The aryl hydrocarbon receptor AhR links atopic dermatitis and air pollution via induction of the neurotrophic factor artemin.

Atopic dermatitis is increasing worldwide in correlation with air pollution. Various organic components of pollutants activate the transcription factor AhR (aryl hydrocarbon receptor). Through the use of AhR-CA mice, whose keratinocytes express constitutively active AhR and that develop atopic-dermatitis-like phenotypes, we identified Artn as a keratinocyte-specific AhR target gene whose product (the neurotrophic factor artemin) was responsible for epidermal hyper-innervation that led to hypersensitivity to pruritus. The activation of AhR via air pollutants induced expression of artemin, alloknesis, epidermal hyper-innervation and inflammation. AhR activation and ARTN expression were positively correlated in the epidermis of patients with atopic dermatitis. Thus, AhR in keratinocytes senses environmental stimuli and elicits an atopic-dermatitis pathology. We propose a mechanism of air-pollution-induced atopic dermatitis via activation of AhR.

Tumor eradication by triplet therapy with BRAF inhibitor, TLR 7 agonist, and PD-1 antibody for BRAF-mutated melanoma.

Programmed death 1 (PD-1)/programmed death-ligand 1 inhibitors are commonly used to treat various cancers, including melanoma. However, their efficacy as monotherapy is limited, and combination immunotherapies are being explored to improve outcomes. In this study, we investigated a combination immunotherapy involving an anti-PD-1 antibody that blocks the major adaptive immune-resistant mechanisms, a BRAF inhibitor that inhibits melanoma cell proliferation, and multiple primary immune-resistant mechanisms, such as cancer cell-derived immunosuppressive cytokines, and a Toll-like receptor 7 agonist that enhances innate immune responses that promote antitumor T-cell induction and functions. Using a xenogeneic nude mouse model implanted with human BRAF-mutated melanoma, a BRAF inhibitor vemurafenib was found to restore T-cell-stimulatory activity in conventional dendritic cells by reducing immunosuppressive cytokines, including interleukin 6, produced by human melanoma. Additionally, intravenous administration of the Toll-like receptor 7 agonist DSR6434 enhanced tumor growth inhibition by vemurafenib through stimulating the plasmacytoid dendritic cells/interferon-α/natural killer cell pathways and augmenting the T-cell-stimulatory activity of conventional dendritic cells. In a syngeneic mouse model implanted with murine BRAF-mutated melanoma, the vemurafenib and DSR6434 combination synergistically augmented the induction of melanoma antigen gp100-specific T cells and inhibited tumor growth. Notably, only triplet therapy with vemurafenib, DSR6434, and the anti-PD-1 antibody resulted in complete regression of SIY antigen-transduced BRAF-mutated melanoma in a CD8 T-cell-dependent manner. These findings indicate that a triple-combination strategy targeting adaptive and primary resistant mechanisms while enhancing innate immune responses that promote tumor-specific T cells may be crucial for effective tumor eradication.

Persistent alteration of the skin microbiome in patients with skin rash after receiving EGFR inhibitor treatment.

The pathological mechanism responsible for EGFR inhibitor (EGFRI)-induced skin rash remains unclear. Recent studies reveal associations between skin dysbiosis and skin inflammatory diseases. This study aimed to examine whether skin dysbiosis is associated with EGFRI-induced skin rash. Bacterial swabs were taken from the forehead of 17 cancer patients at baseline and at several time points after EGFRIs initiation, as well as from 20 healthy controls. The skin microbiome was analysed using 16S rRNA sequencing. The severity of the skin rash was assessed using the rash grade. Skin surface parameters (pH, water capacitance, and sebum level) were also measured. Compared with baseline, the abundance of Cutibacterium acnes decreased in 13 of 15 cases, and that of Staphylococcus aureus, Corynebacterium spp., Staphylococcus epidermidis or Proteobacteria increased in 13 of 15 cases after EGFRIs initiation. Skin pH increased significantly in parallel with a decrease in water capacitance after EGFRI initiation. Also, the composition of the skin microbiome of patients with severe rash was significantly different from that of healthy controls. In addition, the skin dysbiosis did not return to baseline during EGFRIs treatment for >1 year. These longitudinal observations indicate that skin dysbiosis is associated with development of skin rash.

