Faculty Bibliography

Accumulation of proteins in the endoplasmic reticulum (ER) typically induces stress and initiates the unfolded protein response (UPR) to facilitate recovery. If homeostasis is not restored, apoptosis is induced. However, adaptation to chronic UPR activation can increase resistance to subsequent acute ER stress. We therefore investigated adaptive mechanisms in Oculocutaneous albinism type 2 (Oca2)-null melanocytes where UPR signaling is arrested despite continued tyrosinase accumulation leading to resistance to the chemical ER stressor thapsigargin. Although thapsigargin triggers UPR activation, instead of Perk-mediated phosphorylation of eIF2alpha, in Oca2-null melanocytes, eIF2alpha was rapidly dephosphorylated upon treatment. Dephosphorylation was mediated by the Gadd34-PP1alpha phosphatase complex. Gadd34-complex inhibition blocked eIF2alpha dephosphorylation and significantly increased Oca2-null melanocyte sensitivity to thapsigargin. Thus, Oca2-null melanocytes adapt to acute ER stress by disruption of pro-apoptotic Perk signaling, which promotes cell survival. This is the first study to demonstrate rapid eIF2alpha dephosphorylation as an adaptive mechanism to ER stress.

The coexistence of abnormal keratinization and aberrant pigmentation in a number of cornification disorders has long suggested a mechanistic link between these two processes. Here, we deciphered the genetic basis of Cole disease, a rare autosomal-dominant genodermatosis featuring punctate keratoderma, patchy hypopigmentation, and uncommonly, cutaneous calcifications. Using a combination of exome and direct sequencing, we showed complete cosegregation of the disease phenotype with three heterozygous ENPP1 mutations in three unrelated families. All mutations were found to affect cysteine residues in the somatomedin-B-like 2 (SMB2) domain in the encoded protein, which has been implicated in insulin signaling. ENPP1 encodes ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1), which is responsible for the generation of inorganic pyrophosphate, a natural inhibitor of mineralization. Previously, biallelic mutations in ENPP1 were shown to underlie a number of recessive conditions characterized by ectopic calcification, thus providing evidence of profound phenotypic heterogeneity in ENPP1-associated genetic diseases.

A 14-year-old boy presented with a 2-month history of recurrent crops of tender, erythematous papules. Cultures for infectious organisms (viral and bacterial) were negative. Biopsies revealed a neutrophil-dense infiltrate with numerous enlarged mononuclear cells reactive for CD30, CD3, and CD4 with a small subset reactive for CD56, TIA1, and GranzymeB. Special stains for fungal and bacterial microorganisms were negative. A diagnosis of neutrophilrich (pyogenic) lymphomatoid papulosis (LyP) was made. Classic LyP is rare in children, and the neutrophil-rich variant has not been described extensively in the literature. In this histopathologic setting, the atypical lymphocytes may be obscured but made more apparent with immunohistochemistry. Cases of neutrophil-rich anaplastic large cell lymphoma have been described and have a similar histologic appearance to our case but are generally in adults and present as solitary tumors on the face. The histopathologic differential diagnosis includes benign processes with CD30+ mononuclear cells in addition to infection processes and neutrophilic dermatoses

IMPORTANCE Crouzon syndrome with acanthosis nigricans is a distinct disorder caused by a mutation in the FGFR3 gene, featuring craniosynostosis, characteristic facial features, and atypical and extensive acanthosis nigricans. Other cutaneous findings have not been thoroughly described. OBSERVATIONS We report 6 cases and summarize the existing literature with regard to the cutaneous manifestations of this disorder. All patients have widespread, early-onset acanthosis nigricans. Patients often have prominent hypopigmented scars at surgical sites and nevi arising early in childhood. CONCLUSIONS AND RELEVANCE In addition to craniofacial malformations, Crouzon syndrome with acanthosis nigricans results in characteristic cutaneous findings.

INTRODUCTION: Acne vulgaris is one of the most common skin conditions in children and adolescents. The presentation, differential diagnosis, and association of acne with systemic pathology differs by age of presentation. Current acknowledged guidelines for the diagnosis and management of pediatric acne are lacking, and there are variations in management across the spectrum of primary and specialty care. The American Acne and Rosacea Society convened a panel of pediatric dermatologists, pediatricians, and dermatologists with expertise in acne to develop recommendations for the management of pediatric acne and evidence-based treatment algorithms. METHODS: Ten major topic areas in the diagnosis and treatment of pediatric acne were identified. A thorough literature search was performed and articles identified, reviewed, and assessed for evidence grading. Each topic area was assigned to 2 expert reviewers who developed and presented summaries and recommendations for critique and editing. Furthermore, the Strength of Recommendation Taxonomy, including ratings for the strength of recommendation for a body of evidence, was used throughout for the consensus recommendations for the evaluation and management of pediatric acne. Practical evidence-based treatment algorithms also were developed. RESULTS: Recommendations were put forth regarding the classification, diagnosis, evaluation, and management of pediatric acne, based on age and pubertal status. Treatment considerations include the use of over-the-counter products, topical benzoyl peroxide, topical retinoids, topical antibiotics, oral antibiotics, hormonal therapy, and isotretinoin. Simplified treatment algorithms and recommendations are presented in detail for adolescent, preadolescent, infantile, and neonatal acne. Other considerations, including psychosocial effects of acne, adherence to treatment regimens, and the role of diet and acne, also are discussed. CONCLUSIONS: These expert recommendations by the American Acne and Rosacea Society as reviewed and endorsed by the American Academy of Pediatrics constitute the first detailed, evidence-based clinical guidelines for the management of pediatric acne including issues of special concern when treating pediatric patients.

