Pre-mRNA splicing is a highly coordinated process. While its dysregulation has been linked to neurological deficits, our understanding of the underlying molecular and cellular mechanisms remains limited. We implicated pathogenic variants in U2AF2 and PRPF19, encoding spliceosome subunits in neurodevelopmental disorders (NDDs), by identifying 46 unrelated individuals with 23 de novo U2AF2 missense variants (including seven recurrent variants in 30 individuals) and six individuals with de novo PRPF19 variants. Eight U2AF2 variants dysregulated splicing of a model substrate. Neuritogenesis was reduced in human neurons differentiated from human pluripotent stem cells carrying two U2AF2 hyper-recurrent variants. Neural loss of function of the Drosophila orthologs, U2af50 and Prp19, led to lethality, abnormal mushroom body (MB) patterning, and social deficits, differentially rescued by wild-type and mutant U2AF2 or PRPF19. Transcriptome profiling revealed splicing substrates or effectors (including Rbfox1, a third splicing factor), which rescued MB defects in U2af50 deficient flies. Upon re-analysis of negative clinical exomes followed by data sharing, we further identified six NDD patients carrying RBFOX1 missense variants which, by in vitro testing, showed loss of function. Our study implicates three splicing factors as NDD causative genes and establishes a genetic network with hierarchy underlying human brain development and function.
Dong Li, Qin Wang, Allan Bayat, Mark R. Battig, Yijing Zhou, Daniëlle G.M. Bosch, Gijs van Haaften, Leslie Granger, Andrea K. Petersen, Luis A. Pérez-Jurado, Gemma Aznar-Laín, Anushree Aneja, Miroslava Hancarova, Sarka Bendova, Martin Schwarz, Radka Kremlíková Pourová, Zdenek Sedlacek, Beth A. Keena, Michael E. March, Cuiping Hou, Nora O'Connor, Elizabeth J. Bhoj, Margaret H. Harr, Gabrielle Lemire, Kym M. Boycott, Meghan C. Towne, Megan Li, Mark Tarnopolsky, Lauren Brady, Michael J. Parker, Hanna Faghfoury, Lea Kristin Parsley, Emanuele Agolini, Maria Lisa Dentici, Antonio Novelli, Meredith S. Wright, Rachel Palmquist, Khanh Lai, Marcello Scala, Pasquale Striano, Michele Iacomino, Federico Zara, Annina Cooper, Timothy J. Maarup, Melissa Byler, Robert Roger Lebel, Tugce B. Balci, Raymond J. Louie, Michael J. Lyons, Jessica Douglas, Catherine B. Nowak, Alexandra Afenjar, Juliane Hoyer, Boris Keren, Saskia M. Maas, Mahdi M. Motazacker, Julian A. Martinez-Agosto, Ahna M. Rabani, Elizabeth M. McCormick, Marni Falk, Sarah M. Ruggiero, Ingo Helbig, Rikke S. Møller, Lino Tessarollo, Francesco Tomassoni-Ardori, Mary Ellen Palko, Tzung-Chien Hsieh, Peter M. Krawitz, Mythily Ganapathi, Bruce D. Gelb, Vaidehi Jobanputra, Ashley Wilson, John Greally, Sébastien Jacquemont, Khadijé Jizi, Bruel Ange-Line, Chloé Quelin, Vinod K. Misra, Erika Chick, Corrado Romano, Donatella Greco, Alessia Arena, Manuela Morleo, Vincenzo Nigro, Rie Seyama, Yuri Uchiyama, Naomichi Matsumoto, Ryoji Taira, Katsuya Tashiro, Yasunari Sakai, Gökhan Yigit, Bernd Wollnik, Michael Wagner, Barbara Kutsche, Anna C.E. Hurst, Michelle L. Thompson, Ryan J. Schmidt, Linda M. Randolph, Rebecca C. Spillmann, Vandana Shashi, Edward J. Higginbotham, Dawn Cordeiro, Amanda Carnevale, Gregory