Genetics
Abstract
Understanding the genetic causes of diseases affecting pancreatic β cells and neurons can give insights into pathways essential for both cell types. Microcephaly, epilepsy and diabetes syndrome (MEDS) is a congenital disorder with two known aetiological genes, IER3IP1 and YIPF5. Both genes encode proteins involved in endoplasmic reticulum (ER) to Golgi trafficking. We used genome sequencing to identify 6 individuals with MEDS caused by biallelic variants in the novel disease gene, TMEM167A. All had neonatal diabetes (diagnosed <6 months) and severe microcephaly, five also had epilepsy. TMEM167A is highly expressed in developing and adult human pancreas and brain. To gain insights into the mechanisms leading to diabetes, we silenced TMEM167A in EndoC-βH1 cells and knocked-in one patient’s variant, p.Val59Glu, in induced pluripotent stem cells (iPSCs). Both TMEM167A depletion in EndoC-βH1 cells and the p.Val59Glu variant in iPSC-derived β cells sensitized β cells to ER stress. The p.Val59Glu variant impaired proinsulin trafficking to the Golgi and induced iPSC-β cell dysfunction. The discovery of TMEM167A variants as a new genetic cause of MEDS highlights a critical role of TMEM167A in the ER to Golgi pathway in β cells and neurons.
Authors
Enrico Virgilio, Sylvia Tielens, Georgia Bonfield, Fang-Shin Nian, Toshiaki Sawatani, Chiara Vinci, Molly Govier, Hossam Montaser, Romane Lartigue, Anoop Arunagiri, Alexandrine Liboz, Flavia Natividade da Silva, Maria Lytrivi, Theodora Papadopoulou, Matthew N. Wakeling, James Russ-Silsby, Pamela Bowman, Matthew B. Johnson, Thomas W. Laver, Anthony Piron, Xiaoyan Yi, Federica Fantuzzi, Sirine Hendrickx, Mariana Igoillo-Esteve, Bruno J. Santacreu, Jananie Suntharesan, Radha Ghildiyal, Darshan G. Hegde, Nikhil Avnish Shah, Sezer Acar, Beyhan Özkaya Dönmez, Behzat Özkan, Fauzia Mohsin, Iman M. Talaat, Mohamed Tarek Abbas, Omar Saied Abbas, Hamed Ali Alghamdi, Nurgun Kandemir, Sarah E. Flanagan, Raphael Scharfmann, Peter Arvan, Matthieu Raoux, Laurent Nguyen, Andrew T. Hattersley, Miriam Cnop, Elisa De Franco
Abstract
BACKGROUND. Localized high-risk prostate cancer (PCa) often recurs despite neoadjuvant androgen deprivation therapy (ADT). We sought to identify baseline molecular programs that predict pathologic response and reveal targetable vulnerabilities. METHODS. We profiled 147 biopsy foci from 48 MRI-visible lesions in 37 patients before 6 months of ADT plus enzalutamide and radical prostatectomy. Residual cancer burden (RCB) at prostatectomy was the primary outcome. Analyses incorporated PTEN loss, TMPRSS2:ERG status, and HER2/androgen receptor (AR) immunohistochemistry on baseline and posttreatment tissues. Findings were evaluated in an external transcriptional cohort (n = 121) and by multiplex immunostaining in an independent cohort (n = 61). Functional assays tested enzalutamide-responsive enhancers near ERBB2 and sensitivity to HER2 inhibition. RESULTS. A baseline HER2-associated transcriptional program correlated with higher RCB and inversely with AR activity, independent of PTEN and ERG. Exceptional responders had lower HER2 protein in pretreatment biopsies. The inverse AR-HER2 relationship recurred across datasets and multiplex immunostaining, which revealed coexisting AR-high/HER2-low and HER2-high/AR-low subpopulations. Enzalutamide inhibited AR-mediated repression of ERBB2. HER2-high, AR-low cells present before therapy resisted ADT yet were sensitive to HER2 inhibitors; combining HER2 inhibitors with enzalutamide increased tumor cell killing. These findings were reproduced in the external cohort and orthogonal assays. CONCLUSION. Baseline HER2 activity marks intrinsic resistance to neoadjuvant ADT in localized high-risk PCa and identifies a preexisting, targetable AR-low subpopulation. HER2-directed therapy, alone or with AR blockade, warrants clinical evaluation. TRIAL REGISTRATION. ClinicalTrials.gov registration: NCT02430480. FUNDING. Prostate Cancer Foundation; Department of Defense Prostate Cancer Research Program; National Institutes of Health.