The second nationwide surveillance of antibacterial susceptibility patterns of pathogens isolated from skin and soft-tissue infections in dermatology departments in Japan.

The present study compared trends in antimicrobial resistance patterns in pathogens isolated from skin and soft-tissue infections (SSTIs) in Japan with those of a nationwide survey conducted in 2013. Three organisms that caused most of the SSTIs were collected from 12 dermatology departments in medical centers and 12 dermatology clinics across Japan between April 2019 and August 2020. A total of 390 strains, including 267 Staphylococcus aureus, 109 coagulase-negative staphylococci (CNS), and 14 Streptococcus pyogenes strains were submitted to a central laboratory for antimicrobial susceptibility testing. Patient demographic and clinical information was collated. Methicillin-resistant S. aureus (MRSA) was detected in 25.8% (69/267) of the S. aureus strains. The prevalence of MRSA between the present study and the 2013 survey did not differ significantly. Furthermore, there were no significant differences in MIC values and susceptibility patterns of the MRSA strains to other agents, regardless of a history of hospitalization within 1 year or invasive medical procedures. Methicillin-resistant CNS (MRCNS) was detected in 48.6% (53/109) of CNS isolates, higher than the 35.4% prevalence in the 2013 survey. This difference could be attributed to the heterogeneity in the members of the MRCNS, which comprises multiple staphylococci species, between the 2013 and 2019 surveys. However, it was noted that the susceptibility profiles of the MRCNS to each antibiotic were not significantly different from those identified in the 2013 survey. Most strains of S. pyogenes were susceptible to each antibiotic, similar to the 2013 survey. Continuous monitoring of trends in pathogen and susceptibility profiles is important to advise local public health efforts regarding the appropriate treatment of SSTIs.

Prevalence of Psoriatic Arthritis in Nagano Prefecture, Japan, and Efficacy of the Psoriasis Epidemiology Screening Tool: A Real-World Survey.

Pain, stiffness, and swelling are the main joint symptoms of psoriatic arthritis (PsA); however, they are also common symptoms of other joint diseases. Therefore, it is challenging to distinguish PsA from other joint diseases. To evaluate the prevalence of PsA and the frequency of joint symptoms in psoriasis patients, we conducted a prefecture-wide survey using the Psoriasis Epidemiology Screening Tool (PEST), a patient questionnaire for screening PsA to assess joint symptoms. Data were collected from 764 psoriasis patients, all of whom visited hospitals (55.1%) or clinics (44.9%) in Nagano Prefecture, Japan. The proportion of psoriasis patients with PsA was 6.5% (50 of 764); four patients (1.2%) with PsA were treated in clinics, while 46 patients (10.9%) were treated in hospitals. Based on the responses to the PEST, 18.1% of patients with psoriasis had joint symptoms. In contrast, 73.2% of psoriasis patients with joint symptoms did not have PsA. The PEST showed 52% sensitivity and 93.4% specificity for PsA. In addition, fingernail alterations were common in PsA. The proportion of the population with PsA was lower than reported previously in Japan. This may have been due to the enrollment of a large number of patients treated in clinics. Many patients with PsA were treated at hospitals, which likely reflects the tendency of patients with joint symptoms to receive intensive treatment in hospitals. In addition, based on the lower sensitivity of the PEST in this study, further studies are necessary to establish the validity of the PEST.

Changes in the Immune Cell Repertoire for the Treatment of Malignant Melanoma.

