to mediate cell death, anti-proliferative effects and to regulate a variety of cellular activities. Siglec receptors are mainly expressed on leukocytes in a cell type-specific and differentiation-dependent manner. Siglecs might potentially be exploited as targets of novel immune- and glycotherapeutics for cell-directed therapies in autoimmune and allergic diseases, as well as in haematologic malignancies. Here we present novel insights on structural and functional characteristics, expression patterns and evolutionary aspects of Siglecs and their ligands. Pharmacological strategies using Siglec agonistic cross-linking therapeutics, such as monoclonal or engineered antibodies, intravenous immunoglobulin (IVIG), or glycomimetics are discussed. Modulation of immune responses by targeting Siglecs using agonistic or antagonistic therapeutics may have important clinical implications and may pave the way for novel pharmacological avenues for the treatment of autoimmune and allergic diseases or for tumor immunotherapy.

Baicalein, a component of Scutellaria baicalensis, induces apoptosis by Mcl-1 down-regulation in human pancreatic cancer cells

Scutellaria baicalensis (SB) and SB-derived polyphenols possess anti-proliferative activities in several cancers, including pancreatic cancer (PaCa). However, the precise molecular mechanisms have not been fully defined. SB extract and SB-derived polyphenols (wogonin, baicalin, and baicalein) were used to determine their anti-proliferative mechanisms. Baicalein significantly inhibited the proliferation of PaCa cell lines in a dose-dependent manner, whereas wogonin and baicalin exhibited a much less robust effect. Treatment with baicalein induced apoptosis with release of cytochrome c from mitochondria, and activation of caspase-3 and -7 and PARP. The general caspase inhibitor zVAD-fmk reversed baicalein-induced apoptosis, indicating a caspase-dependent mechanism. Baicalein decreased expression of Mcl-1, an anti-apoptotic member of the Bcl-2 protein family, presumably through a transcriptional mechanism. Genetic knockdown of Mcl-1 resulted in marked induction of apoptosis. The effect of baicalein on apoptosis was significantly attenuated by Mcl-1 over-expression, suggesting a critical role of Mcl-1 in this process. Our results provide evidence that baicalein induces apoptosis in pancreatic cancer cells through down-regulation of the anti-apoptotic Mcl-1 protein.

Quassinoids: From traditional drugs to new cancer therapeutics

Quassinoids are a group of compounds extracted from plants of the Simaroubaceae family, which have been used for many years in folk medicine. These molecules gained notoriety after the initial discovery of the anti-leukemic activity of one member, bruceantin, in 1975. Currently over 150 quassinoids have been isolated and classified based on their chemical structures and biological properties investigated in vitro and in vivo. Many molecules display a wide range of inhibitory effects, including anti-inflammatory, anti-viral, anti-malarial and anti-proliferative effects on various tumor cell types. Although often the exact mechanism of action of the single agents remains unclear, some agents have been shown to affect protein synthesis in general, or specifically HIF-1α and MYC, membrane polarization and the apoptotic machinery. Considering that future research into chemical modifications is likely to generate more active and less toxic derivatives of natural quassinoids, this family represents a powerful source of promising small molecules targeting key prosurvival signaling pathways relevant for diverse pathologies. Here, we review available knowledge of functionality and possible applications of quassinoids and quassinoid derivatives, spanning traditional use to the potential impact on modern medicine as cancer therapeutics.

Novel agents targeting the IGF-1R/PI3K pathway impair cell proliferation and survival in subsets of medulloblastoma and neuroblastoma

