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.

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.

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.

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.

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.

Inhibiting STAT5 by the BET bromodomain inhibitor JQ1 disrupts human dendritic cell maturation.

Maturation of dendritic cells (DCs) is required to induce T cell immunity, whereas immature DCs can induce immune tolerance. Although the transcription factor STAT5 is suggested to participate in DC maturation, its role in this process remains unclear. In this study, we investigated the effect of STAT5 inhibition on LPS-induced maturation of human monocyte-derived DCs (Mo-DCs). We inhibited STAT5 by treating Mo-DCs with JQ1, a selective inhibitor of BET epigenetic readers, which can suppress STAT5 function. We found that JQ1 inhibits LPS-induced STAT5 phosphorylation and nuclear accumulation, thereby attenuating its transcriptional activity in Mo-DCs. The diminished STAT5 activity results in impaired maturation of Mo-DCs, as indicated by defective upregulation of costimulatory molecules and CD83, as well as reduced secretion of IL-12p70. Expression of constitutively activated STAT5 in JQ1-treated Mo-DCs overcomes the effects of JQ1 and enhances the expression of CD86, CD83, and IL-12. The activation of STAT5 in Mo-DCs is mediated by GM-CSF produced following LPS stimulation. Activated STAT5 then leads to increased expression of both GM-CSF and GM-CSFR, triggering an autocrine loop that further enhances STAT5 signaling and enabling Mo-DCs to acquire a more mature phenotype. JQ1 decreases the ability of Mo-DCs to induce allogeneic CD4(+) and CD8(+) T cell proliferation and production of proinflammatory cytokines. Furthermore, JQ1 leads to a reduced generation of inflammatory CD8(+) T cells and decreased Th1 differentiation. Thus, JQ1 impairs LPS-induced Mo-DC maturation by inhibiting STAT5 activity, thereby generating cells that can only weakly stimulate an adaptive-immune response. Therefore, JQ1 could have beneficial effects in treating T cell-mediated inflammatory diseases.

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.

Multi-genetic events collaboratively contribute to Pten-null leukaemia stem-cell formation.

Cancer stem cells, which share many common properties and regulatory machineries with normal stem cells, have recently been proposed to be responsible for tumorigenesis and to contribute to cancer resistance. The main challenges in cancer biology are to identify cancer stem cells and to define the molecular events required for transforming normal cells to cancer stem cells. Here we show that Pten deletion in mouse haematopoietic stem cells leads to a myeloproliferative disorder, followed by acute T-lymphoblastic leukaemia (T-ALL). Self-renewable leukaemia stem cells (LSCs) are enriched in the c-Kit(mid)CD3(+)Lin(-) compartment, where unphosphorylated beta-catenin is significantly increased. Conditional ablation of one allele of the beta-catenin gene substantially decreases the incidence and delays the occurrence of T-ALL caused by Pten loss, indicating that activation of the beta-catenin pathway may contribute to the formation or expansion of the LSC population. Moreover, a recurring chromosomal translocation, T(14;15), results in aberrant overexpression of the c-myc oncogene in c-Kit(mid)CD3(+)Lin(-) LSCs and CD3(+) leukaemic blasts, recapitulating a subset of human T-ALL. No alterations in Notch1 signalling are detected in this model, suggesting that Pten inactivation and c-myc overexpression may substitute functionally for Notch1 abnormalities, leading to T-ALL development. Our study indicates that multiple genetic or molecular alterations contribute cooperatively to LSC transformation.

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.

Targeting transcription factors: promising new strategies for cancer therapy.

PURPOSE OF REVIEW: A lack of effective treatments for advanced cancer remains a major challenge in oncology. Because cancer is a disease associated with aberrant gene expression patterns, transcription factors, which serve as the convergence points of oncogenic signaling and are functionally altered in many cancers, hold great therapeutic promise. RECENT FINDINGS: Many human cancers are dependent on the inappropriate activity of oncogenic transcription factors. By contrast, normal cells can often tolerate disruption of these proteins with little toxicity. Direct inhibition of transcription factor expression (e.g., with RNA interference or microRNAs) and DNA binding (e.g., with oligodeoxynucleotide decoys or pyrrole-imidazole polyamides) has demonstrated antitumor responses with minimal side-effects. New strategies of targeting transcription factors include disrupting critical protein-protein interactions, and restricting binding at the epigenetic level by modulating chromatin accessibility. Moreover, targeting transcription factors in tumor-associated immune cells has the potential to overcome tumor immunoresistance. SUMMARY: Transcription factors are an important target for cancer therapy, both through direct anticancer effects and immunomodulatory actions. Newly developed delivery systems that specifically target tumor cells also create opportunities for successes in targeting transcription in cancer.

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.

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.

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.

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.