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Biology subjects

McFarlane, M.

Publications and source records attributed to McFarlane, M..

6 recordsLinked to original sources

Genomic Determinants of Lethality and Therapeutic Vulnerability in Castration-Resistant Prostate Cancer

Despite extensive characterization, the molecular determinants that shape disease progression and therapeutic outcomes in metastatic castration-resistant prostate cancer (mCRPC) remain incompletely defined. This large, multi-institutional analysis reveals that the genomic determinants of outcomes in primary prostate cancer are distinct from those in castration-resistant disease. We identify androgen-regulated MYC fusions as potent primary genetic drivers catalyzing early progression. Additionally, across independent mCRPC cohorts, we validate TP53, RB1, and CDKN1B alterations as the strongest genetic drivers of poor survival. Mechanistically, CDKN1B loss induces an AR-positive epithelial-mesenchymal transition rather than neuroendocrine differentiation, while TP53 loss triggers whole-genome duplication and subsequent adaptive copy-number gains. Within TP53-altered tumors, AR amplifications confer improved survival while AR mutations are protective regardless of TP53 status. Integrating these genomic events with transcriptomic phenotypes, we derive CAPrisk, a multi-omic prognostic classifier. CAPrisk stratifies patients with mCRPC into three risk groups with >33-month survival differences and predicts outcomes across androgen receptor pathway inhibitors, taxanes, PARP-inhibitors, and radium-223. Together, these findings expand the clinical utility of genomic profiling in advanced prostate cancer and establish a framework for risk stratification in lethal disease. IN BRIEF (eTOC BLURB)Rebernick et al. analyze a multi-institutional cohort of 1,331 prostate cancer samples and identify the genomic determinants of progression to lethal, castration-resistant disease. They define rare AR-regulated MYC fusions and haploinsufficient CDKN1B loss as drivers of poor outcome while highlighting AR alterations as predictors of improved prognosis. They develop CAPrisk, a multi-omic classifier that stratifies patient outcomes across androgen receptor pathway inhibitors, taxanes, PARP-inhibitors, and radium-223. HIGHLIGHTS- AR-regulated MYC fusions are rare ([~]2%) truncal events driving aggressive disease. - Distinct AR alterations drive favorable outcomes in TP53-altered and non-altered contexts. - Haploinsufficient CDKN1B loss predicts poor survival in AR-positive tumors. - A multi-omic model predicts outcomes across four standard-of-care therapies. MI-OncoSeq TeamChandan Kumar, Erica Rabban, Kayla Muschong, Lakshmi P. Kunju, Javed Siddiqui, Yu Ning, Rui Wang, Fengyun Su, Yelena Kleyman-Smith, Josh N. Vo, Jin Chen, Rahul Mannan Stand Up To Cancer TeamWassim Abida, Joanna Cyrta, Glenn Heller, Davide Prandi, Joshua Armenia, Ilsa Coleman, Matteo Benelli, Eliezer M. Van Allen, Andrea Sboner, Tarcisio Fedrizzi, Juan Miguel Mosquera, Brian D. Robinson, Navonil De Sarkar, Lakshmi P. Kunju, Scott Tomlins, Daniel Nava Rodrigues, Massimo Loda, Anuradha Gopalan, Victor E. Reuter, Colin C. Pritchard, Joaquin Mateo, Diletta Bianchini, Susana Miranda, Suzanne Carreira, Pasquale Rescigno, Julie Filipenko, Jacob Vinson, Robert B. Montgomery, Himisha Beltran, Elisabeth I. Heath, Howard I. Scher, Philip W. Kantoff, Mary-Ellen Taplin, Nikolaus Schultz, Johann S. deBono, Francesca Demichelis, Peter S. Nelson, Mark A. Rubin, Charles Sawyers

