TERT and TERT promoter in melanocytic neoplasms: Current concepts in pathogenesis, diagnosis, and prognosis

Background and objectiveLocated on chromosome locus 5p15.33, telomerase reverse transcriptase (TERT or hTERT) encodes the catalytic subunit of telomerase which permits lengthening and preservation of telomeres following mitosis. Mutations in TERT promoter (TERT‐p) upregulate expression of TERT, allowing survival of malignant cells and tumor progression in wide variety of malignancies including melanoma. The objective of this review is to examine the roles of TERT and TERT‐p in the pathogenesis, diagnosis, and prognostication of cutaneous melanoma.MethodsAll studies of TERT or TERT‐p in cutaneous melanocytic neoplasms with the following inclusion criteria were reviewed: publication date between 2010 and 2019, English language, and series of ≥3 cases were reviewed for evidence supporting the role of TERT in pathogenesis, diagnosis, and prognosis. Studies with <3 cases or focused primarily on mucosal or uveal melanocytic tumors were excluded.Results and conclusionTERT‐p mutations are frequent in chronic and non‐chronic sun damage melanoma and correlate with adverse prognosis, inform pathogenesis, and may provide diagnostic support. While TERT‐p mutations are uncommon in acral melanoma, TERT copy number gains and gene amplification predict reduced survival. Among atypical spitzoid neoplasms, TERT‐p mutations identify biologically aggressive tumors and support the diagnosis of spitzoid melanoma. TERT‐p methylation may have prognostic value in pediatric conventional melanoma and drive tumorigenesis in melanoma arising within congenital nevi. Finally, TERT‐p mutations may aid in the differentiation of recurrent nevi from recurrent melanoma.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156143/2/cup13691.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156143/1/cup13691_am.pd

Appropriate use criteria in dermatopathology: Initial recommendations from the American Society of Dermatopathology

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145218/1/cup13142.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145218/2/cup13142_am.pd

Thioredoxin Reductase Is Essential for Viability in the Fungal Pathogen Cryptococcus neoformans

Thioredoxin reductase (TRR1) is an important component of the thioredoxin oxidative stress resistance pathway. Here we show that it is induced during oxidative and nitrosative stress and is preferentially localized to the mitochondria in Cryptococcus neoformans. The C. neoformans TRR1 gene encodes the low-molecular-weight isoform of the thioredoxin reductase enzyme, which shares little homology with that of its mammalian host. By replacing the endogenous TRR1 promoter with an inducible copper transporter promoter, we showed that Trr1 appears to be essential for viability of this pathogenic fungus, making it a potential antifungal target

A case of topical imiquimod induced fatigue

Topical imiquimod is used for a variety of common dermatologic lesions, including melanoma in-situ. As an immunomodulator, it is relatively well tolerated with minimal side effects, including scaling, erythema, and edema. Here we present a rare systemic adverse effect, where our patient experienced debilitating severe fatigue when applying imiquimod to a single lesion. Clinicians should be mindful of this side effect and counsel patients appropriately

Granuloma Annulare in the Setting of Secukinumab

Granuloma annulare (GA) is a common benign inflammatory skin condition classically presenting as skin-colored to erythematous dermal papules and annular plaques. Histologically, GA displays a dermal granulomatous infiltrate with palisaded histiocytes surrounding focally altered collagen. The exactly etiology of GA remains unknown, but it has been associated with trauma, various infections, diabetes mellitus, malignancy, thyroid disease, dyslipidemia, and several medications. In 2017, a case of GA developing in a patient treated with the interleukin 17A antagonist secukinumab was reported. Here we report a second case of GA in association with secukinumab use

Distinct Stress Responses of Two Functional Laccases in Cryptococcus neoformans Are Revealed in the Absence of the Thiol-Specific Antioxidant Tsa1

Laccases are thought to be important to the virulence of many fungal pathogens by producing melanin, a presumed oxygen radical scavenger. A laccase in Cryptococcus neoformans has been shown to synthesize melanin and contributes to the virulence and the survival in macrophages of this fungal pathogen. One C. neoformans laccase gene, LAC1, previously called CNLAC1, has been extensively studied, and we describe a homologous gene, LAC2, that is found 8 kb away from LAC1 in the genome. In this study we report a role for both laccases, in addition to the thiol peroxidase, Tsa1, in oxidative and nitrosative stress resistance mechanisms of C. neoformans. With use of real-time PCR, similar changes in expression of the two laccase genes occur in response to oxidative and nitrosative stresses, but only the regulation of the LAC2 gene during stress is influenced by Tsa1. Both laccases contribute to melanin production using L-dopa as a substrate and are differentially localized in the cell based on green fluorescent protein fusions. A single deletion of either LAC1 or LAC2 alone had no effect on sensitivity to H(2)O(2) or nitric oxide. However, deletion of either LAC1 or LAC2 in combination with a TSA1 deletion resulted in a slight peroxide sensitivity, and a lac2Δ tsa1Δ deletion strain was sensitive to nitric oxide stress. In addition, the deletion of both laccases reduces survival of C. neoformans in primary macrophages. Based on our expression and functional analysis, we propose a novel model for the interaction of these two systems, which are both important for virulence