The receptor tyrosine kinase (RTK)/phosphoinositide 3-kinase (PI3K) pathway is fundamental for cancer cell proliferation and is known to be frequently altered and activated in neoplasia, including embryonal tumors. Based on the high frequency of alterations, targeting components of the PI3K signaling pathway is considered to be a promising therapeutic approach for cancer treatment. Here, we have investigated the potential of targeting the axis of the insulin-like growth factor-1 receptor (IGF-1R) and PI3K signaling in two common cancers of childhood: neuroblastoma, the most common extracranial tumor in children and medulloblastoma, the most frequent malignant childhood brain tumor. By treating neuroblastoma and medulloblastoma cells with R1507, a specific humanized monoclonal antibody against the IGF-1R, we could observe cell line-specific responses and in some cases a strong decrease in cell proliferation. In contrast, targeting the PI3K p110α with the specific inhibitor PIK75 resulted in broad anti-proliferative effects in a panel of neuro- and medulloblastoma cell lines. Additionally, sensitization to commonly used chemotherapeutic agents occurred in neuroblastoma cells upon treatment with R1507 or PIK75. Furthermore, by studying the expression and phosphorylation state of IGF-1R/PI3K downstream signaling targets we found down-regulated signaling pathway activation. In addition, apoptosis occurred in embryonal tumor cells after treatment with PIK75 or R1507. Together, our studies demonstrate the potential of targeting the IGF-1R/PI3K signaling axis in embryonal tumors. Hopefully, this knowledge will contribute to the development of urgently required new targeted therapies for embryonal tumors.

Synthesis and cytotoxic activity of non-naturally substituted 4-oxycoumarin derivatives

Coumarins are a large family of natural and synthetic compounds exerting different pharmacological effects, including cytotoxic, anti-inflammatory or antimicrobial. In the present communication we report the synthesis of a series of 12 diversely substituted 4-oxycoumarin derivatives including methoxy substituted 4-hydroxycoumarins, methyl, methoxy or unsubstituted 3-aryl-4-hydroxycoumarins and 4-benzyloxycoumarins and their anti-proliferative effects on breast adenocarcinoma cells (MCF-7), human promyelocytic leukemia cells (HL-60), human histiocytic lymphoma cells (U937) and mouse neuroblastoma cells (Neuro2a). The most potent bioactive molecule was the 4-hydroxy-5,7-dimethoxycoumarin (compound 1) which showed similar potency (IC(50) 0.2-2 μM) in all cancer cell lines tested. This non-natural product reveals a simple bioactive scaffold which may be exploited in further studies.

Inhibition of hepatic tumor cell proliferation in vitro and tumor growth in vivo by taltobulin, a synthetic analogue of the tripeptide hemiasterlin

AIM: To investigate the inhibitory effects of taltobulin (HTI-286), a synthetic analogue of natural hemiasterlin derived from marine sponges, on hepatic tumor growth in vitro and in vivo. METHODS: The potential anti-proliferative effects of HTI-286 on different hepatic tumor cell lines in vitro and in vivo were examined. RESULTS: HTI-286 significantly inhibited proliferation of all three hepatic tumor cell lines (mean IC50 = 2 nmol/L +/- 1 nmol/L) in vitro. Interestingly, no decrease in viable primary human hepatocytes (PHH) was detected under HTI-286 exposure. Moreover, intravenous administration of HTI-286 significantly inhibited tumor growth in vivo (rat allograft model). CONCLUSION: HTI-286 might be considered a potent promising drug in treatment of liver malignancies. HTI-286 is currently undergoing clinical evaluation in cancer patients.

Future treatment strategies in ST-segment elevation myocardial infarction

Over the past five decades, management of acute ST-segment elevation myocardial infarction (STEMI) has evolved substantially. Current treatment encompasses a systematic chain of network activation, antithrombotic drugs, and rapid instigation of mechanical reperfusion, although pharmacoinvasive strategies remain relevant. Secondary prevention with drugs and lifestyle modifications completes the contemporary management package. Despite a tangible improvement in outcomes, STEMI remains a frequent cause of morbidity and mortality, justifying the quest to find new therapeutic avenues. Ways to reduce delays in doing coronary angioplasty after STEMI onset include early recognition of symptoms by patients and prehospital diagnosis by paramedics so that the emergency room can be bypassed in favour of direct admission to the catheterisation laboratory. Mechanical reperfusion can be optimised by improvements to stent design, whereas visualisation of infarct size has been improved by developments in cardiac MRI. Novel treatments to modulate the inflammatory component of atherosclerosis and the vulnerable plaque include use of bioresorbable vascular scaffolds and anti-proliferative drugs. Translational efforts to improve patients' outcomes after STEMI in relation to cardioprotection, cardiac remodelling, and regeneration are also being realised. This is the third in a Series of three papers about ST-segment elevation myocardial infarction.

