The syntenic lncRNA DANCR is a human melanoma oncogene and an essential regulator of zebrafish development
Long non-coding RNAs (lncRNAs) play crucial roles in regulating gene expression. Some are essential for organismal development and physiology, and they can contribute to diseases such as cancer. Whilst most lncRNAs exhibit little sequence similarity, conservation of lncRNA transcription relative to neighbouring protein-coding genes suggests potential functional significance. Nevertheless, most positionally equivalent lncRNAs are uncharacterized and it remains unclear whether they exert similar roles in distant species. Here, we identified syntenic melanoma-associated lncRNAs predicted to be components of the MITF gene regulatory network in human melanoma, with positionally equivalent transcripts in zebrafish. Among these, we prioritized Differentiation Antagonizing Non-Protein Coding RNA (DANCR), a cancer-associated lncRNA critical for maintaining somatic progenitor cells in human models, for functional investigation. Dancr is a multi-exonic, cytoplasmically enriched lncRNA transcribed from syntenic regions in the human and zebrafish genomes. MITF and c-MYC, key melanoma transcription factors, regulate human DANCR expression and melanoma patients with high DANCR display significantly decreased survival. DANCR is a melanoma oncogene that controls cancer-associated gene expression networks and promotes human melanoma cell proliferation and migration. Zebrafish dancr is dynamically expressed across multiple different cell types in the developing embryo, regulates genes involved in cell death, and is essential for embryonic development. Our work suggests that cancer-critical lncRNAs such as Dancr, expressed from similar regions in vertebrate genomes, may regulate related genes and processes involved in both embryonic development and tumorigenesis across species. Overall design: RNA-sequencing of DANCR loss-of-function human melanoma cells and whole zebrafish embryos and controls