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2.
J Eur Acad Dermatol Venereol ; 35(7): 1528-1535, 2021 Jul.
Article in English | MEDLINE | ID: mdl-33656221

ABSTRACT

BACKGROUND: Cutaneous melanoma (CM) is a multifactorial disease, with both environmental and genetic factors involved. The incidence of CM has risen rapidly during the last decades, making it a growing public health problem. OBJECTIVES: The purpose of this retrospective study was to compare incidence and survival data of CM between two neighbouring countries, Belgium (BE) and the Netherlands (NL). METHODS: Data were collected by the Belgian Cancer Registry (BCR) and the Netherlands Cancer Registry (NCR) from 1 January 2004 until 31 December 2016. Mucosal melanoma, in situ CM and melanoma in children from 0 to 14 years were excluded. Age-standardized incidence rates were calculated using the World Standard Population (WSR) per 100 000 persons. Five-year relative survival ratios were calculated using the Ederer II methodology. RESULTS: Total number of CM was higher in NL (63 789) compared with BE (27 679). The WSR was 1.5 times higher in NL compared with BE (27.7 vs. 18.6/100 000/year). The WSR of stage IV tumours was higher in BE than in NL (0.3 vs. 0.2/100 000/year). Five-year relative survival of stage IV tumours was higher in BE compared with NL (27.2% vs. 13.7%). CONCLUSIONS: Incidence of CM was higher in NL, indicating a higher risk of CM diagnosis. Stage IV tumours were relatively more frequent in BE for both sexes, while relative survival of stage IV tumours was higher in BE. As geographical location and latitude of both neighbouring countries are almost identical, other factors like differences in behaviour, follow-up and/or treatment may explain these differences.


Subject(s)
Melanoma , Skin Neoplasms , Belgium/epidemiology , Child , Female , Humans , Incidence , Male , Melanoma/epidemiology , Netherlands/epidemiology , Registries , Retrospective Studies , Skin Neoplasms/epidemiology , Survival Rate
4.
Photochem Photobiol Sci ; 17(12): 1932-1940, 2018 Dec 05.
Article in English | MEDLINE | ID: mdl-29926025

ABSTRACT

Humans have been exposed to solar UV radiation since their appearance on Earth and evolution has enabled most individuals to adapt to this exposure, to some degree. UV radiation produces several deleterious effects in human skin and light-skinned individuals are at greatest risk for both acute and long-term negative effects such as DNA damage, sunburn, immune suppression and skin cancer. The benefits of photoadaptation, which leads to a decreased response after acclimatization, are that humans who have skin that is capable of photoadaptation can work and play in the sun with reduced fear of painful sunburn. However, the effects of photoadaptation on DNA damage and development of skin cancer are quite complex and less well-understood. In this article, we have reviewed the current state of knowledge of UVR photoadaptation in human skin. However, more studies are needed to explore the use of UVR photoadaptation to protect against critical endpoints, such as skin cancer.


Subject(s)
Skin/radiation effects , Ultraviolet Rays , Antioxidants/metabolism , DNA Damage/radiation effects , DNA Repair , Humans , Immunosuppression Therapy , Skin/metabolism , Skin Pigmentation/radiation effects , Sunburn/etiology
5.
BMC Cancer ; 17(1): 562, 2017 Aug 23.
Article in English | MEDLINE | ID: mdl-28835228

