Absence of microsatellite instability in extramammary Paget's disease.

Background: Deficiency of DNA mismatch repair (MMR) induces microsatellite instability (MSI). Pembrolizumab, an antibody targeting PD-1 (an immune checkpoint inhibitor), is more effective against MMR-deficient tumours than against MMR-proficient tumours. The status of MMR is a useful biomarker for predicting the effectiveness of pembrolizumab administration. Although the status of MMR has attracted attention in skin tumours, there are few reports on MSI in extramammary Paget's disease (EMPD). Objectives: To evaluate the status of MMR in patients with EMPD. Materials & Methods: One hundred one patients with EMPD were included. MMR status of the genomic DNA of each subject was analysed using Promega panel (approved as a companion diagnostic agent for the administration of pembrolizumab). Results: MSI testing showed the occurrence rates of MSI-high (more than two markers are unstable), MSI-low (one marker is unstable) and MSS (all markers are stable) tumour tissues were 0% (0/101), 1.0% (1/101) and 99.0% (100/101), respectively. Conclusion: The status of MMR may not be useful for the potential therapeutic application of pembrolizumab.

Serum cell-free DNA levels are a useful marker for extramammary Paget disease.

BACKGROUND: Although carcinoembryonic antigen (CEA) and cytokeratin 19 fragment (CYFRA) are useful markers for extramammary Paget disease (EMPD), serum CEA and CYFRA levels are not elevated in most patients with EMPD without metastasis. Cell-free (cf)DNA has attracted attention as an indicator of clinical conditions in several cancers. OBJECTIVES: To identify further useful biomarkers for the detection of EMPD, including early lesions, and to study the clinical implications of cfDNA in EMPD. METHODS: cfDNA were isolated from serum of patients with EMPD with and without metastasis, and from healthy volunteers. Serum extracts were amplified using polymerase chain reaction. RESULTS: Serum cfDNA levels were significantly elevated in patients with EMPD with or without metastasis compared with those in healthy controls. Serum cfDNA was a better diagnostic marker for the presence of EMPD than serum CYFRA. Moreover, the postoperative serum cfDNA levels were significantly lower than those from the preoperative samples, and the change in serum cfDNA levels reflected the clinical courses of patients with EMPD treated with chemotherapy. CONCLUSIONS: Taking the evidence together, serum cfDNA levels may be a useful marker for diagnosis and disease progression in EMPD. What's already known about this topic? Serum levels of carcinoembryonic antigen (CEA) and cytokeratin 19 fragment (CYFRA) are not elevated in most patients with extramammary Paget disease (EMPD) without metastasis. Cell-free (cf)DNA has attracted attention as an indicator of clinical conditions in several cancers. There are few reports of the clinical implications of cfDNA in dermatology. What does this study add? Serum cfDNA levels were significantly elevated in patients with EMPD with or without metastasis compared with those in healthy controls. Postoperative serum cfDNA levels were significantly lower than those from the preoperative samples. Changes in serum cfDNA levels reflected the clinical courses of patients with EMPD treated with chemotherapy. What is the translational message? Serum cfDNA levels in patients with EMPD are a useful marker for the detection of EMPD, including localized EMPD. Changes in serum cfDNA levels in an individual patient may reflect the clinical course of EMPD.

The role of PSMB9 upregulated by interferon signature in the pathophysiology of cutaneous lesions of dermatomyositis and systemic lupus erythematosus.

BACKGROUND: Dermatomyositis (DM) and systemic lupus erythematosus (SLE) have common skin features, including dermal mucin deposition and interferon signature, although their roles are unknown. OBJECTIVES: To identify common or specific molecular changes in DM and SLE skin. METHODS: Proteomic analysis was performed using DM and healthy skin. Glycosaminoglycans were analysed by high-performance liquid chromatography. RESULTS: The expression of 60 proteins was upregulated or downregulated in DM skin compared with healthy skin in the proteomic analysis. Among those proteins, PSMB9, an immunoproteasome subunit, was upregulated in the epidermis of DM and SLE, but not in other skin diseases. Furthermore, versican V1, a core protein for glycosaminoglycans, was upregulated, while type I collagen was downregulated in the dermis of DM and SLE skin. Interferon stimulated PSMB9 expression in cultured keratinocytes and reduced collagen expression in dermal fibroblasts, but did not affect versican expression. The PSMB9 knock-down in keratinocytes led to significant suppression of transforming growth factor (TGF)-ß2 and TGF-ß3, inducers of versican synthesis. TGF-ß3 expression was upregulated in both DM and SLE, while TGF-ß2 expression was increased only in the DM epidermis. ΔDiHS-diS1, a component of heparan sulfate, was significantly increased only in DM. TGF-ß2 expression significantly increased the ΔDiHS-diS1 expression in dermal fibroblasts in vitro. CONCLUSIONS: The interferon signature in DM and SLE skin reduces collagen in dermal fibroblasts, whereas overexpression of PSMB9 induced by interferon stimulates versican inducers in epidermal keratinocytes. In addition, the TGF-ß2-ΔDiHS-diS1 pathway may be responsible for the specific molecular change in DM skin.

