Establishment and Characterisation of Human Clear Cell Sarcoma and Malignant Melanoma Cell Lines.

Background/aim: Clear cell sarcoma of soft tissue (CCSST) and conventional malignant melanoma (MM) are rare and aggressive tumours with similarities in morphology and the expression of melanocytic markers.

Materials And Methods: We established two CCSST cell lines (FU-CCSST-1 and FU-CCSST-2) from soft tissues of the patella and supraclavicular. A MM cell line (FU-MM-1) was established from lymph node metastases of subungual malignant melanoma.

Results: FU-CCSST-2 cells were transplantable to immunodeficient mice. Immunohistochemical studies demonstrated tumour cells were negative for cytokeratin AE1/AE3 and positive for S100 protein, HMB45, Melan-A, CD146 and SOX10 in all specimens. FU-CCSST-1 and FU-CCSST-2 harboured t(12;22)(q13;q12) translocations with expression of the EWSR1/ATF1 fusion gene. FU-MM-1 demonstrated loss of the short arm of chromosome 9 and harboured wild-type BRAF (codon 469 and 600) and NRAS (codon 12, 13 and 61).

Conclusion: We report the establishment and characterisation of CCSST and MM cell lines that may have utility in the study of pathogenic mechanisms and development of novel therapeutic reagents.