Induction of Colon Cancer Cell Death by Cranberry Proanthocyanidins via MAPK Pathway

The potential ability of dietary cranberry to inhibit colon carcinogenesis is under investigation. Compounds isolated from locally grown cranberry fruit (Vaccinium macrocarpon) have been shown in vitro to decrease proliferation of colon cancer cells, in part by induction of apoptosis. These compounds include oligomeric polyphenols known as proanthocyanidins (PACs) containing two or more epicatechin units with different types of linkages. To further elucidate the mechanism by which PACs induce cell death, we transcriptionally profiled cells treated with PACs. HCT116 and HT29 colon cancer cells were exposed to a cranberry proanthocyanidin (PACs) fraction isolated from Early Black variety cranberry fruit, at time intervals of 6, 12, 18 and 24 hours. Total RNA was extracted from PAC-treated and untreated control cells. Transcriptional profiling was performed using an Illumina microarray bead system. Microarray results revealed that expression of several members of the mitogen activated protein kinase family (MAPK) was significantly altered in the presence of PACs, leading to decreased transcription of genes in the nucleus and decreased tumor cell growth. Quantitative (Q)-PCR was used to confirm microarray data showing gene expression changes in some key apoptotic pathways. Western blotting was used to confirm the up- regulation or down-regulation of key proteins involved in the MAPK pathway. Significant changes in p53, APAF and VEGF protein expression were seen as early as eighteen hours. Flow cytometry was employed to identify changes in the cell cycle due to exposure to PACs. HCT116 and HT29 colon cancer cells showed a significant change in granularity and a significant increase in G2 arrest compared to control when exposed to PACs for as little as six hours. This study has provided insight into mechanisms by which cranberry PACs may inhibit colon cancer

Cranberry Fruit and Leaf Polyphenols Inhibit Staphylococcus Bacterial Biofilms

Cranberry (Vaccinium macrocarpon) is known for urinary tract health benefits associated with reducing the adhesion of E. coli bacteria. This property has been linked to cranberry polyphenols known as proanthocyanidins. Staphylococcus bacteria are a growing public health concern due to development of resistant strains. Identification of agents that inhibit biofilm formation by these bacteria may provide a new route to reduce infection in clinical settings. Fruit and leaves of North American cranberry (Vaccinium macrocarpon) and cranberry juice were fractionated and screened for their ability to prevent biofilm formation by several strains of S. aureus and S. epidermidis bacteria. MALDI-TOF MS analysis of the most bioactive fractions identified the major constituents as proanthocyanidin oligomers (PACs) with A-type linkages, ranging in size from 2-12 degrees of polymerization. Further characterization by NMR is underway. The polyphenol-rich fractions from cranberry leaf, fruit and juice inhibited biofilm formation by strains of S. aureus and S. epidermidis, with MBIC as low as 3.1 μg/mL, and without significant bacteriocidal activity. Thus, compounds from cranberry fruit, plant material and juice may be useful in reducing Staphylococcus biofilms without promoting resistance

Rat retina shows robust circadian expression of clock and clock output genes in explant culture.

PURPOSE: Circadian rhythms are central to vision and retinal physiology. A circadian clock located within the retina controls various rhythmic processes including melatonin synthesis in photoreceptors. In the present study, we evaluated the rhythmic expression of clock genes and clock output genes in retinal explants maintained for several days in darkness. METHODS: Retinas were dissected from Wistar rats, either wild-type or from the Per1-luciferase transgenic line housed under a daily 12 h:12 h light-dark cycle (LD12/12), and put in culture at zeitgeber time (ZT) 12 on semipermeable membranes. Explants from wild-type rats were collected every 4 h over 3 days, and total RNA was extracted, quantified, and reverse transcribed. Gene expression was assessed with quantitative PCR, and the periodicity of the relative mRNA amounts was assessed with nonlinear least squares fitting to sine wave functions. Bioluminescence in explants from Per1-luciferase rats was monitored for several days under three different culture protocols. RESULTS: Rhythmic expression was found for all studied clock genes and for clock downstream targets such as c-fos and arylalkylamine N-acetyltransferase (Aanat) genes. Clock and output genes cycled with relatively similar periods and acrophases (peaks of expression during subjective night, except c-fos, which peaked around the end of the subjective day). Data for Per1 were confirmed with bioluminescence monitoring, which also permitted culture conditions to be optimized to study the retina clock. CONCLUSIONS: Our work shows the free-running expression profile of multiple clock genes and potential clock targets in mammalian retinal explants. This research further strengthens the notion that the retina contains a self-sustained oscillator that can be functionally characterized in organotypic culture.journal articleresearch support, non-u.s. gov't20142014 06 02importe