IMPORTANCE: Controversy exists regarding strategies for diagnosis and management of Spitz nevi, a type of melanocytic neoplasm that most often develops in children. OBJECTIVE: To determine the beliefs, behaviors, and experiences of pediatric dermatologists with regard to Spitz nevi. DESIGN: Anonymous web-based survey. SETTING: Private and academic dermatology practices. PARTICIPANTS: Respondents included 175 pediatric dermatologists from the United States and around the world, representing a 51.1% response rate (175 of 342). Analyses were limited to the 144 respondents whose practices included at least 50% children (younger than 18 years). MAIN OUTCOME MEASURES: Assessment of the following with regard to Spitz nevi: frequency of diagnosis, general beliefs, techniques used for evaluation (eg, dermoscopy and biopsy), management strategies, and observed outcomes. RESULTS: Collectively, respondents had seen approximately 20 000 Spitz nevi; 67.6% (96 of 142) had diagnosed at least 6 Spitz nevi yearly, whereas 90.1% (128 of 142) had diagnosed no more than 2 prepubertal melanomas in the past 5 years. Ninety-six percent of respondents (95.8%; 136 of 142) categorized typical Spitz nevi as benign. Eighty percent of respondents (79.6%; 113 of 142) used dermatoscopy, and 96.5% (137 of 142) avoided partial biopsies of Spitz nevi. In children with a suspected Spitz nevus, clinical follow-up was chosen by 49.3% (69 of 140) of respondents for a small, stable nonpigmented lesion and by 29.7% (41 of 138) for a pigmented lesion with a typical starburst pattern seen via dermatoscopy. Predictors of clinical follow-up of the latter lesion included believing that Spitz nevi are not melanoma precursors (P = .04). Forty-seven percent (62 of 132) of respondents had observed involution of Spitz nevi. No deaths had resulted from the approximately 10 000 Spitz nevi or atypical spitzoid neoplasms seen by the 91 respondents with academic or hospital-based practices. CONCLUSIONS AND RELEVANCE: The results of our survey support conservative management of Spitz nevi in children, with clinical follow-up representing an option for typical lesions. This represents an important difference from strategies used for management of these lesions in adults.

Mebendazole (MBZ) was identified as a promising therapeutic on the basis of its ability to induce apoptosis in melanoma cell lines through a B-cell lymphoma 2 (BCL2)-dependent mechanism. We now show that in a human xenograft melanoma model, oral MBZ is as effective as the current standard of care temozolomide in reducing tumor growth. Inhibition of melanoma growth in vivo is accompanied by phosphorylation of BCL2 and decreased levels of X-linked inhibitor of apoptosis (XIAP). Reduced expression of XIAP on treatment with MBZ is partially mediated by its proteasomal degradation. Furthermore, exposure of melanoma cells to MBZ promotes the interaction of SMAC/DIABLO with XIAP, thereby alleviating XIAP's inhibition on apoptosis. XIAP expression on exposure to MBZ is indicative of sensitivity to MBZ as MBZ-resistant cells do not show reduced levels of XIAP after treatment. Resistance to MBZ can be reversed partially by siRNA knockdown of cellular levels of XIAP. Our data indicate that MBZ is a promising antimelanoma agent on the basis of its effects on key antiapoptotic proteins.

Persistent paraprotein production in plasma cells necessitates a highly developed rough endoplasmic reticulum (ER) that is unusually susceptible to perturbations in protein synthesis. This biology is believed to account for the exquisite sensitivity of multiple myeloma (MM) to the proteasomal inhibitor bortezomib (BTZ). Despite remarkable response rates to BTZ in MM, BTZ carries the potential for serious side-effects and development of resistance. We, therefore, sought to identify therapeutic combinations that effectively disrupt proteostasis in order to provide new potential treatments for MM. We found that sulforaphane, a dietary isothiocyanate found in cruciferous vegetables, inhibits TNFalpha-induced Ikappabeta proteasomal degradation in a manner similar to BTZ. Like BTZ, sulforaphane synergistically enhances the cytotoxicity of arsenic trioxide (ATO), an agent with clinical activity in MM. ATO and sulforaphane co-treatment augmented apoptotic induction as demonstrated by cleavage of caspase-3, -4 and PARP. The enhanced apoptotic response was dependent upon production of reactive oxygen species (ROS) as demonstrated by glutathione depletion and partial inhibition of the apoptotic cascade after pretreatment with the radical scavenger N-acetyl-cysteine (NAC). Combination treatment resulted in enhanced ER stress signaling and activation of the unfolded protein response (UPR), indicative of perturbation of proteostasis. Specifically, combination treatment caused elevated expression of the molecular chaperone HSP90 (heat shock protein 90) along with increased PERK (protein kinase RNA-like endoplasmic reticulum kinase) and eIF2alpha phosphorylation and XBP1 (X-box binding protein 1) splicing, key indicators of UPR activation. Moreover, increased splicing of XBP1 was apparent upon combination treatment compared to treatment with either agent alone. Sulforaphane in combination with ATO effectively disrupts protein homeostasis through ROS generation and induction of ER stress to culminate in inhibition of protein secretion and apoptotic induction in MM. Our results suggest that sulforaphane deserves further investigation in combination with ATO in the treatment of MM.