miR-375 inhibits IFN-γ-induced programmed death 1 ligand 1 surface expression in head and neck squamous cell carcinoma cells by blocking JAK2/STAT1 signaling

Oncol Rep. 2018 Mar;39(3):1461-1468. doi: 10.3892/or.2018.6177. Epub 2018 Jan 2.

Abstract

Upregulation of programmed death 1 ligand 1 (PD-L1) in cancer cells and its ligation to PD-1 on T cells facilitates cancer cell escape from immune surveillance. Therapies with PD-1 or PD-L1 antibodies have resulted in marked clinical responses in various cancer types. Hence, modulators that inhibit PD-L1 expression in cancer cells may serve as a novel strategy by which to enhance host immune responses. In the present study, we investigated the effects of miR-375 on PD-L1 expression in head and neck squamous cell carcinoma (HNSCC) cells by qRT-PCR and western blot analyses. We confirmed that miR-375 inhibited IFN-γ-induced PD-L1 surface expression in HNSCC cells, and we observed that Janus kinase 2 (JAK2) is a bona fide target of miR-375 and further activated signal transducer and activator of transcription 1 (STAT1). Additionally, miR-375-mediated inhibition of PD-L1 expression was dependent on the JAK2/STAT1 pathway. Therefore, by attenuating PD-1/PD-L1 signaling, miR-375 may also serve as a modulator to increase the cell immune responses to HNSCC.

MeSH terms

  • Apoptosis
  • B7-H1 Antigen / genetics
  • B7-H1 Antigen / metabolism*
  • Biomarkers, Tumor / genetics
  • Biomarkers, Tumor / metabolism*
  • Carcinoma, Squamous Cell / genetics
  • Carcinoma, Squamous Cell / metabolism
  • Carcinoma, Squamous Cell / pathology*
  • Cell Proliferation
  • Head and Neck Neoplasms / drug therapy
  • Head and Neck Neoplasms / genetics
  • Head and Neck Neoplasms / metabolism
  • Head and Neck Neoplasms / pathology*
  • Humans
  • Interferon-gamma / pharmacology
  • Janus Kinase 2 / genetics
  • Janus Kinase 2 / metabolism*
  • MicroRNAs / genetics*
  • STAT1 Transcription Factor / genetics
  • STAT1 Transcription Factor / metabolism*
  • Signal Transduction
  • Tumor Cells, Cultured

Substances

  • B7-H1 Antigen
  • Biomarkers, Tumor
  • CD274 protein, human
  • MIRN375 microRNA, human
  • MicroRNAs
  • STAT1 Transcription Factor
  • STAT1 protein, human
  • Interferon-gamma
  • JAK2 protein, human
  • Janus Kinase 2