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1.
J Eur Acad Dermatol Venereol ; 34(1): 17-29, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31805604

RESUMEN

In addition to approved indications in non-melanoma skin cancer in immunocompetent patients, topical photodynamic therapy (PDT) has also been studied for its place in the treatment of, as well as its potential to prevent, superficial skin cancers in immune-suppressed patients, although sustained clearance rates are lower than for immune-competent individuals. PDT using a nanoemulsion of ALA in a daylight or conventional PDT protocol has been approved for use in field cancerization, although evidence of the potential of the treatment to prevent new SCC remained limited. High-quality evidence supports a strong recommendation for the use of topical PDT in photorejuvenation as well as for acne, refractory warts, cutaneous leishmaniasis and in onychomycosis, although these indications currently lack approvals for use and protocols remain to be optimized, with more comparative evidence with established therapies required to establish its place in practice. Adverse events across all indications for PDT can be minimized through the use of modified and low-irradiance regimens, with a low risk of contact allergy to photosensitizer prodrugs, and no other significant documented longer-term risks with no current evidence of cumulative toxicity or photocarcinogenic risk. The literature on the pharmacoeconomics for using PDT is also reviewed, although accurate comparisons are difficult to establish in different healthcare settings, comparing hospital/office-based therapies of PDT and surgery with topical ointments, requiring inclusion of number of visits, real-world efficacy as well as considering the value to be placed on cosmetic outcome and patient preference. This guideline, published over two parts, considers all current approved and emerging indications for the use of topical photodynamic therapy in Dermatology prepared by the PDT subgroup of the European Dermatology Forum guidelines committee. It presents consensual expert recommendations reflecting current published evidence.


Asunto(s)
Fotoquimioterapia , Fármacos Fotosensibilizantes/administración & dosificación , Enfermedades de la Piel/terapia , Administración Tópica , Europa (Continente) , Humanos , Selección de Paciente , Guías de Práctica Clínica como Asunto , Rejuvenecimiento , Enfermedades de la Piel/etiología , Enfermedades de la Piel/patología
2.
J Eur Acad Dermatol Venereol ; 33(12): 2225-2238, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31779042

RESUMEN

Topical photodynamic therapy (PDT) is a widely approved therapy for actinic keratoses, Bowen's disease (squamous cell carcinoma in situ), superficial and certain thin basal cell carcinomas. Recurrence rates when standard treatment protocols are used are typically equivalent to existing therapies, although inferior to surgery for nodular basal cell carcinoma. PDT can be used both as lesional and field therapies and has the potential to delay/reduce the development of new lesions. A protocol using daylight to treat actinic keratoses is widely practised, with conventional PDT using a red light after typically a 3-h period of occlusion employed for other superficial skin cancer indications as well as for actinic keratoses when daylight therapy is not feasible. PDT is a well-tolerated therapy although discomfort associated with conventional protocol may require pain-reduction measures. PDT using daylight is associated with no or minimal pain and preferred by patient. There is an emerging literature on enhancing conventional PDT protocols or combined PDT with another treatment to increase response rates. This guideline, published over two parts, considers all current approved and emerging indications for the use of topical PDT in dermatology, prepared by the PDT subgroup of the European Dermatology Forum guidelines committee. It presents consensual expert recommendations reflecting current published evidence.


Asunto(s)
Enfermedad de Bowen/tratamiento farmacológico , Carcinoma Basocelular/tratamiento farmacológico , Queratosis Actínica/tratamiento farmacológico , Guías de Práctica Clínica como Asunto , Neoplasias Cutáneas/tratamiento farmacológico , Europa (Continente) , Humanos , Fármacos Fotosensibilizantes/uso terapéutico , Sociedades Médicas
4.
J Eur Acad Dermatol Venereol ; 29(9): 1718-23, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25627399

