Chronic ulcer in a patient with essential thrombocythemia taking hydroxyurea.

Chronic skin ulcers in patients with suspected pyoderma gangrenosum can, on closer inspection and further workup, have a different cause. Recognition of key features on clinical examination such as the presence of atrophie blanche is key to avoid misdiagnosis of pyoderma gangrenosum and its subsequent treatment with high-dose corticosteroids and other immunosuppressive medications.

Mucocutaneous toxicities from MEK inhibitors: a scoping review of the literature.

BACKGROUND: MEK inhibitors cause a wide spectrum of mucocutaneous toxicities which can delay or interrupt life-saving therapy. PURPOSE: To summarize the morphology, incidence, and clinical presentation of mucocutaneous toxicities from MEK inhibitors via a scoping review of the literature. METHODS: We conducted a scoping review of the published literature, including clinical trials, retrospective and prospective studies, reviews, and case reports and series. All included literature was analyzed by a panel of pediatric and adult oncodermatologists. RESULTS: Of 1626 initial citations, 227 articles met final inclusion criteria. Our review identified follicular reactions, ocular toxicities, xerosis, eczematous dermatitis, edema, and paronychia as the most common mucocutaneous side effects from MEK inhibitor therapy. Grade 1 and 2 reactions were the most prevalent and were typically managed while continuing treatment; however, grade 3 toxicities requiring dose reductions or treatment interruptions were also reported. CONCLUSION: Mucocutaneous toxicities to MEK inhibitor therapy are common and most often mild in severity. Early recognition and treatment can mitigate disruptions in oncologic therapy.

Causes and Clinical Presentation of Drug-Induced Dermatomyositis: A Systematic Review.

Importance: While several medications are known to induce dermatomyositis (DM), most existing studies are case reports or small case series from a single institution. There is also limited information on DM induced by immune checkpoint inhibitors, which are increasingly used in oncologic therapy. Objective: To characterize causes and clinical presentation of drug-induced DM based on the current literature. Evidence Review: A systematic review was performed in PubMed according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines, from inception to August 22, 2022. Articles meeting preestablished inclusion criteria (written in English and classified as original articles, case reports, literature reviews, and observation letters) were selected and data abstracted. Articles that met the scope of the review were also added from reference lists. When possible, study results were quantitatively combined. Findings: In 134 studies (114 from the literature search and 20 additional studies pulled from reference lists) describing 165 cases, 88 patients (53.3%) were female, and the median (IQR) age was 61 (49-69) years. Among the cases of drug-induced DM, the most common associated medications were hydroxyurea (50 [30.3%]), immune checkpoint inhibitors (27 [16.4%]), statins (22 [13.3%]), penicillamine (10 [6.1%]), and tumor necrosis factor inhibitors (10 [6.1%]). Histopathologic testing, when undertaken, helped establish the diagnosis. There was a median (IQR) of 60 (21-288) days between drug initiation and drug-induced DM onset. History of cancer was reported in 85 cases (51.6%). Conclusions and Relevance: In this systematic review, drug-induced DM was associated with multiple types of medications, including chemotherapies and immunotherapies. It is essential that dermatologists promptly recognize and diagnose drug-induced DM so that they can guide management to minimize interruption of therapy when possible.

Livedoid vasculopathy.

Livedoid vasculopathy is a painful thrombo-occlusive vascular disorder characterized by spontaneous thrombosis in medium-size arterioles, which causes localized hypoxia and skin ulceration. As livedoid vasculopathy is rare, case reports are the primary means of expanding collective knowledge about its presentation and response to various therapies.

Small lymphocytic lymphoma presenting as chronic diffuse lip swelling.

Although rare, small lymphocytic lymphoma can present as chronic lip swelling and papules, thus mimicking the features of orofacial granulomatosis, a chronic inflammatory disorder characterized by subepithelial noncaseating granulomas, or papular mucinosis, characterized by localized dermal mucin deposition of mucin. When assessing lip swelling, one must carefully consider the clinical clues and have a low threshold to perform a diagnostic tissue biopsy, preventing delays in treatment or progression of the lymphoma.

Management of Cutaneous Immune-Related Adverse Events in Patients With Cancer Treated With Immune Checkpoint Inhibitors: A Systematic Review.

