Proteomic analysis of stratum corneum in Cutaneous T-Cell Lymphomas and psoriasis.

Stratum corneum collected by tape stripping from 10 and 24 subjects with cutaneous T-cell lymphomas (CTCL) or psoriasis, respectively, were compared using quantitative label-free mass spectrometry analysis. A non-supervised statistical analysis (Posneg NMF) based on 352 differentially expressed proteins in both CTCL and psoriasis samples was able to separate the two disease groups and finally able to identify a set of 112 proteins that contributed most and significantly to the separation when compared to non-lesional samples. In addition, Luminex assay revealed that the increase in the amount of chemokines related to the inflammatory response, and immune cell infiltration and recruitment in lesional stratum corneum in CTCL, including CXCL8, CXCL9, CXCL10, CCL27, TNF and sICAM-1 was in agreement with published data on entire skin biopsies. Proteome analysis using quantitative methods including mass spectrometry and Luminex technology offered the possibility to investigate the relevant protein signature in CTCL and may be helpful to diagnose and investigate the efficacy of treatments in clinical investigations using non-invasive methods in future.

Monitoring UV-induced signalling pathways in an ex vivo skin organ culture model using phospho-antibody array.

We investigated UV-induced signalling in an ex vivo skin organ culture model using phospho-antibody array. Phosphorylation modulations were analysed in time-course experiments following exposure to solar-simulated UV and validated by Western blot analyses. We found that UV induced P-p38 and its substrates, P-ERK1/2 and P-AKT, which were previously shown to be upregulated by UV in cultured keratinocytes and in vivo human skin. This indicates that phospho-antibody array applied to ex vivo skin organ culture is a relevant experimental system to investigate signalling events following perturbations. As the identified proteins are components of pathways implicated in skin tumorigenesis, UV-exposed skin organ culture model could be used to investigate the effect on these pathways of NMSC cancer drug candidates. In addition, we found that phospho-HCK is induced upon UV exposure, producing a new candidate for future studies investigating its role in the skin response to UV and UV-induced carcinogenesis.