The Stemness-High Human Colorectal Cancer Cells Promote Angiogenesis by Producing Higher Amounts of Angiogenic Cytokines via Activation of the Egfr/Akt/Nf-κB Pathway

Int J Mol Sci. 2021 Jan 29;22(3):1355. doi: 10.3390/ijms22031355.

Abstract

Purpose: Cancer stem cells (CSCs) are responsible for cancer metastasis by stimulating tumor angiogenesis via various mechanisms. To elucidate the potential of the stemness-high human colorectal cancer (CRC) cells (i.e., CRCSCs) in activating angiogenesis, effects of the GATA6-overexpressing HCT-116 and HT-29 human CRC clones established previously by us in promoting the angiogenesis of human umbilical vein endothelial cells (HUVECs) were examined.

Methods: Angiogenesis-promoting effects (i.e., migration, invasion, DNA synthesis, and tube formation) in HUVECs of the conditioned media (CM) from various human CRC clones were analyzed. MMP activities were assessed using a zymography assay. Western blotting and selective inhibitors were used to dissect the signaling pathway involved. IHC was used to examine the vascular density in tumor xenografts.

Results: We found that the conditioned media (CM) collected from the GATA6-overexpressing clones enhanced angiogenesis of HUVECs more effectively which might be attributed partly to a higher MMP-9 production by HUVECs. Subsequently, elevated levels of IL-8 and VEGF-A were detected in the CM whose tube formation-enhancing activities were abolished by the co-treatment with either a VEGFR2 inhibitor or an IL-8 neutralizing antibody. Interestingly, increased production of these cytokines in the GATA6-overexpressing clones was due to an EGFR/AKT-mediated activation of NF-κB. Furthermore, not only were the levels of CD31 and endomucin but also the blood vessel density was much higher in the xenograft tumors grown from these clones.

Conclusion: Our findings demonstrate that human CRCSCs promote a stronger angiogenesis by producing higher amounts of angiogenic factors through activation of the EGFR/AKT/NF-κB pathway.

Keywords: EGFR; GATA6; NF-κB; angiogenesis; colorectal cancer stem cell.

MeSH terms

  • Cell Movement
  • Colorectal Neoplasms / metabolism*
  • Colorectal Neoplasms / pathology
  • Cytokines / metabolism*
  • ErbB Receptors / metabolism
  • GATA6 Transcription Factor / metabolism
  • HCT116 Cells
  • HT29 Cells
  • Human Umbilical Vein Endothelial Cells
  • Humans
  • NF-kappa B / metabolism
  • Neoplastic Stem Cells / metabolism*
  • Neoplastic Stem Cells / pathology
  • Neovascularization, Pathologic / metabolism*
  • Neovascularization, Pathologic / pathology
  • Proto-Oncogene Proteins c-akt / metabolism
  • Signal Transduction*

Substances

  • Cytokines
  • GATA6 Transcription Factor
  • GATA6 protein, human
  • NF-kappa B
  • EGFR protein, human
  • ErbB Receptors
  • Proto-Oncogene Proteins c-akt