RESUMO
Healthy skin is a mosaic of wild-type and mutant clones1,2. Although injury can cooperate with mutated Ras family proteins to promote tumorigenesis3-12, the consequences in genetically mosaic skin are unknown. Here we show that after injury, wild-type cells suppress aberrant growth induced by oncogenic Ras. HrasG12V/+ and KrasG12D/+ cells outcompete wild-type cells in uninjured, mosaic tissue but their expansion is prevented after injury owing to an increase in the fraction of proliferating wild-type cells. Mechanistically, we show that, unlike HrasG12V/+ cells, wild-type cells respond to autocrine and paracrine secretion of EGFR ligands, and this differential activation of the EGFR pathway explains the competitive switch during injury repair. Inhibition of EGFR signalling via drug or genetic approaches diminishes the proportion of dividing wild-type cells after injury, leading to the expansion of HrasG12V/+ cells. Increased proliferation of wild-type cells via constitutive loss of the cell cycle inhibitor p21 counteracts the expansion of HrasG12V/+ cells even in the absence of injury. Thus, injury has a role in switching the competitive balance between oncogenic and wild-type cells in genetically mosaic skin.
Assuntos
Proliferação de Células , Genes ras , Mosaicismo , Mutação , Pele , Proteínas ras , Ciclo Celular , Proliferação de Células/genética , Receptores ErbB/metabolismo , Proteínas ras/genética , Proteínas ras/metabolismo , Pele/citologia , Pele/lesões , Pele/metabolismo , Pele/patologia , Inibidor de Quinase Dependente de Ciclina p21/deficiência , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismoRESUMO
OBJECTIVES: Hidradenitis suppurativa (HS) is a chronic inflammatory condition characterized by painful nodules, draining tunnels, and fibrotic scarring in intertriginous, hair-bearing areas. The pathogenesis involves follicular occlusion and subsequent rupture, leading to uncontrolled inflammation. Treatment options for HS are limited and lack universal effectiveness. Laser hair removal (LHR) has been explored as a potential treatment; however, the efficacy and appropriate laser modalities remain unclear. This systematic review examined the efficacy and adverse effects of LHR in HS. METHODS: A comprehensive literature search was conducted from inception to September 2023 in Ovid MEDLINE, Ovid Embase, and The Cochrane Library (Wiley) with predefined inclusion and exclusion criteria, and a meta-analysis was conducted. RESULTS: Ten studies were selected (n = 227 total patients) and included six randomized controlled trials, two nonrandomized experimental studies, and two case series. Various laser modalities, including long-pulsed neodymium-doped yttrium aluminum garnet (Nd:YAG) (n = 115), intense pulsed light (n = 18), Alexandrite (n = 54), intralesional 1064 nm diode (n = 20), and combined fractional CO2 and long-pulsed Nd:YAG laser (n = 20), consistently demonstrated significant improvement in HS disease severity, irrespective of the disease scoring method used. Minimal adverse effects (primarily mild pain and erythema) were reported. A meta-analysis of three studies utilizing long-pulsed Nd:YAG laser demonstrated a standardized mean difference in disease severity of -1.68 (95% confidence interval: -2.99; -0.37), favoring treatment with LHR for HS. CONCLUSIONS: Hair follicles are key in HS pathogenesis and all included studies showed a significant improvement in HS disease severity after LHR regardless of the laser device used, likely related to hair follicle unit destruction. HS is a complex and heterogenous condition, and multiple disease scoring methods complicate outcome comparisons across studies. However, LHR, utilizing various techniques, is an effective treatment option for HS with minimal adverse effects.
