Phase I/II Study of Refametinib (BAY 86-9766) in Combination with Gemcitabine in Advanced Pancreatic cancer

Background Activating KRAS mutations are reported in up to 90% of pancreatic cancers. Refametinib potently inhibits MEK1/2, part of the MAPK signaling pathway. This phase I/II study evaluated the safety and efficacy of refametinib plus gemcitabine in patients with advanced pancreatic cancer. Methods Phase I comprised dose escalation, followed by phase II expansion. Refametinib and gemcitabine plasma levels were analyzed for pharmacokinetics. KRAS mutational status was determined from circulating tumor DNA. Results Ninety patients overall received treatment. The maximum tolerated dose was refametinib 50 mg twice daily plus standard gemcitabine (1000 mg/m2 weekly). The combination was well tolerated, with no pharmacokinetic interaction. Treatment-emergent toxicities included thrombocytopenia, fatigue, anemia, and edema. The objective response rate was 23% and the disease control rate was 73%. Overall response rate, disease control rate, progression-free survival, and overall survival were higher in patients without detectable KRAS mutations (48% vs. 28%, 81% vs. 69%, 8.8 vs. 5.3 months, and 18.2 vs. 6.6 months, respectively). Conclusion Refametinib plus gemcitabine was well tolerated, with a promising objective response rate, and had an acceptable safety profile and no pharmacokinetic interaction. There was a trend towards improved outcomes in patients without detectable KRAS mutations that deserves future investigation

Effect of Neoadjuvant Chemotherapy Followed by Surgical Resection on Survival in Patients With Limited Metastatic Gastric or Gastroesophageal Junction Cancer: The AIO-FLOT3 Trial

IMPORTANCE: Surgical resection has a potential benefit for patients with metastatic adenocarcinoma of the stomach and gastroesophageal junction. OBJECTIVE: To evaluate outcome in patients with limited metastatic disease who receive chemotherapy first and proceed to surgical resection. DESIGN, SETTING, AND PARTICIPANTS: The AIO-FLOT3 (Arbeitsgemeinschaft Internistische Onkologie-fluorouracil, leucovorin, oxaliplatin, and docetaxel) trial is a prospective, phase 2 trial of 252 patients with resectable or metastatic gastric or gastroesophageal junction adenocarcinoma. Patients were enrolled from 52 cancer care centers in Germany between February 1, 2009, and January 31, 2010, and stratified to 1 of 3 groups: resectable (arm A), limited metastatic (arm B), or extensive metastatic (arm C). Data cutoff was January 2012, and the analysis was performed in March 2013. INTERVENTIONS: Patients in arm A received 4 preoperative cycles of fluorouracil, leucovorin, oxaliplatin, and docetaxel (FLOT) followed by surgery and 4 postoperative cycles. Patients in arm B received at least 4 cycles of neoadjuvant FLOT and proceeded to surgical resection if restaging (using computed tomography and magnetic resonance imaging) showed a chance of margin-free (R0) resection of the primary tumor and at least a macroscopic complete resection of the metastatic lesions. Patients in arm C were offered FLOT chemotherapy and surgery only if required for palliation. Patients received a median (range) of 8 (1-15) cycles of FLOT. MAIN OUTCOMES AND MEASURES: The primary end point was overall survival. RESULTS: In total, 238 of 252 patients (94.4%) were eligible to participate. The median (range) age of participants was 66 (36-79) years in arm A (n = 51), 63 (28-79) years in arm B (n = 60), and 65 (23-83) years in arm C (n = 127). Patients in arm B (n = 60) had only retroperitoneal lymph node involvement (27 patients [45%]), liver involvement (11 [18.3%]), lung involvement (10 [16.7%]), localized peritoneal involvement (4 [6.7%]), or other (8 [13.3%]) incurable sites. Median overall survival was 22.9 months (95% CI, 16.5 to upper level not achieved) for arm B, compared with 10.7 months (95% CI, 9.1-12.8) for arm C (hazard ratio, 0.37; 95% CI, 0.25-0.55) (P < .001). The response rate for arm B was 60% (complete, 10%; partial, 50%), which is higher than the 43.3% for arm C. In arm B, 36 of 60 patients (60%) proceeded to surgery. The median overall survival was 31.3 months (95% CI, 18.9-upper level not achieved) for patients who proceeded to surgery and 15.9 months (95% CI, 7.1-22.9) for the other patients. CONCLUSIONS AND RELEVANCE: Patients with limited metastatic disease who received neoadjuvant chemotherapy and proceeded to surgery showed a favorable survival. The AIO-FLOT3 trial provides a rationale for further randomized clinical trials. TRIAL REGISTRATION: clinicaltrials.gov identifier: NCT00849615.info:eu-repo/semantics/publishedVersio

