STAT3, STAT5A, STAT5B and STAT6 proteins are overexpressed in human basal cell carcinoma

Clin Exp Dermatol. 2020 Mar;45(2):165-171. doi: 10.1111/ced.14048. Epub 2019 Aug 27.


Background: The molecular pathogenesis of basal cell carcinoma (BCC) is still not precisely described and is the subject of ongoing studies. The role of signal transducers and activators of transcription (STATs) in human epithelial carcinogenesis has been poorly investigated, but in the era of studies on inhibitors targeting STAT proteins this topic seems worth exploring. Increased expression of STAT3 in human nonmelanoma skin cancer (NMSC) has been confirmed in a few studies, but to our knowledge, expression of STAT5A, STAT5B and STAT6 in BCC has not been previously evaluated.

Aim: To measure expression of STAT3, STAT5A, STAT5B and STAT6 expression in different histopathological subtypes of human BCC and its correlation with selected clinical variables.

Methods: Immunohistochemistry was used to assess 60 BCC tumour specimens [20 superficial (s)BCCs, 20 nodular (n)BCCs and 20 infiltrative (i)BCCs] and to compare with specimens of healthy skin. There was no significant difference in age or sex between the three groups of patients with BCC. As many tumours showed heterogeneity of staining, the H-score system was applied to calculate the intensity of immunoexpression.

Results: Expression of STAT3, STAT5A, STAT5B and STAT6 was observed in all histopathological subtypes of BCC, and was stronger than the expression within the adjacent epidermis and also stronger than the expression within the epidermis in the healthy control group. Statistical analysis revealed no significant differences in mean H-scores calculated for sBCCs, nBCCs and iBCCs. There were no statistically significant associations between STAT3, STAT5A, STAT5B and STAT6 expression and patient sex/age, and tumour size/site.

Conclusion: Our results confirm a possible role of STATs in the pathogenesis of BCC and should encourage future investigations on the possible therapeutic implications of this finding.

MeSH terms

  • Carcinoma, Basal Cell / metabolism*
  • Humans
  • Immunohistochemistry
  • STAT Transcription Factors / metabolism*
  • STAT3 Transcription Factor / metabolism
  • STAT5 Transcription Factor / metabolism
  • STAT6 Transcription Factor / metabolism
  • Signal Transduction / physiology
  • Skin Neoplasms / metabolism*
  • Statistics, Nonparametric
  • Tumor Suppressor Proteins / metabolism


  • STAT Transcription Factors
  • STAT3 Transcription Factor
  • STAT3 protein, human
  • STAT5 Transcription Factor
  • STAT5A protein, human
  • STAT5B protein, human
  • STAT6 Transcription Factor
  • STAT6 protein, human
  • Tumor Suppressor Proteins