ABSTRACT

BACKGROUND: Previous studies have investigated the protective effect of vitamin D serum levels, at diagnosis and during the follow-up period after treatment, on melanoma outcome. In the present study we assess whether vitamin D supplementation, in the follow-up period after diagnosis and surgical resection of the primary tumor, has a protective effect on relapse of cutaneous malignant melanoma and whether this protective effect correlates with vitamin D levels in serum and Vitamin D Receptor immunoreactivity in the primary tumor. METHODS/DESIGN: This study is a multicenter randomized double blind placebo- controlled phase III trial. Patients between the age of 18 and 80 years diagnosed and treated surgically for a melanoma stage IB-III are eligible for randomization in a 1:1 ratio to active treatment or placebo. The study drug is taken each month and consists of either 100,000 International Unit cholecalciferol or arachidis oleum raffinatum used as a placebo. The primary endpoint is relapse free survival. The secondary endpoints are 25 hydroxyvitamin D3 serum levels at diagnosis and at 6 month intervals, melanoma subtype, melanoma site and stage of melanoma at diagnosis according to the 2009 American Joint Committee on Cancer melanoma staging and classification. At randomization a bloodsample is taken for DNA analysis. The study is approved by the local Ethics Committees. DISCUSSION: If we can confirm our hypothesis that vitamin D supplementation after removal of the tumor has a protective effect on relapse of cutaneous malignant melanoma we may reduce the burden of CMM at several levels. Patients, diagnosed with melanoma may have a better clinical outcome and improved quality of life. There will be a decrease in health care costs related to treatment of metastatic disease and there will be a decrease in loss of professional years, which will markedly reduce the economic burden of the disease. TRIAL REGISTRATION: Clinical Trial.gov, NCT01748448 , 05/12/2012.


Subject(s)
Clinical Protocols , Dietary Supplements , Melanoma/epidemiology , Skin Neoplasms/epidemiology , Vitamin D , Adolescent , Adult , Aged , Aged, 80 and over , Belgium/epidemiology , Calcifediol/blood , Disease Progression , Female , Health Knowledge, Attitudes, Practice , Humans , Male , Melanoma/etiology , Melanoma/mortality , Melanoma/pathology , Middle Aged , Neoplasm Staging , Patient Outcome Assessment , Receptors, Calcitriol/genetics , Receptors, Calcitriol/metabolism , Risk Factors , Skin Neoplasms/etiology , Skin Neoplasms/mortality , Skin Neoplasms/pathology , Vitamin D/administration & dosage , Vitamin D/adverse effects , Young Adult , Melanoma, Cutaneous Malignant
6.
J Eur Acad Dermatol Venereol ; 30(11): 1912-1918, 2016 Nov.
Article in English | MEDLINE | ID: mdl-27256411

ABSTRACT

BACKGROUND: Non-melanoma skin cancer (NMSC) is the most common type of cancer among Caucasians, however, few data exist on its incidence. Because of a sheer volume of these tumours, NMSC is often not systematically registered. OBJECTIVE: To describe and analyse the incidence of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) in Belgium. METHODS: Incidence data of BCC and SCC, including multiple primary skin tumours in the same patient, were extracted from the Belgian Cancer Registry from 2004 to 2012 (predominantly coming from pathology notifications). Belgian legislation makes cancer registration compulsory for oncological care programmes and for all pathological anatomy laboratories. RESULTS: Between 2004 and 2012, 113 254 BCC and 33 153 SCC cases were reported in Belgium. A total of 130 339 patients had 146 407 tumours. Approximately, 10% of the patients (12 759 patients) had multiple tumours. The world age-standardised incidence rate (WSR) for BCC increased from 36.9 in 2004 to 98.4 per 100 000 person years in 2012 for males and from 34.2 in 2004 to 102.0 in 2012 for females. For SCC, the WSR increased from 14.9 in 2004 to 24.7 in 2012 for males and from 6.8 in 2004 to 13.5 in 2012 for females. CONCLUSIONS: From 2004 to 2012, the incidence of BCC and SCC markedly rose in Belgium, as also seen worldwide. Known causes are increased sun exposure caused by changed sunlight-related behaviour (increased outdoor activities and holidays, use of tanning beds and changes in clothing style), ageing and improved registration. Because of their high and increasing incidence, these cancers will have major implications on healthcare planning and preventive measures. Therefore, we recommend compulsory registration, whenever is possible, of BCC and SCC, although it is an ambitious objective, especially in countries with a high burden of these tumours and in countries where registration is currently unavailable.