RESUMEN

INTRODUCTION: Daylight-mediated photodynamic therapy has been shown to be an effective therapy for actinic keratoses (AKs) and a simple and tolerable treatment procedure in three randomized Scandinavian studies and two recent Phase III randomized controlled studies in Australia and Europe. OBJECTIVES: To establish consensus recommendations for the use of daylight photodynamic therapy (DL-PDT) using topical methyl aminolaevulinate (MAL) in European patients with AKs. METHODS: The DL-PDT consensus recommendations were developed on behalf of the European Society for Photodynamic Therapy in Dermatology and comprised of 10 dermatologists from different European countries with experience in how to treat AK patients with PDT. Consensus was developed based on literature review and experience of the experts in the treatment of AK using DL-PDT. RESULTS: The recommendations arising from this panel of experts provide general guidance on the use of DL-PDT as a dermatological procedure with specific guidance regarding patient selection, therapeutic indications, when to treat, pre-treatment skin preparation, MAL application and daylight exposure for patients with AK in different countries of Europe. CONCLUSIONS: This consensus recommendation provides a framework for physicians to perform DL-PDT with MAL cream while ensuring efficiency and safety in the treatment of patients with AK in different European countries.


Asunto(s)
Ácido Aminolevulínico/análogos & derivados , Consenso , Queratosis Actínica/tratamiento farmacológico , Fotoquimioterapia/normas , Sociedades Médicas , Administración Tópica , Ácido Aminolevulínico/administración & dosificación , Europa (Continente) , Humanos , Fármacos Fotosensibilizantes/administración & dosificación
6.
J Eur Acad Dermatol Venereol ; 27(6): 672-9, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23181556

RESUMEN

In addition to established indications in non-melanoma skin cancer in immunocompetent patients, photodynamic therapy (PDT) has been studied for the treatment, and possible prevention, of superficial skin cancers in immunosuppressed patients. As a topical photosensitizer can be applied over large areas, PDT is also increasingly used for field cancerization in photodamaged skin, with evidence of potential to delay the development of actinic keratoses and basal cell carcinoma, although direct evidence of prevention of invasive squamous cell carcinoma remains limited. PDT has been studied in patch/plaque-stage cutaneous T-cell lymphoma, with efficacy more likely in unilesional disease. Accumulating evidence supports the use of PDT in acne and several other inflammatory/infective dermatoses including cutaneous leishmaniasis, although protocols are still to be refined. Despite proven efficacy, PDT is not widely used in viral/genital warts, where pain during treatment can be intense. PDT is a therapeutic option for photorejuvenation, with improvement in fine wrinkles, mottled hyperpigmentation, roughness and sallowness reported.


Asunto(s)
Técnicas Cosméticas , Dermatitis/tratamiento farmacológico , Fotoquimioterapia , Enfermedades Cutáneas Infecciosas/tratamiento farmacológico , Neoplasias Cutáneas/tratamiento farmacológico , Humanos , Rejuvenecimiento
7.
J Eur Acad Dermatol Venereol ; 27(5): 536-44, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23181594

RESUMEN

Topical photodynamic therapy (PDT) is a widely used non-invasive treatment for certain non-melanoma skin cancers, permitting treatment of large and multiple lesions with excellent cosmesis. High efficacy is demonstrated for PDT using standardized protocols in non-hyperkeratotic actinic keratoses, Bowen's disease, superficial basal cell carcinomas (BCC) and in certain thin nodular BCC, with superiority of cosmetic outcome over conventional therapies. Recurrence rates following PDT are typically equivalent to existing therapies, although higher than surgery for nodular BCC. PDT is not recommended for invasive squamous cell carcinoma. Treatment is generally well tolerated, but tingling discomfort or pain is common during PDT. New studies identify patients most likely to experience discomfort and permit earlier adoption of pain-minimization strategies. Reduced discomfort has been observed with novel protocols including shorter photosensitizer application times and in daylight PDT for actinic keratoses.


Asunto(s)
Enfermedad de Bowen/tratamiento farmacológico , Carcinoma Basocelular/tratamiento farmacológico , Queratosis Actínica/tratamiento farmacológico , Fotoquimioterapia , Fármacos Fotosensibilizantes/uso terapéutico , Guías de Práctica Clínica como Asunto , Neoplasias Cutáneas/tratamiento farmacológico , Administración Tópica , Europa (Continente) , Fluorescencia , Humanos , Fotoquimioterapia/efectos adversos , Fármacos Fotosensibilizantes/administración & dosificación , Fármacos Fotosensibilizantes/efectos adversos
10.
J Eur Acad Dermatol Venereol ; 26(6): 673-9, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22211665

