Interleukin-6-induced epithelial-mesenchymal transition through signal transducer and activator of transcription 3 in human cervical carcinoma

Int J Oncol. 2014 Jul;45(1):165-76. doi: 10.3892/ijo.2014.2422. Epub 2014 May 6.

Abstract

Epithelial-mesenchymal transition (EMT) is an important process in the invasion and metastasis of human cervical carcinoma. The pro-inflammatory cytokine interleukin-6 (IL-6) has been shown as an EMT inducer in multiple carcinomas. However, whether the EMT program can be induced by IL-6 and the mechanisms underlying the IL-6-induced EMT in human cervical carcinoma remain to be determined. In this study, we show that IL-6 receptor (IL-6R) and signal transducer and activator of transcription 3 (Stat3) were highly expressed in human cervical squamous cell carcinoma (CSCC) tissues, and the expression of EMT markers was reversed in well-differentiated and poorly-differentiated human CSCC. Additional experiments showed that IL-6 exposure in cervical carcinoma cell lines induced IL-6R and Stat3 expression, markedly promoted cell growth, and altered cell morphology. The treatment of cervical carcinoma cell lines with IL-6 resulted in downregulation of E-Cadherin and upregulation of Vimentin. Importantly, knockdown of Stat3 significantly reversed the IL-6-induced EMT program, suggesting that Stat3 is necessary for IL-6-induced EMT in the progression of human cervical carcinoma. Moreover, Slug, a member of the Snail family of EMT regulators, was observed to be associated with the expression of Stat3. We concluded that IL-6 plays an important role through Stat3 in the EMT induction and can be a potential therapeutic target and biomarker for human cervical carcinoma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / pharmacology
  • Biomarkers, Tumor / metabolism
  • Cadherins / metabolism
  • Carcinoma, Squamous Cell / metabolism
  • Carcinoma, Squamous Cell / pathology*
  • Cell Differentiation / drug effects
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Curcumin / pharmacology
  • Epithelial-Mesenchymal Transition / drug effects*
  • Female
  • Gene Expression Regulation, Neoplastic / drug effects
  • HeLa Cells
  • Humans
  • Interleukin-6 / metabolism*
  • Interleukin-6 / pharmacology
  • Phosphorylation
  • Receptors, Interleukin-6 / metabolism*
  • STAT3 Transcription Factor / genetics
  • STAT3 Transcription Factor / metabolism*
  • Uterine Cervical Neoplasms / metabolism
  • Uterine Cervical Neoplasms / pathology*
  • Vimentin / metabolism

Substances

  • Antineoplastic Agents
  • Biomarkers, Tumor
  • Cadherins
  • Interleukin-6
  • Receptors, Interleukin-6
  • STAT3 Transcription Factor
  • STAT3 protein, human
  • Vimentin
  • Curcumin