{"title":"RNA-binding protein LSM7 facilitates breast cancer metastasis through mediating alternative splicing of CD44","authors":"","doi":"10.1016/j.lfs.2024.123013","DOIUrl":null,"url":null,"abstract":"<div><h3>Aims</h3><p>The RNA-binding protein LSM7 is essential for RNA splicing, acting as a key component of the spliceosome complex; however, its specific role in breast cancer (BC) has not been extensively investigated.</p></div><div><h3>Materials and methods</h3><p>LSM7 expression in BC samples was evaluated through bioinformatics analysis and immunohistochemistry. The impact of LSM7 on promoting metastatic tumor characteristics was examined using transwell and wound healing assays, as well as an orthotopic xenograft model. Additionally, the involvement of LSM7 in alternative splicing of CD44 was explored via RNA immunoprecipitation and third-generation sequencing. The regulatory role of TCF3 in modulating LSM7 gene expression was further elucidated using luciferase reporter assays and chromatin immunoprecipitation.</p></div><div><h3>Key findings</h3><p>Our findings demonstrate that LSM7 was significantly overexpressed in metastatic BC tissues and was associated with poor prognostic outcomes in patients with BC. LSM7 overexpression markedly increased the migratory and invasive capabilities of BC cells <em>in vitro</em> and significantly promoted spontaneous lung metastasis <em>in vivo</em>. Furthermore, RIP-seq analysis revealed that LSM7 binded to CD44 RNA, enhancing the expression of its alternatively spliced isoform CD44s, thereby driving BC metastasis and invasion. Additionally, the transcription factor TCF3 was found to activate LSM7 transcription by directly binding to its promoter.</p></div><div><h3>Significance</h3><p>In summary, this study highlights the pivotal role of LSM7 in the production of the CD44s isoform and the promotion of breast cancer metastasis. Targeting the TCF3/LSM7/CD44s axis may offer a promising therapeutic strategy for breast cancer treatment.</p></div>","PeriodicalId":18122,"journal":{"name":"Life sciences","volume":null,"pages":null},"PeriodicalIF":5.2000,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0024320524006039/pdfft?md5=a1a7996e9bbf21215a36c33f7fdd53a4&pid=1-s2.0-S0024320524006039-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Life sciences","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0024320524006039","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MEDICINE, RESEARCH & EXPERIMENTAL","Score":null,"Total":0}
引用次数: 0
Abstract
Aims
The RNA-binding protein LSM7 is essential for RNA splicing, acting as a key component of the spliceosome complex; however, its specific role in breast cancer (BC) has not been extensively investigated.
Materials and methods
LSM7 expression in BC samples was evaluated through bioinformatics analysis and immunohistochemistry. The impact of LSM7 on promoting metastatic tumor characteristics was examined using transwell and wound healing assays, as well as an orthotopic xenograft model. Additionally, the involvement of LSM7 in alternative splicing of CD44 was explored via RNA immunoprecipitation and third-generation sequencing. The regulatory role of TCF3 in modulating LSM7 gene expression was further elucidated using luciferase reporter assays and chromatin immunoprecipitation.
Key findings
Our findings demonstrate that LSM7 was significantly overexpressed in metastatic BC tissues and was associated with poor prognostic outcomes in patients with BC. LSM7 overexpression markedly increased the migratory and invasive capabilities of BC cells in vitro and significantly promoted spontaneous lung metastasis in vivo. Furthermore, RIP-seq analysis revealed that LSM7 binded to CD44 RNA, enhancing the expression of its alternatively spliced isoform CD44s, thereby driving BC metastasis and invasion. Additionally, the transcription factor TCF3 was found to activate LSM7 transcription by directly binding to its promoter.
Significance
In summary, this study highlights the pivotal role of LSM7 in the production of the CD44s isoform and the promotion of breast cancer metastasis. Targeting the TCF3/LSM7/CD44s axis may offer a promising therapeutic strategy for breast cancer treatment.
期刊介绍:
Life Sciences is an international journal publishing articles that emphasize the molecular, cellular, and functional basis of therapy. The journal emphasizes the understanding of mechanism that is relevant to all aspects of human disease and translation to patients. All articles are rigorously reviewed.
The Journal favors publication of full-length papers where modern scientific technologies are used to explain molecular, cellular and physiological mechanisms. Articles that merely report observations are rarely accepted. Recommendations from the Declaration of Helsinki or NIH guidelines for care and use of laboratory animals must be adhered to. Articles should be written at a level accessible to readers who are non-specialists in the topic of the article themselves, but who are interested in the research. The Journal welcomes reviews on topics of wide interest to investigators in the life sciences. We particularly encourage submission of brief, focused reviews containing high-quality artwork and require the use of mechanistic summary diagrams.