Interleukin-6 stimulates clonogenic growth of primary and metastatic human colon carcinoma cells

Cancer Lett. 2000 Apr 3;151(1):31-8. doi: 10.1016/s0304-3835(99)00401-2.


Interleukin-6 (IL-6) is a pleiotropic cytokine which exerts biological activities on various cell types including neoplastic cells. We have investigated the biological effect of IL-6 and the expression of IL-6 receptors (IL-6R) on human colorectal carcinoma cell lines. Isreco-1 was derived from the primary site of a colon cancer while Isreco-2 and Isreco-3 were established from a liver and peritoneal metastasis of the same patient. IL-6 stimulated colony formation in methylcellulose of Isreco-1 cells to 150% (P < 0.05). The effect was even more pronounced on the metastatic Isreco-2 line where colony numbers in the presence of IL-6 were enhanced up to four-fold (P < 0.0001) in a dose-dependent fashion. An anti-IL-6 antibody completely abolished this growth stimulatory effect of IL-6. RT-PCR analysis revealed transcripts for IL-6Ralpha and gp 130 in these cell lines. Experiments with additional cell lines confirmed the general expression of gp130 but showed limited expression of the IL-6Ralpha chain. Surprisingly, about half of the cell lines tested expressed IL-6 mRNA at low levels which was not translated into protein. Our results suggest that IL-6 can potently stimulate anchorage-independent growth of some colorectal carcinoma cells. This stimulation appears to occur through a paracrine mechanism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Division / drug effects
  • Colonic Neoplasms / immunology
  • Colonic Neoplasms / pathology*
  • Colorectal Neoplasms / immunology
  • Colorectal Neoplasms / pathology
  • Humans
  • Interleukin-6 / pharmacology*
  • Liver Neoplasms / immunology
  • Liver Neoplasms / pathology
  • Liver Neoplasms / secondary
  • Neoplasm Metastasis
  • Peritoneal Neoplasms / immunology
  • Peritoneal Neoplasms / pathology
  • Peritoneal Neoplasms / secondary
  • Receptors, Interleukin-6 / genetics
  • Receptors, Interleukin-6 / physiology*
  • Recombinant Proteins / pharmacology
  • Reverse Transcriptase Polymerase Chain Reaction
  • Tumor Cells, Cultured


  • Interleukin-6
  • Receptors, Interleukin-6
  • Recombinant Proteins