Epidemiology of basal and cutaneous squamous cell carcinoma in the U.K. 2013-15: a cohort study.

BACKGROUND: Basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC), together known as keratinocyte cancers (KCs), are the commonest cancer in white ethnic populations. Recent improvements to registry data collection in England has allowed more accurate analysis of the epidemiology of BCC and cSCC and for the first time we are able to provide an accurate (representative) tumour burden for KC in the U.K. OBJECTIVES: To estimate the incidence of BCC and cSCC in the U.K. METHODS: A cohort of patients with KCs between 2013 and 2015 were identified using linkage to diagnostic codes derived from pathology reports collected into the national cancer registry. Data from England's cancer registry were combined with data from Scotland, Northern Ireland and Wales. European age-standardized incidence rates (EASRs) of the first BCC and cSCC per patient per annum (PPPA) were calculated. RESULTS: In the U.K, the EASR of the first BCC and cSCC PPPA in 2013-15 were 285 and 77 per 100 000 person years, respectively (211 120 KCs total in 2015). The mean annual percentage increase was 5% between 2013 and 2015 for both BCC and cSCC. By counting the first KC PPPA, we include an additional 51% KCs compared with the previous reporting technique which counts only the first BCC and cSCC in a patient's lifetime, yet it represents a probable underestimation of 5-11% of the true tumour count. CONCLUSIONS: Based on an improved methodology, a more representative incidence of KC is presented, which is essential to healthcare planning and will lead to improved understanding of the epidemiology of KC. What's already known about this topic? Keratinocyte cancers (KCs) are the most common cancers affecting white ethnic populations. The incidence of basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC) is increasing worldwide including the U.K., most commonly in elderly male Caucasian patients. These cancers are traditionally substantially underreported and frequently excluded from national cancer statistics. What does this study add? Using improved data collection methods in England and validated tumour-reporting techniques, we report the most accurate BCC and cSCC incidence data for the U.K. ever published. Identifying the first BCC and cSCC per patient per annum, the incidence of BCC and cSCC in the U.K. (excluding Wales) was 285 and 77 per 100 000 person years, respectively, between 2013 and 2015, with more than 210 000 KCs in the U.K. in 2015.

High levels of type VII collagen expression in recessive dystrophic epidermolysis bullosa cutaneous squamous cell carcinoma keratinocytes increases PI3K and MAPK signalling, cell migration and invasion.

BACKGROUND: Epidermolysis bullosa is a group of inherited skin fragility diseases varying in severity from mild scarring to infant mortality. Great efforts are being undertaken to develop therapeutic strategies to treat the more pernicious forms of this disease, particularly those associated with recessive, loss-of-function mutations. In such cases significant effort is directed toward delivering recombinant protein at levels sufficient to demonstrate clinical benefit. Recessive dystrophic epidermolysis bullosa (RDEB) predisposes patients to a high incidence of life-threatening cutaneous squamous cell carcinoma (cSCC). Mutations in the gene encoding type VII collagen, COL7A1, are the sole cause of this disease and conflicting reports concerning type VII collagen and COL7A1 in carcinogenesis exist. OBJECTIVES: To investigate potential oncogenic effects of expressing recombinant type VII collagen in patient cells. METHODS: We used retroviral transduction to introduce type VII collagen into keratinocytes derived from patients with and without RDEB. RESULTS: Retroviral expression of type VII collagen in cSCC keratinocytes established from patients with RDEB resulted in increased cell adhesion, migration and invasion coupled with a concurrent increase in PI3K and MAPK signalling. CONCLUSIONS: Our data suggest caution when formulating strategies where delivery of type VII collagen is likely to exceed levels seen under normal physiological conditions in a patient group with a higher inherent risk of developing skin cancer.

A surveillance model for skin cancer in organ transplant recipients: a 22-year prospective study in an ethnically diverse population.