Subject(s)
Carcinoma, Basal Cell/epidemiology , Carcinoma, Squamous Cell/epidemiology , Skin Neoplasms/epidemiology , Aged , Belgium/epidemiology , Humans , Incidence
8.
J Eur Acad Dermatol Venereol ; 29(1): 61-8, 2015 Jan.
Article in English | MEDLINE | ID: mdl-24661317

ABSTRACT

BACKGROUND: BRAF inhibitors frequently cause significant cutaneous adverse reactions. OBJECTIVE: To study the timing, prevalence and response to treatment of skin lesions in patients receiving V-raf murine sarcoma viral oncogene homolog B1 (BRAF) inhibitors. METHODS: We prospectively studied the cutaneous side-effects of patients with a BRAF mutant (V600E, V600K, V600R) metastatic malignant melanoma treated with a BRAF inhibitor. We systematically registered prevalence, timing of onset and response to treatment. RESULTS: Twenty patients were treated for 2-52 weeks with a BRAF inhibitor. Eleven patients on vemurafenib (58%) developed cutaneous side-effects and 10 patients (42%) had more than one cutaneous adverse event. Verrucous papillomas were observed in eight patients (42%), after 1-12 weeks. We diagnosed four keratoacanthomas in two patients (11%) after 6-10 weeks and two squamous cell carcinomas in two patients (11%) after 10-16 weeks. Seven patients (37%) developed a hyperkeratotic, folliculocentric eruption after 2-8 weeks, resolving quickly under topical steroids. Four patients (21%) presented a facial erythema, two patients (11%) a seborrhoeic dermatitis-like eczema on the scalp. Three patients (16%) developed cystic lesions after 2-11 weeks. Three patients (16%) presented a hand-foot skin reaction after 4-6 weeks, which was successfully treated with topical steroids and keratolytics. Hyperkeratosis of the nipples was seen in one patient (5%). We observed phototoxic reactions after UV exposure in five patients (26%) and alopecia in two patients (11%) after 8-10 weeks. One patient on dabrafenib developed curly hairs (24 weeks), keratotic papules (1 and 36 weeks), a keratoacanthoma (4 weeks) and a hand-foot skin reaction (31 weeks). CONCLUSION: Multiple cutaneous toxicities were observed in patients under BRAF inhibitors, mostly well controlled with adequate treatment. We recommend a multidisciplinary approach with regular assessments of the skin by a dermatologist. This allows early identification and adequate treatment to avoid premature discontinuation of a life-prolonging therapy.


Subject(s)
Antineoplastic Agents/adverse effects , Indoles/adverse effects , Melanoma/drug therapy , Proto-Oncogene Proteins B-raf/antagonists & inhibitors , Skin Neoplasms/drug therapy , Sulfonamides/adverse effects , Adult , Aged , Aged, 80 and over , Alopecia/chemically induced , Carcinoma, Squamous Cell/chemically induced , Dermatitis, Phototoxic/etiology , Eczema/chemically induced , Erythema/chemically induced , Facial Dermatoses/chemically induced , Female , Hand-Foot Syndrome/etiology , Humans , Imidazoles/adverse effects , Keratoacanthoma/chemically induced , Male , Melanoma/genetics , Melanoma/secondary , Middle Aged , Oximes/adverse effects , Papilloma/chemically induced , Prospective Studies , Proto-Oncogene Proteins B-raf/genetics , Skin Neoplasms/genetics , Skin Neoplasms/pathology , Vemurafenib
9.
Br J Dermatol ; 171(5): 1014-21, 2014 Nov.
Article in English | MEDLINE | ID: mdl-24628329

ABSTRACT

BACKGROUND: Epithelial-mesenchymal transition (EMT) is required for tumour invasion and dissemination to occur. OBJECTIVES: To investigate EMT during invasion of cutaneous squamous cell carcinoma (cSCC) and the involvement of AKT. METHODS: Using a tissue microarray, we measured expression of EMT-markers and AKT activation in 140 samples from patients with skin cancer and matched samples of normal skin adjacent to cSCC in cSCC in situ (cSCCIS) and in invasive cSCC. We investigated EMT using functional assays and the expression of EMT markers in an isogenic skin cancer progression model using cell lines derived from dysplastic forehead skin (PM1), primary invasive cSCC (MET1) and its lymph node metastasis (MET4). This model was used to investigate AKT-specific inhibition of the EMT process. RESULTS: In comparison with normal skin, and normal skin plus cSCCIS, the invasive cSCCs show significantly increased vimentin expression, decreased E-cadherin expression and increased expression of the active form of AKT. In the cell culture model, the primary MET1 cells display the lowest adhesion potential, the highest migratory and invasive ability through a Matrigel-coated porous membrane, the highest expression of EMT markers vimentin and Slug and the lowest expression of the epithelial marker E-cadherin. Pharmacological AKT inhibition in this model suppressed EMT mechanisms. CONCLUSIONS: AKT may serve as a therapeutic target to avoid dissemination of cSCC cells.


