The ultraviolet (UV) component of solar radiation is the major driving force of skin
carcinogenesis. Most of studies on UV
carcinogenesis actually focus on DNA damage while their
proteome-damaging ability and its contribution to skin
carcinogenesis have remained largely underexplored. A redox proteomic analysis of oxidized
proteins in solar-induced neoplastic skin lesion and perilesional areas has been conducted showing that the
protein oxidative burden mostly concerns a selected number of
proteins participating to a defined set of functions, namely: chaperoning and stress response; protein folding/refolding and
protein quality control; proteasomal function; DNA damage repair;
protein- and vesicle-trafficking; cell architecture, adhesion/extra-cellular matrix (ECM) interaction; proliferation/oncosuppression; apoptosis/survival, all of them ultimately concurring either to structural damage repair or to damage detoxication and stress response. In peri-neoplastic areas the oxidative alterations are conducive to the persistence of genetic alterations, dysfunctional apoptosis surveillance, and a disrupted extracellular environment, thus creating the condition for transformant clones to establish, expand and progress. A comparatively lower burden of oxidative damage is observed in neoplastic areas. Such a finding can reflect an adaptive selection of best fitting clones to the sharply
pro-oxidant neoplastic environment. In this context the DNA damage response appears severely perturbed, thus sustaining an increased
genomic instability and an accelerated rate of neoplastic evolution. In conclusion UV radiation, in addition to being a
cancer-initiating agent, can act, through
protein oxidation, as a
cancer-promoting agent and as an inducer of
genomic instability concurring with the neoplastic progression of established lesions.