Ceramide kinase contributes to proliferation but not to prostaglandin E2 formation in renal mesangial cells and fibroblasts

Background/Aims: Ceramide kinase (CerK) catalyzes the generation of the sphingolipid ceramide-1-phosphate (C1P) which regulates various cellular functions including cell growth and death, and inflammation. Here, we used a novel catalytic inhibitor of CerK, NVP-231, and CerK knockout cells to investigate the contribution of CerK to proliferation and inflammation in renal mesangial cells and fibroblasts. Methods: Cells were treated with NVP-231 and [3H]-thymidine incorporation into DNA, [3H]-arachidonic acid release, prostaglandin E2 (PGE2) synthesis, cell cycle distribution, and apoptosis were determined. Results: Treatment of rat mesangial cells and mouse renal fibroblasts with NVP-231 decreased DNA synthesis, but not of agonist-stimulated arachidonic acid release or PGE2 synthesis. Similarly, proliferation but not arachidonic acid release or PGE2 synthesis was reduced in CERK knockout renal fibroblasts. The anti-proliferative effect of NVP-231 on mesangial cells was due to M phase arrest as determined using the mitosis markers phospho-histone H3, cdc2 and polo-like kinase-1, and induction of apoptosis. Moreover, loss of CerK sensitized cells towards stress-induced apoptosis. Conclusions: Our data demonstrate that CerK induces proliferation but not PGE2 formation of renal mesangial cells and fibroblasts, and suggest that targeted CerK inhibition has potential for treating mesangioproliferative kidney diseases.

Diagnosis and workup of 522 consecutive patients with neuroendocrine neoplasms in Switzerland.

BACKGROUND Neuroendocrine neoplasms (NENs) are difficult to diagnose. We used SwissNET data to characterise NEN patients followed in the two academic centres of western Switzerland (WS), and to compare them with patients followed in eastern Switzerland (ES) as well as with international guidelines. METHOD SwissNET is a prospective database covering data from 522 consecutive patients (285 men, 237 women) from WS (n = 99) and ES (n = 423). RESULTS Mean ± SD age at diagnosis was 59.0 ± 15.7 years. Overall, 76/522 experienced a functional syndrome, with a median interval of 1.0 (IQR: 1.0-3.0) year between symptoms onset and diagnosis. A total of 51/522 of these tumours were incidental. The primary tumour site was the small intestine (29%), pancreas (21%), appendix (18%) and lung (11%) in both regions combined. In all, 513 functional imaging studies were obtained (139 in WS, 374 in ES). Of these, 381 were 111In-pentetreotide scintigraphies and 20 were 68Ga-DOTATOC PET. First line therapy was surgery in 87% of patients, medical therapy (biotherapy or chemotherapy) in 9% and irradiation in 3% for both regions together. CONCLUSION Swiss NEN patients appear similar to what has been described in the literature. Imaging by somatostatin receptor scintigraphy (SRS) is widely used in both regions of Switzerland. In good accordance with published guidelines, data on first line therapy demonstrate the crucial role of surgery. The low incidence of biotherapy suggests that long-acting somatostatin analogues are not yet widely used for their anti-proliferative effects. The SwissNET initiative should help improve compliance with ENETS guidelines in the workup and care of NEN patients.

KRAS and HRAS mutations confer resistance to MET targeting in preclinical models of MET-expressing tumor cells.

