Melanogenesis-inducing effect of cirsimaritin through increases in microphthalmia-associated transcription factor and tyrosinase expression.
Kim, HJ; Kim, IS; Dong, Y; Lee, IS; Kim, JS; Kim, JS; Woo, JT; Cha, BY
International journal of molecular sciences
16
8772-88
2015
Show Abstract
The melanin-inducing properties of cirsimaritin were investigated in murine B16F10 cells. Cirsimaritin is an active flavone with methoxy groups, which is isolated from the branches of Lithocarpus dealbatus. Tyrosinase activity and melanin content in murine B16F10 melanoma cells were increased by cirsimaritin in a dose-dependent manner. Western blot analysis revealed that tyrosinase, tyrosinase-related protein (TRP) 1, TRP2 protein levels were enhanced after treatment with cirsimaritin for 48 h. Cirsimaritin also upregulated the expression of microphthalmia-associated transcription factor (MITF) after 24 h of treatment. Furthermore, cirsimaritin induced phosphorylation of cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB) in a dose-dependent manner after treatment for 15 min. The cirsimaritin-mediated increase of tyrosinase activity was significantly attenuated by H89, a cAMP-dependent protein kinase A inhibitor. These findings indicate that cirsimaritin stimulates melanogenesis in B16F10 cells by activation of CREB as well as upregulation of MITF and tyrosinase expression, which was activated by cAMP signaling. Finally, the melanogenic effect of cirsimaritin was confirmed in human epidermal melanocytes. These results support the putative application of cirsimaritin in ultraviolet photoprotection and hair coloration treatments. | 25903150
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Malignant PEComa of the adrenal gland.
Lau, Sean K
Pathol. Res. Pract., 208: 113-7 (2012)
2012
Show Abstract
Perivascular epithelioid cell neoplasms, also known as PEComas, are unique mesenchymal tumors exhibiting perivascular epithelioid cell differentiation, characterized by a mixed myogenic and melanocytic phenotype. PEComas arising in visceral organs outside of the kidney, liver, and lung are rare, and often pose problems in diagnosis. Examples of this neoplasm originating in the adrenal gland are limited. The present report details the clinical and pathologic features of an unusual case of a pure epithelioid PEComa (epithelioid angiomyolipoma) of the adrenal gland exhibiting clinically malignant behavior in the form of pulmonary metastases, a feature not previously described in tumors of this site. The diagnosis was supported by immunohistochemical studies demonstrating expression of myoid and melanocytic antigens. The present case serves to emphasize the potential of PEComa for clinically aggressive behavior and the importance of distinguishing this tumor from other epithelioid neoplasms that are more commonly encountered in the adrenal gland. | 22154607
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