Unwelcome complement

Cancer Res. 2009 Aug 15;69(16):6367-70. doi: 10.1158/0008-5472.CAN-09-1918. Epub 2009 Aug 4.


For decades, the complement system has been recognized as an effector arm of the innate immunity system that contributes to the destruction of tumor cells. However, recent studies have challenged this paradigm by demonstrating that a complement component, the anaphylatoxin C5a, promotes the growth of malignant tumors in a mouse model of cervical carcinoma. The effect of C5a on tumor growth was associated with the recruitment of myeloid-derived suppressor cells to tumors, followed by the activation of these cells. These unexpected findings identify the complement system as a potential new target for anticancer immunotherapy.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • Complement System Proteins / immunology
  • Complement System Proteins / physiology*
  • Humans
  • Immunotherapy / methods
  • Immunotherapy / trends
  • Mice
  • Models, Biological
  • Myeloid Cells / immunology
  • Myeloid Cells / physiology
  • Neoplasms / etiology*
  • Neoplasms / immunology*
  • Neoplasms / therapy
  • Tumor Escape / immunology


  • Complement System Proteins