Discovery of a Distinct Superfamily of Kunitz-Type Toxin (KTT) from Tarantulas

BACKGROUND: Kuntiz-type toxins (KTTs) have been found in the venom of animals such as snake, cone snail and sea anemone. The main ancestral function of Kunitz-type proteins was the inhibition of a diverse array of serine proteases, while toxic activities (such as ion-channel blocking) were developed under a variety of Darwinian selection pressures. How new functions were grafted onto an old protein scaffold and what effect Darwinian selection pressures had on KTT evolution remains a puzzle. PRINCIPAL FINDINGS: Here we report the presence of a new superfamily of ktts in spiders (TARANTULAS: Ornithoctonus huwena and Ornithoctonus hainana), which share low sequence similarity to known KTTs and is clustered in a distinct clade in the phylogenetic tree of KTT evolution. The representative molecule of spider KTTs, HWTX-XI, purified from the venom of O. huwena, is a bi-functional protein which is a very potent trypsin inhibitor (about 30-fold more strong than BPTI) as well as a weak Kv1.1 potassium channel blocker. Structural analysis of HWTX-XI in 3-D by NMR together with comparative function analysis of 18 expressed mutants of this toxin revealed two separate sites, corresponding to these two activities, located on the two ends of the cone-shape molecule of HWTX-XI. Comparison of non-synonymous/synonymous mutation ratios (omega) for each site in spider and snake KTTs, as well as PBTI like body Kunitz proteins revealed high Darwinian selection pressure on the binding sites for Kv channels and serine proteases in snake, while only on the proteases in spider and none detected in body proteins, suggesting different rates and patterns of evolution among them. The results also revealed a series of key events in the history of spider KTT evolution, including the formation of a novel KTT family (named sub-Kuntiz-type toxins) derived from the ancestral native KTTs with the loss of the second disulfide bridge accompanied by several dramatic sequence modifications. CONCLUSIONS/SIGNIFICANCE: These finding illustrate that the two activity sites of Kunitz-type toxins are functionally and evolutionally independent and provide new insights into effects of Darwinian selection pressures on KTT evolution, and mechanisms by which new functions can be grafted onto old protein scaffolds

Social Networking Technology, Social Network Composition, and Reductions in Substance Use Among Homeless Adolescents

Peer-based prevention programs for homeless youth are complicated by the potential for reinforcing high-risk behaviors among participants. The goal of this study is to understand how homeless youth could be linked to positive peers in prevention programming by understanding where in social and physical space positive peers for homeless youth are located, how these ties are associated with substance use, and the role of social networking technologies (e.g., internet and cell phones) in this process. Personal social network data were collected from 136 homeless adolescents in Los Angeles, CA. Respondents reported on composition of their social networks with respect to: home-based peers and parents (accessed via social networking technology; e.g., the internet, cell phone, texting), homeless peers and agency staff (accessed face-to-face) and whether or not network members were substance-using or non-substance-using. Associations between respondent’s lifetime cocaine, heroin, and methamphetamine use and recent (previous 30 days) alcohol and marijuana use were assessed by the number of non-substance-using versus substance-using ties in multivariate linear regression models. 43% of adolescents reported a non-substance-using home-based tie. More of these ties were associated with less recent alcohol use. 62% of adolescents reported a substance-using homeless tie. More of these ties were associated with more recent marijuana use as well as more lifetime heroin and methamphetamine use. For homeless youth, who are physically disconnected from positive peers, social networking technologies can be used to facilitate the sorts of positive social ties that effective peer-based prevention programs require

Dietary intake of micronutrients and the risk of developing bladder cancer: results from the Belgian case–control study on bladder cancer risk

