Julio C. Salas-Alanis

Fibroblast-Derived Dermal Matrix Drives Development of Aggressive Cutaneous Squamous Cell Carcinoma in Patients with Recessive Dystrophic Epidermolysis Bullosa

Patients with the genetic skin blistering disease recessive dystrophic epidermolysis bullosa (RDEB) develop aggressive cutaneous squamous cell carcinoma (cSCC). Metastasis leading to mortality is greater in RDEB than in other patient groups with cSCC. Here we investigate the dermal component in RDEB using mRNA expression profiling to compare cultured fibroblasts isolated from individuals without cSCC and directly from tumor matrix in RDEB and non-RDEB samples. Although gene expression of RDEB normal skin fibroblasts resembled that of cancer-associated fibroblasts, RDEB cancer-associated fibroblasts exhibited a distinct and divergent gene expression profile, with a large proportion of the differentially expressed genes involved in matrix and cell adhesion. RDEB cancer-associated fibroblasts conferred increased adhesion and invasion to tumor and nontumor keratinocytes. Reduction of COL7A1, the defective gene in RDEB, in normal dermal fibroblasts led to increased type XII collagen, thrombospondin-1, and Wnt-5A, while reexpression of wild type COL7A1 in RDEB fibroblasts decreased type XII collagen, thrombospondin-1, and Wnt-5A expression, reduced tumor cell invasion in organotypic culture, and restricted tumor growth in vivo. Overall, our findings show that matrix composition in patients with RDEB is a permissive environment for tumor development, and type VII collagen directly regulates the composition of matrix proteins secreted by dermal and cancer-associated fibroblasts.

Innate sensing of microbial products promotes wound-induced skin cancer

The association between tissue damage, chronic inflammation and cancer is well known. However, the underlying mechanisms are unclear. Here we characterize a mouse model in which constitutive epidermal extracellular-signal-regulated kinase-MAP-kinase signalling results in epidermal inflammation, and skin wounding induces tumours. We show that tumour incidence correlates with wound size and inflammatory infiltrate. Ablation of tumour necrosis factor receptor (TNFR)-1/-2, Myeloid Differentiation primary response gene 88 or Toll-like receptor (TLR)-5, the bacterial flagellin receptor, but not other innate immune sensors, in radiosensitive leukocytes protects against tumour formation. Antibiotic treatment inhibits, whereas injection of flagellin induces, tumours in a TLR-5-dependent manner. TLR-5 is also involved in chemical-induced skin carcinogenesis in wild-type mice. Leukocytic TLR-5 signalling mediates upregulation of the alarmin HMGB1 (High Mobility Group Box 1) in wound-induced papillomas. HMGB1 is elevated in tumours of patients with Recessive Dystrophic Epidermolysis Bullosa, a disease characterized by chronic skin damage. We conclude that in our experimental model the combination of bacteria, chronic inflammation and wounding cooperate to trigger skin cancer.

A critical reappraisal of the current data on drug-induced linear immunoglobulin A bullous dermatosis: A real and separate nosological entity?

BACKGROUND Linear IgA disease (LAD) has been associated with a variety of drugs over the past 30 years. OBJECTIVE To review current literature on all available cases of drug-induced LAD, in order to ascertain whether a close relationship is justified, so that it constitutes a real and separate nosological entity. METHODS The PubMed database was searched for all articles written in English related to drug-induced LAD published between January 1980 and December 2010. RESULTS The literature review shows that at least 84 articles were published, describing a total of 103 patients. Of these articles, only 46, from 13 countries, were included in this analysis, with a total of 52 patients: 24 (46.2%) were believed to be induced by vancomycin and 28 (53.8%) by drugs other than vancomycin. Challenge-dechallenge-rechallenge testing protocol was performed on only 6 (11.5%) of 52 patients, of which only 5 showed a positive result, while the Naranjo algorithm was performed on only 2 of them (0.3%). LIMITATIONS The evidence of this review analysis is based only on case reports. No study on large samples of drug-induced LAD is currently available. CONCLUSIONS The literature analysis reveals no strong scientific evidence to support the notion that some drugs have induced LAD; therefore in many reviewed cases, we must question whether drug-induced LAD is really the underlying entity. Further and thorough investigations using one of the available algorithms for adverse drug reaction are warranted.

The molecular basis of dystrophic epidermolysis bullosa in Mexico.

Background Type VII collagen gene (COL7A1) mutations are the cause of dystrophic epidermolysis bullosa (DEB), but most mutations are specific to individual families, and there are limited data on the nature of COL7A1 mutations in certain ethnic populations.

Management of cutaneous squamous cell carcinoma in patients with epidermolysis bullosa: best clinical practice guidelines

This article summarizes recommendations reached following a systematic literature review and expert consensus on the diagnosis and management of cutaneous squamous cell carcinomas in people with epidermolysis bullosa. The guidelines are intended to help inform decision making by clinicians dealing with this complex complication of a devastating disease.

