Increased PHGDH Expression Uncouples Hair Follicle Cycle Progression and Promotes Inappropriate Melanin Accumulation

The study investigated the effects of increased PHGDH expression, a gene involved in serine biosynthesis, using a mouse model with inducible PHGDH expression. The results showed that increased PHGDH expression led to inappropriate melanin accumulation in early-stage hair follicles (anagen II) without altering the overall hair follicle cycle timing. This was accompanied by an increase in melanocyte abundance. These findings suggested that PHGDH expression might influence melanocyte proliferation or differentiation, providing insights into its role in normal melanocyte biology and its frequent copy number gain in melanoma compared to other cancers.