PTENP1-AS contributes to BRAF inhibitor resistance and is associated with adverse clinical outcome in stage III melanoma

Sci Rep. 2021 May 26;11(1):11023. doi: 10.1038/s41598-021-89389-9.

Abstract

BRAF inhibitors (BRAFi) selectively target oncogenic BRAFV600E/K and are effective in 80% of advanced cutaneous malignant melanoma cases carrying the V600 mutation. However, the development of drug resistance limits their clinical efficacy. Better characterization of the underlying molecular processes is needed to further improve treatments. We previously demonstrated that transcription of PTEN is negatively regulated by the PTEN pseudogene antisense RNA, PTENP1-AS, and here we investigated the impact of this transcript on clinical outcome and BRAFi resistance in melanoma. We observed that increased expression levels of PTENP1-AS in BRAFi resistant cells associated with enrichment of EZH2 and H3K27me3 at the PTEN promoter, consequently reducing the expression levels of PTEN. Further, we showed that targeting of the PTENP1-AS transcript sensitized resistant cells to BRAFi treatment and that high expression of PTENP1-AS in stage III melanoma correlated with poor survival. Collectively, the data presented here show that PTENP1-AS is a promising target for re-sensitizing cells to BRAFi and also a possible prognostic marker for clinical outcome in stage III melanoma.

MeSH terms

  • Cell Line, Tumor
  • Drug Resistance, Neoplasm* / genetics
  • Enhancer of Zeste Homolog 2 Protein / antagonists & inhibitors
  • Enhancer of Zeste Homolog 2 Protein / genetics
  • Enhancer of Zeste Homolog 2 Protein / metabolism
  • Female
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Male
  • Melanoma* / drug therapy
  • Melanoma* / genetics
  • Melanoma* / metabolism
  • Melanoma* / mortality
  • Melanoma* / pathology
  • Neoplasm Staging
  • PTEN Phosphohydrolase* / genetics
  • PTEN Phosphohydrolase* / metabolism
  • Prognosis
  • Promoter Regions, Genetic
  • Protein Kinase Inhibitors / pharmacology
  • Protein Kinase Inhibitors / therapeutic use
  • Proto-Oncogene Proteins B-raf* / antagonists & inhibitors
  • Proto-Oncogene Proteins B-raf* / genetics
  • RNA, Antisense / genetics
  • Skin Neoplasms / drug therapy
  • Skin Neoplasms / genetics
  • Skin Neoplasms / mortality
  • Skin Neoplasms / pathology

Substances

  • Proto-Oncogene Proteins B-raf
  • PTEN Phosphohydrolase
  • PTEN protein, human
  • BRAF protein, human
  • Protein Kinase Inhibitors
  • RNA, Antisense
  • Enhancer of Zeste Homolog 2 Protein