GWAS for systemic sclerosis identifies six novel susceptibility loci including one in the Fcγ receptor region.

Here we report the largest Asian genome-wide association study (GWAS) for systemic sclerosis performed to date, based on data from Japanese subjects and comprising of 1428 cases and 112,599 controls. The lead SNP is in the FCGR/FCRL region, which shows a penetrating association in the Asian population, while a complete linkage disequilibrium SNP, rs10917688, is found in a cis-regulatory element for IRF8. IRF8 is also a significant locus in European GWAS for systemic sclerosis, but rs10917688 only shows an association in the presence of the risk allele of IRF8 in the Japanese population. Further analysis shows that rs10917688 is marked with H3K4me1 in primary B cells. A meta-analysis with a European GWAS detects 30 additional significant loci. Polygenic risk scores constructed with the effect sizes of the meta-analysis suggest the potential portability of genetic associations beyond populations. Prioritizing the top 5% of SNPs of IRF8 binding sites in B cells improves the fitting of the polygenic risk scores, underscoring the roles of B cells and IRF8 in the development of systemic sclerosis. The results also suggest that systemic sclerosis shares a common genetic architecture across populations.

Elevated Alpha 1(I) to Alpha 2(I) Collagen Ratio in Dermal Fibroblasts Possibly Contributes to Fibrosis in Systemic Sclerosis.

Systemic sclerosis (SSc) is characterized by excessive collagen deposition in the skin and internal organs. Activated fibroblasts are the key effector cells for the overproduction of type I collagen, which comprises the α1(I) and α2(I) chains encoded by COL1A1 and COL1A2, respectively. In this study, we examined the expression patterns of α1(I) and α2(I) collagen in SSc fibroblasts, as well as their co-regulation with each other. The relative expression ratio of COL1A1 to COL1A2 in SSc fibroblasts was significantly higher than that in control fibroblasts. The same result was observed for type I collagen protein levels, indicating that α2(I) collagen is more elevated than α2(I) collagen. Inhibition or overexpression of α1(I) collagen in control fibroblasts affected the α2(I) collagen levels, suggesting that α1(I) collagen might act as an upstream regulator of α2(I) collagen. The local injection of COL1A1 small interfering RNA in a bleomycin-induced SSc mouse model was found to attenuate skin fibrosis. Overall, our data indicate that α2(I) collagen is a potent regulator of type I collagen in SSc; further investigations of the overall regulatory mechanisms of type I collagen may help understand the aberrant collagen metabolism in SSc.

Genomic landscape of circulating tumour DNA in metastatic extramammary Paget's disease.

Although cancer personalized profiling by deep sequencing (CAPP-Seq) of cell-free DNA (cfDNA) has gained attention, the clinical utility of circulating tumour DNA (ctDNA) in extramammary Paget's disease (EMPD) has not been investigated. In this study, genomic alterations in the cfDNA and tumour tissue DNA were investigated in seven patients with metastatic EMPD. CAPP-Seq revealed mutations in 18 genes, 11 of which have not yet been reported in EMPD. The variant allele frequency of some of the mutated genes reflected the disease course in patients with EMPD. In one patient, the mutation was detected even though imaging findings revealed no metastasis. In another patient with triple EMPD (genital area and both axilla), cfDNA sequencing detected the mutation in a rib metastatic lesion, which was also detected in both axilla lesions but not the genital region. Investigations of the ctDNA may be useful towards the elucidation of clonal evolution in EMPD.

A mechanism of cooling hot tumors: Lactate attenuates inflammation in dendritic cells.

Turning non-inflamed (cold) tumors into inflamed (hot) tumors is important for maximizing the effect of immune checkpoint inhibitors (ICIs) against malignancies. We showed that lactate, a product of the Warburg effect, inhibited the efficacy of ICIs and suppressed IL-12 p40 expression in dendritic cells (DCs) through reducing NF-κB p65, p50, and c-Rel DNA-binding activity to the IL-12 p40 promoter. Additionally, lactate promoted the expression of early growth response protein 1 (EGR1), whose expression was increased in human invasive melanoma compared with non-invasive melanoma. We also found that EGR1 interacts with serum response factor (SRF) and represses the expression of CD80 in DCs. These findings suggest that lactate and its induced EGR1 are key factors that turn hot tumors into cold tumors and may represent targets in cancer treatment with ICIs.

