Distinct Transcriptional Profiles in the Different Phenotypes of Neurofibroma from the Same Subject with Neurofibromatosis 1

Neurofibromatosis 1 is a prevalent hereditary neurocutaneous disorder. Among the clinical phenotypes of neurofibromatosis 1, cutaneous neurofibroma (cNF) and plexiform neurofibroma (pNF) have distinct clinical manifestations, and pNF should be closely monitored owing to its malignant potential. However, the detailed distinct features of neurofibromatosis 1 phenotypes remain unknown. To determine whether the transcriptional features and microenvironment of cNF and pNF differ, single-cell RNA sequencing was performed on isolated cNF and pNF cells from the same patient. Six cNF and five pNF specimens from different subjects were also immunohistochemically analyzed. Our findings revealed that cNF and pNF had distinct transcriptional profiles even within the same subject. pNF is enriched in Schwann cells with characteristics similar to those of their malignant counterpart, fibroblasts, with a cancer-associated fibroblast-like phenotype, angiogenic endothelial cells, and M2-like macrophages, whereas cNF is enriched in CD8 T cells with tissue residency markers. The results of immunohistochemical analyses performed on different subjects agreed with those of single-cell RNA sequencing. This study found that cNF and pNF, the different neurofibromatosis phenotypes in neurofibromatosis 1, from the same subject are transcriptionally distinct in terms of the cell types involved, including T cells.

Activated Akt expression is associated with the recurrence of primary melanomas and further refines the prognostic and predictive values for relapse in acral melanomas

A PTEN deficiency leads to the activation of phospho-Akt at serine 473 (p-Akt) and promotes the tumorigenesis of melanomas by coupling with NUAK2 amplification. We tested the prognostic impact of p-Akt and/or NUAK2 expression on the relapse-free survival (RFS) and overall survival (OS) of melanoma patients. Primary tumors from patients with acral melanomas (112), Low-cumulative sun damage (CSD) melanomas (38), and High-CSD melanomas (18) were examined using immunohistochemistry and their prognostic significance was analyzed statistically. The expression of p-Akt was found in 32.1%, 68.4%, and 55.6% of acral, Low-CSD, and High-CSD melanomas, while NUAK2 expression was found in 46.4%, 76.3%, and 50.0%, respectively. Either p-Akt or NUAK2 expression was inversely correlated with the RFS of primary melanoma patients and acral melanoma patients (p-Akt: p < .0001, p < .0001; NUAK2; p = .0005, p < .0001, respectively). Strikingly, multivariate analyses revealed that p-Akt had a significant impact on RFS (Hazard ratio = 4.454; p < .0001), while NUAK2 did not. Further subset analyses revealed that p-Akt expression had an inferior RFS of patients with acral melanomas (Hazard ratio = 4.036; p = .0005). We conclude that the expression of p-Akt has a significant impact on RFS of patients with primary melanomas and can predict the relapse of patients with acral melanomas.

Gap junction-mediated contraction of myoepithelial cells induces the peristaltic transport of sweat in human eccrine glands

Eccrine sweat glands play an essential role in regulating body temperature. Sweat is produced in the coiled secretory portion of the gland, which is surrounded by obliquely aligned myoepithelial cells; the sweat is then peristaltically transported to the skin surface. Myoepithelial cells are contractile and have been implicated in sweat transport, but how myoepithelial cells contract and transport sweat remains unexplored. Here, we perform ex vivo live imaging of an isolated human eccrine gland and demonstrate that cholinergic stimulation induces dynamic contractile motion of the coiled secretory duct that is driven by gap junction-mediated contraction of myoepithelial cells. The contraction of the secretory duct occurs segmentally, and it is most prominent in the region surrounded by nerve fibers, followed by distension-contraction sequences of the excretory duct. Overall, our ex vivo live imaging approach provides evidence of the contractile function of myoepithelial cells in peristaltic sweat secretion from human eccrine glands.

Worldwide expert recommendations for the diagnosis and management of vitiligo: Position statement from the International Vitiligo Task Force Part 1: towards a new management algorithm

BACKGROUND

The treatment of vitiligo can be challenging and depends on several factors such as the subtype, disease activity, vitiligo extent, and treatment goals. Vitiligo usually requires a long-term approach. To improve the management of vitiligo worldwide, a clear and up-to-date guide based on international consensus with uniform stepwise recommendations is needed.

