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1.
J Cutan Pathol ; 51(1): 11-14, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37150806

RESUMO

Superficial CD34 fibroblastic tumors (SCD34FT) and PRDM10-rearranged tumors (PRTs) are mesenchymal tumors that have recently received increased scientific attention due to their irrefutable similarities yet debatable relationship. A 74-year-old male presented to the dermatology clinic with a violaceous, well-defined nodule on the left medial knee of 2-year duration. Shave biopsy demonstrated spindle cells arranged in a vaguely storiform pattern forming fascicles. Immunohistochemical stains were positive for vimentin, CD68, CD10, and CD34 diffusely. ERG, S-100, HMB45, and SOX-10 were negative. Molecular studies identified a mediator complex subunit 12 (MED12)-PR/SET Domain 10 (PRDM10) gene fusion thus favoring confirming the diagnosis of a PRT. Our patient underwent wide local excision with negative margins and had no complications. This case aims to provide context for considering SCD34FT and PRT as intersecting entities and to discuss a diagnostic approach when encountering these tumors.


Assuntos
Neoplasias de Tecido Fibroso , Neoplasias de Tecidos Moles , Masculino , Humanos , Idoso , Neoplasias de Tecidos Moles/diagnóstico , Neoplasias de Tecidos Moles/genética , Neoplasias de Tecidos Moles/patologia , Fatores de Transcrição/genética , Antígenos CD34 , Biópsia , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/análise , Proteínas de Ligação a DNA/genética
3.
J Am Acad Dermatol ; 85(4): 945-955, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34111497

RESUMO

BACKGROUND: Actinic keratoses (AK) are rough scaly patches that arise on chronically ultraviolet-exposed skin and can progress to keratinocyte carcinoma. Treatment options for AK include topical medications, photodynamic therapy, cryosurgery, and laser ablation. OBJECTIVE: This executive summary provides a synopsis of the 18 evidence-based recommendations for the treatment of AK detailed in the Guidelines of Care for the Management of Actinic Keratosis. METHODS: A multidisciplinary workgroup conducted a systematic review to address 5 clinical questions on the management of AKs and applied the Grading of Recommendations Assessment, Development and Evaluation approach for assessing the certainty of the evidence and formulating and grading clinical recommendations. Graded recommendations were voted on to achieve consensus. RESULTS: Analysis of the evidence resulted in 18 recommendations, suggesting there are several effective treatments available for AK. LIMITATIONS: The analysis informing the recommendations was based on the best available evidence at the time it was conducted. The results of future studies may necessitate a revision of current recommendations. CONCLUSIONS: Strong recommendations are presented for using ultraviolet protection, topical imiquimod, topical 5-fluorouracil, and cryosurgery. Conditional recommendations are presented for the use of photodynamic therapy and diclofenac for the treatment of AK, both individually and as part of combination therapy regimens.


Assuntos
Ceratose Actínica , Criocirurgia , Fluoruracila/uso terapêutico , Humanos , Imiquimode/uso terapêutico , Ceratose Actínica/tratamento farmacológico , Fotoquimioterapia , Guias de Prática Clínica como Assunto
4.
J Am Acad Dermatol ; 85(4): e209-e233, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33820677

RESUMO

BACKGROUND: Actinic keratoses (AK) are rough scaly patches that arise on chronically ultraviolet-exposed skin and can progress to keratinocyte carcinoma. OBJECTIVE: This analysis examined the literature related to the management of AK to provide evidence-based recommendations for treatment. Grading, histologic classification, natural history, risk of progression, and dermatologic surveillance of AKs are also discussed. METHODS: A multidisciplinary Work Group conducted a systematic review to address 5 clinical questions on the management of AKs and applied the Grading of Recommendations, Assessment, Development, and Evaluation approach for assessing the certainty of the evidence and formulating and grading clinical recommendations. Graded recommendations were voted on to achieve consensus. RESULTS: Analysis of the evidence resulted in 18 recommendations. LIMITATIONS: This analysis is based on the best available evidence at the time it was conducted. The pragmatic decision to limit the literature review to English language randomized trials may have excluded data published in other languages or limited identification of relevant long-term follow-up data. CONCLUSIONS: Strong recommendations are made for using ultraviolet protection, topical imiquimod, topical 5-fluorouracil, and cryosurgery. Conditional recommendations are made for the use of photodynamic therapy and diclofenac for the treatment of AK, both individually and as part of combination therapy regimens.


