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.

The Warburg effect and tumour immune microenvironment in extramammary Paget's disease: overexpression of lactate dehydrogenase A correlates with immune resistance.

BACKGROUND: Extramammary Paget's disease (EMPD) is a rare malignant skin cancer. One of the hallmarks of cancers, including EMPD, is an enhancement of aerobic glycolysis, which is also known as the Warburg effect. In the last step of glycolysis, the enzyme lactate dehydrogenase A (LDHA) catalyzes the conversion of pyruvate to lactic acid, the accumulation of which contributes to the creation of an acidic tumour microenvironment. This in turn results in immunosuppression in various types of cancers. However, the contribution of these pathways has not been well-studied in EMPD. OBJECTIVE: To investigate the significance of the Warburg effect and its contribution to the tumour immune microenvironment in EMPD. METHODS: The mRNA expression levels of molecules involved in glycolysis and immune-related cytokines were examined by ddPCR. The number of immune cells was assessed by immunohistochemistry (IHC). RESULTS: The levels of two glycolytic enzymes, HK2 and LDHA, in tumour tissues were significantly increased compared to those in paired-normal tissues. IHC analyses revealed increased numbers of PD-L1+ , PD-1+ , CD163+ M2 macrophages, Iba1+ macrophages and Foxp3+ Tregs that were associated with high LDHA levels in EMPD. ddPCR demonstrated that multiple cytokines including IL-4, IL-6, IL-10, TGF-ß and CCL-2 were upregulated and associated with high LDHA levels in EMPD. Statistical analyses showed that IL-6 mRNA expression correlated with the number of CD163+ , Iba-1+ and Foxp3+ cells. CONCLUSION: The Warburg effect contributes to immunomodulation in the tumour microenvironment and further elucidation may lead to better understanding of the pathogenesis of EMPD.

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.

Inhibition of heat shock protein 90 exerts an antitumour effect in angiosarcoma: involvement of the vascular endothelial growth factor signalling pathway.

BACKGROUND: Angiosarcoma is a rare malignant neoplasm derived from endothelial cells, and because advanced angiosarcoma is resistant to standard chemotherapy its prognosis is poor. Therefore, new therapies are urgently needed. Heat shock protein (HSP)90 has been identified as a molecular chaperone that regulates various cancer-related proteins. Numerous clinical trials are currently testing the effectiveness of HSP90 inhibitors in various types of malignancies. OBJECTIVES: To investigate the role of HSP90 in the pathogenesis of angiosarcoma and whether the inhibition of HSP90 may have antitumour activity. METHODS: The expression of HSP90 protein in angiosarcoma was examined using immunohistochemistry and immunoblotting. The effects of HSP90 inhibition were proven using proliferation, migration and invasion assay in angiosarcoma cells. The mechanism of antitumour effect by HSP90 inhibition was investigated by the transfection of small interfering RNA (siRNA). RESULTS: The levels of HSP90 protein expression in cultured angiosarcoma cell lines were markedly increased compared with those in normal tissue cell lines. Immunohistochemical analyses revealed that the expression of HSP90 protein was strongly detected in angiosarcoma tissues compared with that in normal dermal vessels or senile angioma tissues. Ganetespib, an HSP90 inhibitor, with or without taxanes, inhibited the proliferation of angiosarcoma cells via apoptosis in a dose-dependent manner. HSP90 siRNA suppressed the proliferation, migration and invasion of angiosarcoma cells. Knock-down of HSP90 did not suppress vascular endothelial growth factor receptor 2 directly, but selectively suppressed several downstream targets of vascular endothelial growth factor signalling in angiosarcoma cells. CONCLUSIONS: HSP90 could be a novel therapeutic target for angiosarcoma.

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.

The expression profile of the toll-like receptor family in scleroderma dermal fibroblasts.