Immune checkpoint inhibitors (ICIs) have been used for the treatment of various types of cancers, including malignant melanoma. Mechanistic exploration of tumor immune responses is essential to improve the therapeutic efficacy of ICIs. Since tumor immune responses are based on antigen-specific immune responses, investigators have focused on T cell receptors (TCRs) and have analyzed changes in the TCR repertoire. The proliferation of T cell clones against tumor antigens is detected in patients who respond to treatment with ICIs. The proliferation of these T cell clones is observed within tumors as well as in the peripheral blood. Clonal proliferation has been detected not only in CD8-positive T cells but also in CD4-positive T cells, resident memory T cells, and B cells. Moreover, changes in the repertoire at an early stage of treatment seem to be useful for predicting the therapeutic efficacy of ICIs. Further analyses of the repertoire of immune cells are desirable to improve and predict the therapeutic efficacy of ICIs.

Transcription Factors Runx1 and Runx3 Suppress Keratin Expression in Undifferentiated Keratinocytes.

The Runt-related transcription factor (Runx) family has been suggested to play roles in stem cell regulation, tissue development, and oncogenesis in various tissues/organs. In this study, we investigated the possible functions of Runx1 and Runx3 in keratinocyte differentiation. Both Runx1 and Runx3 proteins were detected in primary cultures of mouse keratinocytes. Proteins were localized in the nuclei of undifferentiated keratinocytes but translocated to the cytoplasm of differentiated cells. The siRNA-mediated inhibition of Runx1 and Runx3 expression increased expression of keratin 1 and keratin 10, which are early differentiation markers of keratinocytes. In contrast, overexpression of Runx1 and Runx3 suppressed keratin 1 and keratin 10 expression. Endogenous Runx1 and Runx3 proteins were associated with the promoter sequences of keratin 1 and keratin 10 genes in undifferentiated but not differentiated keratinocytes. In mouse skin, the inhibition of Runx1 and Runx3 expression by keratinocyte-specific gene targeting increased the ratios of keratin 1- and keratin 10-positive cells in the basal layer of the epidermis. On the other hand, inhibition of Runx1 and Runx3 expression did not alter the proliferation capacity of cultured or epidermal keratinocytes. These results suggest that Runx1 and Runx3 likely function to directly inhibit differentiation-induced expression of keratin 1 and keratin 10 genes but are not involved in the regulation of keratinocyte proliferation.

Effect of adalimumab on axial manifestations in Japanese patients with psoriatic arthritis: a 24 week prospective, observational study.

OBJECTIVES: PsA is characterized by enthesitis, synovitis and osseous involvement in the peripheral and axial joints. Few studies have examined axial involvement in PsA using imaging techniques. Here we examined axial involvement in PsA patients using MRI. In addition, we determined the efficacy of 24 week adalimumab treatment in improving the MRI findings of spondylitis and sacroiliitis. METHODS: This was a prospective, open-label, single-arm study in patients with PsA. Adalimumab was administered to patients for a total of 24 weeks. MRI examinations were conducted at baseline and at week 24 of adalimumab treatment. RESULTS: Thirty-seven patients with PsA were included in this study. Spondylitis was observed in at least one site of the positive scan in 91% (n = 31) of patients with PsA. The number of arthritic sites in the cervical, thoracic and lumbar regions of the spine was 48, 67 and 53, respectively. All patients had MRI-determined sacroiliitis of grade ≥1 severity while 28 patients (82%) had grade ≥2 sacroiliitis in at least one sacroiliac region. Sacroiliac arthritis was statistically more severe on the right side than on the left side (P < 0.05). In 34 patients with PsA, the thoracic spine was the most common site of spondylitis. In addition, 24 week adalimumab treatment led to an improvement in the mean number of spondylitis sites and the mean grade of sacroiliitis. CONCLUSION: Treatment with adalimumab for 24 weeks resulted in improvement in spondylitis and sacroiliitis.

Usefulness of monitoring circulating tumor cells as a therapeutic biomarker in melanoma with BRAF mutation.

