Adenine nucleotide-dependent regulation of assembly of bacterial tubulin-like FtsZ by a hypermorph of bacterial actin-like FtsA.

Cytokinesis in bacteria depends upon the contractile Z ring, which is composed of dynamic polymers of the tubulin homolog FtsZ as well as other membrane-associated proteins such as FtsA, a homolog of actin that is required for membrane attachment of the Z ring and its subsequent constriction. Here we show that a previously characterized hypermorphic mutant FtsA (FtsA*) partially disassembled FtsZ polymers in vitro. This effect was strictly dependent on ATP or ADP binding to FtsA* and occurred at substoichiometric levels relative to FtsZ, similar to cellular levels. Nucleotide-bound FtsA* did not affect FtsZ GTPase activity or the critical concentration for FtsZ assembly but was able to disassemble preformed FtsZ polymers, suggesting that FtsA* acts on FtsZ polymers. Microscopic examination of the inhibited FtsZ polymers revealed a transition from long, straight polymers and polymer bundles to mainly short, curved protofilaments. These results indicate that a bacterial actin, when activated by adenine nucleotides, can modify the length distribution of bacterial tubulin polymers, analogous to the effects of actin-depolymerizing factor/cofilin on F-actin

29 th Annual meeting of the Society for Immunotherapy of Cancer (SITC)

The 29 th annual meeting of the Society for Immunotherapy of Cancer (SITC) was held November 7-9, 2014 in National Harbor, MD and was organized by Dr. Arthur A. Hurwitz (National Cancer Institute), Dr. Kim A. Margolin (Stanford University), Dr. Daniel E. Speiser (Ludwig Center for Cancer Research, University of Lausanne) and Dr. Walter J. Urba (Earle A. Chiles Research Institute, Providence Cancer Center). This meeting included over 1,600 registered participants from 28 separate countries, making it the largest SITC meeting held to date. It highlighted significant worldwide progress in the development and application of cancer immunology to the practice of clinical oncology, including advances in diagnosis, prognosis and therapy, utilizing several immunological pathways and mechanisms for a variety of oncologic conditions. Presentations and posters demonstrated that many concepts that had been pursued preclinically in the past are now being translated into clinical practice, with clear benefits for patients

How to infer gene networks from expression profiles

Inferring, or ‘reverse-engineering', gene networks can be defined as the process of identifying gene interactions from experimental data through computational analysis. Gene expression data from microarrays are typically used for this purpose. Here we compared different reverse-engineering algorithms for which ready-to-use software was available and that had been tested on experimental data sets. We show that reverse-engineering algorithms are indeed able to correctly infer regulatory interactions among genes, at least when one performs perturbation experiments complying with the algorithm requirements. These algorithms are superior to classic clustering algorithms for the purpose of finding regulatory interactions among genes, and, although further improvements are needed, have reached a discreet performance for being practically useful

Residence Time Statistics for Normal and Fractional Diffusion in a Force Field

We investigate statistics of occupation times for an over-damped Brownian particle in an external force field. A backward Fokker-Planck equation introduced by Majumdar and Comtet describing the distribution of occupation times is solved. The solution gives a general relation between occupation time statistics and probability currents which are found from solutions of the corresponding problem of first passage time. This general relationship between occupation times and first passage times, is valid for normal Markovian diffusion and for non-Markovian sub-diffusion, the latter modeled using the fractional Fokker-Planck equation. For binding potential fields we find in the long time limit ergodic behavior for normal diffusion, while for the fractional framework weak ergodicity breaking is found, in agreement with previous results of Bel and Barkai on the continuous time random walk on a lattice. For non-binding potential rich physical behaviors are obtained, and classification of occupation time statistics is made possible according to whether or not the underlying random walk is recurrent and the averaged first return time to the origin is finite. Our work establishes a link between fractional calculus and ergodicity breaking.Comment: 12 page

Phase 2 study of RO4929097, a gamma‐secretase inhibitor, in metastatic melanoma: SWOG 0933

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110565/1/cncr29055.pd

TGFBR1*6A and Int7G24A variants of transforming growth factor-β receptor 1 in Swedish familial and sporadic breast cancer