IMPORTANCE: There exists a paucity of literature that summarizes the effective management of cutaneous immune-related adverse events (cirAEs) in patients with cancer who are receiving immune checkpoint inhibitors (ICIs). Most published articles are small case series from a single institution. To our knowledge, the spectrum of possible treatments has not been systematically reviewed to highlight the breadth of options when caring for patients with cirAEs. OBJECTIVE: To further characterize the development of subtypes of cirAEs in patients with cancer treated with ICIs and provide recommendations on optimal treatment regimens based on the current literature. EVIDENCE REVIEW: A search was performed in PubMed, Embase European, Web of Science, and Google Scholar on June 26, 2020, according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines, limited to the years 2010 to 2020. Articles that met predetermined inclusion criteria (published between January 1, 2010, and June 1, 2020; written in the English language; and original articles, brief reports, case reports, and research letters that reported primarily on cirAE management) were selected, and data were abstracted. Articles that met the scope of the review were also added from reference lists. When possible, the results of studies that addressed a similar question were combined quantitatively. FINDINGS: In total, 138 studies (87 from the aforementioned literature search and 51 additional studies pulled from the reference lists of included articles) were included that reported on 879 cirAEs. The subtypes of cirAEs included maculopapular, pruritus, lichenoid, immunobullous, psoriasiform, granulomatous, erythema multiforme or Stevens Johnson Syndrome, drug rash with eosinophilia and systemic symptoms, connective tissue disease, hair, oral, and miscellaneous. Treatments for cirAEs included a combination of topical corticosteroids, systemic corticosteroids, steroid-sparing agents, and discontinuation or cessation of immunotherapy. CONCLUSIONS AND RELEVANCE: This systematic review found that treatment with ICIs was associated with many types of skin toxic effects, each with unique treatment options beyond current published guidelines. Further research into key differences between subtypes is critical to improve the care provided to patients with cancer.

The antimicrobial drug pyrimethamine inhibits STAT3 transcriptional activity by targeting the enzyme dihydrofolate reductase.

Cancer is often characterized by aberrant gene expression patterns caused by the inappropriate activation of transcription factors. Signal transducer and activator of transcription 3 (STAT3) is a key transcriptional regulator of many protumorigenic processes and is persistently activated in many types of human cancer. However, like many transcription factors, STAT3 has proven difficult to target clinically. To address this unmet clinical need, we previously developed a cell-based assay of STAT3 transcriptional activity and performed an unbiased and high-throughput screen of small molecules known to be biologically active in humans. We identified the antimicrobial drug pyrimethamine as a novel and specific inhibitor of STAT3 transcriptional activity. Here, we show that pyrimethamine does not significantly affect STAT3 phosphorylation, nuclear translocation, or DNA binding at concentrations sufficient to inhibit STAT3 transcriptional activity, suggesting a potentially novel mechanism of inhibition. To identify the direct molecular target of pyrimethamine and further elucidate the mechanism of action, we used a new quantitative proteome profiling approach called proteome integral solubility alteration coupled with a metabolomic analysis. We identified human dihydrofolate reductase as a target of pyrimethamine and demonstrated that the STAT3-inhibitory effects of pyrimethamine are the result of a deficiency in reduced folate downstream of dihydrofolate reductase inhibition, implicating folate metabolism in the regulation of STAT3 transcriptional activity. This study reveals a previously unknown regulatory node of the STAT3 pathway that may be important for the development of novel strategies to treat STAT3-driven cancers.

Resolution of folliculitis decalvans with medical honey.

Folliculitis decalvans is a rare scarring alopecia that presents with indurated, tender pustules and papules on the vertex and occipital scalp. Although systemic antibiotics with activity against Staphylococcus species provide some symptomatic improvement, folliculitis decalvans remains a significant management challenge and often exhibits a relapsing-and-remitting course. In this report, we posit the potential utility of medical grade honey as a safe and cost-effective adjuvant therapy in the treatment of folliculitis decalvans. We describe a patient with painful, boggy scalp pustules who achieved clearance of his scalp lesions with the addition of Manuka honey. To our knowledge, this report is the first to demonstrate the clinical use of honey in the management of folliculitis decalvans and may lend support to the role of Staphylococcus in the pathogenesis of this disease.