OBJECTIVES

To reach an international consensus on the nomenclature and to develop a management algorithm for the diagnosis, assessment, and treatment of vitiligo.

METHODS

In this consensus statement, a consortium of 42 international vitiligo experts and four patient representatives participated in online and live meetings to develop a consensus management strategy for vitiligo. At least two vitiligo experts summarized the evidence of topics included in the algorithms. A survey was utilized to resolve remaining issues among a core group of eight experts. Subsequently, the unanimous recommendations were finalized and validated based on further input from the entire group during two live meetings.

RESULTS

The algorithms highlight the importance of shared decision-making. Dermatologists are encouraged to provide patients with detailed explanations of the prognosis and expected therapeutic outcomes based on clinical examination. The treatment goal should be discussed and clearly emphasized to patients given the different approaches for disease stabilization and repigmentation. The evaluation of disease activity remains a cornerstone in the tailor-made approach to vitiligo patients.

CONCLUSIONS

These new treatment algorithms are intended to guide clinical decision-making in clinical practice. Promising novel therapies for vitiligo are on the horizon, further highlighting the need for reliable outcome measurement instruments and greater emphasis on shared decision-making.

Worldwide expert recommendations for the diagnosis and management of vitiligo: Position statement from the international Vitiligo Task Force-Part 2: Specific treatment recommendations

BACKGROUND

The treatment of vitiligo can be challenging. Up-to-date agreed consensus recommendations on the use of topical and systemic therapies to facilitate the clinical management of vitiligo are currently lacking.

OBJECTIVES

To develop internationally agreed-upon expert-based recommendations for the treatment of vitiligo.

METHODS

In this consensus statement, a consortium of 42 international vitiligo experts and four patient representatives participated in different online and live meetings to develop a consensus management strategy for vitiligo. At least two vitiligo experts summarized the evidence for different topics included in the algorithms. A survey was then given to a core group of eight experts to resolve the remaining issues. Subsequently, the recommendations were finalized and validated based on further input from the entire group during two live meetings.

RESULTS

The recommendations provided summarize the latest evidence regarding the use of topical therapies (steroids, calcineurin inhibitors and Jak-inhibitors) and systemic therapies, including steroids and other systemic immunomodulating or antioxidant agents. The different modalities of phototherapies (NB-UVB, photochemotherapy, excimer devices and home phototherapy), which are often combined with other therapies, are also summarized. Interventional approaches as well as depigmentation strategies are presented for specific indications. Finally, the status of innovative and targeted therapies under development is discussed.

CONCLUSIONS

This international consensus statement culminated in expert-based clinical practice recommendations for the treatment of vitiligo. The development of new therapies is ongoing in vitiligo, and this will likely improve the future management of vitiligo, a disease that still has many unmet needs.

GREB1 isoform 4 is specifically transcribed by MITF and required for melanoma proliferation

Growth regulation by estrogen in breast cancer 1 (GREB1) is involved in hormone-dependent and -independent tumor development (e.g., hepatoblastoma). In this study, we found that a GREB1 splicing variant, isoform 4 (Is4), which encodes C-terminal half of full-length GREB1, is specifically expressed via microphthalmia-associated transcription factor (MITF) in melanocytic melanoma, and that two MITF-binding E-box CANNTG motifs at the 5'-upstream region of GREB1 exon 19 are necessary for GREB1 Is4 transcription. MITF and GREB1 Is4 were strongly co-expressed in approximately 20% of the melanoma specimens evaluated (17/89 cases) and their expression was associated with tumor thickness. GREB1 Is4 silencing reduced melanoma cell proliferation in association with altered expression of cell proliferation-related genes in vitro. In addition, GREB1 Is4 targeting by antisense oligonucleotide (ASO) decreased melanoma xenograft tumor formation and GREB1 Is4 expression in a BRAFV600E; PTENflox melanoma mouse model promoted melanoma formation, demonstrating the crucial role of GREB1 Is4 for melanoma proliferation in vivo. GREB1 Is4 bound to CAD, the rate-limiting enzyme of pyrimidine metabolism, and metabolic flux analysis revealed that GREBI Is4 is necessary for pyrimidine synthesis. These results suggest that MITF-dependent GREB1 Is4 expression leads to melanoma proliferation and GREB1 Is4 represents a new molecular target in melanoma.