Two common variants in transforming growth factor-β receptor 1 (TGFBR1), TGFBR1*6A and Int7G24A, A allele, have been shown to act as low-penetrance tumour susceptibility alleles in several common cancers, including breast cancer. We evaluated the TGFBR1 9A/6A and Int7G24A variant frequencies in two breast cancer cohorts; a population-based cohort of breast cancer with defined family history (n=459) and in breast cancer patients from a familial cancer clinic (n=340) and in 856 controls from the Stockholm region. The familial patients from both cohorts were further divided into high- and low-risk familial breast cancer based on pedigree analysis. There was no overall association with either variant and breast cancer risk. The TGFBR1*6A allelic frequency was, however, higher in low-risk familial breast cancer (0.138), compared to controls (0.106; P=0.04). No significant difference was found in the high-risk familial (0.102) or sporadic cases (0.109; P=0.83 and 0.83, respectively). TGFBR1*6A carrier status was further associated with a high-grade sporadic breast cancer (odds ratio: 2.27; 95% confidence interval: 1.01–5.11; P=0.049). These results indicate that the TGFBR1*6A variant may be associated with an increased risk of low-risk familial breast cancer and might be a marker for poorly differentiated breast cancer. The Int7G24A variant was not associated with breast cancer risk or clinical presentation of the disease including prognosis in our material

The melanoma-specific graded prognostic assessment does not adequately discriminate prognosis in a modern population with brain metastases from malignant melanoma

The melanoma-specific graded prognostic assessment (msGPA) assigns patients with brain metastases from malignant melanoma to 1 of 4 prognostic groups. It was largely derived using clinical data from patients treated in the era that preceded the development of newer therapies such as BRAF, MEK and immune checkpoint inhibitors. Therefore, its current relevance to patients diagnosed with brain metastases from malignant melanoma is unclear. This study is an external validation of the msGPA in two temporally distinct British populations.Performance of the msGPA was assessed in Cohort I (1997-2008, n=231) and Cohort II (2008-2013, n=162) using Kaplan-Meier methods and Harrell's c-index of concordance. Cox regression was used to explore additional factors that may have prognostic relevance.The msGPA does not perform well as a prognostic score outside of the derivation cohort, with suboptimal statistical calibration and discrimination, particularly in those patients with an intermediate prognosis. Extra-cerebral metastases, leptomeningeal disease, age and potential use of novel targeted agents after brain metastases are diagnosed, should be incorporated into future prognostic models.An improved prognostic score is required to underpin high-quality randomised controlled trials in an area with a wide disparity in clinical care

Cancer cells exploit an orphan RNA to drive metastatic progression.

Here we performed a systematic search to identify breast-cancer-specific small noncoding RNAs, which we have collectively termed orphan noncoding RNAs (oncRNAs). We subsequently discovered that one of these oncRNAs, which originates from the 3' end of TERC, acts as a regulator of gene expression and is a robust promoter of breast cancer metastasis. This oncRNA, which we have named T3p, exerts its prometastatic effects by acting as an inhibitor of RISC complex activity and increasing the expression of the prometastatic genes NUPR1 and PANX2. Furthermore, we have shown that oncRNAs are present in cancer-cell-derived extracellular vesicles, raising the possibility that these circulating oncRNAs may also have a role in non-cell autonomous disease pathogenesis. Additionally, these circulating oncRNAs present a novel avenue for cancer fingerprinting using liquid biopsies

Long-Term Survival after High-Dose Chemotherapy Followed by Peripheral Stem Cell Rescue for High-Risk, Locally Advanced/Inflammatory, and Metastatic Breast Cancer

Patients with high-risk locally advanced/inflammatory and oligometastatic (≤3 sites) breast cancer frequently relapse or experience early progression. High-dose chemotherapy combined with peripheral stem cell rescue may prolong progression-free survival/relapse-free survival (PFS/RFS) and overall survival (OS). In this study, patients initiated high-dose chemotherapy with STAMP-V (carboplatin, thiotepa, and cyclophosphamide), ACT (doxorubicin, paclitaxel, and cyclophosphamide), or tandem melphalan and STAMP-V. Eighty-six patients were diagnosed with locally advanced/inflammatory (17 inflammatory) breast cancer, and 12 were diagnosed with oligometastatic breast cancer. Median follow-up was 84 months (range, 6-136 months) for patients with locally advanced cancer and 40 months (range, 24-62 months) for those with metastatic cancer. In the patients with locally advanced cancer, 5-year RFS and OS were 53% (95% CI, 41%-63%) and 71% (95% CI, 60%-80%), respectively, hormone receptors were positive in 74%, and HER2 overexpression was seen in 23%. In multivariate analysis, hormone receptor–positive disease and lower stage were associated with better 5-year RFS (60% for ER [estrogen receptor]/PR [progesterone receptor]-positive versus 30% for ER/PR-negative; P < .01) and OS (83% for ER/PR-positive versus 38% for ER/PR-negative; P < .001). In the patients with metastatic cancer, 3-year PFS and OS were 49% (95% CI, 19%-73%) and 73% (95% CI, 38%-91%), respectively. The favorable long-term RFS/PFS and OS for high-dose chemotherapy with peripheral stem cell rescue in this selected patient population reflect the relative safety of the procedure and warrant validation in defined subgroups through prospective, randomized, multi-institutional trials