Assuntos
Remoção de Cabelo , Hidradenite Supurativa , Humanos , Hidradenite Supurativa/cirurgia , Hidradenite Supurativa/terapia , Remoção de Cabelo/métodos , Resultado do Tratamento , Terapia a Laser/métodos , Lasers de Estado Sólido/uso terapêuticoRESUMO
Cells in healthy tissues acquire mutations with surprising frequency. Many of these mutations are associated with abnormal cellular behaviours such as differentiation defects and hyperproliferation, yet fail to produce macroscopically detectable phenotypes. It is currently unclear how the tissue remains phenotypically normal, despite the presence of these mutant cells. Here we use intravital imaging to track the fate of mouse skin epithelium burdened with varying numbers of activated Wnt/ß-catenin stem cells. We show that all resulting growths that deform the skin tissue architecture regress, irrespective of their size. Wild-type cells are required for the active elimination of mutant cells from the tissue, while utilizing both endogenous and ectopic cellular behaviours to dismantle the aberrant structures. After regression, the remaining structures are either completely eliminated or converted into functional skin appendages in a niche-dependent manner. Furthermore, tissue aberrancies generated from oncogenic Hras, and even mutation-independent deformations to the tissue, can also be corrected, indicating that this tolerance phenomenon reflects a conserved principle in the skin. This study reveals an unanticipated plasticity of the adult skin epithelium when faced with mutational and non-mutational insult, and elucidates the dynamic cellular behaviours used for its return to a homeostatic state.
Assuntos
Células Epiteliais/citologia , Células Epiteliais/metabolismo , Homeostase , Mutação , Fenótipo , Pele/citologia , Animais , Camundongos , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Células-Tronco/citologia , Células-Tronco/metabolismo , Proteínas Wnt/metabolismo , beta Catenina/genética , beta Catenina/metabolismoRESUMO
BACKGROUND: Perineural invasion (PNI) is a known risk factor for recurrence, metastasis, and death in cutaneous squamous cell carcinoma (cSCC). Current staging systems include PNI, but none define its extent or severity. OBJECTIVE: To identify histopathologic features of cSCC with PNI that may be associated with adverse outcomes. MATERIALS AND METHODS: This is a retrospective cohort study that included 45 patients with cSCC and PNI treated with surgical excision. Histopathologic slides were analyzed for 5 features of PNI: largest affected nerve diameter, number of nerves affected, depth of nerve involvement, intra- versus extratumoral PNI, and focal versus circumferential PNI. RESULTS: The median largest affected nerve diameter was 0.13 mm, and the median number of nerve structures involved was 4. After a median follow-up time of 24 months, 6 patients developed adverse outcomes, including 2 local recurrences, 4 metastases, and 2 tumor-related deaths. Univariate logistic regression analysis revealed that nerve diameter and number of affected nerves were significantly associated with adverse outcome. A composite PNI score, calculated from 5 histopathologic features, was the strongest predictor of adverse outcome (p = .020). CONCLUSION: Histopathologic features of PNI can be quantified with a composite PNI score that is significantly associated with adverse outcomes in cSCC.
Assuntos
Carcinoma de Células Escamosas/patologia , Estadiamento de Neoplasias , Nervos Periféricos/patologia , Neoplasias Cutâneas/patologia , Biópsia , Seguimentos , Humanos , Invasividade Neoplásica , Estudos Retrospectivos , Fatores de RiscoRESUMO
Unmet dermatologic needs of the uninsured patient population are important to identify and address, especially as the COVID-19 pandemic has introduced additional barriers of access to care. We describe the successful collaboration between a student-run free clinic and dermatology practice since 2012, highlighting excellent time to appointment intervals and resolution rates as well as the associated modest financial cost. We believe that the information provided in our report may serve as a proof of concept and facilitate the implementation of such collaborations throughout the United States.
