Hypoxia-induced transcriptional stress is mediated by ROS-induced R-loops

Hypoxia is a common feature of solid tumors and is associated with poor patient prognosis, therapy resistance and metastasis. Radiobiological hypoxia (<0.1% O2) is one of the few physiologically relevant stresses that activates both the replication stress/DNA damage response and the unfolded protein response. Recently, we found that hypoxia also leads to the robust accumulation of R-loops, which led us to question here both the mechanism and consequence of hypoxia-induced R-loops. Interestingly, we found that the mechanism of R-loop accumulation in hypoxia is dependent on non-DNA damaging levels of reactive oxygen species. We show that hypoxia-induced R-loops play a critical role in the transcriptional stress response, evidenced by the repression of ribosomal RNA synthesis and the translocation of nucleolin from the nucleolus into the nucleoplasm. Upon depletion of R-loops, we observed a rescue of both rRNA transcription and nucleolin translocation in hypoxia. Mechanistically, R-loops accumulate on the rDNA in hypoxia and promote the deposition of heterochromatic H3K9me2 which leads to the inhibition of Pol I-mediated transcription of rRNA. These data highlight a novel mechanistic insight into the hypoxia-induced transcriptional stress response through the ROS–R-loop–H3K9me2 axis. Overall, this study highlights the contribution of transcriptional stress to hypoxia-mediated tumorigenesis

Antibody profiling of patients with prostate cancer reveals differences in antibody signatures among disease stages

BACKGROUND: Previous studies of prostate cancer autoantibodies have largely focused on diagnostic applications. So far, there have been no reports attempting to more comprehensively profile the landscape of prostate cancer-associated antibodies. Specifically, it is unknown whether the quantity of antibodies or the types of proteins recognized change with disease progression. METHODS: A peptide microarray spanning the amino acid sequences of the gene products of 1611 prostate cancer-associated genes was synthesized. Serum samples from healthy male volunteers (n=15) and patients with prostate cancer (n=85) were used to probe the array. These samples included patients with various clinical stages of disease: newly diagnosed localized prostate cancer (n=15), castration-sensitive non-metastatic prostate cancer (nmCSPC, n=40), castration-resistant non-metastatic prostate cancer (n=15) and castration-resistant metastatic disease (n=15). The patients with nmCSPC received treatment with either standard androgen deprivation therapy (ADT) or an antitumor DNA vaccine encoding prostatic acid phosphatase. Serial sera samples from these individuals were also used to probe the array, to secondarily determine whether this approach could be used to detect treatment-related changes. RESULTS: We demonstrated that this peptide array yielded highly reproducible measurements of serum IgG levels. We found that the overall number of antibody responses did not increase with disease burden. However, the composition of recognized proteins shifted with clinical stage of disease. Our analysis revealed that the largest difference was between patients with castration-sensitive and castration-resistant disease. Patients with castration-resistant disease recognized more proteins associated with nucleic acid binding and gene regulation compared with men in other groups. Our longitudinal data showed that treatments can elicit antibodies detectable by this array, and notably vaccine-treated patients developed increased responses to more proteins over the course of treatment than did ADT-treated patients. CONCLUSIONS: This study represents the largest survey of prostate cancer-associated antibodies to date. We have been able to characterize the classes of proteins recognized by patients and determine how they change with disease burden. Our findings further demonstrate the potential of this platform for measuring antigen spread and studying responses to immunomodulatory therapies

Genetics of neurodegenerative diseases: insights from high-throughput resequencing

During the past three decades, we have witnessed remarkable advances in our understanding of the molecular etiologies of hereditary neurodegenerative diseases, which have been accomplished by ‘positional cloning’ strategies. The discoveries of the causative genes for hereditary neurodegenerative diseases accelerated not only the studies on the pathophysiologic mechanisms of diseases, but also the studies for the development of disease-modifying therapies. Genome-wide association studies (GWAS) based on the ‘common disease–common variants hypothesis’ are currently undertaken to elucidate disease-relevant alleles. Although GWAS have successfully revealed numerous susceptibility genes for neurodegenerative diseases, odds ratios associated with risk alleles are generally low and account for only a small proportion of estimated heritability. Recent studies have revealed that the effect sizes of the disease-relevant alleles that are identified based on comprehensive resequencing of large data sets of Parkinson disease are substantially larger than those identified by GWAS. These findings strongly argue for the role of the ‘common disease–multiple rare variants hypothesis’ in sporadic neurodegenerative diseases. Given the rapidly improving technologies of next-generation sequencing next-generation sequencing (NGS), we expect that NGS will eventually enable us to identify all the variants in an individual's personal genome, in particular, clinically relevant alleles. Beyond this, whole genome resequencing is expected to bring a paradigm shift in clinical practice, where clinical practice including diagnosis and decision-making for appropriate therapeutic procedures is based on the ‘personal genome’. The personal genome era is expected to be realized in the near future, and society needs to prepare for this new era

The Utility of 64 Channel Multidetector CT Angiography for Evaluating the Renal Vascular Anatomy and Possible Variations: a Pictorial Essay

The increased use of laparoscopic nephrectomy and nephron-sparing surgery has prompted the need for a more detailed radiological evaluation of the renal vascular anatomy. Multidetector CT angiography is a fast and accurate modality for assessing the precise anatomy of the renal vessels. In this pictorial review, we present the multidetector CT angiography appearances of the normal renal vascular anatomy and a spectrum of various anomalies that require accurate vascular depiction before undergoing surgical treatment

