MITF-low melanoma subtype models in zebrafish reveal transcriptional sub-clusters and MITF-independent residual disease
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA564013 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR10070600_1.fastq.gz | Fastqsanger.gz | |||
| SRR10070600_2.fastq.gz | Fastqsanger.gz | |||
| SRR10070700_1.fastq.gz | Fastqsanger.gz | |||
| SRR10070700_2.fastq.gz | Fastqsanger.gz | |||
| SRR10070800_1.fastq.gz | Fastqsanger.gz |
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Project description:The MITF-low melanoma transcriptional signature is predictive of poor outcome for patients but little is known about its biological signature. We used genetic models of zebrafish with low expression of mitfa (MITF-low) to study this biological subtype. Using genetic inhibition of MITF activity we discover minimal residual disease at the site of regression. We performed single cell RNA-seq (Smart-seq2) to characterise cells at the site of residual disease, and put in relation with primary tumours and recurring disease.
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Project description:The MITF-low melanoma transcriptional signature is predictive of poor outcome for patients but little is known about its biological signature. We used genetic models of zebrafish with low expression of mitfa (MITF-low) to study this biological subtype. We performed whole bulk RNA-seq to classify zebrafish MITF-low melanoma that cluster mainly by their directionality of growth and assess their resemblance to patients’ MITF-low subgroups. Furthermore, using genetic inhibition of MITF activity we discover minimal residual disease at the site of regression and using single-cell and low input RNA-seq we characterise these MITF independent cells and show that they pre-exist in the primary tumour.
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Project description:MITF-low zebrafish melanomas reveal cells with no MITF activity at the site of residual disease
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Project description:The melanocyte-inducing transcription factor (MITF)-low melanoma transcriptional signature is predictive of poor outcomes for patients, but little is known about its biological significance, and animal models are lacking. Here, we used zebrafish genetic models with low activity of Mitfa (MITF-low) and established that the MITF-low state is causal of melanoma progression and a predictor of melanoma biological subtype. MITF-low zebrafish melanomas resembled human MITF-low melanomas and were enriched for stem and invasive (mesenchymal) gene signatures. MITF-low activity coupled with a p53 mutation was sufficient to promote superficial growth melanomas, whereas BRAFV600E accelerated MITF-low melanoma onset and further promoted the development of MITF-high nodular growth melanomas. Genetic inhibition of MITF activity led to rapid regression; recurrence occurred following reactivation of MITF. At the regression site, there was minimal residual disease that was resistant to loss of MITF activity (termed MITF-independent cells) with very low-to-no MITF activity or protein. Transcriptomic analysis of MITF-independent residual disease showed enrichment of mesenchymal and neural crest stem cell signatures similar to human therapy-resistant melanomas. Single-cell RNA sequencing revealed MITF-independent residual disease was heterogeneous depending on melanoma subtype. Further, there was a shared subpopulation of residual disease cells that was enriched for a neural crest G0-like state that preexisted in the primary tumor and remained present in recurring melanomas. These findings suggest that invasive and stem-like programs coupled with cellular heterogeneity contribute to poor outcomes for MITF-low melanoma patients and that MITF-independent subpopulations are an important therapeutic target to achieve long-term survival outcomes. SIGNIFICANCE: This study provides a useful model for MITF-low melanomas and MITF-independent cell populations that can be used to study the mechanisms that drive these tumors as well as identify potential therapeutic options.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/22/5769/F1.large.jpg.
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