Liquid biopsy-based analysis by ddPCR and CAPP-Seq in melanoma patients.

BACKGROUND: The development of BRAF/MEK inhibitors in patients with metastatic melanoma harboring BRAF mutations has garnered attention for liquid biopsy to detect BRAF mutations in cell-free DNA (cfDNA) using droplet digital PCR (ddPCR) or next-generation sequencing methods. OBJECTIVE: To investigate gene mutations in tumor DNA and cfDNA collected from 43 melanoma patients and evaluate their potential as biomarkers. METHODS: ddPCR and CAncer Personalized Profiling by deep Sequencing (CAPP-Seq) techniques were performed to detect gene mutations in plasma cfDNA obtained from patients with metastatic melanoma. RESULTS: Gene variants, including BRAF, NRAS, TP53, GNAS, and MET, were detectable in the plasma cfDNA, and the results were partially consistent with the results of those identified in the tissues. Among the variants examined, copy numbers of MET mutations were consistent with the disease status in two melanoma patients. CONCLUSION: Liquid biopsy using CAPP-Seq and ddPCR has the potential to detect tumor presence and mutations, especially when tissue biopsies are unavailable. MET mutations in cfDNA may be a potential biomarker in patients with metastatic melanoma.

Overexpression of Janus kinase 2 protein in extramammary Paget's disease.

Extramammary Paget's disease is a rare malignant tumor of the skin that occurs primarily in the genitocrural region. Although the prognosis of extramammary Paget's disease with distant metastasis is poor, an effective therapy has not been established. Because Janus kinase 2 has attracted attention as a therapeutic target in several cancers, we investigated the expression of the Janus kinase 2 protein and the relationship between its level of expression and clinical significance in 53 patients with extramammary Paget's disease in our hospital. Immunohistochemistry showed that most extramammary Paget's disease tissues were positive for Janus kinase 2 (50/53, 94.3%), and the immunostaining intensity of Janus kinase 2 was correlated with the degree of invasiveness, lymph node metastasis and distant metastasis. Based on these findings, Janus kinase 2 may be a promising therapeutic target in extramammary Paget's disease.

Existence of Staphylococcus aureus correlates with the progression of extramammary Paget's disease: potential involvement of interleukin-17 and M2-like macrophage polarization.

BACKGROUND: The microbiome plays an important role in the tumour microenvironment (TME). OBJECTIVES: In this study, we investigated the clinical significance of the microbiota in extramammary Paget's disease (EMPD). MATERIALS & METHODS: Patients with EMPD, treated between March 2007 and September 2019 at Kumamoto University Hospital, were investigated retrospectively. Inclusion criteria included: histological diagnosis of EMPD, inspection of the bacterial culture of the cancer lesion using swab sampling, and availability of sufficient tissue in paraffin blocks for immunohistochemistry. For the latter, primary antibodies against IL-17, CD163 and ionized calcium-binding adapter molecule 1 (Iba1) were used. RESULTS: Bacterial cultures of the cancer lesion revealed that Staphylococcus aureus (S. aureus) was highly prevalent in EMPD patients, with dermal invasion or lymph node metastasis, compared to patients without these findings. Furthermore, the number of IL-17-positive cells and CD163-positive M2-like macrophages (pro-tumour macrophages) were increased in EMPD tissues with S. aureus. Moreover, the number of IL-17-producing cells in EMPD tissues positively correlated with the accumulation of CD163-positive M2-like macrophages. In addition, the percentage of CD163-positive cells within Iba-1-positive macrophages (total macrophages) was also significantly elevated in EMPD tissues with S. aureus. CONCLUSION: Based on these findings, S. aureus may exacerbate the pathological condition of EMPD via the accumulation of IL-17 and M2-like macrophages.

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.

CXCL17-mediated downregulation of type I collagen via MMP1 and miR-29 in skin fibroblasts possibly contributes to the fibrosis in systemic sclerosis.