Skin cancer is a frequent complication of organ transplantation. Current guidelines advise specialist skin surveillance but there are limited data on how these should be implemented. This study determines overall burden of cancer and relevant intervals for strategic surveillance in an ethnically diverse transplant population. Prospective data on time to first and subsequent cancers and cumulative burden with respect to defined risk factors were analyzed in a cohort of 1010 patients in a UK center over 22 years. Among 931 individuals transplanted >6 months (mean 10.3 years), 1820 skin cancers occurred in 267 (29%) individuals and were multiple in 66%. Cumulative incidence at 5, 10, 20 and 30 years was 11%, 25%, 54% and 74%, with median time to second, third and fourth cancers of 24, 14.7 and 8.4 months, respectively. Tumors were overwhelmingly squamous and basal cell carcinomas (73% and 24%, respectively). Skin phototype, ultraviolet radiation exposure, age at transplant and duration of transplant were significant risk predictors and were used to construct clinically relevant surveillance intervals. This study provides a comprehensive, prospective analysis of skin cancer morbidity and risk in an ethnically diverse transplant population from which we derive an evidence-based skin cancer surveillance program.

Missing links: Weber-Cockayne keratin mutations implicate the L12 linker domain in effective cytoskeleton function.

We have identified mutations in keratins K5 (Arg331Cys) and K14 (Val270Met) in two kinships affected by the dominantly-inherited skin blistering disease, Weber-Cockayne epidermolysis bullosa simplex (EBS-WC). Linkage analysis, DNA sequencing and clinical and ultrastructural analysis are combined to provide the first detailed description of classical EBS-WC. Both phenotypes show similar blistering on trauma, indicating that both mutations compromise the structural resilience of the basal keratinocytes by affecting the keratin cytoskeleton. The location of these mutations in the L12 linker, which bisects the alpha-helical rod region of intermediate filament proteins, identifies another keratin mutation cluster leading to hereditary skin fragility syndromes.

Mutations in the hair cortex keratin hHb6 cause the inherited hair disease monilethrix.

Pathogenic mutations in a large number of human epithelial keratins have been well characterized. However, analogous mutations in the hard alpha-keratins of hair and nail have not yet been described. Monilethrix is a rare autosomal dominant hair defect with variable expression. Hairs from affected individuals show a beaded structure of alternating elliptical nodes and constrictions (internodes). These internodes exhibit a high prospensity to weathering and fracture. Strong evidence that trichocyte keratin defects might underlie this hair disorder was provided by genetic linkage analyses that mapped this disease to the type-II keratin gene cluster on 12q13. All affected individuals from a four-generation British family with monilethrix, previously linked to the type-II keratin gene cluster, as well as three unrelated single monilethrix patients, exhibited a heterozygous point mutation in the gene for type-II hair cortex keratin hHb6, leading to lysine substitution of a highly conserved glutamic acid residue in the helix termination motif (Glu 410 Lys). In a three-generation French family with monilethrix of a milder and variable phenotype, we detected another heterozygous point mutation in the same glutamic acid codon of hHb6, which resulted in a conservative aspartic acid substitution (Glu 410 Asp). These mutations provide the first direct evidence for involvement of hair keratins in hair disease.

Mutations in the plakophilin 1 gene result in ectodermal dysplasia/skin fragility syndrome.

Members of the armadillo protein gene family, which includes plakoglobin and beta-catenin, have important functions in cytoskeleton/cell membrane interactions. These proteins may act as linker molecules at adherens junctions and desmosomes at the plasma membrane; in addition, they may have pivotal roles in signal transduction pathways and significant effects on cell behaviour during development. Here, we describe the first human mutations in one of these dual function proteins, plakophilin 1 (band-6 protein; refs 8-10). The affected individual has a complete absence of immunostaining for plakophilin 1 in the skin and is a compound heterozygote for autosomal-recessively inherited premature termination codons of translation on both alleles of the plakophilin 1 gene (PKP1). Clinically, there are features of both cutaneous fragility and congenital ectodermal dysplasia affecting skin, hair and nails. There is no evidence of significant abnormalities in other epithelia or tissues. Desmosomes in the skin are small and poorly formed with widening of keratinocyte intercellular spaces and perturbed desmosome/keratin intermediate filament interactions. The molecular findings and clinical observations in this patient attest to the dual importance of plakophilin 1 in both cutaneous cell-call adhesion and epidermal morphogenesis.

Plectin deficiency results in muscular dystrophy with epidermolysis bullosa.

We report that mutation in the gene for plectin, a cytoskeleton-membrane anchorage protein, is a cause of autosomal recessive muscular dystrophy associated with skin blistering (epidermolysis bullosa simplex). The evidence comes from absence of plectin by antibody staining in affected individuals from four families, supportive genetic analysis (localization of the human plectin gene to chromosome 8q24.13-qter and evidence for disease segregation with markers in this region) and finally the identification of a homozygous frameshift mutation detected in plectin cDNA. Absence of the large multifunctional cytoskeleton protein plectin can simultaneously account for structural failure in both muscle and skin.

