Purpose: Patient survival in uveal melanoma may benefit from earlier recognition of potential metastases to the liver, but as yet, proper markers indicating metastases are not available. Identification of metastasis markers would therefore be of great value. The proteins that are expressed in two cell lines originating from two liver metastases were compared with the proteins expressed in a cell line obtained from the primary uveal melanoma of the same patient, to identify proteins that play a role in tumor progression as well as proteins that are expressed specifically in metastases.
Methods: Protein analysis was performed by using two-dimensional gel electrophoresis. A subset of proteins was subsequently identified with mass spectrometry.
Results: A set of 24 proteins was differentially expressed in both of the two metastatic cell lines compared with the cell line derived from the primary tumor. These proteins were subdivided into groups according to cellular function, with important roles in tumor development.
Conclusions: Tumor progression and development of metastases is a multicomplex system. Comparing protein expression in two cell lines derived from metastases with a cell line derived from a primary uveal melanoma from the same patient identified proteins involved in tumor progression, and proteins specifically expressed in the metastases, which have the potential of becoming clinically useful biomarkers.