BACKGROUND: Systemic sclerosis (SSc) is characterized by excessive deposition of collagen in the skin and internal organs. Recent studies have shown that chemokine (C-X-C motif) ligands (CXCLs) are involved in the pathogenesis of SSc. OBJECTIVE: Our aim was to examine the anti-fibrotic potential of CXCL17, a newly discovered chemokine, in cultured skin fibroblasts and in a bleomycin-induced SSc mouse model. Moreover, we examined serum level of CXCL17 in patients with SSc. METHODS: Type I collagen expression was evaluated in SSc skin and cultured fibroblasts treated with CXCL17 using immunoblotting and quantitative reverse transcription-PCR. Serum CXCL17 levels were determined using enzyme-linked immunosorbent assay in 63 patients with SSc and 17 healthy subjects. A bleomycin-induced SSc mouse model was used to evaluate the effect of CXCL17 on skin fibrosis. RESULTS: CXCL17 reduced the expression of type I collagen in healthy control fibroblasts. CXCL17 also induced matrix metalloproteinase 1 (MMP1) and miR-29 expression in fibroblasts, indicating that CXCL17 regulates type I collagen expression in part via post-transcriptional mechanisms through MMP1 and miR-29. We found that local injection of CXCL17 attenuated bleomycin-induced skin fibrosis in mice. CXCL17 levels in SSc skin were lower than those in healthy controls, in contrast to the high serum CXCL17 levels in patients with SSc. The low expression of CXCL17 in SSc skin possibly affects type I collagen accumulation in this disease. CONCLUSION: Our data indicate that understanding CXCL17 signaling may lead to a better therapeutic approach for SSc.

Methyl-CpG binding domain protein 3: a new diagnostic marker and potential therapeutic target of melanoma.

Methyl-CpG binding domain protein 3 (MBD3) belongs to the methyl-CpG binding protein family. MBD3 facilitates the initiation of neural stem cell reprogramming. Melanoma originates in melanocytes derived from neural crest stem cells; therefore, we investigated the role of MBD3 in melanoma. MBD3 was overexpressed in melanoma compared with pigmented nevi. MBD3 knockdown had no effect on the proliferation of melanoma cells (A375 and A2058 cells). Contrarily, it significantly reduced the migration and invasion of A375 cells, but had no significant effect on A2058 cells. Furthermore, MBD3 knockdown reduced N-cadherin protein levels and matrix metalloproteinase-2 (MMP-2) activity in A375 cells, but had no significant effect on A2058 cells. Based on these results, the MBD3 expression level may be a useful biomarker for the diagnosis of melanoma. Thus, MBD3 has potential as a novel therapeutic target for some melanoma patients.

Characteristics of Japanese patients with eosinophilic fasciitis: A brief multicenter study.

Eosinophilic fasciitis is a relatively rare cutaneous fibrotic condition affecting the deep fascia of the extremities, with or without peripheral blood eosinophilia. To examine the characteristics of Japanese patients with eosinophilic fasciitis, we conducted a brief, multicenter, retrospective survey at seven university hospitals. In total, 31 patients were identified as having eosinophilic fasciitis, among whom 30 patients fulfilled the Japanese diagnostic criteria. The male : female ratio was 2.3:1, and the mean age was 47.7 years. Three of the patients were under 20 years old. The possible triggering factors included muscle training, sports, walking or sitting for a long time, physical work, insect bite and drug. Co-occurrence of morphea was observed in nine cases (29%), and malignancies were associated in three (two hematological malignancies and one internal malignancy). Immunological abnormalities in the serum showed positive antinuclear antibody, positive rheumatoid factor, increased aldolase levels and increased immunoglobulin G levels. The patients were treated with either monotherapy or combination therapy by oral prednisolone (20-80 mg/day), methotrexate (6-10 mg/week), cyclosporin (100-150 mg/day), mizoribine, infliximab and phototherapy. Methylprednisolone pulse therapy was performed in six cases. By contrast, spontaneous improvement due to resting only was observed in two cases, and skin hardening was improved by withdrawal of the anticancer drug in one case. This study suggests several characteristics of Japanese patients with eosinophilic fasciitis, namely male predominance, rare pediatric occurrence, immunological abnormalities and coexistence with morphea. Systemic prednisolone is the first-line therapy, but pulse therapy is occasionally required for severe cases. The triggering events of physical stress are not so frequent as have previously been reported, and various factors or even unknown factors may be associated with the induction of eosinophilic fasciitis.