High-resolution genomic profiling of human papillomavirus-associated vulval neoplasia.

BACKGROUND: The incidence of human papillomavirus-associated vulval neoplasia is increasing worldwide; yet the associated genetic changes remain poorly understood. METHODS: We have used single-nucleotide polymorphism microarray analysis to perform the first high-resolution investigation of genome-wide allelic imbalance in vulval neoplasia. Our sample series comprised 21 high-grade vulval intraepithelial neoplasia and 6 vulval squamous cell carcinomas, with paired non-lesional samples used to adjust for normal copy number variation. RESULTS: Overall the most common recurrent aberrations were gains at 1p and 20, with the most frequent deletions observed at 2q, 3p and 10. Copy-neutral loss of heterozygosity at 6p was a recurrent event in vulval intraepithelial neoplasia. The pattern of genetic alterations differed from the characteristic changes we previously identified in cutaneous squamous cell carcinomas. Vulval neoplasia samples did not exhibit gain at 5p, a frequent recurrent aberration in a series of cervical tumours analysed elsewhere using an identical protocol. CONCLUSION: This series of 27 vulval samples comprises the largest systematic genome-wide analysis of vulval neoplasia performed to date. Despite shared papillomavirus status and regional proximity, our data suggest that the frequency of certain genetic alterations may differ in vulval and cervical tumours.

Binding of integrin alpha6beta4 to plectin prevents plectin association with F-actin but does not interfere with intermediate filament binding.

Hemidesmosomes are stable adhesion complexes in basal epithelial cells that provide a link between the intermediate filament network and the extracellular matrix. We have investigated the recruitment of plectin into hemidesmosomes by the alpha6beta4 integrin and have shown that the cytoplasmic domain of the beta4 subunit associates with an NH(2)-terminal fragment of plectin that contains the actin-binding domain (ABD). When expressed in immortalized plectin-deficient keratinocytes from human patients with epidermol- ysis bullosa (EB) simplex with muscular dystrophy (MD-EBS), this fragment is colocalized with alpha6beta4 in basal hemidesmosome-like clusters or associated with F-actin in stress fibers or focal contacts. We used a yeast two-hybrid binding assay in combination with an in vitro dot blot overlay assay to demonstrate that beta4 interacts directly with plectin, and identified a major plectin-binding site on the second fibronectin type III repeat of the beta4 cytoplasmic domain. Mapping of the beta4 and actin-binding sites on plectin showed that the binding sites overlap and are both located in the plectin ABD. Using an in vitro competition assay, we could show that beta4 can compete out the plectin ABD fragment from its association with F-actin. The ability of beta4 to prevent binding of F-actin to plectin explains why F-actin has never been found in association with hemidesmosomes, and provides a molecular mechanism for a switch in plectin localization from actin filaments to basal intermediate filament-anchoring hemidesmosomes when beta4 is expressed. Finally, by mapping of the COOH-terminally located binding site for several different intermediate filament proteins on plectin using yeast two-hybrid assays and cell transfection experiments with MD-EBS keratinocytes, we confirm that plectin interacts with different cytoskeletal networks.

Aberrant integrin expression during epidermal wound healing and in psoriatic epidermis.

We have examined integrin expression during the remodeling of the epidermis that takes place during wound healing, using a suction blister model in which the epidermis is detached from the dermis, leaving the basement membrane intact. By immunofluorescence microscopy, we found that the same integrin subunits were expressed during wound healing as in normal epidermis with very little change in the relative intensity or distribution of staining at the leading edge of the migrating epidermis. However, at the time of wound closure, when the epidermis is still hyperproliferative, alpha 2, alpha 3, alpha 6, and beta 1 were no longer confined to the basal layer, as in normal epidermis, but were also found in all the living suprabasal cell layers, coexpressed with the terminal differentiation markers involucrin, keratin 10, and keratin 16. Strong suprabasal staining for alpha v was also found in one specimen. beta 4, which normally forms a heterodimer with alpha 6, and alpha 5 remained predominantly basal. Three of the integrin ligands, fibronectin, type IV collagen, and laminin, remained largely confined to the basement membrane zone and dermis. By 14 d after wounding, the integrins were once more restricted to the basal layer. Suprabasal integrin expression was also observed in involved psoriatic lesions. Thus, in two situations in which the epidermis is hyperproliferative, there is a failure to downregulate integrin expression on initiation of terminal differentiation. The functional consequences of this aberrant integrin expression remain to be explored.