Costain, Tayyaba Khan, Benoît Funalot, Frederic Tran Mau-Them, Luis Fernandez Garcia Moya, Sixto García-Miñaúr, Matthew Osmond, Lauren Chad, Nada Quercia, Diana Carrasco, Chumei Li, Amarilis Sanchez-Valle, Meghan Kelley, Mathilde Nizon, Brynjar O. Jensson, Patrick Sulem, Kari Stefansson, Svetlana Gorokhova, Tiffany Busa, Marlène Rio, Hamza Hadj Abdallah, Marion Lesieur-Sebellin, Jeanne Amiel, Véronique Pingault, Sandra Mercier, Marie Vincent, Christophe Philippe, Clemence Fatus-Fauconnier, Kathryn Friend, Rebecca K. Halligan, Sunita Biswas, Jane M.R. Rosser, Cheryl Shoubridge, Mark A. Corbett, Christopher Barnett, Jozef Gecz, Kathleen A. Leppig, Anne Slavotinek, Carlo Marcelis, Rolph Pfundt, Bert B.A. de Vries, Marjon A. van Slegtenhorst, Alice S. Brooks, Benjamin Cogne, Thomas Rambaud, Zeynep Tümer, Elaine H. Zackai, Naiara Akizu, Yuanquan Song, Hakon Hakonarson
Recent studies using cell type-specific knockout mouse models have improved our understanding of the pathophysiological relevance of SEL1L-HRD1 endoplasmic reticulum (ER)-associated degradation (ERAD); however, its importance in humans remains unclear as no disease variant has been identified. Here we report the identification of three bi-allelic missense variants of SEL1L and HRD1 (or SYVN1) in six children from three independent families presenting with developmental delay, intellectual disability, microcephaly, facial dysmorphisms, hypotonia and/or ataxia. These SEL1L (p.Gly585Asp, p.Met528Arg) and HRD1 (p.Pro398Leu) variants were hypomorphic and impaired ERAD function at distinct steps of ERAD including substrate recruitment (SEL1L p.Gly585Asp), SEL1L-HRD1 complex formation (SEL1L p.Met528Arg), and HRD1 activity (HRD1 p.Pro398Leu). Our study not only provide new insights into the structure-function relationship of SEL1L-HRD1 ERAD, but also establish the importance of SEL1L-HRD1 ERAD in humans.
Huilun Helen Wang, Liangguang Leo Lin, Zexin Jason Li, Xiaoqiong Wei, Omar Askander, Gerarda Cappuccio, Mais O. Hashem, Laurence Hubert, Arnold Munnich, Mashael Alqahtani, Qi Pang, Margit Burmeister, You Lu, Karine Poirier, Claude Besmond, Shengyi Sun, Nicola Brunetti-Pierri, Fowzan S. Alkuraya, Ling Qi
SEL1L-HRD1 ERAD plays a critical role in many physiological processes in mice, including immunity, water homeostasis and energy metabolism; however, its relevance and importance in humans remain unclear as no disease variant has been identified. Here we report a bi-allelic SEL1L variant (p. Cys141Tyr) in five patients from a consanguineous Slovakian family. These patients presented with not only ERAD-associated neurodevelopmental disorders with onset infancy (ENDI) syndromes, but infantile-onset agammaglobulinemia with no mature B cells, resulting in frequent infections and early death. This variant disrupted the formation of a disulfide bond in the luminal fibronectin II domain of SEL1L, largely abolishing the function of SEL1L-HRD1 ERAD complex in part via proteasomal-mediated self-destruction by HRD1. This study reports a new disease entity termed the “ENDI-agammaglobulinemia” (ENDI-A) syndrome and establishes an inverse correlation between SEL1L-HRD1 ERAD functionality and disease severity in humans.
