Lactate receptor GPR81 drives breast cancer growth and invasiveness through regulation of ECM properties and Notch ligand DLL4

Kathrine Lundø, Oksana Dmytriyeva, Louise Spøhr, Eliana Goncalves-Alves, Jiayi Yao, Laia P. Blasco, Mette Trauelsen, Muthulakshmi Ponniah, Marc Severin, Albin Sandelin, Marie Kveiborg, Thue W. Schwartz*, Stine F. Pedersen

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

2 Citations (Scopus)
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Abstract

Background: The lactate receptor GPR81 contributes to cancer development through unclear mechanisms. Here, we investigate the roles of GPR81 in three-dimensional (3D) and in vivo growth of breast cancer cells and study the molecular mechanisms involved. Methods: GPR81 was stably knocked down (KD) in MCF-7 human breast cancer cells which were subjected to RNA-seq analysis, 3D growth, in situ- and immunofluorescence analyses, and cell viability- and motility assays, combined with KD of key GPR81-regulated genes. Key findings were additionally studied in other breast cancer cell lines and in mammary epithelial cells. Results: GPR81 was upregulated in multiple human cancer types and further upregulated by extracellular lactate and 3D growth in breast cancer spheroids. GPR81 KD increased spheroid necrosis, reduced invasion and in vivo tumor growth, and altered expression of genes related to GO/KEGG terms extracellular matrix, cell adhesion, and Notch signaling. Single cell in situ analysis of MCF-7 cells revealed that several GPR81-regulated genes were upregulated in the same cell clusters. Notch signaling, particularly the Notch ligand Delta-like-4 (DLL4), was strikingly downregulated upon GPR81 KD, and DLL4 KD elicited spheroid necrosis and inhibited invasion in a manner similar to GPR81 KD. Conclusions: GPR81 supports breast cancer aggressiveness, and in MCF-7 cells, this occurs at least in part via DLL4. Our findings reveal a new GPR81-driven mechanism in breast cancer and substantiate GPR81 as a promising treatment target.

Original languageEnglish
Article number1136
JournalBMC Cancer
Volume23
Issue number1
Number of pages20
ISSN1471-2407
DOIs
Publication statusPublished - 2023

Bibliographical note

Publisher Copyright:
© 2023, The Author(s).

Keywords

  • EPHA7
  • Extracellular matrix
  • HCAR1
  • Metabolite GPCR
  • Notch
  • PCDH7
  • Spheroid
  • Tumor microenvironment

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