Desmosomes in Developing Human Epidermis

Desmosomes play important roles in the cell differentiation and morphogenesis of tissues. Studies on animal models have greatly increased our knowledge on epidermal development while reports on human developing skin are rare due to the difficult accessibility to the samples. Although the morphology of periderm cells and the process how the epidermis develops very much resemble each other, the timetable and the final outcome of a mature human epidermis markedly differ from those of murine skin. Even the genetic basis of the junctional components may have profound differences between the species, which might affect the implementation of the data from animal models in human studies. The aim of this review is to focus on the development of human skin with special emphasis on desmosomes. Desmosomal development is mirrored in perspective with other simultaneous events, such as maturation of adherens, tight and gap junctions, and the basement membrane zone

The effect of estradiol, testosterone, and human chorionic gonadotropin on the proliferation of Schwann cells with NF1 +/− or NF1 −/− genotype derived from human cutaneous neurofibromas

Dermal neurofibromas are the hallmarks of neurofibromatosis type 1 (NF1). Neurofibromas harbor Schwann cells with two different genotypes: Schwann cells which carry the germline mutation and a healthy NF1 allele (NF1 +/−), and a subpopulation of Schwann cells which harbor the so-called second hit leading to inactivation of both NF1 alleles (NF1 −/−). The second hit in the NF1 gene of Schwann cells is considered to be the initial step in the development of neurofibromas. Dermal neurofibromas typically start to grow in puberty, and their number and size increase during pregnancy, indicating hormone responsiveness. This is the first study to address the effect of human chorionic gonadotropin (hCG) on the proliferation of human NF1 +/− and NF1 −/− Schwann cells in vitro. In addition, the effects of estradiol and testosterone were also investigated. The results showed that NF1 −/− Schwann cells were more sensitive to estradiol, testosterone, and human chorionic gonadotropin than NF1 +/− cells. Specifically, the proliferation of NF1 −/− Schwann cells was increased by up to 99, 110, and 170% compared to vehicle control when treated with estradiol, testosterone, and hCG, respectively. Interestingly, no effect of estradiol, testosterone, or hCG on the proliferation of the cells with NF1 +/− genotype was observed. To conclude, the somatic second hit in the NF1 gene sensitizes Schwann cells to sex hormones resulting in a highly increased proliferation. Our results highlight the significance of sex hormones in the regulation of neurofibroma growth.</p

Treatment of cutaneous neurofibromas with carbon dioxide laser: Technique and patient experience

Cutaneous neurofibromas (cNF) are one of the hallmarks of neurofibromatosis 1 (NF1). The number of cNFs varies between individuals from a few to hundreds or even thousands and increases throughout adult life. cNFs cause a significant disease burden to adult patients and constitute an unmet need for therapy, since they may cause itch and pain and, being conspicuous and unsightly, stigmatize the patient. There is a lack of reports on how the outcome of various treatment options are perceived by the patients. Here we describe a technique for cNF removal using CO2 laser, and report how patients experience the procedure. Questionnaires were sent to patients who had had CO2 laser surgery in the French Referral Center for Neurofibromatoses, and in the Turku University Hospital, Finland, to retrospectively evaluate the patients’ global satisfaction of the procedure, treatment indications, and reasons for withdrawal from treatment, if this was the case. The number of returned questionnaires was 233/473 in France and 23/27 in Finland. The results showed that the most important indications for cNF removal were esthetic, and pain and itch caused by the tumors. In general, the procedure was well tolerated, and the degree of satisfaction was 8–10 on a scale from 0 to 10. For those 30% who discontinued the tumor removal program, the main reasons were organizational constraints, a non-satisfactory esthetic result, too many cNFs to treat, or problems with healing. Thus, the CO2 laser method is well tolerated but does not fully answer to the needs of the patients. Since medical treatment is not yet available, we encourage the use of laser removal of cNFs as a feasible method to decrease the tumor burden of the patients.</p

