AP-1 and TGFß cooperativity drives non-canonical Hedgehog signaling in resistant basal cell carcinoma

Nat Commun. 2020 Oct 8;11(1):5079. doi: 10.1038/s41467-020-18762-5.

Abstract

Tumor heterogeneity and lack of knowledge about resistant cell states remain a barrier to targeted cancer therapies. Basal cell carcinomas (BCCs) depend on Hedgehog (Hh)/Gli signaling, but can develop mechanisms of Smoothened (SMO) inhibitor resistance. We previously identified a nuclear myocardin-related transcription factor (nMRTF) resistance pathway that amplifies noncanonical Gli1 activity, but characteristics and drivers of the nMRTF cell state remain unknown. Here, we use single cell RNA-sequencing of patient tumors to identify three prognostic surface markers (LYPD3, TACSTD2, and LY6D) which correlate with nMRTF and resistance to SMO inhibitors. The nMRTF cell state resembles transit-amplifying cells of the hair follicle matrix, with AP-1 and TGFß cooperativity driving nMRTF activation. JNK/AP-1 signaling commissions chromatin accessibility and Smad3 DNA binding leading to a transcriptional program of RhoGEFs that facilitate nMRTF activity. Importantly, small molecule AP-1 inhibitors selectively target LYPD3+/TACSTD2+/LY6D+ nMRTF human BCCs ex vivo, opening an avenue for improving combinatorial therapies.

Publication types

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

MeSH terms

  • Animals
  • Carcinoma, Basal Cell / metabolism*
  • Cell Line, Tumor
  • Cell Nucleus / metabolism
  • Chromatin / metabolism
  • DNA, Neoplasm / metabolism
  • Drug Resistance, Neoplasm
  • Extracellular Matrix / metabolism
  • Gene Ontology
  • Guanine Nucleotide Exchange Factors / metabolism
  • Hair Follicle / metabolism
  • Hedgehog Proteins / metabolism*
  • Humans
  • Mice
  • Mice, Inbred C57BL
  • NIH 3T3 Cells
  • Neoplasm Proteins / metabolism
  • Protein Binding
  • Signal Transduction*
  • Skin Neoplasms / metabolism*
  • Smad3 Protein / metabolism
  • Trans-Activators / metabolism
  • Transcription Factor AP-1 / metabolism*
  • Transforming Growth Factor beta / metabolism*
  • Up-Regulation

Substances

  • Chromatin
  • DNA, Neoplasm
  • Guanine Nucleotide Exchange Factors
  • Hedgehog Proteins
  • MRTFA protein, human
  • Neoplasm Proteins
  • Smad3 Protein
  • Trans-Activators
  • Transcription Factor AP-1
  • Transforming Growth Factor beta