Position effect on FGF13 associated with X-linked congenital generalized hypertrichosis

X-linked congenital generalized hypertrichosis (Online Mendelian Inheritance in Man 307150) is an extremely rare condition of hair overgrowth on different body sites. We previously reported linkage in a large Mexican family with X-linked congenital generalized hypertrichosis cosegregating with deafness and with dental and palate anomalies to Xq24-27. Using SNP oligonucleotide microarray analysis and whole-genome sequencing, we identified a 389-kb interchromosomal insertion at an extragenic palindrome site at Xq27.1 that completely cosegregates with the disease. Among the genes surrounding the insertion, we found that Fibroblast Growth Factor 13 (FGF13) mRNA levels were significantly reduced in affected individuals, and immunofluorescence staining revealed a striking decrease in FGF13 localization throughout the outer root sheath of affected hair follicles. Taken together, our findings suggest a role for FGF13 in hair follicle growth and in the hair cycle.

Mutations in the Cholesterol Transporter Gene ABCA5 Are Associated with Excessive Hair Overgrowth

Inherited hypertrichoses are rare syndromes characterized by excessive hair growth that does not result from androgen stimulation, and are often associated with additional congenital abnormalities. In this study, we investigated the genetic defect in a case of autosomal recessive congenital generalized hypertrichosis terminalis (CGHT) (OMIM135400) using whole-exome sequencing. We identified a single base pair substitution in the 5′ donor splice site of intron 32 in the ABC lipid transporter gene ABCA5 that leads to aberrant splicing of the transcript and a decrease in protein levels throughout patient hair follicles. The homozygous recessive disruption of ABCA5 leads to reduced lysosome function, which results in an accumulation of autophagosomes, autophagosomal cargos as well as increased endolysosomal cholesterol in CGHT keratinocytes. In an unrelated sporadic case of CGHT, we identified a 1.3 Mb cryptic deletion of chr17q24.2-q24.3 encompassing ABCA5 and found that ABCA5 levels are dramatically reduced throughout patient hair follicles. Collectively, our findings support ABCA5 as a gene underlying the CGHT phenotype and suggest a novel, previously unrecognized role for this gene in regulating hair growth.

Three cases of de novo dominant dystrophic epidermolysis bullosa associated with the mutation G2043R in COL7A1

In the absence of a positive family history, it is often difficult to determine whether a single case of mild‐to‐moderately severe dystrophic epidermolysis bullosa (DEB) represents autosomal recessive or de novo dominant disease. Recent molecular analyses of the type VII collagen gene, COL7A1, have established that the vast majority of such cases are recessive in nature. Nevertheless, a small number of de novo dominant patients have been documented. In this report, we describe three further examples of de novo dominant disease. In each case the COL7A1 mutation comprised the same glycine substitution, G2043R. This mutation has previously been reported in both dominant DEB pedigrees and as a de novo phenomenon and is the most common COL7A1 mutation in dominant DEB throughout the world. These cases emphasize the importance of molecular analysis in providing accurate genetic counselling in this genodermatosis.

Congenital universal hypertrichosis with deafness and dental anomalies inherited as an X‐linked trait

We report a large Mexican kindred with a variant form of congenital universal hypertrichosis that is inherited in an apparent X‐linked recessive manner. In addition to the generalized hypertrichosis, the affected individuals have dental malformations and deafness. Males are more severely affected than females who exhibit only mild hypertrichosis, but not deafness or dental anomalies. Haplotype analysis in this pedigree revealed linkage to a 13‐cM region on chromosome Xq24‐q27.1 between markers GATA198A10 and DXS8106. Localization of the gene underlying this form of hypertrichosis is the initial step in identifying genes on the X chromosome that are involved in the control of hair growth and development.

Type VII collagen regulates expression of OATP1B3, promotes front-to-rear polarity and increases structural organisation in 3D spheroid cultures of RDEB tumour keratinocytes

ABSTRACT Type VII collagen is the main component of anchoring fibrils, structures that are integral to basement membrane homeostasis in skin. Mutations in the gene encoding type VII collagen COL7A1 cause recessive dystrophic epidermolysis bullosa (RDEB) an inherited skin blistering condition complicated by frequent aggressive cutaneous squamous cell carcinoma (cSCC). OATP1B3, which is encoded by the gene SLCO1B3, is a member of the OATP (organic anion transporting polypeptide) superfamily responsible for transporting a wide range of endogenous and xenobiotic compounds. OATP1B3 expression is limited to the liver in healthy tissues, but is frequently detected in multiple cancer types and is reported to be associated with differing clinical outcome. The mechanism and functional significance of tumour-specific expression of OATP1B3 has yet to be determined. Here, we identify SLCO1B3 expression in tumour keratinocytes isolated from RDEB and UV-induced cSCC and demonstrate that SLCO1B3 expression and promoter activity are modulated by type VII collagen. We show that reduction of SLCO1B3 expression upon expression of full-length type VII collagen in RDEB cSCC coincides with acquisition of front-to-rear polarity and increased organisation of 3D spheroid cultures. In addition, we show that type VII collagen positively regulates the abundance of markers implicated in cellular polarity, namely ELMO2, PAR3, E-cadherin, B-catenin, ITGA6 and Ln332.