Role of c-Jun N-terminal kinase isoforms in the cellular activity of melanoma cell lines.

BACKGROUND: The c-Jun N-terminal kinase (JNK) is thought to be involved in inflammation, proliferation and apoptosis. AIM: To examine the role of JNK isoforms in metastasis, proliferation, migration and invasion of the malignant melanoma (MM) cell lines SK-MEL-28, SK-MEL-3 and WM164, using a kinase-specific inhibitor or isoform-specific small interfering (si)RNAs. RESULTS: SK-MEL-3, a cell line established from metastatic MM, showed slightly increased phosphorylation of both JNK1 and JNK2, whereas WM164, a cell line derived from primary MM, showed significant phosphorylation of JNK1. A JNK inhibitor, SP600125, inhibited cell proliferation of SK-MEL-3 but not SK-MEL-28 or WM164. Transfection of JNK1-specific siRNA reduced the migratory activity of WM164 cells, while silencing of either JNK1 or JNK2 strongly suppressed the invasive activity of SK-MEL-3. CONCLUSIONS: Our study suggests that JNK isoforms have different roles in MM. Metastasis of MM may be regulated by JNK2, while invasion is regulated by both JNK1 and JNK2. JNK1 and JNK2 respectively mediate cell migration and cell proliferation. Further understanding of the specific roles of JNK isoforms in the pathogenesis of MM may lead to the development of therapies targeting specific isoforms.

Serum epidermal growth factor receptor levels in patients with malignant melanoma.

BACKGROUND: Epidermal growth factor receptor (EGFR) is known to be abnormally expressed in many human carcinomas, suggesting that there may be an increase in serum EGFR levels in patients with malignant melanoma (MM) and that this might be a possible new tumour marker. AIM: To assess whether serum EGFR levels might be a marker of MM. METHODS: Serum samples were obtained from 66 patients with MM and 12 healthy controls, and EGFR levels were measured by double-determinant ELISA. RESULTS: Patients with in situ or stage I MM had significantly higher serum EGFR levels compared with healthy controls. Interestingly, serum EGFR levels decreased gradually with the stage of the tumour, being highest at stage I and lowest at stage IV. There was also a trend towards a reverse correlation between tumour thickness and serum EGFR levels. Moreover, a longitudinal study identified a trend for serum EGFR levels in patients with preoperative MM to decrease compared with patients with recurrent MM. CONCLUSIONS: To our knowledge, this is the first report investigating the serum EGFR levels of patients with MM, and gives new insight into the relationship between EGFR and MM. We found that serum EGFR levels were significantly increased in patients with early-stage MM such as in situ and stage I tumours. Measurements of serum EGFR levels might be of clinical value in the detection of early-stage MM.

Overexpression of hepatocyte growth factor receptor in scleroderma dermal fibroblasts is caused by autocrine transforming growth factor ß signaling.

Cutaneous fibrosis seen in systemic sclerosis (SSc) is caused by fibroblast activation and abnormal collagen accumulation due to 'autocrine transforming growth factor (TGF)-ß/Smad signaling'. Hepatocyte growth factor (HGF) may have therapeutic value against SSc, because of its inducible effect on the expression of matrix metalloproteinase (MMP)-1. Previous studies indicated SSc dermal fibroblasts overexpress HGF receptor c-met, which suggest specific and effective induction of MMP-1 in SSc fibroblasts caused by HGF treatment. However, the exact mechanism of c-met overexpression in SSc cells was hardly investigated. We hypothesized that such c-met overexpression is also caused by autocrine TGF-ß/Smad signaling. Expression of c-met protein in cultured SSc dermal fibroblasts was significantly up-regulated compared with that in normal fibroblasts. Ectopic TGF-ß stimulation induced c-met synthesis in normal fibroblasts, while a TGF-ß knockdown normalized the up-regulated c-met levels in SSc fibroblasts. Furthermore, we found the c-met promoter contains a putative binding site for Smads, and the binding activity of Smad2/3 to the c-met promoter was constitutively up-regulated in SSc fibroblasts as well as in normal fibroblasts treated with exogenous TGF-ß1. Taken together, c-met may be overexpressed due to autocrine TGF-ß/Smad signaling in SSc. Considering that HGF has an antifibrotic effect, such c-met overexpression in SSc fibroblasts may be a negative feedback against cutaneous fibrosis. Clarifying the mechanisms of c-met overexpression and controlling the HGF/c-met pathway may lead to a new therapeutic approach for this disease.