OBJECTIVE: We aimed to investigate the effect of dietary intake of micronutrients that are metabolized and excreted via the urinary tract on bladder cancer risk. METHODS: A semi-quantitative 322 item food frequency questionnaire (FFQ) was used to collect dietary data from 200 bladder cancer cases and 386 control subjects participating in the Belgian case-control study on bladder cancer risk. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using unconditional logistic regression adjusting for age, sex, smoking characteristics, occupational exposures, and energy intake. RESULTS: We observed a positive association between calcium intake and bladder cancer (OR: 1.77; 95% CI: 1.00-3.15; p-trend = 0.049) and increased odds, although not statistically significant, for highest tertile of phosphorus intake (OR: 1.82; 95% CI: 0.95-3.49; p-trend = 0.06). We identified possible modification of the effects of both calcium and phosphorus by level of magnesium intake. Increased odds of bladder cancer were also observed for participants with highest intake of phosphorus and lowest intake of vitamin D (OR: 4.25; 95% CI: 1.44-12.55) and among older participants with the highest intakes of calcium (OR: 1.90; 95% CI: 1.08-3.36) and phosphorus (OR: 2.02; 95% CI: 1.05-3.92). CONCLUSION: The positive associations we observed between bladder cancer and intake of calcium and phosphorus require confirmation by other studies. The balances between inter-related micronutrients also warrant further examination

Identification of Novel Susceptibility Loci and Genes for Prostate Cancer Risk: A Transcriptome-Wide Association Study in over 140,000 European Descendants

Genome-wide association study–identified prostate cancer risk variants explain only a relatively small fraction of its familial relative risk, and the genes responsible for many of these identified associations remain unknown. To discover novel prostate cancer genetic loci and possible causal genes at previously identified risk loci, we performed a transcriptome-wide association study in 79,194 cases and 61,112 controls of European ancestry. Using data from the Genotype-Tissue Expression Project, we established genetic models to predict gene expression across the transcriptome for both prostate models and cross-tissue models and evaluated model performance using two independent datasets. We identified significant associations for 137 genes at P < 2.61 × 10−6, a Bonferroni-corrected threshold, including nine genes that remained significant at P < 2.61 × 10−6 after adjusting for all known prostate cancer risk variants in nearby regions. Of the 128 remaining associated genes, 94 have not yet been reported as potential target genes at known loci. We silenced 14 genes and many showed a consistent effect on viability and colony-forming efficiency in three cell lines. Our study provides substantial new information to advance our understanding of prostate cancer genetics and biology. SIGNIFICANCE: This study identifies novel prostate cancer genetic loci and possible causal genes, advancing our understanding of the molecular mechanisms that drive prostate cancer

Genome-wide association study identifies susceptibility loci for B-cell childhood acute lymphoblastic leukemia.

Genome-wide association studies (GWAS) have advanced our understanding of susceptibility to B-cell precursor acute lymphoblastic leukemia (BCP-ALL); however, much of the heritable risk remains unidentified. Here, we perform a GWAS and conduct a meta-analysis with two existing GWAS, totaling 2442 cases and 14,609 controls. We identify risk loci for BCP-ALL at 8q24.21 (rs28665337, P = 3.86 × 10-9, odds ratio (OR) = 1.34) and for ETV6-RUNX1 fusion-positive BCP-ALL at 2q22.3 (rs17481869, P = 3.20 × 10-8, OR = 2.14). Our findings provide further insights into genetic susceptibility to ALL and its biology

Does true Gleason pattern 3 merit its cancer descriptor?

Nearly five decades following its conception, the Gleason grading system remains a cornerstone in the prognostication and management of patients with prostate cancer. In the past few years, a debate has been growing whether Gleason score 3 + 3 = 6 prostate cancer is a clinically significant disease. Clinical, molecular and genetic research is addressing the question whether well characterized Gleason score 3 + 3 = 6 disease has the ability to affect the morbidity and quality of life of an individual in whom it is diagnosed. The consequences of treatment of Gleason score 3 + 3 = 6 disease are considerable; few men get through their treatments without sustaining some harm. Further modification of the classification of prostate cancer and dropping the label cancer for Gleason score 3 + 3 = 6 disease might be warranted

