Epithelioid sarcoma with multiple lesions on the left arm: a case report.

BACKGROUND: Epithelioid sarcoma is a rare, high-grade malignant tumor of the soft tissue. The incidence of local recurrence, regional lymph node involvement, and distant metastases is high. Epithelioid sarcoma is most often seen in adolescents and young adults. In the early stage before the development of full clinical features, epithelioid sarcoma is often misdiagnosed as a benign disease such as granuloma. CASE PRESENTATION: We report a case of a 74-year-old Japanese woman whose epithelioid sarcoma was initially misdiagnosed as fungal infection. Rebiopsy revealed the proliferation of atypical polygonal or oval epithelioid cells in the dermis and lymphocyte infiltration through the dermis. Immunohistochemically, the tumor cells were positive for vimentin, cell adhesion molecule 5.2, epithelial membrane antigen, and E26-related gene. The nuclear expression of integrase interactor 1 was lost in the tumor cells. CONCLUSIONS: We encountered a rare case of epithelioid sarcoma and had difficulty in making the correct diagnosis. We suggest that in patients whose lesions are resistant to conventional treatments, repeat biopsy and immunohistochemical studies should be considered to rule out rare epithelioid sarcoma.

CD147-targeting siRNA inhibits cell-matrix adhesion of human malignant melanoma cells by phosphorylating focal adhesion kinase.

CD147/basigin, highly expressed on the surface of malignant tumor cells including malignant melanoma (MM) cells, plays a critical role in the invasiveness and metastasis of MM. Metastasis is an orchestrated process comprised of multiple steps including adhesion and invasion. Integrin, a major adhesion molecule, co-localizes with CD147/basigin on the cell surface. Using the human MM cell line A375 that highly expresses CD147/basigin, we investigated whether CD147/basigin is involved in adhesion in association with integrin. CD147/basigin was knocked-down using siRNA targeting CD147 to elucidate the role of CD147/basigin. Cell adhesion was evaluated by adhesion assay on matrix-coated plates. The localization of integrin was inspected under a confocal microscope and the expression and phosphorylation of focal adhesion kinase (FAK), a downstream kinase of integrin, were examined by western blot analysis. Silencing of CD147/basigin in A375 cells by siRNA induced the phosphorylation of FAK at Y397. Integrin identified on the surface of parental cells was distributed in a speckled fashion in the cytoplasm of CD147 knockdown cells, resulting in morphological changes from a round to a polygonal shape with pseudopodial protrusions. Silencing of CD147/basigin in A375 cells clearly weakened their adhesiveness to collagen I and IV. Our results suggest that CD147/basigin regulates the adhesion of MM cells to extracellular matrices and of integrin ß1 signaling via the phosphorylation of FAK.