13 research outputs found
Tumor Microvessel Density as a Prognostic Marker in High-Risk Renal Cell Carcinoma Patients Treated on ECOG-ACRIN E2805
PurposeâIncreased vascularity is a hallmark of renal cell carcinoma (RCC). Microvessel density (MVD) is one measurement of tumor angiogenesis; however, its utility as a biomarker of outcome is unknown. ECOG-ACRIN 2805 (E2805) enrolled 1,943 resected high-risk RCC patients randomized to adjuvant sunitinib, sorafenib, or placebo. We aimed to determine the prognostic and predictive role of MVD in RCC.
Experimental DesignâWe obtained pretreatment primary RCC nephrectomy tissues from 822 patients on E2805 and constructed tissue microarrays. Using quantitative immunofluorescence, we measured tumor MVD as the area of CD34-expressing cells. We determined the association with disease-free survival (DFS), overall survival (OS), treatment arm, and clinicopathologic variables.
ResultsâHigh MVD (above the median) was associated with prolonged OS for the entire cohort (p = 0.021) and for patients treated with placebo (p = 0.028). The association between high MVD and OS was weaker in patients treated with sunitinib or sorafenib (p = 0.060). MVD was not associated with DFS (p = 1.00). On multivariable analysis, MVD remained independently associated with improved OS (p = 0.013). High MVD correlated with Fuhrman grade 1â2 (p \u3c 0.001), clear cell histology (p \u3c 0.001), and absence of necrosis (p \u3c 0.001) but not with gender, age, sarcomatoid features, lymphovascular invasion, or tumor size.
ConclusionsâHigh MVD in resected high-risk RCC patients is an independent prognostic, rather than predictive, biomarker of improved OS. Further studies should assess whether incorporating MVD into clinical models will enhance our ability to predict outcome and if low MVD can be used for selection of high-risk patients for adjuvant therapy trials
Mutations of RNA polymerase II activate key genes of the nucleoside triphosphate biosynthetic pathways
The yeast URA2 gene, encoding the rate-limiting enzyme of UTP biosynthesis, is transcriptionally activated by UTP shortage. In contrast to other genes of the UTP pathway, this activation is not governed by the Ppr1 activator. Moreover, it is not due to an increased recruitment of RNA polymerase II at the URA2 promoter, but to its much more effective progression beyond the URA2 mRNA start site(s). Regulatory mutants constitutively expressing URA2 resulted from cis-acting deletions upstream of the transcription initiator region, or from amino-acid replacements altering the RNA polymerase II Switch 1 loop domain, such as rpb1-L1397S. These two mutation classes allowed RNA polymerase to progress downstream of the URA2 mRNA start site(s). rpb1-L1397S had similar effects on IMD2 (IMP dehydrogenase) and URA8 (CTP synthase), and thus specifically activated the rate-limiting steps of UTP, GTP and CTP biosynthesis. These data suggest that the Switch 1 loop of RNA polymerase II, located at the downstream end of the transcription bubble, may operate as a specific sensor of the nucleoside triphosphates available for transcription
Evolutionary Dynamics of the Ty3/Gypsy LTR Retrotransposons in the Genome of Anopheles gambiae
Ty3/gypsy elements represent one of the most abundant and diverse LTR-retrotransposon (LTRr) groups in the Anopheles gambiae genome, but their evolutionary dynamics have not been explored in detail. Here, we conduct an in silico analysis of the distribution and abundance of the full complement of 1045 copies in the updated AgamP3 assembly. Chromosomal distribution of Ty3/gypsy elements is inversely related to arm length, with densities being greatest on the X, and greater on the short versus long arms of both autosomes. Taking into account the different heterochromatic and euchromatic compartments of the genome, our data suggest that the relative abundance of Ty3/gypsy LTRrs along each chromosome arm is determined mainly by the different proportions of heterochromatin, particularly pericentric heterochromatin, relative to total arm length. Additionally, the breakpoint regions of chromosomal inversion 2La appears to be a haven for LTRrs. These elements are underrepresented more than 7-fold in euchromatin, where 33% of the Ty3/gypsy copies are associated with genes. The euchromatin on chromosome 3R shows a faster turnover rate of Ty3/gypsy elements, characterized by a deficit of proviral sequences and the lowest average sequence divergence of any autosomal region analyzed in this study. This probably reflects a principal role of purifying selection against insertion for the preservation of longer conserved syntenyc blocks with adaptive importance located in 3R. Although some Ty3/gypsy LTRrs show evidence of recent activity, an important fraction are inactive remnants of relatively ancient insertions apparently subject to genetic drift. Consistent with these computational predictions, an analysis of the occupancy rate of putatively older insertions in natural populations suggested that the degenerate copies have been fixed across the species range in this mosquito, and also are shared with the sibling species Anopheles arabiensis
Integration of EPI and pediatric HIV services for improved ART initiation in Zimbabwe
These data and .do files are associated with the paper âIntegration of EPI and paediatric HIV services for improved ART initiationâ by Marta Prescott, Caroline Boeke, Tendai Gotora, Haurovi William Mafaune, Wadzanai Motsi, Justin Graves, Alexio Mangwiro, Elizabeth McCarthy. They were funded under the International Initiative for Impact Evaluationâs Thematic Window 7 (TW7). They include outcomes of interest, socio-demographic variables, and other variables necessary to replicate the study
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The KRAS-variant and miRNA expression in RTOG endometrial cancer clinical trials 9708 and 9905.