Subject(s)
Biomarkers, Tumor/metabolism , Carcinoma, Squamous Cell/pathology , Epithelial-Mesenchymal Transition/physiology , Proto-Oncogene Proteins c-akt/metabolism , Skin Neoplasms/pathology , Cadherins/metabolism , Carcinoma, Squamous Cell/metabolism , Down-Regulation/physiology , Humans , Neoplasm Invasiveness , Proto-Oncogene Proteins c-akt/antagonists & inhibitors , Skin Neoplasms/metabolism , Snail Family Transcription Factors , Tissue Array Analysis , Transcription Factors/metabolism , Tumor Cells, Cultured , Up-Regulation/physiology , Vimentin/metabolism
10.
J Pharm Belg ; (1): 20-7, 2013 Mar.
Article in French | MEDLINE | ID: mdl-23638609

ABSTRACT

Adherence to therapy is low for topical therapy used in dermatological disorders. particularly in chronic diseases like atopic dermatitis and psoriasis. One of the reasons is that patients do not trust their therapy and fear side effects, particularly with topical corticosteroids. In order to make patients more confident, it is it important to provide correct and detailed information about the prescribed products and the amount to apply, to involve them in the implementation of therapy and to harmonize the information given by various care providers (physicians, nurses, pharmacists). The message needs to be clear and consistent between caregivers and not lead to unjustified worries. Poor adherence may result in the use of stronger preparations or switch to systemic treatment, which eventually will result in more severe side effects.


Subject(s)
Adrenal Cortex Hormones/therapeutic use , Anti-Inflammatory Agents/therapeutic use , Patient Compliance , Skin Diseases/drug therapy , Administration, Topical , Adrenal Cortex Hormones/administration & dosage , Adrenal Cortex Hormones/adverse effects , Anti-Inflammatory Agents/administration & dosage , Anti-Inflammatory Agents/adverse effects , Communication , Humans , Patient Education as Topic , Pharmacists
11.
Mult Scler ; 18(4): 451-9, 2012 Apr.
Article in English | MEDLINE | ID: mdl-21952096

ABSTRACT

BACKGROUND: Sunlight and vitamin D have been inversely associated with the risk of multiple sclerosis (MS). OBJECTIVE: We investigated sunlight exposure and sun sensitivity in relation to disability progression in MS. METHODS: We conducted a survey among persons with MS, registered by the Flemish MS society, Belgium, and stratified data according to relapsing-onset and progressive-onset MS. We used Kaplan-Meier survival and Cox proportional hazard regression analyses with time to Expanded Disability Status Scale (EDSS) 6 as outcome measure. Hazard ratios for the time from onset and from birth were calculated for the potentially predictive variables, adjusting for age at onset, gender and immunomodulatory treatment. RESULTS: 704 (51.3%) of the 1372 respondents had reached EDSS 6. In relapsing-onset MS, respondents reporting equal or higher levels of sun exposure than persons of the same age in the last 10 years had a decreased risk of reaching EDSS 6. In progressive-onset MS, increased sun sensitivity was associated with an increased hazard of reaching EDSS 6. CONCLUSION: The association of higher sun exposure with a better outcome in relapsing-onset MS may be explained by either a protective effect or reverse causality. Mechanisms underlying sun sensitivity might influence progression in progressive-onset MS.