Understanding of Pathomechanisms and Clinical Practice for Vitiligo

Vitiligo is a disease caused by the acquired depletion of melanocytes and/or melanocyte precursor cells in response to genetic and environmental factors, resulting in depigmentation of the entire body. It is roughly divided into segmental and non-segmental vitiligo, and it has been found that abnormalities of melanocytes themselves and dysregulation of autoimmune responses to melanocytes are greatly involved in the pathology of non-segmental vitiligo. Segmental vitiligo pathology is largely unknown; however, it has been suggested that it may be caused by skin or melanocyte mosaicism. Treatments for vitiligo include topical therapy, ultraviolet therapy, and surgical transplantation, and it is extremely important to correctly understand the pathology to perform optimal treatment. In recent years, the development of vitiligo treatments using Janus kinase (JAK) inhibitors has progressed rapidly. We herein outline the latest pathology of vitiligo, from general vitiligo treatment to the progress of clinical trials using JAK inhibitors, along with what clinicians should consider in archiving precision medicine, including my own ideas thereon.

Trousseau Syndrome in a Case of Extramammary Paget's Disease

Abstract is missing (Short communication)

Increased anti-oxidative action compensates for collagen tissue degeneration in vitiligo dermis

Vitiligo is a common depigmentation disorder characterized by the selective loss of melanocytes. In our daily clinic experience, we noticed that the skin tightness of hypopigmented lesions would be more evident in comparison to that of uninvolved perilesional skin in vitiligo patients. Therefore, we hypothesized that collagen homeostasis might be maintained in vitiligo lesions, irrespective of the substantial excessive oxidative stress that occurs in association with the disease. We found that the expression levels of collagen-related genes and anti-oxidative enzymes were upregulated in vitiligo-derived fibroblasts. Abundant collagenous fibers were observed in the papillary dermis of vitiligo lesions in comparison to uninvolved perilesional skin by electron microscopy. The production of matrix metalloproteinases that degraded collagen fibers was suppressed. The deposition of acrolein adduct protein, which is a product of oxidative stress, was significantly reduced in vitiligo dermis and fibroblasts. As part of the mechanism, we found upregulation of the NRF2 signaling pathway activity, which is an important defense system against oxidative stress. Taken together, we demonstrated that the anti-oxidative action and collagen production were upregulated and that the collagen degeneration was attenuated in vitiligo dermis. These new findings may provide important clues for the maintenance of antioxidant ability in vitiligo lesions.

c-FOS Expression in Metastatic Basal Cell Carcinoma with Spontaneous Basosquamous Transition

Abstract is missing (Short communication)

Basal cell carcinoma of the umbilicus associated with sweat gland structures: Two case reports

RATIONALE

Basal cell carcinoma (BCC) arising in the umbilicus is relatively rare, and in particular, there have been few reports mentioning peritumoral sweat gland structures histopathologically. We herein, report 2 cases of umbilical BCC with sweat gland structures within and around the tumor.

PATIENT CONCERNS

A 61-year-old woman had a 2-year history of black exudative plaque in her umbilicus, and an 80-year-old woman had a 6-month history of dark brownish plaque in the umbilicus, with exudation 2 months prior to her first visit.

DIAGNOSES

Based on the histopathological finding, both cases were confirmed as BCC. The results of immunohistochemical staining showed that the tumor cells were Ber-EP4 positive. In addition, EMA-positive glandular structures were seen within and around the tumor.

INTERVENTIONS

Curative resection at the level of the linea alba on the bottom side was performed.

OUTCOMES

No relapse has been observed since resection in either patient.

LESSONS

We herein report 2 cases of umbilical BCC with sweat glands and ducts. Although whether peri- and/or intra-tumor sweat gland structures are the source of the tumor or arise by transdifferentiation from tumor cells remains unclear, these findings may provide clues to help understand the morphopathogenesis of umbilical BCC in the future.