Assuntos
Ceratose Actínica , Fotoquimioterapia , Diclofenaco/uso terapêutico , Fluoruracila/uso terapêutico , Humanos , Imiquimode/uso terapêutico , Ceratose Actínica/tratamento farmacológico
5.
6.
J Invest Dermatol ; 139(5): 1127-1134, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30500343

RESUMO

Tools that help reduce the number of surgical biopsies performed on benign lesions have the potential to improve patient care. The pigmented lesion assay (PLA) is a noninvasive tool validated against histopathology that helps rule out melanoma and the need for surgical biopsies of atypical pigmented skin lesions. Genetic information is collected using adhesive patches and the expression of two genes, LINC and PRAME, is measured. By using genetic material collected noninvasively and to further validate the PLA, somatic hotspot mutations in genes known to be drivers of early melanoma development (BRAF other than V600E, NRAS, and the TERT promoter) can also be identified. The frequency of these hotspot mutations in samples of early melanoma was 77%, which is higher than the 14% found in nonmelanoma samples (P < 0.0001). TERT promoter mutations were the most prevalent mutation type in PLA-positive melanomas; 82% of PLA-negative lesions had no mutations, and 97% of histopathologically confirmed melanomas were PLA and/or mutation positive (cohort 1, n = 103). Mutation frequencies were similar in prospectively collected real-world PLA samples (cohort 2, n = 519), in which 88% of PLA-negative samples had no mutations. Combining gene expression and mutation analyses enhances the ability to noninvasively detect early cutaneous melanoma.


Assuntos
Antígenos de Neoplasias/genética , Regulação Neoplásica da Expressão Gênica , Melanoma/genética , RNA Longo não Codificante/genética , Neoplasias Cutâneas/genética , Transcriptoma/genética , Adulto , Idoso , Biópsia por Agulha , Estudos de Coortes , Análise Mutacional de DNA , Feminino , Perfilação da Expressão Gênica , Humanos , Imuno-Histoquímica , Masculino , Melanoma/patologia , Pessoa de Meia-Idade , Regiões Promotoras Genéticas , Sensibilidade e Especificidade , Neoplasias Cutâneas/patologia
7.
Front Neurosci ; 11: 737, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29379409

RESUMO

The discovery of biomarkers for Parkinson's disease (PD) is challenging due to the heterogeneous nature of this disorder, and a poor correlation between the underlying pathology and the clinically expressed phenotype. An ideal biomarker would inform on PD-relevant pathological changes via an easily assayed biological characteristic, which reliably tracks clinical symptoms. Human dermal (skin) fibroblasts are accessible peripheral cells that constitute a patient-specific system, which potentially recapitulates the PD chronological and epigenetic aging history. Here, we compared primary skin fibroblasts obtained from individuals diagnosed with late-onset sporadic PD, and healthy age-matched controls. These fibroblasts were studied from fundamental viewpoints of growth and morphology, as well as redox, mitochondrial, and autophagic function. It was observed that fibroblasts from PD subjects had higher growth rates, and appeared distinctly different in terms of morphology and spatial organization in culture, compared to control cells. It was also found that the PD fibroblasts exhibited significantly compromised mitochondrial structure and function when assessed via morphological and oxidative phosphorylation assays. Additionally, a striking increase in baseline macroautophagy levels was seen in cells from PD subjects. Exposure of the skin fibroblasts to physiologically relevant stress, specifically ultraviolet irradiation (UVA), further exaggerated the autophagic dysfunction in the PD cells. Moreover, the PD fibroblasts accumulated higher levels of reactive oxygen species (ROS) coupled with lower cell viability upon UVA treatment. In essence, these studies highlight primary skin fibroblasts as a patient-relevant model that captures fundamental PD molecular mechanisms, and supports their potential utility to develop diagnostic and prognostic biomarkers for the disease.