Single administration of avelumab induced a complete response in thyroid transcription factor 1-positive combined Merkel cell carcinoma.

Merkel cell carcinoma (MCC) is an aggressive neoplasm and patients with metastasis have poor survival outcomes. Recently, avelumab, an anti-programmed death ligand 1 (PD-L1) immune checkpoint inhibitor, was approved for first-line treatment in patients with metastatic MCC. While the administration interval of avelumab is every 2 weeks, the durable effect of a single administration of avelumab is unknown. Additionally, the effect of avelumab in pure MCC or combined MCC concurrent with non-MCC histology has not been fully elucidated. Herein, we report a case of combined MCC concurrent with squamous cell carcinoma; the patient had a complete response after a single administration of avelumab. Although the levels of avelumab were outside the detection limit within 12 weeks, a remarkable efficacy remained for more than 28 weeks after administration. Immunohistochemical analyses revealed that the expression of PD-L1 and Merkel cell polyomavirus large T antigen was almost negative or only partial in the primary tumor lesion of this patient. Conversely, thyroid transcription factor 1 (TTF-1) expression was positive in the primary MCC lesion, which is consistent with a previous report that combined MCC is positive for TTF-1 expression. In conclusion, this case study presents a rare case of TTF-1-positive combined MCC showing complete response after a single administration of avelumab.

Circulating tumor necrosis factor-α DNA are elevated in psoriasis.

In psoriasis, tumor necrosis factor (TNF)-α is a key pro-inflammatory cytokine that activates keratinocytes to produce other inflammatory mediators. In addition, increased serum or plasma TNF-α levels are considered to be biomarkers of psoriasis. Circulating cell-free DNA (cfDNA) originates from apoptotic or necrotic cells and reflects the severity of cellular damage. Although cfDNA has recently attracted attention as a marker in the diagnosis and prognosis of various disorders, there are few reports of its clinical implications in the field of dermatology including psoriasis. The aim of this study was to investigate whether the TNF-α gene is present in the cfDNA, and whether its levels can be utilized as a biomarker for patients with psoriasis. cfDNA was isolated from serum samples of 79 patients with psoriasis vulgaris and 29 with psoriatic arthritis. The levels of TNF-α in the cfDNA were assessed by droplet digital polymerase chain reaction. In this study, we made two novel findings. First, circulating TNF-α DNA levels in the cfDNA were significantly higher in patients with psoriasis than in healthy controls. In addition, the area under the curve was 0.91, suggesting that serum TNF-α DNA levels are effective as a diagnostic biomarker. Second, the levels of TNF-α DNA copies in the cfDNA were positively correlated with the Psoriasis Area and Severity Index (PASI) score in the group of patients with a PASI score higher than 10. Generally, a PASI score of more than 10 is defined as severe psoriasis; therefore, the levels of TNF-α DNA copies in the cfDNA could be a biomarker for severity in patients with severe psoriasis. Further studies are needed to establish serum TNF-α DNA levels as a novel biomarker of psoriasis.

Increased CD27 expression in the skins and sera of patients with systemic sclerosis.

Systemic sclerosis (SSc) is a kind of collagen disease and has an acquired autoimmune activation as represented by the production of autoantibodies. CD27 is a type I glycoprotein and a member of the tumor necrosis factor receptor family. It binds to the CD70 ligand, CD27-CD70 signaling is implicated in the development of various autoimmune diseases, but its role in the regulation of extracellular matrix expression and its contribution to the phenotype of SSc both remain to be elucidated. This study aimed to investigate the associations between CD27 and SSc in the skins and sera. Immunohistochemistry were performed to determine the expression of CD27 in the skin. Enzyme-linked immunosorbent assays were done to the sera of the 54 patients with SSc and 23 normal healthy controls. CD27 expression was significantly increased in the affected regions of the skin and the sera of patients of SSc. Thereafter, we evaluated the correlation between the serum soluble CD27 (sCD27) levels and the clinical symptoms. The study subjects with increased sCD27 levels had a significantly higher ratio of dcSSc and to showed higher modified Rodnan's total skin thickness scores (mRSS) than those with normal sCD27 levels. These results suggest that sCD27 levels might be useful for diagnosis of SSc and its severity.