Aggressive Squamous Cell Carcinoma in a Case of Epidermodysplasia Verruciformis Carrying a TMC6 Splice-site Mutation

Abstract is missing (Short communication)

WT1 Trio Peptide-Based Cancer Vaccine for Rare Cancers Expressing Shared Target WT1

No standard treatment has been established for most rare cancers. Here, we report a clinical trial of a biweekly WT1 tri-peptide-based vaccine for recurrent or advanced rare cancers. Due to the insufficient number of patients available for a traditional clinical trial, the trial was designed for rare cancers expressing shared target molecule WT1. The recruitment criteria included WT1-expressing tumors as well as HLA-A*24:02 or 02:01. The primary endpoints were immunoglobulin G (IgG) antibody (Ab) production against the WT1-235 cytotoxic T lymphocyte (CTL) epitope and delayed-type hypersensitivity (DTH) skin reactions to targeted WT1 CTL epitopes. The secondary endpoints were safety and clinical efficacy. Forty-five patients received WT1 Trio, and 25 (55.6%) completed the 3-month protocol treatment. WT1-235 IgG Ab was positive in 88.0% of patients treated with WT1 Trio at 3 months, significantly higher than 62.5% of the weekly WT1-235 CTL peptide vaccine. The DTH positivity rate in WT1 Trio was 62.9%, which was not significantly different from 60.7% in the WT1-235 CTL peptide vaccine. The WT1 Trio safety was confirmed without severe treatment-related adverse events, except grade 3 myasthenia gravis-like symptoms observed in a patient with thymic cancer. Fifteen (33.3%) patients achieved stable disease after 3 months of treatment. In conclusion, the biweekly WT1 Trio vaccine containing the WT1-332 helper T lymphocyte peptide induced more robust immune responses targeting WT1 than the weekly WT1-235 CTL peptide vaccine. Therefore, WT1-targeted immunotherapy may be a potential therapeutic strategy for rare cancers.

Melanocyte-specific CD49a+ CD8+ T cells in vitiligo lesion potentiate to maintain activity during systemic steroid therapy

Vitiligo is a common depigmenting skin disease that is often difficult to treat. Even if repigmentation is achieved by treatment, recurrence in the same lesion is often found within a year after stopping treatment. As a background of these issues, a subset of CD8⁺ T cells that recognize melanocyte-specific antigens or CD49a⁺ tissue-resident memory T cells that reside in the vitiligo lesion are thought to be involved. We investigated the MHC class I-restricted tyrosinase pentamer-positive CD8⁺ skin T cells in a progressive generalized vitiligo patient with HLA-A*02:01 who showed resistance to intravenous methylprednisolone pulse therapy. We found that HLA-A*02:01-restricted tyrosinase pentamer-positive CD8⁺ T cells remained in the lesions after the treatment and expressed IFN-γ and granzyme B. Interestingly, the expression of these cytokines in the pentamer-negative CD8⁺ T cells was decreased after intravenous methylprednisolone pulse therapy. These findings suggest that, in vitiligo patients, melanocyte-specific CD49a⁺ CD8⁺ T cells are in a potent activation state that is uncontrolled despite systemic immunosuppressive treatment, which may contribute to treatment resistance and local recurrence.

Nivolumab-induced systemic lymphadenopathy occurring during treatment of malignant melanoma: a case report

Nivolumab is an anti-programmed cell death protein 1 monoclonal antibody that exhibits significant efficacy in treating melanoma and other malignancies. However, various nivolumab-induced immune-related adverse events (irAEs) have been reported, and differentiating irAEs from tumor progression is sometimes difficult. Here, we report a case of reactive lymphadenopathy occurring after treatment with nivolumab. A 56-year-old man with stage IIIC melanoma received adjuvant therapy with nivolumab after wide local excision. He developed systemic lymphadenopathy and autoimmune hemolytic anemia 1 month after receiving seven cycles of nivolumab. Pathological analysis of a cervical lymph node biopsy specimen revealed no metastatic lesion or any other malignancy, including lymphoma. Thus, the patient was diagnosed with nivolumab-induced reactive lymphadenopathy. Systemic corticosteroids were administered to reduce hemolysis, which led to the resolution of lymphadenopathy. When progressive lymphadenopathy is observed in a patient who received immune checkpoint inhibitor therapy, reactive lymphadenopathy should be carefully distinguished from progression to lymphoid metastasis, and biopsy should be performed if needed.