Germline variation at 8q24 and prostate cancer risk in men of European ancestry

An Author Correction to this article was published on 17 January 2019.Chromosome 8q24 is a susceptibility locus for multiple cancers, including prostate cancer. Here we combine genetic data across the 8q24 susceptibility region from 71,535 prostate cancer cases and 52,935 controls of European ancestry to define the overall contribution of germline variation at 8q24 to prostate cancer risk. We identify 12 independent risk signals for prostate cancer (p < 4.28 × 10 −15 ), including three risk variants that have yet to be reported. From a polygenic risk score (PRS) model, derived to assess the cumulative effect of risk variants at 8q24, men in the top 1% of the PRS have a 4-fold (95%CI = 3.62–4.40) greater risk compared to the population average. These 12 variants account for ~25% of what can be currently explained of the familial risk of prostate cancer by known genetic risk factors. These findings highlight the overwhelming contribution of germline variation at 8q24 on prostate cancer risk which has implications for population risk stratification. © 2018, The Author(s).Chromosome 8q24 is a susceptibility locus for multiple cancers, including prostate cancer. Here we combine genetic data across the 8q24 susceptibility region from 71,535 prostate cancer cases and 52,935 controls of European ancestry to define the overall contribution of germline variation at 8q24 to prostate cancer risk. We identify 12 independent risk signals for prostate cancer (p < 4.28 × 10 −15 ), including three risk variants that have yet to be reported. From a polygenic risk score (PRS) model, derived to assess the cumulative effect of risk variants at 8q24, men in the top 1% of the PRS have a 4-fold (95%CI = 3.62–4.40) greater risk compared to the population average. These 12 variants account for ~25% of what can be currently explained of the familial risk of prostate cancer by known genetic risk factors. These findings highlight the overwhelming contribution of germline variation at 8q24 on prostate cancer risk which has implications for population risk stratification. © 2018, The Author(s).Peer reviewe

Runs of homozygosity and testicular cancer risk

Background: Testicular germ cell tumour (TGCT) is highly heritable but > 50% of the genetic risk remains unexplained. Epidemiological observation of greater relative risk to brothers of men with TGCT compared to sons has long alluded to recessively acting TGCT genetic susceptibility factors, but to date none have been reported. Runs of homozygosity (RoH) are a signature indicating underlying recessively acting alleles and have been associated with increased risk of other cancer types. / Objective: To examine whether RoH are associated with TGCT risk. / Methods: We performed a genome‐wide RoH analysis using GWAS data from 3206 TGCT cases and 7422 controls uniformly genotyped using the OncoArray platform. / Results: Global measures of homozygosity were not significantly different between cases and controls, and the frequency of individual consensus RoH was not significantly different between cases and controls, after correction for multiple testing. RoH at three regions, 11p13‐11p14.3, 5q14.1‐5q22.3 and 13q14.11‐13q.14.13, were, however, nominally statistically significant at p < 0.01. Intriguingly, RoH200 at 11p13‐11p14.3 encompasses Wilms tumour 1 (WT1), a recognized cancer susceptibility gene with roles in sex determination and developmental transcriptional regulation, processes repeatedly implicated in TGCT aetiology. / Discussion and conclusion: Overall, our data do not support a major role in the risk of TGCT for recessively acting alleles acting through homozygosity, as measured by RoH in outbred populations of cases and controls

The endothelial glycocalyx: composition, functions, and visualization

This review aims at presenting state-of-the-art knowledge on the composition and functions of the endothelial glycocalyx. The endothelial glycocalyx is a network of membrane-bound proteoglycans and glycoproteins, covering the endothelium luminally. Both endothelium- and plasma-derived soluble molecules integrate into this mesh. Over the past decade, insight has been gained into the role of the glycocalyx in vascular physiology and pathology, including mechanotransduction, hemostasis, signaling, and blood cell–vessel wall interactions. The contribution of the glycocalyx to diabetes, ischemia/reperfusion, and atherosclerosis is also reviewed. Experimental data from the micro- and macrocirculation alludes at a vasculoprotective role for the glycocalyx. Assessing this possible role of the endothelial glycocalyx requires reliable visualization of this delicate layer, which is a great challenge. An overview is given of the various ways in which the endothelial glycocalyx has been visualized up to now, including first data from two-photon microscopic imaging