OBJECTIVES: The toll-like receptor (TLR) family is thought to be expressed in many cell types in the skin and play a role in various diseases. The expression pattern and role of TLRs in systemic sclerosis (SSc) is to be clarified. We investigated the expression profiles of TLR-related genes in SSc fibroblasts, and tried to clarify their roles in the pathogenesis of this disease. METHODS: The expression profile of TLR-related genes was assessed by gene array. Real-time PCR was used to confirm the array result. The protein expression of TLRs and type I collagen was determined by immunoblotting and immunohistochemistry. RESULTS: PCR array revealed that several genes were up- or down-regulated in SSc fibroblasts compared to normal cells. Among them, both mRNA and protein levels of TLR5 and TLR10 were up-regulated in SSc fibroblasts. The transfection of Smad3 siRNA into SSc fibroblasts resulted in the down-regulation of TLR proteins. There was no significant difference in mRNA half-lives of TLR5 and TLR10 between normal and SSc fibroblasts. Immunohistochemical staining revealed that TLRs expression was strongly detected in SSc fibroblasts in vivo. The stimulation of TLR5 signal with flagellin reduced the expression of type I collagen in SSc fibroblasts, but not in normal fibroblasts. CONCLUSIONS: TLR5 and TLR10 expression is increased in SSc fibroblasts in vitro and in vivo, probably at transcript level via the TGF-ß/Smad3 activation. Furthermore, TLR5 itself may have suppressive effects on collagen expression, and its overexpression in SSc fibroblasts may be the negative feedback against tissue fibrosis.

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.

Impaired lymphangiogenesis due to excess vascular endothelial growth factor-D/Flt-4 signalling in the skin of patients with systemic sclerosis.

BACKGROUND: Vascular abnormalities are one of the primary pathological components of systemic sclerosis (SSc). However, it has not been determined if there are also abnormalities in the formation of lymphatic vessels in SSc. OBJECTIVE: To evaluate lymphangiogenic activity in SSc skin. METHODS: The numbers of D2-40-positive lymphatic vessels in skin specimens from healthy control subjects and patients with SSc were counted and compared. Quantitative real-time polymerase chain reaction (PCR) was performed to determine mRNA levels of vascular endothelial growth factor (VEGF)-D and Flt-4 (fms-related tyrosine kinase 4, VEGFR-3, one of the receptors for VEGF-D) in the skin. Serum VEGF-D levels were measured with specific enzyme-linked immunosorbent assays. RESULTSZ: The number of lymphatic vessels in patients with SSc was significantly decreased compared with healthy control subjects. Mean relative transcript levels of FIGF (VEGF-D) and FLT4 (Flt-4) in skin tissue from patients with SSc were significantly increased compared with healthy control subjects. By the analysis of the association between serum VEGF-D levels and the clinical or laboratory features, we found that patients with SSc with higher serum VEGF-D levels more frequently have skin ulcers than those with normal VEGF-D levels. CONCLUSIONS: A systemic increase of VEGF-D, as well as local overexpression of FIGF and FLT4, may be the cause of disturbed lymphangiogenesis in SSc skin and play a role in the pathogenesis of SSc. We showed the possibility that regulation of VEGF-D/Flt-4 signalling could lead to new treatment of skin ulcers in SSc by controlling the formation of lymphatic vessels.

Serum levels of soluble vascular endothelial growth factor receptor-2 in patients with systemic sclerosis.

BACKGROUND: Although vascular endothelial growth factor (VEGF)-A/VEGF receptor 2 (KDR) signalling may play a major role in the microangiopathy of systemic sclerosis (SSc), serum levels of soluble KDR (sKDR) in this disease have not yet been determined. OBJECTIVES: To evaluate the possibility that serum sKDR levels can be a specific disease marker of SSc. METHODS: Serum sKDR levels of 42 patients with SSc, 10 patients with Raynaud's phenomenon (RP) and 22 healthy controls were measured with specific enzyme-linked immunosorbent assays. Quantitative real-time polymerase chain reaction (PCR) was performed to determine KDR mRNA levels. RESULTS: In females, the serum sKDR levels were significantly higher in patients with SSc, especially limited cutaneous SSc, than in patients with RP or healthy controls. Quantitative real-time PCR with RNA from skin sections revealed that KDR mRNA levels were also increased in the skin of patients with SSc with elevated serum sKDR levels. A significantly lower prevalence of pulmonary fibrosis, higher percentage vital capacity, and a higher incidence of telangiectasia were seen in female patients with SSc with elevated serum sKDR levels than those with normal levels. CONCLUSIONS: These results suggest that the skin can be one of the sources of elevated serum sKDR levels, and that serum sKDR levels are useful for diagnosis and may be a marker of microangiopathy in patients with SSc, especially females. The VEGF-A/KDR signalling system may be involved in the pathogenesis of the disease.