Large-Scale Proteomic Characterization of Melanoma Expressed Proteins Reveals Nestin and Vimentin as Biomarkers That Can Potentially Distinguish Melanoma Subtypes

Melanoma
is an aggressive type of skin cancer, which accounts for
only 4% of skin cancer cases but causes around 75% of skin cancer
deaths. Currently, there is a limited set of protein biomarkers that
can distinguish melanoma subtypes and provide an accurate prognosis
of melanoma. Thus, we have selected and profiled the proteomes of
five different melanoma cell lines from different stages of progression
in comparison with a normal melanocytes using tandem mass spectrometry.
We also profiled the proteome of a solid metastatic melanoma tumor.
This resulted in the identification of 4758 unique proteins, among
which ∼200–300 differentially expressed proteins from
each set were found by quantitative proteomics. Correlating protein
expression with aggressiveness of each melanoma cell line and literature
mining resulted in the final selection of six proteins: vimentin,
nestin, fibronectin, annexin A1, dipeptidyl peptidase IV, and histone
H2A1B. Validation of nestin and vimentin using 40 melanoma samples
revealed pattern of protein expression can help predict melanoma aggressiveness
in different subgroups of melanoma. These results, together with the
combined list of 4758 expressed proteins, provide a valuable resource
for selecting melanoma biomarkers in the future for the clinical and
research community.