Assuntos
COVID-19 , Clínica Dirigida por Estudantes , Humanos , Pessoas sem Cobertura de Seguro de Saúde , Pandemias , Encaminhamento e Consulta , SARS-CoV-2 , Estados UnidosRESUMO
Ultraviolet radiation (UVR) exposure is well established as the major environmental risk factor for the development of melanoma, cutaneous squamous cell carcinoma (cSCC), and basal cell carcinoma (BCC). Additional risk factors including genetic mutations, other environmental agents, and immune status are important in modulating the effects of UVR. Dermatologists advocate a multi-pronged approach to minimizing UVR exposure including lifestyle modifications, UVR protective clothing, and topically applied sun-protective products, i.e. sunscreen. New Federal Drug Administration (FDA) regulations on sunscreen have brought certain long-standing ingredients in sunscreen products under scrutiny. The FDA's proposed rule for over the counter (OTC) monograph states that the inorganic sunscreens, zinc oxide and titanium dioxide, were found to be "generally recognized as safe and effective," but cite insufficient evidence to grant organic sunscreens the same designation. This proposed rule by the FDA and our increasing understanding of multifactorial mechanisms of UVR damage are an impetus for innovation and advances in sun protective technology. A complete set of strategies designed to limit the risk of UV-induced skin cell malignant transformation and tumor development must address the fuller consideration of genetic, environmental, and immune factors that cooperatively drive cutaneous carcinogenesis. Recent advances in our understanding of the biochemical processes underpinning UVR associated cutaneous cellular damage, genotoxicity, and clonal expansion provide investigators with a spectrum of opportunities for technologic innovation in the prevention of skin cancer. Strategies to improve upon current topical sunscreen formulations have strived for broader UVR spectral coverage, more favorable aesthetics, increased adherence, and minimal penetration into the living epidermis. In addition to improved sunscreens, future topical therapies may target processes within the epidermis that contribute to carcinogenesis. These include reactive species quenching, delivery of DNA repair enzymes, and targeting of cytokines essential to the proliferation of mutant keratinocytes.
Assuntos
Exposição Ambiental/prevenção & controle , Neoplasias Cutâneas , Protetores Solares , Raios Ultravioleta/efeitos adversos , Exposição Ambiental/efeitos adversos , Humanos , Fotobiologia , Neoplasias Cutâneas/epidemiologia , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/prevenção & controle , Fator de Proteção Solar , Protetores Solares/classificação , Protetores Solares/farmacologiaAssuntos
Acreditação , Dermatologia , Educação de Pós-Graduação em Medicina , Estudos Transversais , Estados Unidos , Humanos , Dermatologia/normas , Educação de Pós-Graduação em Medicina/normas , Internato e Residência/estatística & dados numéricos , Inquéritos e Questionários/estatística & dados numéricos , Cirurgia Plástica/normas , Diretores Médicos , Masculino , FemininoAssuntos
Algoritmos , Doenças Labiais/diagnóstico , Doenças Labiais/cirurgia , Adulto , Idoso , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/cirurgia , Queilite/diagnóstico , Queilite/cirurgia , Diagnóstico Diferencial , Feminino , Humanos , Neoplasias Labiais/diagnóstico , Neoplasias Labiais/cirurgia , Lúpus Eritematoso Discoide/diagnóstico , Lúpus Eritematoso Discoide/cirurgia , Masculino , Pessoa de Meia-IdadeAssuntos
Carcinoma de Células Escamosas/diagnóstico , Doença Enxerto-Hospedeiro/complicações , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Neoplasias Labiais/diagnóstico , Cirurgia de Mohs , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Adulto , Carcinoma de Células Escamosas/etiologia , Carcinoma de Células Escamosas/cirurgia , Humanos , Neoplasias Labiais/etiologia , Neoplasias Labiais/cirurgia , MasculinoRESUMO
Tissue regeneration and maintenance rely on coordinated stem cell behaviours. This orchestration can be impaired by oncogenic mutations leading to cancer. However, it is largely unclear how oncogenes perturb stem cells' orchestration to disrupt tissue. Here we used intravital imaging to investigate the mechanisms by which oncogenic Kras mutation causes tissue disruption in the hair follicle. Through longitudinally tracking hair follicles in live mice, we found that KrasG12D, a mutation that can lead to squamous cell carcinoma, induces epithelial tissue deformation in a spatiotemporally specific manner, linked with abnormal cell division and migration. Using a reporter mouse capture real-time ERK signal dynamics at the single-cell level, we discovered that KrasG12D, but not a closely related mutation HrasG12V, converts ERK signal in stem cells from pulsatile to sustained. Finally, we demonstrated that interrupting sustained ERK signal reverts KrasG12D-induced tissue deformation through modulating specific features of cell migration and division.