Loss of desmoplakin isoform I causes early onset cardiomyopathy and heart failure in a Naxos-like syndrome.

BACKGROUND: Desmosomes are cellular junctions important for intercellular adhesion and anchoring the intermediate filament (IF) cytoskeleton to the cell membrane. Desmoplakin (DSP) is the most abundant desmosomal protein with 2 isoforms produced by alternative splicing. METHODS: We describe a patient with a recessively inherited arrhythmogenic dilated cardiomyopathy with left and right ventricular involvement, epidermolytic palmoplantar keratoderma, and woolly hair. The patient showed a severe heart phenotype with an early onset and rapid progression to heart failure at 4 years of age. RESULTS: A homozygous nonsense mutation, R1267X, was found in exon 23 of the desmoplakin gene, which results in an isoform specific truncation of the larger DSPI isoform. The loss of most of the DSPI specific rod domain and C-terminal area was confirmed by Western blotting and immunofluorescence. We further showed that the truncated DSPI transcript is unstable, leading to a loss of DSPI. DSPI is reported to be an obligate constituent of desmosomes and the only isoform present in cardiac tissue. To address this, we reviewed the expression of DSP isoforms in the heart. Our data suggest that DSPI is the major cardiac isoform but we also show that specific compartments of the heart have detectable DSPII expression. CONCLUSIONS: This is the first description of a phenotype caused by a mutation affecting only one DSP isoform. Our findings emphasise the importance of desmoplakin and desmosomes in epidermal and cardiac function and additionally highlight the possibility that the different isoforms of desmoplakin may have distinct functional properties within the desmosome.

Phosphorylated human keratinocyte ornithine decarboxylase is preferentially associated with insoluble cellular proteins.

Ornithine decarboxylase (ODC), the first enzyme in polyamine biosynthesis, is highly regulated by many trophic stimuli, and changes in its levels and organization correlate with cytoskeletal changes in normal human epidermal keratinocytes (NHEK). NHEK ODC exhibits a filamentous perinuclear/nuclear localization that becomes more diffuse under conditions that alter actin architecture. We have thus asked whether ODC colocalizes with a component of the NHEK cytoskeleton. Confocal immunofluorescence showed that ODC distribution in NHEK was primarily perinuclear; upon disruption of the actin cytoskeleton with cytochalasin D, ODC distribution was diffuse. The ODC distribution in untreated NHEK overlapped with that of keratin in the perinuclear but not cytoplasmic area; after treatment with cytochalasin D, overlap between staining for ODC and for keratin was extensive. No significant overlap with actin and minimal overlap with tubulin filament systems were observed. Subcellular fractionation by sequential homogenizations and centrifugations of NHEK lysates or detergent and salt extractions of NHEK in situ revealed that ODC protein and activity were detectable in both soluble and insoluble fractions, with mechanical disruption causing additional solubilization of ODC activity (three- to sevenfold above controls). Fractionation and ODC immunoprecipitation from [(32)P]orthophosphate-labeled NHEK lysates showed that a phosphorylated form of ODC was present in the insoluble fractions. Taken together, these data suggest that two pools of ODC exist in NHEK. The first is the previously described soluble pool, and the second is enriched in phospho-ODC and associated with insoluble cellular material that by immunohistochemistry appears to be organized in conjunction with the keratin cytoskeleton.

Human papillomavirus infections in nonmelanoma skin cancers from renal transplant recipients and nonimmunosuppressed patients.

