Metagenomic Analysis of the Bioremediation of Diesel-Contaminated Canadian High Arctic Soils

As human activity in the Arctic increases, so does the risk of hydrocarbon pollution events. On site bioremediation of contaminated soil is the only feasible clean up solution in these remote areas, but degradation rates vary widely between bioremediation treatments. Most previous studies have focused on the feasibility of on site clean-up and very little attention has been given to the microbial and functional communities involved and their ecology. Here, we ask the question: which microorganisms and functional genes are abundant and active during hydrocarbon degradation at cold temperature? To answer this question, we sequenced the soil metagenome of an ongoing bioremediation project in Alert, Canada through a time course. We also used reverse-transcriptase real-time PCR (RT-qPCR) to quantify the expression of several hydrocarbon-degrading genes. Pseudomonas species appeared as the most abundant organisms in Alert soils right after contamination with diesel and excavation (t = 0) and one month after the start of the bioremediation treatment (t = 1m), when degradation rates were at their highest, but decreased after one year (t = 1y), when residual soil hydrocarbons were almost depleted. This trend was also reflected in hydrocarbon degrading genes, which were mainly affiliated with Gammaproteobacteria at t = 0 and t = 1m and with Alphaproteobacteria and Actinobacteria at t = 1y. RT-qPCR assays confirmed that Pseudomonas and Rhodococcus species actively expressed hydrocarbon degradation genes in Arctic biopile soils. Taken together, these results indicated that biopile treatment leads to major shifts in soil microbial communities, favoring aerobic bacteria that can degrade hydrocarbons

Association of the Cold Shock DEAD-Box RNA Helicase RhlE to the RNA Degradosome in Caulobacter crescentus\textit{Caulobacter crescentus}

In diverse bacterial lineages, multienzyme assemblies have evolved that are central elements of RNA metabolism and RNA-mediated regulation. The aquatic Gram-negative bacterium $\textit{Caulobacter crescentus}$, which has been a model system for studying the bacterial cell cycle, has an RNA degradosome assembly that is formed by the endoribonuclease RNase E and includes the DEAD-box RNA helicase RhlB. Immunoprecipitations of extracts from cells expressing an epitope-tagged RNase E reveal that RhlE, another member of the DEAD-box helicase family, associates with the degradosome at temperatures below those optimum for growth. Phenotype analyses of rhlE, rhlB, and rhlE rhlB mutant strains show that RhlE is important for cell fitness at low temperature and its role may not be substituted by RhlB. Transcriptional and translational fusions of rhlE to the lacZ reporter gene and immunoblot analysis of an epitope-tagged RhlE indicate that its expression is induced upon temperature decrease, mainly through posttranscriptional regulation. RNase E pulldown assays show that other proteins, including the transcription termination factor Rho, a second DEAD-box RNA helicase, and ribosomal protein S1, also associate with the degradosome at low temperature. The results suggest that the RNA degradosome assembly can be remodeled with environmental change to alter its repertoire of helicases and other accessory proteins.IMPORTANCE DEAD-box RNA helicases are often present in the RNA degradosome complex, helping unwind secondary structures to facilitate degradation. Caulobacter crescentus is an interesting organism to investigate degradosome remodeling with change in temperature, because it thrives in freshwater bodies and withstands low temperature. In this study, we show that at low temperature, the cold-induced DEAD-box RNA helicase RhlE is recruited to the RNA degradosome, along with other helicases and the Rho protein. RhlE is essential for bacterial fitness at low temperature, and its function may not be complemented by RhlB, although RhlE is able to complement for rhlB loss. These results suggest that RhlE has a specific role in the degradosome at low temperature, potentially improving adaptation to this condition.This work was supported by the São Paulo Research Foundation (FAPESP, grant 2014/04046-8). During the course of this work, A.A.A. was supported by fellowship grant 1406343 from the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), A.M.V. was supported by fellowship grant 2014/13552-4 from FAPESP, D.M.A. was supported by fellowship grant PIBIC 123970/2010-5 from the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq-Brasil), S.W.H. and B.F.L. were supported by Wellcome Trust grant RG84381, and M.V.M. was partially supported by fellowship grant 306558/2013-0 from CNPq-Brazil

An update on the pharmacotherapy for endometrial cancer

Abstract INTRODUCTION: Endometrial cancer (EC) is the seventh most common malignancy in women. Most cases have a favorable prognosis because they present an early stage disease at diagnosis. Treatment currently comprises surgery with or without adjuvant approaches. A combination of radiation therapy, chemotherapy or hormonal therapy (HT) is usually administered. This article gives an update concerning the role of synthetic drugs in EC, reviewing the most recent data from Phase III randomized-controlled trials onwards. AREAS COVERED: Over the years, chemotherapy has become the treatment mainstay in both high-risk or locally advanced EC and in metastatic or recurrent disease. Carboplatin plus paclitaxel is currently considered the standard chemotherapy regimen with a well-tolerated toxicity profile. HT is an alternative option in women with advanced EC and important co-morbidities, and in young women with very early stage disease. EXPERT OPINION: Basic results of EC treatment during the last decade were collected. There is a need of more advances in treatment. The use of biomarkers, necessary for the success of a therapeutic strategy, and the identification of an ad-hoc population, are two important goals. In the authors' opinion, the development of comprehensive tumor bio-banks and international networks represent the right approach to foster translational studies and obtain improvement in patient outcomes