8.
Arch Dermatol Res ; 308(4): 239-48, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26873374

RESUMO

Mitochondria are the major source of reactive oxygen species (ROS) in fibroblasts which are thought to be crucial regulators of wound healing with a potential to affect the expression of nuclear genes involved in this process. ROS generated by mitochondria are involved in all stages of tissue repair process but the regulation of ROS-generating system in fibroblasts still remains poorly understood. The purpose of this study was to better understand molecular mechanisms of how the regulation of ROS levels generated by mitochondria may influence the process of wound repair. Cybrid model system of mtDNA variations was used to study the functional consequences of altered ROS levels on wound healing responses in a uniform nuclear background of cultured ρ(0) fibroblasts. Mitochondrial ROS in cybrids were modulated by antioxidants that quench ROS to examine their ability to close the wound. Real-time PCR arrays were used to investigate whether ROS generated by specific mtDNA variants have the ability to alter expression of some key nuclear-encoded genes central to the wound healing response and oxidative stress. Our data suggest levels of mitochondrial ROS affect expression of some nuclear encoded genes central to wound healing response and oxidative stress and modulation of mitochondrial ROS by antioxidants positively affects in vitro process of wound closure. Thus, regulation of mitochondrial ROS-generating system in fibroblasts can be used as effective natural redox-based strategy to help treat non-healing wounds.


Assuntos
Fibroblastos/metabolismo , Mitocôndrias/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Fenômenos Fisiológicos da Pele , Cicatrização/fisiologia , Animais , Antioxidantes/metabolismo , Proliferação de Células , DNA Mitocondrial/genética , Camundongos , Camundongos Endogâmicos BALB C , Pele/citologia , Pele/lesões , Pele/metabolismo
10.
Semin Cutan Med Surg ; 33(4 Suppl): S76-80, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25268601

RESUMO

Actinic keratosis (AK) is a common premalignant skin lesion that is frequently treated by cryosurgery. Basal cell carcinoma is the most common malignancy of man, and early-stage lesions are usually cured via surgery. Advanced basal cell carcinoma may require more extensive surgery resulting in deformity, and many advanced lesions cannot be treated surgically. Several recent developments have improved therapeutic options for both conditions. Cryosurgery is still a mainstay of treatment for AK, but the introduction of effective topical agents, imiquimod cream and ingenol mebutate, has provided alternatives to cryosurgery. For advanced basal cell carcinoma, the small-molecule inhibitor vismodegib has proven to be an effective therapy for lesions that are not amenable to surgery and has demonstrated ability to achieve dramatic improvement in advanced, potentially disfiguring cancer.


Assuntos
Ceratose Actínica/tratamento farmacológico , Neoplasias Cutâneas/tratamento farmacológico , Aminoquinolinas/uso terapêutico , Anilidas/uso terapêutico , Antineoplásicos/uso terapêutico , Carcinoma Basocelular/tratamento farmacológico , Criocirurgia , Diterpenos/uso terapêutico , Humanos , Imiquimode , Ceratose Actínica/genética , Ceratose Actínica/cirurgia , Mutação , Receptores Patched , Piridinas/uso terapêutico , Receptores de Superfície Celular/genética , Resultado do Tratamento
11.
Mutat Res ; 769: 49-58, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25177208

RESUMO

mtDNA mutations are common in human cancers and are thought to contribute to the process of neoplasia. We examined the role of mtDNA mutations in skin cancer by generating fibroblast cybrids harboring a mutation in the gene encoding the mitochondrial tRNA for arginine. This somatic mutation (9821insA) was previously reported in UV-induced hyperkeratotic skin tumors in hairless mice and confers specific tumorigenic phenotypes to mutant cybrids. Microarray analysis revealed and RT-PCR along with Western blot analysis confirmed the up-regulation of CCL20 and its receptor CCR6 in mtBALB haplotype containing the mt-Tr 9821insA allele compared to wild type mtB6 haplotype. Based on reported role of CCL20 in cancer progression we examined whether the hyper-proliferation and enhanced motility of mtBALB haplotype would be associated with CCL20 levels. Treatment of both genotypes with recombinant CCL20 (rmCCL20) resulted in enhanced growth and motility of mtB6 cybrids. Furthermore, the acquired somatic alteration increased the in vivo tumor growth of mtBALB cybrids through the up-regulation of CCL20 since neutralizing antibody significantly decreased in vivo tumor growth of these cells; and tumors from anti-CCL20 treated mice injected with mtBALB cybrids showed significantly decreased CCL20 levels. When rmCCL20 or mtBALB cybrids were used as chemotactic stimuli, mtB6 cybrids showed increased motility while anti-CCL20 antibody decreased the migration and in vivo tumor growth of mtBALB cybrids. Moreover, the inhibitors of MAPK signaling and NF-κB activation inhibited CCL20 expression in mtBALB cybrids and decreased their migratory capabilities. Thus, acquired mtDNA mutations may promote tumorigenic phenotypes through up-regulation of chemokine CCL20.


