ISL1

Overview

ISL1 (ISL LIM homeobox 1) is a LIM-homeodomain transcription factor required for the development of the sympathetic nervous system and adrenal medulla. In neuroblastoma, ISL1 serves as a marker of the noradrenergic differentiation program that characterizes low-risk tumors.

Alterations observed in the corpus

• ISL1 is part of the noradrenergic/adrenergic panel (PHOX2B, PHOX2A, TH, DBH, CHGA, CHGB, PNMT, ISL1) marking NOR tumor clusters (nC5/nC7/nC8/nC9) and postnatal chromaffin cells in neuroblastoma snRNA-seq analysis PMID:34493726.
• NOR clusters over-express ISL1 (FDR <0.01, Welch’s t-test) compared to the undifferentiated high-risk nC3 cluster and the postnatal human progenitor hC1, both of which lack the noradrenergic gene program PMID:34493726.

Cancer types (linked)

• NBL — ISL1 marks the noradrenergic lineage of low-risk neuroblastoma; its absence in the undifferentiated nC3 cluster is a feature of high-risk tumor identity PMID:34493726.

Co-occurrence and mutual exclusivity

• Co-expressed with TH, DBH, PHOX2A, PHOX2B, CHGA in noradrenergic NOR clusters; mutually exclusive with NTRK2-high undifferentiated nC3 cells PMID:34493726.

Therapeutic relevance

• ISL1 expression level reflects the degree of noradrenergic differentiation in neuroblastoma; higher ISL1 correlates with low-risk, favorable-outcome tumor identity PMID:34493726.

Open questions

• The transcriptional mechanisms by which ISL1 is silenced in high-risk neuroblastoma progenitor-like cells are not addressed in the corpus PMID:34493726.

Sources

• PMID:34493726

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