A novel approach to identify driver genes involved in androgen-independent prostate cancer

Abstract Background Insertional mutagenesis screens have been used with great success to identify oncogenes and tumor suppressor genes. Typically, these screens use gammaretroviruses (γRV) or transposons as insertional mutagens. However, insertional mutations from replication-competent γRVs or transposons that occur later during oncogenesis can produce passenger mutations that do not drive cancer progression. Here, we utilized a replication-incompetent lentiviral vector (LV) to perform an insertional mutagenesis screen to identify genes in the progression to androgen-independent prostate cancer (AIPC). Methods Prostate cancer cells were mutagenized with a LV to enrich for clones with a selective advantage in an androgen-deficient environment provided by a dysregulated gene(s) near the vector integration site. We performed our screen using an in vitro AIPC model and also an in vivo xenotransplant model for AIPC. Our approach identified proviral integration sites utilizing a shuttle vector that allows for rapid rescue of plasmids in E. coli that contain LV long terminal repeat (LTR)-chromosome junctions. This shuttle vector approach does not require PCR amplification and has several advantages over PCR-based techniques. Results Proviral integrations were enriched near prostate cancer susceptibility loci in cells grown in androgen-deficient medium (p < 0.001), and five candidate genes that influence AIPC were identified; ATPAF1, GCOM1, MEX3D, PTRF, and TRPM4. Additionally, we showed that RNAi knockdown of ATPAF1 significantly reduces growth (p < 0.05) in androgen-deficient conditions. Conclusions Our approach has proven effective for use in PCa, identifying a known prostate cancer gene, PTRF, and also several genes not previously associated with prostate cancer. The replication-incompetent shuttle vector approach has broad potential applications for cancer gene discovery, and for interrogating diverse biological and disease processes.http://deepblue.lib.umich.edu/bitstream/2027.42/109477/1/12943_2014_Article_1323.pd

Vision, challenges and opportunities for a Plant Cell Atlas

With growing populations and pressing environmental problems, future economies will be increasingly plant-based. Now is the time to reimagine plant science as a critical component of fundamental science, agriculture, environmental stewardship, energy, technology and healthcare. This effort requires a conceptual and technological framework to identify and map all cell types, and to comprehensively annotate the localization and organization of molecules at cellular and tissue levels. This framework, called the Plant Cell Atlas (PCA), will be critical for understanding and engineering plant development, physiology and environmental responses. A workshop was convened to discuss the purpose and utility of such an initiative, resulting in a roadmap that acknowledges the current knowledge gaps and technical challenges, and underscores how the PCA initiative can help to overcome them.</jats:p

Efficacy of Neutron Radiotherapy for Primary Tracheal Adenoid Cystic Carcinoma: A Single Institution Retrospective Analysis

Background: Primary adenoid cystic carcinoma (ACC) is the second most common primary tracheal neoplasms but the data for optimal treatment plan is limited. This study is an update of our institutional experience treating primary ACC of the trachea with neutron radiotherapy.Methods: Between 1993 and 2012, 33 patients with tracheal adenoid cystic carcinoma were treated with curative intent. Two patients received surgery alone, thirteen received adjuvant neutron radiotherapy post surgical resection, and eighteen received neutron radiotherapy as a primary treatment. Median external beam neutron dose was 19.2 Gy.Two patients who were treated with adjuvant neutron radiotherapy post surgical resection and nine patients treated with neutron radiotherapy alone were also treated with endobronchial brachytherapy boost using high-dose-rate 192Ir source (3.5Gy×2 fractions).Median duration of follow up was 72.4 months (range 0.9–145.9 months) post treatment.Results: Patients who underwent surgery alone, those who received adjuvant neutron radiotherapy post surgical resection, and patients who received neutron radiotherapy as a primary treatment had five-year overall survival rates of 50%, 49% and 93% (p=0.399), and five-year disease-free survival rates of 50%, 58% and 38% (p=0.702) respectively.The five-year overall survival rates and disease free survival rates for patients who received adjuvant high-dose-rate endobronchial brachytherapy in addition to primary treatment as compared to those who did not were 89% and 72% (p=0.489) versus 46% vs 44% (p=0.251) respectively.Conclusions: The data supports the conclusion that adenoid cystic carcinoma of the trachea can be treated with neutron radiation with favorable outcomes.</p

Inhibition of diacylglycerol kinase α restores restimulation-induced cell death and reduces immunopathology in XLP-1

X-linked lymphoproliferative disease (XLP-1) is an often-fatal primary immunodeficiency associated with the exuberant expansion of activated CD8+ T cells after Epstein-Barr virus (EBV) infection. XLP-1 is caused by defects in signaling lymphocytic activation molecule (SLAM)-associated protein (SAP), an adaptor protein that modulates T cell receptor (TCR) -induced signaling. SAP-deficient T cells exhibit impaired TCR restimulation-induced cell death (RICD) and diminished TCR-induced inhibition of diacylglycerol kinase α (DGKα), leading to increased diacylglycerol metabolism and decreased signaling through Ras and PKCθ (protein kinase Cθ). We show that down-regulation of DGKα activity in SAP-deficient T cells restores diacylglycerol signaling at the immune synapse and rescues RICD via induction of the proapoptotic proteins NUR77 and NOR1. Pharmacological inhibition of DGKα prevents the excessive CD8+ T cell expansion and interferon-γ production that occur in SAP-deficient mice after lymphocytic choriomeningitis virus infection without impairing lytic activity. Collectively, these data highlight DGKα as a viable therapeutic target to reverse the life-threatening EBV-associated immunopathology that occurs in XLP-1 patients