Subject(s)
Multiple Sclerosis, Chronic Progressive/physiopathology , Multiple Sclerosis, Relapsing-Remitting/physiopathology , Sunlight , Adolescent , Adult , Age of Onset , Aged , Aged, 80 and over , Disability Evaluation , Disease Progression , Female , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Multiple Sclerosis, Chronic Progressive/diagnosis , Multiple Sclerosis, Relapsing-Remitting/diagnosis , Proportional Hazards Models , Risk , Severity of Illness Index , Surveys and Questionnaires , Young Adult
12.
Clin Exp Dermatol ; 35(6): 569-75, 2010 Aug.
Article in English | MEDLINE | ID: mdl-19874372

ABSTRACT

Deregulation of cell-death pathways plays a key role in the pathogenesis of various skin diseases. The different types of cell death are mainly defined by morphological criteria, and include apoptosis, autophagic cell death, and necrosis. The process of apoptosis is well characterized at the molecular level and involves the activation of two main pathways, the intrinsic and extrinsic pathways, converging into the execution of apoptosis by intracellular cysteine proteases, called caspases. The relevance and implication of these apoptotic pathways in the pathophysiology of skin diseases, such as toxic epidermal necrolysis, graft-versus-host disease and skin cancer, has been extensively studied. The role of autophagic cell death in progression of skin tumours and response to cytotoxic drugs is only beginning to be elucidated.


Subject(s)
Apoptosis/physiology , Autophagy/physiology , Signal Transduction/physiology , Skin Diseases/pathology , Humans , Necrosis/physiopathology , Skin Diseases/metabolism
13.
Int J Cosmet Sci ; 28(1): 1-7, 2006 Feb.
Article in English | MEDLINE | ID: mdl-18492196

ABSTRACT

Different adaptation mechanisms like heat shock response, cell cycle arrest and DNA repair, melanin pigmentation and thickening of the epidermis are present in the human skin to protect against the adverse effects of solar UV irradiation. When DNA damage is beyond repair, cells undergo apoptosis to prevent their replication. We discuss the current knowledge on these different adaptation mechanisms to UVB damage, the most energetic fraction of solar UV that reaches the skin. As p53 protein, the guardian of the genome, plays a key role in protective response to genotoxic damage, its role in this adaptive response of the skin to UV will be further discussed.

14.
J Eur Acad Dermatol Venereol ; 19(3): 332-9, 2005 May.
Article in English | MEDLINE | ID: mdl-15857460

ABSTRACT

BACKGROUND: Although numerous studies have evaluated risk factors associated with cutaneous malignant melanoma (CMM), no such study has been carried out in Belgium. OBJECTIVES: To identify individuals who are at high risk of developing malignant melanoma in Belgium, which could enhance the efficacy of screening interventions and avoid unnecessary skin inspections. STUDY DESIGN/SETTING/SUBJECTS: We prospectively included patients who were diagnosed with invasive malignant melanoma between 1998 and 2001 at the Department of Dermatology in a case-control study. Controls were selected from the outpatient dermatology clinic. Participants were interviewed and clinically examined by a dermatologist. We asked questions concerning most known risk factors associated with malignant melanoma such as phenotypical and skin characteristics, and environmental and lifestyle exposures. To adjust for confounding variables and to estimate odds ratios (ORs) and 95% confidence intervals (CIs), a multivariate model was used. RESULTS: Although sunburn in childhood and substantial occupational solar exposure were modestly, but significantly, associated with malignant melanoma risk, clinical examination yielded several stronger risk factors. In a multivariate model, which adjusted for age, gender and skin phototype, phenotypical characteristics such as skin, hair and eye colour were significantly associated with the development of malignant melanoma. In the multivariate model, people with three or more atypical naevi were at more than 10-fold risk of developing a malignant melanoma (> or = 3 atypical naevi; adjusted OR = 11.40, 95% CI = 4.79-17.53) compared to those without an atypical naevus. The presence of one or more palpable naevi on the upper extremities or having solar lentigines increased the odds of developing malignant melanoma at least twofold. CONCLUSIONS: In Belgium, risk factors associated with malignant melanoma appear to be in accordance with previous studies. To assess peoples' risk profile, clinical skin examination is likely to yield the most important sporadic malignant melanoma risk factors. Therefore, focusing screening campaigns on individuals with predefined findings on skin self-examination may increase its efficacy.