A rare disease and education: Neurofibromatosis type 1 decreases educational attainment

Rare heritable syndromes may affect educational attainment. Here, we study education in neurofibromatosis 1 (NF1) that is associated with multifaceted medical, social and cognitive consequences. Educational attainment in the Finnish population‐based cohort of 1408 individuals with verified NF1 was compared with matched controls using Cox proportional hazards model with delayed entry and competing risk for death. Moreover, models accounting for the effects of cancer at age 15–30 years, parental NF1 and developmental disorders were constructed. Overall, the attainment of secondary education was reduced in individuals with NF1 compared to controls (hazard ratio 0.83, 95%CI 0.74–0.92). History of cancer and developmental disorders were major predictors of lack of secondary education. Individuals with NF1 obtained vocational secondary education more often than general upper secondary education. Consequently, NF1 decreased the attainment of Bachelor's and Master's degrees by 46%–49% and 64%–74%, respectively. Surprisingly, the non‐NF1 siblings of individuals with NF1 also had lower educational attainment than controls, irrespective of parental NF1. In conclusion, NF1 is associated with reduced educational attainment and tendency for affected individuals to obtain vocational instead of academic education. Individuals living with NF1, especially those with cancer, developmental disorders or familial NF1, need effective student counseling and learning assistance.</p

Pediatric malignancies in neurofibromatosis type 1 : A population-based cohort study

Neurofibromatosis type 1 (NF1) is a cancer predisposition syndrome with an incidence of 1:2,000. Patients with NF1 have an increased cancer risk and mortality, but there are no population-based cohort studies specifically investigating the risk of childhood malignancies. We used the Finnish NF1 cohort to analyze the incidence, risk and prognosis of malignancies in NF1 patientsPeer reviewe

Intestinal tumors in neurofibromatosis 1 with special reference to fatal gastrointestinal stromal tumors (GIST)

Background Type 1 neurofibromatosis (NF1) is a genetic tumor predisposing Rasopathy. NF1 patients have an increased risk for developing benign and malignant tumors, but the occurrence of intestinal tumors has not been investigated at the population level. Methods In this retrospective register-based total population study, diagnoses of gastrointestinal tract tumors were retrieved from the Finnish Care Register for Health Care for 1,410 NF1 patients and 14,030 reference persons. We also reviewed the death certificates of 232 NF1 patients who died during years 1987-2013, and specifically searched for diagnosis of gastrointestinal stromal tumor (GIST). Results The register analysis revealed an increased overall hazard ratio (HR) of 2.6 (95% CI 1.9-3.6) for intestinal tumors in NF1 compared to general population. The highest HR of 15.6 (95% CI 6.9-35.1) was observed in the small intestine. The focused analysis of NF1 death certificates and GISTs demonstrated that the GIST was the primary cause of death in seven patients. Conclusion This study emphasizes the need for careful evaluation of NF1 patients with gastrointestinal complaints. The challenge in diagnosis is that the tumors preferably occur at the small intestine, which is difficult target for diagnostic procedures. We also show that the NF1 GISTs may lead to fatal outcome despite of benign histopathological findings at the time of the diagnosis.</p

Circulating free DNA in the plasma of individuals with neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is an autosomal dominant syndrome whose characteristic manifestations include benign neurofibromas, yet NF1 is also associated with a high risk of cancer. Measurements of circulating free plasma DNA (cfDNA) are gaining wider applicability in cancer diagnostics, targeting of therapy, and monitoring of therapeutic response. Individuals with NF1 are likely to be followed up using this method, but the effects of NF1 and neurofibromas on cfDNA levels are not known. We studied peripheral blood samples from 19 adults with NF1 and 12 healthy controls. The cfDNA was isolated from plasma with QIAamp Circulating Nucleic Acid Kit and quantified using the Qubit 2.0 Fluorometer. The cfDNA concentration of each sample was normalized relative to the plasma protein concentration. The normalized median concentration of cfDNA in plasma was 19.3 ng/ml (range 6.6–78.6) among individuals with NF1 and 15.9 ng/ml (range 4.8–47.0) among controls (p = .369). Individuals with NF1 who also had plexiform neurofibroma (pNF) showed non‐significantly elevated cfDNA concentration compared to individuals with NF1 and without known pNF (median 25.4 vs. 18.8 ng/ml, p = .122). The effect of NF1 on cfDNA seems to be relatively small and NF1 is therefore unlikely to hamper the use of cfDNA‐based assays.</p

