[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-374698-105":59,"doc-detail-374698-en":130},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":123,"head_meta":125,"extra_data":127,"updated_unix":129},105,"en","ap4a-in-cancer-a-multifaceted-regulator-and-emerging-therapeutic-target-review","Ap4A in Cancer - A Multifaceted Regulator and Emerging Therapeutic Target - Review","","Diadenosine polyphosphates, including diadenosine tetraphosphate (Ap4A), are ubiquitous nucleotides functioning as cellular signaling molecules across diverse life forms. This review synthesizes current evidence on Ap4A biosynthesis and degradation, identifies Ap4A protein targets, and explains key mechanisms of its action. It examines how pathogenetic processes driving tumor development intersect with Ap4A-mediated stress responses, positioning Ap4A at the nexus of cancer adaptation and progression.",{"@graph":69,"@context":122},[70,84,105],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":35,"@type":76,"position":81},"https://docshare.wps.com/document/healthcare/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/ap4a-in-cancer-a-multifaceted-regulator-and-emerging-therapeutic-target-review/374698/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/ap4a-in-cancer-a-multifaceted-regulator-and-emerging-therapeutic-target-review/374698.png","ImageObject",300,407,{"name":92,"@type":93},"Stanley","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-29","2026-09-23",true,{"@type":102,"interactionType":103,"userInteractionCount":19},"InteractionCounter",{"@type":104},"ViewAction",{"@type":106,"mainEntity":107},"FAQPage",[108,114,118],{"name":109,"@type":110,"acceptedAnswer":111},"What biological processes does Ap4A regulate in cancer-related contexts?","Question",{"text":112,"@type":113},"Ap4A is described as a stress signal that contributes to tumor cell adaptation and survival, including regulation of proliferation, survival, and gene expression under hostile conditions.","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"How does the review characterize Ap4A at the molecular level?",{"text":117,"@type":113},"It summarizes Ap4A biosynthesis and degradation pathways, outlines identification of Ap4A protein targets, and discusses molecular mechanisms underlying its signaling actions.",{"name":119,"@type":110,"acceptedAnswer":120},"What other physiological roles does Ap4A have besides cancer?",{"text":121,"@type":113},"The review reports Ap4A involvement in platelet-associated release and cardiovascular regulation, including vasodilation via nitric oxide and prostacyclin, as well as modulation of purinergic signaling.","https://schema.org",{"og:url":83,"og:type":124,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":126,"canonical":83},"index,follow",{"doc_id":128,"site_id":62},374698,1792201654,{"code":4,"msg":5,"data":131},{"doc_id":128,"user_id":132,"nickname":92,"user_avatar":133,"doc_module":4,"category_id":34,"category_name":35,"doc_title":65,"doc_description":67,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":19,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":139,"language":140,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":141,"faqs":142,"seo_title":143,"seo_description":67,"update_tm":144,"read_time":145},2336477405376,"https://ap-avatar.wpscdn.com/davatar_29158cc5080c5b710cf443261637dec0","Review  \nAp4A in Cancer: A Multifaceted Regulator and Emerging Therapeutic Target  \nKateryna Tkachenko , Tiziana Bachetti and Camillo Rosano *  \nAcademic Editor: AkinoriKuzuya  \nReceived: 28 April 2025  \nRevised: 7 July 2025  \nAccepted: 17 July 2025  \nPublished: 22 July 2025  \nCitation: Tkachenko, K.; Bachetti, T.;  \nRosano, C. Ap4Ain Cancer: A Multifaceted Regulator and Emerging Therapeutic Target. Molecules 2025, 30, 3056. [https://doi.org/10.3390/](https://doi.org/10.3390/)[ ](https://doi.org/10.3390/)molecules30153056  \nCopyright: © 2025 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ([https://creativecommons.org/](https://creativecommons.org/)[ ](https://creativecommons.org/)[licenses/by/4.0/](licenses/by/4.0/)) .  \nProteomics and Mass Spectrometry Unit, IRCSS Ospedale Policlinico San Martino, 16132 Genova, Italy;  \n[kateryna.tkachenko@hsanmartino.it](kateryna.tkachenko@hsanmartino.it) (K.T.); [tiziana.bachetti@hsanmartino.it](tiziana.bachetti@hsanmartino.it) (T.B.)  \n* Correspondence: [camillo.rosano@hsanmartino.it](camillo.rosano@hsanmartino.it)  \nAbstract  \nDiadenosine polyphosphates, including diadenosine tetraphosphate (Ap4A), are ubiquitous nucleotides that are present across diverse life forms, gaining considerable interest due to their role as cellular signaling molecules. Ap4A, in particular, has been extensively researched in various biological systems, especially under conditions of environmental stress. This review provides an in-depth analysis of the current knowledge surrounding Ap4A, focusing on its biosynthesis and degradation pathways, the identification of Ap4A protein targets and the molecular mechanisms underlying its action. Furthermore, this review aims to examine the interplay between the various pathogenetic mechanisms driving tumor development and the potential role of Ap4A which emerges as pivotal signaling molecules orchestrating cellular responses to environmental challenges, positioning them at the nexus of cancer adaptation and progression.  \nKeywords: diadenosine tetraphosphate; cancer; cellular process  \n1. Introduction  \nIn the intricate landscape of tumor biology, cancer cells are continually exposed to a variety of intrinsic and extrinsic stressors, including hypoxia, nutrient deprivation, oxidative damage, and immune surveillance. To survive and thrive under these hostile conditions, tumor cells develop sophisticated adaptive strategies that involve dynamic reprogramming of both metabolic and transcriptional processes. One such adaptation involves the use of molecular “alarmones”—small signaling nucleotides that enable rapid cellular responses to stress. Among these, diadenosine tetraphosphate (Ap4A) has emerged as a compelling candidate. First discovered in 1966, Ap4A was long considered a metabolic by-product; however, it is now recognized as a potent stress signal involved in diverse physiological and pathological processes. Much like bacterial alarmones such as guanosine tetraphosphate (ppGpp), which orchestrate wide-ranging adjustments to cellular activity during nutrient stress, Ap4A has been shown to regulate proliferation, survival, and gene expression in mammalian cells [1] .  \nAp4A functions as both a signaling molecule and a regulator of cellular homeostasis, particularly under stress [2] . It is tightly regulated within cells and can accumulate in response to stressors, triggering protective mechanisms to preserve cellular integrity [3] . Early studies demonstrated that Ap4A levels vary significantly across mammalian cell lines, with higher levels observed in rapidly proliferating cells and an inverse correlation with doubling time—indicating its potential role as a metabolic signal linked to cell growth and division [4] .  \nOne of Ap4A’s central roles lies in the regulation of the cell cycle. By interacting with key proteins, it influence","cbCairTkSAn0rrlq","https://ap.wps.com/l/cbCairTkSAn0rrlq","pdf",1032314,22,"English","# Abstract\n# 1. Introduction\n## Tumor stressors and adaptive strategies\n## Ap4A as a stress signal and alarmone\n## Roles in cell cycle regulation\n## Ap4A in tumor progression and survival\n## Ap4A functions beyond cancer (cardiovascular and inflammation)","[{\"question\":\"What biological processes does Ap4A regulate in cancer-related contexts?\",\"answer\":\"Ap4A is described as a stress signal that contributes to tumor cell adaptation and survival, including regulation of proliferation, survival, and gene expression under hostile conditions.\"},{\"question\":\"How does the review characterize Ap4A at the molecular level?\",\"answer\":\"It summarizes Ap4A biosynthesis and degradation pathways, outlines identification of Ap4A protein targets, and discusses molecular mechanisms underlying its signaling actions.\"},{\"question\":\"What other physiological roles does Ap4A have besides cancer?\",\"answer\":\"The review reports Ap4A involvement in platelet-associated release and cardiovascular regulation, including vasodilation via nitric oxide and prostacyclin, as well as modulation of purinergic signaling.\"}]","Ap4A in Cancer - A Multifaceted Regulator and Emerging Therapeutic Target - Review | PDF",1790202202,55]