Pan-cancer Alterations of the MYC Oncogene and Its Proximal Network across the Cancer Genome Atlas

Although theMYConcogene has been implicated incancer, a systematic assessment of alterations ofMYC, related transcription factors, and co-regulatoryproteins, forming the proximal MYC network (PMN),across human cancers is lacking. Using computa-tional approaches, we define genomic and proteo-mic features associated with MYC and the PMNacross the 33 cancers of The Cancer Genome Atlas.Pan-cancer, 28% of all samples had at least one ofthe MYC paralogs amplified. In contrast, the MYCantagonists MGA and MNT were the most frequentlymutated or deleted members, proposing a roleas tumor suppressors.MYCalterations were mutu-ally exclusive withPIK3CA,PTEN,APC,orBRAFalterations, suggesting that MYC is a distinct onco-genic driver. Expression analysis revealed MYC-associated pathways in tumor subtypes, such asimmune response and growth factor signaling; chro-matin, translation, and DNA replication/repair wereconserved pan-cancer. This analysis reveals insightsinto MYC biology and is a reference for biomarkersand therapeutics for cancers with alterations ofMYC or the PMN

Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context

Long noncoding RNAs (lncRNAs) are commonly dys-regulated in tumors, but only a handful are known toplay pathophysiological roles in cancer. We inferredlncRNAs that dysregulate cancer pathways, onco-genes, and tumor suppressors (cancer genes) bymodeling their effects on the activity of transcriptionfactors, RNA-binding proteins, and microRNAs in5,185 TCGA tumors and 1,019 ENCODE assays.Our predictions included hundreds of candidateonco- and tumor-suppressor lncRNAs (cancerlncRNAs) whose somatic alterations account for thedysregulation of dozens of cancer genes and path-ways in each of 14 tumor contexts. To demonstrateproof of concept, we showed that perturbations tar-geting OIP5-AS1 (an inferred tumor suppressor) andTUG1 and WT1-AS (inferred onco-lncRNAs) dysre-gulated cancer genes and altered proliferation ofbreast and gynecologic cancer cells. Our analysis in-dicates that, although most lncRNAs are dysregu-lated in a tumor-specific manner, some, includingOIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergis-tically dysregulate cancer pathways in multiple tumorcontexts

Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas

This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin

Spatial Organization and Molecular Correlation of Tumor-Infiltrating Lymphocytes Using Deep Learning on Pathology Images

Beyond sample curation and basic pathologic characterization, the digitized H&E-stained images of TCGA samples remain underutilized. To highlight this resource, we present mappings of tumorinfiltrating lymphocytes (TILs) based on H&E images from 13 TCGA tumor types. These TIL maps are derived through computational staining using a convolutional neural network trained to classify patches of images. Affinity propagation revealed local spatial structure in TIL patterns and correlation with overall survival. TIL map structural patterns were grouped using standard histopathological parameters. These patterns are enriched in particular T cell subpopulations derived from molecular measures. TIL densities and spatial structure were differentially enriched among tumor types, immune subtypes, and tumor molecular subtypes, implying that spatial infiltrate state could reflect particular tumor cell aberration states. Obtaining spatial lymphocytic patterns linked to the rich genomic characterization of TCGA samples demonstrates one use for the TCGA image archives with insights into the tumor-immune microenvironment

CD133, CD15/SSEA-1, CD34 or side populations do not resume tumor-initiating properties of long-term cultured cancer stem cells from human malignant glio-neuronal tumors

<p>Abstract</p> <p>Background</p> <p>Tumor initiating cells (TICs) provide a new paradigm for developing original therapeutic strategies.</p> <p>Methods</p> <p>We screened for TICs in 47 human adult brain malignant tumors. Cells forming floating spheres in culture, and endowed with all of the features expected from tumor cells with stem-like properties were obtained from glioblastomas, medulloblastoma but not oligodendrogliomas.</p> <p>Results</p> <p>A long-term self-renewal capacity was particularly observed for cells of malignant glio-neuronal tumors (MGNTs). Cell sorting, karyotyping and proteomic analysis demonstrated cell stability throughout prolonged passages. Xenografts of fewer than 500 cells in Nude mouse brains induced a progressively growing tumor. CD133, CD15/LeX/Ssea-1, CD34 expressions, or exclusion of Hoechst dye occurred in subsets of cells forming spheres, but was not predictive of their capacity to form secondary spheres or tumors, or to resist high doses of temozolomide.</p> <p>Conclusions</p> <p>Our results further highlight the specificity of a subset of high-grade gliomas, MGNT. TICs derived from these tumors represent a new tool to screen for innovative therapies.</p