A phase I dose-escalation, safety/tolerability, and preliminary efficacy study of the intratumoral administration of GEN0101 in patients with advanced melanoma

Despite recent advance in immunotherapy agents, safe new therapies that enhance the effects of immune checkpoint inhibitors are still required to develop. We previously demonstrated that hemagglutinating virus of Japan-envelope (HVJ-E) induced not only direct tumor cell death but also antitumor immunity through the activation of T and natural killer (NK) cells, thereafter, developed a manufacturing process of HVJ-E (GEN0101) for clinical use. We here performed a phase Ia clinical trial of intratumoral GEN0101 administration in six patients with stage IIIC or IV malignant melanoma. The primary aim was to evaluate the safety and tolerability of GEN0101, and the secondary aim was to examine the objective tumor response. Patients were separated into two groups (n = 3 each) and received a low dose of 30,000 and high dose of 60,000 mNAU of GEN0101. All patients completed a two-week follow-up evaluation without severe adverse events. The overall response rate was 33% (2 of 6), with 2 partial responses in the high-dose group and 2 with stable disease, and 2 with progressive disease in the low-dose group. Local complete or partial responses were observed in 11 of 18 (61%) target lesions. One patient demonstrated shrinkage of lung metastases after the treatment. The activity of NK cells and interferon-γ levels were increased in the circulation, indicating augmentation of antitumor immunity by GEN0101. This trial showed not only the safety and tolerability but also the significant antitumor effect of GEN0101, suggesting that GEN0101 might be a promising new drug for patients with advanced melanoma.

Tumor response evaluation in patients with malignant melanoma undergoing immune checkpoint inhibitor therapy and prognosis prediction using 18F-FDG PET/CT: multicenter study for comparison of EORTC, PERCIST, and imPERCIST

OBJECTIVE

In malignant melanoma patients treated with immune checkpoint inhibitor (ICI) therapy, three different FDG-PET criteria, European Organization for Research and Treatment of Cancer (EORTC), PET Response Criteria in Solid Tumors (PERCIST), immunotherapy-modified PERCIST (imPERCIST), were compared regarding response evaluation and prognosis prediction using standardized uptake value (SUV) harmonization of results obtained with various PET/CT scanners installed at different centers.

MATERIALS AND METHODS

Malignant melanoma patients (n = 27) underwent FDG-PET/CT examinations before and again 3 to 9 months after therapy initiation (nivolumab, n = 21; pembrolizumab, n = 6) with different PET scanners at five hospitals. EORTC, PERCIST, and imPERCIST criteria were used to evaluate therapeutic response, then concordance of the results was assessed using Cohen's κ coefficient. Log-rank and Cox methods were employed to determine progression-free (PFS) and overall (OS) survival.

RESULTS

Complete metabolic response (CMR)/partial metabolic response (PMR)/stable metabolic disease (SMD)/progressive metabolic disease (PMD) with harmonized EORTC, PERCIST, and imPERCIST was seen in 3/5/4/15, 4/5/3/15, and 4/5/5/13 patients, respectively. Nearly perfect concordance between each pair of criteria was noted (κ = 0.939-0.972). Twenty patients showed progression and 14 died from malignant melanoma after a median 19.2 months. Responders (CMR/PMR) showed significantly longer PFS and OS than non-responders (SMD/PMD) (harmonized EORTC: p < 0.0001 and p = 0.011; harmonized PERCIST: p < 0.0001 and p = 0.0012; harmonized imPERCIST: p < 0.0001 and p = 0.0012, respectively).

CONCLUSIONS

All harmonized FDG-PET criteria (EORTC, PERCIST, imPERCIST) showed accuracy for response evaluation of ICI therapy and prediction of malignant melanoma patient prognosis. Additional studies to determine their value in larger study populations will be necessary.