A Case of Fever and Erythema Nodosum-Like Lesions Leading to a New Diagnosis of Gamma-Delta T-Cell Lymphoma Complicated by Hemophagocytic Lymphohistiocytosis.

A 69-year-old Vietnamese female presented with fever and new-onset tender subcutaneous nodules on her trunk and lower extremities initially thought to be clinically consistent with erythema nodosum. A biopsy showed an atypical, predominantly lobular lymphocytic panniculitis with admixed neutrophils, karyorrhectic debris, and histiocytes with subcutaneous fat necrosis. Immunohistochemistry was consistent with gamma-delta T-cell lymphoma. The patient was initiated on a chemotherapy regimen of cyclophosphamide, doxorubicin, vincristine, etoposide, and prednisone (CHOEP) with partial remission, and is currently undergoing evaluation for bone marrow transplant. This case highlights the ability of cutaneous gamma-delta T-cell lymphoma to mimic more common cutaneous conditions such as erythema nodosum, and stresses the importance of a broad differential for new presentation of tender subcutaneous nodules with concomitant systemic symptoms.

The STAT3 Target Gene TNFRSF1A Modulates the NF-κB Pathway in Breast Cancer Cells.

The transcription factor STAT3 is activated inappropriately in 70% of breast cancers, most commonly in triple negative breast cancer (TNBC). Although the transcriptional function of STAT3 is essential for tumorigenesis, the key target genes regulated by STAT3 in driving tumor pathogenesis have remained unclear. To identify critical STAT3 target genes, we treated TNBC cell lines with two different compounds that block STAT3 transcriptional function, pyrimethamine and PMPTP. We then performed gene expression analysis to identify genes whose expression is strongly down-regulated by both STAT3 inhibitors. Foremost among the down-regulated genes was TNFRSF1A, which encodes a transmembrane receptor for TNFα. We showed that STAT3 binds directly to a regulatory region within the TNFRSF1A gene, and that TNFRSF1A levels are dependent on STAT3 function in both constitutive and cytokine-induced models of STAT3 activation. Furthermore, TNFRSF1A is a major mediator of both basal and TNFα-induced NF-κB activity in breast cancer cells. We extended these findings to primary human breast cancers, in which we found that high TNFRSF1A transcript levels correlated with STAT3 activation. In addition, and consistent with a causal role, increased TNFRSF1A expression was associated with an NF-κB gene expression in signature in breast cancers. Thus, TNFRSF1A is a STAT3 target gene that regulates the NF-κB pathway. These findings reveal a novel functional crosstalk between STAT3 and NF-κB signaling in breast cancer. Furthermore, elevated TNFRSF1A levels may predict a subset of breast tumors that are sensitive to STAT3 transcriptional inhibitors, and may be a biomarker for response to inhibition of this pathway.

Folliculin mutation-negative trichodiscomas in a patient with multiple endocine neoplasia type I syndrome.

Mycosis fungoides (MF) is the most common cutaneous T cell lymphoma that involves the oral mucosal. The manifestation of lesions within the oral cavity generally correlates with a poor prognosis. Management of MF includes skin directed therapies and localized radiation treatment, with systemic biologic therapies and chemotherapy used for more advanced stages. The clinical and histologic features of MF in a patient with oral disease are reviewed.

Deregulation of SOCS5 suppresses dendritic cell function in chronic lymphocytic leukemia.

One cause of morbidity and mortality in chronic lymphocytic leukemia (CLL) is infection, which results from defects in a number of components of the immune system. In particular, dendritic cells (DCs) are functionally defective in patients with CLL. To understand the molecular mechanism for this abnormality, we focused on signal transduction pathways that regulate the function of monocyte-derived dendritic cells (Mo-DCs). Monocytes from CLL patients exhibit high IL-4Rα expression due to the enhanced activation of STAT3. However, IL-4R signaling is decoupled from activation of its downstream mediator STAT6 by enhanced levels of the negative regulator SOCS5. This impairs differentiation of functionally mature DCs leading to decreased expression of HLA-DR and costimulatory molecules, and reduced secretion of pro-inflammatory cytokines in LPS-activated DCs. Moreover, Mo-DCs from CLL patients display a decreased ability to induce pro-inflammatory T-cell responses. IL-10-treatment of monocytes from healthy donors mimics the alteration in signaling observed in CLL patients, through enhanced STAT3-dependent expression of SOCS5. The higher level of SOCS5 inhibits STAT6 activation and leads to defective DC differentiation. These findings indicate that SOCS5 mediates the impaired function of DCs in CLL patients, and has the potential to be a new therapeutic target for reversing cancer-associated immune suppression.