BACKGROUND: While molecularly targeted therapies and immune checkpoint inhibitors have improved the prognosis of advanced melanoma, biomarkers are required to monitor drug responses. Circulating tumor cells (CTCs) are released from primary and/or metastatic tumors into the peripheral blood. We examined whether CTCs have potential as biomarkers by checking the number of CTCs, as well as the BRAF genotype of individual CTCs, in melanoma patients undergoing BRAF/MEK inhibitor treatment. METHODS: CTCs were isolated from peripheral blood using a high-density dielectrophoretic microwell array, followed by labeling with melanoma-specific markers (MART-1 and/or gp100) and a leukocyte marker (CD45). The numbers of CTCs were analyzed in fifteen patients with stage 0-III melanoma. Furthermore, changes in CTC numbers were assessed in five patients with stage IV melanoma at four time points during BRAF/MEK inhibitor treatment, and the BRAF genotype was analyzed in CTCs isolated from one patient. RESULTS: We examined CTCs in patients with stage 0-III (five samples per stage: stage 0-I, stage II, and stage III), and detected CTCs even in patients with early disease (stage 0 and I). Interestingly, recurrence occurred in the lymph nodes of one stage I patient 2 years after the detection of a high number of CTCs in the patient's blood. The total number of CTCs in four of five patients with stage IV melanoma fluctuated in response to BRAF/MEK inhibitor treatment, suggesting that CTC number has potential for use as a drug response marker in advanced disease patients. Interestingly, one of those patients had CTCs harboring seven different BRAF genotypes, and the mutated CTCs disappeared upon BRAF/MEK inhibitor treatment, except for those harboring BRAFA598V. CONCLUSIONS: CTCs are present even in the early stage of melanoma, and the number of CTCs seems to reflect patients' responses to BRAF/MEK inhibitor treatment. Furthermore, genetic heterogeneity of BRAF may contribute to resistance to BRAF/MEK inhibitors. Our findings demonstrate the usefulness of CTC analysis for monitoring responses to targeted therapies in melanoma patients, and for understanding the mechanism of drug resistance.

Ligand Bound Fatty Acid Binding Protein 7 (FABP7) Drives Melanoma Cell Proliferation Via Modulation of Wnt/ß-Catenin Signaling.

PURPOSE: Fatty acid-binding protein 7 (FABP7) involved in intracellular lipid dynamics, is highly expressed in melanomas and associated with decreased patient survival. Several studies put FABP7 at the center of melanoma cell proliferation. However, the underlying mechanisms are not well deciphered. This study examines the effects of FABP7 on Wnt/ß-catenin signaling that enhances proliferation in melanoma cells. METHODS: Skmel23 cells with FABP7 silencing and Mel2 cells overexpressed with wild-type FABP7 (FABP7wt) and mutated FABP7 (FABP7mut) were used. Cell proliferation and migration were analyzed by proliferation and wound-healing assay, respectively. Transcriptional activation of the Wnt/ß-catenin signaling was measured by luciferase reporter assay. The effects of a specific FABP7 inhibitor, MF6, on proliferation, migration, and modulation of the Wnt/ß-catenin signaling were examined. RESULTS: FABP7 siRNA knockdown in Skmel23 decreased proliferation and migration, cyclin D1 expression, as well as Wnt/ß-catenin activity. Similarly, FABP7wt overexpression in Mel2 cells increased these effects, but FABP7mut abrogated these effects. Pharmacological inhibition of FABP7 function with MF6 suppressed FABP7-regulated proliferation of melanoma cells. CONCLUSION: These results suggest the importance of the interaction between FABP7 and its ligands in melanoma proliferation modulation, and the beneficial implications of therapeutic targeting of FABP7 for melanoma treatment.

Recent advances in molecular targeted therapy for unresectable and metastatic BRAF-mutated melanoma.