Denisa Weis, Liangguang Leo Lin, Huilun Helen Wang, Zexin Jason Li, Katarína Kušíková, Peter Ciznar, Hermann Maximillian Wolf, Alexander Leiss-Piller, Zhihong Wang, Xiaoqiong Wei, Serge Weis, Katarina Skalicka, Gabriela Hrckova, Lubos Danisovic, Andrea Soltysova, Tingxuan Tina Yang, René Günther Feichtinger, Johannes Adalbert Mayr, Ling Qi
Quentin McAfee, Matthew A. Caporizzo, Keita Uchida, Kenneth C. Bedi Jr., Kenneth B. Margulies, Zolt Arany, Benjamin L. Prosser
Mutations in the BRCA2 tumor suppressor gene have been associated with an increased risk of developing prostate cancer. One of the paradoxes concerning BRCA2 is the fact that its inactivation affects genetic stability and is deleterious for cellular and organismal survival, while BRCA2-mutated cancer cells adapt to this detriment and malignantly proliferate. Therapeutic strategies for tumors arising from BRCA2 mutations may be discovered by understanding these adaptive mechanisms. In this study, we conducted forward genetic synthetic viability screenings in C. elegans brc-2 (Cebrc-2) mutants and found that Ceubxn-2 inactivation rescued the viability of Cebrc-2 mutants. Moreover, loss of NSFL1C, the mammalian ortholog of CeUBXN-2, suppressed the spindle assembly checkpoint (SAC) activation and promoted the survival of BRCA2-deficient cells. Mechanistically, NSFL1C recruited USP9X to inhibit the polyubiquitination of AURKB and reduce the removal of AURKB from the centromeres by VCP, which is essential for SAC activation. SAC inactivation is common in BRCA2-deficient prostate cancer patients, but PP2A inhibitors could reactivate the SAC and achieve BRCA2-deficient prostate tumor synthetic lethality. Our research reveals the survival adaptation mechanism of BRCA2-deficient prostate tumor cells and provides different angles for exploring synthetic lethal inhibitors in addition to targeting DNA damage repair pathways.
Jian Wang, Yuke Chen, Shiwei Li, Wanchang Liu, Xiao Albert Zhou, Yefei Luo, Zhanzhan Xu, Yundong Xiong, Kaiqi Cheng, Mingjian Ruan, Wei Yu, Xiaoman Li, Weibin Wang, Jiadong Wang
Although most CD8+ T-cells are equipped to kill infected or transformed cells, a subset may regulate immune responses and preserve self-tolerance. Here we describe a CD8 lineage that is instructed to differentiate into CD8 T regulatory cells (Treg) by a surprisingly restricted set of T-cell receptors (TCR) that recognize MHC-E (mouse Qa-1) and several dominant self-peptides. Recognition and elimination of pathogenic target cells that express these Qa-1self-peptide complexes selectively inhibits pathogenic antibody responses without generalized immune suppression. Immunization with synthetic agonist peptides that mobilize CD8 Treg in vivo efficiently inhibit anti-graft antibody responses and markedly prolong heart and kidney organ graft survival. Definition of TCR-dependent differentiation and target recognition by this lineage of CD8 Treg may open the way to new therapeutic approaches to inhibit pathogenic antibody responses.
Hye-Jung Kim, Hidetoshi Nakagawa, John Y. Choi, Xuchun Che, Andrew Divris, Qingshi Liu, Andrew E. Wight, Hengcheng Zhang, Anis Saad, Zhabiz Solhjou, Christa Deban, Jamil R. Azzi, Harvey Cantor
BACKGROUND. PATRIOT was the first-in-human phase I study of the oral ATR (ataxia telangiectasia and Rad3-related) inhibitor ceralasertib (AZD6738) in advanced solid tumors. METHODS. Primary objective was safety. Secondary objectives included assessment of anti-tumor responses, pharmacokinetic (PK) and pharmacodynamic (PD) studies. Sixty-seven patients received ceralasertib 20-240 mg BD continuously or intermittently (14 of a 28-day cycle). RESULTS. Intermittent dosing was better tolerated than continuous, which was associated with dose-limiting hematological toxicity. The recommended phase 2 dose of ceralasertib was 160 mg twice daily for 2 weeks in a 4-weekly cycle. Modulation of target and increased DNA damage were identified in tumor and surrogate PD. There were 5 (8%) confirmed partial responses (PR, 40-240 mg BD), 34 (52%) stable disease (SD) including 1 unconfirmed partial response, and 27 (41%) progressive disease. Durable responses were seen in tumors with loss of AT-rich interactive domain-containing protein 1A (ARID1A) and DNA damage response defects. Treatment modulated tumor and systemic immune markers and responding tumors were more immune-inflamed than non-responding. CONCLUSION. Ceralasertib monotherapy was tolerated at 160 mg BD intermittent and associated with anti-tumor activity. TRIAL REGISTRATION. Clinicaltrials.gov: NCT02223923, EudraCT: 2013-003994-84. FUNDING. Cancer Research UK, AstraZeneca, UK Department of Health (National Institute for Health Research), Rosetrees Trust, Experimental Cancer Medicine Centre. FUNDING. AstraZeneca provided funding for components of the clinical conduct of PATRIOT and drug supply and labelling.