Assuntos
Carcinogênese/genética , Quimiocina CCL20/genética , DNA Mitocondrial/genética , Células Híbridas/metabolismo , Mutação , Animais , Sequência de Bases , Carcinogênese/metabolismo , Células Cultivadas , Quimiocina CCL20/metabolismo , Regulação Neoplásica da Expressão Gênica , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Fenótipo , Regulação para Cima/genética
13.
Dermatol Online J ; 20(2)2014 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-24612577

RESUMO

Cutaneous metastasis is an uncommon but well recognized phenomenon occurring as a result of internal malignancy. Cancers most often associated with cutaneous metastasis are melanoma and primary malignancies of the breast and head and neck. Cutaneous metastatic prostate cancer is rare, representing only 1% of cases. Herein we report a case of advanced prostate cancer with multiple cutaneous metastases and briefly review the literature highlighting the clinical and histopathological features as well as a management approach to the patient with metastatic prostate cancer involving the skin.


Assuntos
Adenocarcinoma/secundário , Neoplasias de Cabeça e Pescoço/secundário , Neoplasias da Próstata/patologia , Neoplasias Cutâneas/secundário , Adenocarcinoma/patologia , Idoso de 80 Anos ou mais , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Masculino , Neoplasias Cutâneas/patologia
15.
Exp Cell Res ; 319(5): 750-60, 2013 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-23220213

RESUMO

The CyP40 protein encoded by PPID gene is a member of the peptidyl-prolyl cis-trans isomerase (PPIase) family. PPIases catalyze the cis-trans isomerization of proline imidic peptide bonds in oligopeptides and accelerate the folding of proteins. The CyP40 protein has been shown to possess PPIase activity and, similar to other family members, can bind to the immunosuppressant drug cyclosporin A (CsA). In this study, we created keratinocyte cell lines with CyP40 being stably knocked down using viral particles containing shRNA for CyP40 which knocked down the expression level of CyP40 transcripts by 90-99%. The proliferation rates of the cell lines with silenced CyP40 were decreased compared to the control cells. After UVA irradiation, the rate of apoptosis was found to be significantly lower in CyP40 silenced cell lines than it was in control cells. Moreover, mitochondrial membrane potential (MMP) was found to be less dissipated and mitochondrial permeability transition pore (MPTP) less active in cells with knocked down CyP40 than in control cells after UVA irradiation. Also, less mitochondrial superoxide was detected in the cells with silenced CyP40 compared to control cells after UVA exposure. Moreover, silencing of CyP40 partially modulates expression of key genes involved in mitochondrial pore formation including CyPD, ANTs and VDAC family members. The ability of CyP40 to regulate UV induced apoptosis implicates this protein as a potential target for therapy in cancer cells.


Assuntos
Apoptose/efeitos da radiação , Ciclofilinas/metabolismo , Queratinócitos/patologia , Mitocôndrias/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Raios Ultravioleta/efeitos adversos , Western Blotting , Proliferação de Células/efeitos da radiação , Células Cultivadas , Ciclofilinas/antagonistas & inibidores , Ciclofilinas/genética , Citometria de Fluxo , Humanos , Queratinócitos/metabolismo , Queratinócitos/efeitos da radiação , Mitocôndrias/efeitos da radiação , Proteínas de Transporte da Membrana Mitocondrial/efeitos da radiação , Poro de Transição de Permeabilidade Mitocondrial , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa
16.
J Photochem Photobiol B ; 113: 42-50, 2012 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-22673012

RESUMO

Resveratrol (3,5,4'-trihydroxy-trans-stilbene), a polyphenol compound, is derived from natural products such as the skin of red grapes, blueberries and cranberries. Resveratrol not only exhibits antioxidant, cardioprotection, and anti-aging properties, but can also inhibit cancer cell growth and induce apoptosis. It has been shown that resveratrol inhibits the activation of Nf-κB and subsequently down regulates the expression of Nf-κB regulated genes such as interleukin-2 and Bcl-2, leading to cell cycle arrest and increased apoptosis in multiple myeloma cells. In the skin, resveratrol has been reported to sensitize keratinocytes to UVA induced apoptosis. However, the effect of resveratrol on opening of the mitochondrial permeability transition pore has not been previously examined. Our data show that UVA (14 J/cm(2)) along with resveratrol causes massive oxidative stress in mitochondria. As a consequence of oxidative stress, the mitochondrial membrane potential decreases which results in opening of the mitochondrial pores ultimately leading to apoptosis in human keratinocytes. These results may have clinical implications for development of future chemotherapeutic treatment for tumors of the skin.