Subject(s)
Melanoma/etiology , Skin Neoplasms/etiology , Belgium , Case-Control Studies , Eye Color , Female , Hair Color , Humans , Male , Melanoma/diagnosis , Middle Aged , Multivariate Analysis , Nevus/complications , Phenotype , Prospective Studies , Risk Factors , Skin Neoplasms/diagnosis , Skin Pigmentation , Sunburn/complications , Sunlight/adverse effects
15.
J Eur Acad Dermatol Venereol ; 17(3): 340-3, 2003 May.
Article in English | MEDLINE | ID: mdl-12702082

ABSTRACT

We describe two patients in whom chronic radiodermatitis with therapy-resistant ulceration of the right scapular region developed, following percutaneous coronary intervention with fluoroscopic imaging. Contrary to most reported cases in the literature, which involve numerous cardiac catheterization procedures, in both patients described here the total radiation dose was given during two successive procedures, involving difficult and prolonged coronary intervention with stent implantation. In both cases, local treatment of the ulcerative lesions was insufficient, necessitating excision of the radiodermatitis area and replacement with a skin graft, with good therapeutic result. The incidence of radiodermatitis after percutaneous coronary interventions is rising with the increasing number and complexity of these procedures. The main risk factor is a long duration of fluoroscopy using the same incidence. The skin lesions encompass a wide spectrum, ranging from erythema, telangiectasia, atrophy, hyperpigmentation and hypopigmentation to necrosis, chronic ulceration and squamous cell carcinoma. The lesions can appear from 15 days to 10 years after the procedure. To prevent radiation-induced injury, the radiation dose has to be limited and monitored. Also, careful inspection of the skin at the site of exposure is necessary and the radiographic beam has to be restricted to the smallest field size. A good clinical follow-up at regular intervals is important after long and complicated procedures.


Subject(s)
Coronary Angiography/adverse effects , Radiodermatitis/diagnosis , Radiodermatitis/etiology , Aged , Angioplasty, Balloon, Coronary/adverse effects , Cardiac Catheterization/adverse effects , Diagnosis, Differential , Female , Fluoroscopy/adverse effects , Humans , Male , Radiodermatitis/pathology , Radiodermatitis/surgery , Scapula , Skin Transplantation , Stents , Surgical Flaps
16.
Melanoma Res ; 12(5): 479-90, 2002 Oct.
Article in English | MEDLINE | ID: mdl-12394190

ABSTRACT

Staging of melanoma patients by means of whole body functional imaging in a single evaluation session using positron emission tomography (PET) with fluorine-18- labelled deoxy-d-glucose (FDG) as a metabolic tracer has created much interest over the last decade. After enthusiastic pilot studies, more attention has been paid to the false-negative and false-positive results of this technique than to its true therapeutic impact. This study aimed to evaluate (1) the sensitivity and specificity of this technique at a single lesion level compared with conventional screening procedures (CSP) - both of these accompanied by careful clinical examination; and (2) the additional value of the PET scan at the level of the individual patient and its therapeutic impact for different types of melanoma recurrence. A consecutive series of 100 PET scans performed on 84 melanoma patients with regional or distant recurrence according to CSP (89 PET scans) or suspicion of recurrence, i.e. inconclusive CSP (11 PET scans), were retrospectively analysed and compared with the CSP results. At the single lesion level, PET scan and CSP showed a sensitivity of 85 and 81%, a specificity of 90 and 87% and an accuracy of 88 and 84%, respectively. PET provided false-negative results for small skin metastases and brain involvement; false-positive results were associated with unrelated benign or malignant tumours and peripheral soft tissue and bone uptake. PET scan showed an additional value over and above CSP at the individual patient's level by true upstaging in 10 cases, true downstaging in 24 cases and depiction of more lesions within the same stage of disease in 15 cases. The overall therapeutic impact reached 26%: 17 out of 71 (24%) cases with regional recurrence, one out of 18 cases (5.5%) with distant metastasis and eight out of 11 cases (73%) with suspicion of recurrence where CSP remained doubtful. However, in 19 cases comparison between CSP and PET resulted in discordant findings, suggesting upstaging in one area and downstaging at another site within the same patient. In conclusion, PET scan has an additional value in the staging of recurrent melanoma, providing it is accompanied by careful clinical examination and specific brain imaging. However, in the absence of evidence of metastasis or unrelated conditions at the same site on CSP, PET spots may represent false-positive images, which would falsely upgrade a patient to an incurable state, or they may be early true-positive findings, which will become evident during close follow-up.