Magnus T. Dillon, Jeane Guevara, Kabir Mohammed, Emmanuel Christian Patin, Simon A. Smith, Emma Dean, Gemma N. Jones, Sophie E. Willis, Marcella Petrone, Carlos Silva, Khin Thway, Catey Bunce, Ioannis Roxanis, Pablo Nenclares, Anna Wilkins, Martin McLaughlin, Adoracion Jayme-Laiche, Sarah Benafif, Georgios Nintos, Vineet Kwatra, Lorna Grove, David C. Mansfield, Paula Proszek, Philip Martin, Luiza Moore, Karen E. Swales, Udai Banerji, Mark P. Saunders, James Spicer, Martin D. Forster, Kevin J. Harrington
Virophagy, the selective autophagosomal engulfment and lysosomal degradation of viral components, is crucial for neuronal cell survival and antiviral immunity. However, the mechanisms leading to viral antigen recognition and capture by autophagic machinery remain poorly understood. Here, we identified cyclin-dependent kinase-like 5 (CDKL5), known to function in neurodevelopment, as an essential regulator of virophagy. Loss of function mutations in CDKL5 are associated with a severe neurodevelopmental encephalopathy. We found deletion of CDKL5 or expression of a clinically-relevant pathogenic mutant of CDKL5 reduced virophagy of Sindbis virus (SINV), a neurotropic RNA virus, and increased intracellular accumulation of SINV capsid protein aggregates and cellular cytotoxicity. CDKL5 knockout mice displayed increased viral antigen accumulation and neuronal cell death after SINV infection and enhanced lethality after infection with several neurotropic viruses. Mechanistic studies demonstrated that CDKL5 directly binds the canonical selective autophagy receptor p62 and phosphorylates p62 at T269/S272 to promote its interaction with viral capsid aggregates. We found that CDKL5-mediated phosphorylation of p62 facilitated the formation of large p62 inclusion bodies that captured viral capsids to initiate capsid targeting to autophagic machinery. Overall, these findings identify a cell-autonomous innate immune mechanism for autophagy activation to clear intracellular toxic viral protein aggregates during infection.
Josephine W. Thinwa, Zhongju Zou, Emily Parks, Salwa Sebti, Kelvin K. Hui, Yongjie Wei, Mohammad Goodarzi, Vibha Singh, Greg Urquhart, Jenna L. Jewell, Julie K. Pfeiffer, Beth Levine, Tiffany A. Reese, Michael U. Shiloh
Even with the prolific clinical use of next-generation cancer therapeutics, many tumors remain unresponsive or become refractory to therapy, creating a medical need. In cancer, DCs are indispensable to T cell activation, so there is a restriction on cytotoxic T cell immunity if DCs are not present in sufficient numbers in the tumor and draining lymph nodes to uptake and present relevant cancer antigens. To address this bottleneck, we developed a Flt3L-based therapeutic named Alb-Flt3L that demonstrated superior pharmacokinetic properties compared to Flt3L, including significantly longer half-life, accumulation in tumor and lymph node, and cross-presenting DCs expansion following a single injection. We demonstrated that Alb-Flt3L, in combination with standard-of-care chemotherapy and radiation therapy, serves as an in situ vaccination strategy capable of engendering polyclonal tumor neoantigen-specific immunity spontaneously. In addition, Alb-Flt3L-mediated tumor control synergized with immune checkpoint blockade delivered as anti-PD-L1. The mechanism of action of Alb-Flt3L treatment revealed a dependency on Batf3, type-I-interferons, and plasmacytoid DCs. Finally, the ability of Alb-Flt3L to expand human DC was explored in humanized mice. We observed significant expansion of human cross-presenting DC subsets, supporting the notion that Alb-Flt3L could be used clinically to modulate human DC populations in future cancer therapeutic regimens.