Assuntos
Apoptose/efeitos da radiação , Queratinócitos/efeitos da radiação , Mitocôndrias/efeitos da radiação , Proteínas de Transporte da Membrana Mitocondrial/efeitos da radiação , Estresse Oxidativo/efeitos da radiação , Estilbenos/farmacologia , Raios Ultravioleta , Apoptose/efeitos dos fármacos , Células HEK293 , Humanos , Queratinócitos/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Proteínas de Transporte da Membrana Mitocondrial/efeitos dos fármacos , Poro de Transição de Permeabilidade Mitocondrial , Estresse Oxidativo/efeitos dos fármacos , Resveratrol
17.
Exp Cell Res ; 318(17): 2215-25, 2012 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-22705584

RESUMO

We previously reported the presence of a mtDNA mutation hotspot in UV-induced premalignant and malignant skin tumors in hairless mice. We have modeled this change (9821insA) in murine cybrid cells and demonstrated that this alteration in mtDNA associated with mtBALB haplotype can alter the biochemical characteristics of cybrids and subsequently can contribute to significant changes in their behavioral capabilities. This study shows that changes in mtDNA can produce differences in expression levels of specific nuclear-encoded genes, which are capable of triggering the phenotypes such as seen in malignant cells. From a potential list of differentially expressed genes discovered by microarray analysis, we selected MMP-9 and Col1a1 for further studies. Real-time PCR confirmed up-regulation of MMP-9 and down-regulation of Col1a1 in cybrids harboring the mtDNA associated with the skin tumors. These cybrids also showed significantly increased migration and invasion abilities compared to wild type. The non-specific MMP inhibitor, GM6001, was able to inhibit migratory and invasive abilities of the 9821insA cybrids confirming a critical role of MMPs in cellular motility. Nuclear factor-κB (NF-κB) is a key transcription factor for production of MMPs. An inhibitor of NF-κB activation, Bay 11-7082, was able to inhibit the expression of MMP-9 and ultimately decrease migration and invasion of mutant cybrids containing 9821insA. These studies confirm a role of NF-κB in the regulation of MMP-9 expression and through this regulation modulates the migratory and invasive capabilities of cybrids with mutant mtDNA. Enhanced migration and invasion abilities caused by up-regulated MMP-9 may contribute to the tumorigenic phenotypic characteristics of mutant cybrids.


Assuntos
Núcleo Celular/genética , Transformação Celular Neoplásica/patologia , DNA Mitocondrial/genética , Metaloproteinase 9 da Matriz/metabolismo , Mitocôndrias/patologia , NF-kappa B/metabolismo , Neoplasias Cutâneas/patologia , Animais , Apoptose/efeitos dos fármacos , Movimento Celular , Núcleo Celular/metabolismo , Transformação Celular Neoplásica/genética , Células Cultivadas , Dipeptídeos/farmacologia , Metaloproteinase 9 da Matriz/genética , Inibidores de Metaloproteinases de Matriz , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Mutação/genética , NF-kappa B/antagonistas & inibidores , NF-kappa B/genética , Nitrilas/farmacologia , Fenótipo , Inibidores de Proteases/farmacologia , Reação em Cadeia da Polimerase em Tempo Real , Neoplasias Cutâneas/genética , Sulfonas/farmacologia
18.
J Invest Dermatol ; 132(2): 421-8, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22011905

RESUMO

There is increasing awareness of the role of mtDNA alterations in the development of cancer, as mtDNA point mutations are found at high frequency in a variety of human tumors. To determine the biological effects of mtDNA mutations in UV-induced skin tumors, hairless mice were irradiated to produce tumors, and the tumor mtDNAs were screened for single-nucleotide changes using temperature gradient capillary electrophoresis (TGCE), followed by direct sequencing. A mutation hot spot (9821insA) in the mitochondrially encoded tRNA arginine (mt-Tr) locus (tRNA(Arg)) was discovered in approximately one-third of premalignant and malignant skin tumors. To determine the functional relevance of this particular mutation in vitro, cybrid cell lines containing different mt-Tr (tRNA(Arg)) alleles were generated. The resulting cybrid cell lines contained the same nuclear genotype and differed only in their mtDNAs. The biochemical analysis of the cybrids revealed that the mutant haplotype is associated with diminished levels of complex I protein (CI), resulting in lower levels of baseline oxygen consumption and lower cellular adenosine triphosphate (ATP) production. We hypothesize that this specific mtDNA mutation alters cellular biochemistry, supporting the development of keratinocyte neoplasia.


