Skin (SKIN)

Overview

SKIN is the OncoTree tissue-level node representing cutaneous/skin tissue, classified under Skin Cancer in OncoTree (parent: TISSUE). In the cbio-kb corpus this code is used to represent normal cutaneous skin in the context of somatic mutation and melanocyte biology studies, distinct from the melanoma (MEL) and cutaneous squamous cell carcinoma (CSCC) entity pages.

Cohorts in the corpus

  • Normal skin melanocyte atlas: 297 single melanocytes from 58 skin biopsies of 31 donors (UCSF Willed Body Program and Northwestern University dermatology clinic). Donors spanned ages and sun-exposure histories; one FFPE Xenium specimen was non-lesional adjacent skin from a MEL patient (63-year-old male). Dataset: normal_skin_melanocytes_2024 (dbGaP phs001979.v1.p1 and phs003683.v2.p1). PMID:39975212

Recurrent alterations

This is primarily a normal-tissue atlas study; no somatic drivers are nominated in skin. Somatic mutations profiled are from normal sun-exposed melanocytes.

  • UV-attributable signature SBS7 (C>T transitions at dipyrimidines): dominant in HighMut melanocytes from sun-damaged skin. PMID:39975212
  • Clock-like signatures SBS1/SBS5: dominant in LowMut melanocytes, enriched in hair-follicle niches. PMID:39975212
  • NanoSeq profiling of paired pre/post NB-UVB skin biopsies (16 psoriasis patients) quantified UVR-induced SBS7a/SBS7b mutation burden increase (median 0.55 substitutions/Mb in buttock, 0.89/Mb in forearm); surveillance-modelling recommends skin-cancer monitoring starting at 58–422 NB-UVB exposures (vs BAD guideline of 500) depending on sun-exposure behaviour and MED PMID:26950094

Subtypes

Two coexisting melanocyte subpopulations identified within sun-damaged skin: - HighMut melanocytes: UV-signature dominant (SBS7), dendritic morphology, large, transcriptionally “differentiated”; reside in interfollicular epidermis; upregulate HMOX1, ABCC2, MC1R, HERC2. PMID:39975212 - LowMut melanocytes: clock-like signature dominant (SBS1/SBS5), smaller, less dendritic, “stem-like” / neural-crest-lineage; enriched in hair follicles; upregulate VCAN, TAGLN, SEMA3C, TCF4. PMID:39975212

Therapeutic landscape

  • No therapeutic interventions reported in this corpus entry. Authors hypothesize that the hair-follicle LowMut melanocyte reservoir could be co-opted to replace UV-damaged cells, paralleling vitiligo phototherapy models, but no validated intervention is described. PMID:39975212

Sources

  • PMID:39975212 — Tandukar et al. Nature 2025. Clonal single-cell profiling of normal skin melanocytes reveals UV-protected stem-cell niche in hair follicles.

  • PMID:26950094 — Fowler et al., NanoSeq NB-UVB phototherapy study; SBS7a/SBS7b mutation burden in normal skin as precursor to cSCC/BCC; skin-cancer surveillance modelling

This page was processed by entity-page-writer on 2026-05-15.