miR-181a Promotes Multiple Protumorigenic Functions by Targeting TGFβR3

J Invest Dermatol. 2022 Jul;142(7):1956-1965.e2. doi: 10.1016/j.jid.2021.09.040. Epub 2021 Dec 8.


Cutaneous squamous cell carcinoma (cSCC) comprises 15‒20% of all skin cancers and has a well-defined progression sequence from precancerous actinic keratosis to invasive cSCC. To identify targets for chemoprevention, we previously reported a cross-species analysis to identify the transcriptional drivers of cSCC development and identified miR-181a as a potential oncomiR. We show that the upregulation of miR-181a promotes multiple protumorigenic properties by targeting an understudied component of TGFβ signaling, TGFβR3. miR-181a and TGFβR3 are upregulated and downregulated, respectively, in cSCC. miR-181a overexpression (OE) and TGFβR3 knockdown (KD) significantly suppresses UV-induced apoptosis in HaCaT cells and in primary normal human epidermal keratinocytes. In addition, OE of miR-181a or KD of TGFβR3 by short hairpin RNA enhances anchorage-independent survival. miR-181a OE or TGFβR3 KD enhances cellular migration and invasion and upregulation of epithelial‒mesenchymal transition markers. Luciferase reporter assays demonstrate that miR-181a directly targets the 3'-untranslated region of TGFβR3. miR-181a upregulates phosphorylated SMAD3 levels after TGFβ2 administration and results in elevated SNAIL and SLUG expression. Finally, we confirm in vivo that miR-181a inhibition compromises tumor growth. Importantly, these phenotypes can be reversed with TGFβR3 OE or KD in the context of miR-181a OE or KD, respectively, further highlighting the physiologic relevance of this regulation in cSCC.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3' Untranslated Regions / genetics
  • Carcinoma, Squamous Cell* / pathology
  • Cell Line, Tumor
  • Cell Proliferation / genetics
  • Gene Expression Regulation, Neoplastic
  • Humans
  • MicroRNAs* / genetics
  • Proteoglycans* / genetics
  • Receptors, Transforming Growth Factor beta* / genetics
  • Skin Neoplasms* / pathology


  • 3' Untranslated Regions
  • MIrn181 microRNA, human
  • MicroRNAs
  • Proteoglycans
  • Receptors, Transforming Growth Factor beta
  • betaglycan