Cancer Biology↗

SFTSV NSs protein is a novel tick antiviral RNAi response suppressor

Severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging tick-borne phenuivirus causing high mortality in humans. While the non-structural protein NSs is dispensable for replication in interferon-deficient mammalian cells, we demonstrate for the first time that NSs is essential for viral replication in tick cells. SFTSV infection triggers canonical Dicer-2-mediated antiviral RNA interference (RNAi) in tick cells, producing virus-derived small interfering RNAs (siRNAs) that target viral transcripts for degradation. We show that NSs functions as a viral suppressor of RNAi by selectively engaging and depleting single-stranded RNAs derived from 22-nucleotide siRNAs, likely limiting their incorporation into RNA-induced silencing complexes (RISC). Complementation with a heterologous RNAi suppressor (p19 protein) partially rescues replication of NSs-deficient virus, validating the RNAi suppressive function of NSs. These findings reveal that successful tick-borne viral replication requires host-specific immune evasion strategies and establish NSs-mediated RNAi suppression as essential for SFTSV persistence in arthropod vectors. Significance StatementThis study reveals a critical requirement for SFTSV infection that differs between hosts. While the viral NSs protein is dispensable in interferon deficient mammalian cells, it is essential for replication in tick cells, the natural vectors of the virus. We show that NSs functions as a viral RNA silencing suppressor by associating with virus derived small RNAs and limiting their availability to the tick antiviral RNA interference machinery. This provides mechanistic insight into how tick-borne viruses evade arthropod immune defences through engagement of functional siRNAs rather than broad inhibition of RNA interference pathways. Together, these findings demonstrate that SFTSV employs distinct immune evasion strategies in different hosts and identify NSs as a key determinant of vector cell infection.

microbiology↗

From prototype to outbreak: conserved pathogenesis of Oropouche virus in a novel murine pregnancy model highlights its public health implications

Oropouche virus (OROV) is an emerging orthobunyavirus responsible for widespread outbreaks across South and Central America. The recent surge in congenital infections has raised urgent concerns about OROVs threat to maternal and fetal health. Here, we establish an in vivo model of OROV vertical transmission using the ancestral (prototype) strain BeAn19991 in immunocompetent C57BL/6J mice. We demonstrate that OROV efficiently replicates in maternal tissues, crosses the maternal-fetal interface, and infects both placental and fetal tissues. Parallel infections in human trophoblast-derived cell lines confirm conserved placental tropism across the ancestral strain and a contemporary (outbreak) isolate from the current outbreak. Importantly, we show that vertical transmission is not a recently acquired trait but a long-standing feature of OROV biology. Offspring born to infected dams mount neutralizing antibody responses and exhibit partial protection upon challenge. These findings conclusively confirm OROV as a vertically transmissible arbovirus, highlighting the urgent need to integrate OROV into surveillance, diagnostic, and vaccine preparedness efforts.

microbiology↗

Enhanced fluorescence from semiconductor quantum dot-labelled cells excited at 280 nm

Semiconductor quantum dots (QDs) have significant advantages over more traditional fluorophores used in fluorescence microscopy including reduced photobleaching, long-term photostability and high quantum yields, but due to limitations in light sources and optics, are often excited far from their optimum excitation wavelengths in the deep-UV. Here, we present a quantitative comparison of the excitation of semiconductor QDs at a wavelength of 280 nm, compared to the longer wavelength of 365 nm, within a cellular environment. We report increased fluorescence intensity and enhanced image quality when using 280 nm excitation compared to 365 nm excitation for cell imaging across multiple datasets, with a highest average fluorescence intensity increase of 3.59-fold. We also find no significant increase in photobleaching of QDs associated with 280 nm excitation.

biophysics↗

COVID-19: A need for new rather than repurposed antiviral drugs.

