Loss-of-function mutation in DSG1 underlies focal palmoplantar keratoderma

Dysregulation of FOXD2-AS1 promotes cell proliferation and migration and predicts poor prognosis in oral squamous cell carcinoma: a study based on TCGA data

FOXD2 adjacent opposite strand RNA 1 (FOXD2-AS1) plays an important role in the pathogenesis of some cancers. However, its functional role in oral squamous cell carcinoma (OSCC) remains largely unknown. In this study, we conducted expressional and functional analyses of FOXD2-AS1 using data from the Cancer Genome Atlas (TCGA) and in vitro OSCC assays. FOXD2-AS1 dysregulation was remarkably associated with radiation therapy, anatomic location, high histologic grade, and lymphovascular invasion (P < 0.05). A nomogram based on FOXD2-AS1 expression was constructed for use as a diagnostic indicator for OSCC patients, and multivariate cox regression analysis showed that FOXD2-AS1 expression was an independent prognostic factor for OSCC patients. KEGG, gene set enrichment analysis, and immune infiltration evaluations indicated that FOXD2-AS1 was involved in tumor progression via epithelial-to-mesenchymal transition and cell cycle regulation and was negatively associated with mast cell, DCs, iDCs, and B cells. FOXD2-AS1 silencing suppressed the proliferation and migration of Cal27 cells. Our findings showed that an aberrantly high FOXD2-AS1 expression predicts poor prognosis in OSCC; FOXD2-AS1 may act as an oncogenic protein by regulating cell proliferation and migration and may suppress adaptive immunity by modulating the number and function of antigen-presenting cells.

Mutations in genes encoding desmosomal proteins: spectrum of cutaneous and extracutaneous abnormalities

The desmosome is a type of intercellular junction found in epithelial cells, cardiomyocytes and other specialized cell types. Composed of a network of transmembranous cadherins and intracellular armadillo, plakin and other proteins, desmosomes contribute to cell-cell adhesion, signalling, development and differentiation. Mutations in genes encoding desmosomal proteins result in a spectrum of erosive skin and mucosal phenotypes that also may affect hair or heart. This review summarizes the molecular pathology and phenotypes associated with desmosomal dysfunction with a focus on inherited disorders that involve the skin/hair, as well as associated extracutaneous pathologies. We reviewed the relevant literature to collate studies of pathogenic human mutations in desmosomes that have been reported over the last 25 years. Mutations in 12 different desmosome genes have been documented, with mutations in nine genes affecting the skin/mucous membranes (DSG1, DSG3, DSC2, DSC3, JUP, PKP1, DSP, CDSN, PERP) and eight resulting in hair abnormalities (DSG4, DSC2, DSC3, JUP, PKP1, DSP, CDSN, PERP). Mutations in three genes can result in cardiocutaneous syndromes (DSC2, JUP, DSP), although mutations have been described in five genes in inherited heart disorders that may lack any dermatological manifestations (DSG2, DSC2, JUP, PKP2, DSP). Understanding the diverse nature of these clinical phenotypes, as well as the desmosome gene mutation(s), has clinical value in managing and counselling patients, as well as demonstrating the biological role and activity of specific components of desmosomes in skin and other tissues.

AAGAB Mutations in 18 Canadian Families With Punctate Palmoplantar Keratoderma and a Possible Link to Cancer

BACKGROUND

Punctate palmoplantar keratoderma type 1 (PPPK1) presents in late childhood to adulthood with multiple small discrete hyperkeratotic papules on palms and soles. PPPK1 is an autosomal dominant skin disease caused by AAGAB mutations. It has been suggested that PPPK1 may be associated with an increased predisposition to systemic malignancies.

OBJECTIVES

To evaluate the presence of AAGAB mutations in Canadian families with PPPK1 and the possible increased predisposition to systemic malignancies.

METHODS

Eighteen unrelated Canadian families with PPPK1 were recruited for this study. Genomic DNA was extracted from saliva and PCR amplification was performed for all AAGAB exons and exon/intron junctions. PCR products were sequenced and analyzed for mutations. A family history of malignancy was obtained from the index case and, when possible, from other family members.

RESULTS

We have identified 5 heterozygous AAGAB loss of function mutations in 11 families. The mutation c.370 C>T, p.Arg124* was the most prevalent and was identified in 6 families. A splice site mutation, c.451+3delAAGT, was identified in 2 families. The other mutations c.473delG, p.Gly158Glufs*0; c.550-551insAAT, p.Gly183*; and c.505-506 dupAA, p.Asn169Lysfs*6 were each identified in 1 family. Different cancers were reported in 11 families (Table 1 and Supplemental Figure S1).

CONCLUSIONS

AAGAB mutations were found in 11 of 18 families with PPPK1. In some families there appears to be an association with cancer.