Search tips
Search criteria

Results 1-7 (7)

Clipboard (0)
Year of Publication
Document Types
1.  Papillary Carcinoma of the Breast: An Overview 
Papillary carcinoma of the breast represents approximately 0.5% of all newly diagnosed cases of breast cancer. The prevalence of both invasive and in situ papillary carcinoma seems to be greater older postmenopausal women, and -in relative terms-in males. Histologic features of the tumor include cellular proliferations surrounding fibrovascular cores, with or without invasion. In this review, characteristics of both in situ and invasive disease are outlined. Immunohistochemical analyses of papillary carcinoma suggest the utility of markers such as smooth muscle myosin heavy chain, calponin, p63 and high molecular weight keratins, which can characterize the myoepithelial cell layer. With respect to radiographic evaluation of papillary carcinoma, ultrasonography is the most extensively studied imaging modality, though magnetic resonance mammography has potential utility. Available data suggest improved outcome for papillary carcinoma as compared to invasive ductal carcinoma. Treatment-related information for patients with papillary carcinoma is limited, and patterns noted in available series suggest a variable approach to this disease. The scarcity of information underscores the need for further treatment- and outcome-related studies in papillary carcinoma of the breast.
PMCID: PMC3244819  PMID: 20524058
papillary; breast carcinoma; male breast cancer; breast ultrasonography; breast magnetic resonance mammography
2.  MPromDb update 2010: an integrated resource for annotation and visualization of mammalian gene promoters and ChIP-seq experimental data 
Nucleic Acids Research  2010;39(Database issue):D92-D97.
MPromDb (Mammalian Promoter Database) is a curated database that strives to annotate gene promoters identified from ChIP-seq results with the goal of providing an integrated resource for mammalian transcriptional regulation and epigenetics. We analyzed 507 million uniquely aligned RNAP-II ChIP-seq reads from 26 different data sets that include six human cell-types and 10 distinct mouse cell/tissues. The updated MPromDb version consists of computationally predicted (novel) and known active RNAP-II promoters (42 893 human and 48 366 mouse promoters) from various data sets freely available at NCBI GEO database. We found that 36% and 40% of protein-coding genes have alternative promoters in human and mouse genomes and ∼40% of promoters are tissue/cell specific. The identified RNAP-II promoters were annotated using various known and novel gene models. Additionally, for novel promoters we looked into other evidences—GenBank mRNAs, spliced ESTs, CAGE promoter tags and mRNA-seq reads. Users can search the database based on gene id/symbol, or by specific tissue/cell type and filter results based on any combination of tissue/cell specificity, Known/Novel, CpG/NonCpG, and protein-coding/non-coding gene promoters. We have also integrated GBrowse genome browser with MPromDb for visualization of ChIP-seq profiles and to display the annotations. The current release of MPromDb can be accessed at
PMCID: PMC3013732  PMID: 21097880
3.  The H3K27me3 Demethylase dUTX Is a Suppressor of Notch- and Rb-Dependent Tumors in Drosophila▿  
Molecular and Cellular Biology  2010;30(10):2485-2497.
Trimethylated lysine 27 of histone H3 (H3K27me3) is an epigenetic mark for gene silencing and can be demethylated by the JmjC domain of UTX. Excessive H3K27me3 levels can cause tumorigenesis, but little is known about the mechanisms leading to those cancers. Mutants of the Drosophila H3K27me3 demethylase dUTX display some characteristics of Trithorax group mutants and have increased H3K27me3 levels in vivo. Surprisingly, dUTX mutations also affect H3K4me1 levels in a JmjC-independent manner. We show that a disruption of the JmjC domain of dUTX results in a growth advantage for mutant cells over adjacent wild-type tissue due to increased proliferation. The growth advantage of dUTX mutant tissue is caused, at least in part, by increased Notch activity, demonstrating that dUTX is a Notch antagonist. Furthermore, the inactivation of Retinoblastoma (Rbf in Drosophila) contributes to the growth advantage of dUTX mutant tissue. The excessive activation of Notch in dUTX mutant cells leads to tumor-like growth in an Rbf-dependent manner. In summary, these data suggest that dUTX is a suppressor of Notch- and Rbf-dependent tumors in Drosophila melanogaster and may provide a model for UTX-dependent tumorigenesis in humans.
PMCID: PMC2863695  PMID: 20212086
4.  Genome-wide mapping of RNA Pol-II promoter usage in mouse tissues by ChIP-seq 
Nucleic Acids Research  2010;39(1):190-201.
Alternative promoters that are differentially used in various cellular contexts and tissue types add to the transcriptional complexity in mammalian genome. Identification of alternative promoters and the annotation of their activity in different tissues is one of the major challenges in understanding the transcriptional regulation of the mammalian genes and their isoforms. To determine the use of alternative promoters in different tissues, we performed ChIP-seq experiments using antibody against RNA Pol-II, in five adult mouse tissues (brain, liver, lung, spleen and kidney). Our analysis identified 38 639 Pol-II promoters, including 12 270 novel promoters, for both protein coding and non-coding mouse genes. Of these, 6384 promoters are tissue specific which are CpG poor and we find that only 34% of the novel promoters are located in CpG-rich regions, suggesting that novel promoters are mostly tissue specific. By identifying the Pol-II bound promoter(s) of each annotated gene in a given tissue, we found that 37% of the protein coding genes use alternative promoters in the five mouse tissues. The promoter annotations and ChIP-seq data presented here will aid ongoing efforts of characterizing gene regulatory regions in mammalian genomes.