Abstract 1847: Anti-GARP antibody DS-1055a augments antitumor immunity by depleting highly suppressive GARP+ regulatory T cells

Immune checkpoint blockers (ICBs) have drastically changed the clinical care of cancer; however, the population of patients who can benefit is relatively small because of intrinsic or acquired resistance to immune therapy. To evade immune destruction, tumors exploit several distinct strategies including immunosuppressive cells such as regulatory T (Treg) cells. Treg cells, an essential component for maintaining self-tolerance, inhibit antitumor immunity, consequently hindering protective cancer immunosurveillance and hampering effective antitumor immune responses in tumor-bearing hosts. It is often reported that a high ratio of Treg cells to effector CD8+ T cells is associated with poor prognosis in patients with cancer, and Treg cells represent one of the most important factors associated with resistance to ICBs, suggesting that Treg cells represent a new promising target for anti-cancer therapy. In this study, we performed a comprehensive screening to identify a tumor-infiltrating Treg cell-specific molecule among immune cell subsets in humans. Glycoprotein A repetitions predominant (GARP) was identified as a suitable target for selective Treg cell depletion in the tumor microenvironment (TME) of multiple caner types. In the periphery, GARP was selectively induced in Treg cells, but not in effector T cells, by polyclonal stimulation in humans. DS-1055a, a novel afucosylated anti-human GARP antibody, effectively depleted GARP+ Treg cells, leading to the activation of effector T cells. Moreover, DS-1055a decreased FOXP3+CD4+ T cell counts in the TME and exhibited remarkable antitumor activity in a human peripheral blood mononuclear cell-transplanted humanized mouse model bearing HT-29 tumors. From these results, we propose that DS-1055a can be a new Treg cell-targeted regent that augments antitumor T cell immunity by depleting GARP+ Treg cells. Currently, a Phase I study of DS-1055a is on-going (NCT04419532).

Citation Format: Kazuki Satoh, Yoichi Kobayashi, Kaori Fujimaki, Masato Hata, Shinko Hayashi, Saori Ishida, Daisuke Sugiyama, Takahiko Sato, Lim Kyungtaek, Megumi Miyamoto, Shiho Kozuma, Michinori Kadokura, Kenichi Wakita, Kazuki Hirahara, Masato Amano, Ichiro Watanabe, Atsushi Okamoto, Andrea Tuettenberg, Helmut Jonuleit, Atsushi Tanemura, Shoichi Maruyama, Toshinori Agatsuma, Teiji Wada, Hiroyoshi Nishikawa. Anti-GARP antibody DS-1055a augments antitumor immunity by depleting highly suppressive GARP+ regulatory T cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1847.

Novel anti-GARP antibody DS-1055a augments anti-tumor immunity by depleting highly suppressive GARP+ regulatory T cells

Regulatory T (Treg) cells, which are essential for maintaining self-tolerance, inhibit anti-tumor immunity, consequently hindering protective cancer immunosurveillance, and hampering effective anti-tumor immune responses in tumor-bearing hosts. Here, we show that depletion of Treg cells via targeting glycoprotein A repetitions predominant (GARP) induces effective anti-tumor immune responses. GARP was specifically expressed by highly suppressive Treg cells in the tumor microenvironment (TME) of multiple cancer types in humans. In the periphery, GARP was selectively induced in Treg cells, but not in effector T cells, by polyclonal stimulation. DS-1055a, a novel afucosylated anti-human GARP monoclonal antibody, efficiently depleted GARP+ Treg cells, leading to the activation of effector T cells. Moreover, DS-1055a decreased FoxP3+CD4+ T cells in the TME and exhibited remarkable anti-tumor activity in humanized mice bearing HT-29 tumors. We propose that DS-1055a is a new Treg-cell-targeted cancer immunotherapy agent with augmentation of anti-tumor immunity.

Rhododendrol-induced leukoderma update II: Pathophysiology, mechanisms, risk evaluation, and possible mechanism-based treatments in comparison with vitiligo

A small proportion of individuals utilizing cosmetics containing rhododendrol developed leukoderma with various pathological conditions, in some cases indistinguishable from vitiligo. In this review, we investigate and evaluate the major considerations for developing rhododendrol‐induced leukoderma based on data from original or review articles published in the literature to provide a wide range of information regarding the pathophysiology, mechanisms, risk evaluation, and possible mechanism‐based treatments. We compile and discuss the latest information, including data related to the cytotoxicity of rhododendrol, cytoprotective functions, and involvement of the immune system, and consider the possibility of novel treatments based on the differences between individual patients and on the mechanism underlying the onset of the condition. Understanding the pathophysiology of rhododendrol‐induced leukoderma helps not only elucidate the mechanisms of non‐segmental vitiligo onset and progression, but also suggests prevention and treatment.