Assessing connectivity between an overlying aquifer and a coal seam gas resource using methane isotopes, dissolved organic carbon and tritium

Coal seam gas (CSG) production can have an impact on groundwater quality and quantity in adjacent or overlying aquifers. To assess this impact we need to determine the background groundwater chemistry and to map geological pathways of hydraulic connectivity between aquifers. In south-east Queensland (Qld), Australia, a globally important CSG exploration and production province, we mapped hydraulic connectivity between the Walloon Coal Measures (WCM, the target formation for gas production) and the overlying Condamine River Alluvial Aquifer (CRAA), using groundwater methane (CH4) concentration and isotopic composition (δ13C-CH4), groundwater tritium (3H) and dissolved organic carbon (DOC) concentration. A continuous mobile CH4 survey adjacent to CSG developments was used to determine the source signature of CH4 derived from the WCM. Trends in groundwater δ13C-CH4 versus CH4 concentration, in association with DOC concentration and 3H analysis, identify locations where CH4 in the groundwater of the CRAA most likely originates from the WCM. The methodology is widely applicable in unconventional gas development regions worldwide for providing an early indicator of geological pathways of hydraulic connectivity

Identity-by-descent filtering as a tool for the identification of disease alleles in exome sequence data from distant relatives

Large-scale, deep resequencing may be the next logical step in the genetic investigation of common complex diseases. Because each individual is likely to carry many thousands of variants, the identification of causal alleles requires an efficient strategy to reduce the number of candidate variants. Under many genetic models, causal alleles can be expected to reside within identity-by-descent (IBD) regions shared by affected relatives. In distant relatives, IBD regions constitute a small portion of the genome and can thus greatly reduce the search space for causal alleles. However, the effectiveness of this strategy is unknown. We test the simulated mini-exome data set in extended pedigrees provided by Genetic Analysis Workshop 17. At the fourth- and fifth-degree level of relatedness, case-case pairs shared between 1% and 9% of the genome identical by descent. As expected, no genes were shared identical by descent by all case subjects, but 43 genes were shared by many case subjects across at least 50 replicates. We filtered variants in these genes based on population frequency, function, informativeness, and evidence of association using the family-based association test. This analysis highlighted five genes previously implicated in triglyceride, lipid, and cholesterol metabolism. Comparison with the list of true risk alleles revealed that strict IBD filtering followed by association testing of the rarest alleles was the most sensitive strategy. IBD filtering may be a useful strategy for narrowing down the list of candidate variants in exome data, but the optimal degree of relatedness of affected pairs will depend on the genetic architecture of the disease under study

Cold Atmospheric Plasma Stimulates Clathrin-Dependent Endocytosis to Repair Oxidised Membrane and Enhance Uptake of Nanomaterial in Glioblastoma Multiforme Cells

peer-reviewedCold atmospheric plasma (CAP) enhances uptake and accumulation of nanoparticles and promotes synergistic cytotoxicity against cancer cells. However, the mechanisms are not well understood. In this study, we investigate the enhanced uptake of theranostic nanomaterials by CAP. Numerical modelling of the uptake of gold nanoparticle into U373MG Glioblastoma multiforme (GBM) cells predicts that CAP may introduce a new uptake route. We demonstrate that cell membrane repair pathways play the main role in this stimulated new uptake route, following non-toxic doses of dielectric barrier discharge CAP. CAP treatment induces cellular membrane damage, mainly via lipid peroxidation as a result of reactive oxygen species (ROS) generation. Membranes rich in peroxidised lipids are then trafficked into cells via membrane repairing endocytosis. We confirm that the enhanced uptake of nanomaterials is clathrin-dependent using chemical inhibitors and silencing of gene expression. Therefore, CAP-stimulated membrane repair increases endocytosis and accelerates the uptake of gold nanoparticles into U373MG cells after CAP treatment. We demonstrate the utility of CAP to model membrane oxidative damage in cells and characterise a previously unreported mechanism of membrane repair to trigger nanomaterial uptake. This knowledge will underpin the development of new delivery strategies for theranostic nanoparticles into cancer cells

(En)countering counterfeits in Bangkok: the urban spatial interlegalities of intellectual property law, enforcement and tolerance

In a Bangkok mall a fibreglass policeman warning against intellectual property (IP) piracy stands just metres away from vendors selling fake DVDs; a scene indicative of incomplete and unsuccessful attempts by foreign governments (the US and EU in particular) and corporate actors at enrolment towards ever-higher IP standards – the ‘IP ratchet’ that Drahos (2004 Intellectual property and pharmaceutical markets: a nodal governance approach Temple Law Review 77 401–24) describes. But the scene also reflects cultural resistance at the local level. Both readings exemplify the range of historical, cultural, and politico-legal factors at play that can only be understood through engagement with vendors and consumers in the markets and malls of Bangkok. IP laws may achieve partial ‘closure’ but are regularly changing, contested, variably enforced, and subject to existing social norms such as the ‘cult of imitation’, cultures of legal informality, and a lack of social contract. We found that this lack of legal closure was most pronounced in the day-to-day operation of the Pratunam Market. Whilst other sites host regular crack-downs by police, the IP-specific DSI force, and the Thai courts, markets like Pratunam are mostly immune despite being a transnational trade node for the production and export of counterfeit garments with other developing countries, and a non-conforming node in the IP enforcement context. In the face of persistent efforts to transpose Euro-American IP laws in countries like Thailand, alternative and resistant nodes representing ‘spaces of interlegalities’ are likely to persevere because of the historical context, and the socio-cultural norms of these places