Thymosin β‐10 expression in melanoma cell lines and melanocytic lesions: A new progression marker for human cutaneous melanoma

When screening a subtraction library for sequences that were specifically expressed in highly metastatic human melanoma cell lines, a cDNA clone was isolated encoding thymosin β‐10. We found that expression of thymosin β‐10 mRNA was associated with metastatic behavior of various human melanoma cell lines in nude mice. Furthermore, Northern blot analysis showed that also in freshly harvested human melanocytic lesions thymosin β‐10 was differentially expressed. Although expression of thymosin β‐10 was also examined in other non‐melanoma model systems and materials, no clear relation could be established with metastatic potential or malignancy. Therefore, we conclude that thymosin β‐10 can be considered as a new progression marker for human cutaneous melanoma.