Affinity Proteomics Exploration of Melanoma Identifies Proteins in Serum with Associations to T-Stage and Recurrence

Abstract

BACKGROUND: Blood-based proteomic profiling may aid and expand our understanding of diseases and their different phenotypes. The aim of the presented study was to profile serum samples from patients with malignant melanoma using affinity proteomic assays to describe proteins in the blood stream that are associated to stage or recurrence of melanoma. MATERIAL AND METHODS: Multiplexed protein analysis was conducted using antibody suspension bead arrays. A total of 232 antibodies against 132 proteins were selected from (i) a screening with 4595 antibodies and 32 serum samples from melanoma patients and controls, (ii) antibodies used for immunohistochemistry, (iii) protein targets previously related with melanoma. The analysis was performed with 149 serum samples from patients with malignant melanoma. Antibody selectivity was then assessed by Western blot, immunocapture mass spectrometry, and epitope mapping. Lastly, indicative antibodies were applied for IHC analysis of melanoma tissues. RESULTS: Serum levels of regucalcin (RGN) and syntaxin 7 (STX7) were found to be lower in patients with both recurring tumors and a high Breslow's thickness (T-stage 3/4) compared to low thickness (T-stage 1/2) without disease recurrence. Serum levels of methylenetetrahydrofolate dehydrogenase 1-like (MTHFD1L) were instead elevated in sera of T3/4 patients with recurrence. The analysis of tissue sections with S100A6 and MTHFD1L showed positive staining in a majority of patients with melanoma, and S100A6 was significantly associated to T-stage. CONCLUSIONS: Our findings provide a starting point to further study RGN, STX7, MTHFD1L and S100A6 in serum to elucidate their involvement in melanoma progression and to assess a possible contribution to support clinical indications.

Proteomic profile of melanoma cell‐derived small extracellular vesicles in patients’ plasma: a potential correlate of melanoma progression

“…The search for biomarkers of melanoma progression and response to therapy including recent genomics or other “omics” approaches has led to the discovery of numerous promising proteins (reviewed in (Gowda et al., 2020; Rodriguez‐Cerdeira et al., 2018)). However, none of these potential biomarkers have been validated so far, and only soluble lactic dehydrogenase (sLDH) remains as the protein that correlates with the disease burden in some patients with metastatic melanoma (Byström et al., 2017). Recent attempts at establishing correlations between levels of sLDH and any specific molecular, immunological or metabolic phenotypes, including immune cell infiltrate in the tumour, point mutations, DNA copy number, promoter methylation, RNA expression or protein expression in melanoma metastases have been not been successful (Gowda et al., 2020).…”

“…Factors known to be involved in angiogenesis, immune suppression, modification of stroma, capture of cancer cells in lymph nodes and tumour cell progression have been identified in sEV from the plasma of melanoma patients by us and others (Alegre et al., 2016; Gowda et al., 2020; Hood, 2019; Sharma et al., 2020). Several previous studies suggested that the use of EV, especially tumour cell‐derived sEV (TEX), might be a more promising approach to the discovery and development of melanoma‐associated biomarkers than strategies dependent on conventional tumour tissue examination or on measuring levels of soluble factors in patients’ plasma (Byström et al., 2017; Rodriguez‐Cerdeira et al., 2018; The TCGA Research Network).…”

Protein profiles in plasma: Development from infancy to 5 years of age

“…This method has previously been applied in both pediatric and adult cohorts in other contexts such as childhood asthma and malaria, [12,30] liver and kidney disease, [11,31] nervous system/neurodegenerative disease, [32,33] and cancer. [34] Although our study included a large number of children, the number of children per lifestyle group was too small to allow for analysis stratified by exposure, such as vaccination and breast feeding or outcome such as sensitization to allergens. An association with sex in the development of plasma proteins cannot be ruled out; however, the proportions of females and males were reasonably balanced, also between the lifestyle groups (Table 1).…”

“…This method has previously been applied in both pediatric and adult cohorts in other contexts such as childhood asthma and malaria, [ 12,30 ] liver and kidney disease, [ 11,31 ] nervous system/neurodegenerative disease, [ 32,33 ] and cancer. [ 34 ]…”

RAGE Signaling in Melanoma Tumors

“…The expression of S100A6 was described in cutaneous and extracutaneous lesion including melanocytic nevi and malignant melanoma [179]. S100A6 is overexpressed in Spitz nevi, melanocytic nevi, and melanomas [160]; in fact, tissue analysis of melanoma patients revealed that most melanomas showed positive staining for S100A6 [161]. Interestingly, many studies have suggested a role of S100A6 in metastasis, although the exact metastatic mechanism is not specified.…”