Ganglioside GD3 May Suppress the Functional Activities of Benign Skin T Cells in Cutaneous T-Cell Lymphoma

In cutaneous T-cell lymphoma (CTCL), which arises from skin-tropic memory T cells, malignant T cells and benign T cells are confined in the same skin lesions. It is thus difficult to evaluate the phenotypic characteristics and functional activities of benign T cells in CTCL. Disialoganglioside with three glycosyl groups (GD3) is increasingly expressed on the surface of solid malignant tumor cells and takes part in tumor progression and suppression of tumor immunity. However, the role of GD3 in CTCL is not well-understood. In this study, the malignant and benign T cells in CTCL skin lesions were distinguished by flow cytometry and their phenotypic characteristics were compared with those of T cells from control skin specimens. In CTCL skin lesions, the benign T cells included limited resident memory T cells (T_RM), which are sessile in skin and known to exert strong antitumor function. The benign T cells showed diminished Th17 property, and the expression of GD3 was high in the malignant T cells. The expression of GD3 in the malignant T cells inversely correlated with IL-17A production from the benign CD4 T cells. GD3 from the malignant T cells was implied to be involved in suppressing the Th17 activity of the benign T cells independent of the regulation of T_RM differentiation in CTCL. Revealing the role of GD3 in inhibiting the production of IL-17A in CTCL would aid the understanding of the suppressive mechanism of the antitumor activity by malignant tumor cells.

Cutaneous Squamous Cell Carcinoma in the Age of Immunotherapy

Cutaneous squamous cell carcinoma (cSCC) is the second most prevalent skin cancer globally. Because most cSCC cases are manageable by local excision/radiotherapy and hardly become life-threatening, they are often excluded from cancer registries in most countries. Compared with cutaneous melanoma that originates from the melanin-producing, neural crest-derived epidermal resident, keratinocyte (KC)-derived cancers are influenced by the immune system with regards to their pathogenetic behaviour. Congenital or acquired immunosurveillance impairments compromise tumoricidal activity and raises cSCC incidence rates. Intriguingly, expanded applications of programmed death-1 (PD-1) blockade therapies have revealed cSCC to be one of the most amenable targets, particularly when compared with the mucosal counterparts arisen in the esophagus or the cervix. The clinical observation reminds us that cutaneous tissue has a peculiarly high immunogenicity that can evoke tumoricidal recall responses topically. Here we attempt to redefine cSCC biology and review current knowledge about cSCC from multiple viewpoints that involve epidemiology, clinicopathology, molecular genetics, molecular immunology, and developmental biology. This synthesis not only underscores the primal importance of the immune system, rather than just a mere accumulation of ultraviolet-induced mutations but also reinforces the following hypothesis: PD-1 blockade effectively restores the immunity specially allowed to exist within the fully cornified squamous epithelium, that is, the epidermis.

Rhododendrol-induced leukoderma update I: Clinical findings and treatment

Individuals who used skin-whitening cosmetics (quasi-drugs) containing 2% rhododendrol-containing agents, developed leukoderma at a higher frequency than those who have used other skin-whitening cosmetics. The Rhododenol Research Team (RD-Team) was formed and commissioned by Kanebo Cosmetics Inc. to conduct research in treatments of rhododendrol-induced leukoderma (RDL), to evaluate effective treatment options from a medical standpoint, and provide information to a wide range of people. In this study, we evaluated the efficacy of various treatments for RDL from a medical perspective, based on the information published in the literature as original or review articles. We searched the PubMed (international) and the Igaku Chuo Zasshi (ICHUSHI) (Japanese) databases using the keywords "Rhododenol" and "rhododendrol", for articles published between July 2013 and November 2020. We discuss the main clinical findings and treatments (topical, oral, phototherapy, and surgical) of this condition based on the literature review. We found that ultraviolet light therapy is the most effective treatment for RDL. We have also summarized reports of the efficacy of oral vitamin D3 in RDL. A topical prostaglandin derivative has been reported in a new study to be effective. We have provided guidance for patients using self-tanning and skin-whitening agents to improve their quality of life. Finally, we have highlighted the importance of providing patients with information on contact dermatitis and instructing them to discontinue product use immediately if they develop any symptoms of contact dermatitis while using skin-whitening agents.

