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Published on: October 27, 2020

Down-regulation of TGF-beta receptors in human colorectal cancer: implications for cancer development

M Matsushita1, K Matsuzaki, M Date

  • 1Third Department of Internal Medicine, Kansai Medical University, Moriguchi, Osaka, Japan.

British Journal of Cancer
|July 2, 1999
PubMed

Insights

Colorectal cancer cells evade growth inhibition by down-regulating transforming growth factor-beta (TGF-beta) receptors. This study reveals TGF-beta

Area of Science:

  • Molecular Biology
  • Oncology
  • Gastroenterology

Background:

  • Colorectal cancer (CRC) cells often exhibit resistance to the anti-proliferative signals of transforming growth factor-beta (TGF-beta).
  • TGF-beta functions as a paracrine factor, influencing mesenchymal cells surrounding cancer cells.

Purpose of the Study:

  • To investigate the expression patterns of TGF-beta and its receptors in human colorectal cancer tissues.
  • To ascertain the correlation between TGF-beta signaling components and colorectal cancer progression.

Main Methods:

  • Utilized in situ hybridization and Northern blot hybridization to detect TGF-beta1, type I, and type II receptor mRNA.
  • Employed immunohistochemical staining for TGF-beta1 protein.
  • Analyzed human colorectal adenomas, cancers, and normal mucosas.

Main Results:

  • TGF-beta receptor mRNAs were predominantly expressed in normal colorectal epithelial cells and adenomas, but showed significantly reduced expression in most colorectal cancers.
  • Intense signals for TGF-beta1 mRNA and protein were observed in all colorectal cancers, also present in stromal fibroblasts and endothelial cells.
  • Smad 4 protein translocation to the nucleus upon TGF-beta stimulation occurred in adenoma cells but was absent in cancer cells.

Conclusions:

  • Human colon cancers escape TGF-beta-mediated growth inhibition through the downregulation of its receptors.
  • TGF-beta influences stroma formation and angiogenesis, suggesting a role in colorectal cancer progression within the host environment.

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