All subunits of the interleukin-2 receptor are expressed by canine cutaneous mast cell tumours

J Comp Pathol. 2013 Jul;149(1):19-29. doi: 10.1016/j.jcpa.2012.11.232. Epub 2012 Dec 28.


Cutaneous mast cell tumours (MCTs) are among the most important skin tumours in dogs. Apart from c-KIT mutations, which are present in <18% of MCTs, little is known of the mechanisms of MCT development and independent growth of tumour cells. Recently, the α-subunit (CD25) of the interleukin (IL)-2 receptor (IL-2R) has been found to be expressed by canine cutaneous MCTs and this expression is negatively correlated with tumour grade. We thus hypothesized that the other two subunits of the IL-2R and the ligand IL-2 are also expressed and that IL-2-dependent pathways may have an impact on MCT development and independent tumour cell growth. Messenger RNA and protein expression levels of the IL-2R β-subunit (CD122), the IL-2R γ-subunit (CD132) and IL-2 were analyzed in canine cutaneous MCTs and compared with tumour grade and c-KIT mutation status. Eighty-six percent of the tumours expressed both subunits of the IL-2R and 64% expressed IL-2. In addition, neoplastic mast cells seem able to bind IL-2. IL-2Rγ and IL-2 protein expression levels were significantly decreased in higher grade tumours and IL-2 expression was significantly decreased in c-KIT mutated tumours. Thus, expression of the complete IL-2R and its ligand by canine cutaneous MCTs indicates a potential impact of IL-2R signalling in MCT development and tumour cell proliferation. The decrease in IL-2R expression with increasing histological evidence of malignancy suggests that the IL-2R may be more relevant for early MCT development and well-differentiated tumours.

MeSH terms

  • Animals
  • Biomarkers, Tumor / analysis
  • Dog Diseases / metabolism*
  • Dogs
  • Immunohistochemistry
  • Interleukin-2 / metabolism
  • Mastocytosis, Cutaneous / genetics
  • Mastocytosis, Cutaneous / metabolism
  • Mastocytosis, Cutaneous / veterinary*
  • Neoplasm Grading
  • Protein Subunits / metabolism
  • Proto-Oncogene Proteins c-kit / genetics
  • Real-Time Polymerase Chain Reaction
  • Receptors, Interleukin-2 / analysis
  • Receptors, Interleukin-2 / biosynthesis*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Skin Neoplasms / genetics
  • Skin Neoplasms / metabolism
  • Skin Neoplasms / veterinary*


  • Biomarkers, Tumor
  • Interleukin-2
  • Protein Subunits
  • Receptors, Interleukin-2
  • Proto-Oncogene Proteins c-kit