The clinical outcome of BRAF-mutated advanced melanoma has been improved by both molecular targeted therapies and immune checkpoint inhibitors. Long-term follow-up data reveal durable clinical responses in patients receiving first-line combinations of BRAF inhibitors plus MEK inhibitors, particularly those showing a complete response. Clinical outcomes are also associated with the lactate dehydrogenase levels and the number of metastatic organs. Although brain metastasis is frequently difficult to control, systemic therapy is preferred in cases with small and asymptomatic brain metastases associated with progressive extra-cranial disease. Control of intra-cranial disease with BRAF inhibitors plus MEK inhibitors is comparable with that of immune checkpoint inhibitors, although immune checkpoint inhibitors are superior to targeted therapies with respect to survival. The BRAF inhibitors plus MEK inhibitors regimen is well-tolerated, and toxicities are usually manageable and reversible, but differ according to the specific regimen used. Guidelines in the United States, Europe, and Japan recommend targeted therapy for patients who need early tumor responses. A meta-analysis of retrospective data shows that the baseline lactate dehydrogenase level is significantly higher in patients treated with BRAF inhibitors plus MEK inhibitors than in those treated with immune checkpoint inhibitors, suggesting that clinicians tend to use BRAF inhibitors plus MEK inhibitors for more advanced disease. Since there is insufficient efficacy and safety data on the use of targeted therapies for acral and mucosal melanoma, a retrospective analysis may be useful. The combination of molecular targeted therapy plus immune checkpoint inhibitors is expected to elicit further improvement. The results of several trials using combination or sequential therapies will be available in the next few years.

Renin-Angiotensin System in the Tumor Microenvironment.

For enhancing the antitumor effects of current immunotherapies including immune-checkpoint blockade, it is important to reverse cancer-induced immunosuppression. The renin-angiotensin system (RAS) controls systemic body fluid circulation; however, the presence of a local RAS in tumors has been reported. Furthermore, the local RAS in tumors influences various immune and interstitial cells and affects tumor immune response. RAS stimulation through the angiotensin II type 1 receptor has been reported to inhibit tumor immune response. Therefore, RAS inhibitors and combined treatment with immunotherapy are expected in the future. In this chapter, we provide a background on the RAS and describe the tumor environment with regard to the RAS and tumor immune response.

Role of Innate Immune Cells in Psoriasis.

Psoriasis is a chronic inflammatory skin condition caused by a combination of hereditary and environmental factors. Its development is closely related to the adaptive immune response. T helper 17 cells are major IL-17-producing cells, a function that plays an important role in the pathogenesis of psoriasis. However, recent findings have demonstrated that innate immune cells also contribute to the development of psoriasis. Innate lymphoid cells, γδ T cells, natural killer T cells, and natural killer cells are activated in psoriasis, contributing to disease pathology through IL-17-dependent and -independent mechanisms. The present review provides an overview of recent findings, demonstrating a role for innate immunity in psoriasis.

Significance of 5-S-Cysteinyldopa as a Marker for Melanoma.

Melanoma is one of the most lethal and malignant cancers and its incidence is increasing worldwide, and Japan is not an exception. Although there are numerous therapeutic options for melanoma, the prognosis is still poor once it has metastasized. The main concern after removal of a primary melanoma is whether it has metastasized, and early detection of metastatic melanoma would be effective in improving the prognosis of patients. Thus, it is very important to identify reliable methods to detect metastases as early as possible. Although many prognostic biomarkers (mainly for metastases) of melanoma have been reported, there are very few effective for an early diagnosis. Serum and urinary biomarkers for melanoma diagnosis have especially received great interest because of the relative ease of sample collection and handling. Several serum and urinary biomarkers appear to have significant potential both as prognostic indicators and as targets for future therapeutic methods, but still there are no efficient serum and urinary biomarkers for early detection, accurate diagnosis and prognosis, efficient monitoring of the disease and reliable prediction of survival and recurrence. Levels of 5-S-cysteinyldopa (5SCD) in the serum or urine as biomarkers of melanoma have been found to be significantly elevated earlier and to reflect melanoma progression better than physical examinations, laboratory tests and imaging techniques, such as scintigraphy and echography. With recent developments in the treatment of melanoma, studies reporting combinations of 5SCD levels and new applications for the treatment of melanoma are gradually increasing. This review summarizes the usefulness of 5SCD, the most widely used and well-known melanoma marker in the serum and urine, compares 5SCD and other useful markers, and finally its application to other fields.

Efficacy and safety of adalimumab in Japanese patients with psoriatic arthritis and inadequate response to non-steroidal anti-inflammatory drugs (NSAIDs): A prospective, observational study.