Subject(s)
Fluorodeoxyglucose F18 , Melanoma/diagnosis , Melanoma/pathology , Tomography, Emission-Computed/methods , Adult , Aged , Aged, 80 and over , False Negative Reactions , False Positive Reactions , Female , Humans , Male , Middle Aged , Neoplasm Metastasis , Neoplasms/diagnosis , Neoplasms/pathology , Radiopharmaceuticals , Recurrence , Sensitivity and Specificity , Skin Neoplasms/diagnosis , Skin Neoplasms/pathology , Time Factors , Tomography, X-Ray Computed
17.
J Invest Dermatol ; 117(5): 1290-5, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11710946

ABSTRACT

Human skin is exposed to an environment that varies in humidity from 100 to 0%, leading to seasonal variations in the condition of the skin. Exposure to a low humidity environment creates an osmotic gradient across the stratum corneum, which is known to modulate cutaneous barrier function. Heat shock proteins protect against stress-induced destabilization of proteins. We investigated whether osmotic shock (sorbitol) induced a heat shock protein response in normal human keratinocytes, and used heat shock as a positive control. Both heat shock and osmotic stress (200 and 300 mM sorbitol) clearly induced heat shock proteins 70 and 27 mRNA levels. The induction of heat shock protein 70 mRNA levels by osmotic stress peaked at 16 h and persisted until 24 h, whereas upregulation of heat shock protein 70 mRNA levels by heat peaked at 2 h and returned to baseline levels by 6 h. Sorbitol also increased heat shock protein 70 levels in a concentration-dependent manner. The kinetics of heat shock protein 27 mRNA induction by osmotic stress and heat were similar with peak induction at 6 h. The mitogen activated protein kinase family of proteins plays an important part in the coordination of gene responses to various stress conditions. We have demonstrated that the p38 mitogen activated protein kinase was strongly activated by 200 mM and 300 mM sorbitol. The specific p38 mitogen activated protein kinase inhibitor PD169316 almost completely blocked heat shock protein 70 mRNA induction by 200 mM and 300 mM sorbitol and completely suppressed heat shock protein 27 mRNA induction with 200 mM sorbitol. PD169316 also counteracted upregulation of heat shock protein 70 levels by sorbitol. These data indicate that keratinocytes respond to osmotic stress by p38 mitogen activated protein kinase regulated induction of heat shock proteins. This molecular pathway may be relevant for the mechanisms regulating the response of human skin to variations in environmental humidity.


Subject(s)
HSP70 Heat-Shock Proteins/metabolism , Heat-Shock Proteins , Keratinocytes/physiology , Mitogen-Activated Protein Kinases/physiology , Neoplasm Proteins/metabolism , Cells, Cultured , Down-Regulation , Enzyme Inhibitors/pharmacology , HSP27 Heat-Shock Proteins , HSP70 Heat-Shock Proteins/genetics , Humans , Imidazoles/pharmacology , Mitogen-Activated Protein Kinases/antagonists & inhibitors , Molecular Chaperones , Neoplasm Proteins/genetics , Osmotic Pressure , RNA, Messenger/metabolism , Reference Values , p38 Mitogen-Activated Protein Kinases
18.
J Photochem Photobiol B ; 63(1-3): 78-83, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11684454

ABSTRACT

p53 is a tumor suppressor gene and mutation of p53 is a frequent event in skin cancer. The wild-type p53 encodes for a 53-kD phosphoprotein that plays a pivotal role in regulating cell growth and cell death. The wt-p53 gene is also called "guardian of the genome", for its role in preventing the accumulation of genetic alterations, observed in cancer cells. The wild-type p53 protein plays a central role in the response of the cell to DNA damage. UV, present in sunlight, is one of the most ubiquitously present DNA damage inducing stress conditions to which skin cells are exposed. The wt-p53 protein accumulates in human skin cells in vitro and in human skin in vivo upon UV irradiation. This upregulation mounts a protective response against permanent DNA damage through transactivation of either cell cycle arrest genes and DNA repair genes or genes that mediate the apoptotic response. The molecular events which regulate the activity of the wt-p53 protein activity are only beginning to be described.