RESUMEN

Photodynamic therapy (PDT) is an attractive therapy for non-melanoma skin cancers including actinic keratoses (AKs) because it allows treatment of large areas; it has a high response rate and results in an excellent cosmesis. However, conventional PDT for AKs is associated with inconveniently long clinic visits and discomfort during therapy. In this article, we critically review daylight-mediated PDT, which is a simpler and more tolerable treatment procedure for PDT. We review the effective light dose, efficacy and safety, the need for prior application of sunscreen, and potential clinical scope of daylight-PDT. Three randomized controlled studies have shown that daylight-mediated PDT is an effective treatment of thin AKs. Daylight-mediated PDT is nearly pain-free and more convenient for both the clinics and patients. Daylight-mediated PDT is especially suited for patients with large field-cancerized areas, which can easily be exposed to daylight. Further investigations are necessary to determine at which time of the year and in which weather conditions daylight-mediated PDT will be possible in different geographical locations.


Asunto(s)
Queratosis Actínica/tratamiento farmacológico , Fotoquimioterapia , Luz Solar , Eritema/etiología , Humanos , Internacionalidad , Dolor/etiología , Fotoquimioterapia/efectos adversos , Ensayos Clínicos Controlados Aleatorios como Asunto , Protectores Solares/administración & dosificación
11.
J Eur Acad Dermatol Venereol ; 26(9): 1063-6, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22220503

RESUMEN

Field cancerization is a term that describes the presence of genetic abnormalities in a tissue chronically exposed to a carcinogen. These abnormalities are responsible for the presence of multilocular clinical and sub-clinical cancerous lesions that explains the increased risks of multiple cancers in this area. With respect to the skin, this term is used to define the presence of multiple non-melanoma skin cancer, its precursors, actinic keratoses and dysplastic keratinocytes in sun exposed areas. The multiplicity of the lesions and the extent of the area influence the treatment decision. Providing at least equivalent efficacy and tolerability, field directed therapies are therefore often more worthwhile than lesion targeted approaches. Photodynamic therapy (PDT) with its selective sensitization and destruction of diseased tissue is one ideal form of therapy for this indication. In the following paper the use of PDT for the treatment of field cancerized skin is reviewed and recommendations are given for its use.


Asunto(s)
Fotoquimioterapia , Neoplasias Cutáneas/tratamiento farmacológico , Humanos
12.
Br J Dermatol ; 163(3): 607-15, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20426780

RESUMEN

BACKGROUND: Photodynamic therapy (PDT) with methyl aminolaevulinate (MAL) is an effective treatment for multiple actinic keratoses (AKs). Pain, however, is a major side-effect. OBJECTIVES: To compare pain intensity, efficacy, safety and cosmetic outcome of MAL PDT with two different light sources in an investigator-initiated, randomized, double-blind study. METHODS: Eighty patients with multiple AKs grade I-II were assigned to two groups: group 1, MAL PDT with visible light and water-filtered infrared A (VIS+wIRA); group 2, MAL PDT with light from light-emitting diodes (LEDs), with a further division into two subgroups: A, no spray cooling; B, spray cooling on demand. MAL was applied 3 h before light treatment. Pain was assessed before, during and after PDT. Efficacy, side-effects, cosmetic outcome and patient satisfaction were documented after 2 weeks and 3, 6 and 12 months. Where necessary, treatment was repeated after 3 months. RESULTS: Seventy-six of the 80 patients receiving MAL PDT completed the study. Patient assessment showed high efficacy, very good cosmetic outcome and high patient satisfaction. The efficacy of treatment was better in the group of patients without spray cooling (P=0·00022 at 3 months, P=0·0068 at 6 months) and showed no significant differences between VIS+wIRA and LED. VIS+wIRA was significantly less painful than LED: the median of maximum pain was lower in the VIS+wIRA group than in the LED group for PDT without spray cooling. Pain duration and severity assessed retrospectively were less with VIS+wIRA than with LED, irrespective of cooling. CONCLUSIONS: All treatments showed high efficacy with good cosmetic outcome and high patient satisfaction. Efficacy of treatment was better without spray cooling. VIS+wIRA PDT was less painful than LED PDT for PDT without spray cooling.


