Ryotaro Kawasumi, Rubaiat E Tabassum, Kouji Hirota
Conventional cancer therapies, including radiation therapy and chemotherapy, rely on inflicting DNA damage, yet they inevitably affect normal cells, leading to severe adverse effects. The advent of precision chemotherapy exploiting tumor-specific DNA repair defects has validated the effectiveness of this approach. The first successful example is PARP inhibitors, which selectively kill homologous recombination (HR) defective cancers, such as familial breast cancer possessing HR deficiency due to BRCA gene mutations. However, the broader landscape of DNA maintenance-including DNA replication, repair, and checkpoint pathways-harbors numerous mutations in tumors that remain untargeted. Here, we propose repurposing chain-terminating nucleoside analogs (CTNAs) to target such cancers' vulnerabilities. CTNAs, long utilized as anti-cancers and anti-viral drugs, inhibit replication and thereby suppress growth, but their activity has never been systematically aligned with specific cancer mutations associated with DNA maintenance defects. Based on our recent studies, we demonstrate that CTNAs elicit synthetic lethality in cells deficient for distinct DNA maintenance systems, amplifying replication stress, leading to cell death. We highlight the spectrum of CTNA-induced lesions and repair pathways required for cellular tolerance. This framework presents a versatile "repair-defect-guided" chemotherapy that expands the clinical utility of CTNAs and improves therapeutic effect by reducing side effects.
{"title":"Targeting Genome Maintenance Defects of Cancers Using Chain-Terminating Nucleoside Analogs.","authors":"Ryotaro Kawasumi, Rubaiat E Tabassum, Kouji Hirota","doi":"10.1111/cas.70285","DOIUrl":"https://doi.org/10.1111/cas.70285","url":null,"abstract":"<p><p>Conventional cancer therapies, including radiation therapy and chemotherapy, rely on inflicting DNA damage, yet they inevitably affect normal cells, leading to severe adverse effects. The advent of precision chemotherapy exploiting tumor-specific DNA repair defects has validated the effectiveness of this approach. The first successful example is PARP inhibitors, which selectively kill homologous recombination (HR) defective cancers, such as familial breast cancer possessing HR deficiency due to BRCA gene mutations. However, the broader landscape of DNA maintenance-including DNA replication, repair, and checkpoint pathways-harbors numerous mutations in tumors that remain untargeted. Here, we propose repurposing chain-terminating nucleoside analogs (CTNAs) to target such cancers' vulnerabilities. CTNAs, long utilized as anti-cancers and anti-viral drugs, inhibit replication and thereby suppress growth, but their activity has never been systematically aligned with specific cancer mutations associated with DNA maintenance defects. Based on our recent studies, we demonstrate that CTNAs elicit synthetic lethality in cells deficient for distinct DNA maintenance systems, amplifying replication stress, leading to cell death. We highlight the spectrum of CTNA-induced lesions and repair pathways required for cellular tolerance. This framework presents a versatile \"repair-defect-guided\" chemotherapy that expands the clinical utility of CTNAs and improves therapeutic effect by reducing side effects.</p>","PeriodicalId":48943,"journal":{"name":"Cancer Science","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145726714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Succinylation has been shown to promote lung cancer development, but its mechanism remains incompletely understood. KAT2A, a succinyltransferase, acts as an oncogene in multiple cancers, but its role in mediating lung cancer progression is unclear. This study aimed to investigate the mechanism by which KAT2A regulates lung cancer progression via succinylation. KAT2A expression was analyzed using UALCAN, GEPIA, and Kaplan-Meier Plotter databases, and validated in lung cancer cell lines and patient-derived tissues. Quantitative real-time PCR, Cell Counting Kit-8 (CCK-8), EdU staining, and flow cytometry were performed to assess KAT2A's role in lung cancer cell proliferation and apoptosis. KAT2A's target proteins were predicted using LinkedOmics and STRING databases. Additionally, in vivo xenograft models were established to evaluate the effect of KAT2A knockdown on tumor growth. Results indicated that KAT2A expression was significantly elevated in lung cancer cells and tissues and was associated with poor prognosis. KAT2A knockdown inhibited proliferation and promoted apoptosis in lung cancer cells, whereas MYC overexpression reversed these effects. Mechanistically, KAT2A knockdown downregulated MYC by reducing succinylation at K370 and K386 residues. Mutation of these sites abrogated the proliferative effect of MYC overexpression and restored apoptotic activity. Furthermore, in vivo experiments demonstrated that KAT2A knockdown inhibited tumor growth and reduced MYC succinylation. Our findings demonstrate that KAT2A functions as an oncogene in lung cancer by enhancing MYC succinylation. This study identifies KAT2A as a promising therapeutic target for lung cancer.
{"title":"KAT2A Deficiency Suppresses Lung Cancer Progression by Downregulating MYC Through Decreasing MYC Succinylation.","authors":"Junping Li, Feng Zhao, Zhongchao Wang, Shaojun Yang, Zhichao Lu, Xiaoyan Li, Jincheng Song, Zhaoxia Dai","doi":"10.1111/cas.70286","DOIUrl":"https://doi.org/10.1111/cas.70286","url":null,"abstract":"<p><p>Succinylation has been shown to promote lung cancer development, but its mechanism remains incompletely understood. KAT2A, a succinyltransferase, acts as an oncogene in multiple cancers, but its role in mediating lung cancer progression is unclear. This study aimed to investigate the mechanism by which KAT2A regulates lung cancer progression via succinylation. KAT2A expression was analyzed using UALCAN, GEPIA, and Kaplan-Meier Plotter databases, and validated in lung cancer cell lines and patient-derived tissues. Quantitative real-time PCR, Cell Counting Kit-8 (CCK-8), EdU staining, and flow cytometry were performed to assess KAT2A's role in lung cancer cell proliferation and apoptosis. KAT2A's target proteins were predicted using LinkedOmics and STRING databases. Additionally, in vivo xenograft models were established to evaluate the effect of KAT2A knockdown on tumor growth. Results indicated that KAT2A expression was significantly elevated in lung cancer cells and tissues and was associated with poor prognosis. KAT2A knockdown inhibited proliferation and promoted apoptosis in lung cancer cells, whereas MYC overexpression reversed these effects. Mechanistically, KAT2A knockdown downregulated MYC by reducing succinylation at K370 and K386 residues. Mutation of these sites abrogated the proliferative effect of MYC overexpression and restored apoptotic activity. Furthermore, in vivo experiments demonstrated that KAT2A knockdown inhibited tumor growth and reduced MYC succinylation. Our findings demonstrate that KAT2A functions as an oncogene in lung cancer by enhancing MYC succinylation. This study identifies KAT2A as a promising therapeutic target for lung cancer.</p>","PeriodicalId":48943,"journal":{"name":"Cancer Science","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145709152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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