755 research outputs found
BlackOPs: Increasing confidence in variant detection through mappability filtering
Identifying variants using high-throughput sequen-cing data is currently a challenge because true biological variants can be indistinguishable from technical artifacts. One source of technical arti-fact results from incorrectly aligning experimen-tally observed sequences to their true genomic origin (âmismappingâ) and inferring differences in mismapped sequences to be true variants. We de-veloped BlackOPs, an open-source tool that simu-lates experimental RNA-seq and DNA whole exome sequences derived from the reference genome, aligns these sequences by custom parameters, detects variants and outputs a blacklist of positions and alleles caused by mismapping. Blacklist
Site-specific inductive and inhibitory activities of MMP-2 and MMP-3 orchestrate mammary gland branching morphogenesis
During puberty, mouse mammary epithelial ducts invade the stromal mammary fat pad in a wave of branching morphogenesis to form a complex ductal tree. Using pharmacologic and genetic approaches, we find that mammary gland branching morphogenesis requires transient matrix metalloproteinase (MMP) activity for invasion and branch point selection. MMP-2, but not MMP-9, facilitates terminal end bud invasion by inhibiting epithelial cell apoptosis at the start of puberty. Unexpectedly, MMP-2 also represses precocious lateral branching during mid-puberty. In contrast, MMP-3 induces secondary and tertiary lateral branching of ducts during mid-puberty and early pregnancy. Nevertheless, the mammary gland is able to develop lactational competence in MMP mutant mice. Thus, specific MMPs refine the mammary branching pattern by distinct mechanisms during mammary gland branching morphogenesis
Orthotopic Ileal Neobladder Reconstruction for Bladder Cancer: Is Adjuvant Chemotherapy Safe?
ABSTRACT Objective: We examined our database of patients undergoing radical cystectomy (RC) with orthotopic neobladder (NB) to determine whether adjuvant chemotherapy in this group is safe. Materials and Methods: We performed a retrospective analysis of patients who underwent radical cystectomy and urinary diversion between 1992 and 2004. Relevant clinical and therapeutic data were entered into a database. High-risk bladder cancer patients who underwent NB were identified. They were stratified into 2 groups, those who received adjuvant chemotherapy and those who did not. The incidence of complications between the 2 groups was analyzed and compared. Results: Over the 12-year period, 136 patients underwent RC and NB construction for bladder cancer. Of these, 83 patients were at high risk for recurrence. Nineteen patients received adjuvant chemotherapy and 64 did not. The complication rate in the adjuvant chemotherapy group was 53% and it was 23% in those who did not receive chemotherapy. There were no perioperative or treatment related death. There were 2 patients with grade 4 toxicity in the adjuvant chemotherapy group. There was a statistical difference between these two groups with regard to the incidence of complications. However, none of these complications was life-threatening, required only conservative treatment and caused no long-term disability. Conclusions: Adjuvant chemotherapy is a safe treatment for patients undergoing RC and NB substitution. Hence, the option of orthotopic NB should not be denied in selected bladder cancer patients with high risk for recurrent disease
Percentage of the positive area of bone metastasis is an independent predictor of disease death in advanced prostate cancer
Integrated analysis of RNA and DNA from the phase III trial CALGB 40601 identifies predictors of response to trastuzumab-based neoadjuvant chemotherapy in HER2-positive breast cancer
Purpose: Response to a complex trastuzumab-based regimen is affected by multiple features of the tumor and its microenvironment. Developing a predictive algorithm is key to optimizing HER2-targeting therapy. Experimental Design: We analyzed 137 pretreatment tumors with mRNA-seq and DNA exome sequencing from CALGB 40601, a neoadjuvant phase III trial of paclitaxel plus trastuzumab with or without lapatinib in stage II to III HER2-positive breast cancer. We adopted an Elastic Net regularized regression approach that controls for covarying features within high-dimensional data. First, we applied 517 known gene expression signatures to develop an Elastic Net model to predict pCR, which we validated on 143 samples from four independent trials. Next, we performed integrative analyses incorporating clinicopathologic information with somatic mutation status, DNA copy number alterations (CNA), and gene signatures. Results: The Elastic Net model using only gene signatures predicted pCR in the validation sets (AUC Âź 0.76). Integrative analyses showed that models containing gene signatures, clinical features, and DNA information were better pCR predictors than models containing a single data type. Frequently selected variables from the multiplatform models included amplifications of chromosome 6p, TP53 mutation, HER2-enriched subtype, and immune signatures. Variables predicting resistance included Luminal/ERĂž features. Conclusions: Models using RNA only, as well as integrated RNA and DNA models, can predict pCR with improved accuracy over clinical variables. Somatic DNA alterations (mutation, CNAs), tumor molecular subtype (HER2E, Luminal), and the microenvironment (immune cells) were independent predictors of response to trastuzumab and paclitaxel-based regimens. This highlights the complexity of predicting response in HER2-positive breast cancer
