Single Molecule FISH for Hedgehog Signaling in Mouse Skin

The study by Adolphe et al. used single molecule fluorescent in situ hybridization (smFISH) to quantify Hedgehog (Hh) signaling levels in mouse skin, revealing a gradient of Hh pathway activation that may specify hair follicle development. They found that Ptch1 is the primary regulator of Hh signaling, with Ptch2 playing a secondary role. Loss of Ptch1 alone led to increased Hh signaling and hyperplastic growth, while combined loss of Ptch1 and Ptch2 resulted in more severe neoplasias. The study suggested that smFISH could be a useful diagnostic tool for differentiating between benign, drug-sensitive, and drug-resistant Hh-driven tumors.