Congenital anomalies in neurofibromatosis 1: a retrospective register-based total population study

Background: Neurofibromatosis type 1 (NF1) is a dominantly inherited Rasopathy caused by mutations in the NF1 gene on chromosome 17. NF1 has been connected to congenital anomalies, e.g., in the skeletal and cardiovascular systems, but the overall incidence of anomalies is unknown. In this retrospective register-based total population study conducted in Finland, the congenital anomalies in NF1 were evaluated.Methods: One thousand four hundred ten patients with NF1 were identified by searching the medical records related to inpatient and outpatient hospital visits of patients with an associated diagnosis for NF1 in 1987-2011. Each diagnosis was confirmed by a thorough review of the medical records. Ten non-NF1 control persons per NF1 patient were collected from the Population Register Centre. NF1 patients and controls were linked to the Medical Birth Register and the Register of Congenital Malformations. Odds ratios (OR) and 95% confidence intervals (95% CI) for major congenital anomalies (MCA) were calculated.Results: The OR for at least one MCA among NF1 children was almost threefold (adjusted OR 2.78, 95% CI 1.71-4.54) compared to controls matched for age, sex and municipality. NF1 children had a significantly increased risk of congenital anomalies in the circulatory (adjusted OR 3.35, 95% CI 1.64-6.83), urinary (adjusted OR 4.26, 95% CI 1.36-13.35) and musculoskeletal (adjusted OR 2.77, 95% CI 1.09-7.02) systems. Also, anomalies of the eye, ear, head and neck were more common among NF1 children than controls (adjusted OR 4.66, 95% CI 1.42-15.31). Non-NF1 children of mothers with NF1 did not have more anomalies than controls (adjusted OR 0.53, 95% CI 0.13-2.21).Conclusions: Children with NF1 have more MCAs than controls and close follow-up during pregnancy and the neonatal period is required if the mother or father has NF1. Non-NF1 children of mothers with NF1 do not have an increased risk for anomalies

Complement Component C3 and Complement Factor B Promote Growth of Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (cSCC) is one of the most common metastatic skin cancers with increasing incidence. We examined the roles of complement component C3 and complement factor B (CFB) in the growth of cSCC. Analysis of cSCC cell lines (n = 8) and normal human epidermal kerati-nocytes (n = 11) with real-time quantitative PCR and Western blotting revealed up-regulation of C3 and CFB expression in cSCC cells. Immunohistochemical staining revealed stronger tumor cell specific Labeling for C3 and CFB in invasive cSCCs (n = 71) and recessive dystrophic epidermolysis bullosa-associated cSCCs (n = 11) than in cSCC in situ (n = 69), actinic keratoses (n = 63), and normal skin (n = 5). Significant up-regulation of C3 and CFB mRNA expression was noted in chemically induced mouse cSCCs, compared to benign papillomas. Knockdown of C3 and CFB expression inhibited migration and proliferation of cSCC cells and resulted in potent inhibition of extracellular signal regulated kinase 1/2 activation. Knockdown of C3 and CFB markedly inhibited growth of human cSCC xenograft tumors in vivo. These results provide evidence for the rotes of C3 and CFB in the development of cSCC and identify them as biomarkers and potential therapeutic targets in this metastatic skin cancer.Peer reviewe