[Role of proteins of the macroglobulin family in regulation of tumor growth]

Ontogenez. Jan-Feb 2006;37(1):12-9.
[Article in Russian]

Abstract

Proteins of the macroglobulin family are an ancient and evolutionarily conservative link of the immune system, which is actively involved in both inhibition of tumor growth cells and proliferation of tumor cells. Two basically different binding sites and a great conformational plasticity of all representatives of the macroglobulin family, as well as the presence of two to four representatives of the family in the blood of most species allow them to transport diverse substances and exert various regulatory influences on both the tumor and the entire organism. For example, the capacity of macroglobulins for binding hydrolases makes it possible to inhibit enzyme mediated tumor invasion. At the same time, an excess of macroglobulin/hydrolase complexes can activate apoptosis. The tumor is able of using macroglobulins, especially pregnancy-associated proteins, for its own protection. Specifically, pregnancy-associated alpha2-glycoprotein, which is actively produced by human tumor cells, blocks the histocompatibility complex antigens. On the contrary, the capacity of binding zinc stimulates the thymulin-dependent activation of natural killer cells. Nevertheless, the actively growing tumor expresses many receptors to macroglobulins, which are the main carriers of some cytokines and growth factors essential for proliferation.

Publication types

  • English Abstract
  • Review

MeSH terms

  • Animals
  • Apoptosis / immunology
  • Biological Transport / immunology
  • Cell Proliferation*
  • Evolution, Molecular
  • Female
  • Histocompatibility Antigens / immunology
  • Histocompatibility Antigens / metabolism
  • Humans
  • Hydrolases / immunology
  • Hydrolases / metabolism*
  • Killer Cells, Natural / immunology
  • Killer Cells, Natural / metabolism
  • Multiprotein Complexes / immunology
  • Multiprotein Complexes / metabolism*
  • Neoplasm Metastasis
  • Neoplasms / immunology
  • Neoplasms / metabolism*
  • Pregnancy
  • Pregnancy-Associated alpha 2-Macroglobulins / immunology
  • Pregnancy-Associated alpha 2-Macroglobulins / metabolism*
  • Thymic Factor, Circulating / immunology
  • Thymic Factor, Circulating / metabolism
  • Tumor Escape*

Substances

  • Histocompatibility Antigens
  • Multiprotein Complexes
  • Pregnancy-Associated alpha 2-Macroglobulins
  • Thymic Factor, Circulating
  • Hydrolases