Assuntos
Movimento Celular , Folículo Piloso , Mutação , Proteínas Proto-Oncogênicas p21(ras) , Animais , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Camundongos , Folículo Piloso/metabolismo , Sistema de Sinalização das MAP Quinases/genética , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/genética , Camundongos Transgênicos , Células-Tronco/metabolismo , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Humanos , Feminino , Ativação EnzimáticaRESUMO
Reconstruction of nasal defects secondary to Mohs micrographic surgery (MMS) presents particular challenges related to the complex topography, skin quality, tissue laxity, and functional and aesthetic concerns of the region. Factors affecting outcomes resulting from second intent healing (SIH) on the nose have not been well described. The purpose of the study was to identify factors impacting outcomes of SIH for nasal tumors following MMS. Retrospective analysis was performed of all nasal lesions treated with MMS followed by SIH from a single surgical center over a 1.5-year period. Ninety-six cases were included. Chart review was performed, and data were collected including age, gender, nasal site, tumor type, defect size, depth, and number of MMS stages. Pre- and post-operative follow-up photographs were available for all cases. All five authors evaluated the photographs using the modified Manchester scar scale. Analysis was then conducted to identify features associated with good outcomes. Of the 96 tumors, 39 lesions (40.6%) were located on the nasal tip (including supratip), 32 (33.3%) on the ala/alar groove, 17 (17.7%) on the sidewall, and 8 (8.3%) on the dorsum. The average defect size was 0.83 cm2 (diameter of 1.06 cm ± 0.4). Defect diameter and defect depth were the factors that significantly impacted scar outcome (p < 0.001) in multivariate analysis. No significant functional deficits were reported. This retrospective study suggests that nasal defects with area less than 0.83 cm2 (or 1.06 cm diameter) and depth of defect not extending beyond the superficial fat healed well by SIH regardless of location on the nose.
Assuntos
Rinoplastia , Neoplasias Cutâneas , Humanos , Rinoplastia/métodos , Estudos Retrospectivos , Retalhos Cirúrgicos , Cicatriz/cirurgia , Cirurgia de Mohs/efeitos adversos , Neoplasias Cutâneas/cirurgiaRESUMO
Acne vulgaris is one of the most common skin disorders worldwide. It typically affects skin areas with a high density of sebaceous glands such as the face, upper arms, chest, and/or back. Historically, the majority of research efforts have focused on facial acne vulgaris, even though approximately half of patients with facial lesions demonstrate truncal involvement. Truncal acne vulgaris is challenging to treat and poses a significant psychosocial burden on patients. Despite these characteristics, studies specifically examining truncal acne vulgaris are limited, with treatment guidelines largely derived from facial protocols. Therefore, truncal acne remains an understudied clinical problem. Here, we provide a clinically focused review on the epidemiology, evaluation, and available treatment options for truncal acne vulgaris. In doing so, we highlight knowledge gaps with the goal of spurring further investigation into the management of truncal acne vulgaris.