Using Simulations as a Starting Point for Constructing Meaningful Learning Games
For many school administrators and decision makers, the term âvideo gamesâ holds numerous cultural associations which make their adoption in the education space challenging. Additionally, the term is so broad that it can sometimes be difficult to communicate explicitly a desire to build learning experiences that go beyond the Drill and Kill edutainment titles that currently dominate most peopleâs perceptions of educational games. By contrast, the term âsimulationsâ is often well respected among educators, particularly in the natural sciences. With âsimulationâ already being a full genre of video games, it would seem natural that researchers are beginning to explore the overlaps between simulation games and pedagogical goals that go beyond those found in Drill and Kill games. In this chapter, we survey some of the relevant research concerning both simulations and video games and outline practical pathways through which we can leverage the interest and frameworks designed for simulation construction to facilitate the introduction of video game concepts and experiences into the classroom environment. In particular, we report on the use of Starlogo TNG, a graphical programming environment in which kids themselves can create simulation-based video games, for deepening childrenâs understanding of scientific concepts
An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics
For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types
BlackOPs: increasing confidence in variant detection through mappability filtering
Identifying variants using high-throughput sequencing data is currently a challenge because true biological variants can be indistinguishable from technical artifacts. One source of technical artifact results from incorrectly aligning experimentally observed sequences to their true genomic origin (âmismappingâ) and inferring differences in mismapped sequences to be true variants. We developed BlackOPs, an open-source tool that simulates experimental RNA-seq and DNA whole exome sequences derived from the reference genome, aligns these sequences by custom parameters, detects variants and outputs a blacklist of positions and alleles caused by mismapping. Blacklists contain thousands of artifact variants that are indistinguishable from true variants and, for a given sample, are expected to be almost completely false positives. We show that these blacklist positions are specific to the alignment algorithm and read length used, and BlackOPs allows users to generate a blacklist specific to their experimental setup. We queried the dbSNP and COSMIC variant databases and found numerous variants indistinguishable from mapping errors. We demonstrate how filtering against blacklist positions reduces the number of potential false variants using an RNA-seq glioblastoma cell line data set. In summary, accounting for mapping-caused variants tuned to experimental setups reduces false positives and, therefore, improves genome characterization by high-throughput sequencing
Efficacy of pegylated interferon plus ribavirin in combination with corticosteroid for two cases of combined hepatitis C and autoimmune hepatitis
The treatment strategy for cases of combined autoimmune hepatitis (AIH) and chronic hepatitis C (CHC) has not yet been established. A 47-year-old woman and a 53-year-old-woman were hospitalized for treatment of CHC. Ultrasonography and histological findings revealed that their liver was not cirrhotic but did have chronic damage. The histological findings of both patients were suggestive of AIH. The patients were systematically treated with pegylated interferon-alpha 2b plus ribavirin which was preceded by and combined with corticosteroid (CS), and showed sustained virological responses and normal liver function. Although these two patients with combined AIH and CHC were successfully treated with this regimen, careful attention to exacerbation of hepatic inflammation is needed because hepatitis C viral load was increased due to immunosuppression during CS treatment
Thiothymidine combined with UVA as a potential novel therapy for bladder cancer
BACKGROUND: Thiothymidine (S4TdR) can be incorporated into DNA and sensitise cells to DNA damage and cell death following exposure to UVA light. Studies were performed to determine if the combination of S4TdR and UVA could be an effective treatmentfor bladder cancer.
METHODS: Uptake and incorporation of S4TdR was determined in rat and human bladder tumour cell lines. Measures of DNA crosslinking and apoptosis were also performed. In vivo activity of the combination of S4TdR and UVA was investigated in an orthotopic model of bladder cancer in rats.
RESULTS: Thiothymidine (200 uM) replaced up to 0.63% of thymidine in rat and tumour bladder cancer cells. The combination of S4TdR (10â200 uM) and UVA (1â5 kJm-2) caused apoptosis and cell death at doses that were not toxic alone. Addition of raltitrexed (Astra Zeneca, Alderley Edge, Cheshire, UK) increased the incorporation of S4TdR into DNA (up to 20-fold at IC5) and further sensitised cells to UVA. Cytotoxic effect was associated with crosslinking of DNA, at least partially to protein. Intravenous administration of S4TdR, in combination with UVA delivered directly to the bladder, resulted in an antitumour effect in three of five animals treated.
CONCLUSION: These data indicate that the combination of S4TdR and UVA has potential as a treatment for bladder cancer, and give some insight into the mechanism of action. Further work is necessary to optimise the delivery of the two components
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