Differential activation of inflammatory pathways in A549 type II pneumocytes by Streptococcus pneumoniae strains with different adherence properties

BACKGROUND: Adherence of Streptococcus pneumoniae bacteria to lung cells is a first step in the progression from asymptomatic carriage to pneumonia. Adherence abilities vary widely among S. pneumoniae patient isolates. In this study, the binding properties of S. pneumoniae isolates and the effects of binding on activation of the Nuclear Factor-Kappa-B (NFκB) pathway and cytokine secretion by type II pneumocytes were measured. METHODS: Mechanisms of high- and low-binding S. pneumoniae adherence to A549 cells were investigated by blocking putative receptors on bacteria and host cells with antibody and by eluting choline-binding proteins off of bacterial surfaces. NFκB activation was measured by western blot and immunocytochemistry and cytokine secretion was detected by a protein array. RESULTS: This study shows that S. pneumoniae isolates from pneumonia patients (n = 298) can vary by as much as 1000-fold in their ability to bind to human lung epithelial cells. This difference resulted in differential activation of the NFκB pathway. High-, but not low-binding S. pneumoniae used Choline-binding protein A (CbpA) to bind to complement component C3 on epithelial cell surfaces. Interleukin-8 (IL-8) was the only cytokine secreted by cells treated with either low- or high-binding S. pneumoniae. CONCLUSION: These results indicate that S. pneumoniae clinical isolates are not homogeneous in their interaction with host epithelial cells. The differential activation of host cells by high- and low-binding S. pneumoniae strains could have implications for the treatment of pneumococcal pneumonia and for vaccine development

Conditional Immortalization of Human B Cells by CD40 Ligation

It is generally assumed that human differentiated cells have a limited life-span and proliferation capacity in vivo, and that genetic modifications are a prerequisite for their immortalization in vitro. Here we readdress this issue, studying the long-term proliferation potential of human B cells. It was shown earlier that human B cells from peripheral blood of healthy donors can be efficiently induced to proliferate for up to ten weeks in vitro by stimulating their receptor CD40 in the presence of interleukin-4. When we applied the same stimuli under conditions of modified cell number and culture size, we were surprised to find that our treatment induced B cells to proliferate throughout an observation period of presently up to 1650 days, representing more than 370 population doublings, which suggested that these B cells were immortalized in vitro. Long-term CD40-stimulated B cell cultures could be established from most healthy adult human donors. These B cells had a constant phenotype, were free from Epstein-Barr virus, and remained dependent on CD40 ligation. They had constitutive telomerase activity and stabilized telomere length. Moreover, they were susceptible to activation by Toll-like receptor 9 ligands, and could be used to expand antigen-specific cytotoxic T cells in vitro. Our results indicate that human somatic cells can evade senescence and be conditionally immortalized by external stimulation only, without a requirement for genetic manipulation or oncoviral infection. Conditionally immortalized human B cells are a new tool for immunotherapy and studies of B cell oncogenesis, activation, and function

Cell Proliferation in the Presence of Telomerase

BACKGROUND: Telomerase, which is active early in development and later in stem and germline cells, is also active in the majority of human cancers. One of the known functions of telomerase is to extend the ends of linear chromosomes, countering their gradual shortening at each cell division due to the end replication problem and postreplication processing. Telomerase concentration levels vary between different cell types as well as between different tumors. In addition variable telomerase concentrations will exist in different cells in the same tumor when telomerase inhibitors are used, because of limitations of drug delivery in tissue. Telomerase extends short telomeres more frequently than long telomeres and the relation between the extension frequency and the telomere length is nonlinear. METHODOLOGY/PRINCIPAL FINDINGS: Here, the biological data of the nonlinear telomerase-telomere dynamics is incorporated in a mathematical theory to relate the proliferative potential of a cell to the telomerase concentration in that cell. The main result of the paper is that the proliferative capacity of a cell grows exponentially with the telomerase concentration. CONCLUSIONS/SIGNIFICANCE: The theory presented here suggests that long term telomerase inhibition in every cancer progenitor or cancer stem cell is needed for successful telomere targeted cancer treatment. This theory also can be used to plan and assess the results of clinical trials targeting telomerase