The MET receptor tyrosine kinase is often deregulated in human cancers and several MET inhibitors are evaluated in clinical trials. Similarly to EGFR, MET signals through the RAS-RAF-ERK/MAPK pathway which plays key roles in cell proliferation and survival. Mutations of genes encoding for RAS proteins, particularly in KRAS, are commonly found in various tumors and are associated with constitutive activation of the MAPK pathway. It was shown for EGFR, that KRAS mutations render upstream EGFR inhibition ineffective in EGFR-positive colorectal cancers. Currently, there are no clinical studies evaluating MET inhibition impairment due to RAS mutations. To test the impact of RAS mutations on MET targeting, we generated tumor cells responsive to the MET inhibitor EMD1214063 that express KRAS G12V, G12D, G13D and HRAS G12V variants. We demonstrate that these MAPK-activating RAS mutations differentially interfere with MET-mediated biological effects of MET inhibition. We report increased residual ERK1/2 phosphorylation indicating that the downstream pathway remains active in presence of MET inhibition. Consequently, RAS variants counteracted MET inhibition-induced morphological changes as well as anti-proliferative and anchorage-independent growth effects. The effect of RAS mutants was reversed when MET inhibition was combined with MEK inhibitors AZD6244 and UO126. In an in vivo mouse xenograft model, MET-driven tumors harboring mutated RAS displayed resistance to MET inhibition. Taken together, our results demonstrate for the first time in details the role of KRAS and HRAS mutations in resistance to MET inhibition and suggest targeting both MET and MEK as an effective strategy when both oncogenic drivers are expressed.

Single application of low-dose mycophenolate mofetil-OX7-immunoliposomes ameliorates experimental mesangial proliferative glomerulonephritis

IgA nephropathy, one of the most frequent forms of glomerulonephritis, characterized by mesangial hypercellularity and glomerular extracellular matrix (ECM) expansion, often leads to end-stage renal disease over a prolonged period. We investigated whether antiproliferative treatment in a single low dose specifically targeted to the glomerular mesangium by immunoliposomes (ILs) results in an amelioration of mesangial proliferative glomerulonephritis in rats (anti-Thy1.1 nephritis). Mycophenolate mofetil (MMF) containing ILs was generated that targets the Thy1.1 antigen (OX-7) in rat mesangial cells. Treatment benefit of a single intravenous dose of these ILs given 2 days after disease induction was investigated by stereology, immunohistochemistry, and functional analyses (creatinine, albuminuria) until day +9 and was compared among untreated and free MMF-treated rats using six male Wistar rats per group. MMF-loaded OX7-IL prevented creatinine increase and albuminuria. Stereological analyses of MMF OX7-IL-treated animals yielded 30% reduction of mesangial cells on day +9 and a 40% reduction of glomerular ECM volume on day +5, compared with all of the other nephritic animals. Furthermore, at days +5 and +9 we observed decreased ECM content and decreased glomerular volume (day +5) in the MMF-OX7-IL-treated group compared with the nephritic group treated with free MMF. In conclusion, MMF-OX7-IL-based directed drug delivery represents a novel approach for treating mesangial cell-mediated forms of glomerulonephritis.

Impact of culture conditions on the proliferative lifespan of human T cells in vitro

BACKGROUND: In human T cells, telomerase is transiently expressed upon activation and stimulation and, as shown previously, telomerase levels are able to control the lifespan of T cells. To improve T-cell expansion it is of critical importance to understand the effects of culture parameters on telomerase activity and lifespan. METHODS: We investigated the influence of culture condition (FCS, human AB serum and autologous serum) and stimulation (PHA/feeder cells, anti-CD3/CD28 beads) on the lifespan, clonogenicity (number of positive wells), cell cycle, telomerase activity and telomere length of T cells in vitro. RESULTS: The proliferative lifespan of T cells expanded with PHA/feeder cells and autologous serum from different donors was doubled compared with stimulation with PHA/feeder cells and AB serum. No or only a small difference was found for T cells expanded with anti-CD3/CD28 beads and autologous or AB serum. The use of autologous serum also increased the clonogenicity to about three-fold compared with the use of AB serum or FCS, without any signs of differences in the fractions of cycling cells. Interestingly, T cells cultured with autologous serum exhibited a significantly higher telomerase activity at day 6 after stimulation and a reduced decline of telomerase activity compared with cultures with AB serum. DISCUSSION: The use of autologous serum combined with PHA stimulation and feeder cells remarkably extends the proliferative lifespan and clonogenicity and increases the telomerase activity of human T cells in vitro. This might be useful for applications where large numbers of specific T cells are required.