Authors
Scott Wilkinson, Anson T. Ku, Rosina T. Lis, Isaiah M. King, Daniel Low, Shana Y. Trostel, John R. Bright, Nicholas T. Terrigino, Anna Baj, Emily R. Summerbell, Kayla E. Heyward, Sumeyra Kartal, John M. Fenimore, Chennan Li, Cassandra Singler, BaoHan Vo, Caroline S. Jansen, Huihui Ye, Nichelle C. Whitlock, Stephanie A. Harmon, Nicole V. Carrabba, Rayann Atway, Ross Lake, David Y. Takeda, Haydn T. Kissick, Peter A. Pinto, Peter L. Choyke, Baris Turkbey, William L. Dahut, Fatima Karzai, Adam G. Sowalsky
Abstract
Congenital hydrocephalus is a life-threatening condition that might affect brain development by increasing the pressure on the brain parenchyma. Here, we describe 6 male patients from 1 family, all presenting with an isolated X-linked congenital hydrocephalus. Exome sequencing identified a likely pathogenic variant of angiomotin (AMOT) that segregated with the phenotype in the extended family. We show that the variant, affecting the first methionine, translated into a shorter AMOT protein lacking 91 amino acids from the N-terminus. Mechanistically, we unraveled that the absence of the N-terminus leads to abnormally increased AMOT protein levels due to the loss of both the N-degron degradation signal and the tankyrase-binding domain. Altered degradation of AMOT disrupted the barrier integrity of the cells. Thus, the identified AMOT variant likely underlies the clinical presentation of isolated X-linked hydrocephalus in this family, and our data underscore the importance of tight regulation of AMOT protein level in the brain. AMOT now joins the list of genes involved in congenital hydrocephalus in humans. These findings are instrumental for the genetic counseling of affected families.
Authors
Nurcan Hastar, Hagit Daum, Nikoletta Kardos-Török, Gael Ganz, Leon Obendorf, Peter Vajkoczy, Orly Elpeleg, Petra Knaus
Abstract
Authors
Steven Q. Le, Alexander Sorensen, Soila Sukupolvi, Gianna Jewhurst, Grant L. Austin, Balraj Doray, Jonathan D. Cooper, Patricia I. Dickson
Abstract
Tumor gene alterations can serve as predictive biomarkers for therapy response. The nucleotide excision repair (NER) helicase ERCC2 carries heterozygous missense mutations in approximately 10% of bladder tumors, and these may predict sensitivity to cisplatin treatment. To explore the clinical actionability of ERCC2 mutations, we assembled a multinational cohort of 2,012 individuals with bladder cancer and applied the highly quantitative CRISPR-Select assay to functionally profile recurrent ERCC2 mutations. We also developed a single-allele editing version of CRISPR-Select to assess heterozygous missense variants in their native context. From the cohort, 506 ERCC2 mutations were identified, with 93% being heterozygous missense variants. CRISPR-Select pinpointed deleterious, cisplatin-sensitizing mutations, particularly within the conserved helicase domains. Importantly, single-allele editing revealed that heterozygous helicase-domain mutations markedly increased cisplatin sensitivity. Integration with clinical data confirmed that these mutations were associated with improved response to platinum-based neoadjuvant chemotherapy. Comparison with computational algorithms showed substantial discrepancies, highlighting the importance of precision functional assays for interpreting mutation effects in clinically relevant contexts. Our results demonstrate that CRISPR-Select provides a robust platform to advance biomarker-driven therapy in bladder cancer and supports its potential integration into precision oncology workflows.
Authors
Judit Börcsök, Diyavarshini Gopaul, Daphne Devesa-Serrano, Clémence Mooser, Nicolas Jonsson, Matteo Cagiada, Dag R. Stormoen, Maya N. Ataya, Brendan J. Guercio, Hristos Z. Kaimakliotis, Gopa Iyer, Kresten Lindorff-Larsen, Lars Dyrskjøt, Kent W. Mouw, Zoltan Szallasi, Claus S. Sørensen
Abstract
SLFN14-related thrombocytopenia is a rare bleeding disorder caused by SLFN14 mutations altering hemostasis in patients with platelet dysfunction. Schlafen (SLFN) proteins are highly conserved in mammals where SLFN14 is specifically expressed in megakaryocyte (MK) and erythroblast lineages. The role of SLFN14 in megakaryopoiesis and platelet function has not been elucidated. We generated a new murine model with a platelet- and MK-specific SLFN14 deletion using platelet factor-4 (PF4) cre-mediated deletion of exons 2 and 3 in Slfn14 (Slfn14;PF4-Cre) to decipher the molecular mechanisms driving the bleeding phenotype. SLFN14;PF4-Cre+ platelets displayed reduced platelet signaling to thrombin, reduced thrombin formation, increased bleeding tendency, and delayed thrombus formation as assessed by intravital imaging. Moreover, fewer in situ bone marrow MKs compared to controls. RNA sequencing and gene ontology analysis of MKs and platelets from Slfn14;PF4-Cre homozygous mice revealed altered pathways of ubiquitination, ATP activity, cytoskeleton and molecular function. In summary, we investigated how SLFN14 deletion in MKs and platelets leads to platelet dysfunction and alters their transcriptome, explaining the platelet dysfunction and bleeding in humans and mice with SLFN14 mutations.