Endothelial and Smooth Muscle Cells from Abdominal Aortic Aneurysm Have Increased Oxidative Stress and Telomere Attrition

Background: Abdominal aortic aneurysm (AAA) is a complex multi-factorial disease with life-threatening complications. AAA is typically asymptomatic and its rupture is associated with high mortality rate. Both environmental and genetic risk factors are involved in AAA pathogenesis. Aim of this study was to investigate telomere length (TL) and oxidative DNA damage in paired blood lymphocytes, aortic endothelial cells (EC), vascular smooth muscle cells (VSMC), and epidermal cells from patients with AAA in comparison with matched controls. Methods: TL was assessed using a modification of quantitative (Q)-FISH in combination with immunofluorescence for CD31 or α-smooth muscle actin to detect EC and VSMC, respectively. Oxidative DNA damage was investigated by immunofluorescence staining for 7, 8-dihydro-8-oxo-2′-deoxyguanosine (8-oxo-dG). Results and Conclusions: Telomeres were found to be significantly shortened in EC, VSMC, keratinocytes and blood lymphocytes from AAA patients compared to matched controls. 8-oxo-dG immunoreactivity, indicative of oxidative DNA damage, was detected at higher levels in all of the above cell types from AAA patients compared to matched controls. Increased DNA double strand breaks were detected in AAA patients vs controls by nuclear staining for γ-H2AX histone. There was statistically significant inverse correlation between TL and accumulation of oxidative DNA damage in blood lymphocytes from AAA patients. This study shows for the first time that EC and VSMC from AAA have shortened telomeres and oxidative DNA damage. Similar findings were obtained with circulating lymphocytes and keratinocytes, indicating the systemic nature of the disease. Potential translational implications of these findings are discussed. © 2012 Cafueri et al

Modelling the regulation of telomere length: the effects of telomerase and G-quadruplex stabilising drugs

Telomeres are guanine-rich sequences at the end of chromosomes which shorten during each replication event and trigger cell cycle arrest and/or controlled death (apoptosis) when reaching a threshold length. The enzyme telomerase replenishes the ends of telomeres and thus prolongs the life span of cells, but also causes cellular immortalisation in human cancer. G-quadruplex (G4) stabilising drugs are a potential anticancer treatment which work by changing the molecular structure of telomeres to inhibit the activity of telomerase. We investigate the dynamics of telomere length in different conformational states, namely t-loops, G-quadruplex structures and those being elongated by telomerase. By formulating deterministic differential equation models we study the effects of various levels of both telomerase and concentrations of a G4-stabilising drug on the distribution of telomere lengths, and analyse how these effects evolve over large numbers of cell generations. As well as calculating numerical solutions, we use quasicontinuum methods to approximate the behaviour of the system over time, and predict the shape of the telomere length distribution. We find those telomerase and G4-concentrations where telomere length maintenance is successfully regulated. Excessively high levels of telomerase lead to continuous telomere lengthening, whereas large concentrations of the drug lead to progressive telomere erosion. Furthermore, our models predict a positively skewed distribution of telomere lengths, that is, telomeres accumulate over lengths shorter than the mean telomere length at equilibrium. Our model results for telomere length distributions of telomerase-positive cells in drug-free assays are in good agreement with the limited amount of experimental data available

The Kuramoto model in complex networks

181 pages, 48 figures. In Press, Accepted Manuscript, Physics Reports 2015 Acknowledgments We are indebted with B. Sonnenschein, E. R. dos Santos, P. Schultz, C. Grabow, M. Ha and C. Choi for insightful and helpful discussions. T.P. acknowledges FAPESP (No. 2012/22160-7 and No. 2015/02486-3) and IRTG 1740. P.J. thanks founding from the China Scholarship Council (CSC). F.A.R. acknowledges CNPq (Grant No. 305940/2010-4) and FAPESP (Grants No. 2011/50761-2 and No. 2013/26416-9) for financial support. J.K. would like to acknowledge IRTG 1740 (DFG and FAPESP).Peer reviewedPreprin