Brandon Lam, Yu Jui Kung, John Lin, Ssu-Hsueh Tseng, Hsin-Fang Tu, Claire Huang, Brandon Lee, Esteban Velarde, Ya Chea Tsai, Rafael Villasmil, Sung Taek Park, Deyin Xing, Chien-Fu Hung, T.-C. Wu
Skull development coincides with the onset of cerebrospinal fluid (CSF) circulation, brain-CSF perfusion, and meningeal lymphangiogenesis, processes essential for brain waste clearance. How these processes are affected by craniofacial disorders such as craniosynostosis are poorly understood. We report that raised intracranial pressure and diminished CSF flow in craniosynostosis mouse models associates with pathological changes to meningeal lymphatic vessels that affect their sprouting, expansion, and long-term maintenance. We also show that craniosynostosis affects CSF circulatory pathways and perfusion into the brain. Further, craniosynostosis exacerbates amyloid pathology and plaque buildup in Twist1+/-:5xFAD transgenic Alzheimer’s disease models. Treating craniosynostosis mice with Yoda1, a small molecule agonist for Piezo1, reduces intracranial pressure and improves CSF flow, in addition to restoring meningeal lymphangiogenesis, drainage to the deep cervical lymph nodes, and brain-CSF perfusion. Leveraging these findings, we show Yoda1 treatments in aged mice with reduced CSF flow and turnover improve lymphatic networks, drainage, and brain-CSF perfusion. Our results suggest CSF provides mechanical force to facilitate meningeal lymphatic growth and maintenance. Additionally, applying Yoda1 agonist in conditions with raised intracranial pressure and/or diminished CSF flow, as seen in craniosynostosis or with ageing, is a possible therapeutic option to help restore meningeal lymphatic networks and brain-CSF perfusion.
Matt J. Matrongolo, Phillip S. Ang, Junbing Wu, Aditya Jain, Joshua K. Thackray, Akash G. Reddy, Chi Chang Sung, Gaetan Barbet, Young-Kwon Hong, Max A. Tischfield
ASXL1 mutation frequently occurs in all forms of myeloid malignancies and is associated with aggressive disease and poor prognosis. ASXL1 recruits Polycomb Repressive Complex 2 (PRC2) to specific gene loci to repress transcription through tri-methylation of histone H3 on lysine 27 (H3K27me3). ASXL1 alterations reduce H3K27me3 levels, which results in leukemogenic gene expression and the development of myeloid malignancies. Standard therapies for myeloid malignancies have limited efficacy when mutated ASXL1 is present. We discovered up-regulation of lysine demethylase 6B (KDM6B), a demethylase for H3K27me3, in ASXL1-mutant leukemic cells, which further reduces H3K27me3 levels and facilitates myeloid transformation. Here, we demonstrated that heterozygous deletion of Kdm6b restored H3K27me3 levels and normalized dysregulated gene expression in Asxl1Y588XTg hematopoietic stem/progenitor cells (HSPCs). Furthermore, heterozygous deletion of Kdm6b decreased the HSPC pool, restored their self-renewal capacity, prevented biased myeloid differentiation, and abrogated progression to myeloid malignancies in Asxl1Y588XTg mice. Importantly, administration of GSK-J4, a KDM6B inhibitor, not only restored H3K27me3 levels but also reduced the disease burden in NSG mice xenografted with human ASXL1 mutant leukemic cells in vivo. This preclinical finding provides compelling evidence that targeting KDM6B may be a therapeutic strategy for myeloid malignancies with ASXL1 mutations.