Circulating miR-142-3p levels in patients with systemic sclerosis.

BACKGROUND: Recently, increased evidence has shown that serum micro (mi)RNA levels are a useful biomarker for the diagnosis, prognosis and therapeutic value of various diseases. However, serum miRNA has not been investigated in patients with systemic sclerosis (SSc), to our knowledge. AIM: To investigate the possibility that serum levels of Homo sapiens miR-142 stem-loop (hsa-miR-142-3p), one of the miRNAs regulating the expression of integrin αV, could be a specific disease marker for SSc. METHODS: Serum samples were obtained from 61 patients with SSc and 20 healthy controls. Patients with systemic lupus erythematosus (SLE), dermatomyositis (DM) and scleroderma spectrum disorder (SSD), who did not fulfil American College of Rheumatology criteria for SSc but might develop SSc in the future, were included as disease controls in this study. miRNAs were purified from serum, and miR-142-3p levels were measured with a quantitative real-time PCR assay. RESULTS: Serum miR-142-3p levels in patients with SSc were significantly higher than in patients with SSD, SLE or DM, and healthy control groups. Patients with increased miR-142-3p levels tended to have a short sublingual frenulum. CONCLUSIONS: Our data indicate that serum levels of miR-142-3p may be elevated specifically in patients with SSc, correlating with the severity of this disease, and may be useful diagnostic markers for the presence of SSc and for the differentiation of SSc from SSD.

The expression of HER-2 in extramammary Paget's disease.

Extramammary Paget's disease (EMPD) is a rare intraepidermal adenocarcinoma. The common sites of EMPD involvement are the vulva, perineal, perianal, scrotal and penile skin. Several studies have shown that HER-2/neu, also known as c-erbB-2, is amplified and overexpressed in many cancers. In this study, we investigated the expression and clinical significance of HER-2 in Japanese patients with EMPD. Keratinocytes in epidermis were slightly positive for HER-2. As for EMPD, 19 of 31 EMPD were positive for HER-2 (61%). There is significant correlation between the presence of invasion and strong positivity (3+) for HER-2 (p < 0.02). Furthermore, there is significant correlation between the presence of lymph node metastasis and strong positivity (3+) for HER-2 (p < 0.02). These results suggest that patients with EMPD strongly positive for HER-2 may have high risk for lymph node metastasis and should be followed up carefully. The observed overexpression of HER-2 in EMPD presents a potential therapeutic target for adjuvant treatment of this disease. Treatment with trastuzumab is well established in breast cancer with HER-2 overexpression and is recommended by several consensus statements. The results of the present study indicate that targeting therapies for HER-2, such as trastuzumab, may be used for EMPD particularly in patients with invasive and/or metastatic EMPD.

microRNA-mediated keratinocyte hyperproliferation in psoriasis vulgaris.

BACKGROUND: Psoriasis is a chronic inflammatory skin disease characterized by intense proliferation and abnormal differentiation of keratinocytes, although the pathogenesis is still not completely clarified. OBJECTIVES: We investigated the mechanism of keratinocyte proliferation seen in psoriasis, focusing on microRNA (miRNA). MATERIALS AND METHODS: miRNAs were extracted from tissues and sera of psoriasis, atopic dermatitis and healthy control. To determine pathogenic miRNAs, we performed miRNA polymerase chain reaction (PCR) array analysis. The results were confirmed with quantitative real-time PCR, in situ hybridization, immunohistochemistry, transient transfection of siRNA and inhibitor in cultured keratinocytes and Western blotting. RESULTS: PCR array analysis using tissue miRNA demonstrated miR-424 level was markedly decreased in psoriasis skin in vivo. Protein expression of mitogen-activated protein kinase kinase 1 (MEK1) or cyclin E1, predicted target genes of miR-424, was increased in psoriatic skin, although their mRNA levels were not. The transfection of specific inhibitor of miR-424 in normal human keratinocytes led to upregulation of MEK1 or cyclin E1 protein, and resulted in increased cell proliferation. On the other hand, cell number was significantly decreased when cells were transfected with siRNA for MEK1 or cyclin E1. Furthermore, we first investigated serum miRNA levels in psoriasis. Although not significant, serum miR-424 concentration tended to be decreased in patients with psoriasis compared with healthy controls. CONCLUSIONS: Decreased miR-424 expression and subsequently increased MEK1 or cyclin E1 may play a key role in the pathogenesis of psoriasis. Investigation of the regulatory mechanisms of keratinocyte proliferation by miRNA may lead to new treatments and a disease activity marker.