Objectives: To evaluate the efficacy and safety of adalimumab in psoriatic arthritis (PsA) patients in Japan.Methods: In this open-label, single-arm study conducted at six sites from October 2014 to June 2016 (UMIN000016543), PsA patients (≥20 years old) with inadequate response to nonsteroidal anti-inflammatory drugs received adalimumab subcutaneously (80 mg initially, then 40 mg every other week; 24 weeks total). Primary endpoint was American College of Rheumatology 20% improvement (ACR20) response rate at week 12.Results: Of 42 enrolled patients, 37 were treated (mean (SD) age, 56.2 (13.0) years; male, 27 (73.0%)). ACR20, ACR50, and ACR70 response rates were 40.5%, 24.3%, and 16.2% at week 12 and increased to 45.9%, 37.8%, and 21.6% at week 24, respectively. Psoriasis Area and Severity Index (PASI) 50 response rates were unchanged at weeks 12 and 24 (73%), but PASI75 and PASI90 increased from 40.5% and 21.6% to 59.5% and 40.5%, respectively. Other indices such as Physician's Global Assessment score, C-reactive protein-based disease activity score in 28 joints, Bath Ankylosing Spondylitis Disease Activity Index, and serum biomarker levels were significantly improved. No unexpected adverse events were reported.Conclusion: Similar to the global population, adalimumab was efficacious and well tolerated in Japanese treatment-experienced PsA patients.

Involvement of local renin-angiotensin system in immunosuppression of tumor microenvironment.

To improve current cancer immunotherapies, strategies to modulate various immunosuppressive cells including myeloid derived suppressor cells (MDSC) which were shown to be negative factors in immune-checkpoint blockade therapy, need to be developed. In the present study, we evaluated the role of the local renin-angiotensin system (RAS) in the tumor immune-microenvironment using murine models bearing tumor cell lines in which RAS was not involved in their proliferation and angiogenetic ability. Giving angiotensin II receptor blockers (ARB) to C57BL/6 mice bearing murine colon cancer cell line MC38 resulted in significant enhancement of tumor antigen gp70 specific T cells. ARB administration did not change the numbers of CD11b+ myeloid cells in tumors, but significantly reduced their T-cell inhibitory ability along with decreased production of various immunosuppressive factors including interleukin (IL)-6, IL-10, vascular endothelial growth factor (VEGF), and arginase by CD11b+ cells in tumors. ARB also decreased expression of immunosuppressive factors such as chemokine ligand 12 and nitric oxide synthase 2 in cancer-associated fibroblasts (CAF). Last, combination of ARB and anti-programmed death-ligand 1 (PD-L1) antibodies resulted in significant augmentation of anti-tumor effects in a CD8+ T cell-dependent way. These results showed that RAS is involved in the generation of an immunosuppressive tumor microenvironment caused by myeloid cells and fibroblasts, other than the previously shown proliferative and angiogenetic properties of cancer cells and macrophages, and that ARB can transform the immunosuppressive properties of MDSC and CAF and could be used in combination with PD-1/PD-L1 immune-checkpoint blockade therapy.

Circulating Tumour DNA for Monitoring Treatment Response to Anti-PD-1 Immunotherapy in Melanoma Patients.

Anti-programmed cell death-1 (anti-PD-1) antibody shows high therapeutic efficacy in patients with advanced melanoma. However, assessment of its therapeutic activity can be challenging because of tumour enlargement associated with intratumoural inflammation. Because circulating tumour DNA (ctDNA) correlates with tumour burden, we assessed the value of ctDNA levels as an indicator of tumour changes. Quantification of ctDNA (BRAFmutant or NRASmutant) levels by droplet digital PCR in 5 patients with BRAF or NRAS mutant melanoma during the treatment course showed dynamic changes corresponding to radiological and clinical alterations. In 3 cases in which the anti-PD-1 antibody was effective, ctDNA levels decreased within 2-4 weeks after treatment initiation. In 2 cases in which the anti-PD-1 antibody was ineffective, ctDNA levels did not decrease after treatment initiation. ctDNA could be a useful biomarker to predict early response to treatment in patients with advanced melanoma treated with anti-PD-1 immunotherapy.