Guo Ge, Peng Zhang, Pinpin Sui, Shi Chen, Hui Yang, Ying Guo, Ivan P. Rubalcava, Asra Noor, Caroline R. Delma, Joel Agosto-Peña, Hui Geng, Edward A. Medina, Ying Liang, Stephen D. Nimer, Ruben Mesa, Omar Abdel-Wahab, Mingjiang Xu, Feng-Chun Yang
Feng Pan, Jolanda Sarno, Johan Jeong, Xin Yang, Astraea Jager, Tanja A. Gruber, Kara L. Davis, Michael L. Cleary
Hormone-receptor-positive breast cancer (HR+) is immunologically cold and has not benefited from advances in immunotherapy. In contrast, subsets of triple-negative breast cancer (TNBC) display high leukocytic infiltration and respond to checkpoint blockade. CD8+T cells, the main effectors of anti-cancer responses, recognize MHC I-associated peptides (MAPs). Our work aimed to characterize the repertoire of MAPs presented by HR+ and TNBC tumors. Using mass spectrometry, we identified 57,094 unique MAPs in 26 primary breast cancer samples. MAP source genes highly overlapped between both subtypes (>70%). We identified 25 tumor-specific antigens (TSAs) mainly deriving from aberrantly expressed regions. TSAs were most frequently identified in TNBC samples (70%) and were more shared among TCGA TNBC than HR+ samples. In the TNBC cohort, the predicted number of TSAs positively correlated with leukocytic infiltration (p<0.05) and overall survival (p<0.05), supporting their immunogenicity in vivo. We detected 49 tumor-associated antigens, some of which derived from cancer-associated fibroblasts. Functional expansion of specific T cell assays confirmed the in vitro immunogenicity of several TSAs and TAAs. Our study identified attractive targets for cancer immunotherapy in both breast cancer subtypes. The higher prevalence of TSAs in TNBC tumors provides a rationale for their responsiveness to checkpoint blockade.
Eralda Kina, Jean-Philippe Laverdure, Chantal Durette, Joël Lanoix, Mathieu Courcelles, Qingchuan Zhao, Anca Apavaloaei, Jean-David Larouche, Marie-Pierre Hardy, Krystel Vincent, Patrick Gendron, Leslie Hesnard, Catherine Thériault, Maria Virginia Ruiz Cuevas, Grégory Ehx, Pierre Thibault, Claude Perreault
Mineralocorticoid excess commonly leads to hypertension and kidney disease. In our study, we employed single-cell expression and chromatin accessibility tools to characterize the mineralocorticoid target genes and cell types. We demonstrated that mineralocorticoid effects are established through open chromatin and target gene expression, primarily in principal and connecting tubule cells, and to a lesser extent, in segments of the distal convoluted tubule cells. We examined the kidney-protective effects of steroidal and non-steroidal mineralocorticoid antagonists (MRAs), as well as amiloride, an epithelial sodium channel inhibitor, in a rat model of deoxycorticosterone acetate, unilateral nephrectomy, and high salt consumption-induced hypertension and cardiorenal damage. All antihypertensive therapies protected from cardiorenal damage. However, finerenone was particularly effective in reducing albuminuria and improving gene expression changes in podocytes and proximal tubule cells, even with equivalent blood pressure reduction. There was a strong correlation between the accumulation of injured/profibrotic tubule cells expressing Spp1, Il34, and Pdgfb and the degree of fibrosis in rat kidneys. This gene signature also showed potential for classifying human kidney samples. Our multi-omics approach provides fresh insights into the possible mechanisms underlying hypertension associated kidney disease, the target cell types, and the protective effects of steroidal, non-steroidal MRAs, and amiloride.
Amin Abedini, Andrea Sanchez-Navarro, Junnan Wu, Konstantin A. Klötzer, Ziyuan Ma, Bibek Poudel, Tomohito Doke, Michael S. Balzer, Julia Frederick, Hana Cernecka, Hongbo Liu, Xiujie Liang, Steven Vitale, Peter Kolkhof, Katalin Susztak
Several poly (ADP-ribose) polymerase (PARP) inhibitors (PARPi) are approved by FDA treat cancer with BRCA mutations. BRCA mutation is considered to fuel PARPi killing effect by inducing apoptosis. However, resistance to PARPi is frequently observed in clinic due to incomplete understanding on the molecular basis of PARPi function and lack of good markers to predict response in addition to BRCA mutations. Here we show that gasdermin C (GSDMC) sensitized tumor cells to PARPi in vitro and in immunocompetent mice and caused durable tumor regression in an immune-dependent manner. High expression level of GSDMC predicted better response to PARPi treatment in triple-negative breast cancer (TNBC) patients. PARPi treatment triggered GSDMC/caspase-8-mediated cancer cell pyroptosis (CCP) that enhanced PARPi killing of tumor cells. GSDMC-mediated CCP increased memory CD8+ T cell population in lymph node (LN), spleen, tumor, and thus promoted cytotoxic CD8+ T cell infiltration in tumor microenvironment. T cell-derived granzyme B (GZMB) activated caspase-6, which subsequently cleaved GSDMC to induce pyroptosis. Interestingly, IFN-γ induced GSDMC expression, which in turn enhanced the cytotoxicity of PARPi and T cell. Importantly, GSDMC promoted tumor clearance independent of BRCA deficiency in multiple cancer types with PARPi treatment. This study identifies a general marker and target for PARPi therapy and offers new insights into the mechanism of PARPi function.