BackgroundSARS-CoV-2 infection, the causative agent of COVID-19, has resulted in over 2,500,000 deaths to date1. Although vaccines are becoming available, treatment options remain limited. Repurposing of compounds could reduce the time, cost, and risks associated with the development of new drugs and has been the focus of many clinical studies. Here, we summarise available evidence on 29 FDA-approved compounds, from in vitro results to clinical trials, focussing on remdesivir, galidesivir and favipiravir, and test 29 antiviral compounds activity in vitro. MethodsA comprehensive search strategy was used to retrieve trials and publications related to antiviral compounds with potential efficacy to treat coronaviruses. These data were used to prioritise testing of a panel of antiviral drugs in vitro against patient isolates of SARS-CoV-2. An in vitro screen was carried out to determine the activity of 29 FDA-approved compounds. Results625 clinical trials investigated 16 repurposed antiviral candidate compounds for the treatment of COVID-19. In vitro studies identified ten drug candidates with demonstrable anti-SARS-CoV-2 activity, including favipiravir, remdesivir, and galidesivir. To validate these findings, a drug screen was conducted using two cell lines and wildtype isolates of SARS-CoV-2 isolated from patients in the UK. While eight drugs with anti-SARS-CoV-2 activity were identified in vitro, activity in clinical trials has, as yet failed to demonstrate a strong effect on mortality. ConclusionsSo far, no repurposed antiviral has shown a strong effect on mortality in clinical studies. The urgent need for novel antivirals in this pandemic is clear, despite the costs and time associated with their development. Research in ContextO_ST_ABSEvidence before this studyC_ST_ABSRepurposing of existing compounds for the treatment of COVID-19 has been the focus of many in vitro studies and clinical trials, saving time, costs and risks associated with the research and development of new compounds. Added value of this studyWe reviewed the literature for 29 FDA-approved compounds with previously reported (or suspected) anti-SARS-CoV-2 activity and found 625 clinical trials that have been undertaken on 16 different drugs. We determined if repurposed antivirals are suitable for clinical trials based on previously published data, and conducted an additional in vitro screen using locally circulating strains in the UK (PHE2 and GLA1). We report the difference in IC50 from published data using Wuhan1/Wash1 strains with PHE2 and GLA1, including IC50 values below 100M for galidesivir in wild-type virus. Given the limited success of repurposed compounds in the treatment of COVID-19, we comment on the urgent need for new antivirals specifically targeting SARS-CoV-2. Implications of all the available evidenceOur data show that most prospective compounds for repurposing show no anti-SARS-CoV-2 activity, and antiviral activity in vitro does not always translate to clinical benefit. So far, no repurposed compound has shown a strong effect on mortality in clinical studies. Drugs, including monoclonal antibody therapies, that have been developed to target SARS-CoV-2 virus itself have shown most promise.

microbiology↗

Sugar feeding enhances gut immunity and protects against arboviral infection in the mosquito vector Aedes aegypti

As mosquito females require a blood meal to reproduce, they can act as vectors of numerous pathogens, such as arboviruses (e.g. Zika, dengue and chikungunya viruses), which constitute a substantial worldwide public health burden. In addition to blood meals, mosquito females can also take sugar meals to get carbohydrates for their energy reserves. It is now recognised that diet is a key regulator of health and disease outcome through interactions with the immune system. However, it has been mostly studied in humans and model organisms. So far, the impact of sugar feeding on mosquito immunity and in turn, how this could affect vector competence for arboviruses has not been analysed. Here, we show that sugar feeding increases and maintains antiviral immunity in the digestive tract of the main arbovirus vector Aedes aegypti. Our data demonstrate that the gut microbiota does not mediate the sugar-induced immunity but partly inhibits it. Importantly, sugar intake prior to an arbovirus-infected blood meal further protects females against infection with arboviruses from different families, highlighting a broad antiviral action of sugar. Sugar feeding blocks arbovirus initial infection and dissemination from the gut, lowers infection prevalence and intensity, thereby decreasing transmission potential of female mosquitoes. Overall, our findings uncover a crucial role of sugar feeding in mosquito antiviral immunity and vector competence for arboviruses. Since Ae. aegypti almost exclusively feed on blood in some natural settings, our findings suggest that this could increase the spread of mosquito-borne arboviral diseases.

physiology↗