Subject(s)
Skin/radiation effects , Tumor Suppressor Protein p53/physiology , Animals , Humans , Skin/metabolism , Solar Activity , Tumor Suppressor Protein p53/metabolism , Ultraviolet Rays/adverse effects
19.
Melanoma Res ; 10(4): 371-80, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10985672

ABSTRACT

One to two per cent of primary cutaneous melanomas share clinical features with benign melanocytic and non-melanocytic skin lesions, and even at histology recognition of their malignant nature is problematic, mainly due to the lack of an intraepithelial component, their nodular aspect and the monotonous cell population throughout the lesion. These tumours were termed minimal deviation melanomas (MDMs) by Reed et al. and later naevoid melanomas by Schmoeckel et al. The name MDM suggests the concept of a more favourable outcome for these melanomas that do not (yet) show the typical features of fully evolved lesions able to metastasize, although naevoid melanomas seem to behave like 'common' melanomas. In a retrospective analysis of nine cases of MDM collected from our database and followed for a median duration of 112 months, we faced similar clinical and histological pitfalls and observed local recurrence following marginal resection. Wide excision, even of local recurrence, and therapeutic node dissection could nevertheless provide survival comparable at least to that predicted by mathematical models for patients who initially had optimal treatment.


Subject(s)
Melanoma/pathology , Nevus, Epithelioid and Spindle Cell/pathology , Nevus, Pigmented/pathology , Skin Neoplasms/pathology , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Melanoma/classification , Melanoma/therapy , Middle Aged , Neoplasm Recurrence, Local , Nevus, Epithelioid and Spindle Cell/classification , Nevus, Epithelioid and Spindle Cell/therapy , Nevus, Pigmented/classification , Nevus, Pigmented/therapy , Prognosis , Retrospective Studies , Skin Neoplasms/classification , Skin Neoplasms/therapy , Treatment Outcome
20.
J Biol Chem ; 275(28): 21416-21, 2000 Jul 14.
Article in English | MEDLINE | ID: mdl-10748072

ABSTRACT

The mechanisms of UVB-induced apoptosis and the role of p38 mitogen-activated protein kinase (MAPK) were investigated in HaCaT cells. UVB doses that induced apoptosis also produced a sustained activation of p38 MAPK and mitochondrial cytochrome c release, leading to pro-caspase-3 activation. Late into the apoptotic process, UVB also induced a caspase-mediated cleavage of Bid. Caspase inhibitors benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone and benzyloxycarbonyl-Asp-Glu-Val-Asp-fluoromethylketone substantially blocked the UVB-induced apoptosis without preventing the release of mitochondrial cytochrome c and the p38 MAPK activation. The inhibition of p38 MAPK counteracted both apoptosis and cytochrome c release as well as the DEVD-amino-4-methylcoumarin cleavage activity without affecting the processing of pro-caspase-8. These results indicate that UVB induces multiple and independent apoptotic pathways, which culminate in pro-caspase-3 activation, and that the initial cytochrome c release is independent of caspase activity. Importantly, we show that a sustained p38 MAPK activation contributes to the UVB-induced apoptosis by mediating the release of mitochondrial cytochrome c into the cytosol.


Subject(s)
Apoptosis/physiology , Cytochrome c Group/metabolism , Mitogen-Activated Protein Kinases/metabolism , Ultraviolet Rays , Amino Acid Chloromethyl Ketones/pharmacology , Apoptosis/radiation effects , Caspase Inhibitors , Cell Division/drug effects , Cell Division/radiation effects , Cell Line , Cysteine Proteinase Inhibitors/pharmacology , Humans , Imidazoles/pharmacology , Keratinocytes/cytology , Keratinocytes/physiology , Keratinocytes/radiation effects , Kinetics , Mitogen-Activated Protein Kinases/radiation effects , p38 Mitogen-Activated Protein Kinases
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