Assuntos
Acne Vulgar , Cicatriz , Humanos , Cicatriz/patologia , Acne Vulgar/tratamento farmacológico , Tronco/patologia , Pele/patologia , Glândulas SebáceasRESUMO
Cosmetic and laser procedures are increasingly popular among patients and are skills in which dermatologists are regarded as well trained. Most dermatology residents intend to incorporate cosmetic procedures into their practice and prefer to learn such procedures during residency through direct patient care. However, there are notable challenges in optimizing how residents are trained in cosmetic and laser dermatology. To address these barriers and elevate the practice of cosmetic dermatology in academic medicine, the Association of Academic Cosmetic Dermatology (AACD) was founded in 2021 as the lead professional society for dermatologists who direct the education of resident trainees in cosmetic and laser dermatology. The AACD, a group of board-certified dermatologists who teach cosmetic and laser dermatology to residents, aims to improve cosmetic dermatology education through collaboration, research, and advocacy.
Assuntos
Dermatologia , Internato e Residência , Humanos , Dermatologia/educação , Currículo , Inquéritos e QuestionáriosRESUMO
Cosmetic dermatology is a key subspecialty of academic dermatology. As such, academic centers are expected to demonstrate excellence in the teaching of cosmetic dermatology skills to trainees, the clinical delivery of cosmetic dermatology services to patients, and the performance of clinical research that advances knowledge and uncovers new therapies in cosmetic dermatology. The Association of Academic Cosmetic Dermatology (AACD), a newly formed medical professional society, includes as its principal aims the support of all of these areas. AACD is comprised of group of board-certified dermatologists who teach cosmetic and laser dermatology at US dermatology residency programs. An expert panel constituted by the AACD recently convened a workshop to review gaps pertaining to academic cosmetic dermatology. This panel considered needs and potential corrective initiatives in three domains: resident education, patient experience, and clinical research. The work of the panel was used to develop a roadmap, which was adopted by consensus, and which will serve to guide the AACD moving forward.
Assuntos
Dermatologia , Internato e Residência , Humanos , Dermatologia/educação , Assistência ao Paciente , Sociedades MédicasRESUMO
Importance: Laser-assisted drug delivery (LADD) is used for various medical and cosmetic applications. However, there is insufficient evidence-based guidance to assist clinicians performing LADD. Objective: To develop recommendations for the safe and effective use of LADD. Evidence Review: A systematic literature review of Cochrane Central Register of Controlled Trials, Embase, and MEDLINE was conducted in December 2019 to identify publications reporting research on LADD. A multidisciplinary panel was convened to draft recommendations informed by the systematic review; they were refined through 2 rounds of Delphi survey, 2 consensus meetings, and iterative review by all panelists until unanimous consensus was achieved. Findings: Of the 48 published studies of ablative fractional LADD that met inclusion criteria, 4 were cosmetic studies; 21, oncologic; and 23, medical (not cosmetic/oncologic), and 6 publications of nonablative fractional LADD were included at the request of the expert panel, producing a total of 54 studies. Thirty-four studies (63.0%) were deemed to have low risk of bias, 17 studies (31.5%) had moderate risk, and 3 (5.5%) had serious risk. The key findings that informed the guidelines developed by the expert panel were as follows: LADD is safe in adults and adolescents (≥12 years) with all Fitzpatrick skin types and in patients with immunosuppression; it is an effective treatment for actinic keratosis, cutaneous squamous cell carcinoma in situ, actinic cheilitis, hypertrophic scars, and keloids; it is useful for epidermal and dermal analgesia; drug delivery may be increased through the application of heat, pressure, or occlusion, or by using an aqueous drug solution; laser settings should be selected to ensure that channel diameter is greater than the delivered molecule; antibiotic prophylaxis is not recommended, except with impaired wound healing; antiviral prophylaxis is recommended when treating the face and genitalia; and antifungal prophylaxis is not recommended. The guideline's 15 recommendations address 5 areas of LADD use: (I) indications and contraindications; (II) parameters to report; (III) optimization of drug delivery; (IV) safety considerations; and (V) prophylaxis for bacterial, viral, and fungal infections. Conclusions and Relevance: This systematic review and Delphi consensus approach culminated in an evidence-based clinical practice guideline for safe and effective use of LADD in a variety of applications. Future research will further improve our understanding of this novel treatment technique.