A case report of anal canal cancer with pagetoid spread requiring differential diagnosis

INTRODUCTION

Paget's disease is an intraepithelial invasion by a malignant tumour and is characterised by erythema and inflammation. It can manifest as mammary or extramammary Paget's disease (EMPD), with the latter often developing in the perianal area. Anorectal cancer can cause transepithelial invasion into the epidermis, resulting in an appearance similar to that of EMPD. This is called pagetoid spread (PS), which is completely different from EMPD. These two conditions are difficult to differentiate because of the nature of intricacy and requirements of histopathology.

PRESENTATION OF CASE

We present a case in which differential diagnosis between these two conditions was not possible during the preoperative examination, resulting in difficulties in treatment. The patient was a 70-year-old woman who experienced pain in the anus since the previous month and presented with red, flat and elevated lesions.

DISCUSSION

Treatment for dermatitis was ineffective, and endoscopic examination did not indicate rectal or anal cancer. However, immunohistochemical examination of the biopsy specimen suggested PS. Thus, two-stage operation was planned. Transanal surgery was performed to confirm the diagnosis of PS and intersphincteric resection was allowed as a radical surgery.

CONCLUSION

Thus, when differentiation between EMPD and PS is intricacy, two-stage operation is useful in selecting an appropriate radical surgery method, leading to preservation of anal function.

Genome-wide association study identifies CDH13 as a susceptibility gene for rhododendrol-induced leukoderma

Racemic RS-4-(4-hydroxyphenyl)-2-butanol (rhododendrol; trade name: Rhododenol [RD]), which is used in topical skin-lightening cosmetics, was unexpectedly reported in Japan to induce leukoderma or vitiligo called RD-induced leukoderma (RIL) after repeated application. To our knowledge, no studies have investigated chemical-induced vitiligo pathogenesis on a genome-wide scale. Here, we conducted a genome-wide association study (GWAS) for 147 cases and 112 controls. CDH13, encoding a glycosylphosphatidylinositol-anchored protein called T-cadherin (T-cad), was identified as the strongest RIL susceptibility gene. RD sensitivity was remarkably increased by T-cad knockdown in cultured normal human melanocytes. Furthermore, we confirmed tyrosinase upregulation and downregulation of the anti-apoptotic molecules (BCL-2 and BCL-XL), suggesting that T-cad is associated with RD via tyrosinase or apoptotic pathway regulation. Finally, monobenzyl ether of hydroquinone sensitivity also tended to increase with T-cad knockdown, suggesting that the T-cad could be a candidate susceptibility gene for RIL and other chemical-induced vitiligo forms. This is the first GWAS for chemical-induced vitiligo, and it could be a useful model for studying the disease's genetic aspects.

Intratumoral injection of hemagglutinating virus of Japan-envelope vector yielded an antitumor effect for advanced melanoma: a phase I/IIa clinical study

Hemagglutinating virus of Japan (HVJ; Sendai virus) is an RNA virus that has cell fusion activity. HVJ-envelope (HVJ-E) is a UV-irradiated HVJ particle that loses viral replication and protein synthesis activity but retains cell fusion activity. We recently reported that HVJ-E has antitumor effects on several types of tumors. Here, we describe the results of a first-in-human phase I/IIa study in patients with advanced melanoma, receiving intratumoral administration of HVJ-E. The primary aim was to evaluate the safety and tolerability of HVJ-E, and the secondary aim was to examine the objective tumor response and antitumor immunity. Six patients with stage IIIC or IV progressive malignant melanoma with skin or lymph metastasis were enrolled. Patients were separated into two groups (n = 3 each) and received low and high doses of HVJ-E. Five of the six patients completed 4 weeks of follow-up evaluation; one patient discontinued treatment owing to progressive disease. Complete or partial responses were observed in 3 of 6 (50%) injected target lesions, 7 of 15 (47%) noninjected target lesions, and 10 of 21 (48%) target lesions. Induction of antitumor immunity was observed: activation of natural killer cells, a marked increase in interferon-γ levels in the peripheral blood, and infiltration of cytotoxic T cells into both injected and noninjected tumor lesions. Thus, intratumoral injection of HVJ-E in advanced melanoma patients showed safety and tolerability with local regression of the tumor mediated by antitumor immunity. The results suggest that HVJ-E might be a new treatment approach in patients with advanced melanoma.