Shuanglian Wang, Chiung-Wen Chang, Juan Huang, Shan Zeng, Xin Zhang, Mien-Chie Hung, Junwei Hou
Garth T. Whiteside, Donald J. Kyle, Ram P. Kapil, Alessandra Cipriano, Ellie He, Mingyan Zhou, Manjunath S. Shet, Michele Hummel, Terri Knappenberger, Kazuya Fukumura, Yoshiyuki Matsuo, Masahiro Uehira, Shuichi Hiroyama, Nozomi Takai, Sandra K. Willsie, Stephen C. Harris
Physiologic activation of the estrogen receptor alpha (ERα) is mediated by estradiol (E2) binding in the ligand binding pocket of the receptor, repositioning helix 12 (H12) to facilitate binding of coactivator proteins in the unoccupied coactivator binding groove. In breast cancer, activation of ERα is often observed through point mutations that lead to the same H12 repositioning in the absence of E2. Through expanded genetic sequencing of breast cancer patients, we identified a collection of mutations located far from H12 but nonetheless capable of promoting E2-independent transcription and breast cancer cell growth. Using machine learning and computational structure analyses, this set of mutants was inferred to act distinctly from the H12-repositioning mutants and instead was associated with conformational changes across the ERα dimer interface. Through both in vitro and in cell assays of full length ERα protein and isolated ligand binding domain (LBD), we found that these mutants promoted ERα dimerization, stability, and nuclear localization. Point mutations that selectively disrupted dimerization abrogated E2-independent transcriptional activity of these dimer-promoting mutants. The results revealed a distinct mechanism for activation of ERα function through enforced receptor dimerization and suggested dimer disruption as a potential therapeutic strategy to treat ER-dependent cancers.
Seema Irani, Wuwei Tan, Qing Li, Weiyi Toy, Catherine Jones, Mayur Gadiya, Antonio Marra, John A. Katzenellenbogen, Kathryn E. Carlson, Benita S. Katzenellenbogen, Mostafa Karimi, Ramya Segu Rajappachetty, Isabella S. Del Priore, Jorge S. Reis-Filho, Yang Shen, Sarat Chandarlapaty
BACKGROUND. In the Lewy body diseases (LBDs) Parkinson’s disease (PD) and dementia with Lewy bodies (DLB), by the time parkinsonism or cognitive dysfunction manifests clinically substantial neurodegeneration has already occurred. Biomarkers are needed to identify central LBDs in a preclinical phase, when neurorescue strategies might forestall symptomatic disease. This phase may involve catecholamine deficiency in the autonomic nervous system. We analyzed data from the prospective, observational, long-term PDRisk study to assess the predictive value of low vs. normal cardiac 18F-dopamine positron emission tomography (PET), an index of myocardial content of the sympathetic neurotransmitter norepinephrine, in at-risk individuals. METHODS. Participants self-reported risk factor information (genetics, olfactory dysfunction, dream enactment behavior, orthostatic intolerance or hypotension) at a protocol-specific website. Thirty-four with ≥ 3 confirmed risk factors underwent serial cardiac 18F-dopamine PET at 1.5-yearly intervals for up to 7.5 years or until PD was diagnosed. RESULTS. Nine participants had low initial myocardial 18F-dopamine-derived radioactivity (<6,000 nCi-kg/cc-Ci) and 25 normal radioactivity. At 7 years of follow-up, 8 of 9 with low initial radioactivity and 1 of 11 with normal radioactivity were diagnosed with a central LBD (LBD+) (P = 0.0009 by Fisher's exact test). Conversely, all of 9 LBD+ participants had low 18F-dopamine-derived radioactivity before or at the time of diagnosis of a central LBD, whereas among 25 participants without a central LBD only 1 (4%) had persistently low radioactivity (P < 0.0001 by Fisher’s exact test). CONCLUSIONS. Cardiac 18F-dopamine PET highly efficiently distinguishes at-risk individuals who are diagnosed subsequently with a central LBD from those who are not.