Asunto(s)
Rayos Infrarrojos/uso terapéutico , Queratosis Actínica/terapia , Dolor/etiología , Fotoquimioterapia/métodos , Anciano , Anciano de 80 o más Años , Ácido Aminolevulínico/efectos adversos , Ácido Aminolevulínico/análogos & derivados , Ácido Aminolevulínico/uso terapéutico , Método Doble Ciego , Femenino , Filtración/métodos , Humanos , Láseres de Semiconductores/efectos adversos , Láseres de Semiconductores/uso terapéutico , Masculino , Persona de Mediana Edad , Dolor/prevención & control , Dimensión del Dolor , Satisfacción del Paciente , Fotoquimioterapia/efectos adversos , Fármacos Fotosensibilizantes/efectos adversos , Fármacos Fotosensibilizantes/uso terapéutico , Agua
13.
Cell Mol Life Sci ; 66(4): 681-96, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19137261

RESUMEN

hShroom1 (hShrm1) is a member of the Apx/Shroom (Shrm) protein family and was identified from a yeast two-hybrid screen as a protein that interacts with the cytoplasmic domain of melanoma cell adhesion molecule (MCAM). The characteristic signature of the Shrm family is the presence of a unique domain, ASD2 (Apx/Shroom domain 2). mRNA analysis suggests that hShrm1 is expressed in brain, heart, skeletal muscle, colon, small intestine, kidney, placenta and lung tissue, as well a variety of melanoma and other cell lines. Co-immunoprecipitation and bioluminescence resonance energy transfer (BRET) experiments indicate that hShrm1 and MCAM interact in vivo and by immunofluorescence microscopy some co-localization of these proteins is observed. hShrm1 partly co-localises with beta-actin and is found in the Triton X-100 insoluble fraction of melanoma cell extracts. We propose that hShrm1 is involved in linking MCAM to the cytoskeleton.


Asunto(s)
Actinas/metabolismo , Citoesqueleto/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas de Microfilamentos/metabolismo , Isoformas de Proteínas/metabolismo , Empalme Alternativo , Secuencia de Aminoácidos , Animales , Antígeno CD146/genética , Antígeno CD146/metabolismo , Línea Celular , Humanos , Melanoma/genética , Melanoma/metabolismo , Proteínas de la Membrana/genética , Proteínas de Microfilamentos/genética , Datos de Secuencia Molecular , Isoformas de Proteínas/genética , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Técnicas del Sistema de Dos Híbridos
15.
Allergy ; 64(8): 1157-65, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19220218

RESUMEN

BACKGROUND: In 16 patients with revised metal-on-metal arthroplasty and peri-implant lymphocytic inflammation, we verified the role of metal hypersensitivity by patch testing (PT) and lymphocyte transformation test (LTT). METHODS: In the 16 patients with lymphocyte dominated periprosthetic inflammation, allergy history was obtained by a questionnaire, specific serum IgE to aeroallergens was measured to assess atopy, PT to standard and metal series was performed and metal sensitivity was further assessed by LTT using blood mononuclear cells. RESULTS: Revision surgery was performed because of pain (8/16), osteolysis (4/16), dislocation (3/16) and loosening of the stem (1/16). Histological examination showed perivascular infiltrates of T lymphocytes, high endothelial venules, fibrin exudation and accumulation of macrophages with drop-like inclusions. Five patients had a history of cutaneous metal allergy and atopy was found in 25% of the patients. In 13/16 patients (81%), systemic metal sensitivity was found based on PT and/or LTT. Patch test reactions were seen in 11/16 patients (69%; partly multiple reactions/patient): 7/16 to Cobalt (Co), 7/16 to Chromium (Cr), 4/16 to Nickel (Ni), and one each to Molybdenum (Mo) and Manganese (Mn). Ten of 16 patients (62%) showed enhanced LTT reactivity to metals: 7/16 to Ni, 7/16 to Co, 5/16 to Cr, 5/16 to Mo and 4/16 to Mn. CONCLUSIONS: The lymphocyte dominated peri-implant inflammation may well reflect an allergic hyper-reactivity in these patients, given the high rate of concomitantly found metal allergy. Despite the overall incidence of metal implant allergy being low, allergic reactions should be included as differential diagnosis in failed metal-on-metal arthroplasty.


