ANGPTL2+cancer-associated fibroblasts and SPP1+macrophages are metastasis accelerators of colorectal cancer

Front Immunol. 2023 Aug 24:14:1185208. doi: 10.3389/fimmu.2023.1185208. eCollection 2023.

Abstract

Background: Liver metastasis (LM) is a leading cause of cancer-related deaths in CRC patients, whereas the associated mechanisms have not yet been fully elucidated. Therefore, it is urgently needed to deeply explore novel metastasis accelerators and therapeutic targets of LM-CRC.

Methods: The bulk RNA sequencing data and clinicopathological information of CRC patients were enrolled from the TCGA and GEO databases. The single-cell RNA sequencing (scRNA-seq) datasets of CRC were collected from and analyzed in the Tumor Immune Single-cell Hub (TISCH) database. The infiltration levels of cancer-associated fibroblasts (CAFs) and macrophages in CRC tissues were estimated by multiple immune deconvolution algorithms. The prognostic values of genes were identified by the Kaplan-Meier curve with a log-rank test. GSEA analysis was carried out to annotate the significantly enriched gene sets. The biological functions of cells were experimentally verified.

Results: In the present study, hundreds of differentially expressed genes (DEGs) were selected in LM-CRC compared to primary CRC, and these DEGs were significantly associated with the regulation of endopeptidase activity, blood coagulation, and metabolic processes. Then, SPP1, CAV1, ANGPTL2, and COLEC11 were identified as the characteristic DEGs of LM-CRC, and higher expression levels of SPP1 and ANGPTL2 were significantly associated with worse clinical outcomes of CRC patients. In addition, ANGPTL2 and SPP1 mainly distributed in the tumor microenvironment (TME) of CRC tissues. Subsequent scRNA-seq analysis demonstrated that ANGPTL2 and SPP1 were markedly enriched in the CAFs and macrophages of CRC tissues, respectively. Moreover, we identified the significantly enriched gene sets in LM-CRC, especially those in the SPP1+macrophages and ANGPTL2+CAFs, such as the HALLMARK_EPITHELIAL_MESENCHYMAL_TRANSITION and the HALLMARK_COMPLEMENT. Finally, our in vitro experiments proved that ANGPTL2+CAFs and SPP1+macrophages promote the metastasis of CRC cells.

Conclusion: Our study selected four characteristic genes of LM-CRC and identified ANGPTL2+CAFs and SPP1+macrophages subtypes as metastasis accelerators of CRC which provided a potential therapeutic target for LM-CRC.

Keywords: cancer-associated fibroblast; colorectal cancer; liver metastasis; macrophage; single-cell RNA sequencing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • Angiopoietin-Like Protein 2
  • Cancer-Associated Fibroblasts*
  • Colorectal Neoplasms* / genetics
  • Colorectal Neoplasms* / pathology
  • Humans
  • Liver Neoplasms* / genetics
  • Liver Neoplasms* / secondary
  • Macrophages
  • Osteopontin
  • Tumor Microenvironment / genetics

Substances

  • Angiopoietin-Like Protein 2
  • ANGPTL2 protein, human
  • Osteopontin
  • SPP1 protein, human

Grants and funding

This work was supported by grants from the National Natural Science Foundation of China (Grant No. 82272629), Jiangsu Provincial Medical Key Discipline Cultivation Unit (JSDW202239), Key Project of Science and Technology Development of Nanjing Medicine (ZKX21042), the research project of Jiangsu Health Development Research Center (JSHD2022057), Elderly Health Research Project of Jiangsu Province (Grant No. LR2021017), Specialized Cohort Research Project of Nanjing Medical University (NMUC2021013A).