Functional imaging of proteolysis: stromal and inflammatory cells increase tumor proteolysis

Mol Imaging. 2003 Jul;2(3):159-75. doi: 10.1162/153535003322556903.

Abstract

The underlying basement membrane is degraded during progression of breast and colon carcinoma. Thus, we imaged degradation of a quenched fluorescent derivative of basement membrane type IV collagen (DQ-collagen IV) by living human breast and colon tumor spheroids. Proteolysis of DQ-collagen IV by HCT 116 and HKh-2 human colon tumor spheroids was both intracellular and pericellular. In contrast, proteolysis of DQ-collagen IV by BT20 human breast tumor spheroids was pericellular. As stromal elements can contribute to proteolytic activities associated with tumors, we also examined degradation of DQ-collagen IV by human monocytes/macrophages and colon and breast fibroblasts. Fibroblasts themselves exhibited a modest amount of pericellular degradation. Degradation was increased 4-17-fold in cocultures of fibroblasts and tumor cells as compared to either cell type alone. Inhibitors of matrix metalloproteinases, plasmin, and the cysteine protease, cathepsin B, all reduced degradation in the cocultures. Monocytes did not degrade DQ-collagen IV; however, macrophages degraded DQ-collagen IV intracellularly. In coculture of tumor cells, fibroblasts, and macrophages, degradation of DQ-collagen IV was further increased. Imaging of living tumor and stromal cells has, thus, allowed us to establish that tumor proteolysis occurs pericellularly and intracellularly and that tumor, stromal, and inflammatory cells all contribute to degradative processes.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Breast Neoplasms / pathology
  • Carcinoma / pathology
  • Cell Differentiation / drug effects
  • Cell Line, Tumor
  • Cell Movement
  • Cell Survival
  • Coculture Techniques
  • Collagen / metabolism
  • Collagen Type IV / metabolism
  • Colonic Neoplasms / pathology
  • Drug Combinations
  • Endopeptidases / drug effects
  • Endopeptidases / metabolism*
  • Humans
  • Hydroxamic Acids / pharmacology
  • Image Processing, Computer-Assisted*
  • Immunohistochemistry
  • Laminin / metabolism
  • Macrophages / cytology
  • Macrophages / metabolism*
  • Monocytes / drug effects
  • Neoplasms / enzymology
  • Neoplasms / metabolism*
  • Neoplasms / pathology
  • Proteoglycans / metabolism
  • Spheroids, Cellular / enzymology
  • Spheroids, Cellular / metabolism*
  • Stromal Cells / cytology
  • Stromal Cells / enzymology*
  • Stromal Cells / immunology
  • Tetradecanoylphorbol Acetate / pharmacology
  • U937 Cells

Substances

  • BB 3103
  • Collagen Type IV
  • Drug Combinations
  • Hydroxamic Acids
  • Laminin
  • Proteoglycans
  • matrigel
  • Collagen
  • Endopeptidases
  • Tetradecanoylphorbol Acetate