Asunto(s)
Alérgenos/inmunología , Artroplastia de Reemplazo de Cadera/efectos adversos , Prótesis de Cadera/efectos adversos , Hipersensibilidad/inmunología , Metales/inmunología , Falla de Prótesis , Linfocitos T/inmunología , Anciano , Anciano de 80 o más Años , Europa (Continente)/epidemiología , Femenino , Humanos , Hipersensibilidad/diagnóstico , Hipersensibilidad/epidemiología , Inmunoensayo , Incidencia , Inflamación/diagnóstico , Inflamación/epidemiología , Inflamación/inmunología , Masculino , Persona de Mediana Edad , Pruebas del Parche , Reoperación
17.
J Eur Acad Dermatol Venereol ; 23(5): 550-5, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19415804

RESUMEN

BACKGROUND: Photodynamic therapy (PDT) using methyl aminolevulinate (MAL) is an effective first-line treatment for actinic keratoses. A reduced incubation period may have practical advantages. OBJECTIVE: This study aims to evaluate the effect of incubation time (1 vs. 3 h), MAL concentration (160 mg/g vs. 80 mg/g) and lesion preparation in the setting of MAL-PDT for treatment of actinic keratosis (AK). DESIGN: Open, randomized, parallel-group multicentre study. SETTING: Outpatient dermatology clinics. SUBJECTS: One hundred and twelve patients with 384 previously untreated AK. Most lesions (87%) were located on the face and scalp and were thin (55%) or moderately thick (34%). METHODS: Lesions were debrided, and MAL cream (160 mg/g or 80 mg/g) was applied before illumination with red light (570-670 nm; light dose, 75 J/cm2). Patients were followed up at 2 and 3 months. Sixty patients (54%) were re-treated and assessed at 6 months. MAIN OUTCOME: Complete lesion response rates 3 and 12 months after last treatment. RESULTS: For lesions on the face/scalp, lesion complete response rates were 78% for thin AK and 74% for moderately thick AK lesions after 1 h vs. 96% and 87% after 3 h incubation with MAL 160 mg/g. Lesion recurrence rates at 12 months after two treatments were similar [19% (3 of 16) with 1 h vs. 17% (3 of 18) with 3 h 160 mg/kg MAL-PDT] and lower than for 80 mg/g MAL-PDT (44-45%). CONCLUSION: MAL-PDT using a 1-h incubation may be sufficient for successful treatment of selected AK lesions.


Asunto(s)
Ácido Aminolevulínico/análogos & derivados , Queratosis Actínica/tratamiento farmacológico , Fotoquimioterapia , Fármacos Fotosensibilizantes/uso terapéutico , Adulto , Anciano , Anciano de 80 o más Años , Ácido Aminolevulínico/administración & dosificación , Ácido Aminolevulínico/efectos adversos , Ácido Aminolevulínico/uso terapéutico , Cosméticos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fármacos Fotosensibilizantes/administración & dosificación , Fármacos Fotosensibilizantes/efectos adversos , Recurrencia , Resultado del Tratamiento
18.
J Eur Acad Dermatol Venereol ; 22(1): 7-10, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18181967

RESUMEN

BACKGROUND: Non-healing leg ulcers represent a treatment problem. OBJECTIVE: Investigate grafting of autologous suction blister roofs as treatment. METHODS: Twenty-nine chronic, non-healing leg ulcers of various aetiologies in 18 inpatients were treated by autologous epidermal grafting using the roofs of suction blisters. RESULTS: 55% of ulcers completely healed 2 to 6 weeks after grafting. A 50-90% reduction in size was documented in 34% and no change was observed in 11% of ulcers. Twelve weeks after grafting, 89% of ulcers were healed completely. In most ulcers, we observed a stimulation of reepithelialization from the wound edge ('edge effect') and an accelerated formation of healthy granulation tissue. During a follow-up period of 12 months, 90% of the ulcers remained healed. CONCLUSION: Grafting of autologous suction blister roofs is an effective treatment option for non-healing leg ulcers. The advantages of the method are its lack of pain, low costs and immediate availability.


Asunto(s)
Epidermis/trasplante , Úlcera de la Pierna/cirugía , Trasplante de Piel/métodos , Anciano , Anciano de 80 o más Años , Vesícula , Enfermedad Crónica , Epidermis/patología , Epidermis/fisiología , Femenino , Tejido de Granulación/patología , Tejido de Granulación/fisiología , Humanos , Úlcera de la Pierna/patología , Úlcera de la Pierna/fisiopatología , Masculino , Persona de Mediana Edad , Piel/patología , Piel/fisiopatología , Succión , Trasplante Autólogo , Cicatrización de Heridas/fisiología
19.
Eur J Cell Biol ; 69(3): 245-58, 1996 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8900489

