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.

Loss-of-function mutations in the gene encoding filaggrin underlie a Japanese family with food-dependent exercise-induced anaphylaxis.

BACKGROUND: Food-dependent exercise-induced anaphylaxis (FDEIA) is a serious food allergy in which anaphylaxis develops when exercise is performed within several hours after food intake. The precise mechanism underlying allergic sensitization in FDEIA has been an important issue but remains poorly understood. OBJECTIVES: We aimed to elucidate the pathomechanism including the route of allergen sensitization involved in FDEIA. METHODS: A Japanese family with wheat-dependent exercise-induced anaphylaxis (WDEIA), a specific form of FDEIA, were clinically examined. Mutation analysis of the gene encoding filaggrin (FLG) was also performed. RESULTS: Two of the family members were confirmed as WDEIA on the basis of their medical history and positive provocation test results. Notably, the two affected individuals in the family had concomitant ichthyosis vulgaris. Mutation analysis of FLG revealed that they carry one or more loss-of-function mutations that have not been described in the Japanese population. CONCLUSION: These results indicate that FLG mutations might be involved in the pathogenesis of WDEIA in the present case.

MUC5AC expression correlates with invasiveness and progression of extramammary Paget's disease.

BACKGROUND: Patients with in situ extramammary Paget's disease (EMPD) tend to have a good prognosis, although dermal invasion and metastasis are associated with significantly increased morbidity and mortality. Previous studies have addressed mechanisms underlying the EMPD pathogenesis; however, no molecular markers that reflect invasiveness or progression have been established. OBJECTIVE: This study aims to identify a reliable marker for predicting the risk of invasion and metastasis in EMPD. METHODS: We performed an initial microarray screening for in situ, invasive or metastatic lymph node lesions of EMPD. We analysed 44 specimens from 38 primary EMPD cases by immunohistochemical staining. RESULTS: We found that expressions of MUC5AC directly correlate with invasion and prognosis. Labelling rates of tumour cells were scored by staining intensity on a four-tiered scale (- to 3+) to investigate the correlation between the expression score of these molecular markers and the type of EMPD lesion. All the specimens scored positive (3+) for MUC1 and negative (-) for MUC6. MUC5AC expression was detected in 19 of 44 (43.2%) specimens. Invasive lesions and metastatic lymph nodes tended to express MUC5AC significantly higher than in situ lesions (P < 0.01). MUC2 was positive in 10 specimens (22.7%). There was no significant difference between the degree of MUC2 expression and invasiveness. CONCLUSION: The degree of MUC5AC expression may correlate with the invasiveness and progression of EMPD, and may be a useful marker for identifying high-risk EMPD cases.

The role of PEDF in tumor growth and metastasis.

Pigment epithelium-derived factor (PEDF), one of the non-inhibitory serpines, is widely expressed throughout the body. Although PEDF was initially identified as a neuronal differentiation factor, more attention has been paid to its anti-angiogenic activity. Additionally, recent researches have demonstrated that PEDF has an anti-tumor effect against several human neoplasms. This review focuses on the pathological role of PEDF in tumors, especially tumor growth and metastasis. PEDF is an endogenous anti-tumor factor and its clinical application seems quite promising, although there is much to be further investigated.

Epidermolysis bullosa acquisita associated with psoriasis vulgaris.

We report a case of epidermolysis bullosa acquisita (EBA) associated with psoriasis vulgaris. A 71-year-old woman with psoriasis vulgaris developed subepidermal blisters on the extremities. Direct immunofluorescence demonstrated linear deposit of IgG at the basement membrane zone, which bound to the dermal side of normal human skin split with 1 mol/L NaCl. Immunoblot analysis using recombinant full-length type VII collagen detected a 290-kDa band, confirming the diagnosis of EBA. A literature search for previous reports found a few cases of EBA associated with psoriasis, and all cases, including our own, presented with widespread inflammatory vesicles and bullae, and responded to conventional therapy with corticosteroids and immunosuppressive agents. This study suggests that western blotting using recombinant full-length type VII collagen could be useful for diagnosis of EBA, and that EBA associated with psoriasis may have a tendency to be the inflammatory type.

Eccrine porocarcinoma and Bowen's disease arising in a seborrhoeic keratosis.

An association between seborrhoeic keratosis (SK) and malignant tumours is considered to be rare. We observed a case of eccrine porocarcinoma and Bowen's disease (BD) occurring synchronously, forming one lesion in a SK on the abdomen. It is controversial whether malignant neoplasms arising in SK occur only by chance or if pre-existing SK plays a role in pathogenesis. This case suggests an implication of pre-existing SK in the subsequent development of both BD and eccrine porocarcinoma.