STAT3-Interacting Proteins as Modulators of Transcription Factor Function: Implications to Targeted Cancer Therapy.

The oncogenic transcription factor STAT3 is inappropriately activated in multiple hematopoietic and solid malignancies, in which it drives the expression of genes involved in cell proliferation, differentiation, survival, and angiogenesis. Thus far, strategies to inhibit the function of STAT3 have focused on blocking the function of its activating kinases or sequestering its DNA binding ability. A less well-explored aspect of STAT3 function is its interaction with other proteins, which can modulate the oncogenic activity of STAT3 via its subcellular localization, DNA binding ability, and recruitment of transcriptional machinery. Herein we summarize what is currently known about STAT3-interacting proteins and describe the utility of a proteomics-based approach for successfully identifying and characterizing novel STAT3-interacting proteins that affect STAT3 transcriptional activity and oncogenic function.

Impact of the N-Terminal Domain of STAT3 in STAT3-Dependent Transcriptional Activity.

The transcription factor STAT3 is constitutively active in many cancers, where it mediates important biological effects, including cell proliferation, differentiation, survival, and angiogenesis. The N-terminal domain (NTD) of STAT3 performs multiple functions, such as cooperative DNA binding, nuclear translocation, and protein-protein interactions. However, it is unclear which subsets of STAT3 target genes depend on the NTD for transcriptional regulation. To identify such genes, we compared gene expression in STAT3-null mouse embryonic fibroblasts (MEFs) stably expressing wild-type STAT3 or STAT3 from which NTD was deleted. NTD deletion reduced the cytokine-induced expression of specific STAT3 target genes by decreasing STAT3 binding to their regulatory regions. To better understand the potential mechanisms of this effect, we determined the crystal structure of the STAT3 NTD and identified a dimer interface responsible for cooperative DNA binding in vitro. We also observed an Ni(2+)-mediated oligomer with an as yet unknown biological function. Mutations on both dimer and Ni(2+)-mediated interfaces affected the cytokine induction of STAT3 target genes. These studies shed light on the role of the NTD in transcriptional regulation by STAT3 and provide a structural template with which to design STAT3 NTD inhibitors with potential therapeutic value.

Granulin, a novel STAT3-interacting protein, enhances STAT3 transcriptional function and correlates with poorer prognosis in breast cancer.

Since the neoplastic phenotype of a cell is largely driven by aberrant gene expression patterns, increasing attention has been focused on transcription factors that regulate critical mediators of tumorigenesis such as signal transducer and activator of transcription 3 (STAT3). As proteins that interact with STAT3 may be key in addressing how STAT3 contributes to cancer pathogenesis, we took a proteomics approach to identify novel STAT3-interacting proteins. We performed mass spectrometry-based profiling of STAT3-containing complexes from breast cancer cells that have constitutively active STAT3 and are dependent on STAT3 function for survival. We identified granulin (GRN) as a novel STAT3-interacting protein that was necessary for both constitutive and maximal leukemia inhibitory factor (LIF)induced STAT3 transcriptional activity. GRN enhanced STAT3 DNA binding and also increased the time-integrated amount of LIF-induced STAT3 activation in breast cancer cells. Furthermore, silencing GRN neutralized STAT3-mediated tumorigenic phenotypes including viability, clonogenesis, and migratory capacity. In primary breast cancer samples, GRN mRNA levels were positively correlated with STAT3 gene expression signatures and with reduced patient survival. These studies identify GRN as a functionally important STAT3-interacting protein that may serve as an important prognostic biomarker and potential therapeutic target in breast cancer.