Novel ex vivo disease model for extramammary Paget's disease using the cancer tissue-originated spheroid method.

BACKGROUND: Extramammary Paget's disease (EMPD) is a rare skin cancer that frequently occurs in the anogenital region in the elderly. Prognosis in patients with metastatic EMPD is poor as EMPD treatment has advanced little in recent years, primarily because no EMPD cell line has been established. OBJECTIVE: We aimed to establish an ex vivo EMPD disease model using the cancer tissue-originated spheroid (CTOS) method, which is used to prepare and culture primary cancer cells while maintaining cell-cell contact. METHODS: Thirteen samples from 12 EMPD patients were obtained. CTOSs were prepared and cultured using CTOS method. Histopathological examination of the CTOSs was performed. We investigated optimum medium conditions and effects of growth factors for CTOS growth. Chemo-sensitivity assays were conducted. RESULTS: CTOSs were successfully prepared from 3 primary lesions and 2 metastatic lymph nodes. Of these, 2 CTOSs (EMPD-3 and EMPD-4) could be maintained and passaged long term ex vivo. Following transplantation of CTOSs to NOD/Scid mice, CTOS-derived xenotumors exhibited ductal formation, indicating that CTOSs retained the original tumor characteristics. Chemo-sensitivity assays revealed that docetaxel significantly inhibited EMPD-3 growth in a dose-dependent manner, whereas EMPD-4 was not clearly inhibited. These findings indicate the heterogeneity of EMPD and potential use of chemosensitivity assays with patient-derived CTOS to select the most effective drugs for each patient. CONCLUSION: To our knowledge, this study represents the first establishment of an ex vivo-EMPD disease model involving conventional cell lines. EMPD CTOSs might be useful for developing new therapeutic strategies.

CD163-positive macrophage infiltration predicts systemic involvement in sarcoidosis.

BACKGROUND: Sarcoidosis is a chronic and systemic inflammatory disease, in which patients present with noncaseating epithelioid granulomas. Cutaneous lesions of sarcoidosis develop in 9% to 35% of all sarcoidosis patients and comprise various clinical subtypes. It usually affects multiple organs and has a variable clinical course; this is called systemic sarcoidosis (SS). However, occasionally, it only affects the skin and is then called cutaneous sarcoidosis (CS). Recent observations suggest that serum levels of soluble CD163 correlate with immune cell activity in sarcoidosis patients; however, the contribution of M1 and M2 macrophages toward disease progression remains unclear. METHODS: We evaluated macrophage phenotypes histopathologically using skin biopsy samples obtained from patients with CS (n = 8) and SS (n = 31) and performed immunostaining with CD68, iNOS (M1 macrophages), PD-L1, and CD163 (M2 macrophages). RESULTS: The density of CD163-positive cells in the SS group was significantly higher than that in the CS group. There was no significant correlation between the CD163 (+) cell density and serum angiotensin-converting enzyme level, serum calcium, or tuberculin reaction. CONCLUSIONS: Immunostaining for CD163 may be a novel and useful marker to predict systemic involvement in patients with cutaneous lesions of epithelioid granulomas.

Nanoparticle-mediated local delivery of pioglitazone attenuates bleomycin-induced skin fibrosis.