David S. Goldstein, Courtney Holmes, Patti Sullivan, Grisel Lopez, Janna Gelsomino, Sarah Moore, Risa Isonaka, Tianxia Wu, Yehonatan Sharabi
We have previously demonstrated that cystatin E/M (CST6), elevated in a subset of multiple myeloma (MM) patients lacking osteolytic lesions (OL), suppresses MM bone disease by blocking osteoclast differentiation and function. CST6 is a secreted type 2 cystatin, a cysteine protease inhibitor that regulates lysosomal cysteine proteases and the asparaginyl endopeptidase legumain. We have developed B cell maturation antigen (BCMA)-CST6-chimeric antigen receptor (CAR) T cells, which lyse MM cells and release CST6 proteins. Our in vitro studies show that these CAR-T cells suppress differentiation and formation of tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts. Using xenografted MM mice, bioluminescence images show that both BCMA-CAR-T and BCMA-CST6-CAR-T cells inhibit MM growth to a similar extent. Reconstructed micro-computed tomography (µCT) images reveal that BCMA-CST6-CAR-T cells, but not BCMA-CAR-T cells, prevent MM-induced bone damage and decrease osteoclast numbers. Our results provide a CAR-T strategy that targets tumor cells directly and delivers an inhibitor of bone resorption.
Fumou Sun, Yan Cheng, Jin-Ran Chen, Visanu Wanchai, David E. Mery, Hongwei Xu, Dongzheng Gai, Samer Al Hadidi, Carolina Schinke, Sharmilan Thanendrarajan, Maurizio Zangari, Frits van Rhee, Guido Tricot, John D. Shaughnessy Jr., Fenghuang Zhan
Protein synthesis is frequently dysregulated in cancer and selective inhibition of mRNA translation represents an attractive cancer therapy. Here, we show that therapeutically targeting the RNA helicase eIF4A by Zotatifin, the first-in-class eIF4A inhibitor, exerts pleiotropic effects on both tumor cells and the tumor immune microenvironment in a diverse cohort of syngeneic triple-negative breast cancer (TNBC) mouse models. Zotatifin not only suppresses tumor cell proliferation but also directly repolarizes macrophages towards an M1-like phenotype and inhibits neutrophil infiltration, which sensitizes tumors to immune checkpoint blockade. Mechanistic studies revealed that Zotatifin reprograms the tumor translational landscape, inhibits the translation of Sox4 and Fgfr1, and induces an interferon response uniformly across models. The induction of an interferon response is partially due to the inhibition of Sox4 translation by Zotatifin. A similar induction of interferon-stimulated genes was observed in breast cancer patient biopsies following Zotatifin treatment. Surprisingly, Zotatifin significantly synergizes with carboplatin to trigger DNA damage and an even heightened interferon response resulting in T cell-dependent tumor suppression. These studies identified a vulnerability of eIF4A in TNBC, potential pharmacodynamic biomarkers for Zotatifin, and provide a rationale for new combination regimens comprising Zotatifin and chemotherapy or immunotherapy as treatments for TNBC.
Na Zhao, Elena B. Kabotyanski, Alexander B. Saltzman, Anna Malovannaya, Xueying Yuan, Lucas C. Reineke, Nadia Lieu, Yang Gao, Diego A. Pedroza, Sebastian J. Calderon, Alex J. Smith, Clark W. Hamor, Kazem Safari, Sara R. Savage, Bing Zhang, Jianling Zhou, Luisa M. Solis Soto, Susan G. Hilsenbeck, Cheng Fan, Charles M. Perou, Jeffrey M. Rosen