RESUMEN

Palmar and plantar epidermis is characterized by specific features such as the development of a striking lucidum, a very thick stratum corneum, prominent rete ridges and the unique expression of keratin K9. Using organotypic cocultures of keratinocytes and fibroblasts, we investigated to which extent the specific phenotype of palmar keratinocytes is maintained in vitro and under systemic host influences after transplantation onto nude mice. In vitro, palmar keratinocytes developed a thick epithelium with a prominent, although parakeratotic stratum corneum showing no significant differences in proliferation and differentiation in coculture with either palmar or nonpalmoplantar fibroblasts. All differentiation markers including keratohyaline and membrane coating granules as well as keratin K9 were also found, but at reduced levels and with slightly altered localization. In transplants, substantial normalization towards the palmar phenotype occurred. In 3-week-old grafts, a homeostatic state was reached, as illustrated by a constant thickness of the stratum Malpighii, presence of keratin K10 throughout the entire suprabasal compartment, increased numbers of K9- and filaggrin-positive cells, and reduction of keratins K16 and K17. At the ultrastructural level, numerous membrane coating granules and an enlargement of keratohyaline granules were seen accordingly, and immunofluorescence showed intense continuous lining of the dermo-epidermal junction by laminin, type IV collagen and integrin alpha 6. The high percentage of bromodesoxyuridine-positive cells, mainly in the basal compartment, underlined the hyproproliferative state, comparable to palmoplantar epidermis. In conclusion, (i) palmar keratinocytes can preserve the potential to express their specific phenotype upon transfer to culture conditions, and (ii) this intrinsic property is not significantly modulated by the type of cocultured fibroblasts. This suggests that fibroblasts act primarily by sustaining keratinocyte proliferation which is permissive for the fully differentiated phenotype.


Asunto(s)
Queratinocitos/metabolismo , Queratinas/metabolismo , Piel/metabolismo , Adolescente , Adulto , Anciano , Animales , Diferenciación Celular , Trasplante de Células , Células Cultivadas , Niño , Proteínas Filagrina , Técnica del Anticuerpo Fluorescente Indirecta , Humanos , Queratinocitos/citología , Masculino , Ratones , Ratones Desnudos , Persona de Mediana Edad , Piel/citología
20.
J Invest Dermatol ; 115(4): 668-73, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10998141

RESUMEN

The melanoma cell adhesion molecule is a membrane glycoprotein whose expression is associated with tumor progression and the development of metastatic potential. The mechanisms for upregulation of the melanoma cell adhesion molecule during melanoma progression are still poorly understood. In this study, we show further evidence that melanoma cell adhesion molecule expression is tightly regulated at the transcriptional level. Using a combination of chloramphenicol acetyl transferase reporter assays and DNA mobility shift experiments, we investigated the role played by three putative melanoma cell adhesion molecule regulatory elements, namely the initiator sequence, the SCA element, and the ASp element. The SCA and the ASp boxes can potentially interact with the transcription factors Sp1 and AP-2. Sp1 binding to both sites was confirmed, but only the SCA sequence could form a complex with AP-2. AP-2-driven downregulation of the melanoma cell adhesion molecule promoter, however, did not depend only on a functional SCA element. The pyrimidine-rich CTCACTTG initiator, which overlaps the RNA start site, was essential for promoter function and was shown to interact with proteins related to basic helix-loop-helix transcription factors. Binding in nonmetastatic melanoma cells was induced by cAMP. In metastatic cells, however, binding was constitutive, but could be markedly decreased upon treatment with phorbol esters. As melanoma cell adhesion molecule expression is modulated by cAMP and phorbol ester signaling, these results suggest that the initiator is the central element that mediates cAMP and phorbol ester sensitivity and initiates melanoma cell adhesion molecule overexpression in melanomas.


Asunto(s)
Antígenos CD , Antígenos de Superficie/genética , Codón Iniciador/fisiología , Glicoproteínas de Membrana , Moléculas de Adhesión de Célula Nerviosa , Animales , Antígeno CD146 , Proteínas de Unión al ADN/fisiología , Regulación hacia Abajo , Regulación de la Expresión Génica , Ratones , Regiones Promotoras Genéticas/fisiología , Neoplasias Cutáneas/química , Neoplasias Cutáneas/genética , Factores de Transcripción/fisiología , Transcripción Genética/efectos de los fármacos
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