PMCID: PMC3017616  PMID: 20843783
5.  Identification of scaffold/Matrix Attachment (S/MAR) like DNA element from the gastrointestinal protozoan parasite Giardia lamblia 
BMC Genomics  2010;11:386.
Chromatin in the nucleus of all eukaryotes is organized into a system of loops and domains. These loops remain fastened at their bases to the fundamental framework of the nucleus, the matrix or the scaffold. The DNA sequences which anchor the bases of the chromatin loops to the matrix are known as Scaffold/Matrix Attachment Regions or S/MARs. Though S/MARs have been studied in yeast and higher eukaryotes and they have been found to be associated with gene organization and regulation of gene expression, they have not been reported in protists like Giardia. Several tools have been discovered and formulated to predict S/MARs from a genome of a higher eukaryote which take into account a number of features. However, the lack of a definitive consensus sequence in S/MARs and the randomness of the protozoan genome in general, make it a challenge to predict and identify such sequences from protists.
Here, we have analysed the Giardia genome for the probable S/MARs predicted by the available computational tools; and then shown these sequences to be physically associated with the nuclear matrix. Our study also reflects that while no single computational tool is competent to predict such complex elements from protist genomes, a combination of tools followed by experimental verification is the only way to confirm the presence of these elements from these organisms.
This is the first report of S/MAR elements from the protozoan parasite Giardia lamblia. This initial work is expected to lay a framework for future studies relating to genome organization as well as gene regulatory elements in this parasite.
PMCID: PMC3017767  PMID: 20565887
6.  Non-union scaphoid: Four-corner fusion of the wrist 
Indian Journal of Orthopaedics  2010;44(2):208-211.
Four-corner fusion of the wrist is an option for management of non-union scaphoid with painful arthritis of the wrist. Various surgical techniques have been devised for four-corner fusion, with inconsistent results. We present our experience of four-corner fusion achieved using a standard H-plate, designed originally for anterior cervical plating.
Materials and Methods:
The study is a retrospective analysis of six cases of painful wrist arthritis resulting from nonunion of scaphoid treated by four-corner fusion, between 1996 and 2004. The average duration of follow-up was 5.8 years. Each patient was evaluated clinically according to the rating scales described by Bach.
The mean grip-strength calculated as a percentage of the uninvolved side was 47% pre-operatively, and 74% post- operatively at the final follow-up. The difference between the preoperative and postoperative ‘pain ratings’ and ‘activity ratings’ was found to be statistically significant (P<0.001). Mean time to fusion was 16.1 weeks. Dorsal impingement was the most common associated problem.
H-plate, used for four-corner fusion, provides rigid fixation, ensures fusion, and is a good alternative to the available options.
PMCID: PMC2856398  PMID: 20419010
Four corner fusion; Cervical H-plate; nonunion scaphoid
7.  Annotation of gene promoters by integrative data-mining of ChIP-seq Pol-II enrichment data 
BMC Bioinformatics  2010;11(Suppl 1):S65.
Use of alternative gene promoters that drive widespread cell-type, tissue-type or developmental gene regulation in mammalian genomes is a common phenomenon. Chromatin immunoprecipitation methods coupled with DNA microarray (ChIP-chip) or massive parallel sequencing (ChIP-seq) are enabling genome-wide identification of active promoters in different cellular conditions using antibodies against Pol-II. However, these methods produce enrichment not only near the gene promoters but also inside the genes and other genomic regions due to the non-specificity of the antibodies used in ChIP. Further, the use of these methods is limited by their high cost and strong dependence on cellular type and context.
We trained and tested different state-of-art ensemble and meta classification methods for identification of Pol-II enriched promoter and Pol-II enriched non-promoter sequences, each of length 500 bp. The classification models were trained and tested on a bench-mark dataset, using a set of 39 different feature variables that are based on chromatin modification signatures and various DNA sequence features. The best performing model was applied on seven published ChIP-seq Pol-II datasets to provide genome wide annotation of mouse gene promoters.
We present a novel algorithm based on supervised learning methods to discriminate promoter associated Pol-II enrichment from enrichment elsewhere in the genome in ChIP-chip/seq profiles. We accumulated a dataset of 11,773 promoter and 46,167 non-promoter sequences, each of length 500 bp, generated from RNA Pol-II ChIP-seq data of five tissues (Brain, Kidney, Liver, Lung and Spleen). We evaluated the classification models in building the best predictor and found that Bagging and Random Forest based approaches give the best accuracy. We implemented the algorithm on seven different published ChIP-seq datasets to provide a comprehensive set of promoter annotations for both protein-coding and non-coding genes in the mouse genome. The resulting annotations contain 13,413 (4,747) protein-coding (non-coding) genes with single promoters and 9,929 (1,858) protein-coding (non-coding) genes with two or more alternative promoters, and a significant number of unassigned novel promoters.
Our new algorithm can successfully predict the promoters from the genome wide profile of Pol-II bound regions. In addition, our algorithm performs significantly better than existing promoter prediction methods and can be applied for genome-wide predictions of Pol-II promoters.
PMCID: PMC3009539  PMID: 20122241

Results 1-7 (7)