BACKGROUND: Nanoparticle-loaded delivery systems have attracted much attention recently. Poly(lactic-co-glycolic acid) (PLGA) is one of the most successful biodegradable polymers for biomedical applications. There are only a few studies on the treatment of dermal fibrosis with sustained-release drugs. Peroxisome proliferator-activated receptor-γ (PPAR-γ) plays an important role in endogenous anti-fibrotic defense mechanisms. Recent studies have suggested that pioglitazone, a synthetic PPAR-γ activator, has effects beyond reducing blood sugar and it can reduce fibrosis and inflammation when used systemically. OBJECTIVE: We aimed to assess the effects of local injections of pioglitazone-loaded PLGA nanoparticles (PGN-NP) on an experimental sclerosis and to demonstrate the in vivo pharmacokinetics of subcutaneously administered PLGA nanoparticles. METHODS: Locally injectable PGN-NP were prepared and subcutaneously administered to bleomycin (BLM)-induced scleroderma model mice. The effect of pioglitazone was also evaluated with cultured fibroblasts. Coumarin-6-loaded fluorescent PLGA nanoparticles (FL-NP) and silicon naphthalocyanine-loaded near-infrared PLGA nanoparticles (NIR-NP) were used to demonstrate in vitro cellular uptake by cultured fibroblasts and the in vivo pharmacokinetics of subcutaneously administered nanoparticles. RESULTS: Weekly subcutaneous injections of PGN-NP attenuated skin fibrosis in BLM-induced scleroderma model mice. Pioglitazone significantly suppressed migration ability and TGF-ß-mediated myofibroblast differentiation in cultured fibroblasts. FL-NP were internalized into cultured fibroblasts within 60 min, and PGN-NP-primed fibroblasts expressed anti-fibrotic phenotypes. Subcutaneously injected NIR-NP remained in the vicinity of the injection site more than non-particulate silicon naphthalocyanine. CONCLUSION: These results provide a basis for the development of new treatments for dermal fibrosis and a better understanding of the potential of PLGA nanoparticles in dermatology.

Podoplanin expression in peritumoral keratinocytes predicts aggressive behavior in extramammary Paget's disease.

BACKGROUND: Recent studies have demonstrated podoplanin expression in several tumors, which has been associated with lymph node metastasis and poor prognosis. Podoplanin expression in peritumoral cells such as cancer-associated fibroblasts also correlates with tumor progression in several cancers. However, podoplanin expression and its association with extramammary Paget's disease (EMPD) remain unclear. OBJECTIVE: In this study, we examined whether the presence of podoplanin expression in tumor cells or peritumoral basal keratinocytes correlated with aggressive behavior in patients with EMPD and investigated the mechanisms of podoplanin-mediated tumor invasion in this disorder. METHODS: Skin samples of 37 patients with EMPD were investigated by immunohistochemical analysis. The functions of podoplanin in keratinocytes were examined in vitro by RT-PCR and with invadopodia gelatin-degradation assays using HaCaT cells. RESULTS: Podoplanin was not identified in tumor cells in all cases. Podoplanin expression in peritumoral basal keratinocytes was observed in 25 patients (67.6%). In in situ EMPD, 50% of cases (9 in 18) exhibited podoplanin-positive keratinocytes, whereas 84.2% (16 in 19) demonstrated positive staining in invasive EMPD (P<0.05). Podoplanin expression in peritumoral keratinocytes was also associated with tumor thickness (P<0.005). By immunohistochemical analysis, podoplanin-positive peritumoral keratinocytes were found to be negative for E-cadherin, one of the major adhesion molecules of keratinocytes, which might contribute to tumor invasion into the dermis through a crack in the basal cell layer induced by down-regulation of cell adhesion therein. We further found that podoplanin-positive keratinocytes exhibited invadopodia, which are thought to function in the migration of cancer cells through tissue barriers, indicating that podoplanin-positive peritumoral basal keratinocytes might assist tumor invasion by degrading the extracellular matrix. CONCLUSION: The presence of podoplanin expression in peritumoral keratinocytes correlates with aggressive behavior in EMPD and might therefore serve as a useful prognostic marker for patients with EMPD.

Malignant melanoma showing a rapid response to nivolumab.

Malignant melanoma is a highly aggressive skin tumour, with a recent rise in incidence. Nivolumab is a recently developed anti-programmed cell death-1 immune checkpoint inhibitor and its usage has resulted in a significant improvement in the overall survival of patients with metastatic melanomas. We report a case of advanced melanoma that showed a significant and rapid response to nivolumab treatment. The patient displayed multiple melanoma-associated vitiligo prior to treatment; this symptom was theorised to indicate potentially immunoreactive melanoma and the need for nivolumab. In addition, interferon-ß was injected prior to nivolumab treatment. The significant rapid response to nivolumab suggested the induction of a marked immune response against melanoma by interferon-ß. Therefore, interferon-ß could be a useful and effective adjuvant for nivolumab therapy.