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- Briggs, Jon J., et al.
(författare)
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Cystatin E/M suppresses legumain activity and invasion of human melanoma
- 2010
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Background: High activity of cysteine proteases such as legumain and the cathepsins have been shown to facilitate growth and invasion of a variety of tumor types. In breast cancer, several recent studies have indicated that loss of the cysteine protease inhibitor cystatin E/M leads to increased growth and metastasis. Although cystatin E/M is normally expressed in the skin, its role in cysteine protease regulation and progression of malignant melanoma has not been studied. Methods: A panel of various non-melanoma and melanoma cell lines was used. Cystatin E/M and C were analyzed in cell media by immunoblotting and ELISA. Legumain, cathepsin B and L were analyzed in cell lysates by immunoblotting and their enzymatic activities were analyzed by peptide substrates. Two melanoma cell lines lacking detectable secretion of cystatin E/M were transfected with a cystatin E/M expression plasmid (pCST6), and migration and invasiveness were studied by a Matrigel invasion assay. Results: Cystatin E/M was undetectable in media from all established melanoma cell lines examined, whereas strong immunobands were detected in two of five primary melanoma lines and in two of six lines derived from patients with metastatic disease. Among the four melanoma lines secreting cystatin E/M, the glycosylated form (17 kD) was predominant compared to the non-glycosylated form (14 kD). Legumain, cathepsin B and L were expressed and active in most of the cell lines, although at low levels in the melanomas expressing cystatin E/M. In the melanoma lines where cystatin E/M was secreted, cystatin C was generally absent or expressed at a very low level. When melanoma cells lacking secretion of cystatin E/M were transfected with pCST6, their intracellular legumain activity was significantly inhibited. In contrast, cathepsin B activity was not affected. Furthermore, invasion was suppressed in cystatin E/M over-expressing melanoma cell lines as measured by the transwell Matrigel assay. Conclusions: These results suggest that the level of cystatin E/M regulates legumain activity and hence the invasive potential of human melanoma cells.
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| 2. |
- Harbst, Katja, et al.
(författare)
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The genetic evolution of melanoma
- 2018
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Ingår i: Melanoma : A Modern Multidisciplinary Approach - A Modern Multidisciplinary Approach. - Cham : Springer International Publishing. - 9783319783093 - 9783319783109 ; , s. 105-114
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Bokkapitel (refereegranskat)abstract
- Melanoma tumors are driven by a hyperactivated mitogen-activated protein kinase (MAPK) signalling pathway, and therefore can generally be classified by mutations within the B-Raf proto-oncogene (BRAF), RAS family of proto-oncogenes, neurofibromin 1 (NF1), or other genes. At the transcriptional level, several genetic classifications of melanoma have converged on the distinction between melanogenesis (previously microphthalmia) associated transcription factor (MITF)-low and MITF-high phenotypes and expression of immune-related genes. Mutation-based melanoma subtypes are not prognostic, nor are they associated to transcriptomic subtypes, which are in turn prognostic. Intratumoral heterogeneity of melanoma cells adds another layer of complexity, with recent findings of mutational and transcriptional heterogeneity within melanoma tumors. Furthermore, multiple genetic changes have been associated with different stages of melanoma progression. Mutational signatures may also be differentiated at early and late stages of melanoma progression.
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