ObjectiveTo explore the association of a functional germline variant in the 3'-UTR of KRAS with endometrial cancer risk, as well as the association of microRNA (miRNA) signatures and the KRAS-variant with clinical characteristics and survival outcomes in two prospective RTOG endometrial cancer trials.Methods/materialsThe association of the KRAS-variant with endometrial cancer risk was evaluated by case-control analysis of 467 women with type 1 or 2 endometrial cancer and 582 age-matched controls. miRNA and DNA were isolated for expression profiling and genotyping from tumor specimens of 46 women with type 1 endometrial cancer enrolled in RTOG trials 9708 and 9905. miRNA expression levels and KRAS-variant genotype were correlated with patient and tumor characteristics, and survival outcomes were evaluated by variant allele type.ResultsThe KRAS-variant was not significantly associated with overall endometrial cancer risk (14% controls and 17% type 1 cancers), although was enriched in type 2 endometrial cancers (24%, pâ=â0.2). In the combined analysis of RTOG 9708/9905, miRNA expression differed by age, presence of lymphovascular invasion and KRAS-variant status. Overall survival rates at 3 years for patients with the variant and wild-type alleles were 100% and 77% (HR 0.3, pâ=â0.24), respectively, favoring the variant.ConclusionsThe KRAS-variant may be a genetic marker of risk for type 2 endometrial cancers. In addition, tumor miRNA expression appears to be associated with patient age, lymphovascular invasion and the KRAS-variant, supporting the hypothesis that altered tumor biology can be measured by miRNA expression, and that the KRAS-variant likely impacts endometrial tumor biology
The <i>KRAS-</i>Variant and miRNA Expression in RTOG Endometrial Cancer Clinical Trials 9708 and 9905
<div><p>Objective</p><p>To explore the association of a functional germline variant in the 3âČ-UTR of <i>KRAS</i> with endometrial cancer risk, as well as the association of microRNA (miRNA) signatures and the <i>KRAS</i>-variant with clinical characteristics and survival outcomes in two prospective RTOG endometrial cancer trials.</p><p>Methods/Materials</p><p>The association of the <i>KRAS</i>-variant with endometrial cancer risk was evaluated by case-control analysis of 467 women with type 1 or 2 endometrial cancer and 582 age-matched controls. miRNA and DNA were isolated for expression profiling and genotyping from tumor specimens of 46 women with type 1 endometrial cancer enrolled in RTOG trials 9708 and 9905. miRNA expression levels and <i>KRAS-</i>variant genotype were correlated with patient and tumor characteristics, and survival outcomes were evaluated by variant allele type.</p><p>Results</p><p>The <i>KRAS</i>-variant was not significantly associated with overall endometrial cancer risk (14% controls and 17% type 1 cancers), although was enriched in type 2 endometrial cancers (24%, pâ=â0.2). In the combined analysis of RTOG 9708/9905, miRNA expression differed by age, presence of lymphovascular invasion and <i>KRAS</i>-variant status. Overall survival rates at 3 years for patients with the variant and wild-type alleles were 100% and 77% (HR 0.3, pâ=â0.24), respectively, favoring the variant.</p><p>Conclusions</p><p>The <i>KRAS-</i>variant may be a genetic marker of risk for type 2 endometrial cancers. In addition, tumor miRNA expression appears to be associated with patient age, lymphovascular invasion and the <i>KRAS-</i>variant, supporting the hypothesis that altered tumor biology can be measured by miRNA expression, and that the <i>KRAS-</i>variant likely impacts endometrial tumor biology.</p></div
MiRNA signatures differ in tumors with lymphovascular invasion (LVI).
<p>Yellow represents patients with LVI, and blue represents patients without LVI.</p
miRNA expression in <i>KRAS-</i>variant negative versus positive tumors.
<p>Key: logFCâ=âlog fold change; m.e.â=âmean expression.</p
Clinical and pathologic characteristics of 46 patients with allele data from RTOG trials 9708 and 9905.
<p>Key: minâ=âminimum; maxâ=âmaximum; ECOG scoreâ=âEastern Cooperative Oncology Group performance status score; FIGOâ=âInternational Federation of Gynecology and Obstetrics; MMIâ=âmyometrial invasion; LVIâ=âlymphovascular invasion.</p