BACKGROUND: Nonmelanoma carcinomas of the skin represent the most frequent cancers among the Caucasian population worldwide. They occur with high frequency in renal allograft recipient patients after prolonged immunosuppression. PURPOSE: We analyzed tumors obtained from both immunosuppressed and nonimmunosuppressed patients for human papillomavirus (HPV) DNA. METHODS: Twenty-nine specimens of nonmelanoma carcinomas of the skin were obtained from 19 renal allograft recipient patients; these included 20 specimens of squamous cell carcinoma (SCC) from 11 patients, five specimens of basal cell carcinoma (BCC) from four patients, and four specimens of carcinoma in situ (CIS) from four patients. Forty-one specimens of nonmelanoma carcinomas of the skin were obtained from 32 nonimmunosuppressed patients; these included 26 SCC specimens from 19 patients, 11 BCC specimens from nine patients, and four keratoacanthoma (benign epithelial tumor) specimens from four patients. A polymerase chain reaction method involving use of degenerate oligonucleotide primers, in which the conserved region of the open reading frame of the HPV L1 (major capsid protein) gene is amplified, was used to amplify total cellular DNA purified from individual tumors. The DNA of each specimen was subjected to 16 different amplification reactions; different primer combinations were used in order to increase the sensitivity and specificity of HPV detection. Resulting products were probed with a radioactively labeled, degenerate oligonucleotide. HPV-specific DNA was either sequenced directly after elution from the gel or amplified with semi-nested, degenerate primers, after which the products were cloned and sequenced. Sequences were compared with all known papillomavirus sequences. RESULTS: Thirteen (65%) of the 20 SCC specimens and three of the five BCC specimens from immunosuppressed (renal allograft recipient) patients contained identifiable HPV-related sequences, among them 13 putative novel HPV genomes. In addition, all other malignant tumor specimens from this patient group revealed faint signals upon amplification and hybridization; the origin of these signals has not been identified in the present study. In nonimmunosuppressed patients, eight (31%) of 26 SCC specimens and four (36%) of 11 BCC specimens contained sequences of HPV types. Two putative novel HPV sequences could be identified in this group. Faint signals of yet undetermined origin were observed in eight of the SCC specimens and in two of the BCC specimens. Two of four keratoacanthoma specimens contained sequences of known HPV type. (Keratoacanthoma is a nonmalignant lesion for which the natural history has not been defined.) The spectrum of HPV types in both groups of patients differed substantially. CONCLUSIONS: These data point to the frequent presence of HPV sequences in SCCs and BCCs of the skin. The etiologic relationship of these infections to the respective malignant tumors remains to be evaluated. IMPLICATIONS: The presence of HPV DNA in a large percentage of specimens of nonmelanoma carcinomas of the skin from immunosuppressed patients, as well as from nonimmmunosuppressed patients, renders a papillomavirus infection as a possible factor in the etiology of this disease.

Specific types of human papillomavirus found in benign proliferations and carcinomas of the skin in immunosuppressed patients.

A total of 118 biopsies from skin lesions of 46 renal allograft patients was analyzed for human papillomavirus (HPV) DNA by polymerase chain reaction with degenerate primers and also partially by subsequent sequencing of the amplified fragment. Sixty-two % of the benign proliferations (31 of 50) contained DNA of known HPV types as well as HPV sequences related to a number of epidermodysplasia verruciformis-associated HPV types. HPV DNA sequences were found in 14 (56%) of 25 biopsies from squamous cell and basal cell carcinomas. One squamous cell carcinoma contained HPV 41 DNA. A novel 640-base pair fragment sharing homology with HPV 29 (82.7%) was found in 15% (3 of 20) of squamous cell carcinomas, in 9.4% (3 of 32) of dysplastic warts and in 8.5% (4 of 47) common warts. The remaining positive carcinoma biopsies contained HPV-related DNA in such a low copy number that additional analysis is required. The identification of new HPV types in skin cancers of immunosuppressed patients (other than epidermodysplasia verruciformis patients) further expands the spectrum of HPV-linked human malignancies and permits new approaches to study the pathogenesis of skin cancers.

Malignant transformation of cutaneous lesions in renal allograft patients: a role for human papillomavirus.

Renal allograft recipients are at greatly increased risk of developing squamous cell carcinomas. As these frequently arise adjacent to areas of multiple viral warts, we have investigated a possible role for human papillomavirus in malignant transformation within this population. We established, as primary cultures, keratinocytes from 24 lesions of varying degrees of squamous atypia from 9 patients. Ten of 14 cultures screened for the presence of episomal human papillomavirus DNA were positive using a mixed probe for cutaneous human papillomaviruses, although episomal copy was universally lost with continued passage. Three cultures, 2 of which were derived from malignant tissue and 1 from a benign lesion, were positive when screened with a probe for potentially oncogenic human papillomavirus DNAs 5 or 8. Both positive cultures of malignant origin exhibited extended lifespan and have been briefly characterized by morphology and growth requirements.