Melanoma
HPV8 Field Cancerization in a Transgenic Mouse Model Is due to Lrig1+ Keratinocyte Stem Cell Expansion
β-Human papillomaviruses (HPVs) cause near ubiquitous latent skin infection within long-lived hair follicle (HF) keratinocyte stem cells. In patients with epidermodysplasia verruciformis, β-HPV viral replication is associated with skin keratosis and cutaneous squamous cell carcinoma. To determine the role of HF keratinocyte stem cells in β-HPV-induced skin carcinogenesis, we utilized a transgenic mouse model in which the keratin 14 promoter drives expression of the entire HPV8 early region (HPV8tg).CXCR3 Depleting Antibodies Prevent and Reverse Vitiligo in Mice
Vitiligo is a disfiguring skin disease in which melanocytes with intrinsic abnormalities are targeted and destroyed by autoreactive CD8+ T cells in the epidermis, resulting in patchy depigmentation (Palermo et al., 2001; van den Boorn et al., 2009, and reviewed in Richmond et al., 2013). Although it is one of the most common autoimmune diseases, affecting 1% of the population worldwide, there are no Food and Drug Administration-approved treatments. Previous work from our lab has shown that CD8+ T-cell recruitment to the skin in a mouse model of vitiligo is dependent on IFNγ (Harris et al., 2012) and the downstream CXCR3 chemokine system (Rashighi et al., 2014).RASopathy Gene Mutations in Melanoma
Next-generation sequencing of melanomas has unraveled critical driver genes and genomic abnormalities, mostly defined as occurring at high frequency. In addition, less abundant mutations are present that link melanoma to a set of disorders, commonly called RASopathies. These disorders, which include neurofibromatosis and Noonan and Legius syndromes, harbor germline mutations in various RAS/mitogen-activated protein kinase signaling pathway genes. We highlight shared amino acid substitutions between this set of RASopathy mutations and those observed in large-scale melanoma sequencing data, uncovering a significant overlap.Mosaic Activating Mutations in GNA11 and GNAQ Are Associated with Phakomatosis Pigmentovascularis and Extensive Dermal Melanocytosis
Common birthmarks can be an indicator of underlying genetic disease but are often overlooked. Mongolian blue spots (dermal melanocytosis) are usually localized and transient, but they can be extensive, permanent, and associated with extracutaneous abnormalities. Co-occurrence with vascular birthmarks defines a subtype of phakomatosis pigmentovascularis, a group of syndromes associated with neurovascular, ophthalmological, overgrowth, and malignant complications. Here, we discover that extensive dermal melanocytosis and phakomatosis pigmentovascularis are associated with activating mutations in GNA11 and GNAQ, genes that encode Gα subunits of heterotrimeric G proteins.