Authors
Rachel J. Stapley, Xenia Sawkulycz, Gabriel H.M. Da Mota Araujo, Maximilian Englert, Lourdes Garcia-Quintanilla, Sophie R.M. Smith, Amna Ahmed, Elizabeth J. Haining, Nayandeep Kaur, Andrea Bacon, Andrey V. Pisarev, Natalie S. Poulter, Dean P.J. Kavanagh, Steven G. Thomas, Samantha J. Montague, Julie Rayes, Zoltan Nagy, Neil V. Morgan
Abstract
Mutations that initiate AML can cause clonal expansion without transformation (“clonal hematopoiesis”). Cooperating mutations, usually in signaling genes, are needed to cause overt disease, but these may require a specific “fitness state” to be tolerated. Here, we show that nearly all AMLs arising in a mouse model expressing two common AML initiating mutations (Dnmt3aR878H and Npm1cA) acquire a single copy amplification of chromosome 7, followed by activating mutations in signaling genes. We show that overexpression of a single gene on chromosome 7 (Gab2, which coordinates signaling pathways) is tolerated in the presence of the Npm1cA mutation, can accelerate the development of AML, and is important for survival of fully transformed AML cells. GAB2 is likewise overexpressed in many human AMLs with mutations in NPM1 and/or signaling genes, and also in Acute Promyelocytic Leukemia initiated by PML::RARA; the PML::RARA fusion protein may activate GAB2 by directly binding to its 5′ flanking region. A similar pattern of GAB2 overexpression preceding mutations in signaling genes has been described in other human malignancies. GAB2 overexpression may represent an oncogene-driven adaptation that facilitates the action of signaling mutations, suggesting an important (and potentially targetable) “missing link” between the initiating and progression mutations associated with AML.
Authors
Michael H. Kramer, Stephanie N. Richardson, Yang Li, Tiankai Yin, Nichole M. Helton, Daniel R. George, Michelle Cai, Sai Mukund Ramakrishnan, Casey D.S. Katerndahl, Christopher A. Miller, Timothy J. Ley
Abstract
Authors
Nathalie Baumlin, Sumedha Gunewardena, Scott H. Randell, Frank Horrigan, Matthias Salathe
Abstract
The leukemia fusion gene CBFB-MYH11 requires RUNX1 for leukemogenesis, but the underlying mechanism is unclear. By in vitro studies, we found that CBFβ-SMMHC, the chimeric protein encoded by CBFB-MYH11, could enhance the binding affinity between RUNX1 and its target DNA. Increased RUNX1-DNA binding was also observed in myeloid progenitor cells from mice expressing CBFβ-SMMHC. Moreover, only CBFβ-SMMHC variants able to enhance the DNA binding affinity by RUNX1 could induce leukemia in mouse models. Marked transcriptomic changes, affecting genes associated with inflammatory response and target genes of CBFA2T3, were observed in mice expressing leukemogenic CBFβ-SMMHC variants. Finally, we show that CBFβ-SMMHC could not induce leukemia in mice with a Runx1-R188Q mutation, which reduces RUNX1 DNA binding but not affecting its interaction with CBFβ-SMMHC or its sequestration to cytoplasm by CBFβ-SMMHC. Our data suggest that, in addition to binding RUNX1 to regulate gene expression, enhancing RUNX1 binding affinity to its target DNA is an important mechanism by which CBFβ-SMMHC contributes to leukemogenesis, highlighting RUNX1–DNA interaction as a potential therapeutic target in inv(16) AML.
Authors
Tao Zhen, Yaqiang Cao, Tongyi Dou, Yun Chen, Guadalupe Lopez, Ana Catarina Menezes, Xufeng Wu, John Hammer, Jun Cheng, Lisa Garrett, Stacie Anderson, Martha Kirby, Stephen Wincovitch, Bayu Sisay, Abdel G. Elkahloun, Di Wu, Lucio H. Castilla, Wei Yang, Jiansen Jiang, Keji Zhao, Paul P. Liu
Abstract
Authors
Elena Godoy-Molina, Natalia L. Serrano, Aquilina Jiménez-González, Miquel Villaronga, Rosa M. Marqués Pérez-Bryan, Rubén Varela-Fernández, Stephanie Lotz-Esquivel, Alba Hevia Tuñón, Prachi P. Trivedi, Nina Horn, Joseph F. Standing, Víctor Mangas-Sanjuan, Mercè Capdevila, Aurora Mateos, Denis Broun, Svetlana Lutsenko, Ines Medina-Rivera, Rafael Artuch, Cristina Jou, Mònica Roldán, Pedro Arango-Sancho, Mónica Saez-Villafañe, Juan J. Ortiz-de-Urbina, Angela Pieras-López, Marta Duero, Rosa Farré, Jordi Pijuan, Janet Hoenicka, James C. Sacchettini, Michael J. Petris, Vishal M. Gohil, Francesc Palau
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)