Assuntos
DNA Mitocondrial/genética , Mutação , Neoplasias Induzidas por Radiação/genética , Neoplasias Cutâneas/genética , Trifosfato de Adenosina/biossíntese , Animais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Neoplasias Induzidas por Radiação/metabolismo , Consumo de Oxigênio , RNA de Transferência de Arginina/química , RNA de Transferência de Arginina/genética , Neoplasias Cutâneas/metabolismo , Raios Ultravioleta
19.
Biochim Biophys Acta ; 1822(2): 293-300, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22119597

RESUMO

There have been many reports of mitochondrial DNA (mtDNA) mutations associated with human malignancies. We have observed allelic instability in UV-induced cutaneous tumors at the mt-Tr locus encoding the mitochondrial tRNA for arginine. We examined the effects of somatic alterations at this locus by modeling the change in a uniform nuclear background by generating cybrids harboring allelic variation at mt-Tr. We utilized the naturally occurring mtDNA variation at mt-Tr within the BALB/cJ (BALB) and C57BL/6J (B6) strains of Mus musculus to transfer their mitochondria into a mouse ρ(0) cell line that lacked its own mtDNA. The BALB haplotype containing the mt-Tr 9821insA allele produced significant changes in cellular respiration (resulting in lowered ATP production), but increased rates of cellular proliferation in cybrid cells. Furthermore, the mtDNA genotype associated with UV-induced tumors endowed the cybrid cells with a phenotype of resistance to UV-induced apoptosis and enhanced migration and invasion capabilities. These studies support a role for mtDNA changes in cancer.


Assuntos
Desequilíbrio Alélico , Transformação Celular Neoplásica/genética , DNA Mitocondrial/genética , Mitocôndrias/genética , Alelos , Animais , Antioxidantes/metabolismo , Apoptose/genética , Arginina/genética , Arginina/metabolismo , Linhagem Celular , Movimento Celular/genética , Núcleo Celular/genética , Proliferação de Células , Respiração Celular/genética , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Loci Gênicos , Variação Genética , Haplótipos/genética , Células Híbridas/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Mutação/genética , Invasividade Neoplásica/genética , Fenótipo , RNA de Transferência/genética
20.
Mitochondrion ; 10(2): 94-101, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19836469

RESUMO

Transplant recipients have an elevated risk of skin cancer, with a 65- to 250-fold increase in squamous cell carcinoma. Usage of the immunosuppressant cyclosporine A (CsA) is associated with the development of skin cancer. We hypothesized that the increased incidence of skin cancer was due to the action of CsA within keratinocyte mitochondria where it can inhibit mitochondrial permeability transition pore (MPTP) opening. Normally, MPTP opening is induced by oxidative stress such as that caused by UV light and leads to cell death, thereby eliminating a cell that has been exposed to genotoxic insult. However, in the presence of CsA, damaged cells may survive and consequently form tumors. To test this hypothesis, we treated keratinocytes with levels of CsA used therapeutically in transplant patients and assessed their viability following UVA-irradiation. CsA prevented cell death by inhibiting MPTP opening, even though the levels of oxidative stress were increased markedly. Nim811, a non-immunosuppressive drug that can block the MPTP had a similar effect while the immunosuppressive drug tacrolimus that does not interact with the mitochondria had no effect. These findings suggest that CsA may promote skin cancer in transplant patients by allowing keratinocyte survival under conditions of increased genotoxic stress.


Assuntos
Morte Celular , Ciclosporina/farmacologia , Imunossupressores/farmacologia , Queratinócitos/efeitos dos fármacos , Proteínas de Transporte da Membrana Mitocondrial/antagonistas & inibidores , Neoplasias Cutâneas , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Humanos , Poro de Transição de Permeabilidade Mitocondrial , Transplante de Órgãos/efeitos adversos , Raios Ultravioleta
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